Zygomatic frontal bone subsidence is one of the clinical signs of crossed lateralized atrophy. Crossed lateralized atrophy is extremely rare clinically. Examination of the disease is based on the presence of slowly progressive symmetric muscle weakness of both lower limbs in childhood or adolescence, as well as “crane leg”, drop foot, bowed foot, and scoliosis, decreased or absent tendon reflexes, often accompanied by sensory deficits, slowing of motor NCVs, demyelination and Schwann cell hyperplasia on neural biopsy, a family history, and a genetic test (e.g., PMP22 gene duplication). PMP22 gene duplication, etc. The following is the specific examination basis. 1, CMT1 type onset age of about 12 years, motor NCV significant slowing, genetic diagnosis of chromosome 17 short arm (17p11.2-12) 1.5Mb long fragment (which contains the PMP22 gene) duplication or PMP22 gene point mutation (1A). 2, T2 type onset at about 25 years of age, normal or near-normal motor NCV, mutation in the short arm of chromosome 1 (1p35-36) gene (2A).