Hypoglycemia and risk of seizures: a retrospective cross-sectional study.

PURPOSE: Few studies have been dedicated to assess neurological symptoms in relations to hypoglycemia. In this study we investigated the association between different levels of hypoglycemia and the occurrence of epileptic seizures in patients without a prior diagnosis of epilepsy.

METHOD: A retrospective cross-sectional study.

RESULTS

We identified 388 individuals from a laboratory database in Swedish regional hospital who had been found to have a glucose value of ≤3.5 mM between January and December 2009. Medical records were reviewed. Hypoglycemia was defined at three different categories: 0-2 mM (40 patients), 2.1-3 mM (154 patients) and 3.1-3.5 mM (194 patients). 14 patients had disturbance of consciousness including 3 with seizures. The majority of cases had coma, a generalized tonic-clonic seizure was seen only when s-glucose dropped below 2.0 mM. Two cases with focal seizure were noted, one at s-glucose 2.0 mM, and one at s-glucose 3.3 mM. The absolute risks (95% confidence interval) for having major neurological symptoms at glucose levels of ≤2.0 mM were 0.25 (0.13-0.41), 0.02 (0-0.06) at 2.1-3.0 mM and 0.01 (0-0.03) at 3.1-3.5 mM.

CONCLUSION

Coma is the most common neurological symptom related to hypoglycemia. Epileptic seizures are rare and not as common as previously assumed.