Neurological Exam

Question 1

Chief Complaint

Answer 1

Attempt to get an accurate understanding of the chief complaint and each of the other associated symptoms, by using the following mnemonic: OPQRST

a. Onset: sudden is within minutes, gradual is over hours or days, very gradual is over months or years), and the progression and duration of each symptom.
b. Palliating/Provoking factors: what makes it better or worse
c. Quality or severity: describe, rate on a scale of 1-10
d. Radiation
e. Site – where is it, is it well-localised, diffuse
f. Timing – when does it start, how long does it last, how often does it come. Which part of the nervous system is involved – is it localised, involving a pathway, or non-specific.

The general format is:

1. Chief complaint: patient’s age, sex, presenting symptoms
2. History of the present illness
3. Past medical history
4. Review of systems
5. Family history
6. Social and environmental history
7. Medications and allergies

Question 2

1. Level of Arousal

Answer 2

Arousal

• The physiological and psychological state of being awake and reactive to stimuli
• Level of consciousness is very impaired in brainstem damage (reticular formation) and bilateral lesions of the cerebral hemispheres and thalamus. Toxic or metabolic factors can also impair consciousness. Impaired attention and cooperation can occur in many focal brain lesions, in dementia and encephalitis, and behavioural or mood disorders

Question 3

1.1 Level of Alterness

Answer 3

Glascow Coma Scale

• The GCS quantifies the level of consciousness typically following traumatic injury to the brain. It is most frequently used to assess head injury. The score ranges from 15-3. A score under 8 would apply to the unconscious patient. It is considered to be highly predictive of mortality.
• A decorticate posture indicates a lesion to the cerebral hemispheres, internal capsule or thalamus. The corticospinal pathways are interrupted, and this facilitates the rubrospinal pathways, resulting in a dystonia in which there is flexion of the upper limbs and extension in the lower limbs.
• A decerebrate posture indicates a lesion in the brainstem. All the limbs are extended, and the head and neck are arched. This indicates more serious damage to the CNS.

Question 4

2. Attention and Orientation

Answer 4

Test attention:

• Ask the patient to spell a short word forward and backward (“world”), name the months or give a short (6) string of numbers forward (6 or more e.g. 8-4-1-9-3-5) and backward (4 or more e.g. 9-7-2-3). Another test is serial 7’s in which the patient is asked to count back from 100 by 7’s. Impaired attention and cooperation can occur in many focal brain lesions, in dementia and encephalitis, and behavioural or mood disorders

Test Orientation:

• Ask for the patient’s name, address, the date and time (1 mark each). This shows the patient is aware of who he is, where he is and when it is. This requires memory, cognition and attention.

A&O×3 means alert and orientated to person, place and time

Question 5

3. Memory

Answer 5

Recent Memory

• Recent memory: ask the patient to recall 3 items or a brief story after a 5 minute delay. Make sure the patient has understood the information by asking her to repeat it immediately first.

Remote Memory

• ask the patient about past verifiable personal events
• Memory is the process of recording and retrieving information. The inability to register or recall something within a few seconds after it happens can also be due to impaired attention. Difficulty in recalling information after about 5 minutes usually indicates damage to the limbic system
• Loss of memory associated with a head trauma or concussion can cause loss of memory just after the incident (anterograde amnesia), and just before the incident (retrograde amnesia), but earlier memories are often intact.
  
  • Short-term memory covers events or memories that occurred minutes to days before
  • Long-term memory covers events or memories that occurred months to years before

Declarative/explicit memory

• Is retained in the bilateral medial temporal lobes and diencephalon is the conscious recollection of facts and experiences. Non-declarative or implicit memory is the recollection of unconscious skills or habit.

Question 6

4. Language

Answer 6

Spontaneous Speech

• ask a question about some aspect and note fluency, rate, abundance and note any errors or invented words.

To test comprehension

• Point to things e.g. the floor, and ask the patient to name them
• Ask the patient to point to named objects e.g. where is the door
• Give the patient a sentence, and ask him to repeat it e.g. “no if’s, and’s or

but’s”

Identify

• Hesitancies in speech (as seen in patients with aphasia from strokes)
• Monotone inflections (schizophrenia or severe depression)
• Circumlocutions: words or phrases are substituted for the word a person cannot remember; e.g., “the thing you block out your writing with” for an eraser
• Paraphasias: words are malformed (“I write with a den”), wrong (“I write with a branch”), or invented (“I write with a dar”)

Different kinds of language problems are caused by lesions in the dominant (usually left) frontal lobe, Broca’s area, left temporal and parietal lobes, Wernicke’s area, thalamus and caudate nucleus.

