Publications (31)151.66 Total impact
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Article: Quantified electroencephalographic changes in Parkinson's disease with and without dementia
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ABSTRACT: We examined the presence of quantified electroencephalographic (qEEG) differences between Parkinson's disease (PD) patients with and without dementia, and a group of age-comparable normal controls. While there were no significant differences in relative power in any of the qEEG bands between PD patients without dementia and normal controls, PD patients showed a significantly greater reactivity in the alpha band. On the other hand, PD patients with dementia showed significantly less alpha and more theta relative power than both the normal control and the PD without dementia groups. When PD patients with dementia were compared with a group of patients with Alzheimer's disease (AD) and a similar severity of dementia, no significant between-group differences were found in any of the qEEG bands. In conclusion, while our study demonstrated no significant qEEG differences between non-demented PD patients and normal controls, PD patients with dementia showed qEEG changes similar to those observed in patients with AD.European Journal of Neurology 01/2011; 1(2):147 - 152. · 3.69 Impact Factor -
Article: Bilateral pallidotomy for treatment of Parkinson's disease induced corticobulbar syndrome and psychic akinesia avoidable by globus pallidus lesion combined with contralateral stimulation.
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ABSTRACT: Posteroventral pallidotomy (PVP) has proved to be an effective method for the treatment of Parkinson's disease. However, data on bilateral procedures are still limited. To assess the effects of bilateral globus pallidus (GPi) lesion and to compare it with a combination of unilateral GPi lesion plus contralateral GPi stimulation (PVP+PVS), an open blind randomised trial was designed. A prospective series of patients with severe Parkinson's disease refractory to medical treatment, and severe drug induced dyskinesias, were randomised either to simultaneous bilateral PVP or simultaneous PVP+PVS. All patients were assessed with the core assessment programme for intracerebral transplantation (CAPIT), and a comprehensive neuropsychological and neuropsychiatric battery both before surgery and 3 months later. The severe adverse effects found in the first three patients subjected to bilateral PVP led to discontinuation of the protocol. All three patients developed depression and apathy. Speech, salivation, and swallowing, as well as freezing, walking, and falling, dramatically worsened. By contrast, all three patients undergoing PVP+PVS had a significant motor improvement. Bilateral simultaneous lesions within the GPi may produce severe motor and psychiatric complications. On the other hand, a combination of PVP+ PVS significantly improves parkinsonian symptoms not associated with the side effects elicited by bilateral lesions.Journal of Neurology Neurosurgery & Psychiatry 12/2001; 71(5):611-4. · 4.76 Impact Factor -
Article: Neuropsychological effects of pallidotomy in patients with Parkinson's disease.
Journal of Neurology Neurosurgery & Psychiatry 11/2001; 71(4):563-4. · 4.76 Impact Factor -
Article: Disruption of spatial organization and interjoint coordination in Parkinson's disease, progressive supranuclear palsy, and multiple system atrophy.
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ABSTRACT: Patients with basal ganglia diseases may exhibit ideomotor apraxia. To define the nature of the impairment of the action production system, we studied a repetitive gesture of slicing bread by three-dimensional computergraphic analysis in eight nondemented patients with Parkinson's disease in the "on" state, five with progressive supranuclear palsy and four with multiple system atrophy. Two patients with Parkinson's disease and two with progressive supranuclear palsy showed ideomotor apraxia for transitive movements on standard testing. A Selspott II system was used for kinematic analysis of wrist trajectories and angular motions of the shoulder and elbow joints. Patients with Parkinson's disease, progressive supranuclear palsy, and even some with multiple system atrophy exhibited kinematic deficits in the spatial precision of movement and velocity-curvature relationships; in addition, they failed to maintain proper angle/angle relationships and to apportion their relative joint amplitudes normally. Spatial disruption of wrist trajectories was more severe in patients with ideomotor apraxia. We posit that the basal ganglia are part of the parallel parieto-frontal circuits devoted to sensorimotor integration for object-oriented behavior. The severity and characteristics of spatial abnormalities of a transitive movement would therefore depend on the location and distribution of the pathologic process within these circuits.Movement Disorders 08/2000; 15(4):627-40. · 4.51 Impact Factor -
Article: Unilateral radiofrequency lesion versus electrostimulation of posteroventral pallidum: a prospective randomized comparison.
