Awake or Alert
-controlled by projections from reticulum of brain stem to cerebrum
Cognition
-controlled by cerebral cortex
Reticular Activating System (RAS)
-filter of information that regulates emotional and behavioral responses to sensory information
-damage hear will impair consciousness
Glasgow Coma Scale
-a clinical scale used to reliably measure a person's level of consciousness after a brain injury
-assesses a person based on their ability to perform eye movements, speak, and move their body.
ischemia, excitotoxicity, cerebral edema, increased intracranial pressure
What are the common mechanisms underlying brain damage with injury?
Ischemia
-reduced blood flow=less ATP and less O2
-occurs with stroke, myocardial infarction
Excitotoxicity
-over saturation of excitatory amino acids such as glutamate and over-excite neurons to death
NMDA recpetors
-ligand-gated ion channels that allow calcium influx following glutamate stimulation
Calcium
________ imbalance stresses neurons
Neurodegenerative
Excitotoxicity is the hallmark of what type of diseases?
Cerebral edema
increase in water & sodium content
Cytotoxic edema
swelling of cells with fluid
Vasogenic edema
swelling of interstitial space with fluid
Increased intracranial pressure
-changes in amount of blood (10% of space), brain tissue (80% of space), and CSF (10% of space) leads to obstructed blood flow, neuron death, and displaced tissue
Concussion
-mild traumatic brain injury
-brought on by rotational forces, acceleration, deceleration
- symptoms: dizziness, nausea, headache, confusion, slurred speech, appearing dazed, fatigued, amnesia
-treatment: none; recover w rest
CTE (chronic traumatic encephalopathy)
Repeated concussions can lead to what?
Ischemic
occlusion (blockage or closing) of a blood vessel, typically a clot
Thrombotic stroke
Most common ischemic stroke; often occurs in large vessels
Small vessel stroke
-also called lacunar; because they leave behind small cavities
- hypertension and diabetes are leading causes
Hemorrhagic
rupture of a cerebral blood vessel; bleeding occurs inside or around brain itssue; most fatal
signs of a stroke
loss of balance, vision disturbance, facial drooping, arm weakness, speech difficulty, time to call 911
stroke penumbra
-region of tissue radiating out from stroke
-damage continues over time
-accounts for deterioration in function after stroke
hemorrhagic
What is the most fatal type of stroke?
thrombolytics; tPA; intracranial stent
What medication/methods do we use to treat ischemic strokes?
Aneurysm
-ballooning of an artery
aneurysmal hemorrhage
-rupture of the aneurysm
intracerebral hemorrhage
What condition leads to a focal hematoma?
Nimodipine (calcium channel blocker)
What medication can we use to treat brain hemorrhages?
lysis of bacteria leads to the release of endotoxins that initiate inflammation
How does bacterial meningitis occur?
primary cns lymphoma
which type of brain cancer is increasing in prevalence?
too much excitatory transmission or too little inhibitory transmission
What causes seizures?