Huntington's disease (HD) is a rare, neurodegenerative disorder characterized by chorea, behavioral manifestations, and dementia. The aim of this study was to estimate the incidence and prevalence of HD through a systematic review of the literature. Medline and Embase databases were searched using terms specific to HD as well as studies of incidence, prevalence, and epidemiology. All studies reporting the incidence and/or prevalence of HD were included. Twenty original research articles were included. Eight studies examined incidence, and 17 studies examined prevalence. Meta‐analysis of data from four incidence studies revealed an incidence of 0.38 per 100,000 per year (95% confidence interval [CI]: 0.16, 0.94). Lower incidence was reported in the Asian studies (n = 2), compared to the studies performed in Europe, North America, and Australia (n = 6). The worldwide service‐based prevalence of HD, based on a meta‐analysis (n = 13 studies), was 2.71 per 100,000 (95% CI: 1.55–4.72). Eleven studies were conducted in Europe, North American, and Australia, with an overall prevalence of 5.70 per 100,000 (95% CI: 4.42–7.35). Three studies were conducted in Asia, with an overall prevalence of 0.40 per 100,000 (95% CI: 0.26–0.61). Metaregression revealed a significantly lower prevalence of HD in Asia, compared to European, North American, and Australian populations. HD is a devastating neurodegenerative disorder with a higher prevalence in Europe, North America, and Australia than in Asia. The difference in prevalence of this genetic disorder can be largely explained by huntingtin gene haplotypes. © 2012 Movement Disorder Society

Parkinson's disease (PD) is a common progressive neurodegenerative movement disorder. Although motor symptoms are associated with focal loss of substantia nigra dopaminergic neurons, pathological changes in PD are widespread 1 . Dementia in patients with PD is common and patients with Parkinson's disease and dementia (PDD) have involvement of additional cortical regions compared with nondemented PD patients 2 . While PD is not known to directly affect white matter fiber tracts, changes in these tracts may reflect pathology within the neuronal cell bodies from which the axons arise and PDD patients may show different patterns of white matter involvement than PD patients.Diffusion tensor imaging (DTI) non-invasively measures the anisotropic mobility of water in the human brain 3 , which ) and controls (8 M, 7F) underwent cognitive testing and MRI scans. The corpus callosum was divided into four regions and the cingulum into two regions bilaterally to define tracts using the program DTIstudio (Johns Hopkins University) using the fiber assignment by continuous tracking algorithm. Volumetric MRI scans were used to measure white and gray matter volumes. Results: Groups did not differ in age or education. There were no overall FA or MD differences between groups in either the corpus callosum or cingulum pathways. In PD subjects the MMSE score correlated with MD within the corpus callosum. These findings were independent of age, sex and total white matter volume. Conclusions: The data suggest that the corpus callosum or its cortical connections are associated with cognitive impairment in PD patients. RÉSUMÉ: La tractographie du corps calleux et du cingulum dans la maladie de Parkinson.Contexte : Dans la maladie de Parkinson, il est bien connu que la perte cellulaire dans le locus niger cause des symptômes moteurs; cependant, il se produit des changements anatomopathologiques étendus qui peuvent être associés à des symptômes qui ne sont pas moteurs tels une atteinte cognitive. L'imagerie en tenseur de diffusion est une méthode d'imagerie quantitative qui est sensible à la microstructure des faisceaux de la substance blanche. Objectif : Le but de l'étude était de mesurer l'anisotropie fractionnelle (AF) et la diffusivité moyenne (DM) dans les voies du corps calleux et du cingulum, définies par la tractographie en tenseur de diffusion, chez des patients atteints de la MP, de la MP accompagnée de démence ( Le corps calleux était divisé en quatre régions et le cingulum en deux régions bilatéralement pour définir les voies au moyen du programme DTIstudio (Johns Hopkins University) utilisant l'algorithme de "tracking" de fibres continu pour l'organisation des faisceaux. Des scans IRM volumétriques ont été utilisés pour mesurer le volume de la substance blanche et de la substance grise. Résultats : L'âge et le niveau de scolarité des différents groupes étaient semblables. Il n'y avait pas de différences de FA ou de MD entre les groupes dans les voies du corps calleux ou du cingulum. Chez les sujets atteints de la MP, les scores...

Corpus callosum area has been examined in neurodegenerative diseases as a marker for cortical pathology and for differential diagnosis; however, it has not been examined in Parkinson’s disease (PD). We compared callosal area in patients with PD and PD with dementia (PDD) to healthy controls and patients with Alzheimer’s disease (AD). We subsequently compared our results to a meta-analysis of studies examining callosal area in AD, frontotemporal dementia (FTD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). For the imaging study, midsagittal T₁-weighted MRIs were analyzed and the callosal area was determined in patients with PD (n = 24), PDD (n = 25), AD (n = 16) and controls (n = 27). The meta-analysis combined results from all publications (Medline or PubMed) representing unique samples and measuring callosal area in AD, FTD, PSP, and CBD. We found that PD and PDD patients did not show statistically significant callosal atrophy compared to controls (effect size d, 95% CI, d = 0.13, –0.26 to 0.52, and d = 0.05, –0.44 to 0.33, respectively) or AD. The AD patients had a significant loss of callosal area compared to controls (d = –0.58, –1.01 to –0.15). Dementia severity was correlated with total callosal atrophy in AD (R = 0.66, p < 0.01) but not in PDD patients (R = 0.18, p > 0.1). The meta-analysis revealed significant combined effect sizes for callosal atrophy of: AD (d = –1.03, –1.13 to –0.93), FTD (d = –1.21, –1.56 to – 0.86), PSP (d = –1.09, –1.38 to –0.81), and CBD (d = –1.80, –2.18 to –1.43). We conclude that PD and PDD patients do not have callosal atrophy in contrast to other neurodegenerative diseases, including AD. Callosal atrophy was correlated with dementia severity in patients with AD but not PDD.

Background:Diagnostic considerations for juvenile onset Parkinsonism (onset at <21 years of age) include juvenile Huntington disease, Wilson disease, dentatorubral-pallidoluysian atrophy (DRPLA), storage diseases, and mitochondrial cytopathies. Neuronal Intranuclear Inclusion Disease (NIID) must also be considered.Case Report:We present a case of juvenile onset NIID with a predominantly Parkinsonian presentation, followed later by corticospinal, cerebellar, and lower motor neuron symptoms.Conclusion:Diagnosis of NIID can be made antemortem through rectal biopsy, however it was missed in this case. Rectal biopsy should be performed in all suspected cases, reviewed by an experienced neuropathologist and repeated if the suspicion for NIID is high. Pathologically, SUMO-1 immunohistochemistry appears to reliably label the neuronal inclusions and abnormal SUMOylation may play a part in the pathogenesis.

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