Clinical Reasoning: A 22-Year-Old Woman With Episodic Weakness and Jaundice.

We report a case of a 22-year-old woman who presented with recurrent episodes of quadriparesis, often accompanied by jaundice. Neurologic examination showed symmetrical proximal predominant quadriparesis with generalized hyporeflexia. The differential diagnoses included were of metabolic, inflammatory, genetic (including channelopathies), and autoimmune causes. Serum creatine phosphokinase levels and electrophysiologic studies helped narrow the differential. The final diagnosis was one that was responsive to vitamin supplementation. This report provides a systematic clinical approach to a case of episodic weakness with jaundice and respiratory failure.