Neuronal Intranuclear Inclusion Disease

**Semantic type:** Disease or Syndrome

**Definition:** A rare, slowly progressive, multisystem neurodegenerative disorder that usually affects children. It is characterized by the presence of eosinophilic neuronal intranuclear inclusions and neuronal loss. It results in abnormalities of the central, peripheral, and autonomic nervous systems. Patients present with ataxia, extra-pyramidal signs, absent deep tendon reflexes, weakness, muscle wasting, foot deformities, and behavioral or cognitive abnormalities.

**Synonyms:** - NIID