Somatic sprouts of the Purkinje cells in a patient with multiple system atrophy

We describe the post mortem case of a 71-year-old Japanese woman diagnosed as having multiple system atrophy (MSA), showing somatic sprouting formation of Purkinje cells. The patient had suffered from frequent falling episodes and clumsiness of the left hand since the age of 67 years. Orthostatic hypotension and parkinsonism subsequently emerged. Typical neuropathological features of MSA, including degeneration of the striatum, pontine base and cerebellum with abundance of phosphorylated α-synuclein-positive neuronal and glial cytoplasmic and nuclear inclusions in the brain, were observed. In addition to gliosis of the cerebellar white matter and notable loss of Purkinje cells, several Purkinje cells showed somatic sprouting. Somatic sprouting of Purkinje cells has been demonstrated in several specific conditions, such as developing brains and several neurodegenerative disorders, including Menkes kinky hair disease, familial spinocerebellar ataxia, acute encephalopathy linked to familial hemiplegic migraine, and Huntington's disease; however, no MSA cases have been reported with sprouting from the soma of Purkinje cells. Axonal damage caused by oligodendroglial dysfunction could be crucial in the development of Purkinje cell loss in MSA. Moreover, no apparent α-synuclein accumulation has been described in the Purkinje cells of MSA. We propose that MSA is another degenerative disorder associated with somatic sprouts of Purkinje cells.