Articles

Postconcussional Disorder: Common result of head injury

Part 2: Features of Postconcussional Disorder
Features
The signs and symptoms of PCD may be physical, cognitive or emotional. PCD has been included in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).7

Table 2: Definition of Mild Traumatic Brain Injury

A patient with mild traumatic brain injury has had traumatically induced physiologic disruption of brain function, manifested by at least one of the following:

1. Any period of loss of consciousness.
2. Any loss of memory immediately before or after the accident.
3. Any alteration in the mental state at the time of the accident. (e.g. feeling disoriented, dazed or confused)
4. Focal neurological deficits that may be transient.

The severity of the injury does not exceed the following:
a) Loss of consciousness of approximately 30 minutes or less.
b) An initial Glasgow Coma Scale of 13 to 15 points after 30 minutes.
c) Post-traumatic amnesia not greater than 24 hours.

PCD is listed in the DSM-IV in a section that lists diagnoses which require further study. The essential feature, according to DSM-IV, is an acquired impairment in cognitive functioning, accompanied by specific neurobehavioural symptoms. The impairment occurs as a consequence of closed-head injury of sufficient severity to have produced a significant cerebral concussion.

Manifestations of PCD include loss of consciousness, post-traumatic amnesia and , less commonly, post-traumatic onset of seizures. There also must be documented cognitive deficits in either attention (e.g., concentration, shifting focus of attention, performing simultaneous cognitive tasks) or memory (e.g., learning of recalling information). Other symptoms that may occur include:

Becoming fatigued easily.
Disordered sleep.
Headache.
Vertigo or dizziness.
Irritability or aggression with little or no provocation.
Anxiety.
Depression or affective ability.
Apathy or lack of spontaneity.
Other changes of personality (e.g., social or sexual inappropriateness).

The cognitive disturbances and somatic and behavioural symptoms develop after the head trauma has occurred, or represent a significant increase in pre-existing symptoms. The cognitive and neurobehavioural sequelae are accompanied by significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning.

Contrary to the DSM-IV definition, there are many reported cases of patients with long-term PCD symptoms who did not lose consciousness at the time of injury.8 Following MTBI, patients may have an impairment in their level of consciousness, but they may not have completely lost consciousness. Patients may also be able to move, talk and respond in a reasonable fashion and yet lack any insight into their actions or retain any memory of events around the time of injury.

Post-traumatic amnesia (PTA), an indicator of concussion which may lead to PCD, also needs to be adequately defined. The period of PTA is the interval between injury and the time when the patient begins to establish continuous memory of ongoing events. PTA includes the time during which the patient was awake but confused. Patients need to be carefully questioned.

Key Point

The cognitive and neurobehavioural sequelea are accompanied by significant impairment in social and occupational functioning and represent a significant decline from a previous level of functioning.

Approximately one-third of patients with traumatic brain injury give a history of an island of recall well before memories become continuous, resulting in a potential error in underestimating the total duration of PTA.9 The duration of PTA provides one of the best yardsticks of organic brain injury, correlating with the severity of diffuse brain damage and the overall degree of disability.10 Researchers have correlated the duration of PTA with the duration of time off work, the extent of neurologic disorder and associated physical disability, memory impairment and social and psychiatric disability.11

A more complete description of the physical symptoms, cognitive deficits and emotional sequelae of PCD follows.

Physical symptoms

Headache pain is the most predominant physical symptom of PCD.
Headache pain resulting from PCD may be extremely distressing and disabling.
Vomiting, nausea, drowsiness and blurred vision are usually short-lived complaints. They are early symptoms which are experienced shortly following the head injury and are the typical complaints on the following morning. Headache pain and dizziness, however, may persist over time.
Tinnitus may be disabling for some patients and may affect sleep.
Diminished sense of smell may also be dangerous for patients if they are unable to smell smoke.

Cognitive deficits
The cognitive deficits of PCD are particularly disturbing for patients. A report from a neurosurgeon who experienced PCD following a minor sporting injury documents the handicap imposed by the subtle impairment of intellectual functioning.12 The neurosurgeon had difficulty remembering recent events, locating objects necessary for work, experienced problems with memory and the ability to concentrate on tasks. These symptoms persisted, but gradually improved over a period of 18 months. Family members frequently provide a history of the patient having memory difficulties, which may include:

Difficulty organizing or processing information.
Specific short-term memory deficits (e.g., verbal versus nonverbal).
Trouble sustaining attention and easy fatiguability.
Impaired selective attention and diminished ability to scan and shift information back and forth. Consequently, the patient frequently "gets lost" in group communication.
Difficulties with initiation and planning of goal-directed activities.
Impairment of abstract reasoning (e.g., the patient may interpret information literally and not symbolically, missing the true meaning).
There may also be difficulty inhibiting action before action is required of after it should stop, resulting in impulsive and perseveration behavioural problems.
Difficulty ordering or sequencing information.
Difficulty learning from experience.
Difficulty knowing when, where and how to ask for help.

Disorder of judgment and perception may cause misinterpretation of actions of intention of others. There may also be a tendency towards socially inappropriate verbal communication. Patients may also have an unrealistic appraisal of themselves and their strengths and weaknesses after brain injury. They often do not fully understand the nature of their deficits. Speed of information processing may also be slowed extremely, affecting reaction time and psychomotor activities (e.g., talking, writing, performing mechanical tasks). Patients may also be confused when presented with multiple bits of information at one time.

Key Point

Vomiting, nausea, drowsiness and blurred vision are usually short-lived complaints. They are early symptoms which are experienced shortly following the head injury and are the typical complaints on the following morning. Headache pain and dizziness, however, may persist over time.

There may be communication disorders including overtalkativeness, disorder of thought and speech and inefficient word retrieval. Patients may use peculiar words and phrases and, in some cases patients may experience anomia or an uninhibited choice of words (e.g., four-letter superlatives). Patients are also extremely sensitive to the effects of lack of sleep, fatigue, stress, drugs and alcohol and their cognitive abilities will decline if these stressors occur.

Emotional sequelae
Numerous emotional sequelae occur with PCD. Common personality changes following brain injury include:

Irritability.
Impulsivity.
Acting in socially inappropriate ways.
Being unaware of one's personal impact on others.
Being more emotional.

Emotional problems typically include poor tolerance for frustration, greater dependence on others, insensitivity to others and generally a more demanding attitude and increased helplessness. Emotional sequelae is understandable, given the areas of the brain which are most susceptible to damage following mild head injury. The frontal lobes are responsible for executive functioning, which includes the expression of language and speech, empathy with others, the ability to put aside immediate gratification, planning complex activities and the ability to anticipate the consequences of action. Damage to the frontal lobes may, therefore, cause a lack of foresight and insight as well as diminished control over impulsive and instinctive behaviour. In addition to emotional sequelae due to brain damage itself, secondary depression and anxiety may occur. Some patients may already be suffering from mild anxiety or depression that becomes exacerbated.13 Premorbid personality traits may also become exaggerated following MTBI. For example, a patient with premorbid perfectionist traits may develop an obsessive-compulsive disorder.

Read Part 3 »