Analysis of clinical, electromyographic characteristics in tremor patients with neuronal intranuclear inclusion disease / 中华神经科杂志

ABSTRACT

Objective:To analyze the clinical, electromyographic and tremor characteristics in tremor patients with neuronal intranuclear inclusion disease (NIID).Methods:From May 2018 to April 2023, 34 patients with NIID diagnosed in the Department of Neurology, Beijing Tiantan Hospital of Capital Medical University were retrospectively included. Sixteen patients with tremor of at least one limb and (or) head were in tremor group, and 18 patients without tremor were in control group. The clinical, electromyogram and tremor data of all participants were summarized, the clinical features and electromyogram differences of the 2 groups were compared, and the tremor characteristics of patients with NIID were analyzed.Results:The proportion of female patients in the tremor group was higher than that in the non tremor group (12/16 vs 7/18, P=0.045). The proportion of upper and lower limb peripheral nerve damage in the tremor group was lower than that in the non tremor group (2/16 vs 9/18, P=0.030), with statistical significance. There was no significant difference between the 2 groups in higher cortex and autonomic nervous dysfunction. The amplitude of composite muscle action potential and sensory nerve action potential in all patients was normal or slightly decreased; some patients experienced a decrease in motor and sensory fiber conduction velocity. The proportion of motor and sensory nerve conduction velocity slowing in the non tremor group was higher than that in the tremor group [motor nerve:41.7%(30/72) vs 17.2%(11/64), χ 2=9.64, P=0.002;sensory nerve:38.9% (35/90) vs 20.0%(16/80), χ 2=7.19, P=0.007]. The number of cases of postural tremors in different parts among the 16 patients was as follows: 13 in the upper limbs, 7 in the lower limbs, and 6 in the head; static tremor: 8 cases in the upper limbs, 3 cases in the lower limbs, and 5 cases in the head. At rest, the frequency of tremors in different parts of the body was as follows: upper limb (5.3±1.1) Hz, lower limb (4.2±0.4) Hz, and head (3.9±0.6) Hz. The difference in tremor frequency among the 3 parts was statistically significant ( F=3.92, P=0.047); Pairwise comparison showed that the frequency of head tremor was lower than that of upper limb tremor, with a statistically significant difference ( P=0.020). In a postural state, tremor frequency in different parts was as follows: upper limb (5.4±0.9) Hz, lower limb (5.0±0.7) Hz, head (3.9±0.7) Hz. There was a statistically significant difference in tremor frequency among the 3 parts ( F=6.65, P=0.005). Further pairwise comparison revealed statistically significant differences in tremor frequency between the patient′s head, upper and lower limbs ( P=0.001, P=0.022). Synchronous tremor rhythm was predominant, with occasional alternations or synchronous+alternations. There was no harmonic tremor spectrum was observed. Conclusions:NIID patients with tremors were more common in female patients.The degree of peripheral nerve damage was milder than those without tremors. The site and form of tremor were diverse, with a dominant frequency of 4-6 Hz, mainly synchronous rhythm, and no harmonic spectrum. Postural tremors were common in the limbs.