Closed-Head Injuries Going Beyond the Thud!. Brain Trauma Types Penetrating Intracranial Injuries...
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Transcript of Closed-Head Injuries Going Beyond the Thud!. Brain Trauma Types Penetrating Intracranial Injuries...
Closed-Head Injuries
Going Beyond the Thud!
Brain Trauma Types
• Penetrating Intracranial Injuries
• Closed Head Injuries
Motor Vehicle Accidents are leading cause in young people
38% of cases in young people attributed to alcohol/drug abuse
Increase in the elderly due to anticoagulant & antiplatelet drugs
Emedicine.medscape.com
Closed Head Injuries
Common Causes• Automobile accidents• Assaults• Falls• Work-related accidents• Sports-related accidents.
Common Symptoms• Loss of consciousness
• Dilated pupils
• Respiratory issues
• Convulsions
• Headache
• Dizziness
• Nausea and vomiting
• Cerebrospinal fluid leaking from nose or ears
• Speech and language problems
• Vision issues
• Emotional and behavioral changeswww.brainandspinalcord.org
Mortality Rates
• Severe Head injury = 30-50 %
• Most survivors exist in a vegetative state
• Moderate Head Injuries = 10-100%
• Permanent Disability and/or severe neurological effects
CT scan of left frontal acute epidural hematoma (black arrow) with midline shift (white arrow). Note the left posterior falx subdural hematoma and left frontoparietal cortical contusion.
Financial Burden
• Estimated to cost between 75 and 100 billion dollars annually.
• Why so costly?
• Closed-head injuries result in physiological, psychological, and psychosocial deficits that require extensive long-term rehab and care.
Emedicine.medscape.com
Concussions
• defined as an altered mental state that may or may not include loss of consciousness that occurs as a result of head trauma.
• Repetitive concussions may result in chronic subclinical motor dysfunctions linked to intracortical inhibitory system abnormalities.
Table 1.
American Academy of Neurology Concussion Grading Scale
Grade 1 Grade 2 Grade 3
Transient confusion
Transient confusion
…
No loss of consciousness
No loss of consciousness
Brief or prolonged loss of consciousness
Concussion symptoms or mental status change resolves in 15 min or less
Concussion symptoms or mental status change resolves
in more than 15 minutes
…
Concussions
• Sport-related concussions are frequent, with 300,000 cases reported each year.
• Football players and boxers are particularly exposed to repetitive concussions, leading to the condition now known as chronic traumatic encephalopathy syndrome.
Cerebral Contusions
• What are they?• caused by direct transmission of impact
energy through the skull into the underlying brain and occur directly below the site of injury.
• Occur with skull fractures on the frontal and temporal lobes of the brain.
• Can expand over time – usually 24 hours to 7-10 days after the initial injury.
Contrecoup injuries
• Are caused by rotational shear and other indirect forces that occur contralateral to the primary injury.
• Rotational force causes the basal frontal and temporal cortices to impact or sweep across rigid aspects of the skull, the sphenoid wing, and petrous ridges.
• Delayed enlargement of traumatic intraparenchymal contusions and hematomas is the most common cause
of clinical deterioration and death.
Epidural hematoma
• Epidural hematomas most commonly (85%) result from bleeding in the middle meningeal artery.
• Occur in 1% of all cases.• Epidural hematomas are
often associated with a "lucid interval," a period of consciousness between states of unconsciousness.
Subdural hematoma
• A surface or bridging vessel (venous) can be torn because the brain parenchyma moves during violent head motion.
• The resulting bleeding causes a hematoma to form in the potential space between the dural and arachnoid.
• A lucid interval is less likely to develop in this type of injury than in epidural hematomas.
Intraventricular hemorrhage
• Intraventricular blood is an indicator of more severe head trauma.
• Intraventricular blood also predisposes the patient to posttraumatic hydrocephalus and intracranial hypertension, which may warrant placement of an intraventricular catheter (if emergent drainage needed) or ventriculoperitoneal shunt for chronic hydrocephalus.
Secondary Injuries and Systemic Insults
Secondary Injuries• Hemorrhage
• Ischemia (low O2)
• Edema• Raised intracranial
pressure (ICP)• Vasospasm• Infection• Epilepsy• Hydrocephalus
Secondary Systemic Insults
• Hypoxia• Hypercapnia• Hyperglycemia• Hypotension• Severe hypocapnia• Fever• Anemia• Hyponatremia
How is Learning Effected?
• Frontal and Temporal Regions greatly effected.
• Reasoning, critical-thinking & problem-solving skills can be altered.
• Speech, language abilities, short-term memory can also be effected.
• High variety of mental skills can be altered depending upon the severity of the contusion.
Effects of Pressure on Blood Vessels
• Vessels rupture, blood pools
• Effects of blood chemicals on Nervous Tissue? (Platelets, dissolved ions, immune cells, etc)
• Nervous Tissue no longer fed, oxygenated in the affected area.
Current Research
• Blast Force that Causes Concussions in Soldiers
• Hypothesis: Pulse hits chest, travels up neck to brain (Johns Hopkins University)
• Hypothesis: Force to the head Causes
VasoSpasms
What is cerebral vasospasm?
• "Cerebral vasospasm" is a term that refers to physical narrowing of the central "lumen" of a brain blood vessel due to overcontraction of the vessel wall.
• "spasm" refers to the vessel's "spastic" or "shut down" or "constricted" physical state.
Vasospasm
Dr. Alford’s Work…
• Apply a specific force to a blood vessel invetro and…
• (a) Vasospasm ---> Hypercontracts to
1. Acute Symptoms
(I don’t feel well, etc.) OR
2. Vessels re-models, contracts again
and becomes smaller
(b) Can lead to vessel eruption or blockage
Dr. Alford
• When applied to neurons, it just massively disrupts them… they stop working.
• A 2nd force does not have to be as strong to trigger a vasospasm if remodeling does not occur.
• Dr. Alford’s Question:
What causes remodeling?