Cognitive, emotional, and behavioral characterizations have been reported for patients with a few chromosomal imbalances, but not for patients with a 13q deletion. We report the neuropsychological profile and specific linguistic, visual, spatial, constructional, and behavioral disabilities of a young man with a de novo chromosome 13 deletion (13)(q21.32)(q31.1). Karyotyping at 550 G-band resolution showed that the patient's parents did not share the deletion. According to array-comparative genomic hybridization, the deletion spanned about 14 Mb and included 27 genes. A fluorescence in situ hybridization assay revealed an intact 13q telomere on the partially deleted chromosome. The patient had multiple morphologic and ophthalmologic anomalies. A brain magnetic resonance imaging study did not show gross brain defects. Neuropsychological testing showed an acceptable use of everyday language, but mild mental retardation, executive dysfunction, and very poor performance on visual, visuospatial, and constructional tasks. Establishing a neuropsychological profile for a patient with a specific genetic defect can help clinicians, parents, and teachers work to meet the patient's medical, academic, and behavioral needs.
Stroke is the leading cause of adult disability in the western world. Consensus has built over the last few years regarding the usefulness of training to improve motor disability resulting from stroke. Until recently, there were no accepted strategies to enhance the beneficial effects of training. However, the combination of basic and clinical science data over the last few years is changing this picture, and is highly relevant to the field of neurorehabilitation. Human studies in both healthy individuals and patients after brain damage demonstrate as a proof of principle that somatosensory input, cortical stimulation, interhemispheric interactions, and pharmacologic interventions can modulate cortical plasticity in neurorehabilitation after stroke. These findings strongly suggest directions in the development of novel strategies to enhance training effects on motor recovery. The intent of this review is to describe these strategies, the basic science principles on which they are based, and the clinical applications that have emerged so far.
A 1977 Swiss case study is presented in English translation: a mute child with infantile autism is taught to speak starting at the relatively late age of 6. The author, who is the primary therapist and the child's father, details the conditioning procedure, discusses theoretical considerations in speech acquisition, and outlines the limits of the training. The author and translator update the child's status and add commentary.
This is the first case report of a comprehensive neuropsychologic examination of an older man with the fragile X-associated tremor-ataxia syndrome (FXTAS).
FXTAS, a newly identified phenotype affecting older male carriers of the fragile X premutation allele, is a progressive disorder marked by gait ataxia, action tremor, peripheral neuropathy, executive cognitive deficits, generalized brain atrophy, and neuronal and astrocytic intranuclear inclusion bodies throughout the brain. The patient previously had undergone neurologic evaluation, molecular analysis, and magnetic resonance imaging.
The patient was administered a neuropsychologic examination, assessing motor and somatosensory functioning, visual and spatial functioning, speech and language, attention, executive abilities, learning and memory, and reasoning.
The patient showed a pattern of cognitive impairment characterized by essentially normal speech and language, moderately impaired control of attention, and moderate to severe deficits in working memory, executive functioning, and both declarative and procedural learning. Visual and spatial abilities were relatively unimpaired, and verbal reasoning was only mildly deficient.
The findings suggest that a cognitive disorder, with especially marked executive cognitive function and memory deficits, accompanies FXTAS. The findings in FXTAS are compared with those in several other neurodegenerative disorders.
To investigate whether patients with alcohol-related Korsakoff syndrome (KR) have emotion-specific or general deficits in multicategoric classification performance.
Earlier studies have shown reduced performance in classifying stimuli according to their emotional valence in patients with KS. However, it is unclear whether such classification deficits are of emotion-specific nature or whether they can also occur when nonemotional classifications are demanded.
In this study, we examined 35 patients with alcoholic KS and 35 healthy participants with the Emotional Picture Task (EPT) to assess valence classification performance, the Semantic Classification Task (SCT) to assess nonemotional categorizations, and an extensive neuropsychologic test battery.
KS patients exhibited lower classification performance in both tasks compared with the healthy participants. EPT and SCT performance were related to each other. EPT and SCT performance correlated with general knowledge and EPT performance in addition with executive functions.
Our results indicate a common underlying mechanism of the patients' reductions in emotional and nonemotional classification performance. These deficits are most probably based on problems in retrieving object and category knowledge and, partially, on executive functioning.
Many patients with systemic lupus erythematosus (SLE) have working memory deficits. Few studies have evaluated working memory performance and neurometabolite profile using magnetic resonance spectroscopy in SLE.
We gave the Paced Auditory Serial Addition Test (PASAT), a measure of working memory, to 73 patients with SLE. We calculated total score, dyads, chunking, and cognitive fatigue. Using magnetic resonance spectroscopy, we determined the ratio of choline to creatine (Ch/Cr) in normal-looking right and left frontal lobe white matter.
Twenty-nine percent of patients showed impaired working memory on the PASAT. Total PASAT score inversely correlated with right and left frontal white matter Ch/Cr. Left frontal white matter Ch/Cr correlated with percent chunking and inversely correlated with total and percent dyads. Right frontal white matter Ch/Cr correlated with percent chunking and inversely correlated with total and percent dyads. There was no relationship between cognitive fatigue and either left or right frontal white matter Ch/Cr. Longer disease duration was associated with higher left frontal white matter Ch/Cr. Correlations remained significant when we considered disease duration and left frontal white matter Ch/Cr against total PASAT score and total dyads.
Patients with SLE were impaired on the PASAT. Lower total PASAT score and fewer dyads correlated with higher left frontal microstructural white matter damage, while cognitive fatigue did not. This pattern suggests that early white matter damage interferes with working memory in SLE and provides further insight into the neurobiological basis of mild cognitive dysfunction related to microstructural white matter injury.
Hashimoto encephalopathy (HE) is a distinct form of encephalopathy, which can manifest itself with purely psychiatric symptoms. A 38-year-old female with history of rheumatoid arthritis was treated with psychotropic drugs for a couple of years in psychiatric structures because of the onset of depressive symptoms, psychoticlike manifestations, and impairment of cognitive functions. The electroencephalography (EEG) was characterized by general slowing with high voltage (2 to 3 Hz) delta biphasic and triphasic waves. Once a firm diagnosis of HE was made, corticosteroid treatment resulted in resolution of her psychiatric symptoms, marked EEG improvement, and partial improvement in her cognitive functions. HE should be suspected in young females with history of autoimmune disorders and EEG abnormalities.
