A Review of Accelerated Long-Term Forgetting in Epilepsy

Abstract

Accelerated long-term forgetting (ALF) is a memory disorder that manifests by a distinct pattern of normal memory for up to an hour after learning, but an increased rate of forgetting during the subsequent hours and days. The topic of ALF has gained much attention in group studies with epilepsy patients and the phenomenon has been shown to have contradictory associations with seizures, epileptiform activity, imaging data, sleep, and antiepileptic medication. The aim of this review was to explore how clinical and imaging data could help determine the topographic and physiological substrate of ALF, and what is the possible use of this information in the clinical setting. We have reviewed 51 group studies in English to provide a synthesis of the existing findings concerning ALF in epilepsy. Analysis of recently reported data among patients with temporal lobe epilepsy, transient epileptic amnesia, and generalized and extratemporal epilepsies provided further indication that ALF is likely a disorder of late memory consolidation. The spatial substrate of ALF might be located along the parts of the hippocampal–neocortical network and novel studies reveal the increasingly possible importance of damage in extrahippocampal sites. Further research is needed to explore the mechanisms of cellular impairment in ALF and to develop effective methods of care for patients with the disorder.

Systematic Review of Accelerated Long-term Forgetting in Children and Adolescents With Neuropediatric Diseases

“…Despite the increasing number of studies on ALF, its underlying mechanism is still unclear, and findings remain debated. 15 Findings of impaired memory function at late delays are explained by problems of memory consolidation, and it is assumed that ALF is caused by structural lesions or functional impairments or both. 15,16 However, there are also results supporting the hypothesis that ALF is rather a problem of memory retrieval 8 and may, therefore, be linked to executive functioning.…”

“…Therefore, the aim of this systematic review was to assess published data on ALF in children and adolescents with neurologic diseases. Based on previous findings in adults, 6-8,10-13,15 we hypothesized (1) that ALF in children and adolescents is not epilepsy specific and (2) that ALF is not only a phenomenon of verbal memory. 15 Furthermore, we were interested in whether delayed memory performance in children is associated with epilepsy variables, sleep, or executive functioning.…”

“…The core literature on ALF so far has focused on adults, and several reviews on this topic have been published. 1,5,15 However, studies on pediatric ALF are still scarce, and to our knowledge, no review of ALF in children and adolescents has yet been performed. In light of the particular vulnerability to neurologic conditions of the developing brain, the evaluation of ALF in the pediatric age group is of utmost importance.…”

“…15 Furthermore, we were interested in whether delayed memory performance in children is associated with epilepsy variables, sleep, or executive functioning. 15…”

The Role of the Negative Regulation of Microglia-Mediated Neuroinflammation in Improving Emotional Behavior After Epileptic Seizures

“…Epilepsy affects more than 70 million people worldwide ( 3 ), 60% of which experience childhood onset ( 4 ). In children with epilepsy, 10–30% have temporal lobe epilepsy (TLE) involving the hippocampus, amygdala, entorhinal cortex and other limbic system structures, some of which easily develop refractory epilepsy or persistent epilepsy, resulting in varying degrees of learning and memory impairment ( 5 ), cognitive dysfunction ( 6 ), and mood disorders ( 7 , 8 ). However, reducing brain injury and emotional and behavioral disorders that develop after the onset of epilepsy has become a problem requiring close attention and considerable effort from pediatricians to find a solution ( 9 ).…”