Mood Disorders: Protection of the Hyper-Excited Brain, or a Risk Factor?

Abstract

Emotional disturbances such as anxiety, fear, depression and aggression are often experienced by patients with temporal lobe epilepsy. These psychiatric symptoms may occur during or just after (postictal) a seizure; however, in some patients, they occur interictally ( i.e. between seizures) and may profoundly change the individual’s personality. Aside from confirming that a significant proportion of temporal lobe epileptics do suffer from interictal abnormal emotionality, there has been little progress to date in identifying the fundamental nature of these disturbances. There is a lack of evidences regarding the influence of activation of emotiogenic structures and emotional behavior on development of seizures. Kindling is a commonly used animal model for study of interictal emotionality and the effects of kindling and human epilepsy on emotional behavior are the primary focus of investigators and not vice versa. Respectively, the interrelation between emotional and seizure reactions was studied in Wistar albino rats. In our study we tried to elucidate: can emotional behavior evoked by stimulation of the emotiogenic zones of the hypothalamus or of induction of acute pain stress modify manifestations of generalized seizures within the period where a “full” epileptic syndrom has been stable formed earlier? Our leading hypothesis is as follow: the emotional disturbances can be considered as the emergence of instinctive behavior with an adaptive significance of defense and as a by-product of the inhibitory processes that build up to protect against the future occurrence of seizures.