Military Acute Concussion Evaluation 2 (MACE 2) — Questions and Answers

Question 1: What is the 'blast overpressure' and how is it measured?

The pressure wave exceeding normal atmospheric pressure created by an explosion, measured in pounds per square inch (PSI) (Correct answer)
The temperature of the blast
The volume of the explosion sound
The speed of shrapnel

Correct answer: The pressure wave exceeding normal atmospheric pressure created by an explosion, measured in pounds per square inch (PSI)

Blast overpressure is the positive pressure phase of the blast wave. Even relatively low overpressure (5-15 PSI) can cause TBI. Higher pressures cause progressively more severe injuries to multiple organ systems.

Question 2: What is the neurometabolic cascade following concussion?

The physical impact of the skull hitting the brain
Bleeding inside the skull
A series of cellular and metabolic changes including ionic flux, energy crisis, axonal injury, and neuroinflammation that impair brain function (Correct answer)
Swelling of the brain stem

Correct answer: A series of cellular and metabolic changes including ionic flux, energy crisis, axonal injury, and neuroinflammation that impair brain function

After concussion, potassium floods out of cells while calcium rushes in, creating an energy crisis. Mitochondrial dysfunction, oxidative stress, and neuroinflammation follow, explaining symptoms even without visible structural damage.

Question 3: How does exertional testing factor into return-to-duty decisions?

Only desk-duty positions require exertion testing
Physical exertion is never tested
Exertional testing is optional
Service members must demonstrate they can perform physical exertion without symptom recurrence before returning to full duty (Correct answer)

Correct answer: Service members must demonstrate they can perform physical exertion without symptom recurrence before returning to full duty

Exertional testing is critical because concussion symptoms often recur with physical and cognitive stress. Service members must tolerate progressively increasing activity levels without symptom exacerbation before returning to duty.

Question 4: What is the military progressive return-to-activity protocol after concussion?

A stepwise program progressing from rest through light activity, moderate exercise, full exertion, and return to duty, with minimum 24 hours at each stage (Correct answer)
Rest for 30 days with no evaluation
Immediate return to full duty
A single fitness test before returning to duty

Correct answer: A stepwise program progressing from rest through light activity, moderate exercise, full exertion, and return to duty, with minimum 24 hours at each stage

The military uses a graduated return-to-activity protocol similar to civilian sport concussion guidelines: symptom-limited rest, light aerobic exercise, sport-specific exercise, full-contact practice equivalent, and return to duty.

Question 5: How can concussion symptoms be differentiated from combat stress reactions?

Through timing relative to injury, specific cognitive deficits on MACE, neurological findings, and the pattern of symptom onset and resolution (Correct answer)
Only brain imaging can distinguish them
They cannot be differentiated
Combat stress always involves loss of consciousness

Correct answer: Through timing relative to injury, specific cognitive deficits on MACE, neurological findings, and the pattern of symptom onset and resolution

Concussion symptoms are temporally linked to an injury event and include specific cognitive deficits. Combat stress reactions are related to psychological stressors and may not involve cognitive impairment on testing, though significant overlap exists.

Question 6: How soon after a suspected concussion should the MACE be administered?

Immediately (Correct answer)
Within 24 hours
After one week
After one month

Correct answer: Immediately

The MACE is designed for acute assessment, meaning it should be administered as soon as possible after a suspected concussion. Immediate evaluation is crucial for establishing baseline symptoms, identifying any red flag signs, and initiating appropriate medical management and removal from activity to prevent further injury.

Question 7: What should be done if a patient shows significant cognitive impairment during the MACE?

They should be sent for immediate advanced medical evaluation (Correct answer)
They should be given painkillers and monitored
They should rest and re-test after 24 hours
They should continue with normal activities

Correct answer: They should be sent for immediate advanced medical evaluation

Significant cognitive impairment identified during the MACE, especially if severe or worsening, indicates a potentially more serious brain injury or complication. In such cases, the protocol mandates immediate referral for advanced medical evaluation (e.g., neuroimaging, specialist consultation) to rule out conditions like intracranial bleeding.

Question 8: What symptom tracking tools are used to monitor concussion recovery?

Only verbal questioning
No standardized tools exist
Standardized symptom checklists (like the RPQ, NSI, or PCSS) that rate symptom severity on numeric scales over time (Correct answer)
Only brain imaging

Correct answer: Standardized symptom checklists (like the RPQ, NSI, or PCSS) that rate symptom severity on numeric scales over time

Validated symptom checklists (Neurobehavioral Symptom Inventory, Rivermead Post-Concussion Symptoms Questionnaire, Post-Concussion Symptom Scale) quantify symptom severity and track changes over time to guide clinical decisions.

