A histometrical and comparative study on Purkinje cell loss and olivary nucleus cell loss in multiple system atrophy

Altered Capicua expression drives regional Purkinje neuron vulnerability through ion channel gene dysregulation in spinocerebellar ataxia type 1

Selective neuronal vulnerability in neurodegenerative disease is poorly understood. Using the ATXN1[82Q] model of spinocerebellar ataxia type 1 (SCA1), we explored the hypothesis that regional differences in Purkinje neuron degeneration could provide novel insights into selective vulnerability. ATXN1[82Q] Purkinje neurons from the anterior cerebellum were found to degenerate earlier than those from the nodular zone, and this early degeneration was associated with selective dysregulation of ion channel transcripts and altered Purkinje neuron spiking. Efforts to understand the basis for selective dysregulation of channel transcripts revealed modestly increased expression of the ATXN1 co-repressor Capicua (Cic) in anterior cerebellar Purkinje neurons. Importantly, disrupting the association between ATXN1 and Cic rescued the levels of these ion channel transcripts, and lentiviral overexpression of Cic in the nodular zone accelerated both aberrant Purkinje neuron spiking and neurodegeneration. These findings reinforce the central role for Cic in SCA1 cerebellar pathophysiology and suggest that only modest reductions in Cic are needed to have profound therapeutic impact in SCA1.

Using Deep Brain Stimulation to Unravel the Mysteries of Cardiorespiratory Control

This article charts the history of deep brain stimulation (DBS) as applied to alleviate a number of neurological disorders, while in parallel mapping the electrophysiological circuits involved in generating and integrating neural signals driving the cardiorespiratory system during exercise. With the advent of improved neuroimaging techniques, neurosurgeons can place small electrodes into deep brain structures with a high degree accuracy to treat a number of neurological disorders, such as movement impairment associated with Parkinson's disease and neuropathic pain. As well as stimulating discrete nuclei and monitoring autonomic outflow, local field potentials can also assess how the neurocircuitry responds to exercise. This technique has provided an opportunity to validate in humans putative circuits previously identified in animal models. The central autonomic network consists of multiple sites from the spinal cord to the cortex involved in autonomic control. Important areas exist at multiple evolutionary levels, which include the anterior cingulate cortex (telencephalon), hypothalamus (diencephalon), periaqueductal grey (midbrain), parabrachial nucleus and nucleus of the tractus solitaries (brainstem), and the intermediolateral column of the spinal cord. These areas receive afferent input from all over the body and provide a site for integration, resulting in a coordinated efferent autonomic (sympathetic and parasympathetic) response. In particular, emerging evidence from DBS studies have identified the basal ganglia as a major sub-cortical cognitive integrator of both higher center and peripheral afferent feedback. These circuits in the basal ganglia appear to be central in coupling movement to the cardiorespiratory motor program. © 2020 American Physiological Society. Compr Physiol 10:1085-1104, 2020.

Pathological changes in the cerebellum of patients with multiple system atrophy and Parkinson's disease-a stereological study

Multiple system atrophy (MSA) and Parkinson's disease (PD) are synucleinopathies characterized by aggregation of α-synuclein in brain cells. Recent studies have shown that morphological changes in terms of cerebral nerve cell loss and increase in glia cell numbers, the degree of brain atrophy and molecular and epidemiological findings are more severe in MSA than PD. In the present study, we performed a stereological comparison of cerebellar volumes, granule and Purkinje cells in 13 patients diagnosed with MSA [8 MSA-P (striatonigral subtype) and 5 MSA-C (olivopontocerebellar subtype)], 12 PD patients, and 15 age-matched control subjects. Only brains from MSA-C patients showed a reduction in the total number of Purkinje cells (anterior lobe) whereas both MSA-P and MSA-C patients had reduced Purkinje cell volumes (perikaryons and nuclei volume). The cerebellum of both diseases showed a reduction in the white matter volume compared to controls. The number of granule cells was unaffected in both diseases. Analyses of cell type-specific mRNA expression supported our structural data. This study of the cerebellum is in line with previous findings in the cerebrum and demonstrates that the degree of morphological changes is more pronounced in MSA-C than MSA-P and PD. Further, our results support an explicit involvement of cerebellar Purkinje cells and white matter connectivity in MSA-C > MSA-P and points to the potential importance of white matter alterations in PD pathology.

Quantifying iron deposition in the cerebellar subtype of multiple system atrophy and spinocerebellar ataxia type 6 by quantitative susceptibility mapping

We used quantitative susceptibility mapping (QSM) to assess the brain iron deposition in 28 patients with the cerebellar subtype of multiple system atrophy (MSA-C), nine patients with spinocerebellar ataxia type 6 (SCA6), and 23 healthy controls. Two reviewers independently measured the mean QSM values in brain structures including the putamen, globus pallidus, caudate nucleus, red nucleus, substantia nigra, and cerebellar dentate nucleus. A receiver operating characteristics (ROC) analysis was performed to assess the diagnostic usefulness of the QSM measurements. The QSM values in the substantia nigra were significantly higher in the MSA-C group compared to the HC group (p = .007). The QSM values in the cerebellar dentate nucleus were significantly higher in MSA-C than those in the SCA6 and HC groups (p < .001), and significantly lower in the SCA6 patients compared to the HCs (p = .027). The QSM values in the cerebellar dentate nucleus were correlated with disease duration in MSA-C, but inversely correlated with disease duration in SCA6. In the ROC analysis, the QSM values in the cerebellar dentate nucleus showed excellent accuracy for differentiating MSA-C from SCA6 (area under curve [AUC], 0.925), and good accuracy for differentiating MSA-C from healthy controls (AUC 0.834). QSM can identify increased susceptibility of the substantia nigra and cerebellar dentate nucleus in MSA-C patients. These results suggest that an increase in iron accumulation in the cerebellar dentate nucleus may be secondary to the neurodegeneration associated with MSA-C.