Many patients with systemic lupus erythematosus have central nervous system involvement. Routine diagnostic studies may not yield evidence of neuropsychiatric dysfunction and are therefore not useful as objective measures to monitor treatment response. We present a case of a 64-year-old woman whom we diagnosed with systemic lupus erythematosus by the American College of Rheumatology criteria after she reported recent cognitive decline. Neuropsychological assessment showed prominent deficits, and an F-18 fluorodeoxyglucose positron emission tomography scan of the brain showed significant abnormalities. Both the neuropsychiatric and scan abnormalities improved dramatically with immunosuppressive treatment. F-18 fluorodeoxyglucose positron emission tomography shows promise in the diagnosis and treatment monitoring of patients who have lupus with neuropsychiatric involvement.
Frontotemporal dementia (FTD) is an insidious presenile neurodegenerative disorder presenting with personality changes, compulsive behaviors, psychosis, apathetic, aberrant, and elated mood and behavior. No psychopharmacologic strategy has proven to be efficacious in the treatment of FTD yet. This is a case report of FTD in a 53-year-old male engineer whose alcohol abuse, but not other compulsive behaviors, responded to topiramate. Alcohol exerts reinforcing effects on cortico-mesolimbic dopamine pathways through the disinhibition of the inhibitory effects of gamma-amino-butyric acid-A neurons in the ventral tegmental area. Topiramate is a sulfamate-substituted fructopyranose derivative that may antagonize the reinforcing effects associated with the abuse liability of alcohol by modulation of cortico-mesolimbic dopamine function. On the basis of the mechanism of action of topiramate, we discuss the possible specificity of action of topiramate to control abusive drinking, but not to treat other clinical symptoms of FTD.
To examine the impact of malignancy and location of the cerebellar tumor on motor, cognitive, and psychologic outcome.
Although many studies focus on long-term outcome after cerebellar tumor treatment in childhood, the impact of its precise location remains unclear.
Children, aged from 6 to 13 years, with a cerebellar malignant tumor (MT; MT group, n=20) or a cerebellar benign tumor (BT; BT group, n=19) were examined at least 6 months after the end of treatment using the international cooperative ataxia rating scale, the Purdue pegboard for manual skill assessment and the age-adapted Weschler scale. Structural changes in brain anatomy were evaluated and parents and teachers answered 2 independent questionnaires.
Parents and teachers reported high rate of learning and academic difficulties, but without any difference with respect to the type of tumor. However, children with cerebellar MT showed increased cognitive and motor difficulties compared with children with cerebellar BT. Cerebellar signs at clinical examination and manual skill impairment were strongly associated with cognitive difficulties. Both motor and cognitive impairments were found to be associated with extension of the lesion to the dentate nuclei.
Dentate nuclei lesions are major risk factors of motor and cognitive impairments in both cerebellar BT and MT.
Language impairment is a common symptom of Alzheimer disease (AD), and is thought to be related to semantic processing. This study examines the contribution of another process, namely visual perception, on measures of confrontation naming and semantic association abilities in persons with probable AD.
Twenty individuals with probable mild-moderate Alzheimer disease and 20 age-matched controls completed a battery of neuropsychologic measures assessing visual perception, naming, and semantic association ability. Visual discrimination tasks that varied in the degree to which they likely accessed stored structural representations were used to gauge whether structural processing deficits could account for deficits in naming and in semantic association in AD.
Visual discrimination abilities of nameable objects in AD strongly predicted performance on both picture naming and semantic association ability, but lacked the same predictive value for controls. Although impaired, performance on visual discrimination tests of abstract shapes and novel faces showed no significant relationship with picture naming and semantic association. These results provide additional evidence to support that structural processing deficits exist in AD, and may contribute to object recognition and naming deficits.
Our findings suggest that there is a common deficit in discrimination of pictures using nameable objects, picture naming, and semantic association of pictures in AD. Disturbances in structural processing of pictured items may be associated with lexical-semantic impairment in AD, owing to degraded internal storage of structural knowledge.
To examine the contribution of the Addenbrooke's Cognitive Examination (ACE), neuropsychological assessment, and a magnetic resonance imaging (MRI)-based temporal lobe rating scale to the prediction of which patients with questionable dementia will progress to Alzheimer's disease (AD).
Fifty subjects (19 early AD, 31 questionable dementia [QD]) underwent the ACE, a neuropsychological evaluation, and a volumetric MRI. The degree of atrophy of hippocampal, parahippocampal, and other temporal lobe structures was assessed using a validated visual rating scale. Subjects were followed 8 monthly for an average of 19.1 months.
Of the 31 QD subjects, 11 converted to AD within 24 months of follow-up (another 2 developed dementia with Lewy bodies) and 18 were nonconverters. Converters were impaired relative to nonconverters at baseline on measures of episodic and semantic memory (category fluency and naming) and the ACE. Converters also had a greater degree of hippocampal and parahippocampal atrophy. Discriminant analysis demonstrated that the best single test for distinguishing converters was the ACE. In combination, the hippocampal rating and category fluency were also contributory.
Progression to AD in patients with QD is best predicted by neuropsychological measures, particularly those that assess episodic and semantic memory, although simple rating methods based on MRI may have an adjunctive role.
To evaluate whether treatment with acetylcholinesterase inhibitors (AChEIs) exerts a favorable effect on the behavioral dimensions in Alzheimer disease (AD) over time.
Two hundred AD patients entered the study and underwent clinical and neuropsychologic examination. Neuropsychiatry Inventory (NPI) total scores and 4 behavioral factor scores, termed "psychosis," "moods," "apathy," and "frontal" were also evaluated. Of this large sample, 107 completed the 6-month follow-up and 83 were followed through for 1 year. Latent Trajectory Modeling analysis was applied, which allows for the estimation of a developmental trajectory over time for each case in the sample adjusting for confounders. These trajectories can be modeled to better understand individual differences in rates of change of behavioral dimensions and the relationship with AChEIs dose therapy.
The behavioral phenotypes and NPI total scores were differently expressed, the most prevalent being the mood and the less prevalent being frontal endophenotype over time. The development relationship between the baseline and trend levels of behavioral phenotypes, or NPI total scores and the differences of AChEIs, adjusting for disease severity, concurrent drugs, and demographic data did not "travel together" through time, that is, the correlations of individual trajectories could be estimated equal to zeros.
These data confirm that behavioral dimensions are variably represented in AD and change over time. However, AChEIs could not influence the behavioral disturbance pattern, both measured as total behavioral abnormality burden or as behavioral defined clusters.
