2023 American Academy of Neurology Abstract Website

Objective:

Taking advantage of a large autopsy series of uniformly pathologically-characterized persons with dementia (PWD), our goal was to determine the seizure occurrence rate for different types of pathologically confirmed dementia subtypes.

Background:

The incidence of seizures in PWD is higher than in persons without dementia. However, evidence of this is based on studies that included clinically-diagnosed all-cause dementia, pathologically-diagnosed Alzheimer’s Disease (AD), or clinically-diagnosed subtypes of dementia without pathological confirmation.

Design/Methods:

Retrospective review of clinical and autopsy records among all veterans who died while in a VA-based Special Dementia Care Unit and whose families consented to brain autopsy was conducted.

Results:

Of the 335 veterans, the majority (n = 327, 97.61%) were male with an average age of 78 years at death (SD=7.62). The average age at first reported symptom was 71 (SD=8.28). Overall, 57 (17%) veterans had evidence of new-onset seizures after the date of their dementia diagnosis and were thus considered to have dementia-related seizures. Of those with AD-only neuropathology (n=121), 26 (21.5%) had developed seizures and accounted for 45.6% of all the dementia-related seizure cases. In addition, most of the remaining cases of dementia-related seizures (n=26, 45.6%) showed evidence of AD pathology and in addition to another comorbid pathology. The remaining five (8.8%) were diagnosed with Frontotemporal Dementia and/or Traumatic Brain Injury.

Conclusions:

Dementia-related seizures are common and are associated with AD pathology. Even among pathologically mixed dementias, seizure prevalence was driven by AD pathology. Diagnosis of seizures in patients with dementia may reflect underlying AD pathology, regardless of clinical presentation. The development of dementia-related seizures should raise the possibility of underlying AD pathology and thus could have implications for treatment response.