Adult onset tethered cord syndrome presenting with unilateral calf atrophy

Adult-onset lower extremity weakness caused by venous malformation detected by magnetic resonance imaging

INTRODUCTION

Symptomatic venous malformation (VM) of muscle in adults is rare and usually presents in childhood or adolescence as the individual is growing. We describe an atypical presentation of a malformation affecting the gastrocnemius muscle asymmetrically with onset in adulthood, which created a diagnostic challenge. Electromyography (EMG) and muscle biopsy did not fit clinically and MRI of the gastrocnemius led to the diagnosis.

METHODS

The setting for the patient studied was a neuromuscular outpatient clinic.

RESULTS

EMG showed decreased insertional activity and motor unit potential recruitment in the right gastrocnemius muscle. Muscle biopsy showed mild neurogenic changes. MRI demonstrated VM in the contralateral gastrocnemius muscle.

CONCLUSIONS

This case represents a rare cause of atrophic weakness in adults, but muscle MRI should be considered when other tests are equivocal.