Head Injury

Pathophysiology

100

10mmHg >20 = uncontrollable ICP (refractory to Tx) If ICP is not controlled, herniation syndromes can occur, resulting in brainstem compression and subsequent cardiorespiratory arrest.

What is a normal ICP?

200

Methods to reduce elevated ICP include hyperventilation, use of osmotic and diuretic agents, and CSF drainage.

What are simple methods used to reduce elevated ICP?

300

Congestive brain swelling and cerebral edema. Congestive brain swelling results from an increased intracranial blood volume, most likely caused by vasodilation, which occurs as a compensatory mechanism to maintain optimal CBF in the presence of increased metabolic needs of the damaged brain tissue. Cerebral edema is an increase in brain volume caused by an absolute increase in cerebral tissue water content.

What are the two primary types of brain swelling that occur after head injury? please define each

400

Progressive hypertension associated with bradycardia and diminished respiratory effort which is a specific response to acute, potentially lethal increases in ICP.

What is Cushing's Reflex?

500

Uncal herniation, which is a form of transtentorial herniation associated with traumatic extra-axial hematomas in the lateral middle fossa or the temporal lobe

What is the most common clinically significant traumatic herniation syndrome? Define it

Head Trauma

100

10%

What % of patients with head injury have sustained moderate TBI?

200

Patients often have experienced a change in consciousness at the time of injury, a progressive headache, Post-traumatic seizures, vomiting, and post-traumatic amnesia GCS 9-13

What variety of clinical presentations can occur with moderate head injury? what is the GCS score that corresponds to moderate head injury?

300

ED trephination and hematoma evacuation of any amenable lesion should be considered.

What is the management of the patient who develops symptoms consistent with herniation syndrome not reversed by acute hyperventilation and mannitol when a neurosurgeon is not available?

400

Clinical signs and symptoms of minor TBI include balance deficits, impaired verbal memory, delayed language comprehension, slowed speech, amnesia regarding the impact, a period of disordered awareness (with or without LOC), and a finite period of post-trauma amnesia (PTA).

What are clinical signs and symptoms of minor TBI?

500

The persistent symptoms after Mild head trauma that generally include the domains of cognitive, psychomotor, and behavioral performance. S/Sx: headache, sensory sensitivity, memory or concentration difficulties, irritability, sleep disturbances, dizziness, depression, and amnesia regarding the traumatic event

What is post-concussive syndrome (PCS)? what are the s/sx of PCS?

Pediatric Head Injury

100

TBI

What accounts for the largest source of childhood mortality and morbidity after trauma

200

Most PTSs occur within the first 24 hours and do not predict seizures later in the post-traumatic period

When do post-traumatic seizures in children with severe or moderate head injury?

300

These lesions are associated with scalp injuries and skull fractures but no other symptoms. In toddlers the only symptom of an intracranial injury may be irritability.

What is the clinical presentation of post-traumatic intracranial lesions in infants who have sustained moderate or severe TBI?

400

Postconcussive blindness, is usually associated with impact to the back of the head.

What is a serious complication of concussive injuries in children?

500

occur with concentrated forces that indent the skull. These fractures are unique to infants and appear as multiple indentations in the skull with no significant bone discontinuity.

What are Ping-Pong fractures?

Potpourri

100

wounds that are caused by an impact that occurs at an oblique angle to the skull. If the missile has high velocity but low energy, it can travel around the skull under the scalp without passing through the skull.

What are tangential wounds?

200

Perforating wounds are usually caused by high-velocity projectiles, which cause through-and-through injuries of the brain with an entrance and an exit wound.

What are Perforating wounds?

300

Penetrating missile wounds are produced with moderate- to high-velocity projectiles discharged at close range.

What are Penetrating missile wounds?

400

SVT

What is the most common cardiac dysrhythmia after head injury?

500

Cranial osteomyelitis can occur after penetrating injury to the skull. The clinical manifestations include pain, tenderness, swelling, and warmth at the infected site.

What are the clinical manifestations of Cranial osteomyelitis?

Miscellaneous

100

Hypertension, alkalosis, and hypocarbia promote cerebral vasoconstriction. Hypotension, acidosis, and hypercarbia cause cerebral vasodilation. The physiologic response of blood vessels to P co 2 is the rationale for the acute use of brief hyperventilation to control increased intracranial pressure (ICP) after head injury. As P co 2 decreases with hyperventilation, cerebral vasoconstriction occurs.

What affects the diameter of cerebral vessels and how is it affected?

200

Cerebral vasoactivity is very sensitive to changes in systemic carbon dioxide and oxygen partial pressures (P co 2 and P o 2 , respectively)

What 2 systemic elements affect cerebral vessels' diameter?

300

CPP=MAP−ICP

What is Cerebral perfusion pressure?

400

CBF is maintained at constant levels with a mean arterial pressure (MAP) of 60 to 150 mm Hg. Outside this range, the CBF varies linearly with MAP

What is the range of cerebral blood flow (CBF) for autoregulation?

500

The sum of the volume of brain, CSF, and blood within the cranium will remain constant. If the volume of any of these components increases, the volume of another must decrease for a constant ICP to be maintained.

What is the Monro-Kellie doctrine in terms of ICP?