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ABSTRACT: Microelectrode-guided posteroventral pallidotomy (PVP) has shown to be an effective method in the treatment of a group of patients with advanced Parkinson's disease. A nonlesioning approach by means of deep brain electrodes connected to a programmable neuropacemaker has also been used to inhibit the internal segment of globus pallidus (posteroventral stimulation [PVS]) reporting comparable clinical efficacy to the one obtained with the ablative method. Nevertheless, no controlled studies have been performed to compare the efficacy of both procedures. A prospective series of 13 patients with a clinical indication for globus pallidus surgery was randomized either to a pallidotomy or stimulator implantation, and comparisons on motor and neuropsychologic measurements were made on a 3-month follow-up basis. Primary measurements of efficacy showed a comparable effect on Unified Parkinson's Disease Rating Scale and activities of daily living score after both procedures. Secondary measurements of efficacy showed that although both techniques improve hand tapping score and dyskinesia score, the bilateral improvement in the former was greater after PVS whereas the latter improved more significantly after PVP. No significant changes in neuropsychologic parameters were observed after either PVP or PVS. Side effects and surgery complications occurred in six of 13 patients (three after PVP and three after PVS): they were mild, transient, and unrelated to optic tract injury. In conclusion, the short-time effect and safety of both procedures is comparable.Movement Disorders 02/1999; 14(1):50-6. · 4.51 Impact Factor -
Article: Movement quality of repetitive self-paced single joint rapid arm movements on Parkinson's disease: acute effect of 1-dopa.
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ABSTRACT: Most studies on single-joint ballistic movements in PD have reported smaller differences between ON and OFF states than those exhibited when PD patients are compared with normal controls. We developed a mathematical model (quality of movement coefficient, QMC), which represents a combination of the diverse kinematic variables applicable to repetitive ballistic movements and depicting the differences between normal subjects and PD patients as well as disclosing changes induced by 1-dopa. Seven patients were evaluated in ON and OFF states. An optoelectronic system (SELSPOT II) was used to digitize movement trajectories. Patients were instructed to repetitively flex and extend the forearms maximizing speed during 20 s. Seven normal controls were also evaluated. Significant differences were found in the QMC between ON and OFF states (ANOVA p < 0.0 1) and between patients and normal controls (ANOVA p < 0.04). Moreover, QMC significantly correlated with UPDRS motor score in both ON and OFF states [R2 F(1,5) = 12.06; p < 0.01]. In conclusion, we found that QMC seems to be a sensitive indicator of Parkinsonian disabilities as well as of 1-dopa effect.Parkinsonism & Related Disorders 06/1998; 4(1):31-7. · 3.80 Impact Factor -
Article: Sleep benefit in Parkinson's disease.
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ABSTRACT: Sleep benefit (SB) In Parkinson's disease (PD) is not well characterized. To determine SB frequency, as well as to characterize and correlate it with other disease variables, we evaluated prospectively a consecutive series of 312 PD patients by means of a structured questionnaire: 55% reported having SB and 35% reported that awakening was their best time of the day. Because of SB, 21% of the entire population were able to skip or delay medication. The mean duration of the phenomenon was 85.4 +/- 67 min. Patients with SB were significantly older (p < 0.0002), had disease longer (p < 0.05), and were often men (chi 2 = 3.5, df 1, p = 0.05). Patients with SB took sleep medication with similar frequency as those without SB. There were no differences in hours of sleep or sleep latency. Sleep problems such as nightmares or somnambulism, but not the number of sleep awakenings, were similar in both groups. In conclusion, SB is a frequent phenomenon, especially in men, elderly patients, and patients with longer disease duration. SB enables the morning L-dopa dose to be postponed in approximately 50% of patients.Movement Disorders 07/1997; 12(4):506-8. · 4.51 Impact Factor -
Article: Apraxia in Parkinson's disease, progressive supranuclear palsy, multiple system atrophy and neuroleptic-induced parkinsonism.
