Objective:

This case series describes fibular neuropathy at the knee following rapid weight loss to GLP-1 receptor agonists.

Background:

Rapid weight loss may cause a compression of the fibular nerve at the knee from loss of subcutaneous fat around the fibular head, leading to Slimmer’s paralysis. This is characterized by weakness of dorsiflexion (foot drop), causing significant morbidity due to gait disturbance, falls, and chronic pain.

Design/Methods:

n/a

Results:

We identified 6 patients presenting with foot drop who had rapid weight loss with GLP-1 receptor agonist use. Three were on tirzepatide and three were on semaglutide. EMG/NCS showed evidence of fibular nerve compression at the knee.  An average weight loss of 54.17 pounds over 11.33 months (standard deviation 28.09 and 7.82 respectively). Three patients had elected to undergo fibular nerve decompression surgery.

Conclusions:

With the increased use of GLP-1 receptor agonists, rapid weight loss has become increasingly common. There is no evidence on how the rate of weight loss increases the risk of fibular neuropathy and what can be done to monitor and reduce the risk for individuals. This case study seeks to correlate the rate of weight loss from GLP-1 receptor agonist use with increased risk of compressive fibular mononeuropathy.