Trauma to the Nervous System

Question 1

A more diffuse force applied to the skull typically produces a ___ skull fracture, while a more local or localized force causes a ___ skull fracture.

Answer 1

Linear; depressed

Question 2

A severe skull fracture may be associated with an underlying ___ of the brain.

Answer 2

Contusion or laceration

Question 3

Fractures at the skull base, face, or orbit can entrap or compress ___.

Answer 3

Cranial nerves

Question 4

Rx skull fracture?

Answer 4

Surgical removal of bone fragments and debris, closure of any dural tears

Question 5

What are brain contusions?

Answer 5

Superficial hemorrhages at the tops of cortical gyri near the point of impact (coup) or more remotely in the brain (contrecoup) from movements of the brain within the skull

Question 6

Most common locations of brain contusions?

Answer 6

Basal or ventral surfaces of the frontal and anterior temporal lobes, where the bony skull is roughened or protuberant

Question 7

What types of acceleration injuries cause brain contusions?

Answer 7

Angular or rotation, not linear

Question 8

What is cerebral autoregulation?

Answer 8

Vasoconstriction or vasodilation to preserve optimal cerebral blood flow despite fluctuation in system BP over a range of 60-140 mm Hg (MAP)

Question 9

In the setting of severely increased ICP, Cushing’s response may be observed - what happens?

Answer 9

Elevation of systemic BP to preserve cerebral blood flow + bradycardia and slowed RR

Question 10

Types of herniation that can occur with increased ICP?

Answer 10

1. Subfalcine -> cingulate gyrus pushed under the falx cerebri
2. Uncal -> medial temporal lobe compressed against the midbrain
3. Tonsillar -> shifting of lower brain stem and cerebellar tonsils down the foramen magnum

Question 11

Which type of herniation causes a fixed and dilated ipsilateral pupil?

Answer 11

Uncal herniation

Question 12

An acute subdural hematoma occurs after the focal laceration of ___, which empty into larger venous sinuses of the brain.

Answer 12

Bridging cortical veins

Question 13

R acute subdural?

Answer 13

Surgical removal of the hematoma if indicated

Question 14

Cause of epidural hematoma?

Answer 14

Rupture of meningeal artery or vein, often from a temporal bone fracture

Question 15

Three components of intracranial volume?

Answer 15

Brain
Vascular
CSF

Question 16

Why does mechanical hyperventilation decrease ICP?

Answer 16

Reduces arterial pCO2 -> cerebral arterial vasoconstriction -> reduced intracranial blood volume -> reduced ICP

Question 17

Calculate GCS?

Answer 17

Eye opening: 1-4 -> none, to pain, to verbal command, spontaneously

Motor response: 1-6 -> none, abnormal extension (decerebrate rigidity), abnormal flexion (decorticate rigidity) -> withdraws from pain (flexion) -> localizes pain -> obeys verbal commands

Verbal response: 1-5 -> no response, makes incomprehensible sounds -> uses inappropriate words -> disoriented and converses -> oriented and converses

Question 18

Presentation of a high cervical spinal cord lesion?

Answer 18

Quadriplegia with respiratory paralysis (if C3-C5 are involved) +/- sympathetic involvement (bradycardia, fluctuating BP, hypothermia)

Question 19

Cause and presentation of central cervical cord syndrome?

Answer 19

Elderly patients with advanced degenerative arthritis of the spinal colum who fall forward and hyperextend the neck -> central hemorrhage of cervical SC -> predominant weakness of the upper limbs (medial CST and cervical anterior horn cells)

Question 20

Neurological recovery is more likely if ___ are begun within 8 hours of spinal cord injury.

Answer 20

High-dose IV corticosteroids (dexamethasone)