Makindo Medical Notes.com

Related Subjects: |Cortical functions |Motor System |Sensory System |Mental state Examination |Speech and Language Exam |Cranial nerves and examination |Assessing Cognition

Localising Neurology - Pattern of Weakness

• Same side face,arm,leg: Intracranial lesion - tumour , stroke, MS
• Same side arm,leg, opposite side face: Brainstem - tumour , stroke, MS
• Same side arm,leg : Intracranial or cervical
• Both arms and legs weak and face spared: Cervical cor

Cranial Nerves

• CN I: Olfactory
  • Test each nostril in turn with orange peel or coffee, vanilla, peppermint. Do not use smelling salts as these can stimulate V nerve.
  • Impaired
    • ENT disease
    • COVID
    • Frontal meningioma
    • Frontal tumour
    • Parkinson’s disease
• CN II: Optic nerve (covered elsewhere)
  • Visual acuity
  • Correct refraction with glasses or pinhole
  • Assess with Snellen chart
  • Quick Bedside test - use Newspaper print at 30 cms
  • Cover one eye and test each in turn
    • Reads small print
    • Reads Medium print
    • Reads Headlines
    • Can Finger count
    • Can detect hand wave
    • Can detect light
  • Visual fields by confrontation
    Bitemporal hemianopia
    • Pituitary macroadenoma (upper defect > Lower)
    • Craniopharyngioma (Lower defect > Upper)
    • Homonymous Hemianopia
      • Contralateral Stroke
      • Contralateral Tumour
    • Homonymous Quandrantopia
      • Upper: Contralateral Temporal lobe pathology e.g. stroke, tumour
      • Lower: Contralateral Parietal lobe pathology e.g. stroke, tumour
  • Examining Pupils
  • Large: mydriasis (symp (Adrenaline/Anticholinergics)>para)
    • IIIrd nerve palsy (pupil also down and out and ptosis)
    • Evening time or dark
    • Atropine (Belladonna)
    • Ipratropium (Anticholinergic)
  • Small: Miosis (para (Acetyl choline) > symp)
    • Senile miosis
    • Opiates (With coma consider Naloxone)
    • Horner's syndrome
    • Pontine strokes
    • Organophosphates
    • Cluster headache
  • Pupil response to light: shine light right eye and inspect both then other eye
    • Both pupils should constrict when light in one eye
    • Absent direct and consensual : blind eye
  • Pupil response to accommodation
  • Eyes should adduct and pupils miose to look at close objects
  • Classical Pupils
    • Marcus-Gunn pupil A deafferented pupil which constricts to consensual but notto direct light Absent CN II
    • Hutchinson pupil A dilated pupil that does not respond to direct or consensual light Present CN III
    • Horner's syndrome A small pupil with associated ipsilateral ptosis and decreased facial sweating Present Sympathetic
    • Adie's tonic pupil A dilated pupil with an impaired light response and slow constriction to near vision Present Parasympathetics
    • Argyll Robertson pupil A small, irregular pupil that constricts to near vision but notto light usually due to neurosyphilis
  • Ophthalmoscopy
  : look at retina
  • Optic atrophy: Blind eye Pale disc represents head of myelinated optic nerve with 1.2 M axons
    • Causes are
      • Compressive – secondary to papilledema, tumour, bony growth (fibrous dysplasia, osteopetrosis), thyroid eye disease, chiasmal (pituitary etc), optic nerve sheath meningioma, disc drusen, increased intraocular pressure (glaucoma)
      • Vascular – arteritic and non-arteritic ischaemic optic neuropathy, diabetes,
      • Inflammatory – sarcoid, systemic lupus, Behcet’s, demyelination (MS), etc.
      • Infectious – viral, bacterial, fungal infections - herpes, TB, bartonella, etc.
      • Toxic & nutritional – many medications such as ethambutol, amiodarone, methanol, vitamin deficiency etc.
      • Metabolic – diabetes
      • Neoplastic – lymphoma, leukaemia, tumour, glioma
      • Genetic – Autosomal dominant optic atrophy (OPA1), Leber’s hereditary optic atrophy, Leber's hereditary optic neuropathy, as a late complication of retinal degeneration.
      • Radiation optic neuropathy
      • Traumatic optic neuropathy
    • Diabetic Changes
      • Cataracts
      • Non proliferative diabetic retinopathy
      • Proliferative diabetic retinopathy
  • Ptosis (Tests IIIrd nerve + sympathetic to Mullers muscle)
    • Unilateral mild ptosis and small pupil: Horner's syndrome
    • Bilateral Ptosis and frontal balding: myotonic dystrophy.
    • Partial to complete ptosis and pupil down and out is IIIrd nerve palsy
  • CN III, IV, VI: Oculomotor, Trochlear, Abducens are best examined all together as movements of the eye and pupil and eye opening
    • Anatomy: There are 6 extraocular muscles + mullers muscle to eye lid
      • Oculomotor nucleus: dorsal midbrain close to midline at level of superior colliculus to innervate ipsilateral Medial rectus, Superior Rectus, Inferior Rectus, Inferior oblique
      • Trochlear nucleus: dorsal midbrain close to midline at level of inferior colliculus and nerve crosses over to innervate superior oblique
      • Abducent neve: Dorsal Pons close to ipsilateral VII to ipsilateral lateral rectus
    • Clinical
      • Lid retraction and Exophthalmos
        • Thyroid eye disease
        • Retroorbital tumour
      • Look at pupils: shape, relative size, ptosis.
      • Shine light in from the side to gauge pupil's light reaction.
      • Assess both direct and consensual responses.
      • Assess afferent pupillary defect by moving light in arc from pupil to pupil.
      • Follow hand with eyes – placing a hand on head usually stops head moving. Do an H pattern.
      • Look for failure of the movement, nystagmus [pause to check it during upward/ lateral gaze] and ask about diplopia
