Postictal state

Jerome Engel defines the postictal state as "manifestations of seizure-induced reversible alterations in neuronal function but not structure." Commonly after a seizure, a person feels mentally and physically exhausted for up to one or two days. The most common complaint is an inability to think clearly, specifically "poor attention and concentration, poor short term memory, decreased verbal and interactive skills, and a variety of cognitive defects specific to individuals." Postictal migraine headaches are a major complaint among persons with epilepsy, and can have a variety of etiologies. One possible cause of these migraines is high intracranial pressure resulting from postictal cerebral edema. At times, a person may be unaware of having had a seizure, and the characteristic migraine is their only clue. Postictal bliss or euphoria is also reported following seizures. This has been described as a highly blissful feeling associated with the emergence from amnesia. Feelings of depression before a seizure may lead to postictal euphoria. Some of postictal symptoms are almost always present for a period of a few hours up to a day or two. Absence seizures do not produce a postictal state and some seizure types may have very brief postictal states. Otherwise, the lack of typical postictal symptoms, such as confusion and lethargy following convulsive seizures, may be a sign of non-epileptic seizures. Usually such seizures are instead related to syncope or have a psychogenic origin ("pseudoseizures"). The postictal state can also be useful for determining the focus of the seizure. Decreased verbal memory (short term) tends to result from a seizure in the dominant hemisphere, whereas seizures in the non-dominant hemisphere tend to manifest with decreased visual memory. Inability to read suggests seizure foci in the language areas of the left hemisphere, and "after a seizure semivoluntary events as mundane as nose wiping tend to be done with the hand ipsilateral to (that is on the same side as) the seizure focus." ==Mechanism==

While it might seem that the neurons become “exhausted” after the near-constant firing involved in a seizure, the ability of the neuron to carry an action potential following a seizure is not decreased. Neurons of the brain fire normally when stimulated, even after long periods of status epilepticus. Hammers notes that cerebral bloodflow after a seizure cannot account for the increase in PET activity observed. Regional bloodflow can increase by as much as 70–80% after seizures but normalizes after 30 minutes. The shortest postictal interval in their study was 90 minutes and none of the patients had seizures during the scanning. It has been predicted that a decrease in opioid activity following a seizure could cause withdrawal symptoms, contributing to postictal depression. The opioid receptor connection with mitigating seizures has been disputed, and opioids have been found to have different functions in different regions of the brain, having both proconvulsive and anticonvulsive effects. Animal models are difficult for this type of study because each type of seizure model produces a unique pattern of perfusion and metabolism. Thus, in different models of epilepsy, researchers have had differing results as to whether or not metabolism and perfusion become uncoupled. Hosokawa's model used EL mice, in which seizures begin in the hippocampus and present similarly to the behaviors observed in human epileptic patients. If humans show similar uncoupling of perfusion and metabolism, this would result in hypoperfusion in the affected area, a possible explanation for the confusion and 'fog' patients experience following a seizure. == See also ==