Neurological Assessment & Diagnostic Studies

NET 2420Neuro Lecture HandoutS. Compton RN, MSN

Nursing History• Current Health History

– Headaches, memory and concentration, visual disturbances, hearing, balance, dizzy spells, speech, muscle strength, abnormal sensations

• Past Health History– Head injury, spinal cord injury, surgery, seizures

• Family History– Neurological diseases, headaches, HTN, stroke,

DM• Social History and Habits

– Diet, vitamin deficiencies, ability to read or concentrate, exposure to toxins or chemicals, alcohol or drug use, sexual difficulties, sleep problems

• Medication History-neuro as well as all others

Complete Neurological Assessment

5 Components

• Cerebral Function • Cranial Nerve Function: I-XII• Cerebellar and Motor Function• Sensory System• Reflexes

Neuro Check

• Level of consciousness (LOC)• Pupil response and size• Verbal responsiveness• Extremity strength and movement• Vital signs Establishing BASELINE and regularly re-

evaluating key indictors reveals trends and detects changes warning signs of problems

Cerebral Function• Level of consciousness:

– Level of arousal: Subcortical RAS• Alert lethargic unresponsive• Auditorytactile painful stimuli to elicit

response– Level of orientation: Cortex activity

• Person, place, time• Speech

– Quality: Clear, slurred– Verbal responses appropriate or nonsensical – Ability to understand and follow commands– Awareness of and difficulties with communication

Cerebral Function:Verbal Responsiveness and

Speech• Dysarthria: difficulty with mechanics of speech• Aphasia:

– TEMPORAL-receptive• Inability to understand or process speech

Wernicke’s• Auditory: spoken word• Visual: written word

– FRONTAL-expressive• Inability to form or use language Broca’s Area• Spoken OR written or BOTH

– GLOBAL: both receptive and expressive

Mini-Mental State

• Widely used tool• Assesses only cognitive abilities

– LOC, abstract reasoning, arithmetic calculations, writing ability, memory and judgment

• Objective score based on results

Cranial Nerves (CNs)Smeltzer & Bare Table 60-5 p 1837

• CN I- Olfactory• CN II- Ophthalmic• CN III-

Occulomotor*• CN IV- Trochlear*• CN V- Trigeminal• CN VI- Abducens*

• CN VII- Facial• CN VIII-

Vestibulocochlear• CN IX-

Glossopharyngeal• CN X- Vagus• CN XI- Spinal

Accessory• CN XII- Hypoglossal

Cranial Nerve I

• Olfactory nerve (sensory)– Vulnerable to damage in frontal head, basilar,

and facial injuries– Performed one nostril at a time– Able to correctly identify smells

Cranial Nerve II

• Optic nerve (sensory)– Visual acuity, visual

fields, ophthalmic exam of retinal structures

– Area and extent of visual field loss depends on location of problem

Visual Field Defects

Cranial Nerve III• Oculomotor nerve (motor)

– Elevation of eyelid– Muscles of eye

(with IV and VI)– Assess pupil size, shape, response to light and

accommodation parasympathetic inervation– Assesses midbrain– Normal response: PERRLA-> pupils equal round

reactive to light and accommodation • How do you test for accommodation?• If PERRL, usually no need to test

CN III, CN IV, CN VI

• Oculomotor, trochlear, abducens nerves (motor)– Assess EOM’s– Assesses midbrain and pons

CN V: Trigeminal Nerve (sensory and motor)

• Sensory: three branches:– Opthalmic, Maxillary, Mandibular

• Motor: – Muscles of mastication

• Palpate temporal and masseter muscles• Open mouth symmetry

– Corneal reflex • ? Contact wearers

CN VII: Facial Nerve (sensory and motor)

• Sensory: taste to anterior 2/3 of tongue

• Motor: Facial expression and secretion of saliva– Wrinkle forehead, raise

and lower eyebrows, smile and show teeth, puff cheeks, close eyes

– Observe for symmetry• UMN problems vs. facial

nerve paralysis

CN VIII: Acoustic Nerve (sensory)

• Vestibulocochlear nerve:– Hearing (cochlear) and balance (vestibular)

• Testing: Tuning Fork: Weber and Rinne tests– Weber: tuning fork to center of forehead:

• NORMAL: hear equally in both ears – RINNE: tuning fork to mastoid process then

auditory canal• NORMAL: hear air conduction 2X as long as

bone (Rinne positive)

CN IX and CN X

• Glossopharyngeal and Vagus

• Sensory and motor• Assess together

– Taste posterior 1/3 of tongue

– Swallowing, gag reflex– Movement of pharynx

(ahhhhh)• Assesses medulla

CN XI: Spinal Accessory Nerve • Motor

• Shrug shoulders trapezius• Turn head sternocleidomastoid

CN XII: Hypoglossal Nerve

• Motor• Tongue movements, strength

• Speech sounds: d, l, n, t

Motor Assessment

• Assess muscle strength, tone, size– Observe for decreased fine motor movements– Finger grasp, arm strength– Compare side to side

