Table 3.

An overview of posttraumatic encephalopathy, its stages, and their features

PTE Stage	Key Neurobehavioral Feature	Description
Posttraumatic Coma	Impaired arousal	A complete impairment of arousal (wakefulness) in which there is no response to sensory input and no spontaneous behavior (purposeful or non-purposeful).
Posttraumatic Delirium	Impaired attention	A state in which there is reduced clarity of awareness of the environment, as evidenced by a reduced ability to focus, sustain, or shift attention.
		Additional features may include: alterations of arousal, which may fluctuate over minutes, hours, or days; disturbances of sleep-wake cycle; motor restlessness; impairments of processing speed, working memory, episodic memory (including orientation), language/communication, and executive function; perceptual disturbances (i.e., illusions, hallucinations) emotional lability; verbally, physically, and/or sexually disinhibited behavior, agitation, and/or aggression.
Posttraumatic Amnesia	Impaired episodic memory	A state characterized by impaired new learning of declarative information, including orientation to time, place, and situation as well as autobiographical information for the peri- and immediate post- injury period; these impairments are not attributable to disturbances of wakefulness (coma) or awareness (delirium).
		In this state, selective and sustained attention are relatively normal; impairments of higher-level (alternating, divided) attention, working memory, and executive function (including insight) are present; emotional and behavioral disturbances may persist (i.e., emotional lability, irritability, depression, anxiety, psychosis, apathy, aggression); based on the patient’s cognitive status, these problems are not attributable to posttraumatic delirium, but instead represent the neuropsychiatric sequelae of focal injuries (i.e., orbitofrontal syndrome) or damage to neurobehaviorally salient networks.
Posttraumatic Dysexecutive Syndrome	Executive dysfunction, including executive control of ‘basic’ cognitive abilities	A state characterized by impaired intrinsic executive function (e.g., conceptualization, judgment, insight) and impaired executive control of other cognitive functions, including attention (i.e., alternating, divided), working memory, language (impaired word retrieval, not confrontation naming), motor planning, and declarative memory (impaired retrieval, not new learning).
		In this state, emotional and behavioral disturbances may persist (i.e., emotional lability, irritability, depression, anxiety, psychosis, apathy, aggression); based on the patient’s cognitive status, these problems are not attributable to posttraumatic delirium, but instead represent the neuropsychiatric sequelae of focal injuries (i.e., orbitofrontal syndrome) or damage to neurobehaviorally salient networks.