An autopsied case of idiopathic late cortical cerebellar atrophy--comparison with other cortical cerebellar atrophy

A 68-year-old man without familial history developed ataxic gait and sensory disturbance in the lower extremities. At the age of 74, neurological examination revealed marked cerebellar ataxia of all limbs, dysarthria, sensory disturbance of glove and stocking type in the extremities, and slight neurogenic muscular atrophy. There were no mental deterioration and dysautonomia. He died of pneumonia at the age of 74. Neuropathological findings. The cerebellum was decreased in size. Microscopically, there were severe disappearance of Purkinje cells in the cerebellar vermis and hemispheres. The molecular layer, granular cell layer, and cerebellar white matter were preserved. Neurons of the inferior olivary nuclei were also spared. In the spinal cord, there was myelin pallor in the posterior column predominant in Goll's fascicule and moderate atrophy of neurons in the anterior horn. Degeneration of the posterior roots was greater than that of the anterior roots. No abnormal findings were found in the extrapyramidal system, cranial nerves, and cerebrum. We compared this case clinicopathologically with other diseases with cortical cerebellar atrophy; alcoholic cerebellar degeneration, phenytoin intoxication, neuroleptic malignant syndrome, and subacute paraneoplastic cerebellar degeneration. In conclusion, idiopathic late cerebellar cortical atrophy (LCCA) was different clinicopathologically from the other diseases. Especially, LCCA showed the characteristic topography of Purkinje cells loss sparing the molecular and granule cell layers.     

Autosomal dominant cerebellar ataxia (SCA6): clinical, genetic and neuropathological study in a family

We describe a family with dominantly inherited ataxia of late adult onset. Expansion of a CAG repeat in the gene encoding the α_1A voltage-dependent calcium channel was identified at autopsy in one patient, a 65-year-old woman with a disease duration of 11 years. In this patient, pathological changes were confined to the cerebellar cortex and inferior olivary complex. The cerebellar cortex showed severe loss of Purkinje cells with proliferation of Bergmann’s glia, being more pronounced in the superior parts of the vermis and hemispheres. In the inferior olivary complex, a reduced neuronal cell population, which could be interpreted as a change secondary to the cerebellar cortical lesion, was evident. We conclude that the pathological phenotype of this newly classified autosomal dominant cerebellar ataxia, SCA6, is cerebello-olivary atrophy, or more strictly cerebellar cortical atrophy. Received: 27 May 1997 / Revised, accepted: 27 October 1997     

MM2-thalamic-type sporadic Creutzfeldt-Jakob disease with widespread neocortical pathology

We report an autopsy case of MM2-thalamic-type sporadic Creutzfeldt-Jakob disease (sCJD) with widespread cerebral neocortical pathology. Initial symptoms were progressive insomnia and mental disturbance. Magnetic resonance imaging revealed no high-signal intensity lesions on diffusion-weighted images and later showed gradually progressive cerebral atrophy. Periodic synchronous discharges and myoclonus were not observed. Upon neuropathologic examination, widespread cerebral neocortical involvement with fine vacuole-type spongiform change was observed. Severe degeneration with almost complete neuronal loss, tissue rarefaction, numerous fat-laden macrophages and hypertrophic astrocytosis of the medial thalamic nucleus was evident. The inferior olivary nucleus showed severe involvement with neuronal loss and hypertrophic astrocytosis. In the cerebellar cortex, moderate depletion of Purkinje neurons was evident, with no spongiform change in the molecular layer and no neuronal loss in the granule cell layer. Immunohistochemistry for prion protein (PrP) revealed widespread synaptic-type deposits with some primitive plaque-type deposits in the cerebral neocortex, basal ganglia and cerebellar cortex. PrP deposition was also observed in the brainstem, particularly the tegmentum, substantia nigra and pontine nucleus, and spinal cord, particularly the posterior horn. In the medial thalamus and inferior olivary nucleus, PrP deposition was sparse. Analysis of the PrP gene showed no mutation but did show methionine homozygosity at polymorphic codon 129. Western blot analysis of protease-resistant PrP indicated the presence of type 2 PrP. We believe that this patient suffered from MM2-thalamic-type sCJD (sporadic fatal insomnia) with widespread cerebral neocortical pathology due to prolonged disease duration. The present case showed different patterns of spongiform degeneration and PrP deposition in the cerebral neocortex than those in previously reported MM2-thalamic-type sCJD cases.     

