[Hypocalcemia and convulsive syndrome in alcoholics--an association frequently not diagnosed]

Hypocalcemia can be a contributory factor for epilepsy and previous studies showed that ethanol decreases plasma calcium.

To establish the prevalence of hypocalcemia in the general convulsive population and to ascertain if there was a specific group of risk for hypocalcemia.

A prospective study of plasma ionized calcium measurement in 78 consecutive patients admitted owing to seizures at the Emergency Department of Escola Paulista de Medicina was performed. 22% of these patients were alcoholics. The plasma ionized calcium in 44 ambulatory non-convulsive alcoholics was also measured.

A high prevalence of hypocalcemia was found in the alcoholic convulsive population (32%), in contrast with the non-alcoholic convulsive group and the alcoholic non-convulsive group (no calcium disturbance in both groups). The alcoholic convulsive group had values of ionized calcium statistically lower than the non-alcoholic convulsive group using the Mann-Whitney test (p < 0.05) [median value = 1.20 mmol/L; range = 1.04-1.32 mmol/L/median value = 1.24 mmol/L; range = 1.16-1.29 mmol/L respectively]. The alcoholic non-convulsive group had values of ionized calcium between 1.17 and 1.32 mmol/L with median value of 1.26 mmol/L; these values were not different from those obtained with the non-alcoholic convulsive patients, however they were higher than the calcium levels in the alcoholic convulsive group (p < 0.05). PTH levels, liver function tests, phosphatemia and amylasemia were normal in all patients.

This study emphasizes the importance of serum calcium measurement in alcoholic patients presenting seizures and suggests that hypocalcemia correction might be important in these patients.