Chapter Twenty-two Neurological system

PURPOSE

In this chapter you will review the structure and function of the components of the neurological system including the cranial nerves, cerebellar system, motor system, sensory system and reflexes. You will develop an understanding of the rationale for and methods of examination of the neurological system and learn to accurately record and document the assessment. Together with the mental status assessment presented in Chapter 21, you should be able to perform a complete assessment of the neurological system.

KEY CONCEPTS

• Anatomical structure and functions of the head and neck

• Components of the nervous system

• Related neuroanatomy and physiology

• The central and peripheral nervous systems

• Cranial nerves

• The motor system

• The sensory system

• Deep tendon reflexes

• Neurological abnormalities

• Types of neurological assessment (neurological observations)

• Developmental considerations during neurological assessment

While you are completing your reading assignment, ensure you understand each of the key concepts listed above.

READING ASSIGNMENT

Jarvis, Forbes & Watt (JF&W): Jarvis’s Physical Examination and Health Assessment, Chapter 22, pp 575–643.

GLOSSARY

After reading the corresponding chapter in the text, learn the following terms. You should be able to cover the definition on the right and state the associated definition in your own words.

Amnesia loss of memory

Anaesthesia absent touch sensation

Analgesia absent pain sensation

Aphasia true language disturbance, defect in word choice and grammar or defect in comprehension; defect is in higher integrative language processing; is the loss of the ability to speak or write coherently or to understand speech or writing

Astereognosis inability to identify object correctly

Ataxia uncoordinated or unsteady gait, inability to perform coordinated movements

Athetosis bizarre, slow, twisting, writhing movement, resembling a snake or worm

Atrophy abnormally small muscle with a wasted appearance; occurs with disuse, injury and lower motor neuron disease

Aura a subjective sensation that precedes a seizure; it could be auditory, visual or motor

Chorea sudden, rapid, jerky, purposeless movement involving limbs, trunk or face

Clonus rapidly alternating involuntary contraction and relaxation of a muscle in response to sudden stretch

Coma state of profound unconsciousness from which the person cannot be aroused

Contralateral opposite side of the body

Decerebrate rigidity upper extremities stiffly extended, adducted, internal rotation, palms pronated; lower extremities stiffly extended, plantar flexion; teeth clenched; hyperextended back; more ominous than decorticate rigidity; indicates lesion in brainstem at midbrain or upper pons

Decorticate rigidity upper extremities—flexion of arm, wrist and fingers; adduction of arm, i.e. tight against thorax; lower extremities—extension, internal rotation, plantar flexion; indicates hemispheric lesion of cerebral cortex

Dysarthria difficulty forming words; distorted speech sounds; speech may sound unintelligible; basic language (word choice, grammar, comprehension) intact

Dysmetria the inability to control range of motion of muscles; clumsy movement with overshooting the mark; occurs with cerebellar disorders or acute alcohol intoxication

Dysphagia difficulty with swallowing

Dysphasia difficulty with language comprehension or expression impairment in speech consisting of lack of coordination and inability to arrange words in their proper order

Fasciculation rapid continuous twitching of resting muscle without movement of limb

Flaccidity loss of muscle tone, limp; decreased resistance, hypotonic

Graphaesthesia ability to ‘read’ a number by having it traced on the skin

Hemiplegia spastic or flaccid paralysis of one side of body and extremities; loss of motor power (paralysis) on one side of the body, usually caused by a cerebrovascular accident; paralysis occurs on the side opposite the lesion

Hydrocephalus increased head size due to increased cerebrospinal fluid

Hyper (prefix) increased

Hyperalgesia increased pain sensation

Hypertrophy increased size and strength of muscle; occurs with isometric exercise

Hypo (prefix) decreased

Hypoalgesia decreased pain sensation

Ipsilateral same side of the body

Lower motor neuron motor neuron in the peripheral nervous system with its nerve fibres extending out to the muscle and only its cell body in the central nervous system

Microcephalic head size below norms for age

Macrocephalic an enlarged head for age, or rapidly increasing in size

Myoclonus rapid sudden jerk of a muscle

Nuchal rigidity stiffness in cervical neck area

Nystagmus back-and-forth oscillation of the eyes

Opisthotonos prolonged arching of back, with head and heels bent backward, due to meningeal irritation

Paresis is a partial or incomplete paralysis; weakness or diminished strength

Paralysis loss of strength; a loss of motor function due to a lesion in the neurological or muscular system or loss of sensory innervation; problem with motor nerve or muscle fibres

