Disorders of Brain Function Flashcards
How do brain injuries occur?
Ischemia Trauma Tumors Degenerative processes Metabolic Derangements
Hypoxia and Ischemic Injury
Hypoxia
- low O2
- interferes with delivery of oxygen to the brain
- Ischemia
Low Blood Flow (think systematic)
- interferes with delivery of oxygen and glucose along with removal of waste products
- ex: hypovolemic shock, profusion issue
What causes Hypoxia and Ischemic Injury?
Strokes, Hypovolemic Shock, any profusion issue
What factors are involved with Increased Intracranial Pressure (ICP)
the amount of blood, brain tissue and CSF
What is the normal intracranial pressure?
0-15 mmHg while supine
Herniation
Displacement of brain tissue through skull
What is the brain protected by?
non-expandable skull and supporting septa
What do we do when there is ICP?
either drill a hole in the skull to drain the blood or if it is a CSF issue we can put a shunt in
What compensatory mechanisms does the brain have to control intracranial pressure?
Mainly controlling how much cerebrospinal fluid is pushed in and out of the brain cavity, also it can adjust Blood Pressure but this doesn’t affect the pressure nearly as much as controlling the CSF
What can cause ICP?
tumor, problems with vasculature (hemorrhagic stroke), hematoma, increased CSF, swelling from injury
What is Hydrocephalus?
abnormal increase in CSF volume in any part or all of the ventricular space
treatment: ventriculoperitoneal Shunt placement (so CSF can get out of the ventricular space)
What is a TBI?
traumatic brain injury
-structural damage to the brain and skull
could be an open head injury or closed
What is the leading cause of death of people under the age of 24?
TBI
What is the leading contributing factor/cause of TBIs?
lack of helmets and seatbelts
What are the 4 main types of Skull fractures (list)? What are the other types?
Simple (closed: skin is not broken)
Compound (open: skin is broken, laceration)
Depressed (like a cracked hard boiled egg)
Basilar
other types: linear, greenstick (incomplete fracture), comminuted (broken into 3 pieces or more)
Coup-Contrecoup
contusion resulting from a strong blow to the head, causing the brain to slam against the inside of the skull
Coup (primary)- injury of the brain where a direct hit has occurred
Contrecoup (secondary)- results when the brain impacts the side of the skull opposite the point of impact
- diffuse axonal injury
- widespread brain effects
- permanent brain injury
- coma/vegetative
Concussion
-recovery w/in 24 hours with mild concussions
S/S : headache, irritability
-s/s may persist for months (post concussion syndrome)
What is Post Concussion Syndrome?
where symptoms of the concussion can last days/weeks/months
-headaches, memory lapses
Traumatic Intracerebral Hematomas
- can occur in any lobe of the brain
- may be single or multiple
- occur most often in alcoholics and elderly (they fall a lot)
Vascular Deformity (AVM - arteriovenous malformation)
some vascular malformations lie deep in the brain and can cause hemorrhage directly into brain tissue
abnormal connection of the arteries and veins, by passing the capillary beds
-no exchange of gases…no capillary beds
-congenital
How can you know if you have a Vascular Deformity?
you wont know until you have a CT scan and it is found or it ruptures
Epidural Cerebral Hematoma
bleeding is rapid because of Skull Fracture and severance (ruptured) of Meningeal Artery
(bleeding between bone of skull and dura)
Subdural Cerebral Hematoma
bleeding is slow and results from tearing of veins that extend across the subdural (subarachnoid) space
- bleeding b/w dura and arachnoid space
- tearing of the small bridging veins
Acute Cerebral Hematoma
lasts 48 hours
s/s: could range from headache, ipsilateral SP?? (one sided) pupil that is fixed and dilated, confusion
Subacute Cerebral Hematoma
2-14 days
get better and then decline
S/S can be chronic
can have continual tears
seen in alcoholic and elderly (harder to diagnose in elderly)
What is a Cerebral Vascular Accident?
a stroke (requires rapid emergency treatment)
What are the major risk factors for CVA (stroke)?
Age, Gender (male), African American Heart disease, HTN high cholesterol Cigarette smoking prior stroke, diabetes Atrial Fibrillation (A-fib patients are high risk for throwing clots)
What are the two types of Stroke?
Ischemic and Hemorrhagic
What is a Ischemic stroke?
- interruption of blood flow in a cerebral vessel
- bloodless infarct of brain tissue caused by arterial Ischemia due to atherosclerotic blood vessels supplying the brain
What is a Hemorrhagic stroke?
- bleeding into brain tissue, associated with a much higher fatality rate than ischemic strokes
- usually caused by uncontrolled HTN
What are Ischemic strokes caused by ?
thrombosis or emboli
What is a TIA?