      • Convergence by moving finger towards the bridge of pt's nose.
      • Test accommodation by pt looking into the distance, then a finger 10cm from the nose.
  • CN V: Trigeminal: Largest of the cranial nerves. Several brainstem nuclei.
    • Anatomy: Most of nerve in Pons but facials sensory dips down to medulla in onion like layers
      • Ophthalmic Branch
      • Maxillary Branch
      • Mandibular branch
    • Sensory
      • Cornea and tip of nose (see Hutchinsons sign)
      • Face and scalp as far back as vertex
      • Lower face with Gums, teeth, cornea, sinuses
    • Testing
      • Examination: Corneal reflex: patient looks up and away as you touch the cornea with a wisp of cotton wool. Look for afferent blink (VII) reflex in both eyes, ask if could feel it.
      • Facial sensation: sterile sharp item on forehead, cheek, jaw. The occiput and angle of jaw are supplied by C2. Repeat with a dull object. Ask to report sharp or dull. If abnormal, then temperature [heated/ water-cooled tuning fork], light touch
    • Motor nerve
      • Muscles of mastication the temporalis, masseter, and lateral and medial pterygoid muscles. Innervated by the mandibular branch
    • Testing
      • Motor: pt opens mouth, clenches teeth (pterygoids). Palpate temporal, masseter muscles as they clench.
      • Test jaw jerk: Finger on tip of the jaw. Grip patellar hammer halfway up shaft and tap finger lightly. Usually, nothing happens, or just a slight closure. If increased closure, think UMN Lesion e.g. pseudobulbar palsy.
    • Trigeminal lesions seen with
      • Brainstem vascular disease
      • Posterior fossa tumour s
      • Herpes simplex and zoster infections
      • MS can cause neuralgia, Trigeminal neuralgia dealt with later on
  • CN VII: Facial
    • Anatomy
      • Nucleus lies in the pons close to midline and IVth ventricle
      • Close to the nucleus of the VI
    • Clinical
      • Inspect for facial droop at edge of mouth and flattening
      • Ask patient to close eye and either slowed on affected side unable to close
      • Look for Loss of nasolabial fold on the affected side.
      • As patient attempts to close eye the globe elevates (Bell's sign).
      • Ask patient to raise eyebrows and wrinkle forehead. Unable when LMN lesion but can with stroke
      • Ask patient to whistle, puff cheeks. Close mouth and try to move lips apart.
    • Findings
      • Unilateral facial weakness
        • Upper and Lower face weak (LMN)
          • Bells palsy
          • Parotid tumour
          • Herpes Zoster (Ramsay Hunt syndrome with vesicles in outer ear)
        • Lower face weak but eye closure fine UMN - Ipsilateral Stroke or SOL
      • Bilateral facial weakness
        • LMN:
          • Guilllain Barre syndrome
          • Botulism
          • Myasthenia Gravis
          • Lyme disease
          • Bilateral Parotid tumour s
          • Sarcoid
        • UMN
          • Bilateral Strokes or SOL
          • Listerial rhombencephalitis
          • CNS tuberculosis, sarcoidosis
  • CN VIII: Vestibulocochlear
    • Anatomy: Nucleus in the Pons
    • Basics : Does Hearing (Cochlear) and Balance (Vestibular)
    • Clinical
      • Inspect: Hearing aids or other tools for the heard of hearing. if indicated, look at external auditory canals, eardrums.
      • Test Hearing: Rub one hand's fingers with noise on one side, another hand noiselessly. Ask pt. which ear they hear you rubbing. Repeat with louder intensity, watching for abnormality.
      • Weber's test: Lateralization. 512/ 1024 Hz [256 if deaf] vibrating fork on top of patients head/ forehead. "Where do you hear sound coming from?" Normal reply is midline.
      • Rinne's test: Air vs. Bone Conduction: 512/ 1024 Hz [256 if deaf] vibrating fork on mastoid behind the ear. Ask when stop hearing it. When stop hearing it, move to the patients ear so can hear it. Normal: air conduction [ear] better than bone conduction [mastoid].
  • CN IX, X: Glossopharyngeal, Vagus
    • Anatomy: Nuclei Lie in the lateral medulla
    • Clinical
      • Examination Voice: hoarse or nasal. Pt. swallows, coughs (bovine cough: recurrent laryngeal). >
      • Examine palate for uvular displacement. (unilateral lesion: uvula drawn to normal side).
      • Pt says "Ah": symmetrical soft palate movement.
      • Gag reflex [sensory IX, motor X]: Stimulate back of throat each side. Normal to gag each time.
  • CN XI: Accessory
    • Anatomy: Lies in the medulla
    • Innervates Trapezius and Sternocleidomastoid
    • Clinical
      • Inspect for muscle wasting and fasciculations
      • Pt. shrugs shoulders (Trapezius).
      • Pt. turns head against resistance: watch, palpate SCM on the opposite side.
    • Pathology
      • Neck tumour or neck dissection
  • CN XII: Hypoglossal
    • Anatomy: Lies in the medial ventral medulla
    • Examination: Inspect tongue in mouth for wasting, fasciculation. Listen to articulation. Assess eating. Protrude tongue: unilateral deviates to the affected side
    • Motor: Innervates all intrinsic and almost all extrinsic muscles of the tongue, as well as one suprahyoid muscle, the geniohyoid muscle.
    • Sensory: sensory fibers through many of its synaptic relations with the solitary nucleus and the sensory nuclei of the trigeminal nerve (CN V). It is included in reflex movements of the tongue such as swallowing or chewing.
    • Lesions
      • UMN: spastic stiff tongue
        • Strokes
        • Pseudobulbar palsy
        • MS
        • MND/ALS
      • LMN: wasted fasciculating tongue
        • MND/ALS
        • Polio

