Concealed long QT syndrome and intractable partial epilepsy: a case report

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Long QT syndrome (LQTS) is a cardiac channelopathy often associated with syncope due to ventricular arrhythmias.
• Epilepsy is a neurological disorder characterized by recurrent seizures.
• Concealed LQTS presents diagnostic challenges, as symptoms may be atypical.

Observation:

• A patient presented with both concealed type 2 LQTS and electroencephalogram-documented epilepsy.
• Syncope in LQTS is typically linked to arrhythmias and subsequent cerebral hypoxia.
• The patient experienced seizure-like activity, prompting investigation into a potential primary seizure disorder.

Findings:

• The case underscores the necessity of a comprehensive diagnostic approach, avoiding 'tunnel vision' in LQTS patients.
• Identifying the specific etiology of seizure-like events is crucial for appropriate therapeutic interventions.
• Abnormal KCHN2-encoded potassium channel function is hypothesized to underlie both epilepsy and arrhythmias in this patient.

Implications:

• This case broadens the understanding of LQTS presentation, including co-occurrence with primary seizure disorders.
• It highlights the potential for shared genetic or channelopathy mechanisms between epilepsy and cardiac arrhythmias.
• Clinicians should consider a dual diagnosis of LQTS and epilepsy in patients with overlapping symptoms.