Brachioradial Pruritus: Clinical, Electromyographic, and Cervical MRI Features in Nine Patients

Background Brachioradial pruritus (BRP) is a neuropathic dysesthesia manifesting as pruritus over the dorsolateral forearm. While the etiology is unknown, intensive sun exposure and cervical spine disease have been proposed. This study describes the clinical, electrodiagnostic (EDX), and cervical MRI findings in nine patients diagnosed with BRP. Materials and methods All patients underwent EDX and cervical MRIs. Numerous metrics were documented including presenting symptoms, neurological examination, EDX findings, and cervical MRI features. Results All nine patients experienced pruritus of the arms/forearms, typical of BRP, which was unilateral in eight (89%) cases. Decreased pinprick sensation was noted in the arms/forearms (five [56%] patients) or of the thumbs, index, and/or middle fingers (four [44%] patients). Four (44%) patients had either decreased or absent biceps and brachioradialis deep tendon reflexes (DTRs), while one (11%) patient had decreased triceps and brachioradialis DTRs. The EDX revealed abnormalities in eight (89%) patients. Increased polyphasic units, decreased motor units, and/or denervation changes were recorded by needle electromyography (EMG) in eight (89%) patients: the biceps in seven (88%) and both the brachioradialis and triceps in four (50%) patients. The EMG abnormalities indicated chronic radiculopathy involving C6 in six patients and C5 and C6 in one patient. All nine patients had cervical spine disease, encompassing disc protrusions, spondylosis, spinal stenosis, and/or foraminal stenosis. Conclusions BRP in this series of patients was accompanied by chronic cervical radiculopathy involving predominantly C6 and C5. EDX and cervical spine MR imaging should be considered essential investigations in the evaluation of patients with BRP.