Factors associated with subjective cognitive function in epilepsy and psychogenic non-epileptic seizures

Neurocognitive performance in functional neurological disorder: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Cognitive complaints are common in functional neurological disorder (FND), but it is unclear whether objective neurocognitive deficits are present. This systematic review summarized validated/standardized cognitive test performance in FND samples across cognitive domains.

METHODS

Embase, PsycInfo and MEDLINE were searched from inception to 15 May 2023, combining terms for FND and cognitive domains (e.g., attention, memory, executive functioning). Studies included a range of FND phenotypes (seizures, motor, cognitive disorder, mixed), compared to healthy or clinical controls. Risk of bias was assessed with the modified Newcastle-Ottawa Scale and a qualitative synthesis/narrative review of cognitive performance in FND was conducted. Test performance scores were extracted, and random effects meta-analyses were run where appropriate. This review was registered on PROSPERO, CRD42023423139.

RESULTS

Fifty-six studies including 2260 individuals with FND were eligible. Although evidence for some impairments emerged across domains of executive functioning, attention, memory and psychomotor/processing speed, this was inconsistent across studies and FND phenotypes. Common confounds included group differences in demographics, medication and intellectual functioning. Only 24% of studies objectively assessed performance validity. Meta-analyses revealed higher scores on tests of naming (g = 0.67, 95% confidence interval [CI] 0.50, 0.84) and long-term memory (g = 0.43, 95% CI 0.13, 0.74) in functional seizures versus epilepsy, but no significant differences in working (g = -0.08, 95% CI -0.44, 0.29) or immediate (g = 0.25, 95% CI -0.02, 0.53) memory and cognitive flexibility (g = -0.01, 95% CI -0.29, 0.28).

CONCLUSIONS

There is mixed evidence for objective cognitive deficits in FND. Future research should control for confounds, include tests of performance validity, and assess relationships between objective and subjective neurocognitive functioning.

Reduced Subjective Cognitive Concerns With Neurobehavioral Therapy in Functional Seizures and Traumatic Brain Injury

OBJECTIVE

Functional seizures are common among people with traumatic brain injury (TBI). Subjective cognitive concerns refer to a person's own perception of problems with cognitive functioning in everyday life. The authors investigated the presence and correlates of subjective cognitive concerns and the response to neurobehavioral therapy among adults with TBI and functional seizures (TBI+FS group).

METHODS

In this observational study, participants in the TBI+FS group (N=47) completed a 12-session neurobehavioral therapy protocol for seizures, while participants in the comparison group (TBI without seizures) (N=50) received usual treatment. Subjective cognitive concerns, objective cognition, mental health, and quality of life were assessed before and after treatment. Data collection occurred from 2018 to 2022.

RESULTS

Baseline subjective cognitive concerns were reported for 37 (79%) participants in the TBI+FS group and 20 (40%) participants in the comparison group. In a multivariable regression model in the TBI+FS group, baseline global mental health (β=-0.97) and obsessive-compulsive symptoms (β=-1.01) were associated with subjective cognitive concerns at baseline. The TBI+FS group had fewer subjective cognitive concerns after treatment (η2=0.09), whereas the TBI comparison group showed a nonsignificant increase in subjective cognitive concerns.

CONCLUSIONS

Subjective cognitive concerns are common among people with TBI and functional seizures and may be related to general mental health and obsessive-compulsive symptoms. Evidence-based neurobehavioral therapy for functional seizures is a reasonable treatment option to address such concerns in this population, although additional studies in culturally diverse samples are needed. In addition, people with functional seizures would likely benefit from rehabilitation specifically targeted toward cognitive functioning.

Influence of psychological factors on the relationship between subjective and objective memory in adults with pharmacoresistant temporal lobe epilepsy

PURPOSE

Many adults with temporal lobe epilepsy (TLE) report subjective cognitive impairment; however, prior studies have shown a discrepancy between these subjective complaints and objective cognitive deficits on neuropsychological measures. Mood disorders/symptoms are also common in TLE and have been linked to greater subjective cognitive difficulties. To further understand these relationships, this retrospective study sought to determine if symptoms of depression and anxiety moderate or mediate the relationship between subjective cognitive impairment and objective cognitive performance in adults with TLE.

METHOD

Participants were 345 adults (mean age = 40.7; 55 % female) with pharmacoresistant TLE who completed self-report screening measures of depression, anxiety, and subjective cognitive function along with objective memory measures as part of a pre-surgical clinical neuropsychological evaluation. A series of linear regression analyses was conducted to examine the potential moderating and mediating effects of mood on the relationship between subjective and objective memory function after adjusting for relevant covariates.

