IntroductionTuberculous meningitis (TBM) brings significant morbidity and mortality worldwide. Hyponatremia has long been documented as a potentially grave metabolic result of TBM. The syndrome of inappropriate antidiuretic hormone (SIADH) secretion has been supposed to be accountable for the majority of cases of hyponatremia in TBM. Cerebral salt wasting syndrome (CSWS) is being progressively reported as a basis of hyponatremia in some of these cases. Differentiating CSWS from SIADH can be challenging but is vital because treatment of these two conditions is profoundly different.ObjectiveThe rationale of our study is to determine the frequency of hyponatremia and etiology in patients presenting with TBM in a tertiary care hospital in order to establish the local perspective as there is paucity of local data.MethodsA total of 160 hospitalized patients at a tertiary care hospital in Pakistan who fulfilled the inclusion criteria were enrolled in this study after informed consent. The study was conducted for six months at the department of neurology, Jinnah Postgraduate Medical Centre (JPMC), Karachi, Pakistan. Brief history was taken and demographic information was entered in the performa by researchers. The data was collected and analyzed on Statistical Package for Social Sciences (SPSS) version 18.0 (IBM Corp., Armonk NY, USA). Demographic data were presented as simple descriptive statistics giving mean and standard deviation for age, height, weight, GCS (Glasgow Coma Scale), serum sodium and duration of symptoms. Frequencies and percentages were calculated for categorical variables like gender, hypertension, smoking status, T2DM (Type 2 Diabetes Mellitus), BMRC (British Medical Research Council Contemporary Clinical Criteria for TBM) stage, hyponatremia, SIADH and CSWS. Effect modifiers were controlled through stratification of age, gender, hypertension, smoking status, T2DM, BMRC stage and duration of symptoms to see the effect of these on the outcome variable (hyponatremia). Quantitative data were presented as simple descriptive statistics giving mean and standard deviation and qualitative variables were presented as frequency and percentages. Post stratification chi-square test was applied with a p-value of ≤0.05 taken as significant.ResultsIn our study, out of 160 patients with TBM, 40% (64) had hyponatremia. Moreover, 14.4% and 25.6% had SIADH and CSWS, respectively with 60% (96) of patients were male and 40% (64) were female. Mean age of patients in our study was 46.78±2.81 years. Whereas, mean duration of symptoms, serum sodium, GCS, height and weight in our study was 1.2±0.78 weeks, 128.65±7.52 mmol/L and 11.21±3.14%, 158±7.28 cm and 78.7±9.87 kg, respectively.ConclusionThis study concluded that the frequency of hyponatremia among patients of TBM was significant, consistent with previous studies. Privation of proper assessment and management can lead to grave and permanent neurological consequences, as well as death. Healthcare providers should be aware of the implication of sodium deregulation among patients of TBM and differentiate between the numerous therapeutic preferences in order to advocate safe and effective treatment.