Paraplegia impairment or loss of motor and/or sensory function in the lower half of the body

Paraesthesia abnormal sensation, i.e. burning, numbness, tingling, prickling, crawling skin sensation

Point localisation ability to discriminate exactly where on the body the skin has been touched

Proprioception sensory information concerning body movements and position of the body in space

Ptosis drooping of the eyelid that occurs with damage to or dysfunction of cranial nerve III

Spasticity increased tone or hypertonia; increased resistance to passive lengthening; then may suddenly give way (clasp-knife phenomenon)

Stereognosis ability to recognise objects by feeling their forms, sizes and weights while the eyes are closed

Syncope a sudden loss of strength, a temporary loss of consciousness (a faint) due to lack of cerebral blood flow

Tic repetitive twitching of a muscle group at inappropriate times, e.g. wink, grimace

Tremor an involuntary shaking, vibrating or trembling; involuntary contraction of opposing muscle groups resulting in rhythmic movement of one or more joints

Two-point discrimination ability to distinguish the separation of two simultaneous pinpricks on the skin

Upper motor neuron nerve located entirely within the central nervous system

Vertebra prominens the long spinous process of C7 vertebra that is palpable when the head is flexed

Vertigo rotational spinning caused by neurological disease in the vestibular apparatus in the ear or in the vestibular nuclei in the brainstem

STUDY GUIDE

After completing the reading assignment, you should be able to answer the following questions in the spaces provided.

1. State the function of the skull.

_____________________________________________________________

2. Label the figure of the skull with the following:

1. Coronal suture

2. External acoustic meatus

3. Frontal bone

4. Lambdoid suture

5. Mandible

6. Mastoid process

7. Maxilla

8. Nasal bone

9. Occipital bone

10. Parietal bone

11. Sphenoid bone

12. Temporal bone

13. Temporomandibular joint

14. Zygomatic bone

3. Explain how the cranium is supported and by which structures.

_____________________________________________________________

4. Explain the boundaries of the neck and list the structures contained within the neck.

_____________________________________________________________

5. Describe in detail the two divisions of the nervous system.

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6. List the major function(s) of the following components of the central nervous system:

cerebral cortex—frontal lobe

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cerebral cortex—parietal lobe

_____________________________________________________________

cerebral cortex—temporal lobe

_____________________________________________________________

cerebral cortex—Wernicke’s area

_____________________________________________________________

cerebral cortex—Broca’s area

_____________________________________________________________

basal ganglia

_____________________________________________________________

thalamus

_____________________________________________________________

hypothalamus

_____________________________________________________________

cerebellum

_____________________________________________________________

midbrain

_____________________________________________________________

pons

_____________________________________________________________

medulla

_____________________________________________________________

spinal cord

_____________________________________________________________

7. Fill in the labels on the following illustration.

8. Sensation travels in the afferent fibres in the peripheral nerve, then through the posterior (dorsal) root, then into the spinal cord. There, the sensation may take one of two routes: 1. The spinothalamic tract or 2. The posterior (dorsal) columns. Identify the sensations each of these pathways transmit and the route they take to mediate a response.

_____________________________________________________________

9. Explain how organ pain is felt from the heart, liver or spleen when there is no representation of these organs on the sensory homunculus.

_____________________________________________________________

10. Identify then describe each of the 3 major motor pathways in the CNS including the type of movements mediated by each.

_____________________________________________________________

11. Differentiate between an upper motor neuron and a lower motor neuron.

_____________________________________________________________

12. List the four types of reflexes and provide an example of each.

_____________________________________________________________

13. Trace the transmission of an impulse from initiation of sensation to response in a deep tendon reflex arc. As you trace the transmission, identify each of the 5 components of a reflex arc.

_____________________________________________________________

14. Fill in the gaps in relation to the spinal nerves:

There are ______________ of spinal nerves that arise from the length of the spinal cord and supply______________.

There are:_______________cervical, _______________thoracic, _______________lumbar, _______________sacral and_______________ coccygeal.

They are_______________ nerves because they contain both_______________ and_______________ fibres.

The nerves enter and exit the cord through roots: sensory afferent fibres through the ______________ or ______________roots; motor efferent fibres through the______________or______________roots. ______________is the cutaneous distribution of the various spinal nerves.

A_______________ is an identified skin area that is supplied mainly from_ through a particular spinal nerve.

