Chapter 43: Assessmet of the Nervous System

Question 0

Peripheral nervous system

Answer 0

Includes 12 pairs of cranial nerves, 31 pairs of spinal nerves, and the autonomic nervous system which is divided into sympathetic and parasympathetic

Question 1

CNS

Answer 1

Includes the brain and spinal cord

Question 2

Largest lumbar cistern

Answer 2

site of lumbar puncture, between L2 and S2, Contains a large amount of CSF

Question 3

Neurons

Answer 3

ØThe basic unit of the nervous system. Transmits impulses, or “messages”
•Motor neurons cause movement or mobility
•Sensory neurons cause sensory
•Some neurons process information, and some retain information
•When a neuron receives an impulse from another neuron, the effect may be excitation or inhibition.

Question 4

Mechanism for nerve impulse conduction

Answer 4

ØEach neuron has a cell body, or soma; short, branching process called end dendrites; and a single axon (Fig. 43-1).
ØEach dendrite synapses with another cell body, axon, or dendrite and brings information to the cell body from other neurons by an afferent pathway.
ØAn efferent pathway sends messages from the neuron’s cell body to other neurons through an axon.

Question 5

Myelin sheath

Answer 5

˜Myelin sheath covers many axons
ØWhen the myelin sheath is impaired, the impulses cannot travel from the brain to the rest of the body such as multiple sclerosis.

Question 6

Neurons produce substances

Answer 6

˜Each neuron produces a specific neurotransmitter substance or chemical such as acetylcholine or serotonin that either enhances or inhibits the impulse but cannot do both.

Question 7

Stimulus is effected by

Answer 7

˜The strength of the stimulus can be influenced by inhibition by another neuron, inadequate supply of transmitter substance, and extracellular fluid changes.
˜Lack of oxygen or the effects of hypnotics and anesthetics can quickly depress nerve activity. An example, in older adults, lack of oxygen to the brain often causes changes in mental state.
˜Changes in the pH of ECF also affect neuron transmission. For example, acidosis depresses nerve activity, alkalosis excites nerve activity
˜Increases nerve activity with some drugs such as caffeine, theophylline (tea and some asthma drugs) and theobromine (in cocoa)

Question 8

Neuroglial cells

Answer 8

˜Neuroglial cells provide protection, structure, and nutrition to neuron; are part of the blood brain barrier (BBB) and help regulate cerebrospinal fluid (CSF)

Question 9

BBB. Blood brain barrier

Answer 9

˜The BBB keeps some substances in the bloodstream out of the cerebrospinal circulation and out of brain tissue.
ØSubstances that can pass through the BBB include oxygen, glucose, Co2, alcohol, anesthetics, and water.
ØLarge molecules such as albumin, any substance bound to albumin, and many antibiotics are prevented from crossing the barrier.

Question 10

BBB

Answer 10

˜The BBB keeps some substances in the bloodstream out of the cerebrospinal circulation and out of brain tissue.
ØSubstances that can pass through the BBB include oxygen, glucose, Co2, alcohol, anesthetics, and water.
ØLarge molecules such as albumin, any substance bound to albumin, and many antibiotics are prevented from crossing the barrier.

Question 11

CNS

Answer 11

ØComposed of the brain which directs the regulation and function of the nervous system and all other systems of the body
ØComposed of the spinal cord, which starts reflex activity and transmits impulses to and from the brain

Question 12

Meninges

Answer 12

The brain and spinal cord have a protective covering called the meninges

Question 13

Subarachnoid space

Answer 13

˜The subarachnoid space is where the CSF circulates.

Question 14

Epidural space

Answer 14

A potential space, referred to as the epidural space, is located between the skull and the outer layer of the dura, this area extends down the spinal cord and is important in the delivery of epidural analgesia and anesthesia.

Question 15

Right brain/left brain

Answer 15

ØThe right and left hemispheres of the brain are joined by a bundle of fibers called the corpus callosum that delivers messages from one side to the other. Each hemisphere controls the opposite side of the body. If a brain tumor or cerebral stroke is located on the right side of the brain, your left arm or leg may be weak or paralyzed.

Question 16

Left hemisphere

Answer 16

the left hemisphere controls speech, comprehension, arithmetic, and writing.

The left hemisphere is dominant in hand use and language in about 92% of people.