• Broca’s aphasia – expressive aphasia in which the subject has difficulty expressing himself, but understands the speech of others
• Wernicke’s aphasia – receptive aphasia in which the subject speaks in long sentences that make little sense, and include made up words.

Question 7

5. Calculations, Right-Left Confusion, Finger Agnosia, Agraphia

Answer 7

If all four are impaired in an otherwise intact person, this is called Gerstmann’s Syndrome, caused by lesions in the dominant parietal lobe, in the angular gyrus. Aphasia is often also present, which can make this difficult to test.

• Acalculia or inability to do calculations – simple addition, subtraction
• Right-left confusion – problem with identification of right and left body parts
• Finger Agnosia – problem with naming and identifying each digit. For example, touch your right ear with your left thumb.
• Agraphia – problems writing name or a sentence

If all 4 are strongly out of proportion to other cognitive functions, it usually indicates damage of the left (dominant) parietal lobe, but may indicate problems in the language, praxis, construction, logic and abstraction functions.

Question 8

6. Apraxia

Answer 8

Ask the patient to perform a task e.g. pretend to brush your teeth

Apraxia is an inability to follow motor commands that is not due to a primary motor deficit or language impairment. It is due to a problem in higher-order planning and conceptualisation of the motor task. The patient performs a task awkwardly and minimally despite having intact comprehension and motor function.

This can be caused by lesions in many different areas, and is common in language areas and adjacent structures in the dominant hemisphere.

Question 9

7. Neglect and Constructions

Answer 9

Hemineglect is an abnormality in the attention to one side of the universe not due to a primary sensory or motor disorder.

• Visual Neglect or extinction
  
  • Hold up fingers within the patient’s visual field on the right and the left sides, first upper and then lower quadrants. Wiggle the fingers on one side or the other, and sometimes on both sides. Instruct the patient to say on which side the fingers are moving. In visual hemineglect, the patient does not see the fingers on the affected side either when stimulated just on that side, or when double simultaneous stimulation is done (there will be extinction of the affected side).
• Tactile Neglect or Sensory neglect:
  
  • ask patient to close their eyes. Touch one area at a time, and ask the patient to point to where they were touched. Touch an area on both sides of the body at the same time and ask if the patient feels 1 spot or 2. They may ignore the affected side (usually left), but with double simultaneous tactile stimulation they will certainly ignore the affected side.
• Sensorimotor Neglect
  
  • Neglect Drawing Test: ask the patient to draw the face of a clock and all the numbers
  • Copy Drawing: ask the patient to copy a drawing you have made (simple geometric)

Hemineglect is most common in lesions of the right parietal lobe, causing neglect of the left side. It is less severe if the lesion is in the left hemisphere.

Question 10

8. Sequencing Tasks and Frontal Release Signs

Answer 10

Patients with frontal lobe dysfunction have difficulty changing from one action to the next.

• Manual alternating sequence task
  
  • If asked to draw triangles and squares, the patient gets stuck on one of the shapes and keeps drawing it. This is called perseveration. The Luria Manual Sequencing Task asks the patient to tap on the table with a fist, open palm and side of open hand and repeat the sequence quickly. These patients exhibit abulia i.e. very slow responses

Frontal lobe lesions cause the re-emergence of primitive reflexes, which is referred to as frontal release signs.

• Grasp reflex: forceful grasping of an object in contact with palm or sole
• Sucking reflex: a sucking response when the patient’s palate is touched (use earbud)
• Snout reflex: a pursing of the lips when the patient’s upper lip is tapped
• Palmomental reflex: an ipsilateral contraction of orbicularis oris and mentalis muscles when a stimulus is drawn up the thenar eminence to the base of the thumb.

Question 11

9. Logic and Abstraction

Answer 11

Analogies, logic: ask the patient to interpret proverbs like “don’t count your chickens before they hatch” or ask comprehension questions like “how are apples and oranges similar”.

