Hypovolemia due to cerebral salt wasting may contribute to stroke in tuberculous meningitis

Abstract

Background: Both stroke and cerebral salt wasting (CSW) are common in tuberculous meningitis (TBM), but there is paucity of studies evaluating their combined effect. Aim: The present study has been undertaken to evaluate the spectrum of stroke in TBM and its relation to CSW. Design: Hospital-based prospective cohort study. Methods: Eighty-one patients with TBM diagnosed on the basis of clinical, cerebrospinal fluid and magnetic resonance imaging (MRI) criteria were prospectively included. Stroke was diagnosed on the basis of clinical, MRI findings or both. Stroke risk factors were noted. Patients with hyponatremia were categorized into CSW and other causes. Three and 6 months outcome was defined using modified Rankin Scale (mRS) as good (<2) or poor (-2). Results: Out of 81 patients with TBM, 32 (39.5%) had ischemic stroke. CSW was the commonest cause of hyponatremia and occurred in 34 (42%) patients. Stroke occurred in tubercular zone in 10, ischemic zone in 15 and both in 7 patients. The patients with ischemic zone infarction were older and had stroke risk factors such as diabetes mellitus, hypertension and hyperlipidemia. Out of 16 (47%) patients with CSW, 10 (62.5%) had stroke during the polyuric phase. The patients with CSW had more frequent deep white matter infarcts (P=0.01) which were in internal border zone in 4 (40%). Conclusion: In TBM, stroke occurred in 39.5% of the patients, 50% of whom had CSW. Volume contraction due to CSW may contribute to stroke.