RESULTS

Consistent with existing literature, self-reported depression and anxiety symptoms were significantly correlated with subjective memory difficulties across all scales (all p < .001). Subjective memory impairment was also significantly correlated with objective memory performance on neuropsychological measures, albeit with small effect sizes (estimate range 0.04-0.20). Contrary to our hypothesis, depression and anxiety did not moderate or mediate the relationship between subjective memory complaints and objective memory performance.

CONCLUSIONS

While symptoms of depression and anxiety were associated with subjective memory ability in this cohort of adults with TLE, this study suggests that mood symptoms do not fully explain the relationship between subjective and objective memory function, likely reflecting the complex and multifactorial relationships among these variables. Nevertheless, our results highlight the importance of screening for depression and anxiety symptoms and assessing patients' subjective memory complaints as part of a neuropsychological evaluation as each of these factors tap into a different aspect of the patient functioning.

Improvements in Montreal Cognitive Assessment scores after neurobehavioral therapy in adults with functional (nonepileptic) seizures and traumatic brain injury

Cognitive functioning impacts clinical symptoms, treatment response, and quality of life in adults with functional/nonepileptic seizures (FS/NES), but no study to date examines effects of behavioral FS/NES treatment on cognition in these patients. We hypothesized that there would be a reduction in cognitive symptoms in participants with FS/NES and traumatic brain injury (TBI) following neurobehavioral therapy (NBT). We also hypothesized that select seizure-related, medication, subjective cognitive, and mental health symptoms would be negatively correlated with improvements in cognitive performance after NBT. Participants were 37 adults with TBI + FS/NES and 35 adults with TBI only, recruited from medical centers in the northeastern or southeastern U.S. TBI + FS/NES participants completed a 12 session NBT intervention, and TBI without seizures participants were not treated. All participants completed pre-post assessments of cognition (Montreal Cognitive Assessment [MoCA]) and baseline sociodemographic factors and mental health symptoms. Pre-post MoCA scores increased significantly in TBI + FS/NES participants (28/37 [75.7%] improved) but not in TBI comparisons (10/35 [28.6%] improved). Language, memory, and visuospatial/executive functions, but not attention, improved over time in the TBI + FS/NES group. Gains in cognition were concentrated in those TBI + FS/NES participants with likely baseline cognitive impairments (MoCA total score <26), and 9/17 of these participants moved from the "impaired" range at baseline (<26) to the "intact" range at endpoint (≥26). Lastly, participants taking fewer medications and reporting lower subjective cognitive difficulties at baseline showed larger pre-post MoCA total score improvements. Overall, results from this study suggest the potential for positive change in cognition in FS/NES and co-occurring TBI using evidence-based psychotherapy.

Influence of comorbidity on mortality in patients with epilepsy and psychogenic nonepileptic seizures

OBJECTIVE

This study aims to determine the contribution of comorbidities to excess psychogenic nonepileptic seizures (PNES) mortality.

METHODS

A retrospective cohort study was conducted of tertiary epilepsy outpatients from St. Vincent's Hospital Melbourne, Australia with an 8:1 comparison cohort, matched by age, sex, and socioeconomic status (SES) to national administrative databases between 2007 and 2017. Privacy-preserving data linkage was undertaken with the national prescription, National Death Index, and National Coronial Information System. Forty-five comorbid disease classes were derived by applying the Australian validated RxRisk-V to all dispensed prescriptions. We fitted Cox proportional hazard models controlling for age, sex, SES, comorbidity, disease duration, and number of concomitant antiseizure medications, as a marker of disease severity. We also performed a parallel forward-selection change in estimate strategy to explore which specific comorbidities contributed to the largest changes in the hazard ratio.

RESULTS

A total of 13 488 participants were followed for a median 3.2 years (interquartile range = 2.4-4.0 years), including 1628 tertiary epilepsy outpatients, 1384 patients with epilepsy, 176 with PNES, and 59 with both. Eighty-two percent of epileptic seizures and 92% of typical PNES events were captured in an epilepsy monitoring unit. The age-/sex-/SES-adjusted hazard ratio was elevated for epilepsy (4.74, 95% confidence interval [CI] = 3.36-6.68) and PNES (3.46, 95% CI = 1.38-8.68) and remained elevated for epilepsy (3.21, 95% CI = 2.22-4.63) but not PNES (2.15, 95% CI = .77-6.04) after comorbidity adjustment. PNES had more pre-existing comorbidities (p = .0007), with a three times greater median weighted Rx-RiskV score. Psychotic illness, opioid analgesia, malignancies, and nonopioid analgesia had the greatest influence on PNES comorbid risk.

