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[A comparative study of three cases of neuronal intranuclear inclusion disease (NIID)]
Saki Kotani1, Ryosuke Fukazawa1, Hidesato Takezawa1
1Department of Neurology, Saiseikai Shiga Hospital.
Abstract:
All three patients were men in their 70s. All cases were solitary onset and the chief complaint was gait disturbance. All patients had miosis and limb and trunk ataxia, MMSE score was declined in two patients, and FAB score was declined in all patients. Head MRI showed leukoencephalopathy, cerebellar atrophy, and DWI high intensity signal in corticomedullary junction. However, two of the three patients were not followed up without further examination. Skin biopsies in all cases showed ubiquitin-positive and p62-positive intranuclear inclusions. Genetic testing showed CGG repeat expansion of NOTCH2NLC. The diagnosis of neuronal intranuclear inclusion disease (NIID) was made based on the above findings in all cases. Most patients are diagnosed with NIID due to memory loss, but sometimes they are diagnosed due to gait disturbance with ataxia. It is important to proceed with the diagnosis by skin biopsy and genetic diagnosis based on the characteristic MRI findings of the head.
Insights
Neuronal intranuclear inclusion disease (NIID) can present with gait disturbance and ataxia. Diagnosis relies on characteristic MRI findings, skin biopsy, and genetic testing for NOTCH2NLC gene mutations.
Area of Science:
- Neurology
- Genetics
Background:
- Neuronal Intranuclear Inclusion Disease (NIID) is a rare neurodegenerative disorder.
- Early diagnosis is crucial for patient management and understanding disease progression.
Observation:
- Three male patients in their 70s presented with solitary onset gait disturbance, miosis, and ataxia.
- Cognitive decline was noted (MMSE in two, FAB in all).
- Head MRI revealed leukoencephalopathy, cerebellar atrophy, and specific DWI signals.
Findings:
- Skin biopsies confirmed ubiquitin-positive and p62-positive intranuclear inclusions.
- Genetic analysis identified CGG repeat expansion in the NOTCH2NLC gene.
- These findings led to a definitive diagnosis of NIID.
Implications:
- Gait disturbance can be an initial symptom of NIID, alongside cognitive decline.
- Skin biopsy and genetic testing are vital for confirming NIID, especially with characteristic MRI findings.
- This highlights the importance of a multi-faceted diagnostic approach for NIID.
