Prolonged QT syndrome presenting as epilepsy
Gatto EM, Zurrú MC, and González MA (1996) Prolonged QT syndrome presenting as epilepsy. Neurology p. 1188.
To the Editor: Pacia et al. [1] reported two cases and reviewed eight patients with long QT syndrome (LQTS) initially diagnosed as primary epilepsy. Recently, we described a 17-year-old woman with an idiopathic LQTS presenting as epilepsy. [2] Three years before consultation, she began episodes of loss of consciousness and generalized tonic-clonic seizures. Epilepsy was diagnosed, and she was put on phenobarbitone. There was no evidence of nerve deafness or family history of epilepsy or cardiac arrhythmia. She continued to have occasional blackouts. A resting ECG showed a prolonged QT interval of 0.68 double prime, QTc 0.71 double prime. A further episode required direct-current cardioversion. The treatment with beta blockers controlled the ventricular arrhythmias and seizures. The mortality rate in LQTS is estimated to 77% and drop to 7% in patients under treatment: [3] in this sense we agree with the authors to provide in all EEG record one ECG channel, because this easy procedure can detect a life-threatening disorder. However, a single QT measurement may not be sufficient to make the diagnosis and an exercise test must be done to show LQTS.
Context
- Comment on Pacia et al. emphasizing the advisability of including EKG as one channel on EEG for detection of arrhythmia presenting as seizure.