The logic, coherence, and relevance of a patient’s thoughts as they lead to thoughts and goals; HOW people think. Abnormal functioning could indicate damage in many parts of the higher-order association cortex.

Question 12

10. Abnormal Thought Process

Answer 12

Note the presence of any of the following:

• Compulsions: repetitive behaviors that a person feels driven to perform to prevent or produce some future state of affairs
• Obsessions: recurrent, uncontrollable thoughts, images, or impulses that a patient considers unacceptable
• Phobias: persistent fear of a stimuli the patient feels is irrational (spiders, snakes, the dark)
• Anxiety: apprehension or fear that may be focused (phobia) or free floating (general sense of dread)
• Delusions: false, fixed beliefs that are not shared by other members of the person’s culture
• Delusion of persecution, grandeur, or jealousy
  
  • Delusion of reference: a person believes an outside event or object has an unusual personal reference to them; i.e., a comet passing earth means the patient should buy a car
  • Delusion of being controlled by outside forces
  • Somatic delusion: believing one has a disease or defect that he does not
  • Systematised delusion: a single delusion with many elaborations around a single theme all systematized into a complex network; i.e., the government is after the patient

Question 13

11. Mood

Answer 13

The affect is the observable mood of a person expressed through facial expression, body movements, and voice. Mood is the sustained emotion of the patient

• Euthymic: normal
• Dysthymic: depressed
• Manic: elated

Whilst often psychiatric in origin, imbalances may be due to toxic or metabolic abnormalities (e.g. hypothyroidism).

Question 14

Olfactory Nerve CNI

Answer 14

The test can be done with coffee and soap. Noxious odours will stimulate pain fibres (CN5) Impairment can be due to nasal obstruction, damage to olfactory nerves, or the olfactory bulbs. Patients with olfactory impairment usually complain of loss of taste.

Question 15

Optic Nerve CNII

• Function = Transmits special sensory information form the eye to the primary visual cortex of the brain (occipital lobe)

Answer 15

Opthalmascope examination

• Assess the eye for the following
  
  • Red light reflex (30cm away and 15 degrees lateral to patients line of vision)
  • Optic disc (yellow-orange or pink oval structure)
  • Shaprness of optic disc
  • Colour of disc
  • Size of central physiological cup
  • Insepct the retina: the arteries and veins extending from the disc, arteriovenous crossings, fovea, macula
  • Look for opactities in the virtreous humour

Visual Acuity

• Snellen Chart
  
  • Patient stands 6m or 20ft away from the chart and covers one eye and reads the lines of the chart. The number next to the line they can read is the second number of their vison e.g. 20/20 or 20/40

Colour Vision

• Ishihara charts
  
  • Red desaturation picks up differences in red colour perception and if acute can be associated with optic neuritis. The optic nerve is sensitive to red and if damaged, red objects appear faded. Ask the patient to look at something red alternatively with each eye and ask if they discern any relative dullness.
    • Optic neuritis can occur in MS, SLE, sarcoidosis, bacterial infections, herpes, measles

Visual Fields

• Stand directly in front of patient
• The patient must retain his gaze on the examiner’s pupils
• Ask patient to close one eye, and the examiner covers the eye on that side, in order to act as a control.
• Test each eye separately in the following way: Bring your index finger from the periphery into the patient’s field of view from above, below, laterally and medially for each eye field. The finger must be equidistant between you. You are using yourself as the control

Pupillary Light Reflex

• Tests the parasympathetic GVE of optic nerve and occulamotor nerve
• Direct response to light – pupil constriction
• Consensual response – the constriction of the opposite pupil
  
  • Swinging flashlight – swing the light from one side to the other with a 2-3s interval. The pupil of the eye with afferent pupillary defect dilates in response to the light (Marcus Gun pupil). This is because it will constrict consensually with the other eye, but is less sensitive to the direct light, which results in it dilating when the light swings across and directly into it.

