ABPN Brain Injury Medicine common mistakes
ABPN Brain Injury Medicine · Understand the traps and how to avoid them.
When a vignette shows a patient with severe TBI and a decreasing level of consciousness, choosing hyperventilation to a target PaCO2 of 25 mm Hg as the initial ICP-lowering maneuver rather than recognizing it as a temporizing bridge reserved for impending herniation.
Textbook and ATLS-style teaching emphasizes hyperventilation for acute herniation, so candidates over-apply it as routine first-line therapy and forget the cerebral ischemia risk from vasoconstriction.
What to do instead
Memorize the tiered ICP algorithm: sedation/analgesia, CSF drainage, osmotherapy (mannitol or hypertonic saline), then brief hyperventilation only for herniation, with normocapnia (PaCO2 ~35-40) as the default target.
Confusing the Glasgow Coma Scale eye, verbal, and motor subscores, particularly assigning an intubated patient a verbal score of 1 and then misclassifying total severity (e.g., calling GCS 3T 'mild' or failing to document the 'T').
Candidates memorize the total range but not the component anchors, and intubation forces a verbal score that changes the interpretation of the total.
What to do instead
Drill the component anchors (E4-1, V5-1, M6-1) and always report GCS as components plus total plus the 'T' modifier; know that GCS 13-15 is mild, 9-12 moderate, 3-8 severe.
On a question about post-traumatic amnesia duration and injury severity classification, using loss of consciousness duration alone and ignoring PTA, or mis-stating the PTA cutoffs.
LOC is the more familiar metric and candidates conflate the two; PTA thresholds are less frequently rehearsed.
What to do instead
Anchor the PTA cutoffs: <1 day mild, 1-7 days moderate, >7 days severe; and know LOC cutoffs (<30 min mild, 30 min-24 h moderate, >24 h severe) as a parallel axis.
Missing the diagnosis of second impact syndrome or, more commonly, failing to recognize autonomic dysfunction/paroxysmal sympathetic hyperactivity in a patient with post-TBI tachycardia, hypertension, diaphoresis, and posturing, instead attributing it to pain or sepsis alone.
The dysautonomic cluster mimics common ICU problems, and candidates do not have a structured trigger for 'sympathetic storm after TBI.'
What to do instead
Use the paroxysmal sympathetic hyperactivity framework: simultaneous tachycardia, hypertension, tachypnea, hyperthermia, diaphoresis, and dystonia after TBI, and exclude other causes; know it is distinct from seizure and from pain.
On cognitive-communication questions, labeling a patient's tangential, disinhibited, socially inappropriate speech as aphasia rather than recognizing executive dysfunction and frontal lobe injury.
Any language-related abnormality gets filed under 'aphasia,' and candidates do not systematically check fluency, comprehension, repetition, and naming to separate aphasia from executive/pragmatic deficits.
What to do instead
Apply the aphasia screen (fluency, comprehension, repetition, naming); if those are intact but discourse is disorganized or inappropriate, attribute it to executive/frontal dysfunction, not aphasia.
Recommending a return-to-play or return-to-activity timeline for concussion based only on symptom resolution, without applying stepwise graded exertion and the requirement of being symptom-free at each step.
Candidates default to a fixed number of days rather than the graduated protocol, and they forget that symptom resolution alone does not equal physiologic recovery.
What to do instead
Memorize the stepwise return-to-sport progression (symptom-limited activity through full contact, roughly 24 hours per step) and state that any symptom recurrence means dropping back a step.
Treating post-traumatic seizures and post-traumatic epilepsy as interchangeable, or failing to distinguish early (within 7 days) from late (>7 days) seizures when deciding on prophylaxis.
The two terms sound similar and candidates do not reliably anchor the 7-day boundary or the fact that prophylaxis does not prevent late epilepsy.
What to do instead
Anchor: early seizures occur within 7 days, late after 7 days; prophylaxis with phenytoin/levetiracetam reduces early seizures but does not prevent late post-traumatic epilepsy.
On questions about disorders of consciousness, using the terms coma, vegetative state/unresponsive wakefulness syndrome, and minimally conscious state interchangeably, or failing to identify that a patient with visual pursuit or reproducible command-following is minimally conscious.
The behavioral distinctions are subtle, and candidates rely on the overall 'unresponsive' appearance rather than on specific discriminating behaviors.
What to do instead
Memorize the discriminators: no wakefulness = coma; wakefulness without awareness = UWS/vegetative; reproducible but inconsistent awareness (pursuit, command-following, localization) = MCS; and know that MCS carries a better prognosis than UWS.
Ignoring decisional capacity and surrogate decision-making in a vignette about withdrawing care or enrolling a patient with cognitive impairment in research, and proceeding as if the patient's stated preference or family preference alone is sufficient.
Candidates focus on the clinical decision and skip the legal/ethical scaffolding; capacity assessment and surrogate hierarchy are dry, memorization-heavy topics.
What to do instead
For any high-stakes decision, explicitly assess the four capacity elements (understanding, appreciation, reasoning, expressing a choice); if absent, identify the legal surrogate and apply substituted judgment or best interests.
Attributing new cognitive or behavioral decline months after TBI to the original injury alone, without screening for treatable contributors such as sleep apnea, depression, hypothyroidism, medication effects, or normal pressure hydrocephalus.
Candidates anchor on the index injury and do not run a systematic differential for late decline, which is a common source of missed reversible causes.
What to do instead
Adopt a structured late-decline workup: sleep study, mood screen, thyroid and metabolic labs, medication review, and imaging for hydrocephalus or subdural collection before concluding the decline is fixed.