Neuronal intranuclear inclusion disease: report on a case originally diagnosed as dopa-responsive dystonia with Lewy bodies.

Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder with a heterogeneous clinical picture characterized by the presence of eosinophilic intranuclear inclusions in neuronal and glial cells. We describe a case, reported 12 years ago as dopa-responsive dystonia (DRD) with Lewy body pathology. Pathological re-examination has led to a revised diagnosis of neuronal intranuclear inclusion disease. This rare condition, which may be diagnosed in life with a full thickness rectal biopsy, needs to be considered in the differential diagnosis of any case presenting as progressive juvenile parkinsonism (JP) or dystonia.