Heat Shock Protein Beta-1 Modifies Anterior to Posterior Purkinje Cell Vulnerability in a Mouse Model of Niemann-Pick Type C Disease

Selective neuronal vulnerability is characteristic of most degenerative disorders of the CNS, yet mechanisms underlying this phenomenon remain poorly characterized. Many forms of cerebellar degeneration exhibit an anterior-to-posterior gradient of Purkinje cell loss including Niemann-Pick type C1 (NPC) disease, a lysosomal storage disorder characterized by progressive neurological deficits that often begin in childhood. Here, we sought to identify candidate genes underlying vulnerability of Purkinje cells in anterior cerebellar lobules using data freely available in the Allen Brain Atlas. This approach led to the identification of 16 candidate neuroprotective or susceptibility genes. We demonstrate that one candidate gene, heat shock protein beta-1 (HSPB1), promoted neuronal survival in cellular models of NPC disease through a mechanism that involved inhibition of apoptosis. Additionally, we show that over-expression of wild type HSPB1 or a phosphomimetic mutant in NPC mice slowed the progression of motor impairment and diminished cerebellar Purkinje cell loss. We confirmed the modulatory effect of Hspb1 on Purkinje cell degeneration in vivo, as knockdown by Hspb1 shRNA significantly enhanced neuron loss. These results suggest that strategies to promote HSPB1 activity may slow the rate of cerebellar degeneration in NPC disease and highlight the use of bioinformatics tools to uncover pathways leading to neuronal protection in neurodegenerative disorders.

Niemann-Pick type C1 (NPC) disease is an autosomal recessive lipid storage disorder for which there is no effective treatment. Patients develop a clinically heterogeneous phenotype that typically includes childhood onset neurodegeneration and early death. Mice with loss of function mutations in the Npc1 gene model many aspects of the human disease, including cerebellar degeneration that results in marked ataxia. Cerebellar Purkinje cells in mutant mice exhibit striking selective vulnerability, with neuron loss in anterior lobules and preservation in posterior lobules. As this anterior to posterior gradient is reproduced following cell autonomous deletion of Npc1 and is also observed in other forms of cerebellar degeneration, we hypothesized that it is mediated by differential gene expression. To test this notion, we probed the Allen Brain Atlas to identify 16 candidate neuroprotective or susceptibility genes. We confirmed that one of these genes, encoding the small heat shock protein Hspb1, promotes survival in cell culture models of NPC disease. Moreover, we found that modulating Hspb1 expression in NPC mice promoted (following over-expression) or diminished (following knock-down) Purkinje cell survival, confirming its neuroprotective activity. We suggest that this approach may be similarly used in other diseases to uncover pathways that modify selective neuronal vulnerability.

Regional alterations in purkinje cell density in patients with autism

Neuropathological studies, using a variety of techniques, have reported a decrease in Purkinje cell (PC) density in the cerebellum in autism. We have used a systematic sampling technique that significantly reduces experimenter bias and variance to estimate PC densities in the postmortem brains of eight clinically well-documented individuals with autism, and eight age- and gender-matched controls. Four cerebellar regions were analyzed: a sensorimotor area comprised of hemispheric lobules IV-VI, crus I & II of the posterior lobe, and lobule X of the flocculonodular lobe. Overall PC density was thus estimated using data from all three cerebellar lobes and was found to be lower in the cases with autism as compared to controls, an effect that was most prominent in crus I and II (p<0.05). Lobule X demonstrated a trend towards lower PC density in only the males with autism (p = 0.05). Brain weight, a correlate of tissue volume, was found to significantly contribute to the lower lobule X PC density observed in males with autism, but not to the finding of lower PC density in crus I & II. Therefore, lower crus I & II PC density in autism is more likely due to a lower number of PCs. The PC density in lobule X was found to correlate with the ADI-R measure of the patient's use of social eye contact (R² = -0.75, p = 0.012). These findings support the hypothesis that abnormal PC density may contribute to selected clinical features of the autism phenotype.

Opsoclonus-myoclonus syndrome associated with multiple system atrophy

Opsoclonus-myoclonus syndrome (OMS) is well known as a paraneoplastic syndrome or as a parainfectious neurologic complication. However, OMS associated with a neurodegenerative disorder has not been described previously. A 48-year-old woman had been diagnosed as multiple system atrophy-parkinsonian type (MSA-P) based on the findings of dopamine non-responsive parkinsonism with autonomic failure and typical findings on magnetic resonance imaging 5 years ago. She exhibited recurrent asynchronous and arrhythmic myoclonic movements of the upper limbs and abdomen with a very short duration, and involuntary eye movements, which were repetitive, rapid, random, multidirectional, conjugate saccades of irregular amplitude and frequency at rest. Based on hematological and radiological findings, the diagnosis was advanced MSA-P associated with OMS. As far as we are aware, there have not been any previous reports of such a case.

'Essential tremor' or 'the essential tremors': is this one disease or a family of diseases?

There is accumulating evidence that the entity referred to as 'essential tremor' (ET) is not a single disease. It may be a family of diseases better referred to as 'the ETs'. This review will summarize the following evidence: (1) the presence of etiological heterogeneity; (2) the heterogeneity of findings in postmortem studies, thus suggesting several diseases; (3) the recent discussion that age of onset may be an important marker of disease heterogeneity; (4) the clinical expansion of the concept of ET in recent years to include a broader range of tremor phenomenology, other motor features (gait ataxia), other involuntary movements (dystonia), and nonmotor features (cognitive problems, psychiatric problems), some of which could be primary; (5) the heterogeneity of pharmacological response profiles and clinical progression, and (6) the association of ET with Parkinson's disease, Alzheimer's disease, and possibly progressive supranuclear palsy, with the possibility that some ET patients are more predisposed to develop one of these. © 2013 S. Karger AG, Basel.

