Diagnosis of functional neurological disorders mimicking brachial plexus injury

Brachial plexus injury (BPI) is the most devastating peripheral nerve injury that occurs following high-energy trauma. Rarely, patients with functional neurological disorders (FND) are referred to orthopaedic surgeons with symptoms mimicking brachial plexus injury. This study investigated the clinical features and prognosis of patients with psychogenic upper limb paralysis who were referred to our department because of suspected brachial plexus injury.

The study included 13 patients who were referred to a university hospital between 2013 and 2023 with suspected BPI from the referring hospital but were diagnosed with FND based on physical, imaging, and neurophysiological examinations. There were eight men and five women, mean age was 31.5 years (range, 13-54 years). The referral hospital, mechanism of injury, timing of symptom onset (paralysis development), initial physical examination findings, and prognosis (course of recovery) were retrospectively reviewed.

None of the patients exhibited muscle atrophy, all had normal upper limb tendon reflexes, and a discrepancy was noted between the levels of motor weakness and sensory impairment. All patients were referred by orthopaedic surgeons with a presumed diagnosis of brachial plexus injury. The primary treatment involved helping patients realize they could move their limb through direct electrical stimulation to the brachial plexus, without explicitly stating that the paralysis was psychogenic. More than half of the patients showed improvement during follow-up.

A meticulous physical examination is crucial for distinguishing FND from BPI. All patients were referred by orthopaedic surgeons, highlighting that BPI is a difficult diagnosis, even among specialists.