(Kiosk 1) Atypical Electrodiagnostic Findings in a Patient with Wernicke's Encephalopathy and Acute Onset Weakness: A Case Report

Case Diagnosis: Nutritional Deficiency in an otherwise healthy young male

Case Description or Program Description: Patient presented to Emergency Department for two weeks of progressive, symmetrical, peripheral weakness, falls, cognitive changes, vision disturbance and truncal ataxia. MRI brain demonstrated findings consistent with Wernicke’s Encephalopathy (WE). Labs were notable for Vitamin B1, B12, D and Copper deficiency. Myocardial Injury was seen with elevated troponins and proBNP. All findings were attributed to severe B1 (thiamine) deficiency. Patient denied alcohol use which was corroborated by family. Patient was provided high dose IV thiamine in acute care with improvement in vision, confusion, weakness and cardiac enzymes.

Setting: Outpatient Rehabilitation Hospital

Assessment/Results: On arrival to Inpatient rehabilitation, patient had resting tachycardia, nearly symmetric distal greater than proximal peripheral weakness, hyporeflexia and truncal ataxia. He was discharged home at wheelchair level with walker for short distances. Outpatient electrodiagnostic studies demonstrated findings of motor greater than sensory, axonal peripheral neuropathy. Needle electromyography showed abnormal spontaneous activity in distal greater than proximal lower extremity muscles accompanied by decreased recruitment, large units and some polyphasic units. Despite significant spontaneous activity/denervation of left biceps, triceps, pronator teres, the distal muscles in the hand were less affected. Left ulnar and median nerve conduction studies were normal and radial studies demonstrated reduced amplitudes. These findings argue against a purely length dependent process.

Discussion (relevance): Neuropathy related to thiamine deficiency typically presents with length dependent, symmetrical, sensory equal to motor changes. Here, there was much greater motor than sensory involvement as well as evidence against a purely length dependent process. This may be more suggestive of a secondary process or a deviation from our historical understanding of neuropathy related nutritional deficiencies.

Conclusions: This case demonstrates atypical nerve conduction findings in a patient with thiamine deficiency. These findings may be consistent with a concomitant, acute axonal peripheral neuropathy. Follow up electrodiagnostic studies are to follow