Localized myokymia caused by peripheral nerve injury

Area of Science:

• Neurology
• Neurosurgery
• Musculoskeletal Medicine

Background:

• Popliteal fossa trauma, such as gunshot wounds, can lead to delayed neurological complications.
• Nerve injury in the popliteal fossa may affect the common peroneal and posterior tibial nerves, impacting lower limb function.

Observation:

• A 30-year-old male presented with gastrocnemius muscle cramps and myokymia one year post-gunshot wound.
• Myokymia manifested as vermicular, fibrillary muscle movements with toe plantarflexion and dorsiflexion.
• Symptoms were transient, resolving during sleep and spinal anesthesia.

Findings:

• Neurologic examination, nerve conduction studies, electromyography, and muscle biopsy confirmed involvement of the left common peroneal and posterior tibial nerves.
• The patient's myokymia responded to carbamazepine treatment.
• Findings suggest a link between peripheral nerve injury and persistent myokymia.

Implications:

• This case highlights the potential for delayed neuromuscular complications following popliteal fossa trauma.
• Carbamazepine may be an effective treatment for post-traumatic myokymia.
• Understanding nerve injury patterns is crucial for managing such cases.