We explored the constituents of the graphemic buffer in a patient with acquired dysgraphia and tested the hypothesis that the graphemic buffer is composed of 2 dissociable components: letter selection and letter assembly.
Research on dysgraphia has established the graphemic buffer as a component of the spelling mechanism, and the buffer is considered a short-term memory store that is critical for letter production. However, little is known about the components within the buffer.
We devised 2 spelling tasks that rely differentially on letter selection and letter assembly. In the selection task, our patient produced the letters that composed a target word, but she did not have to provide serial position information. In the assembly task, B.H. was given all the letters of a target word and was asked to spell the word by arranging the letters in the proper serial order.
Compared to spelling to dictation, our patient did not benefit from being given letter identity information (ie, assembly task), but her performance improved significantly when position information was available (ie, selection task).
Based on these data, and the comparison of her performance with another dysgraphic patient, we propose that the graphemic buffer engages in both letter selection and letter assembly.
Acquired equivalence is a phenomenon in which prior training to treat 2 stimuli as equivalent increases generalization between them. Previous studies demonstrated that the hippocampal complex might play an important role in acquired equivalence associative learning. In this study, we tested the possibility that acquired equivalence learning is a sensitive marker of mild Alzheimer disease (AD).
In the associative learning test, antecedent stimuli were cartoon faces and consequent stimuli were different colored cartoon fishes. Each cartoon character had some pet fish and the task was to learn these face-fish associations using feedback provided after each decision. In the transfer phase, knowledge about face-fish pairs had to be generalized to new associations.
AD patients exhibited mild impairments in the training phase, whereas they were profoundly impaired on the acquired equivalence test. Associative knowledge could not be transferred to a more flexible retrieval condition.
These results suggest that acquired equivalence learning is specifically impaired in early AD, which may indicate the pathology of the hippocampal complex.
Individuals with autism often fail to develop useful speech. If they have not done so by age 5, the prognosis for future development has been thought to be poor. However, some cases of later development of speech have been reported. To quantify and document the nature of later speech development and the factors that might be important for prognosis, we reviewed the extant literature. We searched both manually and electronically, examining all literature with at least an English-language abstract, through March 2008. The search identified a total of 167 individuals with autism who reportedly acquired speech at age 5 or older. Most of the cases of reported late speech development occurred in the younger age groups; no case older than 13 was reported. Behavioral modification was the most frequently reported training program used, although there was a wide range of interventions reported to be associated with late speech development. Given the underreporting of such cases in the literature, and the likelihood that more intensive and more focused training might be more successful, the prognosis for late development of speech in such individuals may now be better than was historically thought to be the case.
To investigate neuropsychiatric manifestations in patients at various stages of Alzheimer's disease (AD).
Several earlier studies reported high prevalence of neuropsychiatric symptoms in patients with AD; to date, no such study has been conducted in Turkey.
We evaluated 217 patients with AD from 18 referral centers across Turkey using a web-based dementia data registry. The Mini Mental State Examination and the Neuropsychiatric Inventory (NPI) were used to evaluate the global cognitive function, and assessment of neuropsychiatric symptoms, respectively. We classified the patients into mild, moderate, and severe stages on the basis of their Mini Mental State Examination scores. We assessed group differences and correlations between the degree of AD severity and NPI values.
The highest NPI scores were seen in patients with severe AD. The mean composite scores for apathy, anxiety, and depression were the highest. The prevalence of any behavioral symptom was 86%. There was no difference in the behavioral domain between the groups or between the referral centers. Moderate correlation was found between the severity of AD and the total NPI score. The caregivers' NPI distress scores varied among referral centers.
The prevalence of behavioral disturbance in AD is high and similar to earlier studies, yet regional differences are seen in caregivers' reactions to behavioral symptoms.
: We sought to compare age-related performance on the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) across the adult lifespan in an asymptomatic, presumably normal, sample.
: The MMSE is the most commonly used brief cognitive screening test; however, the MoCA may be better at detecting early cognitive dysfunction.
: We gave the MMSE and MoCA to 254 community-dwelling participants ranging in age from 20 to 89, stratified by decade, and we compared their scores using the Wilcoxon signed rank test.
: For the total sample, the MMSE and MoCA differed significantly in total scores as well as in visuospatial, language, and memory domains (for all of these scores, P<0.001). Mean MMSE scores declined only modestly across the decades; mean MoCA scores declined more dramatically. There were no consistent domain differences between the MMSE and MoCA during the third and fourth decades; however, significant differences in memory (P<0.05) and language (P<0.001) emerged in the fifth through ninth decades.
: We conclude that the MoCA may be a better detector of age-related decrements in cognitive performance than the MMSE, as shown in this community-dwelling adult population.
We introduce a novel test that allows pictorial, nonverbal assessment of action understanding.
Focusing on action goals and the sequential nature of actions, the "Tomato and Tuna Test" tests whether exposure to the accomplished goal of an action is sufficient to infer the preceding action. This aspect has rarely been addressed in conventional paradigms.
We used the Tomato and Tuna Test in conjunction with another task, the Kissing and Dancing Test, to detect action understanding deficits in 11 patients (mean age 72±6 years) with chronic brain lesions±aphasia. We compared their performance to an age- and education-matched control group and to 15 young controls (mean age 24±3 years). To investigate the influence of language deficits on test performance, we compared the scores of our patients with and without aphasia.
Our patients were less accurate than the matched controls on the Tomato and Tuna Test, though not slower. The Kissing and Dancing Test did not differentiate between patients and matched controls. Young controls performed better than patients on both tests.
We found no performance differences between our aphasic and nonaphasic patients, confirming our assumption that both tests measure action understanding without requiring intact language abilities. We recommend the "Tomato and Tuna Test" as a new nonverbal measure of action understanding that can reveal subtle deficits.
To present the first near infrared spectroscopy (NIRS) study of a patient with resistant catatonic schizophrenia during residual episodes of catatonia-related symptoms.
Functional imaging studies generally point to a decreased cortical activation in catatonic patients, with the notable exception of increased orbitofrontal/medial prefrontal activity elicited by negative stimuli.
Cortical activity of the left anterior prefrontal area was recorded with a Techen 4 x 4 NIRS apparatus. Four episodes of staring/mutism were recorded and averaged. Compared with normal activity, these episodes were characterized by increased cortical activation.
Within its methodologic limitations, the present observation suggests that increased anterior prefrontal activation in catatonic patients is not specific to negative stimuli. Known functions of the anterior prefrontal cortex such as self monitoring, reallocation of attention, or conflict resolution might underlie these findings. These also attest to the potential of NIRS for functional imaging of vulnerable subjects.
