[Show abstract][Hide abstract] ABSTRACT: Background
Although the decrease in striatal dopamine transporter (DAT) density has been described in North American, European, and Asian Parkinson’s disease (PD) patients, studies on this issue are required in the rest of the world. This study examined the diagnostic utility of DAT imaging in Brazilian PD patients.
Twenty PD patients (13 males, 7 females, median age: 62 years, median age at disease onset: 56 years, median disease duration: 5 years, and median UPDRS-III score: 29) and 9 age- and sex-matched healthy subjects underwent single-photon emission computerized tomography (SPECT) using 99mTc-TRODAT-1.
PD patients showed a significant decrease in the striatum, caudate nucleus, and putamen DAT densities compared with data from healthy subjects. Striatal 99mTc-TRODAT-1 bindings had the highest diagnostic accuracy compared to those estimates from caudate nucleus and putamen. For the diagnosis of PD, a striatal 99mTc-TRODAT-1 binding cut-off value of 0.90 was associated with a sensitivity of 100% and a specificity of 89%. There was no significant difference between striatal 99mTc-TRODAT-1 binding values provided by different readers, contrary to 99mTc-TRODAT-1 binding estimates in the caudate nucleus.
Striatal DAT imaging using 99mTc-TRODAT-1 can be considered a marker for differentiating PD patients from healthy individuals, with a good interobserver reproducibility.
Full-text · Article · Aug 2014 · Medical science monitor: international medical journal of experimental and clinical research
[Show abstract][Hide abstract] ABSTRACT: Objective:
To test the hypothesis that severity of cognitive impairment modifies the association between depression and Parkinson's disease (PD).
One-phase population-based door-to-door surveys. This is a secondary analysis of 1,451 people aged 65 years and older with cognitive impairment living in defined catchment areas. Depression was estimated according to ICD-10, self-reported PD, disability according to WHODAS-II and cognitive status according to the CSI-D.
The mean age of the sample was 79.3 years old and most (69%) were women. Of the total sample, 16.1% had depression and it was significantly higher among participants with PD. There was an increase on the ORs of the association between depression and PD with decreased scores in the cognitive test (Adjusted OR from 0.98 to 8.04).
The association between depression and PD increases with the severity of the cognitive impairment.
Full-text · Article · Jun 2014 · Arquivos de Neuro-Psiquiatria
[Show abstract][Hide abstract] ABSTRACT: Approximately 10% of patients with a presumed diagnosis of Parkinson’s disease (PD) remain misdiagnosed despite recent advances in neuroimaging. The current study addresses the use of transcranial sonography and single-photon emission computed tomography (SPECT) using 99mTc-TRODAT-1 to evaluate the echogenicity of the substantia nigra (SN) and the density of striatal presynaptic dopamine transporters, respectively, in a sample of 20 PD patients (13 males and 7 females) and 9 healthy subjects. The median age of the PD patients was 62 years. The median age at disease onset was 56 years, and the median disease duration was 5 years. The SN echogenic area was larger in PD patients than healthy subjects. The cut-off value of 0.22 cm2 for the SN echogenic area was associated with 100% sensitivity and 78% specificity for the diagnosis of PD. Striatal and putaminal 99mTc-TRODAT-1 binding was lower in PD patients than healthy subjects. The cut-off value of 0.90 for the striatal 99mTc-TRODAT-1 binding was associated with 100% sensitivity and an 89% specificity for the diagnosis of PD, and the cut-off value of 0.76 for putaminal 99mTc-TRODAT-1 binding was associated with an 85% sensitivity and an 89% specificity. The size of the SN echogenic area did not correlate with the degree of striatal 99mTc-TRODAT-1 binding in PD patients. In conclusion, both SN hyperechogenicity and decreased striatal or putaminal 99mTc-TRODAT-1 binding constitute surrogate markers for differentiating PD patients from healthy individuals with a slightly higher diagnostic specificity of 99mTc-TRODAT-1 SPECT.
