Narcolepsy secondary to fourth ventricular subependymoma.

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.