Lower dopamine transporter density in an asymptomatic patient with Kleine-Levin syndrome.

BACKGROUND: Kleine-Levin syndrome (KLS) is a rare disorder whose pathophysiological mechanisms remain unknown. PATIENTS AND METHODS: To investigate dopamine abnormalities in KLS, a [99mTc]-TRODAT-1 single photon emission computerized tomography (SPECT) was performed in a patient with KLS during the asymptomatic period and compared with three matched healthy controls. RESULTS: The patient had 14% lower striatal dopamine transporter binding potential (DAT-BP) compared to the mean DAT-BP of three healthy controls. CONCLUSION: This study provides in vivo evidence for abnormalities in the DAT-BP, suggesting an involvement of the dopaminergic system in the pathophysiology of KLS.

Molecular imaging in hereditary forms of parkinsonism.

The development of in vivo molecular imaging to evaluate the dopamine (DA) system with positron-emission tomography and single photon emission computed tomography has been of key importance on monitoring in vivo nigrostriatal neuronal loss in Parkinson's disease (PD), mostly through assessments of pre- and post-synaptic DA receptors. The discoveries of genes related to hereditary forms of parkinsonism (PARK1, PARK2, PARK6, PARK7 and PARK8) have increased our understanding either of distinct subtypes of clinical expression in PD or its etiology. This article revises current data on molecular neuroimaging of genetic forms of parkinsonism comparing and contrasting its main features with the classical sporadic forms. Awareness of the spectrum variance in the genotype and its respective PD phenotype are useful to distinguish different pathophysiological mechanisms of PD.

Clinical correlates of olfactory dysfunction in spinocerebellar ataxia type 3.

Olfactory dysfunction is a very common and early sign in neurodegenerative disorders, but few data are already available in hereditary ataxias. Our aim was to evaluate the sense of smell in patients with molecular-proven spinocerebellar ataxia type 3 (SCA3). Forty-one patients with SCA3 and 46 control subjects were studied. The sense of smell was tested using the Sniffin's Sticks (SS-16). We also evaluated Mini-Mental State Examination (MMSE) and non-cerebellar symptoms, such as parkinsonism, dystonia, and restless legs syndrome (RLS). The SCA3 group had significantly lower SS-16 scores than controls (11.5 ± 2.4 vs 12.8 ± 1.5, p = 0.003). Multiple linear regression analyses, controlling for age, sex, education, cigarette smoking, and MMSE scores, showed that SCA3 (p = 0.021), sex (p = 0.003) and MMSE scores (p = 0.002) had significant regression coefficients. All the variables taken together were significantly associated with the SS-16 scores (p ≤ 0.001). Although MMSE scores and female sex were stronger predictors of the SS-16 scores than SCA3, subjects with SCA3 had lower scores on the SS-16, regardless of sex or MMSE scores. Additionally, MMSE scores, sex and presence of RLS were the best predictors of SS-16 scores. Overall, our results strengthen that the sense of smell is significantly reduced in patients with SCA3 and that sex, MMSE scores and RLS also influence the SS-16 scores.

Tuberculosis: an uncommon cause of cerebral venous thrombosis?

Several infectious etiologies are related to cerebral venous thrombosis (CVT), but a review of literature showed only few cases related to tuberculosis (TB), and only one with neurological manifestations.We report an unusual case of CVT related to TB and mutation in prothrombin gene. A 38-man black presented abrupt right hemiparestesis, and hemiparesis. Investigations revealed CVT. Cerebral spinal fluid (CSF) examination evidenced an infection by Mycobacterium. He was heterozygous for G20210A prothrombin mutation. Probably, hypercoagulability mechanisms of TB, added to mutation of prothrombin gene increase the risk of CVT.

As mais variadas etiologias infecciosas estão relacionadas a trombose venosa cerebral (TVC), mas revisando-se a literatura há apenas poucos relatos de casos que se devem à tuberculose (TB), sendo que em apenas um deles havia manifestações no sistema nervoso central.Relatamos um caso de TVC associado a TB e a mutação do gene da protrombina. Homem 38 anos, negro, apresentou hemiparestesia de instalação súbita à direita, evoluindo com hemiparesia homolateral. Durante a internação, foi coletado líquor que evidenciou infecção por micobactéria. A pesquisa de trombofilias mostrou positividade somente para mutação do gene da protrombina(G20210A). Provavelmente os mecanismos de hipercoagulabilidade intrínsecos à tuberculose somados à mutação do gene da protrombina, potencializam o risco de TVC.