Co-morbid seizures in frontotemporal dementia: What do they tell us?

Comorbid seizures occur in 2-11 % of frontotemporal dementia(FTD). Despite the high risk for seizures, the risk factors, clinical characteristics, and seizure outcomes in FTD patients with comorbid seizures remain understudied.

All patients who presented to our hospital from 5/1/2011-4/30/2024 with a clinical diagnosis of FTD were included and subclassified into behavioral-variant FTD(bvFTD), sematic-variant-primary-progressive-aphasia(svPPA), or non-fluent-primary-progressive-aphasia(nfPPA). Demographics, comorbidities, dementia characteristics, and seizure characteristics were obtained from electronic medical records. Patients were classified into those with(FTD+SZ) or without(FTD-SZ) clinically-diagnosed seizures. Seizure outcome was categorized as uncontrolled, controlled on anti-seizure-medications(ASMs), or self-resolving if resolved without ASMs. Data were analyzed using Pearson's Chi-squared, Fisher Exact, or t-tests.

Of 317 FTD patients(average age of dementia onset=64.18+9.07years,46.37 % female]), 24(7.6 %) reported seizures. FTD+SZ were more likely to have anxiety(FTD+SZ=7(29.17 %),FTD-SZ= 35(11.95 %),p = 0.0392).Traumatic brain injury(TBI) was the only risk factor for seizures(FTD+SZ=6(25 %),FTD-SZ= 18(6 %),p < 0.001). BvFTD was the most common subtype in FTD+SZ(54.17 %). Focal seizures were more common(50 %) than generalized (29.17 %), with temporal-lobe epilepsy(TLE) being the most common subtype of focal seizures(42 %). Levetiracetam was the most frequently used ASM(38.1 %). Seizures had a favorable prognosis, with 87.5 % achieving seizure control through ASMs, and seizures self-resolving in the rest. FTD+SZ were more likely to be older at death(FTD+SZ=78.63years,FTD-SZ=71.37,p = 0.03966).

The prevalence of comorbid seizures in FTD at our single-center is 7.6 %. They were most common in bvFTD, primarily focal, with TLE as the predominant subtype. Anxiety was more prevalent with comorbid seizures. Most achieved seizure control on ASMs. FTD+SZ were older at death. These findings address a critical gap, guiding diagnosis, management, and future research.