Establishing the Law of Parsimony in a Case of Restless Legs Syndrome

Restless legs syndrome (RLS) is a common movement disorder characterized by uncomfortable sensations in the lower limbs relieved by limb movements. Clinical studies have established a possible association between RLS and vitamin B12 deficiency but not a causal one. RLS has rarely been reported as an isolated neurological manifestation of vitamin B12 deficiency. In this case report, we described a 24-year-old young man with RLS who responded poorly to symptomatic therapy. The etiological evaluation suggested vitamin B12 deficiency secondary to pernicious anemia. The patient responded rapidly to vitamin B12 supplementation and clinical manifestations of RLS resolved, suggesting a possible causal relationship.