Purkinje cell axonal anatomy: quantifying morphometric changes in essential tremor versus control brains

Growing clinical, neuro-imaging and post-mortem data have implicated the cerebellum as playing an important role in the pathogenesis of essential tremor. Aside from a modest reduction of Purkinje cells in some post-mortem studies, Purkinje cell axonal swellings (torpedoes) are present to a greater degree in essential tremor cases than controls. Yet a detailed study of more subtle morphometric changes in the Purkinje cell axonal compartment has not been undertaken. We performed a detailed morphological analysis of the Purkinje cell axonal compartment in 49 essential tremor and 39 control brains, using calbindin D28k immunohistochemistry on 100-µm cerebellar cortical vibratome tissue sections. Changes in axonal shape [thickened axonal profiles (P = 0.006), torpedoes (P = 0.038)] and changes in axonal connectivity [axonal recurrent collaterals (P < 0.001), axonal branching (P < 0.001), terminal axonal sprouting (P < 0.001)] were all present to an increased degree in essential tremor cases versus controls. The changes in shape and connectivity were significantly correlated [e.g. correlation between thickened axonal profiles and recurrent collaterals (r = 0.405, P < 0.001)] and were correlated with tremor duration among essential tremor cases with age of onset >40 years. In essential tremor cases, thickened axonal profiles, axonal recurrent collaterals and branched axons were 3- to 5-fold more frequently seen on the axons of Purkinje cells with torpedoes versus Purkinje cells without torpedoes. We document a range of changes in the Purkinje cell axonal compartment in essential tremor. Several of these are likely to be compensatory changes in response to Purkinje cell injury, thus illustrating an important feature of Purkinje cells, which is that they are relatively resistant to damage and capable of mobilizing a broad range of axonal responses to injury. The extent to which this plasticity of the Purkinje cell axon is partially neuroprotective or ultimately ineffective at slowing further cellular changes and cell death deserves further study in essential tremor.

Extensive distribution of glial cytoplasmic inclusions in an autopsied case of multiple system atrophy with a prolonged 18-year clinical course

We describe herein an autopsied case of multiple system atrophy (MSA) with prolonged clinical course of 18 years, and evaluate the extent of neurodegeneration and glial cytoplasmic inclusions (GCIs) in the entire brain of this rare case. A 64-year-old woman presented with typical neurological symptoms and imaging features of MSA. Thereafter, she became bedridden, and breathing was assisted through a tracheostomy for 12 years. She died at the age of 82 after 18 years from the initial symptom. Post mortem examination revealed severe neurodegeneration in the inferior olive, pontine nuclei, substantia nigra, locus ceruleus, putamen and cerebellum. Notably, phosphorylated α-synuclein (p-α-syn)-positive GCIs were found in these areas, but their number was very low. In contrast, the density of GCIs was much higher in such regions as the tectum/tegmentum of the brainstem, pyramidal tracts, neocortices and limbic system, which usually contain a small number of GCIs. Another constituent of GCIs, ubiquitin (Ub) and Ub-associated autophagy substrate p62, were also positive in some GCIs, and distribution of Ub/p62 immunoreactivity was proportionate to that of p-α-syn+ GCIs despite the very long duration of the disease. Furthermore, this case had complicated hypoxic encephalopathy, but p-α-syn+ GCIs were also found in the damaged white matter, indicating the contribution of α-syncleinopathy as well as hypoxic effect to the secondary myelin and axonal loss in the white matter. Together, this rare case suggests the contribution of the disease duration to the prevalence of GCIs, and the possible involvement of the limbic system in extensive-stage disease.

Reduced Purkinje cell number in essential tremor: a postmortem study

BACKGROUND

Clinical and functional imaging evidence suggests that cerebellar dysfunction occurs in essential tremor (ET). In recent postmortem studies, we documented increased numbers of torpedoes (Purkinje cell axonal swellings) in ET patients without Lewy bodies. Purkinje cell loss, however, has never been rigorously assessed.

OBJECTIVE

To quantitatively assess the number of Purkinje cells in brains of ET patients and similarly aged controls.

METHODS

Postmortem cerebellar tissue was available in 14 ET cases (6 with Lewy bodies and 8 without Lewy bodies) and 11 controls. Calbindin immunohistochemistry was performed on paraffin sections of the cerebellum. Images were digitally recorded and blinded measurements of the number of Purkinje cells per millimeter of cell layer (linear density) were made.

RESULTS

Purkinje cell linear density was inversely correlated with age (r= - 0.53, P= .006) and number of torpedoes (r= - 0.42, P= .04). Purkinje cell linear density differed by diagnosis (mean [SD], controls, 3.46 [1.27] cells/mm; ET cases with Lewy bodies, 3.33 [1.06] cells/mm; and ET cases without Lewy bodies, 2.14 [0.82] cells/mm; P= .04), with the most significant difference between ET cases without Lewy bodies and controls, where the reduction was 38.2% (P= .04). In an adjusted linear regression analysis that compared ET cases without Lewy bodies with controls, decreased linear density (outcome variable) was associated with ET (beta= .56, P= .03).

CONCLUSIONS

We demonstrated a reduction in Purkinje cell number in the brains of patients with ET who do not have Lewy bodies. These data further support the view that the cerebellum is anatomically, as well as functionally, abnormal in these ET cases.