No preview · Article · May 2014 · Parkinsonism & Related Disorders
[Show abstract][Hide abstract] ABSTRACT: Pituitary apoplexy is a rare threatening condition, still often misdiagnosed. In line with this the treating physician should be aware of pituitary apoplexy as a potential diagnoses whenever a patient seeks care with acute-onset headache associated with visual loss, ophthalmoparesis and altered mental status. In line with this there are several known predisposing factors that may lead to pituitary apoplexy as well, and eventually their early identification will be a clue to diagnosis or will help tailor patient management. Herein, our aim is to focus on these factors associated with pituitary apoplexy grouped into six major categories: associated medical conditions, surgery, head trauma and endocrinological testings.
[Show abstract][Hide abstract] ABSTRACT: The human brain can be evaluated in vivo using modern molecular imaging techniques, made possible by the availability of different single-photon emission computed tomography or positron emission tomography radioligands, some of which are now commercially available. Dopamine transporters and receptors are of particular interest in this context, not only because of the several radiotracers available to study different dopamine sites but also due to the importance of Parkinson's disease (PD) as the second most common neurodegenerative disease worldwide, and as a prototype condition of dopaminergic dysfunction. Here, the authors discuss the current knowledge on tracers for the assessment of presynaptic and postsynaptic dopamine function, along with other tracers of interest, such as serotonin binding ligands. The clinical relevance of these studies includes assistance in diagnosis, assessment of disease severity and progression including that of individuals at an increased risk of developing PD, and insights into the pathogenesis of PD motor and nonmotor symptoms.
[Show abstract][Hide abstract] ABSTRACT: To compare the dopaminergic neuronal imaging features of different subtypes of genetic Parkinson's Disease.
A retrospective study of genetic Parkinson's diseases cases in which DaTSCAN (123I-FP-CIT) had been performed. Specific non-displaceable binding was calculated for bilateral caudate and putamen for each case. The right:left asymmetry index and striatal asymmetry index was calculated.
Scans were available from 37 cases of monogenetic Parkinson's disease (7 glucocerebrosidase (GBA) mutations, 8 alpha-synuclein, 3 LRRK2, 7 PINK1, 12 Parkin). The asymmetry of radioligand uptake for Parkinson's disease with GBA or LRRK2 mutations was greater than that for Parkinson's disease with alpha synuclein, PINK1 or Parkin mutations.
The asymmetry of radioligand uptake in Parkinsons disease associated with GBA or LRRK2 mutations suggests that interactions with additional genetic or environmental factors may be associated with dopaminergic neuronal loss.
[Show abstract][Hide abstract] ABSTRACT: Background:
Several studies have demonstrated increased substantia nigra (SN) echogenicity in Parkinson's disease (PD) and Machado-Joseph disease (MJD). Pathological substrate of PD is characterized by dopaminergic nigrostriatal cell loss, also found in MJD. Also, SN hyperechogenicity might be associated with nigrostriatal dysfunction in PD, when comparing dopamine transporter binding with SN echogenicity. The present study aimed to correlate the SN echogenic size and striatal dopamine transporter density in MJD patients.
We performed TCS in 30 subjects and SPECT with [(99m)Tc]-TRODAT-1 in 18 subjects with MJD. Fifteen healthy subjects matched for age and gender formed a control group. TCS and [(99m)Tc]-TRODAT-1 SPECT findings from both MJD patients and control subjects were compared.
There were no differences regarding age (p = 0.358) or gender (p = 0.566) between groups (MJD versus control group). Mean DAT binding potentials and SN echogenicity were significantly different between groups. There was a significant negative correlation with regard to the SN echogenic size and the ipsilateral striatal TRODAT-1 uptake: the higher the SN echogenicity, the lower the DAT uptake in the ipsilateral cerebral hemisphere.
Increase in SN echogenic size likely correlates with presynaptic dopaminergic nigrostriatal dysfunction in MJD, suggesting a concurrent in vivo pathophysiological mechanism.
