RÉSUMÉ
Objective:To summarize the electrophysiological characteristics of neuronal intranuclear inclusion disease (NIID) and explore the value of electrophysiological examination in NIID auxiliary diagnosis.Methods:Twenty NIID patients diagnosed by pathological biopsy and genetic confirmation (15 were symptomatic, 5 were asymptomatic), admitted to Department of Neurology, Affiliated Hospital of Xuzhou Medical University from February 2020 to June 2022 were chosen. Peripheral motor/sensory nerve conduction, needle electromyography, F wave, repetitive electrical stimulation, skin sympathetic reflex (SSR), and tremor were analyzed. Peripheral nerve conduction and SSR parameters were compared between 15 patients with symptomatic NIID (symptomatic NIID group) and 11 age- and gender-matched normal control subjects (control group).Results:(1) All 15 patients with symptomatic NIID were with abnormal electrophysiological findings: 14 patients had abnormal peripheral nerve conduction, including 14 with slowed motor nerve conduction velocity (MCV), 4 with reduced composite muscle action potential (cMAP) wave amplitude, 12 with slowed sensory nerve conduction velocity (SCV), and 3 with reduced sensory nerve action potential (sNAP) wave amplitude, and overall slowed nerve conduction velocity and relatively preserved wave amplitude were noted; 4 patients had neurogenic lesions by needle electromyography; 13 patients had prolonged F-wave latency at varied degrees; 12 showed abnormal SSR; 4 exhibited synchronous tremor from 4.0 to 7.5 Hz. (2) In 5 patients with asymptomatic NIID, 3 had abnormal peripheral nerve conduction, including 3 with slowed MCV, 2 with slowed SCV, and 1 with reduced sNAP wave amplitude; 3 showed abnormal SSR. (3) Significant differences in MCV and SCV, some cMAP and sNAP amplitudes, and SSR latency and amplitude were noted in nerves of the upper and lower extremities between the symptomatic NIID group and control group ( P<0.05). Conclusion:Peripheral nerve damages are common in patients with NIID, especially myelin damage and autonomic nerve injury, and some patients may have electrophysiological abnormalities before clinical symptoms; therefore, peripheral nerve conduction and SSR can be recommended as auxiliary screening tools for NIID.