To use clinical specimens to better understand the neuropathogenesis of prospective memory (ProM) functioning in persons with HIV-1 infection.
Emergent evidence suggests that HIV-1 is associated with impaired ProM, but the underlying neuropathophysiology of this deficit is not known.
Thirty-five nondemented subjects with HIV-1 infection completed measures of both ProM (ie, memory for future intentions) and retrospective memory (RM; ie, memory for past episodes). A panel of biomarkers reflecting several possible neuropathogenic mechanisms of HIV was measured in plasma and cerebrospinal fluid, including HIV-1 RNA, total tau, monocyte chemoattractant protein-1 (MCP-1), soluble receptor for tumor necrosis factor type II, and fibroblast growth factor 1.
After controlling for antiretroviral therapy and CD4 lymphocyte count, higher levels of MCP-1 in plasma, and soluble receptor for tumor necrosis factor type II and tau in cerebrospinal fluid were associated with ProM, but not RM. Markers of astrocytosis, growth factor depletion, and HIV-1 replication did not predict either ProM or RM.
ProM impairment in HIV-1 may be dissociable from RM, perhaps reflecting specific neuropathogenic mechanisms of macrophage activation and axonal injury.
To evaluate the relationship between the autonomic nervous system basal state and performance in decision-making tasks.
The link between performance in decision-making tasks and acute changes in autonomic parameters during their execution has been extensively investigated. However, there is lacking evidence regarding the relationship between decision making and basal autonomic state.
Resting autonomic nervous system activity in 18 healthy individuals was assessed by means of heart rate variability (HRV) analysis before conducting 3 different decision-making tasks: an ambiguous one, the Iowa Gambling Task; a test that assesses risk-taking behavior, the Game of Dice Task; and a test that assesses reversal learning behavior, the Reversal Learning Task. The tasks were administered in a random manner.
There was a direct correlation between the Iowa Gambling Task net score and the resting low frequency HRV (r = 0.73; P < 0.001), which is strongly influenced by sympathetic activity. No correlations were found between HRV and the Game of Dice Task net score or the Reversal Learning Task last error trial.
The results are compatible with the idea that a higher basal activation of autonomic nervous system is beneficial for subsequent decision-making process.
The objective of the study was to determine whether patients with schizophrenia and their unaffected first-degree relatives have abnormal autonomic nervous system (ANS) responses to social cognition tasks.
Social cognition impairments are significant in schizophrenia. ANS activity has been shown to be abnormal in schizophrenia patients, and some of the abnormalities seem to be shared by patients' unaffected relatives.
Heart rate variability (HRV) was measured at rest and during social cognition tasks, in patients with schizophrenia, their nonpsychotic first-degree relatives, and matched healthy controls (n=19 in each group).
Social cognition tasks induced a shortening of the RR interval in unaffected relatives, but not in patients. Social cognition tasks generated decreases in high-frequency (indicating cardiac vagal activity) and low-frequency (reflecting predominantly sympathetic activity) HRV in patients. In relatives, the decrease occurred in the high-frequency component only. Low-frequency HRV was higher in patients during a theory of mind task than a control task. These changes were not observed in the controls.
Social cognitive tasks induce a pattern of peripheral autonomic activity different from that seen in generic arousal responses, and this pattern is abnormal in schizophrenia patients. Autonomic abnormalities in unaffected first-degree relatives seem restricted to the parasympathetic division of the ANS.
To determine whether everyday life activities are affected by general cognitive impairment or tool using disabilities in Alzheimer disease (AD) and vascular dementia (VaD).
Thirty AD the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) and 30 VaD the state of California Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC) patients and 10 normal controls (NC) were studied. Everyday activities in the community were assessed with the Social Activities Questionnaire (SAQ), and tool uses were evaluated with the single-tool and the multiple-tool sequence tasks.
The SAQ scores of the AD and VaD groups were significantly lower than that of the NC group. For the single tool tasks, the AD and VaD groups exhibited lower scores than the NC group. The sequence score of the VaD group was lower than that of the AD group. The multiple regression analysis disclosed that the SAQ of the AD group was explained by the Mini-Mental State Examination and sequence scores. However, that of the VaD group was mainly explained by the sequence scores.
Disturbances in everyday life activities of AD are associated with general cognitive impairment and sequence disabilities. By contrast, those of VaD may be based only on sequence disabilities.
To study emotional behaviors in an acute stroke population.
Alterations in emotional behavior after stroke have been recently recognized, but little attention has been paid to these changes in the very acute phase of stroke.
Adult patients presenting with acute stroke were prospectively recruited and studied. We validated the Emotional Behavior Index (EBI), a 38-item scale designed to evaluate behavioral aspects of sadness, aggressiveness, disinhibition, adaptation, passivity, indifference, and denial. Clinical, historical, and imaging (computed tomography/magnetic resonance imaging) data were obtained on each subject through our Stroke Registry. Statistical analysis was performed with both univariate and multivariate tests.
Of the 254 patients, 40% showed sadness, 49% passivity, 17% aggressiveness, 53% indifference, 76% disinhibition, 18% lack of adaptation, and 44% denial reactions. Several significant correlations were identified. Sadness was correlated with a personal history of alcohol abuse (r = P < 0.037), female gender (r = P < 0.028), and hemorrhagic nature of the stroke (r = P < 0.063). Aggressiveness was correlated with a personal history of depression (r = P < 0.046) and hemorrhage (r = P < 0.06). Denial was correlated with male gender (r = P < 0.035) and hemorrhagic lesions (r = P < 0.05). Emotional behavior did not correlate with either neurologic impairment or lesion localization, but there was an association between hemorrhage and aggressive behavior (P < 0.001), lack of adaptation (r = P < 0.015), indifference (r = P < 0.018), and denial (r = P < 0.045).
Systematic observations of acute emotional behaviors after stroke suggest that emotional alterations are independent of mood and physical status and should be considered as a separate consequence of stroke.
