Working Diagnosis:
Slimmer's paralysis with bilateral peroneal neuropathy.

Treatment:
Initial treatment in primary sports medicine office was bilateral peroneal nerve hydro-dissection performed with ultrasound guidance. Patient got short-lasting relief from this procedure and her symptoms recurred in the week or two following the procedure. Case Photo #3 Case Photo #4

She was interested in definitive relief and was referred to an orthopedic sports surgeon. She then underwent open peroneal nerve decompressions, one side at a time.

Outcome:
The patient elected to have open peroneal nerve decompression surgery. She had left-side surgery first which resulted in resolution of foot drop on the left. She subsequently had the same surgery on the right. She recovered well from both procedures and no longer has difficulty ambulating. She regained her normal gait and no longer experiences lower extremity weakness or difficulty walking.

The patient recovered well from her two decompression surgeries, performed 1 month apart. She began to walk further distances without any discomfort, no longer needing closer parking at work. She eased back into her physical activities including incline treadmill walking, walking outdoors and strength training in the gym. She rebuilt her strength and is no longer limited by lower extremity weakness.

Author's Comments:
Slimmer's paralysis or peroneal nerve neuropathy is caused by the loss of fatty tissue around the fibular nerve at the fibular head. It has been documented in the literature with a resurgence since the widespread use of GLP-1 medication for weight loss. Weight loss with these medications is faster which exacerbates the abrupt loss of fatty tissue that normally cushions the fibular nerve. Patients who take GLP-1 medications often have diabetes, which itself is a risk factor for peroneal nerve compression due to elevated blood sugars causing peripheral nerve swelling. Recent studies show an increased number of cases of peroneal nerve neuropathy reported in correlation with GLP-1 prescriptions.
This case highlights a phenomenon that is not new but becoming more prevalent due to the widespread use of GLP-1 agonists. Rapid weight loss in particular may predispose individuals to peroneal nerve compression. It is important for sports medicine physicians to ask patients about weight loss when evaluating symptoms such as lower extremity weakness and foot drop and consider the amount of time during which they lost the weight.

Editor's Comments:
Peroneal neuropathy is the most common of the lower extremity nerve entrapment syndromes. The symptoms are numbness or paresthesia of the shin and top of the foot. In more severe cases it may cause weakness leading to foot drop and the inability to actively dorsiflex the ankle or extend the toes. In these cases, patients may experience a steppage type gait pattern. It is most commonly compressed at the fibular head affecting the common peroneal nerve. If compression occurs more distally, it may affect the superficial or deep peroneal nerves in isolation.
Common Peroneal Neuropathy, as this case highlights, occurs from external compression (crossing legs, prolonged kneeling, or tight garments or casting), physical trauma, or rapid weight loss. Medical conditions such as diabetes, inflammatory arthritis, or systemic neuropathy may predispose patients to peroneal neuropathy.
In most cases, relieving pressure on the nerve through habit changes or not wearing tight garments will resolve the neuropathy. If the foot drop is severe, an AFO can be used. Physical therapy may be needed to improve strength and function. In recalcitrant cases, surgical decompression is an option.

References:
Cucu L-E, Popescu G, Maștaleru A, Ignat EB, Grosu C, Bîrsanu L, Leon MM. Common Peroneal Nerve Paralysis Following Rapid Weight Loss�"A Case Report and Literature Review. Nutrients. 2025; 17(11):1782.​
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Fares MY, Dimassi Z, Fares J, Musharrafieh U. Peroneal neuropathy and bariatric surgery: untying the knot. International Journal of Neuroscience. 2020;130(4):417-423.
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O'Gorman, C. Peripheral nerve complications of weight loss associated with novel antihyperglycemic agents: a cohort study. J Neurol 273, 33 (2026).​
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Tucker JM, Ritchie J. The Tirzepatide Drop: Beware of Slimmer's Paralysis. Journal of Investigative Medicine High Impact Case Reports. 2024;12.​

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