• Can indicate UMN problems:– Degenerative cerebral disease, trauma or

ischemia

• Can indicate LMN disease:– Problems within spinal cord: cord compression

or injury

Cerebellar Function

• Balance:– Tandem, heel-toe walking– Romberg test (feet together, eyes

closed)

• Coordination:– Rapid alternating movements– Finger to nose to finger test– Heel down shin

Cerebellar Function: Abnormal Findings

• Ataxia: incoordination of voluntary muscle action

• Dysdiadochokinesia: inability to do rapid alternating movement

• Dysmetria: past pointing• Positive Romberg’s sign

– Pt sways badly or loses balance positive Romberg sign• If cerebellar, pt sways with eyes open or

closed• If proprioceptive ( posterior columns)

patient OK with eyes open

Gait Disturbances

A. Spastic HemiparesisB. Spastic Paresis (Scissors Gait)C. Foot DropD. Sensory Ataxia (+ Romberg’s eyes

closed)E. Cerebellar Ataxia

(+ Romberg’s eyes open or closed)

F. Parkinsonian

Deep Tendon Reflexes Assessing Spinal Cord Level

• BicepsC5C6

• BrachioradialisC5C6

• TricepsC7C8

• AbdominalT8T9T10

• Patellar (knee-jerk)L2L3L4

• AchillesS1S2

Grading Reflexes

• Grade 0-4+ – 0 reflex absent– 2+ “normal”– 4+ CLONUS UMN

disease

• Compare side to side• Many variations• Patient must be

relaxed

Superficial Reflexes

• Graded as PRESENT or ABSENT• Corneal Reflex (CN V)

– Present Brisk blink– Loss in stroke, coma, CONTACT WEARERS– EYE PROTECTION

• Gag Reflex (CN X)– Present Elevation of uvula bilaterally– Loss in stroke– ASPIRATION PRECAUTIONS

Plantar Reflex:Babinski Response

• Stroke lateral aspect of sole of foot• NORMAL response plantar FLEXION• BABINSKI response pathological in adult

– POSITIVE BABINSKI: Dorsiflexion of great toe with fanning of other toes

– Indicates upper motor neuron disease

Grasp Reflex: Significance

• COMA: Stimulation of palm of hand– POSITIVE: Pt will grasp firmly– Will not let go to command– Indicates frontal lobe damage, thalamic

degeneration, cerebral atrophy

Sensory Function

• Assessing dorsal columns or parietal lobe – Light touch, position sense, vibration– Stereognosis: able to identify object placed

in hand– Graphesthesia– Extinction: touch one or both sides of body– Two point discrimination

• Spinothalamic tracts and parietal lobe– Pain and temperature

• Sharp or dull

Gerontologic Considerations

• Smeltzer & Bare p 1841• Structural changes

– Decreased conduction• Muscle atrophy• Diminished reflexes• Sensory alterations• Mental status changes• BUT….CANNOT ATTRIBUTE NEUROLOGIC

CHANGES TO AGE WITHOUT THOROUGH ASSESSMENT!!!!

Anatomical Planes

Skull and Spinal X-rays• C-spine films routinely ordered in

multiple trauma to rule out cervical fracture

• X-rays used to evaluate skull, spinal abnormalities, pituitary tumor

• Frequently ordered to evaluate low back pain

Computerized Tomography

• Cross sectional images brain and spine using radiation and computer

• More specific views of bone and tissue than X-rays

• Useful in detecting tumors, hemorrhages, hematomas, ventricular enlargement

• May be used with IV contrast enhancement

CT: Patient Preparation• Pt must be as motionless as possible

– Confused combative client/ pediatric considerations

• If contrast used: – ?? allergies to shellfish– NPO for 4 hours prior to test– IV started in radiology (if not already in place)

• Should remove wigs, hairpins, clips and jewelry interfere with image seen

• Test should take 30-60 minutes• Post-test: resume diet and encourage fluids if IV

contrast used

PET Scan

• Images of actual organ functioning

• Inhaled or injected radioactive substance

• Shows metabolic changes– Alzheimer’s– Brain tumors– O2 uptake after stroke

MRI: Nursing Considerations

• Use of electromagnet and radio waves• Check patient history!!

– PATIENTS WHO CANNOT HAVE MRI:• Pacemakers• Metal implants, plates, screws, or clips (old

aneurysm surgeries!)• IUD’s, metal heart valves

• SAFETY:– IV pumps, portable oxygen tanks cannot be in scan area

• Patient Preparations and teaching:– No metals: jewelry, credit cards, eyemakeup– Process takes 45 minutes to 1 hour pt. must lie still– MRI machine makes loud beating noise– Closed MRI: tight space: problems with claustophobia?

