Neuro Assessment & ICP Flashcards
Central Nervous System (CNS)
Comprised of the ___ and ___
brain; spinal cord
Peripheral Nervous System (PNS)
- Cranial nerves (12 pairs)
- Spinal nerves (31 pairs)
- Autonomic nervous system [involuntary]
> SNS & PNS - Somatic nervous system (voluntary)
- Enteric nervous system of the GI tract
?
Are impulse-controlling cells that facilitate communication within the nervous system
Receive stimuli & transmit or conduct info in response to the stimuli
3 types of
Neurons
?
Are specialized cells that support & protect the neurons
Are up to 10x more common; provide support, nutrition, & protection
Have the ability to multiply, & this makes them a common source for tumor growth in the brain & spinal cord
Neuroglial cells
Neuroglial cells
- Astrocytes
- Ependymal cells
- Microglia
- Oligodendrocytes
?
Are located entirely in the CNS
Integrate incoming & outgoing msgs, process & store info, & “make decisions” about the body’s response to the stimuli
Interneurons
___ neurons
Transmit msgs from the brain back to the muscles or glands that respond, & are considered motor nerves
Efferent
___ neurons
Detect sensory stimuli from receptors such as sensory nerve endings & transmit them to the CNS
Afferent
___ neurons
Detect sensory stimuli from receptors such as sensory nerve endings & transmit them to the CNS
Afferent
Structure of a Synapse/Neurotransmitters
- Acetylcholine
- Norepinephrine
- Dopamine
- Serotonin
- GABA (gamma-aminobutyric acid)
- Glutamate
Central Nervous System
- Cerebrum
- Cerebellum
- Medulla (brain stem)
?
Is the largest portion of the brain, covered by a thin layer of gray matter, the cerebral cortex
Cerebrum
The ___ ___ are located in the front area of the brain & are largely responsible for motor movement, mood, thoughts, & personality
frontal lobes
The Broca’s expressive speech area is within the frontal lobe
Located behind the frontal lobes, the ___ ___ control sensation & perception, such as temperature, taste, touch, & movement coming from the rest of the body; spatial relationships
parietal lobes
The ___ ___ are located on the sides of the brain level w/the ears, beneath the parietal lobes, & control sound recognition/hearing, and language/speech
The Wernicke’s receptive speech center is here
temporal lobes
The ___ ___, located at the back of the brain, is responsible for processing visual info
occipital lobes
These lobes are further divided into right and left hemispheres w/specific functions that are important when assessing neurological deficits
Most people are left hemisphere dominant, even in left-handed people
The brainstem is composed of the ___, ___, and ___
midbrain, pons, medulla
?
Is continuous w/the spinal cord & is located @ the level of & below the foramen magnum, the opening in the skull that allows the spinal cord to connect w/the brainstem
medulla oblongata
?
Rests above the medulla oblongata below & anterior to the midbrain, & relays all impulses between the brain & the spinal cord
Pons
?
Is located in the base of the brain or posterior fossa posterior to the medulla oblongata & pons
Cerebellum
?
Contains the nerve pathways between the cerebrum & the medulla oblongata
Midbrain
?
Runs through all lvls of the brainstem & conduction of the motor & sensory tracts is relayed through the brainstem to the cerebellum & the cerebrum
Consists of the networks of neural cells that have these functions:
* Motor control & coordination & maintaining balance & posture during movement
* Resp & cardiac control
* Pain modulation by providing a route of passage for pain signals from the lower body
* Alertness & sleep by controlling some of the sensory stimuli that reach the cerebral cortex
Reticular formation
?
Serves as relay center for sensory impulses to cerebral cortex
Thalamus
?
In coordination w/the cerebellum, regulates movement by sending info back and forth through the thalamus to the cerebral cortex
Signals from are inhibitory whereas cerebellum signals are excitatory
Basal ganglia
?
Is the main regulator for the ANS by sending signals to the brainstem, regulating among other things HR & BP
Hypothalamus
?
