Case Index

PATIENT CASE STUDIES
Case 9 2/22/99 Patient


Case discussion

This 48 year-old man was found poorly responsive in the street, the apparent victim of a hit-and-run driver.
He was intubated and transferred to UCDMC.

On examination he had a cephalhematoma and a laceration over the left forehead and ecchymoses over the left flank. BP was 160/90, pulse rate was 110 and temperature was 37 C. He was intubated and required mechanical ventilation. He had occasional spontaneous respirations. He had remained comatose since initial evaluation in the field and was not responding to verbal stimuli. There was no spontaneous eye opening. He opened his eyes occasionally to painful stimuli but no verbal responses. There was a dilated left pupil fixed to light. With oculocephalic testing the left eye failed to move on turning the head to the left whereas the right eye deviated to the right. With painful stimuli, there was decerebrate posturing of the left extremities and withdrawing and flexing of other extremities with pain localization. DTRs were diffusely brisk 3+, brisker on the left side. There was clonus at the left ankle. Both plantars were extensor.

Pathologic Case Correlate: Neuropath Case 3

Group 4:
  1. Summarize the Case in 1-2 sentences.

    2. A 48-year-old male victim of a hit and run accident is comatose with impaired respiration. Physical exam shows signs of increased intracranial pressure due to enclosed space of the skull.

    you may also say patient had a closed head injury and to include the findings of dilated left pupil and left third nerve palsy and left hemiparesis (signs of raised icp is not very specific and could mean many things); the summary should not include a diagnosis or pathogenesis (eg due to enclosed space of the skull); the summary is a summary of the course and physical signs as well as additional features that may help in dx.

  2. Discuss lesion localization on the basis of the physical examination.

    3. The lesion can be localized to the CNS.

    1. Compression of left CNIII. (comment: cranial nn are not part of the cns) Fixed dilated left pupil. comment: left third nerve (note pupillomotor fibers are on the periphery of the nerve bundle)
    2. Brainstem.
      Impaired respiration. Loss of doll’s eye reflex in left eye.

    failure for the left eye to move on turning the head to the left (i.e. adduction of the left eye) does not indicate a brain stem lesion; it suggests a left third nerve palsy.

    C. Upper Motor Neuron
    Brisk DTR, especially on the left side. Clonus of left ankle.
    Bilateral plantar extensor.

    bilateral corticospinal tracts worse on the right side of brain.

    D. Right cut below red nucleus and above the vestibular nucleus.
    Decerebrate posturing on the left side.
    you mean a lesion (not a necessarily a cut); at the midbrain level

  3. Discuss underlying pathogenesis on the basis of clinical course.

    4. Acute time course indicates either a vascular phenomena or infection.

    onset here is acute or sudden (it suggests trauma or vascular)

  4. Indicate one likely clinical diagnosis. List (or classify) alternative diagnoses.

    5. The most likely diagnosis is epidural hematoma of the left cerebral hemisphere secondary to craniocerebral trauma. This a more likely diagnosis as opposed to a subdural hematoma because of the shorter time course. Less likely diagnoses include abscess and tumor.

    comment: what about intracerebral hemorrhage comment: closed head injury with likely epidural hematoma causing transtentorial herniation

  5. Indicate 2 ancillary tests that would assist in confirming or refuting the clinical diagnosis. Indicate the test results that would confirm the clinical diagnosis.

    6. CT scan provides imaging for trauma and hemorrhage, and would readily reveal a hematoma. For tumor or abscess, an MRI would be a better choice. A lumbar puncture for culturing can reveal the presence of an infection.

    comment: only 2 tests are asked for; lp is contraindicated in a person who is herniating.

  6. Indicate complications of the disease and ancillary tests that would help evaluate them.

    7. Continued increase in pressure will lead eventually to brainstem herniation and death. This can be visualized by CT. An X-ray can be especially useful in a trauma because of the possibility of fracture of bones or rupture of other organs elsewhere in the body.

    comment good: other complications: coup contracoup injuries, axonal shear, intracerbral contusions, hemorrhage, spinal injuries and injuries to other organs.

