Copper deficiency myeloneuropathy (CDM) is a rare but well-described complication of bariatric surgery characterized by profound gait impairment, sensory ataxia, spastic para/tetraparesis, and a sensorimotor polyneuropathy.  “Burning Foot Syndrome” (BFS) is a well-known symptom of starvation but previously has only been associated with thiamine deficiency.

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CASE REPORT: 52-year-old female with a history of morbid obesity s/p Roux-en-Y gastric bypass six months prior presented to our emergency department with four weeks of progressive gait instability, leg weakness, and paresthesias.  At presentation, she was unable to ambulate and had unbearable bilateral foot pain.  Neurologic exam was notable for gaze-evoked nystagmus, symmetric paraplegia, diffuse hyperreflexia, dysdiadochokinesia, and profound truncal ataxia with gait instability.  Initial labs were notable for a macrocytosis, mild transaminitis, normal B12/folate, and low serum ceruloplasmin.  MRIs of the brain and spinal cord were unremarkable.  EMG/NCS demonstrated a length-dependent axonal sensorimotor polyneuropathy.  After nutritional labs were drawn, empiric treatment for a presumed nutritional neuropathy was started with IV thiamine, oral elemental copper, and oral vitamin D. Laboratory evaluation subsequently returned with a low serum/urine copper and elevated urine zinc.  A diagnosis of copper deficiency myeloneuropathy was made and therapy was tailored accordingly.  After one month, the patient made a dramatic recovery with near normalization of her neurologic exam.  However, her BFS remained and was refractory to oral gabapentin and topical capsaicin cream.  Her symptoms were successfully controlled with 8% topical capsaicin patches (Qutenza) every 3 months.

Copper deficiency is a rare complication of bariatric surgery that usually occurs many years after surgery, but can occur acutely.  With prompt recognition and treatment, profound neurologic disability can be prevented.  “Burning foot syndrome” is a disabling symptom that has previously been associated only with thiamine deficiency.  To our knowledge, this is the first reported case of BFS with copper deficiency.