Treatment of epilepsy for people with Alzheimer's disease

Tackling seizures in patients with Alzheimer's disease

INTRODUCTION

In past years, a possible bidirectional link between epilepsy and Alzheimer's disease (AD) has been proposed: if AD patients are more likely to develop epilepsy, people with late-onset epilepsy evidence an increased risk of dementia. Furthermore, current research suggested that subclinical epileptiform discharges may be more frequent in patients with AD and network hyperexcitability may hasten cognitive impairment.

AREAS COVERED

In this narrative review, the authors discuss the recent evidence linking AD and epilepsy as well as seizures semeiology and epileptiform activity observed in patients with AD. Finally, anti-seizure medications (ASMs) and therapeutic trials to tackle seizures and network hyperexcitability in this clinical scenario have been summarized.

EXPERT OPINION

There is growing experimental evidence demonstrating a strong connection between seizures, neuronal hyperexcitability, and AD. Epilepsy in AD has shown a good response to ASMs both at the late and prodromal stages. The new generation ASMs with fewer cognitive adverse effects seem to be a preferable option. Data on the possible effects of network hyperexcitability and ASMs on AD progression are still inconclusive. Further clinical trials are mandatory to identify clear guidelines about treatment of subclinical epileptiform discharges in patients with AD without seizures.

Levetiracetam attenuates diabetes-associated cognitive impairment and microglia polarization by suppressing neuroinflammation

Introduction: Cognitive impairment is a common complication and comorbidity of diabetes. However, the underlying mechanisms of diabetes-associated cognitive dysfunction are currently unclear. M1 microglia secretes pro-inflammatory factors and can be marked by CD16, iNOS, Iba1 and TNF-ɑ. The decline of M2 microglia in the diabetic rats indicates that high glucose promotes the differentiation of microglia into the M1 type to trigger neuroinflammatory responses. Moreover, there is a lack of strong evidence for treatments of diabetes-associated cognitive impairment in addition to controlling blood glucose. Methods: Diabetic rats were established by intraperitoneal injection of one dose of streptozotocin (60 mg/kg). Polarization transitions of microglia were induced by high glucose treatment in BV2 cells. Levetiracetam was orally administered to rats 72 h after streptozotocin injection for 12 weeks. Results: In STZ-induced diabetic rats, the results demonstrated that levetiracetam improved rat cognitive function (Morris water maze test) and hippocampus morphology (Hematoxylin-eosin staining), and the effect was more evident in the high-dose levetiracetam group. Microglia activation in the hippocampus was inhibited by levetiracetam treatment for 12 weeks. Serum levels of TNF-α, IL-1β, and IL-6 were reduced in the LEV-L and LEV-H groups, and IL-1β level was obviously reduced in the LEV-H group. In vitro, we found that levetiracetam 50 µM attenuated high-glucose induced microglial polarization by increasing IL-10 level and decreasing IL-1β and TNF-α levels. Moreover, levetiracetam 50 µM increased and decreased the proportion of CD206+/Iba1+ and iNOS+/Iba1+cells, respectively. Western blot analysis illustrated that LEV 50 µM downregulated the expression of MyD88 and TRAF6, and phosphorylation of TAK1, JNK, p38, and NF-κB p65. The effect of levetiracetam on the anti-polarization and expression of p-JNK and p-NF-κB p65 were partly reversed by anisomycin (p38 and JNK activators). Discussion: Together, our data suggest that levetiracetam attenuates streptozotocin-induced cognitive impairment by suppressing microglia activation. The in vitro findings also indicate that the levetiracetam inhibited the polarization of microglia via the JNK/MAPK/NF-κB signaling pathway.

A peptide blocking the ADORA1-neurabin interaction is anticonvulsant and inhibits epilepsy in an Alzheimer's model

Epileptic seizures are common sequelae of stroke, acute brain injury, and chronic neurodegenerative diseases, including Alzheimer's disease (AD), and cannot be effectively controlled in approximately 40% of patients, necessitating the development of novel therapeutic agents. Activation of the A1 receptor (A1R) by endogenous adenosine is an intrinsic mechanism to self-terminate seizures and protect neurons from excitotoxicity. However, targeting A1R for neurological disorders has been hindered by side effects associated with its broad expression outside the nervous system. Here we aim to target the neural-specific A1R/neurabin/regulator of G protein signaling 4 (A1R/neurabin/RGS4) complex that dictates A1R signaling strength and response outcome in the brain. We developed a peptide that blocks the A1R-neurabin interaction to enhance A1R activity. Intracerebroventricular or i.n. administration of this peptide shows marked protection against kainate-induced seizures and neuronal death. Furthermore, in an AD mouse model with spontaneous seizures, nasal delivery of this blocking peptide reduces epileptic spike frequency. Significantly, the anticonvulsant and neuroprotective effects of this peptide are achieved through enhanced A1R function in response to endogenous adenosine in the brain, thus, avoiding side effects associated with A1R activation in peripheral tissues and organs. Our study informs potentially new anti-seizure therapy applicable to epilepsy and other neurological illness with comorbid seizures.

