High risk of developing subsequent epilepsy in young adults with migraine: a nationwide population-based cohort study in Taiwan

Bidirectional relationship between late-onset epilepsy (LOE) and dementia: A systematic review and meta-analysis of cohort studies

OBJECTIVE

To explore the bidirectional relationship of late-onset epilepsy (LOE) with dementia and Alzheimer's disease (AD).

METHODS

Using the common electronic databases, including PubMed, Cochrane Library databases and EMBASE, we systematically reviewed published cohort studies that assessed the risk of LOE in individuals comorbid with dementia or AD, and those with dementia or AD comorbid with LOE that had been published up to 31 March 2023. The data extraction process was carried out independently by two authors. The summary adjusted relative ratio (aRR) was calculated by employing Rev Man 5.3 for the inclusion of studies. To investigate the origins of heterogeneity, we conducted both subgroup and sensitivity analyses. In the presence of heterogeneity, a random-effects model was employed. To evaluate potential publication bias, we utilized the funnel plot and conducted Begg's and Egger's tests.

RESULTS

We included 20 eligible studies in the final analysis after a rigorous screening process. Pooled results indicated that LOE was association with an increased risk of all-cause dementia (aRR: 1.34, 95% confidence interval [CI]: 1.13-1.59) and AD (aRR: 2.49, 95% CI: 1.16-5.32). In addition, the pooled effect size for LOE associated with baseline AD and all-cause dementia were 3.51 (95% CI: 3.47-3.56) and 2.53 (95% CI: 2.39-2.67), respectively. Both sensitivity and subgroup analyses showed that these positive correlations persisted. According to the results of the Egger's and Begg's tests, as well as visual inspection of funnel plots, none of the studies appeared to be biased by publication.

CONCLUSION

The findings suggested that LOE is a potential risk factor for dementia and AD, and vice versa, dementia and AD are both potential risk indicators for LOE. Since there is substantial heterogeneity among the cohorts analyzed and more cohort studies should be conducted to confirm the correlations found in the current study.

Bi-directional associations of epilepsy with dementia and Alzheimer's disease: a systematic review and meta-analysis of longitudinal studies

OBJECTIVE

To assess the bi-directional associations of epilepsy with dementia and Alzheimer's disease (AD).

METHODS

We searched PubMed, Embase and the Cochrane Library for longitudinal studies assessing the associations of epilepsy with dementia and AD up to 4 August 2021. Two authors independently extracted study characteristics, exposures, outcomes and covariates. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled using a random effects model.

RESULTS

From 8,545 articles identified in the initial research, 27 publications describing 20 longitudinal studies were included in the final analyses. There were 10 studies on epilepsy predicting risk of dementia, 5 studies on epilepsy predicting risk of AD, 11 studies on dementia predicting risk of epilepsy, and 6 studies on AD predicting risk of epilepsy. Baseline epilepsy was associated with higher risk of dementia (pooled HR 2.00; 95% CI 1.73-2.33) and AD (pooled HR 1.81; 95% CI 1.19-2.75). The pooled HRs for epilepsy associated with baseline dementia and AD were 2.91 (95% CI) 2.11-4.01) and 3.11 (95% CI 2.47-3.90), respectively. These positive associations persisted in sensitivity and subgroup analyses.

CONCLUSIONS

Our findings suggested positive and bi-directional associations of epilepsy with dementia and AD. However, these associations should be carefully interpreted due to the presence of substantial heterogeneity, and they need to be verified in additional high-quality studies.

Bidirectional Relations Among Depression, Migraine, and Epilepsy: Do They Have an Impact on Their Response to Treatment?

The evaluation and treatment of patients with epilepsy is not limited to the type of epilepsy, but it must incorporate the common comorbid neurologic, psychiatric, and medical disorders, as the latter can bare an impact on the course and response to treatment of the seizure disorder and vice versa. In this article we review the bidirectional relations among epilepsy and two of its most common comorbidities, mood disorders and migraine and examine the implications of these relations on the selection of therapies of these three disorders and their response to treatment. We also review the most salient common pathogenic mechanisms that may explain such relations.

Headache in people with epilepsy

Epidemiological estimates indicate that individuals with epilepsy are more likely to experience headaches, including migraine, than individuals without epilepsy. Headaches can be temporally unrelated to seizures, or can occur before, during or after an episode; seizures and migraine attacks are mostly not temporally linked. The pathophysiological links between headaches (including migraine) and epilepsy are complex and have not yet been fully elucidated. Correct diagnoses and appropriate treatment of headaches in individuals with epilepsy is essential, as headaches can contribute substantially to disease burden. Here, we review the insights that have been made into the associations between headache and epilepsy over the past 5 years, including information on the pathophysiological mechanisms and genetic variants that link the two disorders. We also discuss the current best practice for the management of headaches co-occurring with epilepsy and highlight future challenges for this area of research.

Association Between Migraine Headaches and Dementia in More than 7,400 Patients Followed in General Practices in the United Kingdom

BACKGROUND

Most previous studies focusing on the migraine headache-dementia relationship have failed to simultaneously adjust for several common comorbidities.