Question 17

Right hemisphere

Answer 17

The right hemisphere controls creativity, spatial ability, artistic, and musical skills

Question 18

Frontal lobe

Answer 18

˜Frontal lobe
˜Personality, behavior, emotions, Judgment, planning, problem solving, Speech: speaking and writing (Broca’s area), Body movement (motor strip) Intelligence, concentration, self awareness

Question 19

Parietal lobe

Answer 19

˜Parietal lobe
˜Interprets language, words
˜Sense of touch, pain, temperature (sensory strip)
˜Interprets signals from vision, hearing, motor, sensory and memory
˜Spatial and visual perception

Question 20

Occipital lobe

Answer 20

˜Occipital lobe

ØInterprets vision (color, light, movement)

Question 21

Temporal lobe

Answer 21

ØUnderstanding language (Wernicke’s area), allows processing of words into coherent thought and understanding of written or spoken words
ØMemory
ØHearing
ØSequencing and organization

Question 22

Hypothalamus

Answer 22

˜Hypothalamus - is located in the floor of the third ventricle and is the master control of the autonomic system. It plays a role in controlling behaviors such as hunger, thirst, sleep, and sexual response. It also regulates body temperature, blood pressure, emotions, and secretion of hormones.

Question 23

Pituitary gland

Answer 23

Pituitary gland - lies in a small pocket of bone at the skull base called the sella turcica. The pituitary gland is connected to the hypothalamus of the brain by the pituitary stalk. Known as the “master gland,” it controls other endocrine glands in the body. It secretes hormones that control sexual development, promote bone and muscle growth, respond to stress, and fight disea

Question 24

Pineal gland

Answer 24

˜Pineal gland - is located behind the third ventricle. It helps regulate the body’s internal clock and circadian rhythms by secreting melatonin. It has some role in sexual development.

Question 25

Thalamus

Answer 25

Thalamus - serves as a relay station for almost all information that comes and goes to the cortex (Fig. 5). It plays a role in pain sensation, attention, alertness and memory.

Question 26

LOC and Orientation

Answer 26

ØDetermine level of consciousness (LOC) by observing the patient’s responsiveness and mental status
ØA change in LOC is the FIRST indication that central neurologic function has declined!
ØThe patient who is described as ALERT is awake and responsive
ØA patient may be alert but not oriented to person, place, or time.
ØPatients who are less alert are labeled lethargic, stuporous, or comatose
˜A LETHARGIC patient is drowsy or sleepy but easily awakened.
˜A STUPOROUS patient is arousable only with vigorous or painful stimulation
˜A COMATOUS patient is unconscious and cannot be aroused
˜To best identify the patient’s level of cognitive function or LOC, describe behavior as response to stimulation
˜Remember advanced age, time of day, drug therapy, and the need for sleep, glucose, or oxygen may affect these responses

Question 27

Memory

Answer 27

˜Memory and attention
ØIs the most important part of the neurological assessment
˜Loss of memory, especially recent memory, tend to be an early sign of neurologic problems
˜Three types of memory
ØRemote or long term ask about date of birth, schools attended etc.
ØRecall or recent memory ask time or date of appointment
ØImmediate or new memory ask to repeat 3 words and ask again about 5 minutes later.
˜Language and higher levels of cognition can be assessed during the assessment

Attention: Have patient repeat a series of three numbers, adding one number each time until they can do seven or eight. Do it again but backwards.

Count backwards From 100 by 7, Stop them at 65.

Question 28

Cranial nerve assessment

Answer 28

ØAre tested to establish a baseline from which to compare progress or deterioration
ØNot routinely tested unless the patient has suspected problem affecting one or more of the cranial nerves

Question 29

Sensory assessment

Answer 29

Is performed for patients with problems affecting the spinal cord or spinal nerves such as trauma, intervertebral disk disease, Guillain Barre syndrome, tumor, infection, stenosis or transverse myelitis

˜The sensory assessment includes pain, superficial and deep sensation, light touch, and proprioception
˜Pain and light touch are the most commonly assessed
˜Pain and temperature sensations are transmitted by the same nerve endings. If one sensation is tested and found to be intact, it is safe to assume the other sensation is intact (unless a spinal cord injury)
ØDiabetes or peripheral vascular disease may have sensory loss and not be aware of it
˜Pain sensation is assessed with a sharp or dull object such as a cotton tip of end of a paper clip randomly

Question 30

Motor function

Answer 30

˜Observe for involuntary tremors or movements
˜Abnormalities can indicate certain diseases such as multiple sclerosis or effects of psychrotropic drugs
˜Measure hand strength and resistance

Question 31

Cerebellar function

Answer 31

Fine motor coordination of muscle activity (run heel of one foot down the shin of the other leg, palm up and then down quickly, and arms out at side touch finger to nose with eyes open and closed

Test gait and equilibrium.
Romberg tests proprioception

Question 32

Romberg sign

Answer 32

˜Romberg sign is a test for equilibrium asking the patient to stand and close eyes. If sways this is positive.