The next step of neurogenesis in the context of Alzheimer's disease

Among different pathological mechanisms, neuronal loss and neurogenesis impairment in the hippocampus play important roles in cognitive decline in Alzheimer's disease (AD). AD is a progressive and complex neurodegenerative diseases, which is very debilitating. The purpose of this paper is to review recent research into neurogenesis and AD and discuss how pharmacological drugs and herbal active components have impacts on neurogenesis and consequently improve cognitive functions. To date, despite huge research, no effective treatment has been approved for AD. Therefore, an avenue for future research and drug discovery is stimulating adult hippocampal neurogenesis (AHN). Evidence suggests that neurogenesis is regulated by the pharmacological treatment that may be recommended as a part of prophylaxis and therapeutic options for AD. However, the underlying mechanisms of regulating neurogenesis in AD are not well understood. To this point, we highlight to achieve an efficient treatment in AD by manipulating neurogenesis, it's necessary to target all steps of neurogenesis.

Treatment of epilepsy for people with Alzheimer's disease

BACKGROUND

Any type of seizure can be observed in Alzheimer's disease. Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with Alzheimer's disease. There are pharmacological and non-pharmacological treatments for epilepsy in people with Alzheimer's disease, however there are no current systematic reviews to evaluate the efficacy and tolerability of these treatments. This review aims to investigate these different modalities. This is an updated version of the Cochrane Review previously published in 2018.

OBJECTIVES

To assess the efficacy and tolerability of pharmacological or non-pharmacological interventions for the treatment of epilepsy in people with Alzheimer's disease (including sporadic Alzheimer's disease and dominantly inherited Alzheimer's disease).

SEARCH METHODS

For the latest update, on 3 August 2020 we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 31 July 2020). CRS Web includes randomized or quasi-randomized controlled trials from PubMed, EMBASE, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), and the Specialized Registers of Cochrane Review Groups, including Cochrane Epilepsy. In an effort to identify further published, unpublished and ongoing trials, we searched ongoing trials registers, reference lists and relevant conference proceedings; we also contacted trial authors and pharmaceutical companies.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials investigating treatment for epilepsy in people with Alzheimer's disease, with the primary outcomes of proportion of participants with seizure freedom and proportion of participants experiencing adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted data, cross-checked the data for accuracy and assessed the methodological quality. We performed no meta-analyses due to there being limited available data.

MAIN RESULTS

We included one randomized controlled trial (RCT) on pharmacological interventions; the trial included 95 participants. No studies were found for non-pharmacological interventions. Concerning the proportion of participants with seizure freedom, no significant differences were found for the comparisons of levetiracetam versus lamotrigine (RR) 1.20, 95% CI 0.53 to 2.71; 67 participants; very low-certainty evidence), levetiracetam versus phenobarbital (RR 1.01, 95% CI 0.47 to 2.19; 66 participants; very low-certainty evidence), or lamotrigine versus phenobarbital (RR 0.84, 95% CI 0.35 to 2.02; 57 participants; very low-certainty evidence). It seemed that levetiracetam could improve cognition and lamotrigine could relieve depression, while phenobarbital and lamotrigine could worsen cognition, and levetiracetam and phenobarbital could worsen mood. The risk of bias relating to allocation, blinding and selective reporting was unclear. We judged the certainty of the evidence for all outcomes to be very low.

AUTHORS' CONCLUSIONS

This review does not provide sufficient evidence to support levetiracetam, phenobarbital or lamotrigine for the treatment of epilepsy in people with Alzheimer's disease. Regarding efficacy and tolerability, no significant differences were found between levetiracetam, phenobarbital and lamotrigine. Large RCTs with a double-blind, parallel-group design are required to determine the efficacy and tolerability of treatment for epilepsy in people with Alzheimer's disease.

Treatment of epilepsy for people with Alzheimer's disease

BACKGROUND

Any type of seizure can be observed in Alzheimer's disease (AD). Antiepileptic drugs seem to prevent the recurrence of epileptic seizures in most people with AD. There are pharmacological and non-pharmacological treatments for epilepsy in people with AD. There are no current systematic reviews to evaluate the efficacy and tolerability of these treatments; this review aims to review those different modalities. This is an updated version of the original Cochrane Review published in Issue 11, 2016.

OBJECTIVES

To assess the efficacy and tolerability of pharmacological or non-pharmacological interventions for the treatment of epilepsy in people with AD (including sporadic AD and dominantly inherited AD).

