Epilepsy and Aggression

British psychiatrist Henry Maudsley wrote in 1873 that “whenever a murder has been committed suddenly, without premeditation, without malice, without motive, openly and in a way quite different from the way in which murders are commonly done, we ought to look carefully for evidence of previous epilepsy.” Thus, the relationship between epilepsy and violence has garnered considerable interest for more than a century.

There are at least five ways in which epilepsy might relate to aggression:

1.  Peri-ictal aggression, a term referring to aggression observed around the time of a seizure but in practice typically distinguished from postictal aggression and often used to refer to prodromal aggression seen in the hours or days prior to a seizure.

2.  Ictal aggression, referring to automatic and unconscious behaviors during an epileptic seizure.

3.  Postictal aggression, sometimes called postictal rage.

4.  The limbic psychotic trigger reaction, an entity posited to occur in a small proportion of persons with limbic foci in which a seizure equivalent causes a psychotic state that can lead to violence.

5.  Interictal aggression, referring to problematic irritability or violence occurring between seizures.

Most of the attention paid to aggression and epilepsy concerns complex partial seizures (CPS). Prior to the mid-1980s, this neurological disorder was often referred to as temporal lobe epilepsy. Since that time, recognizing that such seizures may have foci outside of the temporal lobes (most often on the frontal cortex or insula), the terminology of CPS has been used. It is important to state clearly that persons who have either lost consciousness or exhibit significantly altered consciousness very rarely commit directed violence during a seizure. In CPS, whether emanating from temporal or frontal lobe foci, typical behaviors are chewing, reaching, picking at clothing, pacing purposelessly, or flailing. When restrained, a person having a seizure may resist and harm the restrainer. Although somewhat complex aggressive, unequivocally ictal behaviors have occasionally been documented, such as a patient who tore a sink from a wall, another who repeatedly kicked a neighbor, or another with “wrestling seizures” who threw others to the ground during video/EEG-monitored seizure activity, the targets of the ictal aggression are virtually always targets of opportunity such as the nearest object or person. Ictal aggression, in the largest study, averaged 29 seconds and occurred in the earliest phase of a seizure. Planning and sequencing of complex motor actions involving multiple steps (such as seeking out a weapon and then a victim) are not consistent with ictal action.

Still, some patients experience prolonged episodes, perhaps lasting days, during which their seizures are so frequent that they never fully regain consciousness. This condition, called complex partial status epilepticus, is uncommon. During such episodes, the patient may seem to be awake and semiattentive to his or her environment and may perform more-complex actions than those seen during the actual ictus. At least two reports of confused aggressive behavior during EEG-confirmed partial complex status epilepticus have been published. It is within the realm of possibility, therefore, that a person experiencing status epilepticus could act out in violent ways, although such a patient would surely also exhibit some detectable disorientation.

Brain electrical activity is abnormal in patients with CPS for a period both before and after an ictus. An aura of fear is very common. The resulting hypervigilance and sense of impending danger may cause a patient to misinterpret environmental stimuli in a paranoid way and prepare for defensive aggression. Such prodromal aggression has been reported during the 72 hours prior to a seizure and has included irritable verbal or physical aggression toward selected targets. However, it is much more common for CPS patients to exhibit aggression in the postictal than in the preictal period. During a typical postictal period lasting from minutes to several hours, most patients are confused, withdrawn, or lethargic and often just nap. However, some patients recurrently become hostile, angry, and aggressive. Their actions may be much more complex than those observed during a seizure. Somewhat complex actions can perhaps appear to be planned and sequenced during this postictal confusional period, although, typically, a patient behaves in a simple, stereotypical way and has an incomplete memory for these events. Longer subacute postictal violence has also been described, shading into the descriptions of limbic psychotic trigger reaction or interictal aggression. One patient, for instance, about 6 to 24 hours after a flurry of seizures, exhibited a psychotic state with hyperreligiosity, paranoid delusions, and violence such as attempting to stab his sister with a knife and severely assaulting an uncle. This patient had no recall of the events and was remorseful when told of them.

The ictal psychotic trigger reaction has been proposed to account for episodes in which an otherwise nonviolent but perhaps socially isolated schizotypal person with a flat affect experiences episodes lasting approximately 20 minutes involving delusions, hallucinations, and attacks on victims of opportunity. Traumatic brain injury and abnormal EEGs (but not necessarily epileptiform discharges) are common. Transient abnormal amygdalar hyperactivation is hypothesized to account for such episodes.

The most common type of epilepsy-related aggression is interic-tal. The term technically refers to periods between seizures. However, given that depth electrode recordings have demonstrated that paroxysms of abnormal brain electrical activity often occur without any obvious clinical seizure, interictal is better understood as “between clinically obvious seizures.” Some patients may spend much of their lives attempting to function in society while paroxysmal depolarization shifts persistently disrupt frontolimbic brain function. Depth electrode studies also show that these abnormalities wax and wane. This may explain the observation that some patients with interictal aggression are chronically irritable and considered to have hostile personalities, whereas others exhibit sudden unexplained bursts of aggression that might be diagnosed as IED. The literature on interictal aggression is fraught with inconsistencies, with as few as 4.8 percent and as many as 50 percent of patient reported to exhibit rages.

It is important to be cautious about concluding that a person known to have epilepsy and interictal aggression is aggressive because of the epilepsy. Studies have shown that aggressive individuals with epilepsy tend to come from violent families and lower socioeconomic groups, have lower IQs, and have higher rates of perinatal and other trauma. Because any of these factors may elevate rates of aggression in persons without epilepsy, it can be hard to say when epilepsy is the major causal factor. One way to determine whether epilepsy or another factor is likely to account for aggression is to look at sibling controls: If a man is the only one of four brothers who has epilepsy and the only one who is violent, it is plausible to conclude that his neurological disorder rather than his developmental environment explains his aggression.

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  • Category: Nervous diseases