No preview · Article · May 2013 · Parkinsonism & Related Disorders
[Show abstract][Hide abstract] ABSTRACT: Objectives:
Sleep disorders, especially restless legs syndrome (RLS) and rapid eye movement sleep behavior disorder (RBD), are common in spinocerebellar ataxia type 3 or Machado-Joseph disease (MJD), and a possible underlying dopaminergic dysfunction is implicated. This study assessed the relationship between sleep disorders in MJD and dopamine transporter (DAT) densities.
Patients and methods:
Twenty-two patients with MJD and twenty healthy subjects were enrolled in this study. MJD patients underwent clinical sleep evaluation and polysomnography. SPECT with [(99m)Tc]-TRODAT-1, was performed in all subjects.
DAT densities were significantly reduced in MJD group when compared to controls. No significant correlation was found between DAT densities and RLS or RBD in MJD.
Our study failed to demonstrate a clear correlation between sleep disorders and DAT densities in MJD patients, hence suggesting that extrastriatal and non-presynaptic dopamine pathways could be implicated in MJD-related sleep disorders.
No preview · Article · Nov 2012 · Journal of the neurological sciences
[Show abstract][Hide abstract] ABSTRACT: Diagnosing oncogenic osteomalacia is still a challenge. The disorder is characterized by osteomalacia caused by renal phosphate wasting and low serum concentration of 1,25-dihydroxyvitamin D3 occurring in the presence of a tumor that produces high levels of fibroblast growth factor 23. However, it is possible that the disease is much more misdiagnosed than rare. We present the case of a 42-year-old man with a long-term history of undiagnosed progressive muscle weakness. His laboratory results mainly showed low serum phosphate. Surgical removal of a nasal hemangiopericytoma that had been diagnosed five years earlier, brought him to a symptom-free condition. Even though knowing the underlying etiology would explain his osteomalacia, the patient sought medical help from countless physicians for five consecutive years, and only after adequate treatment a rewarding outcome was achieved. Arq Bras Endocrinol Metab. 2012;56(8):570-3.
Full-text · Article · Nov 2012 · Arquivos brasileiros de endocrinologia e metabologia
[Show abstract][Hide abstract] ABSTRACT: It was to analyze clinical aspects of patients with blepharospasm, including outcomes of botulinum toxin treatment. Additionally, clinical characteristics of isolated blepharospasm were compared to those of blepharospasm plus other movement disorders.
Clinical data recorded during 17 years were reviewed. The variables included age, gender, age of onset, past medical history, head trauma, smoking history, family history of dystonia, severity, duration of botulinum toxin relief and adverse effects.
A total of 125 patients were included and 75.2% were female. The mean age of onset was 54.3 years; 89.6% of the individuals started with contractions in eye region, and 39.2% of them spread to lower face or neck. Isolated blepharospasm group was compared with blepharospasm-plus group for demographic and clinical features, and therapeutic outcomes, without significant differences. Botulinum toxin treatment improved the severity of contractions (p=0.01) with low rate of side effects (14%).
Both groups - isolated blepharospasm and blepharospasm-plus - shared similar results concerning epidemiology, clinical features and therapeutic response to botulinum toxin.
Full-text · Article · Sep 2012 · Arquivos de neuro-psiquiatria
[Show abstract][Hide abstract] ABSTRACT: The clinical diagnosis of Parkinson's disease (PD) is susceptible to misdiagnosis, especially in the earlier stages of the disease. Recently, in vivo imaging techniques assessing the presynaptic dopamine transporter (DAT) have emerged as a useful tool in PD diagnosis, improving its accuracy.
It was to illustrate the clinical usefulness of a brain single-photon emission computed tomography (SPECT) DAT ligand, and highlight relevant aspects of scans without evidence of dopaminergic deficit (SWEDDs) in this context.
We described four representative patients with clinically unclear parkinsonian syndromes who underwent [99mTc]-TRODAT-1 SPECT and reviewed the clinical implications.
DAT-SPECT is an important, cost-effective, technique for the differential diagnosis of parkinsonian syndromes. Additionally, SWEDD cases present clinical and paraclinical peculiarities that may retrospectively identify them as essential/dystonic tremor. The lack of histopathological data limits further conclusions.
