Student University of New England College of Osteopathic Medicine Topsham, Maine
Case Diagnosis: Mononeuritis Multiplex Secondary to Nutritional Deficiency
Case Description: A female patient in her early thirties with a BMI over 50, presents to the emergency department complaining of paresthesia in bilateral upper and lower extremities that have worsened over 2-3 weeks. She has increasing falls and difficulty managing IADL’s. She is following a ketogenic diet to lose weight, endorsing an 80-pound weight loss in 2 months. Physical exam shows diffuse bilateral lower extremity weakness with sporadic deficits in pain sensation, but normal DTRs, proprioception, and vibratory senses. Upper extremity exam reveals diffuse bilateral weakness with sparing of the deltoid, and normal DTRs, proprioception, and sensation. Cranial nerves are fully intact. MRI Brain and Spine, Lumbar Puncture, ANA, CRP, Rheumatoid Factor, Vitamin B12, heavy metals, and tickborne panels are all grossly normal; Vitamin B1 is severely deficient.
Discussion: While a ketogenic diet has potential benefits for weight loss, diabetes management, and epilepsy, it has been documented to rarely lead to optic neuropathy and Wernicke’s Encephalopathy. These outcomes are postulated to be correlated with Vitamin B1 (thiamine) deficiency in patients with extreme caloric deficits. As seen in this patient, extreme dietary restriction, lack of supplementation, and absence of physician supervision have led to deleterious neurologic effects in the setting of thiamine deficiency.
Assessment/Results: This patient was diagnosed with mononeuritis multiplex secondary to nutritional deficiency from her extreme caloric deficit following a ketogenic diet. After thiamine infusions and twenty days of inpatient rehabilitation, she was discharged and has regular follow-up visits with her physiatrist. She has continued to show improvement in strength but requires bilateral ankle foot orthoses and a cane for long distances and suffers from neuropathic pain in bilateral lower extremities.
Conclusion: In patients presenting with unusual etiologies for neurologic damage, consider nutrient deficiency especially in the setting of new dietary changes.
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