Experimental evidence for climbing fibers in the avian cerebellum

This study identifies climbing fibers in the cerebellar cortex following brain stem lesions. Antegrade nerve fiber degeneration was studied after electrolytic destruction of rhombencephalic structures in 24 domestic fowl. Direct damage to the cerebellum was precluded by a retropharyngeal surgical approach. Only lesions that include the inferior olivary nucleus were compatible with Fink-Heimer staining of degenerating nerve fibers in the Purkinje cell and molecular layers. Degenerating axons were identified as climbing fibers from their trajectory in association with Purkinje cell soma and dendrites. Terminal nerve endings were observed only in the basal one-third to one-half of the molecular layer. The presence of climbing fibers in only the contralateral molecular layer was observed in autoradiographic preparations subsequent to unilateral injection of tritiated leucine into the inferior olivary nucleus of three hens. The morphology of the labeled and impregnated degenerating nerve fibers closely coincides with information provided by previous investigators using Golgi stained histological preparations and electron microscopy.     

Transplanted Neurons Alter the Course of Neurodegenerative Disease in Lurcher Mutant Mice

Embryonic cerebellar, neocortical, and striatal tissues derived from NSE-LacZ transgenic mice were transplanted into the right cerebellar hemisphere of 8- to 10-day-oldLurcheror wild-type mice. Host mice survived for 30–90 days and the transplanted tissue was examined by light microscopy using Nissl staining, X-gal histochemistry, and immunohistochemistry for calcium binding protein and glutamic acid decarboxylase. Transplantation of cerebellar tissue, but not neocortical or striatal progenitors, resulted in robust infiltration of the lurcher mutant host cerebellar cortex by transgenic Purkinje neurons. Deep to the infiltrated molecular layer, the host granular layer was thicker and denser than the mutant granular layer, but transgenic cells did not contribute to the spared granular layer. The host inferior olivary complex consistently exhibited a noticeable bilateral asymmetry in Nissl-stained sections. A quantitative analysis of the olivary complex was performed in 10 90-day-old host mice. The results indicate that the left inferior olivary complex of 90-day-old host mice contained more neurons than the right inferior olive of the host mice and contained more neurons than was observed in 90-day-oldLurchercontrol mice. Analysis by olivary subdivision indicates that increased neuron numbers were present in all subdivisions of the host left inferior olive. These studies confirm the specific attractive effect of the mutant cerebellar cortex on transplanted Purkinje neuron progenitors and indicate that neural transplants may survive the neurodegenerative period to interact with developing host neural systems. The unilateral rescue of Lurcher inferior olivary neurons in cerebellar transplant hosts indicates that transplanted neurons may interact with diseased host neural circuits to reduce transneuronal degeneration in the course of a neurodegenerative disease.     

Alcoholic cerebellar degeneration: A clinicopathological study of six Japanese autopsy cases and proposed potential progression pattern in the cerebellar lesion