15. Circle True or False to answer the following statements concerning developmental considerations. If the answer is false, state the correct answer

16. Describe the characteristics and duration of each of the following headache types.

meningitis or encephalitis

_____________________________________________________________

migraine

_____________________________________________________________

cluster headaches

_____________________________________________________________

tension headaches

_____________________________________________________________

17. Identify at least 5 health history questions you would ask a patient concerning headaches they have.

_____________________________________________________________

18. When performing a neurological examination on an infant, why is it important to ask the parent if the infant has had:

any seizures?

_____________________________________________________________

exposure to lead-based paints?

_____________________________________________________________

19. Name each of the 3 types of neurological examinations; state when they would be performed, on whom, and what is examined with each.

_____________________________________________________________

20. A previously alert patient’s level of consciousness appears to be deteriorating, as they no longer open their eyes spontaneously. State, in order, how you would increase the stimulus to elicit a response.

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21. Differentiate between localising, decorticate and decerebrate movements.

_____________________________________________________________

22. When assessing the pupils:

What characteristics should be noted?

_____________________________________________________________

Explain the pupillary light reflex.

_____________________________________________________________

List factors that may affect pupillary size, shape and response.

_____________________________________________________________

How and why is pupil size measured?

_____________________________________________________________

How is pupil assessment documented?

23. Explain the vital sign changes in the Cushing reflex.

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24. Describe the purpose of the Glasgow Coma Scale and each of the three divisions being assessed.

Purpose:_________________________________________

_____________________________________________________________

1. ________________________________________________________

_____________________________________________________________

2. ________________________________________________________

_____________________________________________________________

3. ______________________________________________________

_____________________________________________________________

25. List the method of testing for each of the 12 cranial nerves in the adult.

1. _____________________________________________________________

2. _____________________________________________________________

3. _____________________________________________________________

4. _____________________________________________________________

5. _____________________________________________________________

6. _____________________________________________________________

7. _____________________________________________________________

8. _____________________________________________________________

9. _____________________________________________________________

10. _____________________________________________________________

11. _____________________________________________________________

12. _____________________________________________________________

26. Fill in the name of each cranial nerve, and label it as S (sensory), M (Motor), or MX (mixed).

27. Briefly describe each of the following cerebellar tests and state what a positive test may indicate:

Romberg

_____________________________________________________________

rapid alternating movement

_____________________________________________________________

finger-to-nose test

_____________________________________________________________

28. Briefly describe the method of testing the sensory system for pain, temperature, touch, vibration and position. Hint: pain, temperature, touch test the spinothalamic tract; vibration and position test the posterior column.

_____________________________________________________________

29. Outline the 4-point grading scale for deep tendon reflexes.

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30. State the spinal level that will enable assessment of intactness of the reflex arc associated with the following:

biceps reflex ______________

triceps reflex ______________

brachioradialis reflex ______________

quadriceps reflex ______________

Achilles reflex ______________

31. Briefly describe testing of each of the following newborn reflexes and state when they disappear.

rooting reflex

_____________________________________________________________

sucking reflex

_____________________________________________________________

palmar grasp

_____________________________________________________________

plantar grasp

_____________________________________________________________

Babinski’s reflex

_____________________________________________________________

tonic neck reflex

_____________________________________________________________

Moro reflex

_____________________________________________________________

stepping reflex

_____________________________________________________________

32. Describe patient presentation regarding their level of consciousness that would be graded as:

lethargic or somnolent

_____________________________________________________________

obtunded

_____________________________________________________________

stupor or semi-coma

_____________________________________________________________

coma

_____________________________________________________________

33. In question 11 you identified the difference between upper and lower motor neurons. Explain the type of reflex response you would expect to see with an upper motor neuron lesion versus a lower motor neuron lesion.

_____________________________________________________________

NOTES

REVIEW QUESTIONS

This test is for you to check your own mastery of the content. The answers are provided in Appendix A.