Question 9: What research is being conducted on military blast-related TBI?

No research exists on blast TBI
Studies on blast physics, biomarkers, neuroimaging, blast exposure thresholds, protective equipment, and long-term outcomes of repeated blast exposure (Correct answer)
Only animal studies are conducted
Research was completed decades ago

Correct answer: Studies on blast physics, biomarkers, neuroimaging, blast exposure thresholds, protective equipment, and long-term outcomes of repeated blast exposure

Active research areas include blast wave modeling, blood-based biomarkers for rapid diagnosis, advanced neuroimaging (DTI, fMRI), blast exposure monitoring devices, improved helmet design, and longitudinal studies of blast-exposed veterans.

Question 10: Which of the following tests is typically included in the MACE neurological examination?

MRI scan
Lung capacity test
Blood glucose level
Verbal memory test (Correct answer)

Correct answer: Verbal memory test

The MACE neurological examination includes a cognitive screening component, and a verbal memory test is a standard part of this. This typically involves asking the individual to recall a list of words, which helps assess their immediate and delayed verbal memory, a key indicator of cognitive function post-concussion.

Question 11: What emotional and behavioral changes should be monitored after concussion?

Only anger is an emotional symptom
No emotional changes occur with concussion
Irritability, mood swings, anxiety, depression, decreased frustration tolerance, and personality changes (Correct answer)
Emotional changes only occur with severe TBI

Correct answer: Irritability, mood swings, anxiety, depression, decreased frustration tolerance, and personality changes

Concussion commonly affects emotional regulation through disruption of prefrontal cortex function and limbic system connections. Irritability, anxiety, depression, and reduced emotional control are common and often distressing symptoms.

Question 12: Which MACE score on the SAC is the cutoff considered positive for concussion?

Less than or equal to 20
Less than or equal to 25 (Correct answer)
Less than or equal to 28
Less than or equal to 23

Correct answer: Less than or equal to 25

A SAC score of 25 or below (≤25) is considered a positive screen for concussion on the MACE.

Question 13: What is the Warfighter Brain Health Initiative?

A veterans' employment program
A recruitment marketing campaign
A military fitness challenge
A DoD program focused on protecting service members' brain health through education, exposure monitoring, treatment advances, and policy development (Correct answer)

Correct answer: A DoD program focused on protecting service members' brain health through education, exposure monitoring, treatment advances, and policy development

The Warfighter Brain Health Initiative addresses the full spectrum of brain health: blast exposure monitoring, concussion prevention and treatment, mental health, sleep optimization, and long-term brain health for military personnel.

Question 14: During the MACE, which cognitive function is commonly tested?

Heart rate
Blood pressure
Memory recall (Correct answer)
Reflexes

Correct answer: Memory recall

Concussions frequently impair cognitive functions, particularly memory. The MACE includes specific tasks, such as word list recall, to assess both immediate and delayed memory. This helps identify any short-term memory deficits, which are a common sign of acute concussion.

Question 15: What is chronic traumatic encephalopathy (CTE)?

A condition caused by a single concussion
A curable form of brain injury
A progressive neurodegenerative disease associated with repeated head trauma, diagnosed definitively only at autopsy (Correct answer)
An acute condition occurring immediately after head trauma

Correct answer: A progressive neurodegenerative disease associated with repeated head trauma, diagnosed definitively only at autopsy

CTE is associated with repeated head impacts over years, causing tau protein accumulation in the brain. Symptoms include cognitive decline, behavioral changes, and depression. Currently, definitive diagnosis requires post-mortem brain examination.

Question 16: In the MACE, what is the significance of asking patients to recall a list of words?

To evaluate long-term memory
To measure problem-solving ability
To assess short-term memory and attention (Correct answer)
To test language skills

Correct answer: To assess short-term memory and attention

Asking patients to recall a list of words is a standard component of the MACE cognitive assessment. This task specifically evaluates immediate and short-term verbal memory, as well as the patient's ability to pay attention and encode new information, which are often impaired following a concussion.

Question 17: What is the Glasgow Coma Scale (GCS) and how does it classify TBI severity?

