Makoto Nishie

Accumulation of phosphorylated α-synuclein in the brain and peripheral ganglia of patients with multiple system atrophy

We immunohistochemically examined the brain and peripheral sympathetic ganglia from eight patients with multiple system atrophy (MSA), using an antibody specific for phosphorylated α-synuclein (anti-PSer129). Phosphorylated α-synuclein was deposited in five cellular locations: oligodendroglial cytoplasm and nucleus, and neuronal cytoplasm, processes and nucleus. Many neuronal cytoplasmic inclusions (NCIs) were found in the pontine and inferior olivary nuclei and, to a lesser extent, in the substantia nigra, locus ceruleus, and neocortical and hippocampal neurons. NCIs were also found in the sympathetic ganglia in two out of the eight cases. Moreover, anti-PSer129 immunohistochemistry revealed extensive neuropil pathology; swollen neurites were abundant in the pontine nucleus, delicate neurites were observed in the deeper layers of the cerebral cortex and thalamus, and neuropil threads and dot-like structures were distributed in the basal ganglia and brainstem. Diffuse neuronal cytoplasmic staining (pre-NCI) was frequently found in the pontine and inferior olivary nuclei. Thus, the widespread accumulation of phosphorylated α-synuclein in both glial and neuronal cells is a pathological feature in patients suffering from MSA.

Accumulation of NEDD8 in neuronal and glial inclusions of neurodegenerative disorders

NEDD8 (neural precursor cell expressed, developmentally down‐regulated 8) is a ubiquitin‐like protein that controls vital biological events through its conjugation to members of the cullin family, which are components of certain ubiquitin E3  ligases.  Recent  studies  have  shown  that  NEDD8 is incorporated into Lewy bodies (LBs) in Parkinsons disease, Mallory bodies in alcoholic liver disease and Rosenthal fibres in astrocytoma. In order to examine whether NEDD8 plays a role in the formation of ubiquitinated inclusions, we performed immunohistochemical staining of brain tissue from patients with various neurodegenerative disorders, using an affinity‐purified polyclonal antibody raised against NEDD8 that did not cross‐react with ubiquitin. In LB disease, NEDD8 immunoreactivity was present in almost all of the LBs and Lewy neurites. Moreover, NEDD8 immunoreactivity was found in a variety of ubiquitinated inclusions, including neuronal and oligodendroglial inclusions in multiple system atrophy, neurofibrillary tangles in Alzheimers disease, ubiquitinated inclusions in motor neurone disease, and intranuclear inclusions in triplet repeat diseases. These findings suggest that NEDD8 is involved in the formation of various ubiquitinated inclusions via the ubiquitin‐proteasome system.

A quantitative investigation of neuronal cytoplasmic and intranuclear inclusions in the pontine and inferior olivary nuclei in multiple system atrophy

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease characterized by the presence of neuronal and oligodendroglial α‐synuclein aggregates. To investigate the relationship between the occurrence of neuronal cytoplasmic and intranuclear inclusions (NCIs and NNIs, respectively) and the progression of neuronal degeneration, we performed a quantitative analysis of the pontine and inferior olivary nuclei based on 14 cases of MSA. α‐Synuclein immunohistochemistry revealed that NCIs and NNIs were present in both brain nuclei in all the cases. The average incidence of NCIs in the pontine and inferior olivary nuclei was 9.1% and 25.8%, respectively, and that of NNIs was 9.2% and 9.0%, respectively. The number of NNIs was strongly correlated with that of neurones in the pontine and inferior olivary nuclei. Although the number of NCIs was not correlated with the neuronal population in both nuclei, the NCI count in patients with moderate MSA was higher than in patients with mild MSA. The NNI count was much higher than the NCI count in the pontine nucleus in four patients, and was the same in the olivary nucleus in three of the four patients. Moreover, the neuronal population in the NNI‐predominant cases was significantly higher than in the NCI‐predominant cases. These findings suggest that NCI formation is accelerated by the progression of the disease process, and that in MSA, NNI formation is an earlier phenomenon than NCI formation.

Relationship Among α-Synuclein Accumulation, Dopamine Synthesis, and Neurodegeneration in Parkinson Disease Substantia Nigra

Abstract The histologic hallmark of Parkinson disease (PD) is loss of pigmented neurons in the substantia nigra (SN) and locus ceruleus (LC) with accumulation of &agr;-synuclein (&agr;S). It has been reported that tyrosine hydroxylase (TH)-negative pigmented neurons are present in these nuclei of patients with PD. However, the relationship between TH immunoreactivity and &agr;S accumulation remains uncertain. We immunohistochemically examined the SN and LC from patients with PD (n = 10) and control subjects (n = 7). A correlation study indicated a close relationship among decreased TH immunoreactivity, &agr;S accumulation, and neuronal loss. In addition, 10% of pigmented neurons in the SN and 54.9% of those in the LC contained abnormal &agr;S aggregates. Moreover, 82.3% of pigmented neurons bearing &agr;S aggregates in the SN and 39.2% of those in the LC lacked TH immunoreactivity, suggesting that pigmented neurons in the SN have a greater tendency to lack TH activity than those in the LC. Recent studies have shown that this decrease of TH activity leads to a decrease of cytotoxic substances and that decreased dopamine synthesis leads to a reduction of cytotoxic &agr;S oligomers. Therefore, the decrease of TH immunoreactivity in pigmented neurons demonstrated here can be considered to represent a cytoprotective mechanism in PD.

