Olivopontocerebellar atrophy

Multiple system atrophy: a review of 203 pathologically proven cases

We report the clinicopathological features of 203 cases of pathologically proven multiple system atrophy (MSA) from 108 publications up to February 1995. The majority of patients showed symptoms in their early fifties, and men were more commonly affected than women (ratio of 1.3:1). Most patients suffered from some degree of autonomic failure (74%). Parkinsonism was the most common motor disorder (87%), followed by cerebellar ataxia (54%) and pyramidal signs (49%). The response to levodopa was poor in most patients, but there was a subgroup with a good response, who also often developed axial levodopa-induced dyskinesias. Other characteristic features included severe dysarthria, stridor, and, in a few patients, contractures and dystonia (antecollis). Mild or moderate intellectual impairment occurred in some cases, but severe dementing illness was most unusual. The main pathological change comprised cell loss and gliosis in the putamen, caudate nucleus, external pallidum, substantia nigra, locus ceruleus, inferior olives, pontine nuclei, cerebellar Purkinje cells, and intermediolateral cell columns of the spinal cord. However, other neuronal populations were also involved to varying degrees, such as the thalamus, vestibular nucleus, dorsal vagal nucleus, corticospinal tracts, and anterior horn cells. Characteristic glial and/or neuronal cytoplasmic inclusions were identified in all cases in which they were sought, irrespective of clinical presentation. Akinesia correlated with the degree of nigral and putaminal cell loss, whereas rigidity was related only to the later. Tremor was unrelated to cell loss at any site. Ataxia correlated with the degree of olivopontocerebellar atrophy. Pyramidal signs were associated with pyramidal tract pallor. Our analysis also confirmed an association of postural hypotension with intermediolateral cell column degeneration.

Clinicopathology of spinocerebellar degeneration: its correlation to the unstable CAG repeat of the affected gene

The recent advances in gene analysis have greatly facilitated the classification of autosomal dominant spinocerebellar ataxia (SCA). Analyses of linkage in large families with SCA have assigned gene foci to at least 8 chromosomes. One gene is located in the short arm of chromosome 6 (6p22-p23) and causes spinocerebellar ataxia type 1 (SCA1). A gene in the long arm of chromosome 14 (14q24.3-q32) underlies Machado-Joseph disease (MJD). A third gene locus is assigned to the short arm of chromosome 12 (12p2-pter) causing dentatorubropallidoluysian atrophy (DRPLA). The gene for spinocerebellar ataxia type 2 (SCA2) is located in the 12q23-24. Subsequently, a sporadic counterpart of hereditary olivopontocerebellar atrophy of the Menzel type is clearly defined, and all the syndromes (non-hereditary olivopontocerebellar atrophy, striatonigral degeneration and Shy-Drager syndrome) are now lumped under the term of multiple system atrophy (MSA). Oligodendroglial cytoplasmic inclusions appear to be specific for and diagnostic of MSA. As the clinical features in SCA are variable and often appear to overlap with one another, which makes accurate classification difficult if not possible, the genotype is required for their unequivocal classification. However, major neuropathological features clearly distinguish SCA1 from SCA3/ MJD cases; the medial segment of the globus pallidus and intermediolateral column lesions in SCA3/MJD, and inferior olive and cerebellar cortical degeneration in SCA1. It has been stated that neurodegeneration in SCA3/MJD is more homogeneous than in SCA1 or SCA2 and that degeneration of the pallidoluysian system is not present in the latter. The pertinent pathology in each of the three types of SCA is illustrated. The background of clinicopathology and genetic analysis of dentatorubropallidoluysian atrophy is also reviewed.

Presynaptic parkinsonism in olivopontocerebellar atrophy: clinical, pathological, and neurochemical evidence

The substrate for olivopontocerebellar atrophy parkinsonism is obscure due to the lack of clinical and pathological reports and the absence of studies on dopamine receptors in this entity. We describe a patient with olivopontocerebellar atrophy whose clinical presentation was levodopa-responsive parkinsonism in whom pathological examination disclosed pronounced nigral cell loss with no striatal damage. Autoradiographic labeling with 3H-spiperone showed normal densities of D2 dopamine striatal receptors. These data show that indistinguishable nigral, presynaptic parkinsonism occurs in patients with idiopathic Parkinson's disease and in patients with olivopontocerebellar atrophy, and also how a favorable response to levodopa is neither synonymous with idiopathic Parkinson's disease, nor does it exclude multiple-system, atrophy-related parkinsonism.

Degeneration of the corticopontine tract in olivopontocerebellar atrophy

Nine cases of sporadic olivopontocerebellar atrophy [Déjérine-Thomas type, multisystemic atrophy (MSA)] were examined histologically and electron microscopically with special reference to the corticopontine tract. Five of nine cases showed degeneration of the myelinated nerve fibres in this tract. More severe degeneration of the fibres at the level of the pons than the crus cerebri indicates that degeneration of the fibres may start axodistally. Electron microscopy revealed selective involvement of large fibres in olivopontocerebellar atrophy, in contrast to unselective axonal atrophy in dentatorubropallidoluysian atrophy. The problem whether the degeneration of the tract is primary or secondary due to the loss of the pontine neurons remains open. We believe the former to be most likely. Degeneration of the corticopontine fibres should be added to the list of neuropathological findings in sporadic olivopontocerebellar atrophy.

Olivopontocerebellar atrophy. A review of 117 cases

Fifty-four cases of familial OPCA (FOPCA) and sixty-three cases of sporadic OPCA (SOPCA) have been gathered from the literature. The data concerning age at onset, duration of the disease, frequency of symptoms and the various localizations of lesions have been evaluated. In comparison with SOPCA, the disease begins earlier in FOPCA and lasts longer (P less than 0.001). The differences in the percentages of clinical manifestations and associated lesions are also significant with regard to the greater frequency in FOPCA of abnormal movements, ophthalmoplegia, spinal symptoms and lesions located in the dentate nucleus and spinal cord, except for the pyramidal tract. The clinical signs and symptoms are reviewed, special emphasis being given to dysphagia and urinary incontinence, their relevance having been underestimated in previous studies. After a critical analysis of the classifications in current use, I conclude that that of Greenfield (1954) remains the most appropriate.

"Idiopathic" late onset cerebellar ataxia. A clinical and genetic study of 36 cases

The clinical features of 36 patients with late onset cerebellar ataxia of unknown cause are described. Overall, the age of onset ranged from 30 to 74 years and there was a significant excess of males. The patients were divided into 3 groups on clinical grounds. The first was composed of 12 cases in whom truncal ataxia was more marked than limb ataxia and onset was relatively late (mean 54.75 years); these correspond to the Marie-Foix-Alajouanine type of cerebellar degeneration. The second group contained 6 individuals who had prominent tremor in the upper limbs, both resting and during action. The 18 individuals in the 3rd group were clinically similar to patients previously reported as sporadic examples of olivopontocerebellar atrophy. It was this latter category which contributed to excess of males. None of the patients had similarly affected relatives. Both the 3rd groups, and all 36 cases were compared wih 37 other patients with dominantly inherited late onset cerebellar ataxia in order to establish which clinical features might indicate the presence of new dominant mutations in the "sporadic" cases. Optic atrophy ophthalmoplegia and pigmentary retinal degeneration were more frequent in the familial cases.