Consists of the cingulate gyrus, hippocampus, & amygdala
Referred to as the “emotional brain”
Limbic system
Blood from the deep internal & external veins, as well as CSF from the subarachnoid space, empty into these channels to be transported back to the heart via the internal jugular vein
Blood flow in the brain: arterial circulation
- Is supplied by the right & left internal carotid arteries & the right & left vertebral arteries
- The internal carotid arteries & the vertebrobasiliar arteries join together via the posterior communicating artery @ the base of the brain to form the circle of Willis
Venous blood flow
- Blood from the deep internal & external veins, as well as CSF from the subarachnoid space, empty into these channels to be transported back to the heart via the internal jugular vein
Spinal cord
- Made up of both gray matter & white matter
- Pathway carries info to and from the brain & the body
- Decussation (“crossover”)
- contralateral (opposite)
- ipsilateral (same)
- Controls body movement
- Regulates organ function
- Process sensory info from the extremities, trunk, & internal organs
- Transmits info to & from brain
Protective Mechanisms
- Cranium
- Vertebrae
- Meninges
- Consist of the meningeal layers & spaces
- Protect the brain & spinal cord
- Outer layer is the __ __, which is a tough fibrous membrane that rests against the interior part of the skull
dura mater
The 2nd layer of the meninges is the ___, which is a very thin layer w/a spiderweb appearance
The inner membrane is the ___ ___ which is the highly vascular membrane that lies in direct contact w/the brain
arachnoid
pia mater
The epidural space is the potential space that exists between the inner dura mater layer & the arachnoid layer
The third space is the ___ ___, which is between the arachnoid membrane & the pia mater
subarachnoid space
- The meningeal layers cover the spinal cord, but also fold into the brain
- One fold (falx cerebri) separates the right and left cerebral hemispheres
- Another layer (tentorium cerebelli) separates the cerebrum from the cerebellum
- CSF
> Provides cushioning, protection, & nutrition - Blood-brain barrier
Peripheral Nervous System: Spinal Cord
- 31 pairs of spinal nerves
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
Spinal nerves are mixed nerves as they transmit signals in both directions
Peripheral Nervous System
- Includes spinal nerves and cranial nerves
Autonomic (involuntary)
- sympathetic (“flight or fight”)
- parasympathetic (rest)
Somatic (voluntary)
- muscle movement
Enteric
- GI tract nervous system; controls the autonomous responses of the digestive process
Cranial Nerves
- Originate in the brain except for the olfactory & optic nerves
- Transmit signals to receptors in the body
- Identified by roman numerals
- Named in order according to where they arise in the brain
?
- Opposes SNS
- Decreases HR, RR, BP
- Constricts pupils
- Stimulates GI tract, GU system
Parasympathetic (or craniosacral)
?
- “fight-or-flight”
- Increases HR, RR, BP
- Dilates pupils
- Inhibits GI tract, GU system
Sympathetic (or thoracolumbar)
SNS
The neurotransmitter released @ the synapse site is typically ___, & the fibers that secrete it are adrenergic fibers
norepinephrine
PNS
The neurotransmitter released @ the synapse site is ___
The nerve fibers that secrete it are called cholinergic fibers
acetylcholine
Neuro Assessment
History
> Best provided by the pt
Physical assessment
> Levels of consciousness, cranial nerves, motor & sensory systems, cerebellar assessment & reflexes
Cognitive → Mini-Mental Status Exam; memory [remote (longterm), recall (recent), immediate (new)]
Motor/Cerebellar → Muscle mass, strength, tone, equality, balance, coordination, gait, posture
Cranial Nerve → Perform CN assessments; PERRLA, etc.
LOC → GCS
Sensory → Temp, pain, proprioception, cortical sensory
Reflexes → Reflex hammer: absent, weak, normal, stronger, hyperactive
Glasgow Coma Scale (GCS)
The higher the #, the better the patient’s LOC
States of Consciousness
- Alert
- Lethargic
- Obtunded
- Stuporous
- Comatose
The single most important assessment is evaluation of level of consciousness (LOC) and mentation
A change in either is usually the first clue to a deteriorating condition
Full consciousness
- The pt is alert, attentive, & follows commands. If asleep, she responds promptly to external stimulation &, once awake, remains attentive
Coma
- The pt does not respond
Lethargy
- The pt is drowsy but awakens - although not fully - to stimulation. She will answer questions & follow commands, but will do so slowly & inattentively
?
The pt arouses to vigorous & continuous stimulation; typically, a painful stimulus is req’d. She may moan briefly but does not follow commands. Her only response may be an attempt to withdraw from or remove the painful stimulus
Stupor
?
The pt is difficult to arouse & needs constant stimulation in order to follow a simple command. She may respond verbally w/1 or 2 words, but will drift back to sleep between stimulation
Obtundation
? posturing
Usually assoc w/brainstem dysfunction
Decerebrate
? posturing
Results from damage to one or both corticospinal tracts
Decorticate
VS & Increased Intracranial Pressure
Regulated in the brain & brainstem
- HR
- BP
- Respirations
These VS changes are usually LATE SIGNS of increased ICP or neurological deterioration
Normal ICP is ___-___
7-15
Measurements greater than __-__ indicate increased ICP and require intervention
Sometimes pts w/IICP will demonstrate sx’s of changes in LOC, vomiting, headaches, & seizures
The CLASSIC signs of IICP are known as ____, which is characterized by an ____, ____, and ____
15-20
Cushing’s Triad
elevated BP w/a widening PP, bradycardia, irregular respirations
Considerations for the Older Adult
- Slowed body movements
- Dec reaction time
- Dec muscle strength & flexibility
- Dec sense of touch, smell, temp, & pain sensations
- Possible cognitive impairment such as confusion and/or memory loss - use caution to eval for other causes of cognitive issues such as infection
Diagnostic Testing
- Radiographic procedures
- CT, PET, MRI
- Cerebral angiography (! shellfish/iodine allergy)
- CT angiography
- EEG
- Evoked potential
- LP
- Myelography/myelogram
- Brain biopsies
LP
- Insertion of spinal needle into the subarachnoid space (between the 3rd/4th or 4th/5th lumbar vertebrae)
- Contraindicated in pts w/IICP
- Position - fetal side-lyng, then FLAT after
- Spinal HA possible from spinal tap
- COMPLICATIONS -
Brainstem herniation, infection, CSF leakage, & hematoma formation
