Abstract
BACKGROUND: Cerebral vasospasm is a rare yet serious complication of transsphenoidal surgery (TSS). While its etiology is incompletely understood, early detection is critical for proper management. OBSERVATIONS: The authors report the case of a 35-year-old female with acromegaly who underwent TSS for resection of somatotroph macroadenoma. The adenoma was completely removed with its pseudocapsule, and no CSF leakage was encountered. Postoperative imaging was notable for blood products in the interpeduncular cistern. A week after surgery, she presented to the clinic with dysarthria, right-sided ataxia, and right eye exotropia. CT angiography identified vasospasm at the basilar tip, with subsequent MRI demonstrating an infarction of the midbrain. The patient was admitted, underwent aggressive fluid resuscitation, and then discharged after vitals had stabilized and ambulation and speech had improved. Incomplete right eye convergence resolved by the 3-month follow-up. LESSONS: The authors present a rare case of cerebral vasospasm following transsphenoidal resection of a pituitary macroadenoma and discuss the effect on midbrain tracts involved in vergence. https://thejns.org/doi/10.3171/CASE25453.