Alcoholic cerebellar degeneration (ACD) is one of the most common neurological complications in alcoholics. As far as we know, however, only four Japanese autopsy cases of ACD have been reported, and only limited clinicopathological data on this disease are now available in Japan. The aims of this study were: (i) to examine the clinicopathological correlation of six Japanese autopsy cases of ACD, including three asymptomatic cases; and (ii) to elucidate the pattern of progression of the cerebellar lesion in ACD. All six alcoholics were histopathologically diagnosed as having “pure” ACD without Wernicke’s encephalopathy. The characteristics of the topographical distribution of the cerebellar lesion were as follows. Symptomatic cases (cases 1–3) showed more severe and widespread change than asymptomatic cases (cases 4–6). Even in case 6, which had the mildest lesion, the anterior vermis developed a moderate change (Purkinje cell loss and narrowing of the molecular layer). In cases 4 and 5 with more severe and widespread lesions, the superior and posterior vermis and the adjacent regions of the superior hemisphere, including the anterior lobe and simple lobule, were involved. In all symptomatic cases, the anterior superior hemisphere had severe lesions involving the granular cell layer. In contrast to asymptomatic cases, all symptomatic cases also had severe to moderate lesions in the anterior inferior hemisphere. In cases 1 and 2 with the most severe lesions, the moderate to severe changes were distributed in the posterior and inferior portions of both the vermis and hemisphere. These findings suggest that in ACD, severe lesions successively develop: (i) in the anterior superior vermis; (ii) anterior superior hemisphere; (iii) anterior inferior hemisphere; and (iv) anterior inferior vermis. In addition, cerebellar symptoms may frequently occur if the anterior superior hemisphere and anterior inferior hemisphere, in addition to the anterior superior vermis, are involved.     

Krabbe's disease with giant lamellar bodies in Purkinje cells

An autopsy case of Krabbe's disease in a child aged 6 years 7 months 1s reported. Histologically, globoid cells, loss of myelin, oligodendroglia and axons, and marked gliosis were observed in the white matter. In addition, there was severe neuronal loss in the thalamus, pontine nucleus, dentate nucleus and olivary nuclei. The cerebellar cortex showed extensive loss of granular cells and moderate loss of Purkinje cells. There were numerous eosinophilic inclusion bodies, ranging from 2 to 15 m in diameter, in the dendrites of Purkinje cells. The ultrastructural findings for the inclusion bodies were consistent with those of giant lamellar bodies. In addition, smaller lamellar bodies were frequently observed in the perikarya and dendrites. Although loss of granular cells was more prominent in the hemispheres than in the vermis, the inclusion bodies were observed in hemispheres but were infrequently observed in the vermis. They were found in degenerated Purkinje cells which had lost afferent fibers. It is considered that these giant lamellar body inclusions are an unusual type of degenerative structure specific to Purkinje cells.     

An autopsy case of MM2‐cortical + thalamic‐type sporadic Creutzfeldt‐Jakob disease

A 59‐year‐old Japanese man presented with depressed mood, insomnia, abnormal behavior and dementia. Visual and gait disturbance with ataxia also developed. Diffusion‐weighted MRI showed widespread regions of hyperintensity in the bilateral cerebral cortex. The patient died at 62 after a progressive clinical course of 32 months. Myoclonus, periodic sharp‐wave complexes on EEG, and akinetic mutism state were not observed. Neuropathologic examination showed widespread cerebral neocortical involvement with both large confluent vacuole‐type, alongside fine vacuole‐type spongiform changes. Mild spongiform degeneration was observed in the striatum and lateral thalamus. Severe neuron loss with hypertrophic astrocytosis in the medial thalamus and inferior olivary nucleus was present. Cerebral white matter showed diffuse myelin pallor indicating panencephalopathic‐type pathology. In the cerebellar cortex, severe Purkinje neuron loss was observed, but no spongiform degeneration in the molecular layer or neuron loss in the granular cell layer. PrP immunostaining showed widespread perivacuolar‐type PrP, irregular plaque‐like PrP, and synaptic‐type PrP depositions in the cerebral neocortex. Mild PrP deposition was observed in the striatum, lateral thalamus and brainstem, whereas PrP deposition was not apparent in the medial thalamus and inferior olivary nucleus. PrP gene analysis showed no mutations, and methionine homozygosity was observed at codon 129. Western blot analysis of protease‐resistant PrP showed type 2 PrP pattern. MRI and cerebral neocortical pathology suggested MM2‐cortical‐type sporadic Creutzfeldt‐Jakob disease (sCJD), whereas the clinical course and pathology of the medial thalamus and inferior olivary nucleus suggested MM2‐thalamic‐type sCJD. We believe this was a combination of MM2‐cortical‐type and MM2‐thalamic‐type sCJD, which explains the broad spectrum of MM2‐type sCJD findings and symptoms.     

