Neurological + Defib Review Flashcards
What do central chemoreceptors respond to?
Changes in O2 and CO2 in arterial circulation and CSF
What will decreased CO2 levels cause?
Hypoventilation > cerebral vasoconstriction > cerebral ischemia (lack of blood supply)
What will increased CO2 levels cause?
Hyperventilation > vasodilation > edema (hypoxia)
Regular levels for ICP?
5-15 mmHg
What is Cerebral Perfusion Pressure (CPP)?
Pressure needed to maintain blood flow to the brain.
- Regularly 70-80 mmHg
- Less than 60 DOUBLES death
What is Mean Arterial Pressure?
Average pressure in a person’s arteries in one cardiac cycle
- Regularly 70 - 100 mmHg
S&S of ICP?
- Severe headache (stretching of dural layer)
- Vomiting (projectile vomit due to pressure in emetic center of medulla)
- Papilledema (swelling of optic disc due to ICP)
- Seizures
Pathophysiology behind ICP?
- CSF will shift to spinal cavity to compensate
- This decreases cerebral blood flow
- Hypoxia eventually ensues
- Hypoxia will then trigger arterial vasodilation in the brain
- Adding fluid volume in an attempt to improve blood supply increases ICP
What is Cerebral Herniation Syndrome?
- Brain swelling which then forces tissues through the foramen magnum
- Obstructs blood flow
- Puts pressure on brain steam
S&S of Cerebral Herniation Syndrome?
- Decreased LOC
- Coma
- Dilation of pupil on same side
- Paralysis on opposite side of the body
- Decerebrate posturing
- Increased BP
- Bradycardia
What do you do to treat Cerebral Herniation Syndrome?
- Rapid transport
- Hyperventilate to reduce swelling at 1:3
What type of injury is highly vascular, bleeds well, and has inhibition of vasospasms?
Scalp wounds
How do you treat scalp wounds?
Direct pressure if no skull injuries
What does the Olfactory Nerve (CN 1) do?
Enables sense of smell; shortest sensory nerve
What does the Optic Nerve (CN 2) do?
Relays messages from the eyes to the brain to create visual images
What does the Oculomotor Nerve (CN 3) do?
Enables eye movements, such as focusing on an object that’s in motion
What does the Trochlear Nerve (CN 4) do?
Enables movement in the eye’s superior oblique muscle. This makes it possible to look down.
What does the Trigeminal Nerve (CN 5) do?
Sends pain, touch, and temperature sensations from the face to the brain.
What does the Abducens Nerve (CN 6) do?
Innervates the ipsilateral lateral rectus muscle.
Also partially innervates the contralateral medial rectus muscle
What does the Facial Nerve (CN 7) do?
Controls facial movement and expression.
Also carries nerves that are involved in taste and producing tears
What does the Vestibulocochlear Nerve (CN 8) do?
The vestibular nerve handles balance and equilibrium
The cochlear nerve handles hearing
What does the Glossopharyngeal Nerve (CN 9) do?
Provides motor, parasympathetic, and sensory information to the mouth and throat.
Specifically innervates the stylopharyngeus muscle (responsible for elevating pharynx and larynx)
What does the Vagus Nerve (CN 10) do?
Controls digestion, heart rate, and immune system.
What does the Spinal Accessory Nerve (CN 11) do?
Controls the movement of certain neck muscles
Innervates trapezius and sternocleidomastoid
What does the Hypoglossal Nerve (CN 12) do?
Enables tongue movement.
Innervates muscles that helps speak, swallow, and move substances in the mouth.
What are Tonic-Clonic (Grand Mal) seizures?
Two stages: tonic phase and clonic phase
Preceded by an AURA
Tonic phase - “Stiffening”. Loss of consciousness, possible fall. Spasm/stiffening of muscles can impair breathing.
Clonic phase - “Jerking”. Intense and rapid movement of arms, legs, and face. Usually lasts 1-3 minutes.
What are Petit Mal (Absence) seizures?
- Type of epilepsy
- Blanking out or staring into space for a few seconds
- Most common in children
- Lasts less than 15 seconds
What is a Transient Ischemic Attack (TIA)?
- Temporary symptoms similar to a stroke
- Lasts only a few minutes and doesn’t cause permanent damage
- Serves as a warning for future strokes
Focal Cerebral Dysfunction: Temporary reduction in blood flow
Can also be from spasm of arteries
What is the underlying cause of TIA’s?
