Disclosures: Justin X. Tu, MD: No financial relationships or conflicts of interest

Case Description: The patient presented to cancer rehabilitation clinic with a 3-month history of right shin and dorsal foot numbness, right foot drop, and balance impairment. She had been diagnosed with lymphoma 6 months earlier. She was undergoing chemotherapy and notably reported having lost 40-50 lbs since diagnosis. Physical examination was notable for 0/5 strength with right ankle dorsiflexion and big toe extension, as well as decreased sensation in the web space between the right first and second toes. Given her new foot drop, she was prescribed an AFO and referred for electrodiagnostic testing.

Setting: Outpatient cancer rehabilitation clinic.

Patient: A 73-year old female with gastric high-grade B Cell Lymphoma. Assessment/

Results: Nerve conduction studies showed focal conduction slowing and partial conduction block of the right fibular nerve across the fibular head. There were reduced fibular compound muscle action potentials at the right tibialis anterior and extensor digitorum brevis muscles. On electromyography, fibrillation potentials were noted in the right tibialis anterior, peroneus longus, and extensor hallucis brevis muscles, suggestive of sub-acute denervation. Enlarged motor unit action potentials were seen in the right tibialis anterior and peroneus longus muscles. These findings are diagnostic of an incomplete common fibular neuropathy localizing to the fibular head, consistent with slimmer’s palsy.

Discussion: Slimmer’s palsy has been associated with cases of weight loss, typically in the setting of dieting or bariatric surgery. This neuropathy is attributed to increased susceptibility to mechanical irritation at the proximal head of the fibula due to decreased fat around the peroneal nerve. Electrodiagnostic features can include axonal damage, demyelination, or both.

Conclusion: The differential for foot drop is broad, including radiculopathy, lumbosacral plexopathy, peripheral neuropathy, vitamin deficiencies, and metabolic disorders such as diabetes. However, as seen here in association with malignancy, it is important to consider Slimmer’s palsy with both significant weight loss and foot drop.

Level of Evidence: Level V

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/slimmers-palsy-in-a-patient-with-gastric-high-grade-b-cell-lymphoma-and-significant-weight-loss/