  Upper Limb Neurology

  • Weakness: MRC scale
    • 0 No contraction
    • 1 Flicker of contraction
    • 2 Active movement no gravity
    • 3 Active movement against gravity
    • 4 Active movement against gravity and resistance
    • 5 Normal power
    • some add + or -
  • LMN : lesion is distal to the anterior horn cell.
    • Weakness
    • Reduced or absent reflexes
    • No movement or Down going plantar
    • Muscle wasting and fasciculations. The
  • Deep tendon reflexes:
    • 0 = absent
    • 1 = diminished
    • 2 =normal
    • 3 = brisk
    • 4 = hyperactive clonus
  • UMN: The lesion is between motor cortex and anterior horn cell.
    • Hyperreflexia
    • Extensor (upgoing) plantar
    • Increased tone
    • Clonus

Upper limb

• Inspection
  • Look at the limb the upper and lower surface
  • Looking for wasting, scars and fasciculations.
  • Feel muscle bulk e.g quads and compare each side and look for wasting.
  • Consider measuring thigh circumference.
  • Are they tender or fasciculating or wasted
• Motor
  • Pronator drift: Ask the patient to hold arms out straight ahead horizontally with palms up and close eyes. If the affected side slowly pronates and the elbow flexes and drifts down is a subtle sign of an UMN lesion on that side

