Background
Consistent with the biopsychosocial model of understanding human emotions and behavior, agitation, aggression, and violence are most often the result of a complex matrix of neurobiology (including genetics and neuropathology), life experience (including the unconscious sequelae of neglect and/or abuse), and the social context, in which these feelings and behaviors occur. When such signs and symptoms occur in people with brain disorders, they constitute a major source of disability to individuals so affected, as well as being a significant source of stress to their families.
Agitation and aggression may emerge during the acute stages of recovery from brain injury, where such behaviors can endanger the safety of the patients and their caregivers. Agitation that occurs in the hospital after traumatic brain injury (TBI) may also be predictive of longer lengths of stay and decreased cognition, with low frustration tolerance and explosive behavior being elicited by minimal provocation. These episodes may range in severity from mild irritability to outbursts that result in significant damage to property and physical trauma to others. Not infrequently, people who suffer aggressive outbursts, because of central nervous system (CNS) lesions must be relegated for prolonged periods of time to highly restrictive environments—such as state psychiatric facilities—for the protection of themselves and of others.
Prevalence
Overview
The prevalence of agitation and aggression related to neurologic disorders varies widely based on the specific condition and study. This variability depends on the nature of the population being studied (e.g., in acute general hospital settings vs. rehabilitation and outpatient settings), the age and gender of the sample, whether there was a high prevalence of preexisting personality disorders in the sample, and so on. For example, aggressive behavior during a seizure is infrequent and, when it occurs is most random and not directed. During the immediate postictal phase, agitation and aggression occur when the patient is confused, suffers delirium, and often is directed toward caregivers.
Alzheimer disease, the most common type of dementia, often causes behavioral changes along with memory loss. Several studies, surveying individuals in homes and chronic care residences, have indicated that agitation was the most common and the most persistent symptom; agitation and physical aggression were both likely to increase in prevalence over time. Studies of the emotional and psychiatric syndromes associated with epilepsy have documented an increase in hostility, irritability, and aggression interictally. In individuals with temporal lobe epilepsy, aggressive behavior was associated with early onset of seizures, a long duration of behavioral problems, and male gender. Those patients who have mental retardation and require institutionalization frequently exhibit aggressive behaviors. Forty percent of residents in institutions for mentally retarded individuals, have disruptive behaviors or injure themselves or others, or damage property.
Mood lability, irritability, agitation, and aggression are common and often highly disabling after TBI, and this common condition offers an excellent paradigm and prototype for the prevalence, neurobiology, pathophysiology, and treatment of these symptoms and behaviors across the entire neuropsychiatric spectrum of disorders. Therefore, in the remainder of this chapter, the authors will focus largely upon agitation and aggression following TBI wherein the facts and principles presented can be generalized to other neuropsychiatric illnesses.
Prevalence of Agitation and Aggression in Patients with TBI
During the acute recovery period, 11% to 96% of individuals with brain injury exhibit agitated behavior.1 After the acute recovery phase, irritability or bad temper is common. Studies of mild TBI have evaluated individuals for much briefer periods of time: 1-year estimates from these studies range from 5% to 70%. Prediction of who will develop aggressive behavior after brain injury is challenging. Risk factors may include the presence of major depression, frontal lobe lesions, poor preinjury social functioning, irritability, impulsivity, and a preinjury history of aggression, and a history of alcohol and substance abuse; neuropsychological test performance does not consistently predict propensity toward violence in those who have suffered brain injury.
Characteristics of Aggression after Brain Injury
In the acute phase after brain injury, patients often experience a period of agitation and confusion, which may last from days to months. In rehabilitation facilities, these patients are described as “Confused, Agitated” (a Rancho Los Amigos Scale score of 4), and have characteristics similar to those with delirium. Agitation usually appears in the first 2 weeks of hospitalization and resolves within 2 weeks. Restlessness may appear after 2 months and may persist for 4 to 6 weeks. In our clinical experience, after the acute recovery phase has resolved, continuing aggressive outbursts have typical characteristics (see Table 16.1). These episodes may occur in the presence of other emotional changes or neurologic disorders that occur secondary to brain injury, such as mood lability or seizures.
Neuroanatomy of Aggression
Many areas of the brain are involved in the production and mediation of aggressive behavior, and lesions at different levels of neuronal organization can elicit specific types of aggressive behavior, but especially those in the frontotemporal region. Certain behavioral syndromes have been related to damage to specific areas of the frontal lobe. The orbitofrontal syndrome is associated with behavioral excesses (e.g., impulsivity, disinhibition, hyperactivity, distractibility, and mood lability). Outbursts of rage and violent behavior occur after damage to the inferior orbital surface of the frontal lobe and anterior temporal lobes. The current diagnostic category in Diagnostic and Statistical Manual of Mental Disorders, 4th edition text revision (DSM-IV-TR) is “personality change due to a general medical condition”.2 Patients with aggressive behavior would be specified as “aggressive type,” whereas those with mood lability would be specified as “labile type.”