An autopsy case of spinocerebellar ataxia type 6 with mental symptoms of schizophrenia and dementia.

We herein report the findings of an autopsy case of spinocerebellar ataxia type 6 (SCA6) which revealed a mild CAG-repeat expansion in the alpha1A voltage-dependent calcium channel (CACNL1A4) gene on chromosome 19p13. A 39-year-old man who showed slowly progressive mental disorders and gait ataxia was clinically diagnosed to have cortical cerebellar atrophy (CCA) and schizophrenia. None of his relatives revealed any symptoms such as spinocerebellar disease, however, his younger brother had shown some mental disorders. The patient eventually died at 52 years of age, and an autopsy was thus performed. The main histopathological findings included a severe neuronal cell loss of Purkinje cells and inferior olivary nuclei. The number of Purkinje cells in our case had decreased severely in comparison to that in either OPCA or age-matched control cases, and the Purkinje cells in the cerebellar hemisphere were more affected than those in the cerebellar vermis. The neurons of the dentate nucleus and pontine nuclei were well-preserved, and no pathological changes were seen in cerebral cortices or basal ganglia. The clinicopathological findings were similar to those of late cortical cerebellar atrophy (LCCA), Holmes' cortical cerebellar atrophy (Holmes type) or SCA6 cases reported previously. Using genomic DNA extracted from archival paraffin-embedded sections in the frontal lobe, cerebral basal ganglia and cerebellum, the identical mild CAG-repeat expansions in the CACNL1A4/SCA6 gene were revealed in all samples examined. These findings suggest that in cases with LCCA or Holmes type atrophy, we should thus examine the CAG-repeat expansions in the SCA6 gene, and the genomic DNA extracted from paraffin-embedded sections was thus found to be useful in diagnosing SCA6 retrospectively.     

Autopsy case of sporadic Creutzfeldt–Jakob disease presenting with signs suggestive of brainstem and spinal cord involvement

We describe an autopsy case of MM1‐type sporadic Creutzfeldt–Jakob disease (CJD), the duration of which was 93 days. The patient was a 59‐year‐old Japanese man with no family history of prion disease or known iatrogenic exposure to CJD. His first symptom was dysesthesia in the left arm, suggestive of cervical cord involvement, and he showed rapidly progressive neurologic signs, such as dysarthria, dysphagia, lethargy, sleep apnea and respiratory failure, suggestive of brainstem involvement. Progressive mental deterioration combined with episodes of myoclonic seizure and periodic synchronous discharges on the electroencephalogram were observed in the later disease stage. Autopsy showed typical spongiform change to be widespread in the cerebral and cerebellar cortices, thalamus and basal ganglia. Synaptic‐type PrP deposition was marked in the cerebral cortex, thalamus and basal ganglia. In the cerebellum, although the granular, molecular and Purkinje cell layers were well preserved from neuronal loss and gliosis, PrP deposition was marked in the molecular and granular cell layers. Spongiform degeneration and neuronal loss were not seen in the brainstem and spinal cord, but relatively marked PrP deposition was observed in the quadrigeminal body, substantia nigra, pontine nucleus, inferior olivary nucleus and posterior horn. Immunohistochemical staining for HLA‐DR showed proliferation of activated microglia in the cerebral and cerebellar cortices, pontine nucleus, inferior olivary nucleus and posterior horn. The mechanisms underlying the neurologic symptoms and signs were unclear, but we speculate that, in addition to widespread involvement of the cerebral cortex, PrP deposition and microglial activation in the brainstem and spinal cord were responsible.     

