(Compiled from Victor Nell, Cross-Cultural Neuropsychological Assessment: Theory and Practice; Lawrence Erlbaum Associates, 2000)
Diffuse brain injuries are by far the most common – starting with those resulting from traffic accidents, blunt force trauma to the head and falls, and ending with anoxic, neurotoxic, infection-related (e.g. HIV), and caused by dementing illnesses.
1. Hypoarousal
Arises from damage to reticular activating system, also leads to hypofrontality due to relatively lower innervation of frontotemporal areas from ascending reticular activating system. Affects attention and concentration, especially in familiar situations. Appears as increased need for sleep, decreased ability to concentrate on daily tasks (reading, watching TV), reduced alcohol and noise tolerance.
2. Personality Changes
A. Anger and irritability, at worst – violent outbursts with partial amnesia, inability to control aggression.
B. Problems with speech pragmatics, including hyperverbality, sponginess (imprecise thought expression) and tangentiality.
C. Problems with social appropriateness, including appropriate social distance (being overly familiar or “too fast” in new relationships); nuances of social context (laughing at a funeral); self-presentation (dress, personal hygiene); understanding of what should be public or private; social perseveration (repeating the same behavior, e.g. joke, over and over, past the point where it is unwelcome); suspiciousness and touchiness.
D. Problems with affect and perception of emotions, including failures of empathy and sensitivity, emotional dullness leading to lack of motivation, and absence of fear leading to high-risk behaviors.
3. Cognitive Changes
A. Problems with memory, including secondary problems due to decreased attention and concentration (decreased encoding in familiar situations); secondary problems due to frontal executive deficit (forgetting to remember, organizational problems); primary problems due to limbic system/temporal sulcus damage (difficulties with new learning).
B. Problems with problem solving, including working memory; flexibility in set shifting and problem solving strategies (inability to try a different approach); faulty problem analysis and task overload (after solving part of a problem, giving up and starting over rather than persevering with a consistent strategy – often seen on Block Design).
C. Motivational deficits, including distractibility; failure to self-monitor and correct errors; a disjunction between saying and doing (e.g. big plans with no steps taken to achieve them).
4. Physical Impairment
Sensory and motor deficits.