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ABSTRACT: We studied 45 non-demented patients with Parkinson's disease (PD), 12 with progressive supranuclear palsy (PSP), 10 with multiple system atrophy (MSA) and 12 with neuroleptic-induced parkinsonism (NIP) for the presence of apraxia. Our aim was to determine whether a standard comprehensive assessment of different praxic functions would demonstrate specific types of errors not attributable to bradykinesia, rigidity, tremor or any other abnormal elementary motor deficit. PD patients on chronic levodopa treatment were examined in the 'on' and 'off' (treatment) states. Based on apraxia assessment scores, bilateral ideomotor apraxia for transitive movements was found in eight (75%) and 12 (27%) of PSP and PD patients, respectively. Ideomotor apraxia was mainly characterized by spatial errors (i.e., external and internal configuration, body-part-as-object and trajectory). Four PSP but no PD patients exhibited ideomotor apraxia for intransitive movements. PSP as well as PD patients with ideomotor apraxia also had difficulties in imitating hand and finger postures, but none of them failed on pantomime comprehension and pantomime recognition/discrimination. Some PSP patients exhibited, in addition, a limbkinetic type of apraxia and a minority of them displayed deficits on tasks involving multiple steps. Neither MSA nor NIP patients showed any disturbance of praxic functions. There were no differences in age, disease duration, Mini Mental State Examination (MMSE), Unified Parkinson's disease Rating Scale and Hoehn-Yahr scores between apraxic and non-apraxic PD patients, and ideomotor apraxia scores were similar in the 'on' and 'off' states. A correlation was found between ideomotor apraxia scores in PD patients and deficits in frontal lobe-related neuropsychological tasks such as the Tower of Hanoi, verbal fluency and the Trail Making Test. Furthermore, PD patients with apraxia showed higher Hamilton depression scores than non-apraxic PD patients. In PSP patients, ideomotor apraxia scores correlated significantly with cognitive deficit as measured with MMSE. The presence or absence of cortical involvement, and its severity and distribution might determine the presence and type of apraxia in PD and PSP. Apraxia in these conditions would therefore reflect combined cortico-striatal dysfunction.Brain 02/1997; 120 ( Pt 1):75-90. · 9.46 Impact Factor -
Article: Drug-induced parkinsonism in schizophrenic patients: motor response and psychiatric changes after acute challenge with L-Dopa and apomorphine.
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ABSTRACT: Acute single-dose response of drug-induced parkinsonism (DIP) to L-Dopa and apomorphine challenge was evaluated in a double-blind crossover study in 12 schizophrenic patients. There were two noteworthy negative findings. First, neither L-Dopa nor apomorphine produced significant improvements in DIP and second, no changes (neither improvement nor worsening) were found in patients' psychiatric status. Findings suggest that, for a stimulation dose reaching almost 90% of the responsive dose for idiopathic Parkinson's disease, no significant changes may reasonably be expected in the parkinsonism of schizophrenic patients treated with neuroleptic drugs.Clinical Neuropharmacology 11/1996; 19(5):439-43. · 2.17 Impact Factor -
Article: Quantified electroencephalographic correlates of relative frontal or parietal hypoperfusion in dementia.
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ABSTRACT: The authors examined the presence of specific quantified electroencephalographic (qEEG) changes in dementia patients with relatively lower frontal or parietal blood perfusion as demonstrated by SPECT. Over all brain regions, patients with relatively lower parietal perfusion showed significantly higher theta relative power than demented patients with relatively lower frontal perfusion or normal control subjects. Dementia patients with relatively lower frontal perfusion showed no differences from age-comparable normal control subjects in qEEG variables. These findings 1) suggest that usefulness of qEEG for the diagnosis of dementia is restricted to a subgroup of patients with the typical SPECT pattern of parietal blood hypoperfusion and 2) demonstrate that the qEEG changes typical of dementia are not related to perfusion deficits in frontal brain areas.Journal of Neuropsychiatry 02/1996; 8(1):26-32. · 2.51 Impact Factor -
Article: A randomized, double-blind, placebo-controlled study of bromocriptine in nonfluent aphasia.
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ABSTRACT: We carried out a double-blind and placebo-controlled study of the efficacy of bromocriptine in the treatment of nonfluent aphasia. Seven patients received bromocriptine (up to 60 mg/d) and an identical placebo in a randomized order. End points were the number of content words, content units, and pauses > 3 seconds during the description of a figure; verbal naming; and verbal fluency. There were no significant benefits of bromocriptine over placebo in any of the variables examined.Neurology 01/1996; 45(12):2272-4. · 8.31 Impact Factor -
Article: Quantified electroencephalographic changes in depressed patients with and without dementia.
