MW Flashcards
Patho, neuro
Focal or diffuse injury to what specific region of the brain will result in a loss of consciousness or coma?
Diffuse injuries ( concussion or DIA) will typically cause an overall decreased level of consciousness. Whereas, focal injuries (such as an ICH or a contusion) will have symptoms based on the brain area affected
Define and compare focal and diffuse traumatic brain injury. What is the underlying structural and functional damage associated with diffuse brain injury?
The long connecting fibers in the brain called axons are sheared as the brain rapidly accelerates and decelerates inside the hard bone of the skull. DAI typically causes injury to many part of the brain, and people who suffer a DAI are usually left in a coma. The changes in the brain are often very tiny and can be difficult to detect using CT or MRI scans.
It is one of the most common types of traumatic brain injury and also one of the most devastating.
Kernig: what is it and how do you test for it?
A sign indicating the presence of meningitis (inflammation of the meninges covering the brain and spinal cord).
The test is done by having the person lie flat on the back, flex the thigh so that it is at a right angle to the trunk, and completely extend the leg at the knee joint.
Brudzinski’s sign:
is one of the physically demonstrable symptoms of meningitis. Severe neck stiffness causes a patient’s hips and knees to flex when the neck is flexed.
How to test for Brudzinski?
Supine patient. Place one hand behind pt’s head, and another on their chest to prevent from rising. Then, lift patient’s head, bringing their chin to chest=involuntary flexing @ hip is a + sign
Parenchymal injury (TBI); skull fractures
all forms of TBI can involve both a primary (first injury) and secondary (brain swelling, release of intracellular ions/transmitters)
Focal brain injuries
Contusions, Lacerations
Diffuse Brain injury (diffuse axonal injury)
Concussion
Traumatic Vascular Injury
Hematomas:Epidural, Subdural, Subarachniod, and intraparenchymal
Mechanism of closed head injury
acceleration-head thrown forward while brain hits back of skull
deceleration-head thrown backwards while brain hits front of skull
Coup and contrecoup injuries
In head injury, a coup injury occurs under the site of impact with an object, and a contrecoup injury occurs on the side opposite the area that was hit. Coup and contrecoup injuries are associated with cerebral contusions, a type of traumatic brain injury in which the brain is bruised.
What type of injury causes Diffuse Brain Injury/Diffuse Axonal Injury?
Concussion
How many different grades of concussion?
Grade I and II - some disturbance in attention or memory but no loss of consciousness
Grade III - may involve brief loss of conscioussness (less than 5 minutes)
Grade IV – Classic Cerebral Concussion - an immediate loss in consciousness that lasts more than 5 minutes but less than 6 hours
What is considered a mild concussion?
Mild Concussion – temporary axonal disturbances
Grade I and II - some disturbance in attention or memory but no loss of consciousness
What might a grade III concussion involve?
Grade III - may involve brief loss of conscioussness (less than 5 minutes)
What is another name for Grade IV
Classic Cerebral Concussion - an immediate loss in consciousness that lasts more than 5 minutes but less than 6 hours
What does a Classic Cerebral Concussion involve?
Involves temporary disruption of the Reticular Activating System (RAS)
What is the RAS
The reticular activating system (RAS) is a network within the brainstem that plays a role in regulating the alertness, or arousal, of the brain and thus plays an important role in regulating wakefulness and sleep-wake transitions.
Acute Epidural Hematoma
occurs when a mass of blood forms in the space between the skull and the protective covering of the brain. … As it swells, the brain may shift in the skull. Pressure on and damage to the brain’s tissues can affect vision, speech, mobility, and consciousness.
Which artery is affected in an acute epidural hematoma?
The majority of bleeds originate from meningeal arteries, particularly in the temporal region. Middle meningeal artery-branches of middle meningeal artery
EDH or SEDH (spinal epidural hematoma)
An epidural hematoma (EDH) occurs when blood accumulates between the skull and the dura mater, the thick membrane covering the brain. They typically occur when a skull fracture tears an underlying blood vessel. EDHs are about half as common as a subdural hematomas and usually occur in young adults.
What does a Subdural Hematoma affect? (SDH)
Is a neurosurgical emergency!!! Is most often the result of a severe head injury. This type of hematoma is among the deadliest of all head injuries. The bleeding fills the brain area very rapidly, compressing brain tissue. This often results in brain injury and may lead to death.
Between what 2 membranes does a SDH occur?
A subdural hematoma (SDH) is a collection of blood below the inner layer of the dura but external to the brain and arachnoid membrane. Subdural hematoma is the most common type of traumatic intracranial mass lesion.
How are SDH characterized?
are usually characterized on the basis of their size and location and the amount of time elapsed since the inciting event age (ie, whether they are acute, subacute, or chronic)
What blood vessels are affected by SDH? Venous or arterial?
Typically, low-pressure venous bleeding from bridging veins dissects the arachnoid away from the dura, and the blood layers out along the cerebral convexity. Cerebral injury results from direct pressure, increased intracranial pressure (ICP), or associated intraparenchymal insults.Can be due to a ruptured small cortical artery but most often is due to rupture of bridging veins
Bridging veins that extend across to the superior aspect of the cerebral hemispheres are involved in what type of bleed?
SDH
What are the 4 types of CVAs?
Thrombotic Stroke
Embolic Stroke
Hemorrhagic Stroke
Lacunar Stroke
What is Global cerebral ischemia vs. Focal cerebral ischemia?
Lack of blood flow can affect the entire brain (global ischemia) or just a portion of it (focal ischemia). Ischemia can also be permanent, or transient if reperfusion occurs. This gives rise to a natural permutation of four general types of cerebral ischemia
What is the output hemisphere?
Motor cortex-left hemisphere section controls right side of body
What is the input area?
Sensory cortex-left hemisphere section receives input from body’s right side
What is the language circuit of the brain?
Wernicke’s Area:
Anglular Gyrus:
Broca’s Area:
What is processed @ Wernicke’s Area?
is the area auditory Input for language is processed– important for Understanding speech