A pain rating scale from 1 to 10
A scoring system rating eye opening, verbal response, and motor response: Mild TBI (13-15), Moderate (9-12), Severe (3-8) (Correct answer)
A psychological assessment for PTSD
A physical fitness scoring system

Correct answer: A scoring system rating eye opening, verbal response, and motor response: Mild TBI (13-15), Moderate (9-12), Severe (3-8)

The GCS rates three components: Eye opening (1-4), Verbal response (1-5), and Motor response (1-6), totaling 3-15. Concussion (mild TBI) typically presents with GCS 13-15 with brief or no loss of consciousness.

Question 18: What is assessed during the neurological screening portion of the MACE?

Liver function
Respiratory rate
Muscle strength and coordination (Correct answer)
Blood oxygen levels

Correct answer: Muscle strength and coordination

The neurological screening portion of the MACE assesses various aspects of neurological function that can be affected by a concussion. This includes evaluating muscle strength, coordination, balance, and gait to identify any motor deficits or neurological impairments resulting from the head injury.

Question 19: How should pain management be approached in service members with concussion?

Only ice should be used, never medication
Immediately prescribe strong opioid medications
Use non-opioid approaches first (rest, ice, acetaminophen), avoid NSAIDs acutely due to bleeding risk, and avoid medications that may mask neurological changes (Correct answer)
Pain management is not necessary for concussion

Correct answer: Use non-opioid approaches first (rest, ice, acetaminophen), avoid NSAIDs acutely due to bleeding risk, and avoid medications that may mask neurological changes

Pain management after concussion prioritizes non-pharmacological approaches and non-opioid analgesics. NSAIDs may be avoided acutely (theoretical bleeding risk), and sedating medications that could mask neurological deterioration should be used cautiously.

Question 20: Which symptom might indicate the need for immediate medical attention during a MACE evaluation?

Slight nausea
Mild dizziness
Severe headache (Correct answer)
Mild fatigue

Correct answer: Severe headache

While mild symptoms are common with concussions, a severe headache, especially one that worsens, can be a "red flag" symptom indicating a more serious brain injury, such as an intracranial hemorrhage. The MACE protocol emphasizes identifying such severe symptoms that warrant immediate advanced medical evaluation.

Question 21: Which of the following is typically included in the cognitive testing section of the MACE?

Blood pressure measurement
Memory recall (Correct answer)
Reflex testing
Lung capacity test

Correct answer: Memory recall

Memory recall is a core component of the cognitive testing section in the MACE. This typically involves tasks like recalling a list of words immediately and after a delay, which helps assess both immediate and short-term memory function, frequently affected by concussion.

Question 22: What cognitive task is used in the Concentration section of the MACE?

Digits backwards (Correct answer)
Serial subtraction by 7s
Reciting the alphabet backwards
Listing the months of the year forward

Correct answer: Digits backwards

The Concentration section primarily uses digits backwards, where the examiner reads a sequence of numbers and the patient repeats them in reverse order.

Question 23: What is the normal recovery timeline for concussion?

24 hours
Recovery from concussion takes at least 1 year
Most service members recover within 7-14 days, though some may take several weeks; symptoms persisting beyond 3 months may indicate post-concussion syndrome (Correct answer)
Exactly 30 days for everyone

Correct answer: Most service members recover within 7-14 days, though some may take several weeks; symptoms persisting beyond 3 months may indicate post-concussion syndrome

The majority of concussions resolve within 1-2 weeks with proper management. However, approximately 10-20% of individuals experience prolonged symptoms. Recovery timelines vary based on injury severity, history, and individual factors.

Question 24: What cognitive function is tested by asking the patient to follow multi-step commands?

Executive function (Correct answer)
Visual processing
Respiratory function
Muscle coordination

Correct answer: Executive function

Multi-step commands require the patient to understand, remember, sequence, and execute several actions in a specific order. These abilities are core components of executive function, which encompasses planning, working memory, and problem-solving. Therefore, struggling with such tasks can indicate an impairment in these higher-level cognitive processes.

Question 25: Which of the following is NOT a typical component of the MACE cognitive testing?

Number sequencing
Orientation questions
Word recall
Blood glucose measurement (Correct answer)

Correct answer: Blood glucose measurement

The MACE cognitive testing focuses specifically on neurological and cognitive functions like orientation, memory recall, and number sequencing, which are directly impacted by concussion. Blood glucose measurement is a physiological test, not a cognitive one, and is not a typical component of the MACE's cognitive assessment.

Question 26: What are the four categories of concussion symptoms?