Neurotransmitters in Aggression
Many neurotransmitters are involved in the mediation of aggression. Among the neurotransmitter systems, serotonin, norepinephrine, dopamine, acetylcholine,
and the γ-aminobutyric acid (GABA) systems have prominent roles in influencing aggressive behavior. It is often difficult to translate studies of aggression in various species of animals to a complex human behavior. Multiple neurotransmitter systems may be altered simultaneously by an injury that affects diffuse areas of the brain, and it may not be possible to relate change in any one neurotransmitter to a specific behavior, such as aggression. In addition, different transmitters affect one another, and frequently the critical factor is the relationship among the neurotransmitters. There is the most data focusing on the serotonergic and noradrenergic systems in mediating aggressive behavior.
and the γ-aminobutyric acid (GABA) systems have prominent roles in influencing aggressive behavior. It is often difficult to translate studies of aggression in various species of animals to a complex human behavior. Multiple neurotransmitter systems may be altered simultaneously by an injury that affects diffuse areas of the brain, and it may not be possible to relate change in any one neurotransmitter to a specific behavior, such as aggression. In addition, different transmitters affect one another, and frequently the critical factor is the relationship among the neurotransmitters. There is the most data focusing on the serotonergic and noradrenergic systems in mediating aggressive behavior.
TABLE 16.1 Characteristic Features of Aggression after Brain Injury | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Assessment
Differential diagnosis
Individuals who exhibit aggressive behavior or agitation associated with neuropsychiatric disorders require a thorough assessment. Multiple factors may play a significant role in the production of aggressive behaviors in these patients.
For people who suffer from TBI or severe stroke that leads to coma, during the time period of emergence from coma, agitated behaviors can occur because of delirium. The usual clinical picture is one of restlessness, confusion, and disorientation.
For patients who become aggressive after stroke, TBI or other CNS insults, it is important to assess systematically the presence of concurrent neuropsychiatric disorders, because this may guide subsequent treatment. Therefore, the clinician must diagnose psychosis, depression, mania, mood lability, anxiety, seizure disorders, and other concurrent neurologic conditions.
When aggressive behavior or agitation occurs during later stages of recovery from an acute insult to the brain, after confusion and posttraumatic amnesia have resolved, the clinician must determine whether the aggressivity and impulsivity of the individual antedated, was caused by, or was aggravated by the brain injury. For example, patients who have suffered a TBI or stroke may have a history of neuropsychiatric problems including learning disabilities, attentional deficits, behavioral problems, or personality disorders.
Drug effects and side effects commonly result in disinhibition or irritability (see Table 16.2). The most common drug associated with aggression is alcohol, during both intoxication and withdrawal. Stimulating drugs, such as cocaine and amphetamines, as well as the stimulating antidepressants, may produce severe anxiety and agitation in patients with or without brain lesions. Many other drugs may produce confusional states, especially anticholinergic medications that cause agitated delirium.
Patients with TBI, stroke, and other neuropsychiatric conditions with acute onset are susceptible to developing other medical disorders that may increase aggressive behaviors (see Table 16.3). The clinician should not, a priori, assume that the brain injury, per se, is the cause of the aggressivity, but should assess the patient for the presence of other common etiologies of aggression. Because patients with neurologic disorders are
more susceptible to accidents, falls, and other sources of brain disorders, a neurologic disorder may be the “underlying condition” that leads to the traumatic injury. In addition, when there are exacerbations or recurrences of aggressive behavior in a patient who has been in good control, an investigation must be completed to search for other etiologies, such as medication effects, infections, pain, or changes in social circumstances.
Psychosocial factors are important in the expression of aggressive behavior in patients with neuropsychiatric disorders. For example, those who have suffered TBI may be acutely sensitive to changes in their environment or to variations in emotional support. Social conditions and support networks that existed before the injury affect the symptoms and course of recovery. Certain patients become aggressive only in specific circumstances, such as in the presence of particular family members. This relation suggests that there is some maintained level of control over aggressive behaviors, and that the level of control may be modified by behavioral therapeutic techniques. Most families require professional support to adjust to the impulsive behavior of a violent relative with organic dyscontrol of aggression. Frequently, efforts to avoid triggering a rageful or violent episode often lead families to withdraw from a patient. This can result in the paradox that a way that the patient learns to gain attention by being aggressive. Therefore, the unwanted behavior is unwittingly reinforced by familial withdrawal.
TABLE 16.2 Medications and Drugs Associated with Aggression | |
|---|---|
|
TABLE 16.3 Common Etiologies of Aggression in Individuals with TBI | |
|---|---|
|
Documentation of Aggressive Behavior
Before therapeutic intervention is initiated to treat violent behavior, the clinician should document the baseline frequency of these behaviors. There are spontaneous day-to-day and week-to-week fluctuations in aggression that cannot be validly interpreted without prospective documentation. Aggression—like certain mood disorders—may have cyclic exacerbations. It is essential that the clinician establishes a treatment plan, using objective documentation of aggressive episodes to monitor the efficacy of interventions and to designate specific time frames for the initiation and discontinuation of pharmacotherapy of acute episodes and for the initiation of pharmacotherapy for chronic aggressive break behavior.Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