Spatiotemporal analysis of purkinje cell degeneration relative to parasagittal expression domains in a model of neonatal viral infection

Infection of newborn Lewis rats with Borna disease virus (neonatal Borna disease [NBD]) results in cerebellar damage without the cellular inflammation associated with infections in later life. Purkinje cell (PC) damage has been reported for several models of early-life viral infection, including NBD; however, the time course and distribution of PC pathology have not been investigated rigorously. This study examined the spatiotemporal relationship between PC death and zonal organization in NBD cerebella. Real-time PCR at postnatal day 28 (PND28) revealed decreased cerebellar levels of mRNAs encoding the glycolytic enzymes aldolase C (AldoC, also known as zebrin II) and phosphofructokinase C and the excitatory amino acid transporter 4 (EAAT4). Zebrin II and EAAT4 immunofluorescence analysis in PND21, PND28, PND42, and PND84 NBD rat cerebella revealed a complex pattern of PC degeneration. Early cell loss (PND28) was characterized by preferential apoptotic loss of zebrin II/EAAT4-negative PC subsets in the anterior vermis. Consistent with early preferential loss of zebrin II/EAAT4-negative PCs in the vermis, the densities of microglia and the Bergmann glial expression of metallothionein I/II and the hyaluronan receptor CD44 were higher in zebrin II/EAAT4-negative zones. In contrast, early loss in lateral cerebellar lobules did not reflect a similar discrimination between PC phenotypes. Patterns of vermal PC loss became more heterogeneous at PND42, with the loss of both zebrin II/EAAT4-negative and zebrin II/EAAT4-positive neurons. At PND84, zebrin II/EAAT4 patterning was abolished in the anterior cerebellum, with preferential PC survival in lobule X. Our investigation reveals regional discrimination between patterns of PC subset loss, defined by zebrin II/EAAT4 expression domains, following neonatal viral infection. These findings suggest a differential vulnerability of PC subsets during the early stages of virus-induced neurodegeneration.

An autopsy case of early ("minimal change") olivopontocerebellar atrophy (multiple system atrophy-cerebellar)

We report a 57-year-old woman with multiple system atrophy (MSA) of 15-month duration. The patient developed dysarthria, followed by impaired balance of gait, mild limb ataxia, and saccadic eye movement. A postmortem examination performed after she was found dead in a bathtub revealed neuronal loss restricted to the olivopontocerebellar system, being more severe in the pontine nucleus. Mild neuronal loss was also found in the anterior vermis and inferior olivary nucleus. Alpha-synuclein immunohistochemistry demonstrated widespread occurrence of glial cytoplasmic inclusions in the central nervous system, which were more numerous in the pontine base and cerebellar white matter. In contrast, neuronal alpha-synuclein accumulation was confined to the pontine and inferior olivary nuclei. The number of neuronal intranuclear inclusions was much higher than that of neuronal cytoplasmic inclusions. Moreover, alpha-synuclein accumulation was more severe in the neurites than in the cytoplasm or nucleus. This case demonstrates the early pattern of brain pathology in MSA-cerebellar (olivopontocerebellar atrophy).

Patterned Purkinje cell death in the cerebellum

The object of this review is to assemble much of the literature concerning Purkinje cell death in cerebellar pathology and to relate this to what is now known about the complex topography of the cerebellar cortex. A brief introduction to Purkinje cells, and their regionalization is provided, and then the data on Purkinje cell death in mouse models and, where appropriate, their human counterparts, have been arranged according to several broad categories--naturally-occurring and targeted mutations leading to Purkinje cell death, Purkinje cell death due to toxins, Purkinje cell death in ischemia, Purkinje cell death in infection and in inherited disorders, etc. The data reveal that cerebellar Purkinje cell death is much more topographically complex than is usually appreciated.

Patterned Purkinje cell degeneration in mouse models of Niemann-Pick type C disease

Niemann Pick disease type C1 (NPC1) is an inherited, autosomal recessive, lipid-storage disorder with major neurological involvement. Purkinje cell death is a prominent feature of the neuropathology of NPC. We have investigated Purkinje cell death in two murine models of NPC1, BALB/c npc(nih) and C57BLKS/J spm. In both cases, extensive Purkinje cell death was found in the cerebellum. The pattern of Purkinje cell death is complex. First, zebrin II-negative Purkinje cells disappear, to leave survivors aligned in stripes that closely resemble the pattern revealed by using zebrin II immunocytochemistry. Subsequently, as the disease progresses, additional Purkinje cells die. At the terminal stages of the disease, the surviving Purkinje cells are concentrated in lobules IX and X of the posterior lobe vermis. Purkinje cell degeneration is accompanied by the ectopic expression of tyrosine hydroxylase and the small heat shock protein HSP25, both associated preferentially with the surviving cells. The pattern of cell death thus reflects the fundamental compartmentation of the cerebellum into zones and stripes.

Mice expressing the alpha(1B)-adrenergic receptor induces a synucleinopathy with excessive tyrosine nitration but decreased phosphorylation

We had previously reported that systemic overexpression of the alpha(1B)-adrenergic receptor (AR) in a transgenic mouse induced a neurodegenerative disease that resembled the parkinsonian-like syndrome called multiple system atrophy (MSA). We now report that our mouse model has cytoplasmic inclusion bodies that colocalize with oligodendrocytes and neurons, are positive for alpha-synuclein and ubiquitin, and therefore may be classified as a synucleinopathy. Alpha-synuclein monomers as well as multimers were present in brain extracts from both normal and transgenic mice. However, similar to human MSA and other synucleinopathies, transgenic mice showed an increase in abnormal aggregated forms of alpha-synuclein, which also increased its nitrated content with age. However, the same extracts displayed decreased phosphorylation of alpha-synuclein. Other traits particular to MSA such as Purkinje cell loss in the cerebellum and degeneration of the intermediolateral cell columns of the spinal cord also exist in our mouse model but differences still exist between them. Interestingly, long-term therapy with the alpha(1)-AR antagonist, terazosin, resulted in protection against the symptomatic as well as the neurodegeneration and alpha-synuclein inclusion body formation, suggesting that signaling of the alpha(1B)-AR is the cause of the pathology. We conclude that overexpression of the alpha(1B)-AR can cause a synucleinopathy similar to other parkinsonian syndromes.

