A 50-year-old woman complains of clumsiness in her hands while working in the kitchen: She recently burned her hands on the stove without experiencing any pain. Neurologic examination reveals bilateral weakness of the shoulder girdles, arms, and hands as well as a loss of pain and temperature sensation covering the shoulder and upper limb in a cape-like distribution. Severe atrophy is present in the intrinsic muscles of the hands. The most likely diagnosis is:

Syringomyelia: cavitation of the spinal cord seen in the cervicothoracic segments. This results in b/L loss of pain and temperature sensation in a cape-like distribution as well as wasting of the intrinsic muscles of the hands. Sensory deficit is directed from proximal to distal pas. ALS is a pure motor syndrome Subacute combined degeneration includes both sensory and motor deficits Werdnig-Hoffmann disease is a pure motor disease Tabes dorsalis is a pure sensory syndrome (neurosyphilis).