Histopathological and ultrastructural features of feline hereditary cerebellar cortical atrophy: a novel animal model of human spinocerebellar degeneration

Human spinocerebellar degeneration is one of the intractable diseases. We studied the detailed neuropathology of cats with hereditary cerebellar degeneration obtained from the experimental breeding. The findings included almost total loss of Purkinje cells with an increase in Bergmann’s glia in the cerebellar hemisphere, preservation of some Purkinje cells in the vermis and moderate neuronal depletion of the olive nucleus. Cerebellar and pontine nuclei were normal. The cerebrum and spinal cord as well as the peripheral nervous system appeared normal. Electron microscopic examination revealed swelling of the distal dendrites of Purkinje cells in the less-affected nodule of the vermis, and clusters of presynaptic boutons without any synaptic contact in the severely affected folia where Purkinje cell bodies and dendrites disappeared. Prolonged existence of presynapses in the molecular and Purkinje cell layers was confirmed by positive immunoreactivity to anti-synaptophysin. Quantitative analysis using electron microscopy demonstrated an apparent increase in the density and mean size of presynapses in the molecular layer of the severely affected folia. These findings indicate that degeneration of Purkinje cells started at the most distal part of the dendrite in this animal model of cerebellar degeneration, and that presynapses, axon terminals of the granular cells and basket cells can exist for a long time even after complete degeneration of the Purkinje cells. Further investigation of this novel animal model may promote a better understanding of pathogenesis of human hereditary cerebellar degeneration. Received: 5 January 1998 / Revised, accepted: 20 March 1998     

Congenital olivopontocerebellar atrophy: report of two siblings with paleo- and neocerebellar atrophy

We report two sisters with congenital olivopontocerebellar atrophy, including immunohistochemical studies of autopsy brain tissue. Both cases showed microcephaly with disproportionately marked hypoplasia of the posterior fossa structures including pons, inferior olivary nuclei, and cerebellum. Microscopically, the pons was atrophic with near total loss of pontine nuclei and transverse pontocerebellar tracts (inferior and middle cerebellar peduncles). The medulla showed absent inferior olivary and arcuate nuclei. The cerebellum showed hypoplasia with rudimentary dentate nuclei, profound loss of Purkinje cells and external granule cell layer, a sparse internal granule cell layer of the entire dorsal vermis and the dorsal portions of the lateral folia, as well as markedly reduced underlying axon fibers in the white matter with marked astrogliosis. These features were highlighted by immunohistochemical study using antibodies against Purkinje cell epitopes, synaptophysin, neurofilament, glial fibrillary acidic protein, and tuberin. The cerebral hemispheres were unremarkable. Our cases are characterized by a pattern of diffuse posterior cerebellar involvement that has rarely been described in previous reports. An autosomal recessive pattern of inheritance is suggested. The abnormalities may result from antenatal degeneration or atrophy of neurons in the involved sites rather than hypoplasia or developmental arrest starting in the second and third month of late embryonic life. Received: 24 November 1997 / Revised, accepted: 16 February 1998     

Paraneoplastic cortical cerebellar degeneration

Summary A case is described of paraneoplastic cortical cerebellar degeneration in a patient with a small cell carcinoma of the lung. Following therapy, clinical improvement of cerebellar ataxia had been observed. The most severe degeneration was found in the superior aspects of the vermis and in the anterior and simple lobes as well as in the inferior aspects of the hemisphere. In addition to this distribution of degenerative lesions, uneven loss of Purkinje cells was apparent. Such distribution patterns in this case were apparently compatible with those of alcoholic cortical cerebellar degeneration (ACD), although the lesions were less severe than in ACD. Furthermore, dendritic changes in the Purkinje cells including loss of the spiny branchlets, focal swelling of the dendrites, and disappearance of secondary and tertiary branches were remarkable. It is noteworthy that these cells showed various stages of degeneration before cell loss occurred. These data suggest that the degree of vulnerability varies among Purkinje cells, and that this could be related to the uneven loss of these cells. It is proposed that, although this case and cases of ACD have both similarities and differences in their neuropathological aspects, it is apparent that both conditions have some common morphopathogenetic factor.     

