High sciatic lesion mimicking peroneal neuropathy at the fibular head.
We report 4 patients with severe, axon-loss, high sciatic mononeuropathies affecting exclusively the peroneal fibers: a boy with a slowly-growing nerve tumor, a woman with an injection injury, and 2 patients who had undergone proximal femur surgery. Clinically, the findings mimicked those seen with common peroneal neuropathy at the fibular head. The peroneal conduction studies were very low in amplitude/unelicitable. Conversely, the tibial studies and H-responses were normal in all; the sural responses were normal in one while low in amplitude/unelicitable in the remaining three. The biceps femoris, short-head, and all peroneal-innervated muscles showed fibrillations and profound motor unit loss. Conversely, the remaining hamstrings and all tibial-innervated muscles were normal. We conclude that a sciatic lesion can imitate a more distal peroneal lesion. Needle EMG of the biceps femoris, short head, is essential for correct diagnosis.
Katirji
B
B
Department of Neurology, Case Western Reserve University, University Hospitals of Cleveland, OH 44106.
Wilbourn
A J
AJ
D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D000368:Aged; D002648:Child; D004576:Electromyography; D005260:Female; D005360:Fibula / Q000473:pathology*; D006181:H-Reflex / Q000502:physiology; D006801:Humans; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology; D009442:Neurilemmoma / Q000503:physiopathology; D009475:Neurons, Afferent / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology*; D010524:Peripheral Nervous System Neoplasms / Q000503:physiopathology; D010543:Peroneal Nerve / Q000503:physiopathology*; D012584:Sciatic Nerve / Q000503:physiopathology*; D013497:Sural Nerve / Q000503:physiopathology