This retrospective, single-center study investigated the risk factors, characteristics, and outcomes of seizures in frontotemporal dementia(FTD+SZ) compared to FTD without seizures(FTD-SZ).

 Seizures are associated with accelerated cognitive decline in dementia. Comorbid seizures are common in FTD, yet understudied. 

All patients coming to our hospital with clinically-diagnosed FTD from 2011-2024 were classified into 1)FTD+SZ) and2)FTD-SZ. FTD+SZ was defined as having any seizure observed. FTD was classified into behavioral-variant FTD(bvFTD),sematic-variant-primary-progressive aphasia(svPPA) or non-fluent-primary-progressive-aphasia(nfPPA).  Data on baseline demographics, seizure characteristics, and outcomes were obtained from EMR. Data were analyzed using Pearson’s Chi-squared test, fisher exact test, or t-tests.

Of 326 FTD patients(average age of dementia onset=64+9years, 46% female) who met the inclusion criteria, 10%(N=33) had seizures. The average age of seizure-onset was 63+13years in FTD+SZ. Traumatic brain injury(TBI) was the only significant risk factor for seizures in FTD(FTD+SZ=8 (24%) vs FTD-SZ=18(6%), p<0.001). All other characteristics were comparable among the groups. bvFTD was more prevalent in FTD+SZ compared to FTD-SZ(58% vs 50%). Of these, 16(48%) had epilepsy, seven (21%) had one-time unprovoked seizures, and seven(21%) had provoked seizures due to secondary causes.   Fourteen(42%) patients had focal-epilepsy, 11(33%) had generalized-epilepsy, and epilepsy type was unknown for the remaining 8(24%) patients.  Five(36 %) patients with focal epilepsy were diagnosed with temporal-lobe-epilepsy. For patients with focal epilepsy, 12(86%) patients had focal seizures with impaired awareness, 3(21%) of whom experienced secondary generalization. Twenty-five(76%) achieved control on ASMs and seizures self-resolved in the remaining 8(24%)FTD+SZ. 

Around 10% of FTD patients experience seizures. TBI was the most frequent risk factor associated with seizures in FTD. Seizures are more commonly associated with the behavioral variant of FTD. In FTD, focal epilepsy is most common, with temporal lobe epilepsy being the most prevalent subtype. The majority achieved seizure control. While not uncommon, seizures in FTD have a favorable outcome.