Temporal lobe epilepsy in the elderly

Psychosis as a Manifestation of Focal Impaired Awareness Seizure in a Geriatric Patient

Focal impaired awareness seizures (FIAS), previously known as complex partial seizures, refer to focal seizures that start in one hemisphere of the brain and are associated with an impairment in consciousness. FIAS of temporal lobe origin most often present with psychopathology, such as behavioral and affective symptoms. It has a bimodal age distribution peaking at the extremes of life. Geriatric presentations can often be subtle and go unnoticed asides from a few symptoms, such as confusion and memory lapses. Here, we present a unique case of a geriatric patient with FIAS presenting as transient psychosis.

Atrophy and cognitive profiles in older adults with temporal lobe epilepsy are similar to mild cognitive impairment

Epilepsy incidence and prevalence peaks in older adults yet systematic studies of brain ageing and cognition in older adults with epilepsy remain limited. Here, we characterize patterns of cortical atrophy and cognitive impairment in 73 older adults with temporal lobe epilepsy (>55 years) and compare these patterns to those observed in 70 healthy controls and 79 patients with amnestic mild cognitive impairment, the prodromal stage of Alzheimer's disease. Patients with temporal lobe epilepsy were recruited from four tertiary epilepsy surgical centres; amnestic mild cognitive impairment and control subjects were obtained from the Alzheimer's Disease Neuroimaging Initiative database. Whole brain and region of interest analyses were conducted between patient groups and controls, as well as between temporal lobe epilepsy patients with early-onset (age of onset <50 years) and late-onset (>50 years) seizures. Older adults with temporal lobe epilepsy demonstrated a similar pattern and magnitude of medial temporal lobe atrophy to amnestic mild cognitive impairment. Region of interest analyses revealed pronounced medial temporal lobe thinning in both patient groups in bilateral entorhinal, temporal pole, and fusiform regions (all P < 0.05). Patients with temporal lobe epilepsy demonstrated thinner left entorhinal cortex compared to amnestic mild cognitive impairment (P = 0.02). Patients with late-onset temporal lobe epilepsy had a more consistent pattern of cortical thinning than patients with early-onset epilepsy, demonstrating decreased cortical thickness extending into the bilateral fusiform (both P < 0.01). Both temporal lobe epilepsy and amnestic mild cognitive impairment groups showed significant memory and language impairment relative to healthy control subjects. However, despite similar performances in language and memory encoding, patients with amnestic mild cognitive impairment demonstrated poorer delayed memory performances relative to both early and late-onset temporal lobe epilepsy. Medial temporal lobe atrophy and cognitive impairment overlap between older adults with temporal lobe epilepsy and amnestic mild cognitive impairment highlights the risks of growing old with epilepsy. Concerns regarding accelerated ageing and Alzheimer's disease co-morbidity in older adults with temporal lobe epilepsy suggests an urgent need for translational research aimed at identifying common mechanisms and/or targeting symptoms shared across a broad neurological disease spectrum.

Epilepsy Among Elderly Medicare Beneficiaries: A Validated Approach to Identify Prevalent and Incident Epilepsy

BACKGROUND

Uncertain validity of epilepsy diagnoses within health insurance claims and other large datasets have hindered efforts to study and monitor care at the population level.

OBJECTIVES

To develop and validate prediction models using longitudinal Medicare administrative data to identify patients with actual epilepsy among those with the diagnosis.

RESEARCH DESIGN, SUBJECTS, MEASURES

We used linked electronic health records and Medicare administrative data including claims to predict epilepsy status. A neurologist reviewed electronic health record data to assess epilepsy status in a stratified random sample of Medicare beneficiaries aged 65+ years between January 2012 and December 2014. We then reconstructed the full sample using inverse probability sampling weights. We developed prediction models using longitudinal Medicare data, then in a separate sample evaluated the predictive performance of each model, for example, area under the receiver operating characteristic curve (AUROC), sensitivity, and specificity.

RESULTS

Of 20,945 patients in the reconstructed sample, 2.1% had confirmed epilepsy. The best-performing prediction model to identify prevalent epilepsy required epilepsy diagnoses with multiple claims at least 60 days apart, and epilepsy-specific drug claims: AUROC=0.93 [95% confidence interval (CI), 0.90-0.96], and with an 80% diagnostic threshold, sensitivity=87.8% (95% CI, 80.4%-93.2%), specificity=98.4% (95% CI, 98.2%-98.5%). A similar model also performed well in predicting incident epilepsy (k=0.79; 95% CI, 0.66-0.92).

CONCLUSIONS

Prediction models using longitudinal Medicare data perform well in predicting incident and prevalent epilepsy status accurately.

Epilepsy in the elderly: Special considerations and challenges

The elderly are generally defined as those over 60 or 65 years old, but they are a heterogeneous group and may be subdivided into categories based on age and health status. The incidence of epilepsy is highest in the elderly. With a progressive increase in life expectancy, this is the fastest growing segment of patients with epilepsy. Older patients most often have focal seizures, with less prominent auras and automatisms, and longer duration of postictal confusion compared to younger patients. Status epilepticus is common and has a high mortality. The most common specific etiology is cerebrovascular disease, but the cause remains unknown in many patients. Diagnosis can be challenging because of several patient-related, physician-related and investigation-related factors. Over-diagnosis and under-diagnosis are common. Treatment is complicated by the presence of physiological changes related to aging, co-morbidities and cognitive problems as well as concerns regarding drug interactions and medication adherence. Seizures can be controlled in most patients with low doses of a single anti-epileptic drug (AED). Tolerability is an important factor in selection of an AED, as elderly patients tend to be highly sensitive to side effects. Drug-resistant epilepsy is uncommon. Epilepsy surgery, especially temporal lobectomy, can be performed in older patients with good results. More studies addressing the pathophysiological mechanisms of epilepsy in this age group, and greater inclusion of the elderly in clinical trials, as well as development of comprehensive care models are needed to provide optimal care to these patients.