OBJECTIVE

The goal of this retrospective cohort study was to investigate the association between migraine headaches and dementia in general practices in the UK.

METHODS

The current study sample included patients who received a migraine diagnosis in one of 67 general practices in the UK between January 1997 and December 2016 (index date). Patients without migraine diagnoses were matched 1 : 1 to patients with migraine diagnoses based on propensity scores using a greedy algorithm and derived from the logistic regression using age, sex, index year, and co-diagnoses. The main outcome of the study was the association between migraine headaches and the incidence of dementia within 10 years of the index date.

RESULTS

This study included 7,454 individuals with or without migraine diagnoses. Mean age was 67.7 years (SD = 5.8 years), and 72.9% of patients were women. Within 10 years of the index date, 5.2% of participants with and 3.7% of those without migraine headaches were diagnosed with dementia (log-rank p < 0.001). The respective figures were 5.8% and 3.6% in women (log-rank p < 0.001) and 4.5% and 3.4% in men (log-rank p = 0.722). We observed a positive association between migraine diagnoses and all-cause dementia (hazard ratio [HR] = 1.43) as well as Alzheimer's disease (HR = 1.87). Sensitivity analyses further revealed that these associations were only significant in women (all-cause dementia: HR = 1.65; Alzheimer's disease: HR = 2.27).

CONCLUSION

Migraine diagnoses were positively associated with all-cause dementia and Alzheimer's disease in women.

Ventrolateral Periaqueductal Gray Matter Neurochemical Lesion Facilitates Epileptogenesis and Enhances Pain Sensitivity in Epileptic Rats

The ventrolateral periaqueductal gray matter (vlPAG) plays a critical role in the pathogenesis of migraine and few studies have shown that vlPAG might be involved in the pathophysiology of epilepsy. But its roles in epileptogenesis and comorbid relationship between migraine and epilepsy have never been reported. In this study, the impairments of vlPAG neuronal network during spontaneous recurrent seizure (SRS) development after status epilepticus (SE) were investigated, and the pain sensitivity as well as the SRS investigated after neurochemical lesion to vlPAG to determine the role of vlPAG in epileptogenesis and in migraine comorbidity with epilepsy. Neuronal loss and alterations of excitatory and inhibitory neural transmission within vlPAG accompanied the development of epileptogenesis induced by SE. On the other hand, neurochemical lesion to vlPAG enhanced frequency and duration of spontaneous seizure event and frequency of epileptiform inter-ictal spike discharges in electroencephalography (EEG), but decreased pain threshold in epileptic rats. This indicates an involvement of the pain regulating structure, vlPAG, in the pathogenesis of epilepsy. This may imply that vlPAG network alterations could be a possible underlying mechanism of the interactive comorbid relationship between epilepsy and migraine.

Bidirectional relations among common psychiatric and neurologic comorbidities and epilepsy: Do they have an impact on the course of the seizure disorder?

The treatment of epilepsy is not limited to the achievement of a seizure‐free state. It must also incorporate the management of common psychiatric and neurologic comorbidities, affecting on average between 30 and 50% of patients with epilepsy, which have a significant impact on their lives at various levels, including quality of life and the prognosis of the seizure disorder. Mood and anxiety disorders are the most frequent psychiatric comorbidities, whereas stroke and migraine are among the more common neurologic comorbidities, migraine among the younger patients and stroke among the older patients. Not only do these psychiatric and neurologic comorbidities each have a bidirectional relation with epilepsy, but primary mood disorders have a bidirectional relation with these 2 neurologic disorders. Furthermore, depression and migraine have been each associated with a more severe epilepsy course, whereas depression has been associated with a more severe course of stroke and migraines. The purpose of this article is to review the clinical implications of the complex relations among epilepsy and these 3 comorbid disorders, and to identify any clinical and/or experimental evidence that may suggest that having more than one of these comorbid disorders may increase the risk of and course of epilepsy.

High risk of developing subsequent epilepsy in patients with sleep-disordered breathing

Purpose

Sleep-disordered breathing (SDB) is often associated with other medical disorders. Whether SDB interacts with other factors for developing subsequent epilepsy remains unclear.

Methods

This population-based cohort study was conducted using the National Health Insurance Research Database of Taiwan. Patients aged >20 years and diagnosed with SDB between 2000 and 2010 comprised the SDB cohort (n = 138,507), and their data were compared with those of the comparison cohort (n = 138,507). The adjusted hazard ratio (aHR) for epilepsy was calculated using a multivariate Cox proportional hazards model.

Results

The SDB cohort had an increased risk of epilepsy (aHR = 1.50, 95% confidence interval [CI] = 1.36–1.66). The sex-stratified analysis revealed a significant adjusted hazard ratio (aHR) for epilepsy with a 1.51-fold higher risk for female patients, and also a significantly 1.49-fold higher risk for male patients in the SDB cohort. Although epilepsy incidence increased with age in both cohorts, different age groups in the SDB cohort all had a significantly higher risk of developing epilepsy than comparison cohort.