Differentiating multiple system atrophy from Parkinson's disease: contribution of striatal and midbrain MRI volumetry and multi-tracer PET imaging

OBJECTIVES

The differential diagnosis between typical idiopathic Parkinson's disease (PD) and the striatonigral variant of multiple system atrophy (MSA-P) is often difficult because of the presence of signs and symptoms common to both forms of parkinsonism, particularly at symptom onset. This study investigated striatal and midbrain findings in MSA-P and PD patients in comparison with normal controls with the use of positron emission tomography (PET) and three dimensional magnetic resonance imaging (3D MRI) based volumetry to increase the differential diagnostic accuracy between both disease entities.

METHODS

Nine patients with MSA-P, 24 patients with PD, and seven healthy controls were studied by MRI and PET with 6-[(18)F]-fluoro-L-dopa (FDOPA), [(18)F]fluoro-deoxyglucose (FDG), and 11-C-Raclopride (RACLO). Striatal and extrastriatal volumes of interest (VOI) were calculated on the basis of the individual MRI data. The PET data were transferred to the VOI datasets and subsequently analysed.

RESULTS

MSA-P differed significantly from PD patients in terms of decreased putaminal volume, glucose metabolism, and postsynaptic D2 receptor density. The striatal FDOPA uptake was equally impaired in both conditions. Neither MRI volumetry nor PET imaging of the midbrain region further contributed to the differential diagnosis between PD and MSA-P.

CONCLUSIONS

The extent and spatial distribution of functional and morphological changes in the striatum permit the differentiation of MSA-P from PD. Both, multi-tracer PET and 3D MRI based volumetry, may be considered equivalent in the assessment of different striatal abnormality in both disease entities. In contrast, MRI and PET imaging of the midbrain does not provide a further gain in diagnostic accuracy.

Patterns of neuropsychological performance in multiple system atrophy compared to sporadic and hereditary olivopontocerebellar atrophy

Although neuropsychological symptoms are associated with multiple system atrophy (MSA), sporadic olivopontocerebellar atrophy (sOPCA), and dominantly inherited olivopontocerebellar atrophy (dOPCA), the differences between these groups have not been explored. We compared 28 MSA patients on psychiatric rating scales and neuropsychological measures to 67 sOPCA patients, 42 dOPCA patients, and 30 normal controls. Patients with dOPCA, sOPCA, and MSA all exhibited significant deficits on motor-related tasks, as well as relatively mild deficits in cognitive functioning. Patients with MSA had greater neuropsychological dysfunction, particularly in memory and other "higher order" cognitive processes, than patients with either sOPCA or dOPCA.

Progression and prognosis in multiple system atrophy: an analysis of 230 Japanese patients

We investigated the disease progression and survival in 230 Japanese patients with multiple system atrophy (MSA; 131 men, 99 women; 208 probable MSA, 22 definite; mean age at onset, 55.4 years). Cerebellar dysfunction (multiple system atrophy-cerebellar; MSA-C) predominated in 155 patients, and parkinsonism (multiple system atrophy-parkinsonian; MSA-P) in 75. The median time from initial symptom to combined motor and autonomic dysfunction was 2 years (range 1-10). Median intervals from onset to aid-requiring walking, confinement to a wheelchair, a bedridden state and death were 3, 5, 8 and 9 years, respectively. Patients manifesting combined motor and autonomic involvement within 3 years of onset had a significantly increased risk of not only developing advanced disease stage but also shorter survival (P < 0.01). MSA-P patients had more rapid functional deterioration than MSA-C patients (aid-requiring walking, P = 0.03; confinement to a wheelchair, P < 0.01; bedridden state, P < 0.01), but showed similar survival. Onset in older individuals showed increased risk of confinement to a wheelchair (P < 0.05), bedridden state (P = 0.03) and death (P < 0.01). Patients initially complaining of motor symptoms had accelerated risk of aid-requiring walking (P < 0.01) and confinement to a wheelchair (P < 0.01) compared with those initially complaining of autonomic symptoms, while the time until confinement to a bedridden state and survival were no worse. Gender was not associated with differences in worsening of function or survival. On MRI, a hyperintense rim at the lateral edge of the dorsolateral putamen was seen in 34.5% of cases, and a 'hot cross bun' sign in the pontine basis (PB) in 63.3%. These putaminal and pontine abnormalities became more prominent as MSA-P and MSA-C features advanced. The atrophy of the cerebellar vermis and PB showed a significant correlation particularly with the interval following the appearance of cerebellar symptoms in MSA-C (r = 0.71, P < 0.01, r = 0.76 and P < 0.01, respectively), but the relationship between atrophy and functional status was highly variable among the individuals, suggesting that other factors influenced the functional deterioration. Atrophy of the corpus callosum was seen in a subpopulation of MSA, suggesting hemispheric involvement in a subgroup of MSA patients. The present study suggested that many factors are involved in the progression of MSA but, most importantly, the interval from initial symptom to combined motor and autonomic dysfunction can predict functional deterioration and survival in MSA.

