Juvenile parkinsonism (onset age <20 yrs) is uncommon and few cases with neuropathologic confirmation have been reported. We present the case of a 17-year-old boy who presented with asymmetric arm
tremor and bulbar symptoms. His paternal great aunt had
parkinsonism with onset at age 22 years. Examination revealed
parkinsonism in the absence of additional
neurologic signs except for delayed pupillary responses to light. He responded well to
levodopa but developed motor fluctuations and disabling
dyskinesias after 3 years of treatment. Following attempted withdrawal of
levodopa at age 24 years, he developed severe
aspiration pneumonia complicated by cardiorepiratory arrests and he died 6 months later. At autopsy, the dominant histologic feature was wide-spread neuronal hyaline intranuclear inclusions. Neuronal depletion was observed in the substantia nigra, locus ceruleus, and, to a lesser extent, in the frontal cortex, and inclusions were particularly prominent in these areas. Inclusions were immunoreactive for
ubiquitin and were typical of those seen in
neuronal intranuclear inclusion disease (NIID), a rare, multisytem
neurodegenerative disease. NIID should be considered in the differential diagnosis of
juvenile parkinsonism. A link between NIID and hereditary
neurodegenerative disorders characterized by expanded
polyglutamine tracts is supported by the similar appearance of intranuclear inclusions in both conditions and by a family history in some cases of NIID.