Conclusion

This population-based cohort study indicates that patients with SDB are at a high risk of developing subsequent epilepsy, in both sexes and all age groups.

Headaches and Risk of Dementia

BACKGROUND

Primary headaches include migraines, tension-type headaches and other primary headache syndromes. Migraines and tension-type headaches are associated with patient discomfort and other diseases. This study aimed to investigate the association between primary headaches and the risk of developing dementia, and to clarify the association between different types of headaches and dementia.

MATERIALS AND METHODS

We conducted a nationwide matched cohort population-based study. A total of 3,620 patients with newly diagnosed primary headaches, including migraines and tension-type headaches, between January 1 and December 31, 2000 were selected from the National Health Insurance Research Database of Taiwan, along with 10,860 controls matched for sex and age. After adjusting for confounding factors, Fine and Gray׳s competing risk analysis was used to compare the risk of developing dementia during 10 years of follow-up.

RESULTS

Of the study subjects, 170 (4.70 %) developed dementia compared with 433 (3.99%) of the controls. Fine and Gray׳s competing risk analysis revealed that the study subjects were more likely to develop dementia (hazard ratio = 2.057; 95% CI: 1.718-2.462; P < 0.001). After adjusting for sex, age, monthly income, urbanization level, geographic region of residence and comorbidities, the hazard ratio for dementia was 2.048 (95% CI: 1.705-2.461, P < 0.001). Migraines and tension-type headaches were associated with nonvascular dementia but not vascular dementia.

CONCLUSIONS

The patients with headaches had a 105% increased risk of dementia. Further studies are needed to elucidate the underlying mechanisms.

Male, old age and low income to predispose epilepsy in migraineurs

BACKGROUND

This study investigated whether sex, age, income and any comorbidity affect subsequent epilepsy development in migraineurs.

MATERIALS AND METHODS

A total of 4915 men diagnosed with migraine who were aged older than 20 years were identified as the study cohort. A total of 4882 female migraineurs were included in the comparison cohort. We calculated the adjusted hazard ratio (aHR) for the risk of epilepsy in the two cohorts after adjustment for age and comorbidity. Kaplan-Meier analysis was used to analyse the cumulative epilepsy incidence, and the log-rank test was used to estimate the differences between the two cumulative incidence curves.

RESULTS

The risk of epilepsy was 2·31-fold higher in male migraineurs than in female migraineurs. The income-specific analysis showed that the risk of epilepsy was high in migraineurs with a low monthly income [aHR: 2·73 for 15 000-25 000 new Taiwan dollar (NTD; approximately 500-833 USD) and aHR: 2·71 for < 15 000 NTD]. Among patients with one or more comorbidity, a 2·48-fold (95% confidence interval: 1·65-3·74) high risk of epilepsy was noted in male migraineurs, regardless of the presence of head injury. Additional analyses revealed that male migraineurs aged 65 years or older had the highest risk of epilepsy.

CONCLUSION

Migraineurs have an increased risk of subsequent epilepsy. Male sex, old age and low income may interact with migraine and result in a high risk of epilepsy in migraineurs.

Patients with psychogenic nonepileptic seizures report more severe migraine than patients with epilepsy

PURPOSE

Clinical observations suggest that psychogenic non-epileptic seizure (PNES) patients often have severe migraine, more severe than epilepsy patients. Investigations into migraine characteristics in patients with PNES are lacking. In this study we tested the hypothesis that, compared to epilepsy patients, PNES patients have more severe migraine, with more frequent and longer duration attacks that cause greater disability.

METHOD

In this observational study, 633 patients with video-EEG proven epilepsy or PNES were identified from the Mayo Clinic Epilepsy Monitoring Unit database. Contacted patients were screened for migraine via a validated questionnaire, and when present, data regarding migraine characteristics were collected. Two-sample t-tests, chi square analyses, and Mann-Whitney U tests were used to compare migraine characteristics in PNES patients to those of epilepsy patients.

RESULTS

Data from 43 PNES patients with migraine and 29 epilepsy patients with migraine were available. Compared to epilepsy patients, PNES patients reported having more frequent headaches (mean 15.1 ± 9.8 vs. 8.1 ± 6.6 headache days/month, p<.001), more frequent migraine attacks (mean 6.5 ± 6.3 vs. 3.8. ± 4.1 migraines/month, p=.028), longer duration migraines (mean 39.5 ± 28.3 vs. 27.3 ± 20.1h, p=.035), and more frequently had non-visual migraine auras (78.6% vs. 46.7% of patients with migraine auras, p=.033). Migraine-related disability scores were not different between PNES and epilepsy patients (median 39, interquartile range 89 vs. 25, interquartile range 60.6, p=.15).

CONCLUSION

Compared to epilepsy patients with migraine, PNES patients with migraine report having a more severe form of migraine with more frequent and longer duration attacks that are more commonly associated with non-visual migraine auras.