Question 33

Babinskis sign

Answer 33

˜Babinski’s sign is abnormal in anyone older than 2 years and represents the presence of CNS disease. This is dorsiflexion of the great toe and fanning of the other toes.
˜Babinski’s sign can occur with drug and alcohol intoxication, after a seizure, MS or liver disease

Question 34

Glasgow coma scale

Answer 34

˜The Glasgow Coma Scale (GSC) is used to describe the patient’s LOC. The tool is reliable and establishes baseline data for eye opening, motor response and verbal response

˜The GCS the patient is assessed and assigned a numerical score for each area
˜A score of 15 represents normal neurological functioning
˜A score of 7 represents a comatose state
˜The lower the score, the lower the patient’s LOC
˜If the patient is not awake and responding to commands, it may be necessary to use painful stimuli such as supraorbital (over eyes) pressure, trapezius muscle squeeze, mandibular (jaw) pressure, or sternal (breastbone) rub
˜In addition to using the GCS, observe the patient for other sign of altered mental status. These changes include reports of headache, restlessness, irritability, or being unusually quiet; slurred speech, and change in LOC

Question 35

Late mental deterioration sign

Answer 35

˜Decerebrate or decorticate posturing, as well as pinpoint or dilated or nonreactive pupils, is a LATE mental deterioration sign. Notify the health care provider IMMEDIATELY of any change in mental status to possibly prevent further decline!

Question 36

Decorticate

Answer 36

˜Decortication is abnormal posturing seen in the patient with lesions that interrupt the corticospinal pathways (cervical spinal tract or cerebral hemisphere). The arms, wrists, and fingers are flexed with internal rotation and plantar flexion of legs. Refer to Memory Notebook Vol. 1, 5th Ed. p. 96, and Vol. 2, 4th Ed. p. 116. Remember the C’s arms flex like C’s towards the “cord”

Question 37

Decerebrate

Answer 37

˜Decerebration is abnormal posturing and rigidity characterized by extension of the arms and legs, pronation of the arms, plantar flexion, and opisthotonos (body spasm in which body is bowed forward). Decerebration is usually associated with problems within midbrain or srainstem. Refer to Memory Notebook Vol. 1, 5th Ed. p. 96, and Vol. 2, 4th Ed. p. 116. Remember the E’s arms extend like E’s

Question 38

MRI

Answer 38

˜Magnetic Resonance Imaging (MRI): Produces images better than CT and does not use ionizing radiation but, magnetic fields. MRI does NOT use an ionizing agent but if contrast is used to enhance the image Gadolinium is a non-iodine based contrast medium. Still ask the patient if they have had any allergies to any dye used in another procedure such as iodine or shellfish because they may have a similar reaction.
ØNo metal objects may enter the MRI room. MRI contraindicated for patients with cardiac pacemakers, other implanted pumps or devices, and ion-containing metal aneurysm clips, or transdermal patches.
ØVascular stents, intravascular catheter (IVC) filters, and metal vascular embolic devices, may be scanned immediately or after a period of time depending on the manufacturer
ØContraindicated in patients who are confused, agitated, unstable vital signs, on life support, older tattoos that contain lead
ØNo special postprocedure or follow-up care is required. Can return to activities of daily living.

Question 39

Contrast reaction

Answer 39

Hives, Flushing, thrombosis, and bleeding from site. patients are pre treated with steroids.

Question 40

PET scan

Answer 40

˜Positron emission tomography (PET) provides information about the function of the brain, specifically glucose and oxygen metabolism and cerebral blood flow
ØInjects IV deoxyglucose which is tagged as an isotope

NPO the night before a morning test for four hours before an afternoon test. If diabetics have the tested in the morning before taking their meds. During this 2 to 3 hour procedure the patient may be blindfolded and have earplugs inserted. They may be asked to perform certain mental functions

Question 41

Cerebral angiography

Answer 41

˜Cerebral angiography
ØIs done to visualize the cerebral circulation to detect blockages in the arteries and veins in the brain, neck, and head
ØA contrast medium is injected into an artery (usually the femoral) to identify aneurysms, traumatic injuries, strictures/occlusions, tumors, blood vessel displacement, and arteriovenous (AV) malformation.
ØPrecautions for the injection of contrast agent include asking the patient about allergies to shellfish or iodine and risk factors for contrast-induced neuropathy (renal damage)
•Pre-existing renal disease
•Diabetic neuropathy
•Heart failure
•Dehydration
ØChecking the patient’s creatinine level if greater than 1.5 mg/dL are at a greater risk for contrast induced neuropathy and notify physician.
ØContrast reaction include hives and flushing, thrombosis (clotting), and bleeding from entry site. Pre-treat with steroids
ØFollow organizations policy for informed consent.
ØIncrease oral or IV fluids if not contraindicated to flush kidneys of contrast.

Post procedure: check for bleeding and swelling, apply ice pack, keep the extremities straight, maintain pressure dressing for two hours. Evaluate for adequate circulation.

