Neurobiological evidence for epilepsy-induced interictal disturbances

Area of Science:

• Neuroscience
• Behavioral Neurology
• Epileptology

Background:

• The potential for seizures to cause enduring behavioral disturbances in individuals with epilepsy is often underestimated.
• Existing evidence suggests multiple hypotheses for how seizures and their treatment might lead to behavioral changes.
• Differentiating behavioral disturbances caused by the underlying neuropathology from those caused by seizures or medication is challenging.

Purpose of the Study:

• To emphasize the necessity of investigating the link between seizures and enduring behavioral disturbances.
• To explore potential mechanisms, including medication side effects, neuroendocrine dysfunction, sleep disturbances, and seizure activity itself.
• To highlight the value of clinical and animal studies in elucidating these complex relationships.

Main Methods:

• Review of existing clinical evidence and hypotheses regarding epilepsy and behavior.
• Consideration of mechanisms related to antiepileptic drugs, neuropathological processes, and seizure characteristics.
• Emphasis on experimental animal models to study secondary epileptogenesis and homeostatic mechanisms.

Main Results:

• Behavioral disturbances are more common with limbic system epilepsy, though lateralization effects remain debated.
• Some 'interictal' behaviors may be subtle ictal events, particularly with limbic seizures.
• Animal models demonstrate that seizures can trigger neuroendocrine changes and withdrawal symptoms, potentially causing depression.

Conclusions:

• It is crucial to acknowledge and investigate the possibility that seizures can induce lasting behavioral changes.
• Mechanisms involve indirect effects of medication, direct effects of seizures (including subtle ictal events), and underlying neuropathology.
• Further research, particularly using animal models, is essential to understand and potentially mitigate these behavioral consequences of epilepsy.