Cations of cisternal cerebrospinal fluid in humans and the effect of different doses of nimodipine on CSF calcium after stroke

Cisternal samples of cerebrospinal fluid (CSF) were analyzed for protein, a lbumin, sodium (Na), potassium (K), and calcium (Ca) content in 21 control subjects and 64 patients who had experienced acute stroke. A second cistern al CSF sample was taken in 37 of the stroke patients after 2-3 weeks treatm ent with the calcium antagonist nimodipine. Increased permeability of the b lood-brain barrier was reflected by the significantly higher CSF/serum rati o of albumin in stroke patients than in control subjects (0.0046 vs. 0.0028 , p = 0.0012). Serum and CSF concentrations of Na, K, and Ca did not differ between control subjects and stroke patients. In control subjects and in s troke patients, concentration of calcium in cisternal CSF ([Ca]) was smalle r than values reported by others in lumbar samples. In stroke patients, the pH of CSF was lower than that of simultaneously taken blood (7.38 vs. 7.44 , p < 0.001). No differences between stroke patients and control subjects w ere found for the cisternal CSF/serum ratios of Na (1.0 and 0.99), K (0.61 and 0.63), and Ca (0.25 and 0.24). When patients and controls were pooled t ogether, CSF total [Ca] correlated weakly with serum total [Ca] (Spearman r = 0.28, p = 0.014) and with serum ionized [Ca] (Spearman r = 0.27, p = 0.0 16). After 2-3 weeks of nimodipine treatment, CSF [Ca] was significantly lo wer in the subgroup treated with 60 mg nimodipine four times daily (240 mg/ d) than with 30 mg four times daily. A nimodipine dosage of 30 mg four time s daily (120 mg/d) did not affect CSF [Ca]. A 240 mg daily dosage, but not a 120 mg daily dosage, of nimodipine may affect the Ca transport system in humans at the choroid plexus.