We report a case of pathology-proven acute disseminated encephalomyelitis (ADEM) in which the patient's symptoms were solely cognitive. Although cognitive dysfunction is a well-recognized symptom in adults with multiple sclerosis, cognitive assessment of adults with ADEM has rarely been reported. A 35-year-old woman was referred to our center for evaluation of cognitive disturbance and demyelinating lesions seen on brain magnetic resonance imaging (MRI). We performed a neurologic examination, full neuropsychological assessment, brain MRI, blood and cerebrospinal fluid analyses, visual evoked potentials, and brain biopsy. The patient's Mini-Mental State Examination score was 26/30. Cognitive assessment revealed multiple severe dysfunctions, mainly in executive and attention tasks. She scored below the normal range on the Digit Span Forward and Backward Test and the Trail Making Test Part B. The Frontal Assessment Battery showed deficits in mental flexibility, motor programming, and inhibitory control. She also scored in the impaired range on tests of verbal fluency and memory. The brain MRI and biopsy confirmed a diagnosis of ADEM. This case report points to the limitations of relying on clinical presentation, neuroimaging, and current controversial diagnostic criteria in diagnosing ADEM in adults, and highlights the essential role of pathologic evaluation.
Many patients develop cognitive impairment after an acute stroke. It is not clear whether blood pressure variability is a prognostic factor for cognitive impairment. We aimed to determine the association between blood pressure variability on hospital admission and cognitive outcome in patients with acute lacunar infarction.
We performed a retrospective analysis on 22 men and 14 women (mean age, 61.8 years) who had completed a cognitive evaluation 3 months after onset of an acute lacunar infarction. The patients had no previous functional disability or dementia, stenosis in major cerebral arteries, cardiac embolic sources, or infarct in strategic territories for cognition. We used standard deviation and coefficient of variance as parameters of blood pressure variability, and each cognitive function test z score as an outcome parameter. We performed linear regression analysis to assess the relationship between blood pressure variability and cognition, adjusted for vascular risk factors, severity of neurologic deficits, and mean blood pressure.
High variability of both systolic and diastolic blood pressure was significantly associated with low z scores on the Controlled Oral Word Association Test and the Digit Symbol Coding test (P<0.01). High variability of diastolic blood pressure was significantly associated with low z scores on the Korean Mini-Mental State Examination and Seoul Verbal Learning Test delayed recall (P<0.01).
Highly variable blood pressure on admission for acute lacunar infarction may predict poor cognitive outcomes, especially frontal lobe dysfunction.
To perform a pilot study to examine a range of cognitive flexibility tasks early in cocaine withdrawal.
Previous neuropsychological investigations of cocaine withdrawal have conflicted regarding whether impaired cognitive flexibility occurs. However, most studies have examined patients later in withdrawal. Anxiety and yohimbine-induced panic are greatest early in withdrawal, and both anxiety and increased noradrenergic tone can impair cognitive flexibility.
Twelve patients acutely withdrawing from cocaine were compared with gender-, age-, and estimated premorbid intelligence-matched control subjects on tests of cognitive flexibility as well as verbal fluency, verbal memory, spatial memory, and attention.
As predicted, impairments were found on the cognitive flexibility tasks. Impairments also were present in verbal fluency and verbal memory but not spatial memory or attention.
We propose that the cognitive flexibility impairment may relate to the increased noradrenergic activation recently described in cocaine withdrawal. Impairments on verbal tasks may also relate to an impaired flexibility in the search of semantic networks. Further research will explore the effects of pharmacologic manipulation of the noradrenergic system on cognition in acute withdrawal. Recently, propranolol has been shown to benefit patients in cocaine withdrawal. Further research will explore whether impaired cognitive flexibility related to altered noradrenergic tone could serve as a mechanism for this treatment response.
Little is known about cognitive differences between patients showing neglect and those without neglect in their acute stroke stage. The aim of this study was to investigate how the patients with neglect (N+) differ from those without neglect (N-) in general cognitive function assessed by the Mini-Mental State Examination (MMSE).
Patients consisted of 98 consecutive patients with acute right hemisphere stroke. The patients underwent neglect test battery followed by MMSE in the same day.
The frequency of cognitive deficits in N+ group was higher than that of N- group (74.1% vs. 35.0%). A regression analysis, after controlling for lesion volume, age, and education, showed that neglect was a significant predictor of low MMSE score. Among MMSE subdomains, the severity of neglect was related to poor performances on episodic memory (orientation and 3-word recall), working memory/calculation (serial 7s), and constructional praxis (interlocking pentagons).
These results suggest that hemispatial neglect is associated with several forms of cognitive deficits in patients with acute right hemisphere stroke.
To describe a case of acute nonherpetic limbic encephalitis (LE) with negative testing for antibodies directed against onconeuronal and cell membrane antigens, including voltage-gated potassium channels and N-methyl-D-aspartate receptor, that showed a dramatic response to immune therapy.
A 30-year-old woman manifested generalized seizures, altered consciousness, and memory impairment shortly after a prodromal viral illness. Few days later the patient developed a drug-resistant epileptic status.
Electroencephalograph showed bitemporal slowing and paroxysmal slow wave bursts. Brain magnetic resonance imaging showed bilateral swelling in the medial temporal lobes. Cerebrospinal fluid analysis ruled out viral etiologies. A diagnostic search for cancer, including serum testing for known onconeuronal antibodies proved negative. Screening for cell membrane antigen antibodies, including voltage-gated potassium channels and N-methyl-D-aspartate receptor, was also negative. Suspecting an autoimmune etiology, we started an immunomodulatory treatment with intravenous immunoglobulin followed by a short course of oral prednisone, obtaining a full clinical recovery.
Our report confirms previous observations of "seronegative" autoimmune LE, suggesting the presence of other, still unknown central nervous system antigens representing a target of a postinfectious, autoimmune response in these patients. Moreover, it emphasizes the importance of early recognition and treatment of acute autoimmune LE, to reduce the risk of intensive care unit-related complications and the occurrence of permanent cognitive or behavioral defects.
In view of the negative impact of anxiety on working memory, we induced anxiety in 26 patients with acute stroke and 33 healthy controls, and studied how the anxiety affected their emotional reactivity and how the reactivity affected their verbal and visuospatial working memory. We compared the overall findings with those in 1 of our patients (C.B.) who had presented with an abnormally high level of state anxiety.
We gave verbal and visuospatial 1-back tasks under both neutral and anxiogenic conditions, and we compared participants' working memory scores, self-reported levels of state anxiety, and electrodermal activity.
When comparing performance in the neutral condition, the control and patient groups exhibited disrupted verbal working memory, which was associated with greater electrodermal activity and higher state anxiety during the anxiogenic condition. Although patient C.B. also had heightened electrodermal activity during the anxiogenic condition, she experienced a significant reduction in her state anxiety. Her verbal working memory was better during the anxiogenic than the neutral condition.