Question 16

Oculamotor Nerve CNIII

• GSE Function = Motor innervation of extra-ocular muscles of the eye (Superior rectus, Inferior rectus, Lateral rectus, Medial rectus, Superior oblique, Inferior Oblique, Levator palpebrae)
• GVE Function = Parasympathetic supply of the pupillae (pupil constriction) and ciliary muscles (lens accommodation)

Answer 16

Convergence (GSE) and Accomodation (GVE)

• move a pen toward the patient and watch convergence of eyes. Ask the patient to tell you to stop when they can no longer focus on the pen.
• pupils constrict as an object moves closer to the eyes in order to cut down on the diverging rays of light entering the eye.
  
  • The patient should also be able to focus until close to the eyes. The lens is thickening due to ciliary muscle contraction, and this increases the refractive power of the lens i.e. it refracts the light more, which shortens the focal length.

Extra-occular Muscles (oculomotor, trochlear and abducens nerves)​

• Test each eye separately, and then the two together for conjugate movement
• Dysconjugate = deviation of one eye from the pther when looking att a abject
• The patient closes one eye, and is instructed to follow the movement of the clinician’s finger as it travels in a big H pattern to test each of the extraocular muscles of the eye and therefore also the nerves that supply them.
• Superior Rectus, Inferior Rectus, Inferior Oblique, Medial Rectus

Amblyopia = lazy eye

• if not corrected perminant vision loss can occur as the occipital lobe blocks the pathway to prevent two different incoming visual fields

Additional Eye Movements to Observe

• Saccades
• Optikinetic Nystagmus
• Doll’s eye (severly lathargic or comatose patients)

Question 17

Trigeminal Nerve CNIV

• Function = Innervation for Superior oblique muscle

Answer 17

• Extra-ocular muscles (down and out), Smooth Pursuit, Saccades, Optokinetic Nystagmus, Oculocephalic test

Question 18

Trigeminal Nerve CNV

• V1 Function = Sensory from cornea. Skin of forehead, scalp, eyelids, nose. Mucous membranes of nasal cavity and para-nasal sinuses
• V2 Function = Sensory of skin of maxilla, upper lip, upper row of teeth and gums. Mucous membrane of nose, maxillary sinuses, palate
• V3 Function = Sensory from skin of lower part of face and jaw, lower lip, lower teeth and gums, TMJ. Mucous membranes of mouth. Anterior 2/3 of tongue. Motor muscles of mastication (medial pterygoid, lateral pterygoid, masseter and temporalis). Anterior belly of digastric, tensor veli, palatine, tenor tympani.

Answer 18

Facial Sensation and Muscles of Mastication

• Sensory (GSA): Facial sensation – have the patient close his eyes, and lightly touch the face in the region of V1, V2 and V3, one side and then the other to compare. Have the patient saywhen and where he is touched, and are there any differences in the touch.
• Corneal reflex (CNV and CNVII) – have the patient look up, and lightly touch the cornea with a wisp of cotton wool. Note any asymmetrical blink response. Make sure the patient cannot see the approach, or the test will be for blink to threat.

Motor (SVE):

• Clench jaw and palpate the masseter and temporalis muscles.
• Keep jaw closed and resist opening.
• Keep jaw open and resist closing.

Reflexes

• Jaw jerk reflex. Place thumb just under lip and tap the chin at a downward angle while the mouth is held half open (use patella hammer). In a positive reflex, masseter muscles will jerk the mandible upwards quite forcibly – this is abnormal and indicates a hyperreflexia associated with lesions of the UMN pathways projecting to the trigeminal motor nucleus. Note that there is bilateral corticobulbar innervation to the trigeminal motor nucleus, so this response is quite rare. Both the afferent and efferent limbs of the jaw jerk are mediated by the trigeminal nerve.

Question 19

Abducens Nerve CNVI

• Function = Innervates lateral rectus muscle

Answer 19

• Neuro Exam = Extra-ocular muscles (H-Shape), Smooth Pursuit, Saccades, Optokinetic Nystagmus, Oculocephalic test

Question 20

Facial Nerve CNVII

• SVE Function = muscles of facial expression, stylohyoid, posterior belly of digastric muscle, stapedius in middle ear
• GVE Function = Innervates mucous glands of oral cavity, nose, pharynx, lacrimal gland. Innervates submandibular and sublingual salivary glands
• GSA Function = Sensory form external acoustic meatus
• SVA Function = Sensory taste of anterior 2/3 of tongue

Answer 20

Muscles of Facial Expression and Taste

• Facial muscles (SVE) – smile, wrinkle forehead (frontalis), close eyes tight and resist opening (orbicularis oculi), whistle, blow out cheeks (buccinators), show teeth (orbicularis oris), pull platysma muscles
• Taste (SVA) – anterior two thirds of the tongue

Note that upper motor lesions in the contralateral cortex or bulbar tracts causes contralateral facial weakness sparing the forehead (bilateral bulbar innervation), whilst lower motor lesions in the ipsilateral facial nerve nucleus, exiting nerve fibres, neuromuscular junction or face muscles causes weakness involving the whole ipsilateral face.

