P62 STAINING INCLUSIONS IN AN MSA-P PHENOTYPE: A NEW NEURODEGENERATIVE ENTITY?

Background We report a case of a middle aged lady who presented with sub- acute and progressive neurological symptoms, with death within 2 years of onset of symptoms. Initial presentation was 9 months of asymmetrical postural tremor rapidly progressing to gait disturbance, dysarthria, dysautonomia, and respiratory stridor. Clinical diagnosis was MSA-P. Methods Clinical case description. Results Autonomic function tests abnormal. DAT showed symmetrical reduction in putaminal uptake although dopa challenge was negative. Cerebral SPECT revealed reduced perfusion to the frontal lobes and temporal lobes. MRI showed mild fronto-temporal atrophy with iron deposition in putamina. Huntington's genetics was negative. Subsequent post-mortem exam showed striking atrophy of basal ganglia and cingulate gyrus. Severe neuronal loss in substantia nigra was noted. White matter tracts adjacent to thalamus and basal ganglia were involved. Extensive p62 staining of coil bodies resembling glial cytoplasmic inclusions was seen. These were specifically negative for synuclein. Immunostaining for tau and TDP-43 was negative. Conclusion This rapidly progressive case of parkinsonism had an MSA-P phenotype but subsequent pathological exam showed no evidence of a synucleinopathy. P62 protein is involved in the ubiquitin pathway and has been demonstrated in ALS/FTD cases and PD cases. This is the first description to our knowledge in an MSA phenocopy.