SIGNIFICANCE

Higher comorbidity appears to explain the excess PNES mortality and may represent either a wider underrecognized somatoform disorder or a psychological response to physical illness. Better understanding and management of the bidirectional relationship of these wider somatic treatments in PNES could potentially reduce the risk of death.

Neuropsychological performance and effort in patients diagnosed with psychogenic nonepileptic seizures - Descriptive study of a Czech sample

PURPOSE

The aim of the study was to examine the neuropsychological performance and effort in patients with a confirmed PNES diagnosis. The second aim of the study was to investigate the relationship between validity indicators from the cognitive battery with validity and clinical scales from a personality scale.

METHOD

Patients with PNES (N = 250; F:M 186:64; mean age 38.32 (13.23)) were assessed utilizing the RBANS (Czech Research version) to evaluate cognitive performance and to obtain the Effort Index. The MMPI-2 was used to evaluate personality and psychopathology.

RESULTS

Global cognitive performance was 0.92 SD below average (according to the Gaussian distribution) in patients with PNES. The lowest scores in the sample were in the Attention domain (-1.7SD). Insufficient effort was detected in 10% of patients. Education correlated negatively with the Effort index (rs = -0.25, p = 0.01). A mild significant correlation in Scale 7 (rs = 0.21, p = 0.01) and Scale 8 (rs = 0.24, p = 0.01), and a significant correlation between Effort Index and Back F Scale (rs = 0.23, p = 0.01) were noted.

CONCLUSIONS

Assessment of cognitive performance and effort is an essential part of the comprehensive evaluation of patients with PNES during their hospitalization at Epilepsy centers. Many aspects of the neuropsychological assessment can offer useful indications for reaching a differential diagnosis, including clinical history, behavioral observations, cognitive and symptom validity testing, and structured psychological inventories.

Functional seizures are not less important than epilepsy

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People with functional seizures often suffer from psychiatric comorbidities.

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People with FS report detrimental effects on social aspects of their lives.

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FS are associated with a considerable direct and indirect economic burden.

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FS have increased rates of mortality compared to healthy controls.

Functional seizures (FS) are frequently encountered in neurology clinics, often affect young adults, and have significant negative impacts on many aspects of a person’s life. In the current narrative review, we searched the literature regarding some of the consequences of FS (i.e., psychiatric comorbidities, social consequences, costs that are associated with the condition, cognitive impairment in patients with FS, the quality of life of the people with FS, and the increased risk of mortality that is associated with FS). Evidence shows that FS have significant negative consequences, comparable in their magnitude to those affecting patients with epilepsy. The clinical and scientific communities should take steps to address these consequences through clinical care and research that prioritizes, facilitates, and expedites evidence-based diagnosis and treatment for FS.

Adverse events related to antiepileptic drugs

OBJECTIVE

Adverse events (AEs) related to antiepileptic drugs (AEDs) may interfere with adequate dosing and patient adherence, leading to suboptimal seizure control, and relatedly, increased injuries, hospitalizations, and mortality. This study investigated the clinicodemographic factors associated with AEs related to AEDs as reported by the Liverpool Adverse Events Profile (LAEP), and explored the ability of LAEP to discriminate between epilepsy and psychogenic nonepileptic seizures (PNES). We hypothesized that female sex, mood disorders, AED-polytherapy, duration, and severity of epilepsy are associated with increased endorsement of AEs related to AEDs, and that endorsement of AEs related to AEDs would significantly differ between epilepsy and PNES patients.

METHODS

We prospectively enrolled adult patients admitted to two inpatient video-electroencephalogram monitoring units. Clinicodemographic variables and psychometric measures of depression, anxiety, and cognitive function were recorded. Patient-reported AE endorsement was obtained using the LAEP, which was reduced to four latent domains using exploratory structural equation modeling. General linear models identified variables associated with each domain. Logistic regression determined the ability of LAEP scores to differentiate between epilepsy and PNES.

RESULTS

311 patients met inclusion criteria. Mean age was 38 years and 56% of patients were female. Network analysis demonstrated strong relationships between depression and anxiety with physical, sleep, psychiatric, and dermatological AE endorsement. Depression, female sex, and AED polytherapy were associated with greater AE endorsement. Epilepsy, compared to PNES, was associated with lower AE endorsement. Fewer prescribed AEDs and greater reported physical AE endorsement were associated with PNES diagnosis.

SIGNIFICANCE

There is a strong relationship between patient-reported AEs and psychiatric symptomatology. Those with PNES paradoxically endorse greater physical AEs despite receiving fewer AEDs. Patients who endorse AEs in clinical practice should be screened for comorbid depression or anxiety and treated accordingly.