Narcolepsy secondary to fourth ventricular subependymoma

Abstract

Background: Secondary (symptomatic) narcolepsy is rare. We report a subependymoma of the fourth ventricle associated with narcolepsy. The patient was a 50-year-old woman with a long history of narcolepsy who died of colonic carcinoma with no cerebral metastasis. She was positive for HLA-DR2. At autopsy there was a tumour dorsal to the fourth ventricle which involved the midbrain tectum and rostral pons. Histologic examination of the tumour confirmed it to be a subependymoma. Methods: Review of the previous cases of secondary narcolepsy was made with particular reference to the anatomical location of the lesions. Results: Most of the lesions were found around the third ventricle and rostral brainstem. Conclusions: Knowing the anatomical localization of the pathological changes in secondary narcolepsy could be important in improving our understanding of its pathogenesis.