ODP299 Cabergoline Administration Markedly Improves Cognitive Impairment Associated with Macroprolactinoma

INTRODUCTION: Prolactinomas classically present with galactorrhea, infertility, or hypogonadal symptoms. However cognitive impairment is rare presentation. We describe a man with a macroprolactinoma presenting with significant cognitive dysfunction which improved remarkably with cabergoline treatment. CASE HISTORY: A 21-year-old man with no significant past medical history presented to the hospital for evaluation of seizure-like activity. His father noted him limping earlier in the day and witnessed him fall and hit his head, while his brother reported involuntary convulsions and decreased awareness earlier that week. The patient himself had been complaining of blurry vision for 3 months for which he was prescribed glasses. Initial head CT demonstrated a 3.4×4.3×3.4cm cystic mass in the sella, 3.9×3.2×2.6 cm mass in the right basal ganglia and 2.7×2.3×3cm mass in the right temporal lobe. His prolactin was elevated at 16326 ng/mL. He was empirically started on dexamethasone due to concern for cerebral edema and was admitted. Surgery was recommended given the severity of his presentation, but the patient declined and he was discharged on cabergoline 1.5mg/week, dexamethasone taper, hydrocortisone 15mg/day, and levetiracetam 1000mg twice daily. On initial outpatient endocrinology evaluation 3 weeks later, he required the use of a wheel chair. Examination was notably for markedly flat affect, slurred speech, decreased attention span requiring frequent re-direction during the interview but he was otherwise oriented to person, time, and place. Neurological examination was noted for 4/5 muscle weakness throughout, facial asymmetry, decreased facial sensation, and an antalgic gait. He was recommended for expedited neurosurgical evaluation but he again declined. Laboratory drawn at this time showed a prolactin of 1946 ng/mL and total testosterone of 45 ng/dL, but he had normal thyroid and growth hormone axis (adrenal axis was not assessed as he was on dexamethasone taper). Carbergoline was titrated with further improvement in his prolactin levels. Four months after initial presentation, he reported enrolling in college with resolution of any cognitive and neurological deficits. Fourteen months after presentation, serum prolactin was 34 ng/mL on 4mg cabergoline per week and he is active in college and regularly plays basketball. DISCUSSION: Prolactinomas are incidentally detected or found as a result of workup for galactorrhea, infertility, or low libido. Typically, goals for treatment are to relieve compressive effects along the optic chiasm or to restore gonadal function. Acute cognitive decline should also be considered when there is a macroprolactinoma, and serial monitoring for improvement may be considered a clinical marker along with MRI imaging and prolactin levels. In this case, the patient had marked cognitive dysfunction on initial presentation but after 3 months of treatment had almost complete recovery as evidenced by his re-enrolling in college classes successfully. Presentation: No date and time listed