Preclinical impairment of the striatal dopamine transporter system in sporadic olivopontocerebellar atrophy: studied with [(123)I]beta-CIT and SPECT

We investigated whether the dopamine (DA) transporter system is impaired in sporadic olivopontocerebellar atrophy (sOPCA) patients without clinical parkinsonism using the DA transporter radiotracer [(123)I]beta-CIT [2beta-carboxymethoxy-3beta-(4-iodophenyl)tropane] and single-photon emission computed tomography (SPECT). SPECT scans were acquired in 9 patients with sOPCA, 7 multiple system atrophy (MSA) patients with parkinsonism (MSA-P), and 7 age-matched healthy controls 20-24 h after the intravenous injection of [(123)I]beta-CIT. [(123)I]beta-CIT-specific binding in the striatum was determined as the radioactivity ratio of the striatum to the occipital cortex (specific binding ratio, SBR). In patients with sOPCA and MSA-P, SBRs in the right and left striatum and the mean SBR were significantly lower than those in controls (p < 0.05). The mean SBRs in patients with sOPCA and MSA-P were reduced to 69.0 and 60.7% of the control mean, respectively. However, there was no significant difference in SBRs between sOPCA and MSA-P patients. In sOPCA patients, the mean SBR was significantly correlated with the score of the clinical cerebellar function scale (r = -0.670, p = 0.024). These results indicate that even in the absence of clinical parkinsonism, the striatal dopaminergic system may be impaired in sOPCA. The DA transporter loss in sOPCA serves as another clue for sOPCA being a part of the spectrum of MSA.

Decreased striatal monoaminergic terminals in multiple system atrophy detected with positron emission tomography

We examined the density of striatal presynaptic monoaminergic terminals, using a ligand for the type 2 vesicular monoamine transporter, (+)-[11C]dihydrotetrabenazine, with positron emission tomography in 7 normal control subjects, 8 multiple system atrophy (MSA) patients with predominantly parkinsonian features (MSA-P), 8 MSA patients with principally cerebellar dysfunction (MSA-C), and 6 sporadic olivopontocerebellar atrophy (sOPCA) patients. The findings were correlated with the results of neurological evaluations and magnetic resonance imaging studies. Specific binding was significantly reduced in the putamen of all patient groups in the order MSA-P < MSA-C < sOPCA, compared with controls. Mean blood-to-brain ligand transport (K1) was significantly decreased in the putamen of all patient groups and in the cerebellar hemispheres of MSA-C and sOPCA but not MSA-P groups, compared with controls. Significant negative correlations were found between striatal binding and the intensity of parkinsonian features and between cerebellar K1 and the intensity of cerebellar dysfunction. The results suggest fundamental differences between MSA-P and MSA-C groups reflecting differential severity of degeneration of nigrostriatal and cerebellar systems in these two forms of MSA. The findings also show that some sOPCA patients have subclinical nigrostriatal dysfunction and are at risk of developing MSA with disease progression.

Differentiating between multiple system atrophy and Parkinson's disease by positron emission tomography with 18F-dopa and 18F-FDG

Both the striatal 18F-dopa uptake and brain glucose metabolism were studied by PET with 6-L-[18F]fluorodopa (FD) and [18F]fluorodeoxyglucose (FDG) in 9 patients with multiple system atrophy (MSA) and 15 patients with idiopathic Parkinson's disease (PD). Five of the 9 MSA patients were diagnosed as having olivopontocerebellar atrophy, whereas 2 had striatonigral degeneration and 2 demonstrated Shy-Drager syndrome. The FD uptake ratios to the occipital cortex in the MSA patients at 120 min after the administration of FD were 2.07 +/- 0.31 (mean +/- SD) and 1.96 +/- 0.29 in the caudate and the putamen, respectively, and decreased compared to those in the controls (2.72 +/- 0.11, 2.71 +/- 0.10). The same ratios in the PD patients were 2.07 +/- 0.36 and 1.74 +/- 0.24, respectively, which also decreased, but the decreased uptake in the putamen was more prominent. The caudate-putamen index (CPI)(%), which was calculated by a formula based on the difference in the uptakes in the caudate and putamen divided by the caudate uptake, indicated 5.6 +/- 4.6 in the MSA patients and 14.8 +/- 5.4 in the PD patients. The CPI for all PD patients was more than 7.0, which was the mean + 2SD for the controls, but the CPI for 3 MSA patients was more than 7.0 (accuracy: 88%). The glucose metabolic rates for each region in the PD patients showed no difference from the normal controls. The frontal and the temporal cortical glucose metabolism and the caudate, the putaminal, the cerebellar and the brainstem glucose metabolism in the MSA patients decreased significantly in comparison to those in the controls. But, as the glucose metabolic rates in such regions of each patient overlapped in the two groups, the accuracy of the FDG study for differentiation was lower than that of the FD study. The putaminal glucose metabolic rates, for example, in 3 PD patients were less than 6.8 (mg/min/100 ml), which was the mean-2SD for the controls, while those in 3 MSA patients were more than 6.8 (accuracy: 75%). In addition, the combination of these two methods slightly improved the accuracy. The glucose metabolism is useful for evaluating the regional metabolic activity of the brain, and the FD study, which is specific to the dopamine system, seems to be more useful for differentiating between MSA and PD.

Decreased striatal monoaminergic terminals in olivopontocerebellar atrophy and multiple system atrophy demonstrated with positron emission tomography

We used [11C]dihydrotetrabenazine, a new ligand for the type 2 vesicular monoamine transporter (VMAT2), with positron emission tomography to study striatal monoaminergic presynaptic terminals in 4 patients with multiple system atrophy, 8 with sporadic olivopontocerebellar atrophy, and 9 normal control subjects. Specific binding in the striatum was significantly reduced in the multiple system atrophy patients as compared with the normal control group, with average reductions of 61% in the caudate nucleus (p = 0.002) and 58% in the putamen (p = 0.009). Smaller reductions were found in the sporadic olivopontocerebellar atrophy group, averaging 26% in the caudate nucleus (p = 0.05) and 24% in the putamen (p = 0.11). Mean blood-to-brain [11C]dihydrotetrabenazine transport (K1) was significantly different between groups only in the cerebellum, with values for the sporadic olivopontocerebellar atrophy group diminished compared with the normal control group. Cerebellar K1 was not significantly decreased in the multiple system atrophy group. The finding of reduced striatal VMAT2 in sporadic olivopontocerebellar atrophy patients suggests nigrostriatal pathology, indicating that some may later develop symptomatic extrapyramidal disease.

