Week 6: The Nervous System Flashcards
Taking a case history- review of systems?
What questions do we ask?
- any seizures or loss of consciousness
- any episodes of dizziness or vertigo
- any difficult with or slurred speech?
- any recent difficulty with memory
What are the four components to the Neurological Exam?
- Cranial nerves
- Motor
- Sensory
- Balance, co-ordination and gait
Checking there mental state:
A few questions to ask?
- what is your name
- where are you?
- what is the day?
Get the opinion of the nearest relative/ carer too
What do you observe for a nervous system examination?
-level of consciousness
-asymmetry (motor exam)
-gait (gait, balance and co-ordination)
Symmetry is the key so comparison with the other side is essential
CN 1: olfactory
Cranial nerve examination
View page 326 for more info on testing these cranial nerves in bates guide to physical examination
-test latency of nostrils first
-testing sense of smell (olfaction)
More common causes of abnormal function: sinus, head trauma, smoking, frontal lobe tumour.
CN 2: Optic
Visual acuity
- smelled chart (centra vision)
- visual field by confrontation (peripheral vision)
Opthalmoscopy Papilloedema: Causes: -raised ICP- causes -option nerve disease -optic neuritis
CN 2 and 3: optic and oculomotor
- pupillary inspection
- pupillary reactions to light
- If reactions to light are abnormal, test near response.
CN 3, 4 and 5: oculomotor, troachlear and abductees
- inspect for Ptosis
- test extraocular movements
- test for convergence
CN 5: trigeminal
What is trigeminal Neuralgia?
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
CN 7: facial
What are some common causes of facial nerve lesions?
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.
CN 8: vestibulocochlear
What do you test?
How do problems come about?
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
CN 9 and 10: glossopharyngeal and vagus
- 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
CN 11: spinal accessory
Observe trapezius posteriorly for atrophy/ fasciculations Test trapezius strength: -shoulder shrug against resistance Test SCM strength: -push into hand, testing opposite SCM
CN 12: hypoglossal
-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
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
31 pairs of spinal nerves from the spinal cord:
-8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal
Examination of the motor system.
What do you inspect?
What do you assess?
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
Learn the different Myotomes on slide 8 and 9
Yep
Muscle strength: grading
- 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)
Muscle strength: terminology
Partial loss =?
Complete loss= ?
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 )
Memorise the deep tendon reflexes On slide 15 Biceps - nerve root level? Supinator/ brachioradialis Triceps Patellar Achilles Medial hamstring Lateral hamstring
Ye
Grading of reflexes
What do each of these numbers mean?
0, 1+, 2+, 3+, 4+
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)
Clonus tested on the ankle. How do you do it?
- 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
DTR’s: Reinforcement
When do you use this technique?
- if DTR’s are symmetrically diminished or absent, use either of the 2 common reinforcement techniques:
- clench teeth
- interlock and pull fingers
What are the cutaneous stimulation reflexes?
Abdominal reflexes:
Plantar response:
- 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
