Case Presentation: A 50-year-old lady developed recurrent Cushing's disease after being in remission following transsphenoidal surgery (TSS) for a left pituitary microadenoma 16 years ago. The repeat MRI showed a right pituitary microadenoma (1.7 mm × 1.3 mm) for which she underwent a second TSS. However, she continued to have persistent hypercortisolism despite repeated MRIs showing absence of tumour recurrence. She refused bilateral adrenalectomy and external radiotherapy. Ketoconazole was commenced at 200 mg twice daily for disease control but this was hindered by intolerable side effects including pruritus and skin exfoliation. In the meantime, she suffered a right hypertensive basal ganglia hemorrhage. Treatment was subsequently switched to cabergoline and the dose titrated to 0.5 mg daily. Fluconazole 400 mg daily was later added to control the persistent disease. Her clinical and biochemical parameters improved markedly three months after the addition of fluconazole. No adverse event was reported. Her disease has remained stable for the last 15 months up until the time of the recent clinic review.

METHODS: This was a single-center cross-sectional study. We recruited 159 participants diagnosed with epilepsy on antiseizure medications (ASMs). We included those aged 18 years and above, excluding patients with long-term medical conditions that would affect vitamin D metabolism. Sociodemographic data and details of epilepsy were collated. Venous sampling was performed to analyze the levels of albumin-corrected calcium, phosphate, alkaline phosphatase, and 25-hydroxyvitamin D3 [25(OH)D]. Serum 25(OH)D level is defined as deficient (<20 ng/ml), insufficient (20-29 ng/ml), and sufficient (≥30 ng/ml).