Recurrent wrist drop in a patient with NBIA

초록

INTRODUCTION Wrist drop refers to a condition where there is weakness or paralysis of the muscles responsible for extending or lifting the wrist. Causes of wrist drop due to radial nerve palsy include trauma, entrapment, prolonged pressure, or certain medical conditions such as vasculitis, multifocal motor neuropathy, tumor, anatomical variations, etc. We experienced a case of recurrent radial nerve palsy caused by abnormal posture in a patient with neurodegeneration with brain iron accumulation (NBIA) disorder. CASE REPORT She is currently 32 years old and was diagnosed with NBIA caused by mutations in the PLA2G6 gene, 17 years ago. NBIA is a group of rare neurodegenerative disorders characterized by progressive extrapyramidal dysfunction, iron accumulation in the brain, and the presence of axonal spheroids in the central nervous system. She had been regularly visiting the neurology clinic for ongoing dystonia, gait disturbance, and cognitive impairment. She presents to the outpatient department with a right wrist drop that occurred a few days ago. Physical examination revealed poor finger and thumb extension grades, along with trace grade for wrist extension and no sensory changes. She had previously presented with similar symptoms and received a diagnosis of radial nerve palsy 8 months earlier. The caregiver reported a habit of sleeping with her right arm bent under her head, which had persisted recently. Notably, her condition had previously shown improvement through corrective postural education and injection therapy. One week later, we performed ultrasonography to evaluate radial nerve injury around both elbows. Swelling was observed in the spiral groove area between 8cm and 10cm above the right elbow, compared to the left side. A sono-guided injection was administered, using triamcinolone (20mg) and lidocaine (2.5cc), targeting the right radial nerve (Figure 1). Two weeks after symptom onset, neurophysiologic testing revealed normal motor, sensory, and