1. The medical record indicates that a person has an injury to Broca’s area. When meeting this person you expect:

a. difficulty speaking

b. receptive aphasia

c. visual disturbances

d. emotional lability

2. The control of body temperature is located in:

a. Wernicke’s area

b. the thalamus

c. the cerebellum

d. the hypothalamus

3. To test for stereognosis, you would:

a. have the person close their eyes, then raise the person’s arm and ask them to describe its location

b. touch the person with a tuning fork

c. place a coin in the person’s hand and ask them to identify it

d. touch the person with a cold object

4. During the examination of an infant, use a cotton-tipped applicator to stimulate the anal sphincter. The absence of a response suggests a lesion of:

a. L2

b. T12

c. S2

d. C5

5. During a neurological examination, the tendon reflex fails to appear. Before striking the tendon again, the nurse might use the technique of:

a. two-point discrimination

b. reinforcement

c. vibration

d. graphaesthesia

6. The National Stroke Foundation Australia (2010) recommends the FAST test as an easy way to recognise and remember the signs of stroke. What does the acronym FAST stand for:

a. Fear, Arms, Stand, Test

b. Face, Arms, Speech, Time

c. Face, Artery, Stroke, Time

d. Face, Artery, Slurring, Time

7. Cerebellar function is assessed by which of the following tests?

a. muscle size and strength

b. cranial nerve examination

c. coordination—hop on one foot

d. spinothalamic test

8. To elicit a Babinski reflex:

a. gently tap the Achilles tendon

b. stroke the lateral aspect of the sole of the foot from heel to the ball

c. present a noxious odour to a person

d. observe the person walking heel to toe

9. A positive Babinski sign is:

a. dorsiflexion of the big toe and fanning of all toes

b. plantar flexion of the big toe with a fanning of all toes

c. the expected response in healthy adults

d. withdrawal of the stimulated extremity from the stimulus

10. The cremasteric response is:

a. positive when disease of the pyramidal tract is present

b. positive when the ipsilateral testicle elevates upon stroking of the inner aspect of the thigh

c. a reflex of the receptors in the muscles of the abdomen

d. not a valid neurological examination

11. Senile tremors may resemble parkinsonism, except that senile tremors do not include:

a. nodding the head as if responding yes or no

b. rigidity and weakness of voluntary movement

c. tremor of the hands

d. tongue protrusion

12. People who have Parkinson’s disease usually have which of the following characteristic styles of speech?

a. a garbled manner

b. loud, urgent

c. slow, monotonous

d. word confusion

13. Match Column A with Column B.

PRACTICAL SKILLS IN THE LABORATORY/CLINICAL SETTING

Assessment of the neurological system is an important assessment area for nurses. You will perform neurological assessment on a routine basis as an ongoing assessment or use it as a screening tool for your patients. You have reviewed the structure and function of many of the elements involved in the nervous system. Now it is time to practise the knowledge and skills you developed related to performing a comprehensive neurological assessment as you worked through this chapter.

You are now ready for the clinical component of the neurological system.

The purpose of the clinical component is to practise the regional examination on a peer in the skills laboratory or a patient in the clinical setting

CLINICAL OBJECTIVES

At the completion of the clinical laboratory session, with further practice and self-directed learning you should be able to:

1. demonstrate knowledge of the symptoms related to the neurological system by obtaining a neurological health history from a peer or patient

2. demonstrate the techniques used in examination of the neurological system. Beginning practitioners will be able to perform ongoing neurological observations and use of the Glasgow Coma Scale. With more experience and practice you will develop skills to assess the cranial nerves, cerebellar function, sensory system, motor system and deep tendon reflexes

3. record the history and physical examination findings accurately, reach an assessment of the health state and develop a plan of care.

INSTRUCTIONS

1. Form pairs.

2. Prepare the examination setting and gather your equipment for an ongoing neurological examination or as directed by your instructor.

3. Wash your hands.

4. Gain consent to perform the examination from either your peer or the patient.

5. Practise the neurological health history interview and the steps of the ongoing neurological examination on a peer in the skills laboratory or a patient in the clinical setting, providing appropriate instructions as you proceed.

6. Record your findings using the regional write-up worksheet.

7. Swap roles and repeat steps 2–6.

8. Discuss your assessment techniques, findings and performance with your peer to develop a complete understanding of the process.