Because of the phonological (subvocal speech) nature of verbal working memory, a higher level of anxious apprehension could explain the increase in state anxiety and the corresponding disruption of verbal working memory in our patient and control groups during the anxiogenic condition. C.B.'s lower state anxiety and selective improvement in verbal working memory during the anxiogenic condition suggest that she felt less anxious apprehension.
Hemi-neglect is a disorder characterized by a disregard of contralesional stimuli. Some neglect patients also show an "exaggerated attention" for the ipsilesional field, reflected in perseverative responses, such as repetitive fixations in the ipsilesional field, ipsilesional revisitings on standard cancellation, or exaggerations in drawings on the ipsilesional side.
It is still unclear whether neglect and perseveration are due to a single underlying mechanism. In the present study, we will examine the effect of 4-day-in-a-row prism adaptation on neglect and perseveration severity in a patient with severe perseverations. Additionally, we will examine whether the position of omissions and perseverations on the Star Cancellation will change during the intervention.
Our patient showed a decrease in neglect severity and an increase in perseveration severity, suggesting that perseveration and neglect are dissociated phenomena. Interestingly, 4-day-in-a-row prism adaptation gradually moved the predominant position of perseverative responses from right to left as neglect decreased with treatment.
Perseverative responses do not necessarily occur in the ipsilesional sector of space as is generally assumed. Instead, the position of the revisits may be determined by the severity of the neglect, and may shift when the focus of attention moves more contralesionally with recovery.
Research indicates that individuals with attention deficit disorder (ADD)/attention deficit hyperactivity disorder (ADHD) may exhibit left-right asymmetric spatial attention, with deficient processing of stimuli in the left visual hemispace. However, there is controversy as to when this phenomenon can be observed.
People with ADD/ADHD do not have obvious spatial bias when performing everyday tasks. Visual cancellation tasks have demonstrated behavioral asymmetry in ADD/ADHD, but results have not been consistent across studies. Children and older adults with ADD or ADHD have been assessed, but previous studies of college students with ADD/ADHD are not available.
We tested 24 students with ADD or ADHD and 24 control students on a verbal and nonverbal cancellation task.
The ADD/ADHD group made significantly more left-sided omission errors than controls on a letter cancellation task. This group difference was not observed for a shape cancellation task, however.
These results support possible left visual inattention in college students with ADD/ADHD. Studies of functional correlates of these attentional phenomena are needed.
To provide normative data for healthy middle-aged and elderly Brazilians' performance on the Addenbrooke Cognitive Examination-Revised (ACE-R) and to investigate the effects of age, sex, and schooling on test performance.
The ACE-R is a brief cognitive battery that assesses various aspects of cognition. Its 5 subdomains (Attention and Orientation, Memory, Verbal Fluency, Language, and Visuospatial Abilities) are commonly impaired in Alzheimer disease or frontotemporal dementia.
We evaluated 144 cognitively healthy volunteers (50% men, 50% women) aged 50 to 93 years, with 4 to 24 years of schooling. We divided the participants into 4 age groups, each of which was then stratified into 3 groups according to years of education. We assessed all participants with the ACE-R, the Mattis Dementia Rating Scale, and the Cornell Scale for Depression in Dementia.
Years of education affected all ACE-R subscores. Age influenced the Verbal Fluency subscore (P<0.001) and the ACE-R total score (P<0.05). Sex affected the Attention and Orientation (P=0.037) and Mini-Mental State Examination subscores (P=0.048), but not the ACE-R total score (P>0.05).
The performance of healthy middle-aged and elderly individuals on the ACE-R battery is strongly influenced by education and, to a lesser extent, by age. These findings are of special relevance in countries with populations that have marked heterogeneity in educational levels.
To investigate the accuracy of the Brazilian version of the Addenbrooke Cognitive Examination-revised (ACE-R) in the diagnosis of mild Alzheimer disease (AD).
The ACE-R is an accurate and brief cognitive battery for the detection of mild dementia, especially for the discrimination between AD and frontotemporal dementia.
The battery was administered to 31 patients with mild AD and 62 age-matched and education-matched cognitively healthy controls. Both groups were selected using the Dementia Rating Scale and were submitted to the ACE-R. Depression was ruled out in both groups by the Cornell Scale for Depression in Dementia. The performance of patients and controls in the ACE-R was compared and receiver operator characteristic curve analysis was undertaken to ascertain the accuracy of the instrument for the diagnosis of mild AD.
The mean scores at the ACE-R were 63.10+/-10.22 points for patients with AD and 83.63+/-7.90 points for controls. The cut-off score <78 yielded high diagnostic accuracy (receiver operator characteristic area under the curve=0.947), with 100% sensitivity, 82.26% specificity, 73.8% positive predictive value, and 100% negative predictive value.
The Brazilian version of the ACE-R displayed high diagnostic accuracy for the identification of mild AD in the studied sample.
Gambling is a form of nonsubstance addiction classified as an impulse control disorder. Pathologic gamblers are considered healthy with respect to their cognitive status. Lesions of the frontolimbic systems, mostly of the right hemisphere, are associated with addictive behavior. Because gamblers are not regarded as "brain-lesioned" and gambling is nontoxic, gambling is a model to test whether addicted "healthy" people are relatively impaired in frontolimbic neuropsychological functions.
Twenty-one nonsubstance dependent gamblers and nineteen healthy subjects underwent a behavioral neurologic interview centered on incidence, origin, and symptoms of possible brain damage, a neuropsychological examination, and an electroencephalogram.
Seventeen gamblers (81%) had a positive medical history for brain damage (mainly traumatic head injury, pre- or perinatal complications). The gamblers, compared with the controls, were significantly more impaired in concentration, memory, and executive functions, and evidenced a higher prevalence of non-right-handedness (43%) and, non-left-hemisphere language dominance (52%). Electroencephalogram (EEG) revealed dysfunctional activity in 65% of the gamblers, compared with 26% of controls.
This study shows that the "healthy" gamblers are indeed brain-damaged. Compared with a matched control population, pathologic gamblers evidenced more brain injuries, more fronto-temporo-limbic neuropsychological dysfunctions and more EEG abnormalities. The authors thus conjecture that addictive gambling may be a consequence of brain damage, especially of the frontolimbic systems, a finding that may well have medicolegal consequences.
