Adaptation of feedforward movement control is abnormal in patients with cervical dystonia and tremor

Objective

It is under debate whether the cerebellum plays a role in dystonia pathophysiology and in the expression of clinical phenotypes. We investigated a typical cerebellar function (anticipatory movement control) in patients with cervical dystonia (CD) with and without tremor.

The impact of ethnicity on the clinical presentations of spinocerebellar ataxia type 3

BackgroundFor a variety of sporadic neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis, it is well-established that ethnicity does affect the disease phenotypes. However, how ethnicity contributes to the clinical symptoms and disease progressions in monogenetic disorders, such as spinocerebellar ataxia type 3 (SCA3), remains less studied.MethodsWe used multivariable linear and logistical regression models in 257 molecularly-confirmed SCA3 patients (66 Caucasians, 43 African Americans, and 148 Asians [composed of 131 Chinese and 17 Asian Americans]) to explore the influence of ethnicity on age at onset (AAO), ataxia severity, and non-ataxia symptoms (i.e. depression, tremor, and dystonia).ResultsWe found that Asians had significantly later AAO, compared to Caucasians (β = 4.75, p = 0.000) and to African Americans (β = 6.64, p = 0.000) after adjusting for the pathological CAG repeat numbers in ATXN3. African Americans exhibited the most severe ataxia as compared to Caucasians (β = 3.81, p = 0.004) and Asians (β = 4.39, p = 0.001) after taking into consideration of the pathological CAG repeat numbers in ATXN3 and disease duration. Caucasians had a higher prevalence of depression than African Americans (β = 1.23, p = 0.040). Ethnicity had no influence on tremor or dystonia.ConclusionsEthnicity plays an important role in clinical presentations of SCA3 patients, which could merit further clinical studies and public health consideration. These results highlight the role of ethnicity in monogenetic, neurodegenerative disorders.     

Grafts of dissociated cerebellar cells containing Purkinje cell precursors organize into zebrin I defined compartments

Summary A prominent feature of the mammalian cerebellum is its organization into parasagittal compartments. One marker of such compartments is the zebrin I molecule that is expressed by bands of Purkinje cells (PC). In order to understand better the basis for the development of this organization, we have transplanted dissociated rat cerebellar anlage, taken during the period of proliferation of PC precursors, into kainic acid lesioned adult rat cerebellum. As previously observed, the resultant grafts exhibited trilaminar structures reminiscent of the normal cerebellum. In every case, the PC in the resultant grafts were organized into zebrin I + and — compartments. In one case, most of the grafted PC were integrated into a region of PC deficient host molecular layer that was induced by pretreatment with kainic acid. Clear bands defined by zebrin I reactivity were seen where groups of the grafted PC had entered the host molecular layer. These bands did not correlate in distribution or size with host bands. Hypotheses compatible with these findings that involve specific and non-specific aggregation of PC are discussed.     

The olivocerebellar projection in normal (+ / +), heterozygous weaver (wv/ +), and homozygous weaver (wv/wv) mutant mice: comparison of terminal pattern and topographic organization

Olivocerebellar organization and topography were analyzed in adult normal (+ / +), heterozygous weaver (wv/+), and homozygous weaver (wv/wv) mutant mice. The two genotypes (wv/+ and wv/wv) of the weaver mutant present a gradation of abnormal cerebellar morphology. Purkinje cell (PC) ectopia ranges from mild (wv/+) to moderate (wv/wv), and regional PC loss is also graded in the two types. To determine olivocerebellar organization and topography, tritiated amino acids were placed into different regions of the inferior olivary complex (IO) in normal, heterozygous, and homozygous weaver mice. Despite some PC loss and ectopia, olivocerebellar fiber (OCF) terminals in both homozygous and heterozygous weaver mice have an orthogonal distribution and topography similar to that seen in normal mice. Differences in OCF termination, such as an increased density of OCF terminal label in the lower portion of the molecular layer, the PC, and granule cell layers, are seen in homozygous weaver mice. In some heterozygous weaver and normal cases, multiple injections labeling most IO cells on one side of the IO resulted in continuous OCF terminal labeling in many regions of the contralateral cerebellar cortex, suggesting that all PCs receive OCF input. Retrograde analysis involving injections of horseradish peroxidase conjugated to wheat germ agglutinin into different mediolateral cerebellar regions in homozygous weaver mice further demonstrates a generally normal olivocerebellar topography.     

Chronological changes in nonhaemorrhagic brain Infarcts with short T1 in the cerebellum and basal ganglia

Our purpose was to investigate nonhaemorrhagic infarcts with a short T1 in the cerebellum and basal ganglia. We carried out repeat MRI on 12 patients with infarcts in the cerebellum or basal ganglia with a short T1. Cerebellar cortical lesions showed high signal on T1-weighted spin-echo images beginning at 2 weeks, which became prominent from 3 weeks to 2 months, and persisted for as long as 14 months after the ictus. The basal ganglia lesions demonstrated slightly high signal from a week after the ictus, which became more intense thereafter. Signal intensity began to fade gradually after 2 months. High signal could be seen at the periphery until 5 months, and then disappeared, while low or isointense signal, seen in the central portion from day 20, persisted thereafter. Received: 1 February 1999 Accepted: 13 September 1999     

Invited. Fukuyama congenital muscular dystrophy: A neuroradiologic review

We reviewed neuroradiologic findings of Fukuyama congenital muscular dystrophy (FCMD) and correlated them with the known neuropathology. All patients showed thick and bumpy cortices with shallow sulci corresponding to polymicrogyria, and approximately half of the patients showed pachygyric cortex with smooth surface corresponding to type II lissencephaly. The two types of cortical dysplasias presented characteristic distributions: the former demonstrated frontal lobe involvement in all and parietotemporal lobe involvement in some, whereas the latter involved the temporo-occipital lobes. Most patients showed prolonged T1 and T2 signal in the white matter, which was indistinct in neonates and infrequently seen in adolescents. Cerebellar polymicrogyria depicted as disorganized cerebellar foliation accompanying cysts were found more than 90% of the patients. In conclusion, brain MRI demonstrates findings consistent with the known neuropathology of FCMD. The detection of the two types of cerebral cortical dysplasia with characteristic distribution and cerebellar abnormalities is helpful in the differential and early diagnosis.