Trans-Ischemic Attack
“mini-stroke” “mini brain attack”
symptoms last 24 hours or less
What is a Large Vessel Stroke?
stroke caused by thrombus in large vessel of brain
What is Small Vessel Stroke?
stroke caused by thrombus in small, deep vessels
What is a Cardiogenic Embolic Stroke?
blood clot moves to brain from another area (carotid artery)
What should we be mindful of when treating a patient who is suffering from an Hemorrhagic Stroke?
(Bleeding into the brain)
wouldn’t want to give anticoagulants to these patients because it thins blood and could cause even more damage
What kind of stroke is most frequently fatal?
hemorrhagic stroke
What are the risk factors for hemorrhagic stroke?
advancing age, HTN, Aneurysm, Trauma, Drugs, Erosion by tumors, blood coagulation disorders, results in edema, compression and/or spasm
What is an Aneurysmal Subarachnoid Hemorrhage?
Bleeding into the subarachnoid space
What usually causes an Aneurysmal Subarachnoid Hemorrhage?
a ruptured cerebral aneurysm
What are the risk factors for Aneurysmal Subarachnoid Hemorrhage?
smoking and HTN
average age is 50 years old
What portion of patients suffering from Aneurysmal Subarachnoid Hemorrhage recover without major disability?
1/3
How will a patient with an Aneurysmal Subarachnoid Hemorrhage present coming into the hospital?
Atypical Headache “Worst of my life”
What is Meningitis?
inflammation of the pia mater, the arachnoid and the CSF filled subarachnoid space
Why are brain infections harder to treat?
because the medication has to be able to penetrate the blood-brain barrier
What is Bacterial Meningitis caused by?
S. pneumoniae, H. influenzae or Neisseria meningitdis (<– yes that is spelled right according to our notes)
What should people do if they were exposed to Bacteria that causes Meningitis?
ATB therapy (antibiotic)
What most often causes Viral Meningitis?
enteroviruses
Which type of Meningitis is less severe?
Viral
Viral Meningitis
self limited and require only symptomatic treatment
Encephalitis
generalized infection of parenchyma of brain and spinal cord
Seizure Disorders
abnormal, uncontrolled discharge of impulses from the brain
When may a seizure occur?
almost all serious illness or injuries affecting the brain
-infections, tumors, drug abuse, vascular lesions, congenital deformities and injury
could be provoked or unprovoked.
What is an example of a provoked seizure?
seizure brought on by flashing lights
Simple Seizure
30-60 seconds, no loss of consciousness, sudden jerking, sensory phenomena, transient weakness or loss of sensation
Complex Seizure
1 to 2 minutes, may have aura, automatisms, unaware of environment, may wander, amnesia for seizure events, mild to moderate confusion during, sleepy afterwards
Secondarily Generalized Seizure
starts as a partial seizure.
it starts in one limited area of the brain. The forms they take vary as much as other partial seizures. But then the seizure spreads throughout the brain, becoming a “generalized” seizure
What are the types of partial Seizures?
Simple, Complex and Secondarily Generalized
What are the Epileptic Syndromes?
Generalized seizures Absence seizures Atonic Seizures Myoclonic Seizures Tonic-Clonic Seizures
Generalized Seizures
Primary generalized seizures
Absence seizures
brief impairment of consciousness (stare off and then come back)
Atonic Seizures
Abrupt loss of muscle tone - head drops, loss of posture, or sudden collapse (see the children with the helmets on)
Myoclonic Seizures
sudden, brief, involuntary muscle jerks
Tonic-Clonic Seizures
grand mal or a convulsion
What is Dementia?
intellectual deterioration
What disease is the cause of 50-70% of all cases of dementia?
Alzheimer’s Disease
Alzheimer’s Disease
the most common form of dementia
cortical atrophy, loss of neurons
insidious and progressive
How is Alzheimer’s officially diagnosed?
during an autopsy, but usually drs cant suspect Alzheimers through signs and symptoms before the person dies
What causes Alzheimer’s?
no known cause
Besides Alzheimer’s what are the other types of Dementia are there?
Vascular Dementia Pick Disease Creutzfeldt-Jakob Wernicke-Korsakoff Huntington's Disease
Vascular Dementia
-infarcts in the brain from bleed
Risk Factors: HTN, CVA, smoking
results in psychomotor deficits
Pick Disease
Form of dementia
RARE degernative neurological disorder
atrophy of frontal and temporal areas of the brain
Creutzfeldt-Jakob
form of Dementia
infective protein called a prion
Transmittable (can catch it)
Wernicke-Korsakoff
form of Dementia
results from chronic alcoholism
Huntington’s Disease
form of dementia
INHERITED autosomal dominant disorder
localized loss of brain cells