Question 21

Vestibulocholclear Nerve CNVIII

• Function = Sensory information form cochlea and vestibula apparatus to allow hearing and balance (equilibrium) SSA

Answer 21

Hearing and Vestibular Sense

• General testing: whisper into each ear while patient closes the other with a hand, and ask patient to repeat what was said. Or ask the patient to close his eyes and rub your fingers on one side or the other, and ask him to say on which side he hears the sound.

Otoscope or Auriscope Exam

• Assess the ear cannal and tympanic membrane for the follwing:
  
  • Signs of inflmmation
  • Shiny, pearly grey and tanslucent eardrum
  • Signs or bulge of retraction of the eardrum
  • Umbo
  • Cone of light
  • Manubrium of malleus
  • Perferarations of the membrane

Webber and Rinnie Test

• Holding the vibrating 512 Hz tuning fork in the centre of the forehead should result in equal sound appreciation picked up in both ears. In conductive hearing loss, the tone is louder in the affected ear. In sensorineural hearing loss, the tone is louder on the normal side.
• Holding the vibrating 512 Hz tuning fork first against the mastoid, and then near theexternal auditory meatus: conduction through air is normally better than through bone. In conductive hearing loss this is reversed. In sensorineural hearing loss it is not reversed, but hearing is decreased in the affected ear.

Vestibular Sense

• Dix-Hall Pike positional testing: the patient’s head is held 45 ̊ to one side, and is then supported from a sitting to a lying position rapidly, the head held 30 ̊ below the horizontal for 20s. The eyes are observed for any nystagmus. The patient is asked to report any vertigo. Once the symptoms have cleared, the patient is supported into a sitting position again very rapidly, and the same symptoms are observed. Normally there should not be any vertigo or nystagmus. The change in position as the patient lies back maximally stimulates the posterior semicircular canal of the ear that is down, and the anterior semicircular canal of the ear that is up.
• The importance of this test is in its ability to determine whether the vertigo is central or peripheral:
  • In a peripheral lesion, there is delayed onset of nystagmus and vertigo. The nystagmus is horizontal and fades in under 30s. The vertigo diminishes if the test is repeated (adaptation)
  • In a central lesion, the nystagmus and vertigo starts immediately, there is no adaptation and the nystagmus can be horizontal or vertigo and can change direction.
• Fukuda Step test: the patient is asked to close his eyes, extend his arms in front of him and step quite vigorously on the spot for a minute. A lateral rotation greater than 45° can indicate unilateral vestibular dysfunction, with a turn toward the affected/weaker side. The sensitivity and specificity of this test is poor
• Oculocepahlic Testing

Question 22

Glossopharangeal Nerve CNIX

• SVA Function = Sense of taste from posterior 1/3 of tongue
• GSA Function = Sensory from mucosa of palatine tonsil and oropharynx, posterior 1/3 of tongue, auditory tube, middle ear
• GVA Function = Sensory from carotid body and sinus
• GVE Function = Parasympathetic innervation of parotid salivary gland
• SVE Function = Innervates Stylopharyngeus muscle

Answer 22

Palate Elvation and Gag Reflex

• CNX: Say “Ahh” – hold down the tongue with a tongue depressor and observe any asymmetry in palatal movement. The uvula deviates away from the side of palatal weakness.
• Gag reflex – gently touch soft palate and pharynx (the afferent pathway is via the CNIX and the efferent is via CNX). Note any asymmetry in contraction of the palate
• Dysphagia (impaired swallowing) may be due to lesions of CNIX, X, XII, NMJ, corticobulbar pathways, or a local soft tissue lesion e.g. an oesophageal stricture or neoplasm

Articulation

• Voice and cough – any hoarseness in the cough or the voice (dysphonia)

The lesion can be in the muscles of articulation, the vocal cords themselves, the neuromuscular junction, or the described nerves. The voice that has recently changed is most significant. Abnormal speech can also be due to lesions in the motor cortex, cerebellum or basal ganglia.

