Proximal sensory neuropathy and cerebellar ataxia as presenting symptoms of NOTCH2NLC-related neuronal intranuclear inclusion disease

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by the presence of eosinophilic hyaline intranuclear inclusions [1]. CGG repeat expansions in NOTCH2NLC are present in Asian patients [2–5]. Sporadic late-onset cases most often present with cognitive decline. Subclinical peripheral neuropathies are common in sporadic late-onset patients, often identified through nerve conduction studies [1,4,5]. While patients with familial young-onset NIID reported motor-dominant neuropathy leading to muscle weakness [1,4–6], whether sensory symptoms can also be the chief and presenting symptom remains uncertain.