Synapses in the hereditary ataxias.

The goal of this investigation was the systematic assessment of synapses in the hereditary ataxias by the immunocytochemical and immunofluorescent visualization of SNAP-25, a protein of the presynaptic membrane. Sections were prepared from the cerebellar cortex, dentate nucleus, basis pontis, inferior olivary nuclei, and the spinal cord in 57 cases of autosomal dominant and recessive ataxia. The neuropathological phenotype included 18 cases of olivopontocerebellar atrophy (OPCA), 14 cases of familial cortical cerebellar atrophy (FCCA), 4 cases of Machado-Joseph disease (MJD), and 21 cases of Friedreich's ataxia (FA). Among the autosomal dominant ataxias, spinocerebellar ataxia type 1 (SCA-1), SCA-2, MJD/SCA-3, and SCA-6 were represented. Expanded guanine-adenine-adenine trinucleotide repeats were confirmed in 7 patients with FA. The abundance of SNAP-25 was estimated by comparing the fluorescence of the regions of interest to that of the frontal cortex, which was considered unaffected by the disease process. Despite severe Purkinje cell loss, abundant SNAP-25 reaction product remained in the molecular layer of FCCA and OPCA. Among the cases of OPCA, those identified as SCA-2 showed the most severe overall synaptic destruction in cerebellum and brain stem. In SCA-1, which caused either OPCA or FCCA, significant synaptic loss was restricted to the inferior olivary nuclei. Sparing of cerebellar cortex and inferior olivary nuclei was the rule for MJD/SCA-3 and FA, though the dentate nucleus showed reduced SNAP-25 immunoreactivity in both ataxias. In FA, preservation of SNAP-25 in the dentate nucleus was characteristic of long survival. Severe cases with short survival revealed synaptic depletion of the dentate nucleus. At the level of the spinal cord, synaptic loss in the dorsal nuclei of Clarke characterized FA and MJD/SCA-3. The inexorable clinical progression of the hereditary ataxias could not be attributed to synaptic loss in a single anatomic structure of cerebellum, brain stem, or spinal cord. Nevertheless, synaptic loss in dentate and inferior olivary nuclei correlated more precisely with the severity of the ataxia than the changes in the cerebellar cortex.     

Hypertrophic olivary degeneration and Purkinje cell degeneration in a case of long-standing head injury

A case is reported of a 52 year old man who sustained a head injury and survived for three years and two months in coma. He was subsequently shown to have severe brain stem damage, with a bilateral lesion of the central tegmental tract and bilateral hypertrophic olivary degeneration, associated with a widespread loss of Purkinje cells in the cerebellar cortex. Hypertrophic olivary degeneration is considered to be a trans-synaptic change associated with a lesion of the central tegmental tract, which in this case was thought to be due to primary shearing injury of the brain stem involving the superior cerebellar peduncles. It is suggested that, as a consequence of long survival, Purkinje cell degeneration represents further trans-synaptic changes, the result of neuronal degeneration in the hypertrophied inferior olivary nuclei and in the dentate nuclei. A chain or `circuit' of degenerated neurones is thereby produced.     

Kearns-Sayre syndrome: unusual pattern of expression of subunits of the respiratory chain in the cerebellar system

Kearns-Sayre syndrome (KSS) is a sporadic multisystem disorder of oxidative phosphorylation associated with clonally expanded rearrangements of mitochondrial DNA (mtDNA). Mitochondrial dysfunction in the central nervous system of patients with KSS accounts for the neurological manifestations of the disease. To gain further insight into the pathogenesis of neuronal dysfunction in KSS, we used antibodies against mtDNA-encoded and nuclear DNA-encoded subunits of the mitochondrial respiratory chain to study the expression of these proteins in the cerebellar cortex, dentate nucleus, and inferior olivary nucleus from 2 autoptic cases of KSS. Neuropathological examination showed a moderate loss of Purkinje cells and spongiform degeneration of the cerebellar white matter. By using immunohistochemistry, we found a decreased expression of mtDNA-encoded proteins only in neurons of the dentate nucleus. We suggest that mitochondrial abnormalities in the dentate nucleus in conjunction with loss of Purkinje cells and spongiform degeneration of the cerebellar white matter may be important factors in the genesis of the cerebellar dysfunction in KSS.     

