Differential awakening of the sciatic nerve: illustrative case.

backgroundDifferential awakening is a well-known, yet poorly understood phenomenon seen in patients with intracranial pathologies. Because acute postoperative neurological decline has many potentially reversible causes, distinguishing differential awakening from other etiologies is critical. To the authors' knowledge, differential awakening has not been reported following peripheral nerve procedures. OBSERVATIONS: A 40-year-old man presented with a 1.5-year history of painful bilateral cervical and right lumbosacral radiculoplexus neuropathy recently associated with bilateral facial and vestibulocochlear neuropathy. He had not responded to treatment trials. A sciatic nerve lesion in the sciatic notch was identified on imaging and an open biopsy of the posterior femoral cutaneous nerve was pursued. Immediately after emergence from anesthesia, he demonstrated a complete inability to dorsiflex or plantar flex the right foot, despite minimal intraoperative manipulation of the sciatic nerve. Over the ensuing hour, motor function progressively returned to baseline. The transient postoperative motor deficit was attributed to differential awakening of the sciatic nerve. Pathological analysis confirmed high-grade B-cell lymphoma. LESSONS: Differential awakening may be an underrecognized cause of transient neurological worsening during emergence from anesthesia following peripheral nerve surgery. Further investigation is needed to clarify the underlying mechanisms and define its incidence and risk factors. https://thejns.org/doi/10.3171/CASE251028.