Utility of Dissociated Intrinsic Hand Muscle Atrophy in the Diagnosis of Amyotrophic Lateral Sclerosis

Dissociated atrophy of intrinsic hand muscles, termed the split hand, appears to be a specific feature of amyotrophic lateral sclerosis (ALS). Consequently, a novel neurodiagnostic test, termed the split hand index, was developed to quantify the clinical phenomenon of the split hand, which differentiated ALS from mimic disorders.