• Dysarthria – abnormal articulation of speech can be due to problems with CNV, VII, IX, X, XII or the NMJ, muscles of articulation, motor cortex, cerebellum, basal ganglia or corticobulbar tracts. As the patient to repeat “pa, pa, pa, pa”, “ta, ta, ta, ta”, “ga, ga, ga, ga”.
• Aphasia (problems with the expression and/or understanding of language) is usually a higher order cognitive function abnormality that affects language formulation or comprehension

Question 23

Vagus Nerve CNX

• SVE Function = Constrictor muscles of the pharynx (except stylopharyngeus), Intrinsic muscles of larynx Muscles of palate (except tensor veli palatini), Striated muscle in upper 2/3 of oesophagus
• GVE Function = Cardiac muscle Smooth muscle of airways and digestive tract
• GSA Function = Sensory from auricle, external auditory meatus, and dura mata in posterior cranial fossa
• GVA Function = Sensation from base of tongue, pharynx, larynx, airways, heart, oesophagus, stomach and intestine (as far as left colic flexure)
• SVA Function = Taste from epiglottis and palate

Answer 23

• Neuro Exam = Say Ahh Test, Gag reflex, Articulation test (“pa, pa, pa, pa”, “ta, ta, ta, ta”, “ga, ga, ga, ga”.

Question 24

Accessory Nerve CNXI

• Function = Innervation of Sternomastoid and Trapezius

Answer 24

The accessory nerve supplies the sternocleidomastoid and trapezius muscles, which have the following functions:

• Rotation of head away from the side of the contracting sternocleidomastoid muscle.
• Tilting of the head toward the contracting sternocleidomastoid muscle.
• Flexion of the neck by both sternocleidomastoid muscles.
• Elevation of the shoulders by the trapezius.

Technique

• Observe the volume and contour of the sternocleidomastoid muscles as the patient looks ahead.
• Test the right sternocleidomastoid muscle by facing the patient and placing your right palm laterally on the patient’s left cheek. Ask the patient to turn the head to the left, resisting the pressure you are exerting in the opposite direction. At the same time, observe and palpate the right sternocleidomastoid with your left hand. Then reverse the procedure to test the left sternocleidomastoid.
• Have the patient tilt the head toward the left shoulder, and palpate the sternomastoid on the left. Repeat on the right.
• Place your hand on the patient’s forehead and push backward as the patient pushes forward. Observe and palpate both sternocleidomastoid muscles.

Now test the trapezius

• Have the patient face away from you and observe the shoulder contour for hollowing, displacement, or winging of the scapula. Observe for drooping of the shoulder. Ask the patient to shrug the shoulders and hold for about 5s, then apply a force in the opposite direction and have the patient resist the force.

Clinical Significance

• Supranuclear (corticobulbar) lesions of the eleventh nerve cause moderate, often transient, impairment of function of the sternocleidomastoid and trapezius muscles. Note that the corticobulbar supply to sternomastoid is ipsilateral, and to trapezius is contralateral.
• Isolated lesions of the spinal accessory nerve are rare. Surgical injury is one cause

Question 25

Hypoglossal Nerve CNXII

• Function = Innervation of the muscles of the tongue

Answer 25

Tongue Muscles

• Observe the tongue in the mouth first: look for atrophy or fasciculations – sign of lower motor neuron lesions
• Ask patient to protrude the tongue: unilateral tongue weaknesses cause the tongue to deviate to the weak side
• Ask patient to place tongue in cheek and observe muscle strength or power of the tongue

Question 26

Motor Exam Spasticity and Rigidity

Answer 26

Motor Exam includes the following:

• Observation for twitches, tremours, fasiculations, involuntary movments, posture and general patient position
• Inspection for muscle waisting, hypertrophy, fasiculations (intrinsic hands muscles, shoulder girdle, thigh)
• Palpation to detect any tenderness (myositis)
• Muscle tone testing
  