Full-text · Article · Sep 2012 · Arquivos de neuro-psiquiatria
[Show abstract][Hide abstract] ABSTRACT: To determine the clinical correlates of the restless legs syndrome (RLS) in a Brazilian sleep disorders center.
We retrospectively studied 118 patients with RLS from January, 2004, to December, 2010. The analyzed variables were: age at disease onset, gender, race, years of school instruction, primary and secondary RLS, and treatment options.
Among the studied patients, 83.9% were women with a female/male sex ratio of 5:1. Mean age of the patients at symptom onset ± standard deviation was 41.7±17.9 years-old. The primary RLS was found in 85% of patients. The other 15% remainders consisted of secondary forms, and they were associated with neuropathy, iron deficiency anemia, end-stage renal disease, or Parkinson's disease. Drug therapy for RLS was introduced in 67% of patients.
Most patients presented primary RLS with an early disease onset. Further epidemiological studies are welcomed to provide better information on secondary RLS in Brazil.
Preview · Article · Jul 2012 · Arquivos de neuro-psiquiatria
[Show abstract][Hide abstract] ABSTRACT: Some evidence suggests a hyperdopaminergic state in posttraumatic stress disorder (PTSD). The 9-repetition allele (9R) located in the 3' untranslated region of the dopamine transporter (DAT) gene (SLC6A3) is more frequent among PTSD patients. In vivo molecular imaging studies have shown that healthy 9R carriers have increased striatal DAT binding. However, no prior study evaluated in vivo striatal DAT density in PTSD.
The objective of this study was to evaluate in vivo striatal DAT density in PTSD.
Twenty-one PTSD subjects and 21 control subjects, who were traumatized but asymptomatic, closely matched comparison subjects evaluated with the Clinician-Administered PTSD Scale underwent a single-photon emission computed tomography scan with [(99m)TC]-TRODAT-1. DAT binding potential (DAT-BP) was calculated using the striatum as the region of the interest and the occipital cortex as a reference region.
PTSD patients had greater bilateral striatal DAT-BP (mean ± SD; left, 1.80 ± 0.42; right, 1.78 ± 0.40) than traumatized control subjects (left, 1.62 ± 0.32; right, 1.61 ± 0.31; p = 0.039 for the left striatum and p = 0.032 for the right striatum).
These results provide the first in vivo evidence for increased DAT density in PTSD. Increases in DAT density may reflect higher dopamine turnover in PTSD, which could contribute to the perpetuation and potentiation of exaggerated fear responses to a given event associated with the traumatic experience. Situations that resemble the traumatic event turn to be interpreted as highly salient (driving attention, arousal, and motivation) in detriment of other daily situations.
Full-text · Article · Jun 2012 · Psychopharmacology
[Show abstract][Hide abstract] ABSTRACT: To identify the effect of levodopa in language areas in Parkinson's disease patients.
We evaluated 50 patients with mild to moderate Parkinson's disease, age and gender paired to 47 healthy volunteers. We selected two homogeneous groups of 18 patients taking levodopa and 7 no levodopa patients. The functional magnetic resonance imaging verbal fluency task, with low and high cognitive demands, was performed at a 3T magnetic resonance imaging equipment. Data was analyzed with XBAM software for group maps and ANOVA comparison.
Patients without levodopa had more activation than the ones with levodopa in the medial frontal and in the left frontal and parieto-occipital areas. The striatal activation in patients taking levodopa had similar result of the activation detected in the healthy volunteer group. Parieto-occipital areas were less activated in the levodopa group than in the no levodopa one.
Parkinson's disease patients without levodopa replacement, during a verbal fluency effort, had more diffuse and intense cerebral activation in left hemisphere, mainly in the frontal and parieto-occipital areas. The striatal activation in verbal fluency of patients with levodopa intake was more similar to the activation found in healthy volunteers. These initial evidences suggested a role of levodopa inhibiting activation in parieto-occipital compensating areas.
