MKSAP quiz on head injuries


Case 1: Headache and vomiting after fall

A 34-year-old man is evaluated in the emergency department for worsening headache, nausea, and two episodes of vomiting 2 hours after hitting his head in a fall from the top of a 6-foot ladder.

On physical examination, temperature is normal, blood pressure is 128/84 mm Hg, pulse rate is 86/min, and respiration rate is 14/min. The patient's Glasgow Coma Scale score is 15/15.

Which of the following is the most appropriate immediate step in management?

A. Head CT with contrast
B. Head CT without contrast
C. Hospital observation
D. MRI of the brain

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Case 2: Soccer injury

An 18-year-old man is evaluated for recurrent headaches 1 week after falling on his head during a soccer match at his high school. The patient reports being “dazed” for 15 minutes after the fall but never losing consciousness. Findings from a sideline examination were unremarkable, and the patient was removed from play. Given the temporary alteration in consciousness, a follow-up examination with his internist was recommended. He developed headaches the morning after the injury that for 3 days were severe, global, throbbing, and associated with nausea and dizziness; the nausea and dizziness have gradually resolved, and for the past 2 days, the headache pain has been controlled with acetaminophen. He has had no cognitive symptoms but has not yet resumed school or sports activities.

Results of physical examination, including vital signs and neurologic examination findings, are unremarkable.

Which of the following is the most appropriate management?

A. Obtain a CT of the head
B. Obtain an MRI of the brain
C. Prohibit contact sports
D. Restrict classroom participation

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Case 3: Blurred vision after assault

A 44-year-old man is evaluated in the emergency department for a severe global headache and blurred vision. Two hours ago, he was struck with a pipe in the right frontotemporal region and anterior neck and knocked to the ground but did not lose consciousness. While describing the assault, the patient becomes stuporous.

On physical examination, blood pressure is 150/100 mm Hg, pulse rate is 50/min, and respiration rate is 10/min. Continued stupor is noted, as are right pupillary dilation, palsy of the oculomotor nerve (cranial nerve III), and an extensor plantar response on the left. The patient withdraws from pain more weakly on the left than the right. No other cranial nerve abnormalities are detected.

Which of the following is the most likely diagnosis?

A. Epidural hematoma
B. Left internal carotid artery dissection
C. Postconcussion syndrome
D. Posttraumatic seizure

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Case 4: Former pro football player

A 48-year-old man is evaluated for increasing depression and suicidal ideation. He reports experiencing feelings of hopelessness, lack of initiative, and general disinterest over the past 5 years that recently have worsened and are now accompanied by mood swings, irritability, impatience, verbal abuse, and physical aggression. Thoughts of death and suicide often have been present in the past month. His gait has become slow and shuffling, and his balance is increasingly impaired. His wife says he is more forgetful than ever and unable to perform home repairs that he previously accomplished easily. He has had no hallucinations or delusions. The patient is retired from a 13-year career playing professional football. Other than minor football injuries, he has no significant medical history and has an unremarkable family history, including no neurologic and psychological disorders. The patient takes no medication.

On physical examination, vital signs are normal. Neurologic examination shows slow processing speed, mild dysarthria, slowed rapid alternating movements bilaterally, and a wide-based gait with decreased foot-floor clearance. The patient scores 20/30 on the Montreal Cognitive Assessment, losing points in the visuospatial/executive function, attention, orientation, and delayed recall sections.

Which of the following is the most likely diagnosis?

A. Chronic traumatic encephalopathy
B. Dementia with Lewy bodies
C. Depression-related cognitive impairment
D. Parkinson disease

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Case 5: Car accident

A 32-year-old woman is evaluated in the emergency department 30 minutes after a motor vehicle accident in which she struck her head on the steering wheel. She is awake and conversant and has no major symptoms aside from a mild headache. She is at 23 weeks' gestation of her second pregnancy. She has been receiving routine prenatal care, and her pregnancy has been uncomplicated. Her only medication is a prenatal vitamin.

On physical examination, the patient is in neck immobilization. Temperature is 37.1 °C (98.7 °F), blood pressure is 111/63 mm Hg, pulse rate is 76/min, and respiration rate is 12/min. BMI is 24. There is a contusion on the upper forehead but no other evidence of trauma. The abdomen shows normal changes of pregnancy but is otherwise normal. The remainder of the physical and neurologic examinations is unremarkable.

Initial laboratory studies show a serum sodium level of 131 mEq/L (131 mmol/L); the remainder of the electrolytes, blood urea nitrogen, and serum creatinine are normal.

Which of the following is the most likely cause of this patient's decrease in her serum sodium level?

A. Cerebral salt wasting
B. Normal physiologic changes of pregnancy
C. Pituitary apoplexy
D. Syndrome of inappropriate antidiuretic hormone secretion

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Answers and commentary

Case 1

Correct answer: B. Head CT without contrast.

