Abnormal electroencephalograms in patients with long QT syndrome

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Long QT syndrome (LQTS) is an inherited cardiac channelopathy linked to sudden cardiac death, often caused by potassium channel mutations.
• Potassium channels are crucial in both cardiac and brain function, with mutations potentially linking LQTS and epilepsy.
• Emerging evidence suggests co-expression of epilepsy and LQTS in individuals with related potassium channel mutations.

Purpose of the Study:

• To investigate cerebral electrical activity using electroencephalography (EEG) in individuals diagnosed with LQTS.
• To explore the relationship between LQTS, specifically that caused by potassium channel mutations, and brain activity patterns.

Main Methods:

• Seventeen patients with confirmed LQTS (11 LQT1, 6 LQT2) underwent 21-channel EEG.
• Clinical data including LQTS symptoms, comorbidities, medications, and QTc intervals were collected.
• EEG findings were compared to a control group of 16 healthy individuals and analyzed by two neurophysiologists.

Main Results:

• Abnormal EEG findings were observed in 71% (12/17) of LQTS patients, compared to 13% (2/16) of controls (P < .01).
• Common abnormalities in LQTS patients included theta activity and sharp waves; two patients also showed delta activity.
• No patients exhibited definitive epileptic activity such as spikes or spike waves on EEG.

Conclusions:

• Cerebral electrical activity is significantly more abnormal in LQTS patients with potassium channel mutations than in healthy controls.
• These findings suggest a potential association between cardiac channelopathy (LQTS) and cerebral channelopathy.
• Further research is warranted to elucidate the precise mechanisms linking these conditions.