4 - Neuro Disorders Flashcards
When are the maximal effects of primary brain injuries seen?
18-36 hours
What is the source of bleeding in 85% of epidural hematomas?
Arterial
Almost always a medical emergency
Briefly regain consciousness, then unconscious again
Where does epidural bleeding occur?
between the dura and the skull
where does subdural bleeding occur?
between the dura and the brain
Tears in what veins cause subacute subdural hematomas?
Bridging veins
Subdural hematomas are more common in what population?
Why?
older adults and alcoholics
some degree of brain atropy cause increased size of epidural space and more stress on the bridge veins
What are the GCS levels for TBI:
Mild
Moderate
Severe
13-15
8-13
<8
What is second brain injury?
hypotension, hyperglycemia, anemia, cerebral edema
anything that happens as a result of the brain injury
What is chronic traumatic encephalopathy?
progressive dementia r/t repeated brain injury
boxers, soldiers, etc.
What is primary and secondary spinal cord injury?
primary: the injury from initial trauma/destruction
secondary: cascade of vascular, cellular, and biochemical events (edema etc)
Where do vertebral injuries most often occur in adults?
Most mobile portions of the column:
C1-C2
C4-C7
T10-L2
What causes spinal shock?
Loss of continuous tonic discharge from the brain or brainstem
What is neurogenic shock?
occurs with cervical or upper thoracic cord injury
may exist with spinal shock
sympathetic nerves pass through the spine and are therefore cut off, but parasympathetic activity passes through the vagus and remains intact
get a massive wave of uninhibited parasympathetic activity
With acceleration injuries the greatest stress point is:
C4-C5
With deceleration injuries the greatest stress point is:
C5-C6
complete quadriplegia results in injury at:
partial quadriplegia:
above C6
at or below C6
What is autonomic hyperreflexia?
sudden, life-threatening massive reflex sympathetic discharge
associated with spinal cord injury at T6 or above where descending inhibition is blocked
what is the most common cause of autonomic hyperreflexia?
distended bladder or rectum
but can be any sensory stimulation that’s unpleasant
What is the cause of most lower back pain?
Usually idiopathic and non-specific
What is spondylolysis?
What is spondylolisthesis?
fracture of the pars interarticularis (where the vertebral body meets the posterior structures)
displacement of the pars interarticularis (slides forward)
Degenerative Disk Disease pain is caused by:
protrusion of the disk
OR
narrowing of the spinal canal/intervertebral foramen by osteophytes
what is radiculopathy?
compression or inflammation of a spinal nerve root causing dermatomal distribution of pain
Where do disk herniatons almost never occur?
thoracic
What are symptoms of cauda equina syndrome?
saddle anesthesia
decreased or absent reflexes in the lower extremities
neurogenic bowel or bladder dysfunction
When does a herniated disk merit surgery?
severe compression
cauda equina syndrome requires emergency surgical evaluation
What is the difference between embolic and thrombotic strokes?
Thrombotic strokes are caused by clots that originate in the cerebral vessels
Embolic strokes are caused by clots that migrate from outside the brain (usually the heart, aorta, or common carotid)
What are lacunar strokes?
small vessel disease caused by perivascular edema, thickening and inflammation of the arterial wall
Usually in the basal ganglia, pons
what is a hemodynamic stroke?
brain hypoperfusion d/t inadequate blood delivery
what is the ischemic penumbra?
zone of borderline ischemic tissue that isn’t permanently damaged
Window of opportunity for protecting the penumbra is 3 hours
________ is associated with ruptured aneurysms, AVMs, cavernous angioma, or brain trauma
________ is usally just associated with brain trauma
SAH
SDH
What is an AVM?
mass of dilated vessels between the arterial and venous systems
Its an AV fistula in the brain
What causes AVMs?
persistent embryonic patterns of blood vessels
What percentage of AVMs lead to seizures?
50%
The other 50% experience a hemorrhagic stroke
Which type of head bleeds often reoccur?
SAH
especially if it’s due to a ruptured intracranial aneurysm
What is the mortality from an SAH?
50%
40-60% of patients with SAH also experience:
Delayed cerebral ischemia (DCI)
Inflammatory substances from the SAH damage cause cerebral artery vasospasms in adjacent (or nonadjacent) vessels
Can prolong cell death in the area up to 3-14 days
What is the diagnostic marker of a migraine?
Lasts 4-72 hours
What neurosubstances are associated with migraine?
Elevated CGRP
Increased glutamate
Decreased serotonin
What are the most common pathogens to cause bacterial meningitis?
meningococcus
pneumococcus
How is bacterial meningitis spread?
respiratory droplets and contact with contaminated saliva
can be a carrier without exhibiting symptoms
Which is worse: bacterial or viral meningitis?
Which has a vaccine?
Bacterial
Bacterial
Guillain Barre is a demyelinating disease of the _____
MS is a demyelinating disease of the _____
PNS
CNS
In MS, what is a clinically isolated syndrome?
a demyelinating event that manifests as an acute neurologic episode
What happens with botulism poisoning?
inhibited release of Acetylcholine leads to severe flaccid paralysis and death
What is myasthenic crisis?
severe muscle weakness with depressed respiratory function
danger of respiratory arrest
What is a cholinergic crisis?
often caused by anticholinergic drug toxicity
Massive amounts of acetylcholine at the NMJ
Increased intestinal motility, bradycardia, pupillary constriction, increased salivation, diaphoresis
looks like a myasthenic crisis but occurs 30-60 min after taking an anticholinergic med
What is the most lethal and common type of primary brain tumor?
Glioblastoma Multiforme (GBM)
Grade IV astrocytoma
Which is more common: secondary or primary brain cancers?
10x more likely to be from metastasis
Describe the anterior and posterior fontanel in infants
anterior is diamond shaped and closes at 18 months
posterior is triangular shaped and closes at 2-3 months
What usually causes hemorrhagic strokes in children?
congential cerebral AVMs
What is moyamoya disease?
chronic, progressive stenosis of anterior circulation (internal carotids or middle cerebral aa)
Looks like a “puff of smoke” on CTA