  7. Discuss how the underlying pathophysiology is relevant in the management of this patient.

    8. The hematoma increases intra-cranial in the left upper hemisphere inducing a downward force on the brain, compressing the CN III nerve on the left side (tentorial herniation) and the brainstem (tonsillar herniation) predominantly on the left side. There is compression of the upper motor pathway against the edge of the tentorial hiatus which explains the diffuse increased DTR. Greater lateral compression of the right cortical pathway results in the decerebrate posturing on the left side.

    comment: right sided pathway is the right corticospinal pathway compressed at the level of the midbrain against the rough edge of the right side of the tentorium cerebelli (Kernohan's notch)

    Surgery must be performed immediately to remove the hematoma. Until then, Mannitol can decrease intracranial pressure by establishes an osmotic diuresis of brain tissue. Hyperventilation can reduce PCO2 causes vasoconstriction therefore reducing intra-cranial pressure. Blood pressure must be greater than intra-cranial pressure to insure perfusion.

    Pathophysiology of closed head injury is similar to that of ischemic stroke with cerebral ischemia. In this context maintenance of cerebral perfusion pressure is important to maintain cerebral blood flow.


Group 3:
  1. Summarize the Case in 1-2 sentences.

    2. 48 year old male victim of a hit and run presents with cephalohematoma and laceration on the left forehead. Examination showed the patient to be comatose (eyes open to painful stimuli, no verbal response) and placed on mechanical ventilation.

    Note summary should be a summary of onset and course. You should include that this 48 year old male suffered a closed head injury (more than just a cephalhematoma), calculate the glasgow coma scale, and indicate the presence of signs of herniation

  2. Discuss lesion localization on the basis of the physical examination.

    3. Mechanical ventilation (brainstem/cortex) Coma (Reticular Activation System) reaction to painful stimuli = sensory pathways intact decerebrate posturing of left extremities (diencephalon/midbrain) Left pupil was dilated (CN III compression/ midbrain lesion) and failed to move on doll's eye maneuver (brainstem depression, cortex depression) Right eye okay DTR's more brisk on left (UMN), clonus at left ankle (UMN) Plantars extensor (UMN)

    good; try to be brief

  3. Discuss underlying pathogenesis on the basis of clinical course.

    4. Trauma to left forehead could have resulted in a contrecoup lesion in the right cortex (UMN symptoms on left). Time course suggests a vascular versus a edematous process leading to an increase in intracranial pressure. This could result in a compression of the left CNIII as well as herniation leading to damage of the RAS in the medulla (coma and UMN signs).

    course really is an acute one here with progression, suggesting of traumatic/vacular pathogenesis including hemorrhage.

  4. Indicate one likely clinical diagnosis. List (or classify) alternative diagnoses.

    5. Right subdural hematoma epidural hematomas tend to cause more acute deterioration (arterial blood); differential includes subdural, intracerebral hemorrhage, seizure activity (subclinical)

  5. Indicate 2 ancillary tests that would assist in confirming or refuting the clinical diagnosis. Indicate the test results that would confirm the clinical diagnosis.

    6. CT - blood in brain Lumbar puncture - blood in CSF

    LP is contraindicated with a mass lesion; patient is likely to herniate. another test may be burr hole placement to measure ICP and release blood.

  6. Indicate complications of the disease and ancillary tests that would help evaluate them.

    7. Death, permanent brain damage

    also raised icp, herniation (Duret hemorrhages), cerebral anoxia, secondary to closed head injury, seizures, contrecoup injury with lacerations/contusions of brain, axonal shear injury in deep brain matter

  7. Discuss how the underlying pathophysiology is relevant in the management of this patient.

    8. Concerns about intracranial pressure. Treat with mannitol to reduce intracellular volume and hyperventilate to vasoconstrict.

    also: if epidural blood is present patient needs surgical relief to prevent herniation; an epidural hematoma is a surgical emergency; maintaining Cerebral perfusion pressure is important if ICP is high; hypervolemic and hypertensive therapies may be necessary (need determined by monitoring ICP); the pathophysiology of closed head injury is similar to that of cerebral ischemia (see chapter on cva in collins for pathophys).


Another Version:
  1. Summarize the Case in 1-2 sentences.

