Cervical Spondylotic Amyotrophy Initially Misdiagnosed as Amyotrophic Lateral Sclerosis.

A 63-year-old man diagnosed with mixed-type cervical spondylotic amyotrophy exhibited severe atrophy in the right biceps brachii, teres major, and intrinsic hand muscles, resulting in level 3 muscle weakness. Magnetic resonance imaging showed symmetrical high signal, also referred to as the snake eye sign. Previously, he was erroneously diagnosed with amyotrophic lateral sclerosis. He had undergone anterior cervical surgery 7 years prior. At present, his right upper limb muscles display minimal atrophy compared with the left, with muscle strength nearing level 4, which is considered normal. We believe that prompt surgical intervention on diagnosis of cervical spondylotic amyotrophy, along with comprehensive postsurgery rehabilitation, can halt further deterioration of the condition and accelerate recovery.