Value of tongue biting in the diagnosis of seizures.

BACKGROUND: Seizures are rarely witnessed by physicians, and the diagnosis is usually made on the basis of the history. Tongue biting is classically considered to favor a diagnosis of epileptic seizure. The usefulness of tongue biting in the differential diagnosis of seizures was evaluated.

METHODS: A prospective study of the presence of oral lacerations in 106 consecutive patients admitted to our Epilepsy Monitoring Unit and a retrospective study of a population of 45 patients with syncope were performed. The relationship between tongue biting and diagnosis (epileptic vs nonepileptic events) was analyzed.

RESULTS: Of the 106 monitored patients, 63 had episodes characterized by bilateral motor activity, complete loss of consciousness, or both; 34 patients had epileptic seizures, while 29 patients had exclusively nonepileptic episodes. Eight patients suffered an oral laceration; all involved the side of the tongue, and all had documented epileptic seizures. Of the 45 patients with syncope, in only one was the tongue lacerated, and this was at the tip. Tongue biting had a sensitivity of 24% and a specificity of 99% for the diagnosis of generalized tonic-clonic seizures. Lateral tongue biting was 100% specific to grand mal seizures.

CONCLUSION: Tongue biting, particularly if it is lateral, is highly specific to generalized tonic-clonic seizures.