Proximal arm weakness is the most common presentation in young Korean soldiers diagnosed as having hereditary neuropathy with liability to pressure palsy (HNPP)

Prevalence of Neuromuscular Diseases in Young South Korean Males; A Korean Military Manpower Administration and Medical Command Data-Based Study

BACKGROUND AND PURPOSE

All young males in South Korea must undergo a physical examination for their participation in military service. We aimed to determine the prevalence rate (PR) of various neuromuscular diseases in young South Korean males using the data of exempted patients and soldiers.

METHODS

The number of males exempted based on specific items of physical examination corresponding to neuromuscular disease during 2011-2020 were obtained from the records of the Military Manpower Administration. The list of enlisted soldier patients who were discharged from military service due to neuromuscular diseases during 2011-2020 was obtained from the Armed Forces Medical Command, and their medical records were reviewed.

RESULTS

The PR of neuromuscular diseases was calculated among 948 identified males: 713 exempted males and 235 soldiers. The PRs of overall hereditary neuropathies, Hirayama disease (HD), myasthenia gravis (MG), and inherited muscle diseases in South Korean males in their early 20s were 8.34 (95% confidence interval [CI], 7.39-9.30), 5.54 (95% CI, 4.76-6.32), 2.97 (95% CI, 2.40-3.55), and 10.38 (95% CI, 9.31-11.46) per 100,000 persons, respectively. Among the enlisted soldiers, hereditary neuropathy with liability to pressure palsy was the most common neuromuscular disease, with a prevalence among the enlisted soldiers of 3.11 (95% CI, 2.42-3.80) per 100,000 persons. Myotonic dystrophy was the most prevalent myopathy, followed by facioscapulohumeral muscular dystrophy.

CONCLUSIONS

The 10-year PRs of hereditary polyneuropathies, HD, MG, and inherited muscle diseases in young South Korean males have been reported. These data could be valuable to understanding each neuromuscular disease in the young male population of South Korea.

Clinical characteristics of hereditary neuropathy with liability to pressure palsy presenting with monoparesis in the emergency department

Hereditary neuropathy with liability to pressure palsy (HNPP) is a rare neurological genetic disease caused by deletion of the peripheral myelin protein 22 gene and presents in childhood or young adulthood. We report four cases of HNPP with typical and rare presentations, reflecting the broad clinical spectrum of this disease. Two patients presented with mononeuropathies that are frequently observed in HNPP; the remaining two presented with bilateral neuropathy or mononeuropathy anatomically present in the deep layer. This reflects the broad clinical presentation of HNPP, and clinicians should differentiate these conditions in young patients with monoparesis or bilateral paresis. Although HNPP is currently untreatable, early diagnosis in the emergency department can lead to early detection, eventually resulting in less provocation and recurrence which may cause early motor nerve degeneration.

Clinical, electrophysiological, genetic, and imaging features of six Chinese Han patients with hereditary neuropathy with liability to pressure palsies (HNPP)

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant peripheral neuropathy caused by mutations in the peripheral myelin protein 22 (PMP22) gene. This study summarizes the clinical, electrophysiological, genetic, and imaging features of six unrelated Chinese Han patients with HNPP. Age of onset was within the second decade in five patients, and 46 years of age in one patient. Weakness or numbness in a unilateral lower extremity was the most common symptom in 5 patients, and bilateral sensorineural hearing loss was also detected in one patient. Electrophysiological presentations suggested demyelinating sensory-motor polyneuropathy in the group. Magnetic resonance imaging (MRI) of the cervical and lumbar spine revealed varying degrees of degeneration in five patients, and mild kyphosis of cervical vertebral bodies in 2 teen-aged patients. In addition, cranial MRI of one patient showed scattered demyelination in the frontal lobes. Targeted next-generation-sequencing (NGS) revealed a PMP22 deletion in five patients and a heterozygous c.199G>A mutation in exon 4 of PMP22 in one patient. The I92V variant of lipopolysaccharide-induced tumor necrosis factor (LITAF) gene was found in one patient. There was no relationship between the Ile92Val variant of LITAF and age of onset in this group, albeit the sample size was very small.