    2. A 48-year-old male victim of a hit and run accident presents with a closed head injury. He is comatose with impaired respiration; physical exam shows signs of increased intracranial pressure: dilated left pupil, left CNIII palsy, and left hemiparesis.

    good

  2. Discuss lesion localization on the basis of the physical examination.

    3. The physical exam is consistent with an acute space encroaching lesion over the left cerebral hemisphere resulting in left occulomotor nerve palsy, right cerebral peduncle damage to the pyramidal tract, medullary compression of the respiratory centers, midbrain compression and disruption of the reticular activating system, and non-specific involvement of the left pyramidal system.

    ok

  3. Discuss underlying pathogenesis on the basis of clinical course.

    4. The sudden onset of this condition suggests a lesion either vascular or traumatic.

    good

  4. Indicate one likely clinical diagnosis. List (or classify) alternative diagnoses.

    5. The most likely clinical diagnosis is closed head injury with likely epidural hematoma causing transtentoral herniation. Alternative diagnoses include: subdural hematoma, penetrating trauma, lacerating injury, hemorrhagic stroke, or ischemic stroke

    good

  5. Indicate 2 ancillary tests that would assist in confirming or refuting the clinical diagnosis. Indicate the test results that would confirm the clinical diagnosis.

    6. Two tests to order are a CT and caloric testing. While a MRI would offer better soft-tissue blood contrast, a CT scan would provide a much more rapid confirmation the diagnosis. Involvement of the vestibular system could be investigated with caloric testing. Imaging studies will often show a low-density mass (of blood) in overlying the lateral temporal convexity. The borders of this expanding mass will form a sharp angle with the inner skull surface. Caloric testing can confirm involvement of element's of the vestibular system. Note that lumbar puncture is contraindicated in patients with herniation, as a breach in the lower dura will allow an outlet for increased ICP, potentially causing continued flow of brain matter.

    too long

  6. Indicate complications of the disease and ancillary tests that would help evaluate them.

    7. The number one complication of epidural hematoma is increased intracranial pressure and resulting transtentorial herniation. This can result in:
    * Duret hemorrhages (rupture of penetrating branches of basilar artery and resulting hemorrhage in the mesencephalon and pons) - best visualized by MRI
    * Third nerve palsy - pupil exam, dolls eye maneuver
    * Coma (compression of the RAS) - Glasgow coma scale
    * Cardio-respiratory arrest (meduallary cardiopulmonary centers) - physical exam
    * Kernohan's notch (pressure groove on contralateral cerebral peduncal) - motor exam (hemiparesis ipsilateral to primary lesion)
    * Aqueductal compression (increased resistance to CSF outflow and obligatory increase in ICP) - MRI, CT, direct measurement of ICP

    Other traumatic complications include:
    Fractures - X-ray
    Organ injury - CT, MRI, physical exam
    Coup/Contra Coup injuries - CT, MRI
    Intracerbral contusions - CT, MRI
    Hemorrhage - CT, MRI, physical exam
    Spinal cord injuries - MRI, physical exam
    Axonal shear

    very good

  7. Discuss how the underlying pathophysiology is relevant in the management of this patient.

    8. Epidural hematomas present expanding mass lesions to soft tissue in a closed compartment. The rigidity of skull and dural surfaces leave few options for transmission of increasing intracranial pressure. Brain tissue near openings in the dural lining can herniate. In this patient, the increase in ICP applied downward force on the brain causing left sided tentorial herniation (compressing CN III) and tonsilar herniation (compressing the brainstem). The right-sided involvement is caused by compression of the midbrain right corticospinal pathway against the edge of the tentorium cerebelli at Kernohan's notch.

    Hypoxia resulting from reduced perfusion interferes with energy production in affected cells. With less ATP available, ion pumps in these cells begin to fail, causing a disruption in the normal maintenance of ion gradients and intracellular edema develops. This can lead to "electrical" failure of the cells and starts a cascade of events ending with irreversible damage and cell death.

    additional important point to make is that the management involves maintainence of Cerebral perfusion pressure by monitoring icp and bp and maintaining the CPP at over 70 mmHg