Acute parkinsonism as an unexpected consequence of pituitary adenoma resection: A case report

INTRODUCTION: Transsphenoidal resection of pituitary tumors is a surgery performed through the nose and sphenoid sinus to remove pituitary tumors. Disorders of sodium balance are common after transsphenoidal surgery involving the pituitary gland. Here, we report the clinical features of an original case of acute onset parkinsonism later confirmed to be secondary to transsphenoidal resection of pituitary adenoma. PATIENT CONCERNS: A 36-year-old female had received transsphenoidal pituitary resection for pituitary adenoma. Eight days after the surgery, she suffered from acute onset general weakness and nausea/vomiting. She was diagnosed with hyponatremia for which she was treated. Acute onset ataxia, bilateral hand tremor, and dysarthria were then noted on the 4th day of hyponatremia treatment. DIAGNOSIS: Based on history, clinical manifestation, and MRI brain images, a diagnosis of acute parkinsonism caused by isolated extrapontine myelinolysis (EPM) was made. INTERVENTIONS: Patient was treated with levodopa/carbidopa. OUTCOMES: Patient's symptoms and signs improved gradually and 2 month follow-up MRI brain showed significant resolution of the bilateral lentiform nuclei hyperintensities on the T2-weighted images. Her neurological deficits had subsided completely. LESSONS: This case highlights an unexpected association between transsphenoidal resection of pituitary tumors and acute parkinsonism which is a treatable manifestation of EPM. Correction of hyponatremia following transsphenoidal pituitary resections should be preceded cautiously because even gradual correction of hyponatremia can produce myelinolysis.