This patient should have CT of the head without contrast. The American College of Emergency Physicians and the Centers for Disease Control and Prevention have published guidelines for management of mild traumatic brain injury (TBI). Their recommendation is to consider a noncontrast head CT in patients with TBI who have had no loss of consciousness or posttraumatic amnesia but have a focal neurologic deficit, vomiting, severe headache, physical signs of a basilar skull fracture, Glasgow Coma Scale score less than 15, coagulopathy, or a dangerous mechanism of injury, such as ejection from a motor vehicle or a falling from a height of more than 3 feet. This patient sustained a TBI with a dangerous mechanism of injury several hours ago and has developed symptoms (worsening headache and vomiting) mentioned in the guideline. Therefore, noncontrast CT of the head is indicated. A finding of parenchymal, subdural, or epidural hemorrhage requires emergent neurosurgical evaluation and consideration of possible hematoma evacuation.

In the setting of acute head trauma, head CT without contrast is preferable to head CT with contrast and brain MRI because of its lower cost and wider availability. Contrast administration aids in the assessment of certain malignant and vascular lesions of the brain but adds nothing to the evaluation of acute head trauma. Head CT without contrast is also very sensitive for detecting skull fracture or acute hemorrhage, and a CT scan generally requires shorter examination times than a brain MRI requires, both important factors in the evaluation of a patient with acute head injury and symptoms of potential deterioration.

Hospital observation without first ruling out intracranial hemorrhage is inappropriate management of TBI. Untreated intracranial hemorrhage can lead to an accumulation of blood and edema within the skull, which can cause compression or destruction of brain tissue, increased intracranial pressure, and even herniation and death.

Key Point

  • Head CT without contrast is the appropriate imaging procedure for selected patients with acute traumatic brain injury.

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Case 2

Correct answer: C. Prohibit contact sports.

Contact sports should be prohibited for this patient with symptoms after sustaining a mild traumatic brain injury, which occurred when head trauma resulted in a transient alteration of neurologic function. The patient exhibited the typical physical symptoms of this type of injury, including headache, dizziness, and nausea. Although the symptoms have largely resolved, he still requires acetaminophen to control headache pain. Prohibiting contact sports is recommended for a patient who is still symptomatic. This restriction should remain in place even when the patient is in an asymptomatic state after taking medication. Not until the patient is asymptomatic without taking any medication should a return to contact sports be considered.

In the presence of normal findings on physical examination, a head CT scan or MRI of the brain is unlikely to provide any useful information and thus has no role. A noncontrast head CT scan is recommended in the setting of acute head injury when skull fracture or intracranial hemorrhage is suspected. Risk factors for these findings include prolonged loss of consciousness, posttraumatic amnesia, focal neurologic deficit(s), vomiting, severe headache, physical evidence of a basilar skull fracture, a Glasgow Coma Scale score less than 15, coagulopathy, or a dangerous mechanism of injury. MRI of the brain may be more sensitive in the detection of small areas of parenchymal damage or hemorrhage in the patient who is seen days or weeks after an injury, but suspicion of such damage would be low in this patient who has shown significant improvement 1 week after the trauma.

Gradual reintroduction of cognitive and normal physical activities is recommended for patients with concussion. Those with significant cognitive symptoms or neuropsychological examination deficits should have restrictions placed on cognitive activity. Immediate resumption of normal levels of cognitive activity (such as full days of classroom work) may delay recovery in some patients. Typically, cognitive rest is recommended for 3 to 7 days, followed by gradual reintroduction of cognitive activity periods. These periods initially should be limited to the threshold of concussion symptom aggravation but, over time, should be lengthened. Given the wide variability of recovery timeframes, management must be individualized. In this patient without any cognitive or significant physical symptoms 1 week after the injury, returning to school is appropriate, and restriction of classroom participation is not required.

Key Point

  • Contact sports should be prohibited in patients who are symptomatic after sustaining a mild traumatic brain injury.

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Case 3

Correct answer: A. Epidural hematoma.

This patient most likely has an epidural hematoma. Traumatic epidural hematoma classically presents with precipitous neurologic decline after head trauma. Most patients with this diagnosis have a skull fracture with associated rupture of an underlying artery, typically the middle meningeal artery. Blood under arterial pressure accumulates between the inner table of the skull and the dural membranes. The most common symptoms are severe headache and vomiting. Impairment of consciousness may develop immediately or after a lucid interval. Uncal or subfalcine brain herniation can occur and is characterized by ipsilateral oculomotor nerve (cranial nerve III) palsy, contralateral paresis, and stupor or coma. Hypertension with bradycardia (the Cushing response) can be another sign of increased intracranial pressure. A CT scan of the head confirms the diagnosis, and immediate surgical evacuation is required. Mortality rates are commonly reported to be 10% to 20%.

Dissection of the left internal carotid artery typically results in ipsilateral Horner syndrome with ptosis, miosis, and anhidrosis but not oculomotor nerve (cranial nerve III) palsy. Contralateral hemiparesis could result if a secondary stroke were to occur in the left frontal lobe after the dissection, but rapidly declining consciousness would be unexpected.

Postconcussion syndrome is defined by a constellation of neurologic, psychological, and constitutional symptoms without significant abnormalities on physical examination. Minor neurologic findings noted on the examination of a patient with mild traumatic brain injury may include ocular convergence insufficiency or mild ataxia, but typically examination findings are normal. This patient's clinical findings do not fit this pattern.