  Assessment of Tone

  • Assess upper limb tone in the wrist and elbow. Get the patient to relax and distract with irregular movements. Different types of altered tone associated with disease
  • Spasticity - increased tone seen with pyramidal weakness classically is variable with velocity and distance joint moved. High tone often gives way and has been called "clasp knife". Best seen in forearm supination in the upper limb and knee flexion in the lower limb.
  • Extrapyramidal disease gives a more constant increase in tone through all movements and is called "lead pipe" rigidity. Seen classically with Parkinson's disease. If there is a superimposed tremor the increased tone may be called "cogwheel"
  • Gegenhaltan - an erratic increase in tone in those with frontal lobe dysfunction also called "paratonia"

  Power - Upper limb

  • Shoulder abduction before 90 degrees is supraspinatus muscle and suprascapular nerve and C5 root
  • Shoulder abduction beyond 90 degrees is deltoid supplied by axillary nerve C5
  • Shoulder adduction is by multiple muscles/nerves and generally C7 root and adds little
  • Shoulder external rotation is by infraspinatus and suprascapular nerve and C5 root
  • Shoulder internal rotation is subscapularis muscle and subscapular nerve and C5 root
  • Elbow flexion biceps muscle and Musculocutaneous nerve and C6 and some C5 roots
  • Elbow flexion half pronated (holding a cup) is radial nerve supply to brachioradialis and is most C6 and some C5
  • Elbow extension is by triceps supplied by radial nerve and C7 root
  • Wrist flexion flexor carpi radialis (Median) Flexor carpi ulnaris (ulnar) and C7/8 roots
  • Wrist extension extensor carpi radialis longus and external carpi and ulnaris radial nerve/posterior interosseous C7
  • Finger flexion: Median and Ulnar nerves to long and short flexors
  • Finger extension: extensor digitorum Posterior interosseous nerve (radial) C7
  • Finger abduction: Ulnar nerve (dorsal interossei) T1 (DAB)
  • Finger adduction: Ulnar nerve (palmar interossei) T1 (PAD)
  • Thumb opposition: Opponens pollicis Median nerve T1
  • Thumb flexion: Flexor pollicis brevis Median nerve T1
  • Thumb adduction: Adductor pollicis T1

  Individual nerves - Motor

  • Median nerve: Opponens pollicis Abduction and opposition of thumb and thumb flexion and T1 nerve root
  • Ulnar nerve: Flexion of the ring and little finger (medial two lumbricals) and adduction and abduction of fingers (dorsal interossei) and thumb adduction T1
  • Radial nerve: "Wrist drop" Wrist extension by long and short extensors C8

  Palpating Nerves : Enlarged nerves

  • Leprosy - is mainly sensory enlarged ulnar and radial and ulnar and others
  • Hereditary neuropathies e.g. Charcot Marie Tooth disease - mainly motor
  • Neurofibromatosis
  • Refsum's disease - phytanic acid deficiency, autosomal recessive
  • Amyloidosis

Reflexes - Tests the integrity of the normal reflex arc and the effect of higher centres on it

• Biceps C5(6)
• Supinator C(5)6
• Triceps C6/7
• Hoffman reflex is hyperreflexia - flick DIP of the index finger and thumb adducts
• Record as -,+,++,+++

Coordination

• Finger-Nose - test for coordination: Touch tip of the nose and then my finger, eyes open. Examiners should move their finger around as a moving target. Ask the patient to touch nose with eyes closed to assess proprioceptive deficit as a cause of ataxia
• Rapid movements: Touch left palm with the right palm and then supinate right hand to touch left palm with dorsum of the right hand. Alternative quickly and then switch sides. Difficulty called dysdiadochokinesia and is a sign of cerebellar disease
• Increased suggests a loss of inhibition from higher pathways with an Upper motor lesion
• Be able to draw a reflex arc with afferent and efferent pathways
• Absence suggests a lower motor neurone lesion e.g. neuropathy such as Guillain-Barré syndrome
• Absent reflexes: Neuropathy e.g. GBS, nerve compression, disease of the neuromuscular junction, Myopathy