Full-text · Article · Jun 2012 · Einstein (SÃ£o Paulo
[Show abstract][Hide abstract] ABSTRACT: Hyperechogenicity of the substantia nigra is a frequent observation on transcranial sonography in Parkinson's disease and Machado-Joseph disease patients. Additionally, restless legs syndrome is a sleep disorder that is also frequently found in both diseases. Autopsy studies have demonstrated increased SN iron content in hyperechogenic substantia nigra. Iron storage is also known to be involved in restless legs syndrome. We formally compared echogenicity of the substantia nigra with restless legs syndrome in Parkinson's disease and Machado-Joseph disease patients.
Transcranial brain sonography was performed in a sample of Parkinson's disease and Machado-Joseph disease patients, and findings then correlated with the presence and severity of restless legs syndrome.
There was a continuum of substantia nigra echogenicity among groups (Parkinson's disease versus Machado-Joseph disease versus controls) and sub-groups (Parkinson's disease with and without restless legs syndrome versus Machado-Joseph disease with and without restless legs syndrome) as well as a statistically significant negative correlation between restless legs syndrome severity and substantia nigra echogenicity (p<0.001).
These preliminary observations demonstrate that the severity of RLS may be influenced by nigral iron load reflected by substantia nigra echogenicity in different neurodegenerative movement disorders.
No preview · Article · May 2012 · Journal of the neurological sciences
[Show abstract][Hide abstract] ABSTRACT: Cognitive and olfactory impairments have been demonstrated in patients with Machado-Joseph disease (MJD), and a possible relationship with dopaminergic dysfunction is implicated. However, there is still controversy regarding the pattern of striatal dopaminergic dysfunction in patients with MJD. In this study, we investigated whether these patients had different dopamine transporter (DAT) densities as compared to healthy subjects, and correlated these data with cognitive performance and sense of smell. Twenty-two MJD patients and 20 control subjects were enrolled. The neuropsychological assessment comprised the spatial span, symbol search, picture completion, stroop color word test, trail making test and phonemic verbal fluency test. The 16-item Sniffin' Sticks was used to evaluate odor identification. DAT imaging was performed using the SPECT radioligand [(99m)Tc]-TRODAT-1, alongside with Magnetic Resonance imaging. Patients with MJD showed significantly lower DAT density in the caudate (1.34 ± 0.27 versus 2.02 ± 0.50, p < 0.001), posterior putamen (0.81 ± 0.32 versus 1.32 ± 0.34, p < 0.001) and anterior putamen (1.10 ± 0.31 versus 1.85 ± 0.45, p < 0.001) compared with healthy controls. The putamen/caudate ratio was also significantly lower in patients compared with controls (0.73 ± 0.038 versus 0.85 ± 0.032, p = 0.027). Even though we had only two patients with parkinsonism, we detected striatal dopaminergic deficits in those patients. No significant correlations were detected between DAT density and cognitive performance or Sniffin' Sticks scores. The data suggests that striatal dopamine deficit is not involved in cognitive or sense of smell deficits. This finding raises the possibility of extra-striatal dopamine and other neurotransmitter system involvement or of cerebellum neurodegeneration exerting a direct influence on cognitive and sensorial information processing in MJD.
No preview · Article · May 2012 · Parkinsonism & Related Disorders
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: Misdiagnosis in Parkinson's disease (PD) can reach 25%. Recently, single-photon emission computer tomography (SPECT), using dopamine transporter (DAT) radioligands, has become useful to help diagnose clinically unclear cases of Parkinsonism (CUCP). OBJECTIVES: Study 1 reported the rationale of molecular imaging in CUCP. Study 2 evaluated the role of DAT neuroimaging in CUCP. Study 3 studied a sub-group of CUCP with psychogenic Parkinsonism. Study 4 investigated the relationship between DAT and depression in PD. METHODS: Brain SPECT imaging was undertaken using the DAT radiotracer [99mTc]-TRODAT-1 at baseline to determine pre-synaptic dopaminergic dysfunction. Patients were followed-up, and a final clinical diagnosis was made. RESULTS: In study 1, convincing evidence showed that molecular imaging can reduce diagnostic uncertainty in PD. In study 2, disagreement rate between SPECT imaging versus golden standard clinical diagnosis reached 20%. Sensitivity and specificity (DAT scan) were, respectively, 100 and 70%. However, in study 3, two out of five subjects with psychogenic Parkinsonism had DAT densities under the cut-off suggesting a degenerative Parkinsonism. In study 4, DAT density was greater in PD patients with depression. CONCLUSIONS: This thesis confirmed the useful role of molecular imaging in CUCP, and provided in vivo information about different underlying PD-related physiopathology mechanisms.
