Pelizaeus-Merzbacher disease (PMD) is a X-linked recessive disorder with dysmyelination in central nervous system caused by proteolipid protein 1 (PLP1) gene mutation. We report a case of PMD with PLP1 exon 1 duplication, previously misdiagnosed as cerebral palsy (CP).A 25-year-old male previously diagnosed as CP visited our clinic with progressive weakness and spasticity of bilateral lower limbs. Next generation sequencing revealed hemizygous duplication of exon 1 in PLP1. Additionally, multiplex ligation-dependent probe amplification assay of the patient's mother showed the same mutation, which could finally confirm the diagnosis as PMD. This patient received comprehensive rehabilitation program, and helped the patient to achieve functional improvement. Proper diagnosis and therapeutic plan will be needed for the patients with PMD, before diagnosing CP rashly.

Benign monomelic amyotrophy (BMA) is a benign motor neuron disease in which amyotrophic change is confined to either the upper or the lower extremities. Numerous cases of BMA have been reported from Japan and India. However, only a few cases have been reported from other regions, including South Korea. Here we report a rare case of late-onset BMA in Korean male using conventional diagnostic approach with magnetic resonance imaging and electromyography. The patient received ten sessions of manual therapy, which focused on strengthening of the left ankle. At two-month follow up, weakness was still isolated to the patient’s left ankle. There were no signs of disease progression.

Benign monomelic amyotrophy (BMA) is a benign motor neuron disease in which amyotrophic change is confined to either the upper or the lower extremities. Numerous cases of BMA have been reported from Japan and India. However, only a few cases have been reported from other regions, including South Korea. Here we report a rare case of late-onset BMA in Korean male using conventional diagnostic approach with magnetic resonance imaging and electromyography. The patient received ten sessions of manual therapy, which focused on strengthening of the left ankle. At two-month follow up, weakness was still isolated to the patient’s left ankle. There were no signs of disease progression.