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. α-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 α-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, α-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).

Hypoglycemic encephalopathy with extensive lesions in the cerebral white matter

Here we report an autopsy case of hypoglycemic encephalopathy with prolonged coma. Laboratory data obtained when the patient lapsed into a coma showed that she had a low level of serum glucose (27 mg/dL). Although the level of glucose returned to within the normal range rapidly after glucose infusion, the patient remained in a coma for 22 months. It was presumed that the state of hypoglycemia persisted for about 4 h. There was no evidence of hypotension or hypoxia. Magnetic resonance imaging was performed 3 h after glucose administration; diffusion‐weighted images revealed hyperintensity in the cerebral white matter and in the boundary zone between the middle and posterior cerebral arteries. Post‐mortem examination revealed superficial laminar necrosis throughout the cerebral cortex. Neuronal necrosis was also found in the hippocampus and dentate gyrus, although the CA3 region appeared normal. In addition to these lesions, which are consistent with hypoglycemia‐induced brain damage, the cerebral white matter exhibited severe loss of myelin and axons with reactive astrocytosis and macrophage infiltration. Old infarcts were also present in the bilateral occipital lobes. Since the cerebral blood flow is reported to be decreased during severe hypoglycemia, the present findings suggest that white matter lesions and boundary‐zone infarctions may develop primarily in uncomplicated hypoglycemia.

Anti-Hu associated paraneoplastic sensory neuronopathy with upper motor neurone involvement

Paraneoplastic neurological syndrome is characterised by neuronal degeneration with lymphocytic infiltration in various regions of the central and peripheral nervous systems. Motor neurone symptoms may occur as a remote effect of malignancy, and have been considered because of the involvement of lower motor neurones. A case is reported of an 80 year old woman suffering from paraneoplastic sensory neuronopathy with anti-Hu antibody. Postmortem examination showed adenocarcinoma of the gall bladder and small cell carcinoma of the duodenum. Neuronal loss with lymphocytic infiltration was found in the dorsal root ganglia, brain stem, and cerebellum. Despite the absence of upper motor neurone signs, there was severe loss of Betz cells and degeneration of the bilateral pyramidal tracts. To our knowledge, this is the first demonstration of upper motor neurone involvement in anti-Hu associated paraneoplatic syndrome.

Multinucleated astrocytes in old demyelinated plaques in a patient with multiple sclerosis

A 51‐year‐old woman with MS of 26 years duration is reported. The patients MS history began at the age of 25 years with an initial relapsing‐remitting course, followed by slow progression without distinct relapses. She became bed‐ridden at the age of 40 years. A post‐mortem examination revealed numerous demyelinated plaques that exhibited fibrillary gliosis with Rosenthal fibers, but without lymphocytic cuffing or foamy macrophages. Activated microglia were found mainly in the marginal portion of the plaques. These plaques were consistent with so‐called ‘slowly expanding plaques’. Interestingly, multinucleated astrocytes were observed within the plaques, being more numerous in the area where microglial infiltration had occurred. These findings suggest that mild persistent inflammatory processes are present even in old plaques and that certain inflammatory stimuli cause multinucleation of astrocytes. This might explain the gradual deterioration without definite relapses observed in the late stage of MS.

Oligodendrocytes within astrocytes (“emperipolesis”) in the cerebral white matter in hepatic and hypoglycemic encephalopathy

We report the occurrence of oligodendrocytes within astrocytes (“emperipolesis”) in two autopsy cases of metabolic encephalopathy: one patient with hepatic encephalopathy due to citrullinemia who suffered recurrent unconsciousness (clinical duration, 32 months) and another with hypoglycemic encephalopathy who lapsed into a persistent vegetative state (clinical duration, 22 months). In both cases, hypertrophic astrocytes were found to have engulfed one to several oligodendrocytes in the devastated cerebral white matter. Previous studies have reported that emperipolesis occurs in various CNS diseases showing destruction of myelin or inflammation of the white matter, including multiple sclerosis, cerebral infarct and CJD. The present findings suggest that emperipolesis can occur even in chronic metabolic disorders that extensively involve the cerebral white matter.

Disseminated intraparenchymal microgranulomas in the brainstem in central nervous system sarcoidosis

We report a 70‐year‐old woman with sarcoidosis and multiple cranial nerve palsy. The patient suffered from dysarthria, dysphagia and weakness of the upper and lower extremities and died of sepsis. No abnormalities were noted in brain MRI. At autopsy, numerous epithelioid granulomas with Langhans giant cells were present in the bilateral lungs, including the hilar lymph nodes. The brain had a normal external appearance. Histologically, there were brainstem parenchymal lesions consisting of many microgranulomas, lymphocytic infiltration, activated microglias and astrocytosis. Perivascular lympocytic cuffing was also seen. Neither granulomas nor lymphocytic infiltration were seen in the leptomeninges. The present case was considered to be a peculiar type of neurosarcoidosis, that is, “sarcoid brainstem encephalitis”.