Effects of Epilepsy on Memory - Therapeutic Implications, Biomarkers, and Comorbidities

Epilepsy is well known to affect cognitive functions, depending on the site of the epileptic lesion, type and frequency of seizures, and the spread of epileptic activity over functional brain regions. A common complaint among patients with temporal lobe epilepsy are memory problems, often within the verbal domain, but not limited to it. In addition to the epileptic lesion and pathological activity, epilepsy-related sleep disturbance and antiepileptic drugs were shown to negatively affect memory. Additionally, age and age of seizures onset need to be considered, as epilepsy has also been shown to interact with neurodegenerative diseases such as Alzheimer’s dementia. Furthermore, depressive mood, as a consequence from the burden of epilepsy, hampers cognitive functions and especially memory. Poor performance in memory tests needs to be considered alongside attentional deficits, which might arise from the very same sources: lesions, pathological activity, sleep, medication, and mood.

Although reports on memory deficits in epilepsy are numerous, the interrelationship between memory subdomains and the mediating factors for the negative impact of epilepsy on memory is not clear, yet. This research topic encourages investigation of the interrelationship between epilepsy types, lesion, interictal epileptic activity, seizures, antiepileptic medication, sleep, and mood in terms of their impact on memory. Most importantly, we want to increase awareness that the assessment of epilepsy effects on memory and cognition shall not be limited to the verbal domain, as these effects depend clearly on the type of epilepsy and the spread of pathological lesions and epileptiform brain activity. As such, they can affect cognitive functions of memory and attention in general, or other very specific memory sub-domains, such as semantic vs. episodic memory, nondeclarative memory, procedural memory, and emotional responses.

Therapeutic implications with respect to medication and surgical interventions should be reviewed by providing a better understanding for the origin and nature of memory problems in the individual patient.

Thus, topic editors will welcome any types of manuscripts - research article, brief research article, review, and mini-review- about, but not limited to the following themes:

• Effects of epilepsy type, lesion, interictal epileptic activity, seizures, antiepileptic medication, sleep, and mood on memory in patients with epilepsy;

• Therapeutic implications in terms of medication and surgical intervention for memory in patients with epilepsy;

• The interaction between memory and attention in patients with epilepsy;

• Memory deficits in epilepsy in memory subdomains: declarative memory, i.e. semantic memory and episodic memory, as well as nondeclarative memory, i.e. procedural memory and emotional responses;

• The interrelationship between ageing, age of onset, and memory deficits in epilepsy;

• Biomarkers, e.g. in EEG and fMRI, that relate to memory deficits in epilepsy, helping to gain a better understanding of their underlying mechanisms.