  • Upper Extremity Tone
    • Simultaneously grasp the elbow and take the hand as if to shake it. Pronate and supinate the forearm, then roll the hand at the wrist. Compare right with left.
    • Fast elbow test: hold hand and support elbow in the flexed position. The rapidly extend the elbow and observe the resistance.
  • Lower Extremity Tone
    
    • With the patient lying down and the legs extended, suddenly lift the lower limb up at the knee. The heel should drag against the surface of the bed when the tone is normal.
    • Flex the hip and knee, and take the hip, knee and ankle through their ROM
    • Contact the thigh and roll the leg inward and outward, noting the lag in the foot relative to the upper leg. Increased resistance will result in the whole leg rolling as one entity.
  • Test for Clonus
    
    • Upper limb: have the patient in a relaxed position with the elbow slightly flexed. Contact palm on palm and extend the elbow and then apply a high velocity, short amplitude thrust that further extends the wrist, and look for any resulting clonus as a repetitive jerking flexion and extension against your hand.
    • Lower limb: have the patient supine, with knee extended. Support the ankle and whilst holding the plantar aspect of the forefoot, extend the ankle into dorsiflexion. Apply a high velocity, short amplitude thrust further dorsiflexing the ankle, and look for any signs of clonus as above.

Modified Ashworth Scale for Spastic Tone

0 - No increase in muscle tone (should be no resistance to the movement)

1 - Slight increase in muscle tone, manifested by a catch and release or by minimal resistance at the end of the range of motion when the affected part(s) is moved in flexion or extension

1+ - Slight increase in muscle tone, manifested by a catch, followed by minimal resistance throughout the remainder (less than half) of the ROM

2 - More marked increase in muscle tone through most of the ROM, but affected part(s) easily moved

3 - Considerable increase in muscle tone, passive movement difficult

4 - Affected part(s) rigid in flexion or extension

• Hypertonia can be divided into spasticity and rigidity.
  
  • Spasticity is due to an UMN lesion, and is typically clasp-knife in its effect (when closing a Swiss army knife for example, it is first very resistant and then gives way as it snaps shut).
• Rigidity however often accompanies basal ganglia disease and the resistance is not dependent on the rate or force of the movement and is constant throughout the range of motion and is typically lead-pipe in its effect.

Question 27

Motor Exam Functional Test

Answer 27

Functional Test

Functional testing is done before formal muscle strength testing to detect subtle abnormalities.

• Drift: ask the patient to hold up both arms with palms facing up, at the horizontal level, hold the position and close his eyes. Ask him to shake his head “no” while maintaining this position. Note any drifting of the arms. There are 3 causes for drift of the arm:
  
  • Cerebellar disease: drift is upwards, and includes slow pronation of wrist and elbow.
  • Loss of proprioception: the drift is a searching movement and usually affects the fingers only. It is due to loss of joint position sense and can be in any direction.
  • UMN/pyramidal weakness: the drift is due to muscle weakness and tends to be in a downward direction. The drifting starts distally in the fingers and proceeds proximally. There may be a slow pronation of the wrist and flexion of the fingers and elbow. This could indicate subtle spasticity because corticospinal damage tends to spare the flexors relative to the extensors and the pronators relative to the supinators. So the pronator muscles have a higher tone and tend to cause this pronation to occur.
• Fine movements - rapid hand movements shows up weaknesses, tone abnormalities, tremours, co-ordination problems. Compare the right with the left.
  
  • Tap the thumb and index finger together rapidly on left and right
  • Pretend to screw in a light bulb - pronation-supination rapidly at the wrist
  • Tap the hand rapidly against the thigh on right and left
  • With the heel on the ground, tap the toes rapidly on the ground on the left and right.

Question 28

Motor Exam Muscle Testing

Answer 28

Patterns of weakness can localise a lesion to a cortical region, spinal cord level, nerve root, peripheral nerve or muscle. Test the muscles in pairs to note any asymmetries. Ascertain the level of the weakness.