Glucose metabolism in the cortical and subcortical brain structures in multiple system atrophy and Parkinson's disease: a positron emission tomographic study

The brain glucose metabolism was studied by PET with 18F-FDG in 11 patients with multiple system atrophy (MSA) and 12 patients with idiopathic Parkinson's disease (PD). Seven of the 11 MSA patients were diagnosed as having olivopontocerebellar atrophy, two had striatonigral degeneration, while two demonstrated Shy-Drager syndrome. The glucose metabolic rates for each region in the PD patients showed no difference from the normal controls. The frontal, temporal and parietal cortical glucose metabolic rates and the caudate, the putaminal, the cerebellar and the brainstem glucose metabolic rates in the MSA patients decreased significantly from the controls. The atrophy of the cerebellum and the brainstem in the MSA patients were scored by MRI. The cerebellar and brainstem glucose metabolism in the MSA patients decreased as the atrophy score in such regions advanced in each group; however, some patients with no atrophy showed a decreased glucose metabolism. Although the cerebellar and the brainstem glucose metabolism decreased in all MSA patients, such a decrease was not observed in the SND patients. The decrease in the glucose metabolism for the non-cortical regions in the MSA patients seems to be due to a diffuse depletion of the neurons not restricted to the nigrostriatal neurons. Deafferentation to the cerebral cortices seems to result in a decreased cortical metabolism. The differences in the glucose metabolism between MSA and PD as assessed by PET may be caused by the pathophysiological differences between MSA and PD, and such differences therefore appear to be useful when making a differential diagnosis between MSA and PD. The relative sparing of the brainstem and cerebellar glucose metabolism is considered to be a feature of patients with SND.

Pathology of the cerebellar dentate nucleus in sporadic olivopontocerebellar atrophy: a morphometric investigation

The pathology of the cerebellar dentate nucleus was investigated by morphometric methods in three patients with sporadic olivopontocerebellar atrophy (sOPCA), and the results were compared to specimens from three subjects without neurological disease (controls). The size of dentate neurons; the number of small and large neurons (50-199 microns2 and larger than 200 microns2, respectively) at rostral, middle, and caudal levels; nerve cell density; total volume of the gray band; and total nerve cell number, were estimated with an image analyzer applied to serial 20-microns-thick sections of one celloidin-embedded cerebellar hemisphere. The number of small neurons in patients with sOPCA was significantly increased at the rostral level while the number of large neurons showed large inter-individual variations. Dentate neurons also showed various qualitative changes such as atrophy and hypertrophy. The nerve cell density in the dentate nucleus was 1.7 times higher in the patients than in the controls. However, the total volume of the gray band was reduced to one-half of that in controls. There were no differences in the total nerve cell number between the patients and controls. This reduction in size of the dentate gray matter in patients with sOPCA may result from the disappearance of afferent nerve fibers originating from Purkinje cells, inferior olivary neurons, and pontine neurons.

Olivopontocerebellar pathology in multiple system atrophy

Olivopontocerebellar atrophy (OPCA) is widely accepted as part of the neuropathological spectrum of multiple system atrophy (MSA). The distribution of affected sites in the olivopontocerebellar (OPC) system and their interrelationship remain poorly understood due to lack of quantitative studies. To further investigate the OPC pathology in MSA, we performed a morphometric analysis of 20 MSA cases and eight healthy controls. In the MSA cases, mean neuronal cell densities were significantly reduced in (medial and dorsal) accessory and principal inferior olives, pontine nuclei, cerebellar vermis (except nodulus), and hemispheres. Inferior olives and pontine nuclei were more severely affected than cerebellar Purkinje cells in most cases. Cerebellar Purkinje cells were more severely depleted in vermis rather than in hemisphere. There was a poor topographic correlation between neuronal cell loss in inferior olives and cerebellar cortex. These results suggest a primary degeneration of olivopontine nuclei and cerebellar Purkinje cells in OPCA. Inferior olives, pontine nuclei and cerebellar cortex were all significantly more severely affected in cases with a pure or predominating cerebellar syndrome (OPCA type, n = 4) compared to those with pure or predominating parkinsonism (SND type, n = 14). However, although cerebellar signs had been noted in life in only six cases, morphometry revealed OPCA in 17 of the 20 MSA brains.

The AMPA antagonist NBQX provides partial protection of rat cerebellar Purkinje cells after cardiac arrest and resuscitation

Purkinje cell loss in adult rats resuscitated following cardiac arrest is analogous to that seen following human cardiac arrest. Administration of the competitive AMPA antagonist NBQX to rats resuscitated after 10 min duration cardiac arrest rescued 21.5% of the vulnerable Purkinje cell population. These results support the hypothesis that sustained postischemic overexcitation of AMPA receptors may be a driving force in the process of Purkinje cell degeneration.

Benzodiazepine receptor binding in cerebellar degenerations studied with positron emission tomography

We used positron emission tomography with [11C]flumazenil to study gamma-aminobutyric acid type A/benzodiazepine receptor binding quantitatively in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem of 72 subjects, including 14 with multiple system atrophy of the ataxic (olivopontocerebellar atrophy) type, 5 with multiple system atrophy of the extrapyramidal/autonomic (Shy-Drager syndrome) type, 18 with sporadic olivopontocerebellar atrophy, 15 with dominantly inherited olivopontocerebellar atrophy, and 20 normal control subjects with similar age and sex distributions. In comparison with data obtained from the normal control subjects, we found significantly decreased ligand influx in the cerebellum and brainstem of multiple system atrophy patients of the olivopontocerebellar atrophy type and in patients with sporadic olivopontocerebellar atrophy, but not in patients with multiple system atrophy of the Shy-Drager syndrome type. Despite these differences in ligand influx, benzodiazepine binding was largely preserved in the cerebral hemispheres, basal ganglia, thalamus, cerebellum, and brainstem in patients with multiple system atrophy of both types as well as those with sporadic or dominantly inherited olivopontocerebellar atrophy as compared with normal control subjects. The finding of relative preservation of benzodiazepine receptors indicates that these sites are available for pharmacological therapy in these disorders.