There are several forms of agraphia, including: aphasic agraphia, where patients have impairments in writing the correct words or correctly spelling words; apraxic agraphia, where patients are impaired in making the movements needed to write letters; and spatial agraphia, where patients might fail to write letters on one side of a word or write on one side of a page. In several of these agraphic disorders, patients can make perseverative errors, and perseverative errors can even be seen in patients who do not have aphasia or apraxic agraphia. Patients who make continuous perseverative errors repeatedly writes the same letter (fruuuit) or word, and patients with recurrent perseverations change their letters, but then incorrectly use letter or word that was previously used (fruiut). We report a patient who demonstrated a different form of graphic perseveration.
A 61-year-old man with a right parietal lobe lesion and left-sided neglect developed an inability to write. When attempting to write, he repeatedly wrote the same letter that he first wrote, and wrote these in the same spatial position as the first letter. When spelling, reading aloud, and using a keyboard to write he did not perseverate letters or words. When performing the cancellation test and drawings, he also perseverated.
This patient demonstrated a novel form of perseverative behavior. Although the mechanism of this spatially adherent graphemic perseveration remains to be elucidated fully we provide evidence that this patient's right parietal lesion caused a visuomotor disengagement disorder.
The noradrenergic system modulates cognitive flexibility for insight-based problem solving in studies using beta-adrenergic antagonists, which block noradrenergic neurotransmission postsynaptically. However, it is not known whether alpha2-adrenergic agonists, that decrease noradrenergic neurotransmission by presynaptic inhibition, have the same effect.
Therefore, we wished to test whether alpha2-adrenergic agonists would have a similar effect on cognitive flexibility.
Eighteen normal adults were tested on cognitive flexibility, problem solving, verbal and spatial memory tasks after receiving clonidine (0.1 mg), an alpha2-agonist, placebo, or ephedrine (25 mg), a noradrenergic stimulant.
Three-way analysis of variance revealed no significant drug effect on cognitive flexibility or problem solving. There was also no significant effect of clonidine on memory.
Therefore, alpha2-agonists do not influence cognitive flexibility in the same manner as beta-antagonists. Better performance on memory with clonidine might be expected based on primate studies demonstrating benefits in working memory using clonidine. This benefit was not observed for the commonly used clinical memory tasks in our study. This may have implications for why clonidine has not demonstrated efficacy for cognitive disorders such as Alzheimer disease, despite its known benefit for working memory in animal models.
To describe a case of a rare adult-onset craniopharyngioma presenting as rapidly progressive catatonia that was reversed after surgical resection of the tumor.
Profoundly depressed states of awareness classified as either catatonia or akinetic mutism have been reported in patients with hypothalamic neoplasms, but reports of improvement in consciousness level after surgical resection are rare and limited to very large tumors.
Medical, neurologic, and psychiatric histories, physical examination findings, laboratory workup results, pathologic and imaging studies, and response to surgical treatment were documented.
The patient showed progressive improvement in mental status and overall neurologic function after surgical treatment.
The search for an etiology of a profound catatonic state should include the probability of a suprasellar/hypothalamic lesion, which in this case was owing to the rare finding of an imaging-documented adult-onset craniopharyngioma.
The literature on neuroplasticity lacks a direct comparison of chronic neuropsychological and social outcomes following brain damage acquired in childhood versus adulthood, when lesions are matched across adults and children for size and location.
We paired adults and children with similar unilateral stroke lesions and then compared chronic neuropsychological and social outcomes. Quantitative comparisons were conducted, as well as qualitative analyses of each subject pair, focusing on specific domains of cognitive impairment and changes in social functioning.
We found that learning and memory impairments were most common in both children and adults. Left hemisphere-lesioned children were normal on speech/language ratings, whereas their adult counterparts were borderline impaired. Impairments in social functioning were highly associated with hemispheric side of damage in adults, but not in children: Specifically, adults with right hemisphere lesions developed social defects much more frequently than adults with left hemisphere lesions, whereas this asymmetry was not evident in the children. Most importantly, though, was the overarching finding of a high degree of similarity between chronic neuropsychological and social function outcomes in adults and children with similarly located brain lesions due to unilateral stroke.
On balance, the findings suggest that lesion location and size are prepotent factors determining neuropsychological and social recovery from stroke.
To learn if acetylcholinesterase inhibitors alter verbal recall by improving semantic encoding in a double-blind randomized placebo-controlled trial.
Cholinergic supplementation has been shown to improve delayed recall in adults with Alzheimer disease. With functional magnetic resonance imaging, elderly adults, when compared with younger participants, have reduced cortical activation with semantic processing. There have been no studies investigating the effects of cholinergic supplementation on semantic encoding in healthy elderly adults.
Twenty elderly participants (mean age 71.5, SD+/-5.2) were recruited. All underwent memory testing before and after receiving donepezil (5 mg, n=11 or 10 mg, n=1) or placebo (n=8) for 6 weeks. Memory was tested using a Levels of Processing task, where a series of words are presented serially. Subjects were either asked to count consonants in a word (superficially process) or decide if the word was "pleasant" or "unpleasant" (semantically process).
After 6 weeks of donepezil or placebo treatment, immediate and delayed recall of superficially and semantically processed words was compared with baseline performance. Immediate and delayed recall of superficially processed words did not show significant changes in either treatment group. With semantic processing, both immediate and delayed recall performance improved in the donepezil group.
Our results suggest that when using semantic encoding, older normal subjects may be aided by anticholinesterase treatment. However, this treatment does not improve recall of superficially encoded words.
The present study examined the relationship between multiple indices of blood pressure (BP) and cognitive function (as measured by the Dementia Rating Scale).
Cardiovascular disease (CVD) is associated with cognitive dysfunction and cerebrovascular pathology in the elderly and is a known risk factor for stroke and Alzheimer disease. Yet, the mechanisms for the effects of CVD on cognitive function are not well understood.
Participants were 97 nondemented older adults with CVD who underwent neuropsychologic assessment, and a 2-hour cardiovascular laboratory protocol.
After controlling for age and years of education, results of hierarchical linear regression analyses indicate a significant positive relationship between a function of BP variability (SD of systolic BP divided by the average diastolic BP) and cognitive function (R change=0.042, F (1, 85)=5.434, P<0.05). No relationship emerged between any other BP index and cognitive function.
Contrary to expectations, greater BP variability was associated with better, not poorer, cognitive test performance. These findings suggest that the relationship between BP and cognitive function is more complicated than originally conceptualized and requires further investigation.
To characterize cognition in patients with moderate to severe heart failure and examine the association between 2 measures of systemic perfusion (ie, ejection fraction and cardiac index) and cognition.
Decreased systemic perfusion has been implicated as an etiologic factor in the development of cognitive deficits in cardiovascular disease.