Medical Research Council Muscle Strength Scale

• 0/5: no contraction
• 1/5: muscle flicker, but no movement
• 2/5: movement possible but not against gravity (test the joint on its horizontal plane)
• 3/5: movement possible against gravity, but not against resistance by the examiner
• 4/5: movement possible against some resistance by the examiner
• 5/5: normal strength

The muscles innervated by a single nerve root constitute a myotome.
Do not put the patient into the muscle testing positions. Rather tell them or show them on your own body. This is to ascertain whether the patient is a 1 -3/5. If the patient can get into that position, have the patient hold the position against gravity and count to five. This establishes a 3/5. Then have the patient hold the position and resist your force in the other direction. This is to establish a 4-5/5.

C1-T1 Nerve Root Myotome Tests

• C1-2: neck flexion
• C3: lateral neck
• C4: Shoulder elevation
• C5: shoulder abduction
• C6: elbow flexion full supination C6: wrist extension
• C7: elbow extension
• C7: wrist flexion and finger extension
• C8: finger flexion
• T1: finger abduction

L1 to S1 Nerve Root Myotome Tests

Sitting

• L1-2: hip flexion
• L2-3: hip adduction
• L4/5: hip abduction
• L3: knee extension
• L4: foot inversion
• L4-5: ankle dorsiflexion
• L5: big toe extension
• S1: foot eversion

Prone

• L5/S1: hip extension
• L5/S1: knee flexion
• S1: foot plantar flexion
• S2: toe flexors

Question 29

Sensory Exam Dermatomes

Answer 29

Comparisons should be made from one side to the other, and from proximal to distal. Note if there is a specific spinal segment level below which sensory perception abruptly changes, as this could indicate a spinal cord lesion requiring emergency attention. The pattern of sensory loss can help to localise the lesion to a particular nerve, nerve root, region of the spinal cord, brainstem, thalamus or cortex. Usually loss of vibration sense, joint position sense and temperature are not reported as symptoms, but loss of light touch and pin prick sensation is.

Primary Sensation

• Fine discriminatory touch, vibration and conscious position sense: posterior columns (Blunt end of the Neurotip)
• Crude touch, pain and temperature: anterolateral tracts (Sharp end of Neurotip)

Question 30

Sensory Exam Cortical

Answer 30

Cortical: The ability of the sensory cortex to analyse and interpret sensations

• Stereognosis: place a key or familiar object in the patient’s hand and ask the patient to identify it
• Number identification (graphaesthesia): outline a large number in the patient’s palm and ask the patient to identify the number
• Two-point discrimination: Use a bent paper clip and alternate randomly between touching the patient with one or both points. Note the minimum separation of the points that the patient can discern, and compare at each extremity on both sides.
  
  • 2-4mm: lips, finger pads 8-15mm: palm 30-40mm: shins, back
• Point localisation: lightly touch a point on the patient’s skin and ask the patient to point to that spot

Question 31

Sensory Exam Proprioceptive sensation

Answer 31

Joint Position Sense

• Tell the patient that you will place her limb in a particular position with her eyes closed, and then return it to a neutral position. She will then need to mimic that movement with the same limb and with the other limb.
• With the patient’s eyes closed, move his forefinger to different positions, and have him touch his forefinger with the other forefinger.
• With the patient’s eyes closed, have him place his forefinger on the tip of his nose.

Passive Movement

• Tell the patient to close her eyes, and hold the thumb or finger on the medial and lateral side. Move the phalanx up and down and ask her if it is moving, and in which direction. If an error is made, repeat the test until 6 successive correct answers are given, or until the defect is firmly established. Move from distal to more proximal joints

Vibration sense

• A 128Hz or 256Hz tuning fork is set to vibrate and placed on the clavicle of the patient (eyes open). He is asked if he feels it, what he is feeling and when it stops
• The patient then closes the eyes. The vibration is applied at the shoulder tip, elbow, radial bone near the base of the thumb and on the pulp of the index finger. In the lower limb, it is applied to the ASIS, medial knee, medial maleolus of the ankle and the pulp of the big toe. The two sides are compared.

Question 32

Neurological Examination of the Trunk

Answer 32

• Sensory: light touch and pain
• Motor: Beevor’s sign: movement of the umbilicus upwards or superiorly when the neck is flexed or the patient is asked to sit up. This indicates weakness in the lower abdominal muscles. When sitting up, the upper abdominals are contracting normally, but not the lower, and the result is that the umbilicus is pulled upwards.