Neuropsychiatric Sequelae of Moderate to Severe Head Injury Described in DSM-5
The DSM-5 addresses traumatic brain injury and its neuropsychiatric sequelae primarily through the Neurocognitive Disorders section, where TBI-related cognitive impairments are classified as either Mild or Major Neurocognitive Disorder due to Traumatic Brain Injury, based on the severity of posttraumatic cognitive impairments and their effects on everyday function rather than the initial injury severity. 1
DSM-5 Framework for TBI Sequelae
The DSM-5 provides a basic framework for the retrospective diagnosis of TBI and characterization of clinical presentation, representing a substantial improvement over DSM-IV-TR in evaluating persons with TBI. 1
Neurocognitive Disorder Classification
The DSM-5 distinguishes between Mild and Major Neurocognitive Disorder due to TBI based on the severity of posttraumatic cognitive impairments and their impact on everyday function, not on the initial severity of the brain injury itself. 1
The manual succinctly reviews the epidemiology, phenomenology, and natural history of TBI and highlights the need to consider differential diagnosis for persistent postconcussive symptoms. 1
Specific Neuropsychiatric Sequelae Recognized
Cognitive Impairments
Memory deficits and attention/information processing speed and efficiency are typically the cognitive domains most severely affected by head injury, with intellectual, language, and perceptual skills tending to be relatively preserved. 2
Cognitive impairment following moderate to severe closed head injury includes deficits in rate of information processing, attention, memory, cognitive flexibility, and problem solving. 3
Deficits in working memory, new learning, memory storage, memory retrieval, and organization of thoughts and behavior are characteristic cognitive sequelae. 4
Mood and Anxiety Disorders
Depressed mood, anxiety, and impulsive/aggressive behavior are among the most prevalent sequelae of severe TBI. 5
The anxiety/mood subtype is characterized by increased nervousness, feeling more emotional, hypervigilance, ruminative thoughts, feelings of being overwhelmed, depressed mood with sadness, anger, hostility/irritability, loss of energy, fatigue, and feelings of hopelessness. 4
Higher than expected rates of depressive syndromes and psychotic syndromes occur in the TBI population, with manic syndromes also associated with TBI. 3
Behavioral and Personality Changes
Prominent impulsivity, affective instability, and disinhibition are seen frequently secondary to injury to frontal, temporal, and limbic areas, characterizing the frequently noted "personality changes" in TBI patients. 3
These changes can exacerbate premorbid problems with impulse control, resulting in marked difficulties with substance use, sexual expression, and aggression. 3
Cognitive, mood, anxiety, thought, impulse, and substance disorders, along with a variety of personality disorders, can be seen following TBI. 6
Sleep Disturbances
Sleep disturbances, including difficulty initiating and/or maintaining quality sleep, excessive sleepiness, hypersomnia, or insomnia, are common in concussion and represent a concussion-associated condition. 4
Sleep disturbance is among the most prevalent sequelae of severe TBI. 5
Postconcussive Syndrome
The constellation of symptoms that make up the postconcussive syndrome are seen across the whole spectrum of brain injury severity and are likely to have an underlying neuropathologic, neurochemical, or neurophysiologic cause. 3
The DSM-5 text highlights the need to consider the differential diagnosis for persistent postconcussive symptoms. 1
Important Clinical Considerations
Diagnostic Challenges
The mixture of diffuse and focal injuries, combined with cognitive, language, somatic, and behavioral difficulties, do not fit easily into current diagnostic categories. 3
Assessment and treatment of neuropsychiatric sequelae is a complex and challenging process requiring consideration of multiple domains. 3
Psychotic Presentations
Psychosis following TBI, while relatively rare, usually presents with atypical features. 5
Delirium, while less common, can result from TBI and predisposes individuals to other psychiatric conditions. 5
Temporal Considerations
Following resolution of post-traumatic amnesia, deficits may be present in multiple cognitive domains, with memory and attention/information processing typically most severely affected. 2
The neuropsychiatric sequelae follow from typical injury profiles including orbitofrontal, anterior and inferior temporal contusions, and diffuse axonal injury affecting the corpus callosum, superior cerebellar peduncle, basal ganglia, and periventricular white matter. 3