Thirty-one patients with moderate to severe heart failure and 31 patients with cardiovascular disease and no heart failure completed a medical history interview and neuropsychologic assessment. Participants with heart failure additionally underwent an echocardiogram to assess cardiac function.
Patients with heart failure performed significantly worse than the cardiovascular disease-no heart failure group on several measures of executive functioning and psychomotor speed. Among the heart failure group, lower ejection fraction was associated with weaker global cognition, performance on several, but not all, measures of executive functioning, and was marginally associated with delayed memory. Decreased cardiac index was associated with poorer immediate memory and weakly associated with global cognition.
Findings suggest that depressed systemic perfusion is associated with cognitive deficits among patients with heart failure. Research including measures of cardiac function, cerebral perfusion, and cognition will be necessary to clarify the causal nature of the suggested mechanism.
To compare temporal order memory in older adults with and without human immunodeficiency virus (HIV) infection.
The frontal and temporal lobes play a key role in temporal order memory for items in a sequence. HIV-associated episodic memory deficits correlate with damage to neocortical interneurons in the fronto-striato-thalamo-cortical pathway and with atypical activation of the medial temporal lobes. Therefore, temporal order memory may be sensitive to neuropathological changes in individuals with HIV.
In this study, 50 HIV-seropositive individuals aged ≥ 50 years and 50 seronegative controls performed a computerized visuospatial temporal order memory task. During the sample phase of each trial, participants were shown circles presented 1 at a time in a random sequence at the end of each of the 8 arms of a radial maze. During the choice phase, they were shown the maze with a circle at the ends of 2 of the arms and asked which circle had appeared earlier than the other in the original sequence.
Performance in both groups improved as a function of greater temporal separation between circle presentations. However, the HIV group had significantly worse memory impairment across all temporal separations, and the impairment was independently associated with clinical deficits in executive function and delayed retrospective memory.
Our results extend prior findings that HIV is associated with deficits in strategic aspects of memory encoding and retrieval. The neural mechanisms warrant further research, as do potential impacts on everyday function, eg, adherence to antiretroviral drug regimens.
The primary objective of this study was to meta-analytically investigate whether total brain volume (TBV) and total intracranial volume (TICV) differ between adult participants with posttraumatic stress disorder (PTSD) and controls.
TICV reaches maximum growth by early adolescence and provides an estimate of premorbid brain size. Little work has directly examined TBV in PTSD participants, although limited evidence suggests that deficits in brain volume may occur.
Using electronic databases, we identified articles containing TBV and TICV data for adult PTSD participants. Data were extracted and effect sizes were calculated.
We identified 8 studies with TBV data (105 PTSD participants and 122 trauma-unexposed controls) and 2 studies with TICV data (18 PTSD participants and 25 trauma-unexposed controls). TBV was significantly smaller in PTSD participants compared with trauma-unexposed controls. In contrast, TICV did not differ between these groups. There were no significant differences in TBV and TICV between PTSD and trauma-exposed controls.
TBV is significantly smaller in adult PTSD participants compared with trauma-unexposed controls. TICV did not differ significantly between these groups, suggesting that a deficit in TBV occurred at some point after the attainment of maximum brain volume in the PTSD group.
: In the absence of stroke or transient ischemic attack, patients with advanced carotid stenosis or occlusion (ICAs/o) are considered asymptomatic, yet they are prone to mostly subtle cognitive impairment.
: The Mini-Mental State Examination (MMSE) often fails to detect mild cognitive impairment. The Montreal Cognitive Assessment (MoCA) is more sensitive in recognizing such changes.
: Scores on the MoCA and MMSE were compared in 70 asymptomatic patients with ICAs/o and 70 controls matched for demographic variables and vascular risk factors.
: MMSE scores fell mostly within the normal range in both patients and controls. Differences were significant for total MoCA scores (P<0.001). Patients with ICAs/o performed worse on visuospatial and executive function (P=0.018), abstraction (P<0.001), and delayed recall (P<0.001). Lower MoCA scores were associated with diabetes (odds ratio=6.41; 95% confidence interval, 1.277-32.220; P=0.024) and older age (odds ratio=0.86; 95% confidence interval, 0.780-0.956; P=0.004). Patients with diabetes performed worse on delayed recall (P<0.001), and patients with hypertension were worse on the MoCA naming subtest (P=0.04).
: The MoCA successfully identified reduced cognitive status in patients with ICAs/o. The MoCA subtest scores revealed a pattern of cognitive impairment similar to that documented in other studies using more extensive neuropsychological tests. MoCA could be used as part of the clinical evaluation of patients with ICAs/o.
The aim of this study was to evaluate changes in cognitive functioning and emotive state in 3 inpatients with advanced Parkinson disease (PD) treated with extradural motor cortex stimulation (EMCS), an experimental neurosurgical procedure.
Studies on the neuropsychologic assessment of patients with PD after EMCS are in process. The procedure has been applied for some years as an experimental method for treating PD.
A battery of neuropsychologic tests and emotive assessment scales were administered to 3 inpatients with PD 2 days before the intervention and then again after 1 year to evaluate changes in cognitive functioning and emotive state.
At 1-year postintervention, cognitive functions and depressive symptoms were steady; 2 patients showed a mild improvement in quality of life.
In this patient group, EMCS, an experimental neurosurgical treatment, had a positive effect on motor symptoms. Neuropsychologic assessment after a 1-year follow-up period showed that cognitive functions had not changed with respect to baseline characteristics.
Decision under ambiguity and decision under risk are fundamental in every-day life.
We investigated these 2 types of decision in traumatic brain injury (TBI) patients through the Iowa Gambling Task (IGT), the Probability-Associated Gambling (PAG) task, and a counsel version of the PAG task. Although in the IGT rules for gain and losses are implicit and probability information is missing, in the PAG task and the counsel task rules are explicit and probabilities are well-defined.
In the IGT, TBI patients selected more disadvantageously than healthy controls and failed to develop an advantageous strategy over time. Patients also made less advantageous choices than controls in the PAG task and the counsel task. Compared with controls, TBI patients gambled more frequently with low probabilities and less frequently with high probabilities. Overall, participants decided more advantageously in the counsel task, which does not provide feedback, than in the PAG task. Importantly, our results indicate that TBI patients' performance on all decision tasks correlated with executive functions.
Our study shows that TBI patients have difficulties in decision under risk and decision under ambiguity. Difficulties may be attributed to deficient learning from feedback and to reduced risk estimation, but not to impulsive risk taking behavior.