Diagnosing cognitive disorders in older adults with epilepsy

Abstract

Objective To characterize the nature and prevalence of cognitive disorders in older adults with temporal lobe epilepsy (TLE) and compare their cognitive profiles to patients with amnestic mild cognitive impairment (ie, aMCI). Methods Seventy‐one older patients with TLE, 77 aMCI, and 69 normal aging controls (NACs), all 55‐80 years of age, completed neuropsychological measures of memory, language, executive function, and processing speed. An actuarial neuropsychological method designed to diagnose MCI was applied to individual patients to identify older adults with TLE who met diagnostic criteria for MCI (TLE‐MCI). A linear classifier was performed to evaluate how well the diagnostic criteria differentiated patients with TLE‐MCI from aMCI. In TLE, the contribution of epilepsy‐related and vascular risk factors to cognitive impairment was evaluated using multiple regression. Results Forty‐three TLE patients (60%) met criteria for TLE‐MCI, demonstrating marked deficits in both memory and language. When patients were analyzed according to age at seizure onset, 63% of those with an early onset (<50 years) versus 56% of those with late onset (≥ 50 years) met criteria for TLE‐MCI. A classification model between TLE‐MCI and aMCI correctly classified 81.1% (90.6% specificity, 61.3% sensitivity) of the cohort based on neuropsychological scores. Whereas TLE‐MCI showed greater deficits in language relative to aMCI, patients with aMCI showed greater rapid forgetting on memory measures. Both epilepsy‐related risk factors and the presence of leukoaraiosis on MRI contributed to impairment profiles in TLE‐MCI. Significance Cognitive impairment is a common comorbidity in epilepsy and it presents in a substantial number of older adults with TLE. Although the underlying etiologies are unknown in many patients, the TLE‐MCI phenotype may be secondary to an accumulation of epilepsy and vascular risk factors, signal the onset of a neurodegenerative disease, or represent a combination of factors.

Breaking the Seizure Randomness Myth: Evidence for a Recurring Ebb and Flow of Seizure Risk on the Continuum of Time

“…Circadian seizure cycles were noted in 89% (76/85) PWE, similar to the prevalence reported in studies from NeuroVista and Seizure-Tracker, a self-reported seizure diary. 8 Multidien seizure cycles were noted in 60% (112/186) of PWE. The multidien cycles did not align with fixed period lengths such as the day of the week, month, or lunar phase, highlighting the unlikely influence of external or environmental cues and their likely governance by endogenous factors.…”

“…However, the prevalence of multidien seizure cycle is equal in men and women in the current and another recent study. 8 Although hormones such as testosterone, cortisol, and aldosterone have multidien fluctuations, we are far from understanding their interactions with the multidien seizure cycles. In contrast, moving from systemic influences on seizure cycles to inherent brain mechanisms provides tempting and concrete evidence for drivers of the multidien seizure cycles in the form of interaction of IEAs and seizures.…”

Mechanisms Involved in Epileptogenesis in Alzheimer’s Disease and Their Therapeutic Implications

“…Cognitive impairment is a common finding in epilepsy, including late-onset epilepsy [20,84]. Indeed, multiple studies support a higher prevalence of mild cognitive impairment (MCI) in late-onset epilepsy (40-55%) [75,85] and in temporal lobe epilepsies (TLE) in which prevalence is up 60% [84]. The amount of temporomedial IEDs and hippocampal onset seizures correlate with progressive episodic memory decline in TLE [20,78,86].…”

Modifiable Risk Factors of Dementia in Older Adults With Epilepsy: An Opportunity to Flatten the Curve?

“…A recent study in older adults (age ≥55 years) with temporal lobe epilepsy found that after controlling epilepsy-related clinical variables, leukoaraiosis on MRI remained significantly associated with poorer memory performance. 8 A definitive evidence for advocating aggressive management of cerebrovascular and lifestyle risk factors to prevent dementia in older PWE is beyond our immediate scientific horizon. However, the emerging evidence in epilepsy research and the extrapolation from dementia literature suggests that our patients will be better served by us taking a proactive stance in managing the modifiable dementia risk factors, in addition to improved seizure control.…”