Only memory loss
Only dizziness and nausea
Only headache
Physical (headache, dizziness), cognitive (confusion, memory problems), emotional (irritability, anxiety), and sleep-related (insomnia, drowsiness) (Correct answer)

Correct answer: Physical (headache, dizziness), cognitive (confusion, memory problems), emotional (irritability, anxiety), and sleep-related (insomnia, drowsiness)

Concussion symptoms span four domains: physical (headache, nausea, balance problems, light/noise sensitivity), cognitive (confusion, slowed thinking, poor concentration), emotional (irritability, sadness, anxiety), and sleep (too much/too little).

Question 27: What is a primary blast injury mechanism?

Being thrown by the blast
Burns from the explosion
The direct effect of the blast overpressure wave on body tissues, particularly air-filled organs and the brain (Correct answer)
Injury from shrapnel

Correct answer: The direct effect of the blast overpressure wave on body tissues, particularly air-filled organs and the brain

Primary blast injuries result from the blast overpressure wave itself passing through the body, causing rapid compression and expansion of tissues. The brain is particularly vulnerable due to its semi-fluid nature within the rigid skull.

Question 28: When should a concussed service member be awakened during sleep for neurological checks?

Every 15 minutes for 72 hours
Never interrupt sleep after concussion
Every hour for the first night
Only when red flag symptoms were present at initial assessment or when the mechanism of injury suggests potential for more serious intracranial pathology (Correct answer)

Correct answer: Only when red flag symptoms were present at initial assessment or when the mechanism of injury suggests potential for more serious intracranial pathology

Current evidence suggests that sleep is beneficial for concussion recovery and unnecessary interruptions are counterproductive. Neurological checks during sleep are warranted only when there is concern for intracranial bleeding or more severe injury.

Question 29: What balance and vestibular symptoms are associated with concussion?

Only severe TBI causes dizziness
Concussion does not affect balance
Dizziness, vertigo, balance problems, motion sensitivity, and difficulty with rapid head movements (Correct answer)
Balance problems only occur in elderly patients

Correct answer: Dizziness, vertigo, balance problems, motion sensitivity, and difficulty with rapid head movements

The vestibular system is commonly disrupted by concussion, causing dizziness, balance impairment, and motion sensitivity. These symptoms are assessed through balance testing (BESS) and may require vestibular rehabilitation.

Question 30: What aspect of neurological function is assessed with balance tests in the MACE?

Hearing ability
Visual acuity
Cognitive ability
Coordination and equilibrium (Correct answer)

Correct answer: Coordination and equilibrium

Balance tests, such as tandem gait or standing on one leg, are included in the MACE to assess an individual's coordination and equilibrium. Concussions can disrupt the brain's ability to process sensory information and control motor movements, leading to impaired balance and an increased risk of falls.

Question 31: How should a medic or corpsman manage a concussed service member in a combat environment?

Only evacuate for loss of consciousness
Administer pain medication and return to duty
Ignore the concussion and continue the mission
Conduct MACE assessment, ensure safety from further injury, monitor for red flag symptoms, evacuate if indicated, and document all findings (Correct answer)

Correct answer: Conduct MACE assessment, ensure safety from further injury, monitor for red flag symptoms, evacuate if indicated, and document all findings

Combat concussion management requires balancing tactical needs with medical care: conducting rapid assessment, ensuring the service member is in a safe location, monitoring for deterioration, making evacuation decisions, and documenting everything.

Question 32: What distinguishes combat-related TBI from sports concussion?

Combat TBI often involves blast mechanisms, polytrauma, comorbid PTSD, delayed presentation, and austere treatment environments (Correct answer)
Sports concussion is never serious
Combat TBI is always more severe
There is no difference

Correct answer: Combat TBI often involves blast mechanisms, polytrauma, comorbid PTSD, delayed presentation, and austere treatment environments

Combat TBI differs from sports concussion in mechanism (blast vs. impact), comorbidities (PTSD, pain, polytrauma), diagnostic challenges (delayed presentation, overlapping symptoms), and treatment context (operational environment vs. clinic).

Question 33: How does sleep disruption affect concussion recovery?

Only deep sleep matters
Concussion patients should avoid all sleep
Sleep has no effect on brain recovery
Poor sleep impairs the brain's glymphatic clearance system and metabolic recovery, potentially prolonging symptoms and delaying healing (Correct answer)

Correct answer: Poor sleep impairs the brain's glymphatic clearance system and metabolic recovery, potentially prolonging symptoms and delaying healing

Sleep is critical for concussion recovery: the glymphatic system clears metabolic waste during sleep, and disrupted sleep impairs cognitive recovery, mood regulation, and pain processing, creating a vicious cycle.

