atrial-natriuretic-factor and Tuberculosis--Meningeal

To report atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels in patients with tuberculous meningitis (TBM) and acute encephalitis syndrome (AES), and evaluate their relationship with hyponatraemia.. Consecutive patients with TBM and AES were included in the study. Hyponatraemia was categorised as cerebral salt wasting (CSW), syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and a miscellaneous group based on clinical and laboratory criteria. Serum ANP and BNP levels were measured upon hospital admission, at the time of diagnosis of hyponatraemia and upon correction of hyponatraemia. Outcome at 3 months was assessed using the modified Rankin scale (mRS) as good (mRS 2) and poor (mRS >2).. There were 67 patients with TBM and 77 with AES. Hyponatraemia was more common in TBM than in AES (65.7% vs. 27%, P < 0.01). Forty-one (63.1%) patients had CSW, 6 (9.2%) SIADH and 18 (27.7%) had miscellaneous causes of hyponatraemia. During hyponatraemia, ANP (180 ± 45 vs. 106 ± 32 pg/ml, P < 0.01) and BNP (263 ± 118 vs. 163 ± 91 pg/ml, P  0.01) levels were significantly increased compared with baseline, and remained high even after Na+ correction.. ANP and BNP levels were increased during hyponatraemia and remained high even after correction of hyponatraemia in TBM and AES, especially in patients with CSW. However, ANP and BNP levels could not be used to differentiate CSW from SIADH.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Atrial Natriuretic Factor; Child; Encephalitis; Female; Humans; Hyponatremia; Inappropriate ADH Syndrome; Male; Middle Aged; Natriuretic Peptide, Brain; Prospective Studies; Tuberculosis, Meningeal; Young Adult

Hyponatremia has been reported in up to one third of patients with intracranial disease and has frequently been associated with tuberculous meningitis, often complicated by hydrocephalus. The lowered plasma sodium levels were previously attributed to the syndrome of inappropriate secretion of antidiuretic hormone. A controlled prospective study of 24 patients with tuberculous meningitis and hydrocephalus was carried out. Analyses of serum electrolytes and cerebrospinal fluid were performed. Plasma and cerebrospinal fluid levels of atrial natriuretic peptide (ANP) and antidiuretic hormone (ADH) were measured by radioimmunoassay. Fifteen patients were found to be hyponatremic (plasma sodium < 130 mmol/L) and ANP levels of 12 to 1,488 pg/ml were present (median, 26 pg/ml). The remaining 9 patients had normal plasma sodium values between 130 and 145 mmol/L, and in these, plasma ANP values varied between 12 and 21.7 pg/ml (median, 12 pg/ml). The difference between these two groups was not statistically significant. (Control values from patients undergoing myelography were established to range between 12 and 40 pg/ml; median, 14.4 pg/ml.) ANP levels were undetectable in the cerebrospinal fluid in all. Plasma ADH levels in the hyponatremic group were between 7 and 159 pg/ml (median, 40 pg/ml). In the normonatremic group, plasma ADH levels of 25 to 250 pg/ml (median, 29 pg/ml) were obtained. (The controls ranged between 3.6 and 35 pg/ml; median, 10.4 pg/ml). In the hyponatremic group, there was a moderate negative correlation (r = -0.683) between plasma ANP and plasma sodium (P = 0.02). No correlation between plasma ADH and plasma sodium was found (r = -0.168; P = 0.62).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Atrial Natriuretic Factor; Blood-Brain Barrier; Humans; Hyponatremia; Inappropriate ADH Syndrome; Natriuresis; Neurologic Examination; Tuberculosis, Meningeal; Water-Electrolyte Balance