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ABSTRACT: We carried out quantified electroencephalograms (qEEG) in 17 patients with probable Alzheimer's disease (AD), who also met the DSM-III-R criteria for either dysthymia or major depression, and 18 AD patients with comparable intellectual impairment but no depression, 13 patients with depression but no AD, and 10 age-matched normal controls. There was a significant effect for depression in alpha relative power: depressed patients (with or without AD) showed a significantly lower alpha relative power in the right posterior region as compared to nondepressed patients; however, this change was observed over the right hemisphere in depressed non-AD patients, and in left, medial, and right posterior regions in depressed-AD patients. Depressed patients without AD showed a significant global decrease in delta power, whereas depressed patients with AD showed significant increments in delta power in posterior brain areas. In conclusion, AD patients with depression showed qEEG changes that were significantly different from qEEG changes in depressed non-AD patients.Biological Psychiatry 12/1995; 38(10):677-83. · 8.28 Impact Factor -
Article: Quantified electroencephalographic correlates of neuropsychological deficits in Alzheimer's disease.
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ABSTRACT: The authors examined relationships between quantified EEG (qEEG) variables and neuropsychological performance in 54 consecutive patients with probable Alzheimer's disease (AD). Patients were studied with qEEG and a neuropsychological battery that assessed memory, attention, verbal functions, set-shifting abilities, and procedural learning. More severe memory, attention, and verbal deficits were significantly correlated with lower alpha relative power, and increased theta relative power was significantly correlated with poor set-shifting abilities. No qEEG variables were significantly correlated with the procedural learning task. These correlations between deficits in specific cognitive domains and qEEG bands suggest that qEEG may have an important role in the investigation of the cognitive deficits in AD.Journal of Neuropsychiatry 02/1995; 7(1):61-7. · 2.51 Impact Factor -
Article: Extrapyramidalism in Alzheimer's disease: prevalence, psychiatric, and neuropsychological correlates.
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ABSTRACT: The prevalence and clinical correlates of extrapyramidal signs in a consecutive series of 78 patients with Alzheimer's disease attending a neurology clinic, and 20 age comparable normal controls, were examined. Based on the unified Parkinson's disease rating scale (UPDRS) findings, 18 patients (23%) met criteria for parkinsonism, 44 (56%) had isolated extrapyramidal signs, and 16 (21%) had no extrapyramidal signs. Whereas the control group showed a similar prevalence of isolated extrapyramidal signs (57%), none of them showed parkinsonism. No significant differences were found for age, sex, duration of illness, and severity of dementia among the three Alzheimer's disease groups. Patients with Alzheimer's disease-parkinsonism, however, showed a significantly higher frequency of major depression and dysthymia and significantly higher Hamilton depression scores than patients with isolated or no extrapyramidal signs. Patients with Alzheimer's disease-parkinsonism also showed significantly more deficits on frontal lobe related tasks such as the Wisconsin card sorting test, trail making test, and verbal fluency, as well as on tests of constructional praxis and abstract reasoning than patients with Alzheimer's disease but no extrapyramidal signs. In conclusion, the study showed a specific association between Alzheimer's disease and parkinsonism, as well as significant relations between parkinsonism, deficits in executive functions, and depression among patients with Alzheimer's disease.Journal of Neurology Neurosurgery & Psychiatry 01/1995; 57(12):1503-9. · 4.76 Impact Factor -
Article: The nature of apraxia in corticobasal degeneration.
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ABSTRACT: Although apraxia is one of the most frequent signs in corticobasal degeneration, the phenomenology of this disorder has not been formally examined. Hence 10 patients with corticobasal degeneration were studied with a standardised evaluation for different types of apraxia. To minimise the confounding effects of the primary motor disorder, apraxia was assessed in the least affected limb. Whereas none of the patients showed buccofacial apraxia, seven showed deficits on tests of ideomotor apraxia and movement imitation, four on tests of sequential arm movements (all of whom had ideomotor apraxia), and three on tests of ideational apraxia (all of whom had ideomotor apraxia). Ideomotor apraxia significantly correlated with deficit in both the mini mental state examination and in a task sensitive to frontal lobe dysfunction (picture arrangement). Two of the three patients with ideomotor apraxia and ideational apraxia showed severe cognitive impairments. The alien limb behaviour was present only in patients with ideomotor apraxia. In conclusion, ideomotor apraxia is the most frequent type of apraxia in corticobasal degeneration, and may be due to dysfunction of the supplementary motor area. There is a subgroup of patients with corticobasal degeneration who have a severe apraxia (ideomotor and ideational apraxia), which correlates with global cognitive impairment, and may result from additional parietal or diffuse cortical damage.Journal of Neurology Neurosurgery & Psychiatry 05/1994; 57(4):455-9. · 4.76 Impact Factor -
Article: Bromocriptine-induced dystonia in patients with aphasia and hemiparesis.