Question 42

Lumbar puncture

Answer 42

˜Insertion of spinal needle into the subarachnoid space (between the third and fourth lumbar vertebrae)
˜Contraindicated in patients with increased intracranial pressure due to the danger of sudden release of cerebral spinal fluid (CSF)
˜Not performed in patients with skin infections at or near the puncture site because of the danger of introducing infective organisms into the CSF
˜Empty bladder
˜Position on side flex knees to chest, important to not move and be still
˜Spinal headache possible from spinal tap

Question 43

CSF

Answer 43

Circulate, surroundings, and cushions the brain and spinal cord. It is continuously produced by the choroid plexus.
˜Pressure less than 20 cm H2O
˜Color/Appearance clear, colorless
ØPink-red to orange RBC’s present
ØYellow bilirubin present owing to hemolysis
ØBrown methemeoglobin present previous meningeal hemorrhage
ØUnclear or hazy cell count is elevated
˜Cells
Ø0-5 small lymphocytes/mm3
ØProteins 15-45 mg/dL (up to 70mg/dL older adults

Question 44

Medulla

Answer 44

Cardiac slowing center, respiratory Center, cranial nerves nine 10, 11 and 12 and portions of cranial nerves seven and eight

Question 45

EEG

Answer 45

Electroencephalogram˜
Graphically records the electrical activity of the cerebral hemispheres
˜Sleep deprivation requirement
˜Anticonvulsants possibly withheld
No caffeine, wash hair that morning, don’t apply anything to it.
16-24 electrodes attached with a jelly

Question 46

Midbrain

Answer 46

Contains the cerebral aqueduct of Sylvius. May abolish pain when stimulated. Cranial nerve three and four located here

Question 47

Sympathetic nervous system

Answer 47

As part of the autonomic nervous system. It is the fight or flight system. They originate in the gray matter of the spinal cord from T1 thru L2 or L3. It also inhibits functions that are not needed during fight or flight.

Question 48

Parasympathetic nervous system

Answer 48

Part of the autonomic nervous system. They originate in the gray matter of the sacral area from S2 through S4 plus portions of cranial nerves three, seven, nine, and 10. It can slow body functions when needed.

Question 49

PONS

Answer 49

Cardiac acceleration and vasoconstriction centers. Pneumotaxic Center help control respiratory pattern and rate. Cranial nerves five, six, seven, and eight

Question 50

Pronator drift

Answer 50

Close eyes and hold arms perpendicular to the body with the palms up for 15 to 30 seconds. If there is a cerebral or brainstem reason for muscle weakness the arm on the week side will start to fall or drift with the palm turning inward.

Question 51

Reflexes

Answer 51

2 normal
1 hypoactive
3 stronger than normal
0 absent
Clonus Is the sudden, brief, jerking contraction of a muscle or muscle group often seen in seizures

Asymmetry of reflexes is an important finding because it probably indicates a disease process.

Question 52

Rapid neuro check

Answer 52

Is completed when the patient is admitted to a healthcare facility on an emergent basis. Is also part of the ongoing assessment. The typical flowsheet contains data related to level of consciousness, orientation, movement of arms and legs, and pupil size and reaction to light. May include the GCS

Question 53

Changes of the nervous system related to aging

Answer 53

Slower processing time. Recent memory loss. Decreased touch sensation. Change in perception of pain. Change in sleep patterns. Altered balance and decreased coordination. Increased risk for infection.

Intellect does not decline as a result of aging. Cognitive decline is frequently caused by drug interactions or toxicity or by in adequate oxygen supply to the brain.

Question 54

Cutaneous/superficial reflexes

Answer 54

Include the plantar reflexes and occasionally the abdominal reflexes. The plantar reflex is tested with a pointed but not sharp object such as the end of the reflex hammer. The normal response is plantar flexion of all toes. Dorsiflexion of the great toe and fanning out is a babinskis sign. Testing abdominal reflex, stroke the patient’s abdomen and all four quadrants diagonally toward the umbilicus. The umbilicus should deviate towards the stimulus. Obesity may mask the reflex.

Question 55

MRA

Answer 55

Magnetic resonance spectroscopy

It is used to evaluate bloodflow and blood vessel abnormalities such as arterial blockage, intracranial aneurysm, AV malformations. Precautions are the same as an MRI

Question 56

Contrast precautions

Answer 56

May need informed consent. Determine food and fluid restrictions before the test. Ask about allergies to contrast, shellfish, or iodine. Determine risk factors such as pre-existing renal disease, diabetic nephropathy, heart failure, dehydration. Ask about drugs that interfere with renal perfusion such as Metformin. Interventions include notifying the doctor if the patient has a risk factor. Make sure the creatinine level is less than 1.5. Document the date time the name of the doctor and actions he prescribed.

Question 57

Deep tendon reflexes

Answer 57

Including the biceps, triceps, brachioradialis, quadriceps muscles, the patient must be relaxed