(Kiosk 2) A Case of T3-T4 Syrinx with New Onset Foot Drop

Case Diagnosis: Foot drop due to common peroneal nerve neuropathy (Strawberry Pickers' Palsy).

Case Description or Program Description: A 48-year-old female presented with a 1-week history of painless foot drop of the right side. She has had a known syrinx of her T3-T4 spinal canal. For 2 months, the patient has been bicycling 100 miles per week and squatting 100 times per session. On physical exam, the patient had right lower extremity (RLE) radicular pain in the L5 distribution with inability to walk on her toes. Dorsiflexion motor strength of the RLE anterior tibialis was 2/5 and extensor hallucis longus motor function was 1/5. RLE sensory loss was noted at the L5 distribution. Decreased achilles/patellar reflexes were noted, 1/4 bilaterally. During ambulation, steppage-gait was seen from right-sided foot drop.

Setting: Outpatient clinic.

Assessment/Results: Right fibular nerve evaluation showed decreased conduction velocity. Needle evaluation of the right tibialis anterior muscle revealed diminished recruitment. The right EHL showed slightly increased spontaneous activity and diminished recruitment. Therefore, electrodiagnostic evidence was found of the right deep peroneal nerve causing neuropraxia below the knee affecting motor components.

Discussion (relevance): The case report is a rare manifestation of foot drop due to strawberry pickers’ palsy. On EMG, right fibular nerve findings confirmed decreased conduction velocity. Evaluation of the tibialis anterior muscle revealed diminished recruitment. Thus, confirming a neuropraxia below the knee of the deep peroneal nerve. With this diagnostic information, the authors believed there is no relation of her syrinx to the sudden onset of foot drop. Additionally, the patient was advised to discontinue her squatting and cycling routine until symptoms improved.

Conclusions: Although syringomyelia is a rare central cause of foot drop with very few case reports suggesting this, it must still be ruled out with further investigation. This case highlights the importance of the H&P to further elucidate central causes of rapid onset foot drop.