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ABSTRACT: Five of seven patients with chronic nonfluent aphasia and hemiparesis due to a focal ischemic infarction developed painful hemidystonia during treatment with a high dose of bromocriptine. All seven patients had cortical damage, but four also had basal ganglia and one thalamic involvement. While lesion location did not differ between dystonic and nondystonic patients, the dystonic patients had more weakness than those without dystonia.Neurology 12/1993; 43(11):2319-22. · 8.31 Impact Factor -
Article: Quantified electroencephalographic correlates of depression in Alzheimer's disease.
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ABSTRACT: While depression is one of the most frequent psychiatric problems among patients with probable Alzheimer's disease (AD), its mechanism is not well known. We performed quantified EEGs in a consecutive series of seven patients with mild dementia and depression, six patients with mild dementia and no depression, eight patients with moderate dementia and depression, and eight patients with moderate dementia and no depression. Regardless of the severity of dementia, depressed patients had a significantly higher percent theta in posterior brain areas. Moreover, depressed patients with mild AD showed a similar theta frequency as non-depressed patients with moderate AD. These findings suggest that the presence of depression may contribute to the qEEG changes of AD.Biological Psychiatry 10/1993; 34(6):386-91. · 8.28 Impact Factor -
Article: Paroxysmal alien hand syndrome.
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ABSTRACT: Four patients are described who presented with a paroxysmal form of the alien hand syndrome. Two patients with damage to one frontomedial cortex had brief episodes of abnormal motor behaviour of the contralateral arm that featured groping, grasping, and apparently purposeful but perseverative movements, which both patients interpreted as alien or foreign. The other two patients, with posterior parietal damage, reported a paroxysmal feeling of unawareness of the location of the contralateral arm, lack of recognition of the arm as their own, purposeless movements, and personification of the arm. These cases represent a new form of the alien hand syndrome manifested by brief, paroxysmal episodes, which may be due to ictal mechanisms.Journal of Neurology Neurosurgery & Psychiatry 08/1993; 56(7):788-92. · 4.76 Impact Factor -
Article: Anterior callosal haemorrhage. A partial interhemispheric disconnection syndrome.
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ABSTRACT: The interhemispheric disconnection syndrome secondary to a callosal haemorrhage is exceedingly uncommon. In the present study, 3 patients with haemorrhages restricted to the corpus callosum are presented. All 3 developed a partial anterior interhemispheric disconnection syndrome: unilateral tactile anomia, unilateral agraphia, unilateral apraxia, difficulty in copying drawings, dyscalculia as well as abnormalities of somaesthetic transfer and the 'alien hand' sign. The study of these cases allowed a close examination of the association between deficits in the transfer of specific neuropsychological information and the precise topography of callosal damage. Variability in the lateralization of cognitive functions, and possible mechanisms underlying the production of callosal haemorrhages after the rupture of saccular aneurysms are also discussed.Brain 09/1989; 112 ( Pt 4):1019-37. · 9.46 Impact Factor -
Article: Asymbolia for pain: a sensory-limbic disconnection syndrome.
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ABSTRACT: We describe the behavioral and neuroanatomical features of asymbolia for pain occurring in 6 patients following unilateral hemispheric damage secondary to ischemic lesions in 5 and traumatic hematoma in 1. In the absence of primary sensory deficits, these 6 patients showed a lack of withdrawal and absent or inadequate emotional responses to painful stimuli applied over the entire body, as well as to threatening gestures. Five patients also failed to react to verbal menaces. Patients appeared unconcerned about the defect and seemed unable to learn appropriate escape or protective responses. Common associated abnormalities were rapidly resolving hemiparesis, cortical-type sensory loss, unilateral neglect, and body-schema disorders. Neuroradiological examination disclosed left hemispheric lesions in 4 patients and right hemispheric involvement in 2. Although lesion extension differed, the insular cortex was invariably damaged in all 6 patients. These findings suggest that insular damage may play a critical role in the development of the syndrome by interrupting connections between sensory cortices and the limbic system.Annals of Neurology 08/1988; 24(1):41-9. · 11.09 Impact Factor
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1988–2000
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FLENI
Buenos Aires, Buenos Aires F.D., Argentina
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