9. Document your findings using the SOAP format.

NOTES

REGIONAL WRITE-UP WORKSHEET-ONGOING NEUROLOGICAL STATUS

Date______________

Interview conducted by ______________

Designation ______________

Patient ____________________________Age_______________ Gender______________

Occupation ________________________________Medical Record Number______________

I. Health history

1. Any unusual frequent or unusually severe headaches?______________

Location_______________ When started? ______________

How often? ______________

Pattern_______________ Describe characteristics ______________

Type of pain?_____________How long do they last? ______________

Precipitating factors?_____________Associated factors? ______________

Family history?_____________Coping strategies ______________

2. Do you have neck pain?______________

Onset?_____________Location? ______________

Precipitating factors?_____________Associated factors? ______________

3. Do you have pain anywhere else? ______________

Score?_____________Quality? ______________

Onset/duration?_____________Relief? ______________

Effect on ADL’s ______________

4. Ever had any head injury?______________

Show where_______________ Any loss of consciousness? ______________

5. Ever feel dizzy? ______________Vertigo?______________

6. Ever had any seizures?______________

Onset?_____________How often? ______________

Course and duration? ______________

Warning signs?_____________Type? ______________

Precipitating factors? ______________

Medications?_____________Coping strategies? ______________

7. Any tremors in hands or face? ______________

Worse with anxiety?_____________Relieved with rest? ______________

Medications? ______________

8. Any weakness in any body part? ______________

Local or generalised? ______________

9. Any problem with coordination?______________

Problems with balance when walking?_____________Any falls? ______________

10. Any numbness or tingling?______________

Where?_____________When? ______________

11. Any problem swallowing?______________

With solids?_____________With liquids? ______________

Excessive saliva? ______________

12. Any problem speaking?______________

Problems forming words?_____________Problems getting message across? ______________

13. Significant past history? ______________

Any stroke, spinal cord injury, meningitis, congenital defect, alcoholism? ______________

14. Any environmental/occupational hazards, e.g. insecticides? ______________

Lead?_____________Other? ______________

II. Physical examination

Most hospitals and institutions have specific charts to guide this form of neurological assessment and for ease of recording the data. Generally, the assessment data is presented in graphic form, which usually includes the Glasgow Coma Scale, pupillary response and vital signs. Your instructor may also provide you with an example used in your health service so you can practise recording your findings.

A. Ongoing neurological observations

1. Mental status assessment using minimental examination as needed. Refer to MMSE in JF&W, Chapter 21, Table 21.1, pp 562–563.

Using Glasgow Coma Scale on the next page

2. Level of consciousness

Ease of arousal/state of awareness

Orientation_______________ Person ______________

Place_______________ Time ______________

Verbal responses ______________

3. Motor function

Voluntary motor function—obeys commands ______________

Hand grasp—muscle strength ______________

Palmar drift? ______________

Straight leg raise? ______________

Movement in response to painful stimulus? ______________

4. Pupillary response

Size_______________ shape_______________ symmetry ______________

Direct light reflex_______________ Consensual light reflex ______________

Pupillary light reflex ______________

5. Vital signs—Record on next page

Glasgow Coma Scale

Pupils

Pupil size in mm

Observations

Neuro assessment–motor function

Further assessment for advanced practice

NOTE: Your facilitator may ask you to practise some sections, all sections or none at all. Please check prior to the laboratory session to enable preparation if required.

Preparation	Equipment needed
In addition to the assessment strategies above, use the following sequence for a screening or complete neurological examination. 1 Mental status (see Ch 21) 2 Head and neck 3 Cranial nerves 4 Motor system 5 Sensory system 6 Reflexes Position the person sitting up with the head at your eye level.	Neurological observations chart Penlight torch Tongue blade Cotton swab Cotton ball Tuning fork (128 Hz or 256 Hz) Percussion hammer (Possibly) familiar aromatic substances, e.g. peppermint, coffee, vanilla

Refer to JF&W, Chapter 22, pp 596–616 for the adult examinations and pages 616–627 for infant and paediatric examinations.

B. Screening and complete neurological examination for advanced practice

A. Cranial nerves

I______________________

II ______________

III, IV, VI ______________

V______________

VII ______________

VIII ______________

IX, X ______________

XI ______________

XII ______________

B. Motor system

1. Muscles

Size, strength, tone ______________

Involuntary movements ______________

2. Cerebellar function

Gait ______________

Romberg test ______________

Rapid alternative movements ______________

Finger-to-finger test ______________

Finger-to-nose test ______________

Heel-to-shin test ______________

C. Sensory system

1. Spinothalamic tract

Pain ______________

Temperature ______________

Light touch ______________

2. Posterior column tract

Vibration ______________

Position (kinaesthesia) ______________

Tactile discrimination ______________

Stereognosis ______________

Graphaesthesia ______________

Two-point discrimination ______________

D. Reflexes

REGIONAL DOCUMENTATION (SOAP)–NEUROLOGICAL SYSTEM

Summarise your findings using the SOAP format.

Subjective (Reason for seeking care, health history)

Objective (Physical exam findings)

Assessment (Assessment of health state or problem, diagnosis)

Plan (Diagnostic evaluation, follow-up care, patient teaching)

Record reflexes/findings on diagram below