Alzheimer's disease and the cerebellum: a morphologic study on neuronal and glial changes

Structural manifestations of Alzheimer's disease (AD) including neuronal loss were investigated in 12 cases of AD and in 10 healthy age-matched controls, with focus on the cerebellum. Linear Purkinje cell (PC) density was measured in the vermis and cerebellar hemispheres. Neurons were also counted in the inferior olivary nucleus. In vermis of the AD cases, the mean PC number was significantly lower (p = 0.019) than in the controls. The neurons in the inferior olive were similarly fewer, though not significantly (p = 0.13). Molecular layer gliosis and atrophy in the vermis was clearly severer in AD than in the controls. Features typical of cerebral Alzheimer encephalopathy (plaques, tangles and microvacuolization) were inconspicious. The structural cerebellar changes in the AD cases were thus neuronal loss, atrophy and gliosis, judged to represent the disease process, and with a main involvement in the vermis. This may be reflected in some of the symptoms and signs seen in AD, signs that are generally overlooked or judged to be of noncerebellar origin.     

Clinical, neuropathological, and molecular study in two families with spinocerebellar ataxia type 6 (SCA6)

To clarify the clinical, neuropathological, and molecular characteristics of spinocerebellar ataxia type 6 (SCA6), two unrelated Japanese families with SCA6 were studied. A clinical feature of the two families was late onset "pure" cerebellar ataxia. Pathologically, three SCA6 brains consistently showed Purkinje cell dominant cortical cerebellar degeneration. Morphometric analysis showed that loss of the cerebellar granule cells and inferior olivary neurons were very mild compared with the severity of Purkinje cell loss. There was no obvious ubiquitin immunoreactive nuclear inclusions. All affected patients had identical expanded alleles, and the expansion was also homogeneously distributed throughout the brain without mosaicism. The present study showed that SCA6 is characterised by Purkinje cell dominant cortical cerebellar degeneration, highly stable transmission of the CAG repeat expansion, and lack of ubiquitin immunoreactive nuclear inclusions.     

Purkinje cell neuroaxonal dystrophy similar to nervous mutant mice phenotype in two sibling kittens

Three 4-month-old kittens from the same litter were presented, two of which were exhibiting cerebellar signs. Euthanasia was requested. No cerebellum atrophy was disclosed on necropsy. General cerebellar anatomy was normal, including the thickness of the cortical layers, myelination, and neurons of the deep cerebellar nuclei. In the ataxic cat vermis, Purkinje cells were lacking along broad parasagittal bands symmetrically disposed relative to the midline. Many Purkinje cells were also lacking in the hemispheres. The nodulus and the flocculus were normal. Surviving Purkinje cells had frequent main dendrite swellings visible with anti-calbindin and anti-microtubule associated protein. In affected regions, calbindin and phosphorylated neurofilaments immunesera stained numerous axonal torpedoes located in the granular layer and the folial white matter. They were also present in processes of the deep cerebellar nuclei and lateral vestibular nucleus. Loss of synaptic endings onto the neurons of these nuclei was evident. Hypertrophied Purkinje cell recurrent axons and enhanced retrograde synaptic endings were present in the granular layer. Bergmann glia was strongly labeled by anti-GFAP, but no abnormal supplementary fibers were seen. None of these alterations were present in the normal sister. However, abnormal vacuolation of the Purkinje cell main dendrites was evident in all three cats, but not in six unrelated control cats that were 3–6 months old. The inferior olive and pontine nuclei were also normal. The two ataxic cats had a primary Purkinje cell degeneration that shared many common features with the abnormal Purkinje cells of the nervous mutant mouse.