Seizures occur in approximately 5% of persons hospitalized for acute head trauma. They may be classified as “immediate” if occurring within the first 24 hours, “early” if noted within the first week, or “late” if occurring more than 1 week after the injury. Half of the seizures occurring within the first week will occur in the first 24 hours, and the risk decreases with time. Some correlation between the severity of injury and the risk of posttraumatic seizures exists. This patient shows no signs of involuntary motor activity, so convulsive status epilepticus is not present. Nonconvulsive status epilepticus might manifest as stupor, but the presence of focal cranial nerve and motor deficits in this patient is more indicative of a progressive structural lesion.

Key Point

  • Traumatic epidural hematoma classically presents with precipitous neurologic decline after head trauma; common symptoms are severe headache and vomiting, with possible impairment of consciousness developing immediately or after a lucid interval.

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Case 4

Correct answer: A. Chronic traumatic encephalopathy.

The most likely diagnosis for this patient is chronic traumatic encephalopathy. Chronic traumatic encephalopathy is a progressive neurodegenerative disorder triggered by repetitive mild head injury that has most often been described in military combat veterans and athletes with a history of multiple concussions and subconcussions. This patient's career as a professional football player would have made him particularly susceptible to this type of injury. Clinical symptoms typically manifest years or decades after repeated head trauma and present insidiously. Behavioral symptoms are common and include depression, suicidal ideation, apathy, and irritability. Disinhibition, impulsivity, and aggression can also occur in the later stages. Cognitive symptoms include problems with memory, attention, concentration, and executive function. With disease progression, poor judgment and poor insight become more prominent. Parkinsonism, disturbance of gait, and speech abnormalities often occur later in the disease course.

Although this patient exhibits mild parkinsonism on clinical examination, he lacks other features to support a diagnosis of dementia with Lewy bodies, such as fluctuating cognition, visual hallucinations, rapid eye movement sleep behavior disorder, and autonomic dysfunction. In addition, his age at symptom onset is unusual for dementia with Lewy bodies, which typically presents in the sixth decade of life or later.

Depression-related cognitive impairment refers to the cognitive deficits associated with depression and most often is characterized by frontal-subcortical dysfunction and slowed processing speed. Cognitive symptoms improve with treatment of depression. The patient has depression accompanied by suicidal ideation, but his history and constellation of additional neurologic and behavioral symptoms are more suggestive of chronic traumatic encephalopathy.

Parkinsonism tends to occur in chronic traumatic encephalopathy during the later stages of the disease. Comorbid neurodegenerative disease, such as Alzheimer disease, Lewy body disease, and Parkinson disease, can be seen in a percentage of patients with chronic traumatic encephalopathy at autopsy, and some evidence suggests that repetitive head injury is associated with increased risk of these disorders. This patient has slow and shuffling gait and bradykinesia but lacks the cardinal signs of idiopathic Parkinson disease, including resting tremor or rigidity, a unilateral onset, and asymmetric parkinsonism. The most likely diagnosis for his clinical syndrome of cognitive, behavioral, and motor decline is chronic traumatic encephalopathy.

Key Point

  • Chronic traumatic encephalopathy is a progressive neurodegenerative disorder triggered by repetitive mild head injury as occurs in military combat veterans and athletes with a history of multiple concussions and subconcussions.

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Case 5

Correct answer: B. Normal physiologic changes of pregnancy.

Normal physiologic changes of pregnancy are the most likely cause of this pregnant patient's decrease in her serum sodium level. While the plasma volume increases during pregnancy, water retention exceeds the concomitant sodium retention, resulting in mild hypo-osmolality and hyponatremia. The plasma osmolality typically decreases by 8 to 10 mOsm/kg H2O, and the serum sodium decreases by 4.0 mEq/L (4.0 mmol/L). These hormonally mediated changes in plasma osmolality and serum sodium do not require therapy and resolve following delivery.

Cerebral salt wasting can be mistaken for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and can occur in response to central nervous system disease (particularly subarachnoid hemorrhage) and closed head injury. It is associated with an increased loss of sodium by the kidney, resulting in hyponatremia. However, these changes occur over a longer timeframe than seen in this patient with recent head trauma.

Pituitary apoplexy is acute hemorrhage into the pituitary gland and would be a consideration in this patient. If severe, it may cause headache, vision changes due to ocular nerve compression, and hypopituitarism. All pituitary hormonal deficiencies can occur, including adrenocorticotropic hormone (ACTH) deficiency, which may lead to cortisol deficiency and hypotension if it occurs rapidly. Although the resulting cortisol deficiency may result in mild hyponatremia, this would not occur immediately after injury. Additionally, this patient has a normal blood pressure for pregnancy and no other symptoms or clinical findings suggesting this diagnosis.

Neurologic conditions such as a closed head injury from a motor vehicle accident can cause the SIADH, but hyponatremia would not develop acutely upon initial presentation as in this patient.

Key Point

  • While the plasma volume increases during pregnancy, water retention exceeds the concomitant sodium retention, resulting in mild hypo-osmolality and hyponatremia; these hormonally mediated changes do not need direct therapy and resolve following delivery.