• May need Valium pre-test/ some cannot tolerate

Cerebral Angiography

• Injection of contrast medium into cerebral circulation

• Useful in detecting cause of stroke, headaches, seizures

• Femoral access most commonly used vessel

• Risk: stroke

Cerebral Angiography: Procedure & Patient Preparation

• Injection of contrast medium into cerebral circulation– Useful in detecting cause of stroke, headaches, seizures

• NPO solids 6-10 hours– Clear liquids/ water encouraged 24 hours prior

• Assess PT/ PTT– Stop anticoagulants prior to test (usually)

• Contrast dye precautions/ informed consent• Patient AWAKE; slight sedation • Femoral puncture mark peripheral pulses• Burning or flushing with contrast injection expected• Procedure will take 1-2 hours• http://www.heartcenteronline.com/myheartdr/com

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MR Angiography (MRA)

• Utilization of MR technology to view vasculature

• Same restrictions as MRI• May use contrast material

(gadolinium) but is not iodine based

Myelogram

• Injection of contrast medium into subarachnoid space x-ray visualization

• Useful for visualizing obstructions within spinal canal– Dye bathes nerve roots any

compressin of nerve roots visualized– Helpful in diagnoses of herniated discs

and spinal cord tumor

Patient Preparation• Inpatient procedure/ 23 HR• Consent form• NPO 4-8 hours prior • Probably mild sedation given; IV started• Lumbar puncture in radiology CSF aspirated• Either water based (Amipaque) or oil based

(Pantopaque) dye used– Hold phenothiazines (Phenergan),

TCA’s, SSRI’s 48 hours • Lower seizure threshhold

– X-ray table tilted• CT performed at end

Post-procedure Care

• Amipaque: not aspirated absorbed by body – HOB 30-60 degrees for 24 hours

• Pantopaque: aspirated at end of visualization– Patient flat for 24 hours (rarely used)

• Quiet activity, little stimulation• Push fluids, monitor I and O, BUN,

Creatinine• BP, RR, pulse temperature monitored • May experience nausea, headache should

diminish no Phenergan or Compazine!• No neck stiffness or confusion should occur

EEG

• Amplifies and records electrical activity in brain• Uses:

– Detecting areas of abnormal or absent brain activity• Brain tumors, hematomas, seizure activity• Determination of brain death in comatose

patient

EEG PreparationUse of Evoked Potentials

• Preparation: – Avoidance of caffeine prior to exam– No gels, sprays in hair– Must be quiet and still as possible

• Evoked Potentials: – Auditory, sensory, visual: record brain

activity in response to stimuli– Diagnostic for various disorders

Electromyography (EMG) and Nerve Conduction Velocities

(NCV)• EMG: Needle electrodes inserted into skeletal

muscles patient relaxes and contracts various muscles and action potential recorded

• NCV: Nerve stimulated with electrical impulse• Useful in studying patients with cervical or

lumbar disc disease, myasthenia gravis, muscular dystrophy (LMN diseases)

• Patient should be taught to expect some mild discomfort

Lumbar Puncture• Insertion of needle into

subarachnoid space between L2 and S1

• Withdrawal of small amount CSF for diagnostic evaluation

• Measurement of CSF pressure– Should not be

performed if evidence of greatly increased CSF pressure (papilledema)

Lumbar Puncture• Patient preparation:

– No diet or fluid restrictions– Empty bowel and bladder before– Careful instructions regarding cooperation during test – Signed consent required

• Positioning

Chart 60-4 p 1847

Lumbar Puncture

• CSF in three labeled tubes– Protein and glucose– Culture– Blood cell counts

• Post-procedure care:– Prone with pillow under abdomen for 1 hr– Flat in bed 6-24 hours (30 degrees)– Increased fluid intake– Observe site for swelling, leakage– Observe for post spinal headache

Post-Lumbar Puncture Headache

• Most common complication• CSF leaks from needle track

depleted• Increases when patient upright• AVOID: use small gauge needle/ keep

prone after• Treatment: bedrest, analgesics,

hydration– Persistent: Blood patch

CSF Fluid Analysis

• Pressure: Normal: 70-180 mmH2O (5-15mmHg)– Increased: SAH, brain tumor, viral

meningitis• Appearance: clear and colorless

– Bloody: SAH or traumatic tap (will clear)– Cloudy: infection– Orange or yellow: RBC breakdown,

elevated protein

CSF Fluid Analysis• Cell Count: 0-5 monos and no RBC’s

– Elevated monos infection, abcess, tumor, infarction, chronic illness (MS)

– RBC’s SAH or traumatic tap• Protein: 15-45 mg/dl

– Lower than plasma because of BBB– Elevated: infection, tumor, MS, degenerative

brain disease• Glucose: 50-75 mg/dl

– Elevated: DM or diabetic coma– Decreased: acute bacterial meningitis,

tumor