Clinical and magnetic resonance imaging study of extrapyramidal symptoms in multiple system atrophy

Slit-hyperintensity in the outer margin of the putamen on T2 weighted MRI was found in 17 out of 28 patients with clinically diagnosed multiple system atrophy. Thirteen of these 17 patients showed extrapyramidal signs. Five patients had only unilateral slit-hyperintensity; four of them had contralateral rigidity; and one had bradykinesia. Despite mild rigidity, one case showed no slit-hyperintensity. One of the 14 cases with parkinsonism showed no hyperintensity, and four of the 14 cases without parkinsonism showed hyperintensity. On the other hand, slit-hyperintensity was not seen in any of 25 patients with clinically diagnosed Parkinson's disease. Putaminal slit-hyperintensity is a useful MRI feature in the differential diagnosis between Parkinson's disease and multiple system atrophy predominantly affecting the extrapyramidal system.

A study of parkinsonism in multiple system atrophy: clinical and MRI correlation

We investigated clinical and MRI correlation in 18 patients with clinically-diagnosed multiple system atrophy (MSA) and 16 age-matched controls, using 1.5 T magnetic resonance imaging (MRI). We evaluated the severity of parkinsonism in each MSA patient. In assessing the MRI findings, we examined three parameters quantitatively: width of the pars compacta of the substantia nigra (SNc); putaminal hypointensity on T2-weighted images; and putaminal atrophy. As in previous studies, SNc width was narrowed and the putaminal signal intensity was decreased in patients with MSA compared with controls. The clinical severity of parkinsonism did not correlate significantly with the SNc width or the score of putaminal hypointensity in MSA. However, not only did putaminal atrophy occur, but correlated well with the severity of parkinsonism in MSA. A significant correlation could not be established between narrowing of SNc and shrinkage of the putamen. These findings suggest that putaminal atrophy is associated with the clinical manifestations of parkinsonism and do not support the hypothesis that transsynaptic degeneration occurs in MSA.

Patterns of cerebral glucose metabolism detected with positron emission tomography differ in multiple system atrophy and olivopontocerebellar atrophy

We used positron emission tomography with [18F]fluorodeoxyglucose to study local cerebral metabolic rates for glucose (ICMRglc) in patients with multiple system atrophy (MSA), sporadic olivopontocerebellar atrophy (sOPCA), and dominantly inherited olivopontocerebellar atrophy (dOPCA) in comparison with normal control subjects. IN MSA, absolute lCMRglc was significantly decreased in the brainstem, cerebellum, putamen, thalamus, and cerebral cortex. In sOPCA, absolute lCMRglc was significantly decreased in the brainstem, cerebellum, putamen, thalamus, and cerebral cortex. In dOPCA, absolute lCMRglc was significantly decreased in the brainstem and cerebellum but not in the other structures. Examination of lCMRglc normalized to the cerebral cortex in comparison with normal controls revealed in MSA significant decreases in the brainstem, cerebellum, and putamen but, in both sOPCA and dOPCA, significant decreases only in the brainstem and cerebellum. The findings indicate that these three disorders all show a marked decrease of lCMRglc in the brainstem and cerebellum but differ in the degree of hypometabolism in forebrain and cerebral cortical structures. The results are consistent with the possibility that, in many cases, sOPCA will evolve into MSA. Moreover, positron emission tomography may provide helpful diagnostic information in these neurodegenerative diseases.

Infantile multiple system atrophy with cytoplasmic and intranuclear glioneuronal inclusions

This report presents a case of infantile multiple system atrophy with probably autosomal recessive inheritance. The female patient developed generalized muscular hypotonia, myoclonias and tonic-clonic seizures at the age of 8 months, followed by gradual development of choreoathetotic hyperkinesia and increasing psychomotor retardation. Metabolic disease was ruled out and the child died of aspiration pneumonia at the age of 5 years. General autopsy was unremarkable, but neuropathological examination showed degeneration of cerebellum, inferior olives, medial thalamus, Clarke's nucleus, anterior horn cells, corticospinal, spinocerebellar tracts, and posterior columns. Immunohistochemically many neurons contained intranuclear and intracytoplasmic ubiquitin-positive inclusions, which did not contain neurofilament or tau epitopes and ultra-structurally consisted of granulofilamentous material. We tentatively classify this case as a form of infantile multiple system atrophy linked to neuronal intranuclear hyaline inclusion disease.

Neuronal cell loss of the striatonigral system in multiple system atrophy

We investigated the longitudinal as well as lateral loss of striatal and nigral cells and its distribution in 7 cases of multiple system atrophy. Loss of striatal small cells and nigral pigmented cells was more prominent in the caudal part than in the rostral and mid-parts. Cell loss was especially high in the dorsolateral zone of the caudal putamen and in the lateral zone of the caudal nigra. These findings indicate that MSA predominantly disturbs the striatal and nigral efferent systems, which interlink the caudal and dorsolateral putamen with the caudolateral nigra. In less severe cases, the rostral to mid-parts of the putamen or substantia nigra were almost intact while its caudal portion was clearly affected. The degenerative process of MSA seems to occur initially in the caudal parts of the putamen and substantia nigra, extending later to the rostral parts. Thus striatal small cells and nigral pigmented cells degenerate according to anatomical relationship. In MSA, degeneration of the striatonigral system could well be explained as being transsynaptic.