Atherosclerosis (buildup of plaque) in an artery or one of its branches that supplies oxygen and nutrients to the brain.
Risk factors for TIA?
- Family history
- Age (after age 55, risk increases)
- Sex (Men have a slightly higher risk of TIA)
- Prior TIA’s
- Sickle cell disease
What is an Ischemic Stroke?
Occurs in two ways.
1) Blocked artery. Occurs when a blood clot blocks the blood flow in an artery within the brain.
2) Ruptured artery. Can lead to hemorrhagic strokes when a blood vessel bursts within the brain.
What is an Aneurysm?
Occurs when a part of an artery wall weakens, allowing it to abnormally balloon out or widen.
- If it bursts, it can lead to internal bleeding and often leading to death.
- High BP overtime can weaken vessels
S&S of Brain Aneurysm?
- Severe headache (worst headache of life)
- Stiff neck
- Nausea and vomiting
- Sensitivity to light
What is Diffuse Axonal Injury?
- Severe blunt head trauma
- Brain moves back and forth, resulting in STRETCHING, SHEARING, TEARING of nerve fibers
- Subarachnoid bleeding with irritation to surrounding tissues
- Often results in permanent vegetative state
What S&S would make you think someone has a Basilar Fracture?
- Leaking of CSF from nose and ears
- Periorbital ecchymosis
- Battle Signs (Mastoid Bruising - behind the ears)
What is an Anoxic Brain Injury?
- Lack of oxygen to the cells (from circumstances such as cardiac arrest, airway obstruction, drowning)
- Spasm of cerebral arteries affects perfusion
- After 4-6 minutes of anoxia? Irreversible damage
- Restoring blood pressure and oxygen will NOT restore perfusion
What is a Contrecoup Injury?
Rebounding on the skull, causing brain to impact the opposite side of the skull
- Closed Head Injury (skull is not fractured in the injury)
- Brain tissue is injured from force exerting it against the skull
- Blood vessels may rupture due to the force
Neurogenic Shock S&S?
- Bradycardic response to BP
- Skin is warm and dry
- No significant blood loss
- Paralysis and loss of spinal reflexes
Six General Causes of Coma?
Metabolic
Respiratory System
Drugs
Infection
Cardiovascular System
Structural
What is Kernig’s Sign?
Resistance to leg extension when hip is flexed 90 degrees
What is Brudzinski’s Sign?
Passive flexion of neck causes flexion of both legs/thighs
Regarding the Head Injury BLS Standard, what are your hyperventilation values for an Adult, Child, and Infant?
Adult - 20 breaths per min
Child - 25 breaths per min
Infant (<1 yr old) - 30 breaths per min
Thrombus vs Embolus?
Thrombus - Blood Clot
Embolus - Obstruction of blood flow due to mass of undissolved matter (i.e air embolus)
Where is Broca’s Area located?
Frontal Lobe
Where is Wernicke’s Area located?
Temporal/Parietal Lobe
What is the Blood Brain Barrier?
Tight seal of endothelial cells that lines the blood vessels in the brain.
- Semi-permeable (allows some materials such as O2, CO2, water, and general anesthetics to pass through
- Blocks toxins and bacteria
What is the Corpus Callosum?
White matter tracts that connect the left and right cerebral hemispheres.
What is the Frontal Lobe responsible for?
- Motor function
- Emotions
- Problem solving
Damage to Frontal Lobe results to loss of concentration, lack of judgment, decreased intellectual ability
What is the Parietal Lobe responsible for?
- Perception and sensory information
- Space navigation
- Language processing
What is the Temporal Lobe responsible for?
- Auditory processing
- Memory storage
What is the Occipital Lobe responsible for?
- Visual perception (i.e colour and motion)
Damage to the Occipital Lobe can cause vision impairments such as blindness, visual distortions
- Autoimmune disease
- Destruction of myelin in the brain and spinal cord
- Progressive disease of CNS
- Nerve and fibre damage
Upon hearing this, what disease do you think of?
Multiple Sclerosis
What is Dystonia?
A disorder where involuntary muscle contractions cause slow repetitive moments or abnormal postures.
- Associated with Parkinson’s and strokes
What is Parkinson’s Disease?
- Degeneration or damage to nerve cells in basal ganglia (voluntary motor movements)
- Lack of dopamine (affects nerve pathways that control muscle contraction)
- Tense muscles, tremors, joint rigidity
