Head Injuries Flashcards
What is a closed head injury?
Damage to the brain without any fracture of the skull and/or penetration of dura; most often results from blunt trauma.
What is an open head injury?
Disruption of cranial vault with opening through skin and cranial bones to expose damaged brain; most often associated with firearm wounds, stab wounds, and motor vehicle or occupational accidents.
What are the two main mechanisms of trauma?
- Blunt trauma
- Penetrating trauma
What is direct trauma in the context of blunt trauma?
When a moving object hits the head, e.g., blow with a stick, baseball, or falling block of wood.
What is deceleration of the head?
When a moving head impacts a fixed object, e.g., falling on the ground.
What is inertial trauma?
Causes rotational acceleration or deceleration of the head, leading to shearing or stretching of brain tissue.
What can penetrating trauma involve?
Heavy sharp objects such as a knife or penetrating objects like a missile.
What are the layers of the scalp?
- Hairy skin
- Subcutaneous fat and dense connective tissue
- Galea aponeurotica
- Loose areolar connective tissue
- Periosteum
What are the types of scalp injuries?
- Lacerations
- Torn flap wounds
- Cut wounds
- Firearm wounds
What is a common complication of scalp wounds?
Hemorrhage due to rich blood supply and fibrous tissue preventing vasospasm.
What factors affect skull fractures?
- Force of the impact
- Site of the impact
- Striking surface area
- Head coverings
- Support of the head
- Elasticity
- Edge of causative instrument
What are the types of skull fractures?
- Fissure fracture
- Depressed fracture
- Comminuted fracture
- Cut fracture
What characterizes a fissure fracture?
It is linear, with no bone defect, occurs at the site of impact, and can extend along lines of anatomical weakness.
What is a polar fracture?
Occurs at the most bulging poles when the head is supported and receives trauma opposite to the site of support.
What is a depressed fracture?
Caused by a heavy blunt object with a localized striking surface and high momentum, occurring at the site of impact.
What is a comminuted fracture?
Characterized by radiating fissures connected by concentric fracture rings, often caused by a heavy blunt object.
What are the four types of intracranial hemorrhage (ICH)?
- Extradural (epidural) hemorrhage (EDH)
- Subdural hemorrhage (SDH)
- Subarachnoid hemorrhage (SAH)
- Pathological ICH
What is extradural (epidural) hemorrhage (EDH)?
Arterial blood accumulates between the periosteal layer of the dura and the inner skull table, typically traumatic.
What is subdural hemorrhage (SDH)?
Blood accumulates between the meningeal layer of the dura and arachnoid matter, often due to inertial trauma.
What is the difference between acute and chronic subdural hemorrhage?
- Acute SDH: Caused by sudden jarring or rotation of the head
- Chronic SDH: Caused by repeated minor trauma, more common in elderly or those with prolonged bleeding times
What is subarachnoid hemorrhage (SAH)?
Hemorrhage in the subarachnoid space, often due to the rupture of an aneurysm or extension of pathological intracerebral hemorrhage.
What is the clinical presentation of a traumatic intracranial hemorrhage?
May present with coma, fever, pinpoint pupils, and muscle paralysis.
What is concussion?
A clinical state of transient loss of consciousness due to temporary impaired cerebral functions following head trauma.
What is the treatment for concussion?
Hospitalization and observation for vital signs, pupil size, muscle tone, and symptoms for 48 hours.
What is the lucid interval?
A stage of consciousness between unconsciousness and full consciousness.
What is amnesia in the context of head injuries?
Loss of events just before or after the injury.
What is the recommended treatment for a patient with a concussion?
Hospitalization and observation for vital signs, pupil size, muscle tone, reflexes for 48 hours.
What is a lucid interval?
A stage of consciousness between the unconsciousness of concussion and that of compression where the patient can walk and speak.
What occurs after the recovery of a patient from concussion?
Bleeding starts and increases gradually leading to another stage of loss of consciousness due to cerebral compression.
What is the medico-legal importance of the lucid interval?
Patients must be carefully examined and monitored for 48 hours; negligence may be claimed if a patient is discharged and dies at home.
What does DAI stand for?
Diffuse Axonal Injury.
What is the pathophysiology of DAI?
Disruption of the brain’s regular communication and chemical processes due to shearing movement at the gray-white matter interface.
What are the causes of cerebral compression?
- Intracranial hemorrhage
- Depressed skull fracture
- Intracranial tumors
- Infections
- Brain edema
- CSF obstruction (hydrocephalus)
- Increased production (meningitis)
What are the stages of cerebral compression?
- Irritation stage
- Paralytic stage
- Coning (tonsillar herniation) stage
What are the clinical signs of traumatic cerebral compression?
- History of recent head trauma
- Gradual loss of consciousness
- Irritability or disorientation
- Headache, projectile vomiting, blurred vision
- Cushing’s triad
What is Cushing’s triad?
Slow full regular pulse, hypertension, low breathing which may be irregular.
What signs of lateralization may occur with cerebral compression?
- Unequal pupil size
- Contra-lateral hypertonia & hyperreflexia then hypotonia & hyporeflexia
What is the treatment for cerebral compression?
Decompression operation to remove the cause of compression.
What are long term complications of head injuries?
- Post traumatic epilepsy
- Meningitis and brain abscess
- Permanent disability
- Cranial nerve damage
- Cognitive disabilities
- Sensory problems
- Language difficulties
- Personality changes
- Alzheimer’s, Parkinson’s disease, or Dementia
What are the early causes of death in head injuries?
- Cerebral lacerations or contusions
- Diffuse axonal injury
- Cerebral compression with brain herniation
- Fatal concussion
What are the delayed causes of death in head injuries?
- Septic complications
- Epilepsy
