Hyperammonemia is associated with generalized convulsion.

PURPOSE The possibility that hyperammonemia may be associated with generalized convulsion (GC) was retrospectively investigated. METHODS Subjects comprised 17 patients with GC who were transported to our department and underwent analysis of serum biochemistry, including ammonia, since October 2004. RESULTS Causes of convulsion included intracranial lesions (n=8), endocrine diseases (n=2), epilepsy (n=2) and others (n=5). Ammonia levels in all cases exceeded the upper limit of normal range. Ammonia levels in 8 subjects were re-checked on hospital day 2, and all were lower than levels on hospital day 1 without any treatment for hyperammonemia. CONCLUSION GC itself appears to be associated with hyperammonemia. Although hyperammonemia is also known to induce convulsion, biochemical analysis immediately after GC is not useful for diagnosing hyperammonemia-induced convulsion.