Long-term follow-up of memory impairment after third ventricle colloid cyst surgery.

Introduction: Colloid cysts are rare benign but potentially lethal intracranial tumors. Treatment is surgical with open microsurgery (OS) or endoscopic surgery (ES). Postoperative memory disturbance due to fornix injury is a dreaded complication. Memory problems may severely affect life quality. Research question: To investigate the long-term memory function after colloid cyst-surgery. Materials and methods: Twenty-two patients (mean age 45 years) previously operated with OS (n = 15) or ES (n = 7) underwent objective memory testing, clinical interviews including self-estimated Quality of Life (QoL) and subjective memory questionnaires after a mean follow-up time of 7.6 years. Results: Subnormal objective memory performance was on average seen in 38 % of the patients. Cyst diameter correlated negatively to objective mean memory score (multiple R = 0.57, p = 0.005). All patients with a cyst diameter exceeding 15 mm (n = 5) had memory performance below the 10th percentile. Memory scores were similar in endoscopically and microsurgically treated patients.Objective memory performance was not correlated to subjective memory performance, sex, preoperative hydrocephalus or acute presentation.QoL ratings and depression scores were strongly correlated with the assessments of subjective memory impairment, but not with objective memory performance.There was no recurrence cyst on MRI. Discussion and conclusion: Large preoperative cysts had worse memory outcomes. Self-reported QoL and depression did not correlate with objective memory performance but with subjective memory problems. Anxiety was not associated with objective or subjective memory performance. No difference was found in objective memory performance between patients who underwent OS or ES.