Question 34: Which component is NOT part of the MACE neurological examination?

Symptom evaluation
Physical endurance test (Correct answer)
Cognitive screening
Neurological screening

Correct answer: Physical endurance test

The MACE focuses on neurological and cognitive assessments relevant to concussion, such as symptom evaluation, cognitive screening (memory, orientation), and neurological screening (balance, coordination). A physical endurance test, which measures stamina and physical exertion, is not a component of the MACE neurological examination as it does not directly assess concussion-related brain function.

Question 35: What is second impact syndrome?

Getting two concussions in a career
A scoring term in boxing
Being hit twice in the same game
A rare but potentially fatal condition where a second concussion occurs before the first has fully resolved, causing rapid brain swelling (Correct answer)

Correct answer: A rare but potentially fatal condition where a second concussion occurs before the first has fully resolved, causing rapid brain swelling

Second impact syndrome occurs when the brain, still metabolically vulnerable from a prior concussion, sustains another impact. This can trigger catastrophic cerebral edema with potentially fatal brain herniation.

Question 36: How do blast exposure meters/sensors work?

They detect chemical agents
They measure wind speed
Wearable devices that measure and record blast overpressure exposure levels to track cumulative exposure and trigger medical evaluations (Correct answer)
They monitor heart rate

Correct answer: Wearable devices that measure and record blast overpressure exposure levels to track cumulative exposure and trigger medical evaluations

Blast sensors worn on helmets or body armor measure peak overpressure, impulse duration, and direction of blast waves, creating an exposure record. Data helps establish exposure thresholds and triggers MACE assessment when levels are concerning.

Question 37: What is the primary purpose of the Military Acute Concussion Evaluation (MACE)?

To evaluate acute concussions (Correct answer)
To measure physical fitness
To assess chronic traumatic brain injury
To diagnose mental health disorders

Correct answer: To evaluate acute concussions

The Military Acute Concussion Evaluation (MACE) is specifically designed as a standardized tool for healthcare providers to assess service members immediately following a suspected concussion. Its primary purpose is to identify and evaluate the acute symptoms and cognitive deficits associated with a recent mild traumatic brain injury. This allows for timely diagnosis and appropriate management.

Question 38: What documentation is required throughout the concussion recovery process?

Only the final clearance needs to be documented
Only the initial assessment needs documentation
Documentation is optional during recovery
Initial MACE scores, serial symptom checklists, follow-up MACE scores, activity progression notes, and final return-to-duty clearance documentation (Correct answer)

Correct answer: Initial MACE scores, serial symptom checklists, follow-up MACE scores, activity progression notes, and final return-to-duty clearance documentation

Comprehensive documentation tracks the entire recovery: initial assessment, serial symptom monitoring, repeat cognitive testing, progressive activity tolerance, and final clearance. This record supports medical decisions and disability claims if needed.

Question 39: What is the dual diagnosis challenge of TBI and PTSD in military populations?

TBI and PTSD share overlapping symptoms (sleep disturbance, concentration problems, irritability), making differential diagnosis and treatment complex (Correct answer)
Only one condition can be diagnosed
Treatment for one always cures the other
TBI and PTSD never co-occur

Correct answer: TBI and PTSD share overlapping symptoms (sleep disturbance, concentration problems, irritability), making differential diagnosis and treatment complex

TBI and PTSD frequently co-occur in combat veterans and share symptoms including concentration difficulty, irritability, sleep disruption, and memory problems. Accurate diagnosis requires careful evaluation of symptom onset, mechanism, and course.

Question 40: What sleep disturbances are associated with concussion?

Only excessive sleepiness occurs
Only insomnia occurs
Concussion does not affect sleep
Difficulty falling asleep (insomnia), excessive sleepiness, fragmented sleep, altered sleep-wake cycles, and increased or decreased total sleep time (Correct answer)

Correct answer: Difficulty falling asleep (insomnia), excessive sleepiness, fragmented sleep, altered sleep-wake cycles, and increased or decreased total sleep time

Sleep disruption after concussion can manifest as both too much and too little sleep. Disrupted sleep-wake regulation, difficulty initiating sleep, frequent awakenings, and daytime drowsiness are all common and impair recovery.

Military Acute Concussion Evaluation 2 (MACE 2)

The MACE 2 is a standardized, multimodal tool used by military healthcare providers to evaluate concussion in service members, covering history and screening, symptom reporting, neurological examination, cognitive assessment, and vestibular/ocular-motor screening.

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60 min

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80%

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