Hypothalamic-pituitary insufficiency following infectious diseases of the central nervous system

Objective: Hypothalamic-pituitary insufficiency may have diverse causes. The aim of this study was to determine the incidence of hypothalamic-pituitary insufficiency in patients with previous infectious diseases of the central nervous system (CNS) of different etiologies and mild-to-moderate clinical course. Design: Patient series. Basal and stimulated (insulin tolerance test) pituitary function testing was performed in 19 patients with previous neuroborreliosis. encephalitis, or meningitis following an interval of between 10 and 5 6 months (mean 2 6.1 +/- 13.1 months) after the acute event. Results: Four patients (21%; two males, two females) showed an isolated corticotropic insufficiency (peak cortisol <181.25 mu g/l during the insulin tolerance test). Two patients (11%, males) showed borderline gonadotropic insufficiency (basal testosterone between 2.4 and 3.0 mu g/l). No patient had somatotropic or thyrotropic insufficiency or evidence for diabetes insipidus: all had prolactin concentrations within the reference range. Conclusions: Hypothalamic-pituitary dysfunction and especially isolated corticotropic insufficiency may develop in a relevant proportion of patients after infectious diseases of the CNS.