Preview · Article · May 2012 · Arquivos de neuro-psiquiatria
[Show abstract][Hide abstract] ABSTRACT: Cognitive and olfactory impairments have previously been demonstrated in patients with spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease (MJD)-SCA3/MJD. We investigated changes in regional cerebral blood flow (rCBF) using single-photon emission computed tomography (SPECT) imaging in a cohort of Brazilian patients with SCA3/MJD. The aim of the present study was to evaluate the correlation among rCBF, cognitive deficits, and olfactory dysfunction in SCA3/MJD. Twenty-nine genetically confirmed SCA3/MJD patients and 25 control subjects were enrolled in the study. The severity of cerebellar symptoms was measured using the International Cooperative Ataxia Rating Scale and the Scale for the Assessment and Rating of Ataxia. Psychiatric symptoms were evaluated by the Hamilton Anxiety Scale and Beck Depression Inventory. The neuropsychological assessment consisted of Spatial Span, Symbol Search, Picture Completion, the Stroop Color Word Test, Trail Making Test (TMT), and Phonemic Verbal Fluency. Subjects were also submitted to odor identification evaluation using the 16-item Sniffin' Sticks. SPECT was performed using ethyl cysteine dimer labeled with technetium-99m. SCA3/MJD patients showed reduced brain perfusion in the cerebellum, temporal, limbic, and occipital lobes compared to control subjects (pFDR <0.001). A significant positive correlation was found between the Picture Completion test and perfusion of the left parahippocampal gyrus and basal ganglia in the patient group as well as a negative correlation between the TMT part A and bilateral thalamus perfusion. The visuospatial system is affected in patients with SCA3/MJD and may be responsible for the cognitive deficits seen in this disease.
[Show abstract][Hide abstract] ABSTRACT: The cerebellum is no longer considered a purely motor control device, and convincing evidence has demonstrated its relationship to cognitive and emotional neural circuits. The aims of the present study were to establish the core cognitive features in our patient population and to determine the presence of Cerebellar Cognitive Affective Syndrome (CCAS) in this group. We recruited 38 patients with spinocerebellar ataxia type 3 (SCA3) or Machado–Joseph disease (MJD)-SCA3/MJD and 31 controls. Data on disease status were recorded (disease duration, age, age at onset, ataxia severity, and CAG repeat length). The severity of cerebellar symptoms was measured using the International Cooperative Ataxia Rating Scale and the Scale for the Assessment and Rating of Ataxia. The neuropsychological assessment consisted of the Mini-Mental State Examination, Clock Drawing Test, Wechsler Adult Intelligence Scale, Rey–Osterrieth Complex Figure, Wisconsin Card Sorting Test, Stroop Color–Word Test, Trail-Making Test, Verbal Paired Associates, and verbal fluency tests. All subjects were also submitted to the Hamilton Anxiety Scale and Beck Depression Inventory. After controlling for multiple comparisons, spatial span, picture completion, symbol search, Stroop Color–Word Test, phonemic verbal fluency, and Trail-Making Tests A and B were significantly more impaired in patients with SCA3/MJD than in controls. Executive and visuospatial functions are impaired in patients with SCA3/MJD, consistent with the symptoms reported in the CCAS. We speculate on a possible role in visual cortical processing degeneration and executive dysfunction in our patients as a model to explain their main cognitive deficit.