SEARCH METHODS

For the latest update, on 10 July 2018 we searched the Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group's Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid 1946- ), ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform (ICTRP). In an effort to identify further published, unpublished and ongoing trials, we searched ongoing trials registers, reference lists and relevant conference proceedings, and contacted authors and pharmaceutical companies.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials investigating treatment for epilepsy in people with AD, with the outcomes of proportion of participants with seizure freedom or proportion of participants experiencing adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the titles and abstracts of identified records, selected studies for inclusion, extracted data, cross-checked the data for accuracy and assessed the methodological quality. We performed no meta-analyses due to the limited available data.

MAIN RESULTS

We included one randomized controlled trial on pharmacological interventions with 95 participants. No studies were found for non-pharmacological interventions. Concerning the proportion of participants with seizure freedom, no significant differences were found for the comparisons of levetiracetam (LEV) versus lamotrigine (LTG) (risk ratio (RR) 1.20, 95% confidence interval (CI) 0.53 to 2.71), LEV versus phenobarbital (PB) (RR 1.01, 95% CI 0.47 to 2.19), or LTG versus PB (RR 0.84, 95% CI 0.35 to 2.02). It seemed that LEV could improve cognition and LTG could relieve depression, while PB and LTG could worsen cognition, and LEV and PB could worsen mood. Unclear risk of bias was found in allocation, blinding and selective reporting. We judged the quality of the evidence to be very low.

AUTHORS' CONCLUSIONS

This review does not provide sufficient evidence to support LEV, PB or LTG for the treatment of epilepsy in people with AD. Regarding efficacy and tolerability, no significant differences were found between LEV, PB and LTG. Large randomized controlled trials with a double-blind, parallel-group design are required to determine the efficacy and tolerability of treatment for epilepsy in people with AD.

New-onset epilepsy in the elderly

People who are 60 years old and older have the highest incidence of developing new-onset epilepsy. The increase of the ageing population has resulted in a greater number of patients with new-onset epilepsy or at risk of developing the condition. Previously published review articles regarding epilepsy in older patients have had a broad focus, including people who were diagnosed with epilepsy in their childhood or middle age. The present review focuses on the causes, treatment, prognosis and psychosocial impact of new-onset epilepsy in people aged ≥60 years. Following a search of the medical electronic databases and relevant references, we identified 22 studies overall that met the inclusion criteria. Only four randomized clinical trials (RCTs) were identified that compared different antiepileptic drug treatments in this population, demonstrating that newer-generation antiepileptic drugs (e.g. lamotrigine and levetiracetam) were generally better tolerated. One uncontrolled study provided promising evidence of good outcomes and safety for surgical resection as a treatment for people with uncontrolled seizures. Five studies reported that people ≥60 years with new-onset epilepsy have significant cognitive impairments (e.g. memory loss) and psychological issues including depression, anxiety and fatigue. We found that there is limited evidence to guide treatment in people with Alzheimer's disease and epilepsy. The specific features of new-onset epilepsy in this target population significantly influences the choice of treatment. Cognitive and psychiatric screening before treatment may be useful for management. Two studies with proposed guidelines were identified but no formal clinical practice guidelines exist for this special population to assist with appropriate management. There is a need for more RCTs that investigate effective treatments with limited side effects. More research studies on the psychosocial effects of new-onset epilepsy, and long-term outcomes, for people aged ≥60 years are also required.

Tau-Induced Pathology in Epilepsy and Dementia: Notions from Patients and Animal Models

Patients with dementia present epilepsy more frequently than the general population. Seizures are more common in patients with Alzheimer’s disease (AD), dementia with Lewy bodies (LBD), frontotemporal dementia (FTD) and progressive supranuclear palsy (PSP) than in other dementias. Missense mutations in the microtubule associated protein tau (MAPT) gene have been found to cause familial FTD and PSP, while the P301S mutation in MAPT has been associated with early-onset fast progressive dementia and the presence of seizures. Brains of patients with AD, LBD, FTD and PSP show hyperphosphorylated tau aggregates, amyloid-β plaques and neuropil threads. Increasing evidence suggests the existence of overlapping mechanisms related to the generation of network hyperexcitability and cognitive decline. Neuronal overexpression of tau with various mutations found in FTD with parkinsonism-linked to chromosome 17 (FTDP-17) in mice produces epileptic activity. On the other hand, the use of certain antiepileptic drugs in animal models with AD prevents cognitive impairment. Further efforts should be made to search for plausible common targets for both conditions. Moreover, attempts should also be made to evaluate the use of drugs targeting tau and amyloid-β as suitable pharmacological interventions in epileptic disorders. The diagnosis of dementia and epilepsy in early stages of those diseases may be helpful for the initiation of treatments that could prevent the generation of epileptic activity and cognitive deterioration.