Week 6: The Nervous System

Question 0

Taking a case history- review of systems?

What questions do we ask?

Answer 0

• any seizures or loss of consciousness
• any episodes of dizziness or vertigo
• any difficult with or slurred speech?
• any recent difficulty with memory

Question 1

What are the four components to the Neurological Exam?

Answer 1

1. Cranial nerves
2. Motor
3. Sensory
4. Balance, co-ordination and gait

Question 2

Checking there mental state:

A few questions to ask?

Answer 2

• what is your name
• where are you?
• what is the day?

Get the opinion of the nearest relative/ carer too

Question 3

What do you observe for a nervous system examination?

Answer 3

-level of consciousness
-asymmetry (motor exam)
-gait (gait, balance and co-ordination)
Symmetry is the key so comparison with the other side is essential

Question 4

CN 1: olfactory
Cranial nerve examination
View page 326 for more info on testing these cranial nerves in bates guide to physical examination

Answer 4

-test latency of nostrils first
-testing sense of smell (olfaction)
More common causes of abnormal function: sinus, head trauma, smoking, frontal lobe tumour.

Question 5

CN 2: Optic

Answer 5

Visual acuity

• smelled chart (centra vision)
• visual field by confrontation (peripheral vision)

Opthalmoscopy 
Papilloedema: 
Causes: 
-raised ICP- causes 
-option nerve disease 
-optic neuritis

Question 6

CN 2 and 3: optic and oculomotor

Answer 6

• pupillary inspection
• pupillary reactions to light
• If reactions to light are abnormal, test near response.

Question 7

CN 3, 4 and 5: oculomotor, troachlear and abductees

Answer 7

• inspect for Ptosis
• test extraocular movements
• test for convergence

Question 8

CN 5: trigeminal

What is trigeminal Neuralgia?

Answer 8

Motor:
-palate temporal and masseters- clench side to side

Sensory:

• light touch of 3 regions
• sharp/dull of 3 regions- if abn, test temp

Corneal reflex:
-patients must look up and away, tough cornea not just conjunctiva

Trigeminal Neuralgia:

• episodes of excruciating pain lasting between seconds and 2 mins, along the distribution of one or more of its sensory divisions, most often the maxillary
• etiology: ? Compressive neuropathy
• more common in the elderly

Question 9

CN 7: facial

What are some common causes of facial nerve lesions?

Answer 9

Observe for flattening of nasolabial fold and drooping of lower eyelid
Test motor function of muscles of facial expression:
-raise eyebrows. Frown, close eyes tightly, upper and lower teeth, smile, puff out cheeks

Other functions:
Sensory: taste to anterior 2/3 of tongue
-innervation of stapedius muscle

Symptoms of facial nerve lesions:

• facial asymmetry, muscle weakness
• alteration of taste
• hyperacusis

What are some common causes of facial nerve lesions?
-trauma
-Otis media
-space occupying lesions
Bell’s palsy:
-unilateral facial paralysis of sudden onset and unknown cause
Mechanism: ? Oedema of the nerve cue to immune or viral disease, causing compression through its bony course.
Someone with it will Present to you with:
-facial weakness, sometimes complete paralysis
-affected side becomes flat and expressionless, but patients may complain instead about the seemingly twisted intact side
-no sensory loss is demonstrable.

Question 10

CN 8: vestibulocochlear
What do you test?
How do problems come about?

Answer 10

Test auditory acuity
Acoustic neuroma:
-tumours of the Schwann cell sheath of either the vestibular or cochlear nerve
-unilateral sensorineural hearing loss
-associated tinnitus (noises or ringing in the ears)
-usually associated vertigo
-headache in about half of patients

Question 11

CN 9 and 10: glossopharyngeal and vagus

Answer 11

• listen to the quality of the voice- hoarse or nasal
• enquire about any difficulty swallowing
• test movement of the uvula (deviation to either side)
• test gag reflex (sensory and motor) on both sides

Question 12

CN 11: spinal accessory

Answer 12

Observe trapezius posteriorly for atrophy/ fasciculations 
Test trapezius strength: 
-shoulder shrug against resistance 
Test SCM strength: 
-push into hand, testing opposite SCM

Question 13

CN 12: hypoglossal

Answer 13

-listen to speech (articulation)
-inspect tongue in situ for atrophy/ fasciculations
Test tongue for motor function:
-protrude tongue, move from side to side
-if lesion- deviates to which side?
Can also check tongue pushed into cheek if unsure

Question 14

Anatomy of the peripheral nerves.
How many pairs of spinal nerves are there from the spinal cord?
Each spinal nerve comprises a ___root mehh check out slide, you should know this shiiit.
Slide 4 of lecture B week 6

Answer 14

31 pairs of spinal nerves from the spinal cord:

-8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

Question 15

Examination of the motor system.
What do you inspect?
What do you assess?

Answer 15

Inspect:

• body position and involuntary movements such as tremors, tics, fasciculations
• muscle bulk, note any hypertrophy

Assess muscle tone- flex and extend the arm and the lower leg for residual tention➡ slight resistance to passive stretch

• assess power: Myotomes
• assess reflexes

Question 16

Learn the different Myotomes on slide 8 and 9

Answer 16

Yep

Question 17

Muscle strength: grading

Answer 17

• graded as 0-5
• ask the patient to me actively against your opposing resistance; assign Grade 5 if patient overcomes your opposing movement

0-no muscular contraction detected
1- a barely detectable flicker of trace of contraction
2- active movement of the body part with gravity eliminated
3- active movement against gravity
4-active movement against gravity and some resistance
5- active movement against full resistance without evident fatigue (normal muscle strength)

Question 18

Muscle strength: terminology
Partial loss =?
Complete loss= ?

Answer 18

Partial loss= weakness/ paresis (weakness of voluntary movement)
Complete loss= paralysis/ plegia

Hemiparesis (unilateral weakness UL and LL)
Hemiplegia (unilateral paralysis UL and LL)
Paraplegia (bilateral paralysis LL’s)
Quadraplegia (bilateral paralysis UL’s and LL’s )

Question 19

Memorise the deep tendon reflexes 
On slide 15 
Biceps - nerve root level? 
Supinator/ brachioradialis 
Triceps 
Patellar 
Achilles 
Medial hamstring 
Lateral hamstring

Answer 19

Ye

Question 20

Grading of reflexes
What do each of these numbers mean?
0, 1+, 2+, 3+, 4+

Answer 20

0= no response 
1+= diminished, low normal 
2+= normal 
3+= brisk response, may be Normal 
4+= very brisk, hyperactive with clonus (involuntary muscle contraction and relaxation)

Question 21

Clonus tested on the ankle. How do you do it?

Answer 21

• tested at the ankle
• knee should be flexed so tension is removed on Gastrocnemius
• rapid dorsiflexion
• clonus = foot rhythmical,y oscillates between Doris and plantar flexion
• check is the clonus is fatigueable

Question 22

DTR’s: Reinforcement

When do you use this technique?

Answer 22

• if DTR’s are symmetrically diminished or absent, use either of the 2 common reinforcement techniques:
• clench teeth
• interlock and pull fingers

Question 23

What are the cutaneous stimulation reflexes?
Abdominal reflexes:
Plantar response:

Answer 23

• abdominal reflexes
• stroke in 4 quadrants of the abdomen towards the umbilicus
• normal response is movement of the umbilicus toward the stimulus fir to abdominal contraction

Plantar response:
-stimulate (scrape) the lateral aspect of the sole of the foot from the heel to curving medially across the ball of the foot
-normal response is plantar flexion of the hallux, recorded as plantar response is down going
Babinski sign= Dorsiflexion of the hallux (up going) ➡ indicative of a CNS lesion

Question 24

What is UMN vs LMN

View slides 34 and 35

Answer 24

 UMN = motor component of the CNS taking impulses from the relevant part of the brain to the synapses with the lower motor neurones.

 LMN = those neurones that connect with the target muscle. i.e. they run between the UMN synapse and the final action point.