Lower limb Inspection

• look for deformity, scars, wasting, fasciculations
• Pick up leg asking first to check if it is not painful and look at heel for ulcers and sole of feet
• Look for neuropathic or vascular or ulcers or Charcot's joint deformity, inverse champagne bottle legs (CMT)

Tone / Clonus

• Assess tone by first rolling the leg and then a sudden lift up at the knee and see if the ankle comes off the bed.
• Could suggest increased tone and a UMN lesion.
• Get a feel for tone at ankle and knee and don't forget to test for clonus either now or after having demonstrated increased reflexes

Power - lower limb

• Hip flexion Femoral nerve Iliopsoas: "Pull knee up" L1/2 roots
• Hip extension: Gluteus maximus Inferior gluteal nerve "Force thigh down onto bed" L5/S1 roots
• Knee flexion: L5/S1 hamstrings Sciatic nerve "bend knee"
• Knee extension: L3/4 Femoral nerve quadriceps "straighten knee"
• Ankle plantar flexion: S1 sciatic gastrocnemius" push foot down"
• Ankle dorsiflexion: L4/5 Sciatic via common peroneal nerve. Tibialis anterior "pull foot up"
• Toe flexion: S1/2 "Curl down toes" sciatic small muscles of foot
• Toe extension: L5 S1 Sciatic nerve toe extensors "curl toes up"

Reflexes

• Knee : L3/L4
• Ankle : S1/S2
• Babinski - rub pen along lateral border and toes should curl
• If reflexes are increased look for clonus at the ankle and patella
• If reflexes are not found then try using reinforcement

Coordination

• Heel shin test: Same as finger nose in many ways but using feet
• Run right heel along left shin and lift off and place on left patella and run it down again. Alternate sides.
• Can even ask the patient to touch examiners finger with large toe
• Ask patient to place one heel on alternate patella with eyes closed

Heel-toe gait

• A useful test of motor dysfunction - formerly a test of acute alcohol intoxication a well-known depressant of cerebellar function
• Patient walks with heel to toe. Look for ataxia. A useful tests of neurological impairment

Interpretation

• Patterns of weakness to recognise(once a weakness is found use tone and reflexes to determine if UMN or LMN)
• Pyramidal e.g. stroke: Upper limb extensors weaker than flexors, lower limb flexors weaker than extensors
• Proximal weakness: Unable to raise arms above head, get out of the chair - suggests a myopathic weakness or Myasthenia or Guillan-Barre syndrome
• Fatigable weakness: Myasthenia gravis
• Distal symmetrical weakness: Peripheral neuropathy or Inclusion body myositis
• Hemiparesis Face/arm/leg: suggests contralateral intracranial pathology
• Hemiparesis Arm and Leg: Contralateral intracranial pathology or cervical cord pathology
• Weakness both legs - suggests cord or cauda equina damage
• Hemiparesis and contralateral cranial nerve signs suggest brainstem lesion e.g. right IIIrd nerve and C/L hemiparesis

Motor Roots

• C5 - radial side of forearm and reduced biceps reflex and power
• C6 - deficit in the thumb and first finger and decreased bicep and brachioradialis
• C7 - deficit in middle and ring finger and reduced triceps jerk
• C8 - Deficit in little finger and reflexes are normal
• T1 - T12 - pain in distribution but no weakness. Can cause chest wall pain. Mistaken as cardiac pain.
• L2 - sensory deficit lateral and anterior thigh weak psoas and quadriceps. Reflexes normal
• L3 - sensory deficit lower medial thigh weak psoas and quadriceps. Reduced knee jerk
• L4 - sensory deficit medial lower leg. Decreased knee jerk
• L5 - Lateral lower leg. Weak. No reflex abnormality
• S1 - lateral foot and with weak gastrocnemius. Reduced ankle jerk

Key movements of the Upper limb

Key movements of the lower Limb

Lower Limb Neurology

• Wash hands and introduce yourself to the patient and examiners
• Ensure you listen to what the examiner has asked
• Ensure the patient
  • Has given consent - introduce yourself and ask if you can examine
  • Is comfortable usually lying in bed with lower limbs exposed
  • Is decent - usually wearing underwear or shorts
• Inspection around patient
  • Look for walking sticks, frames
  • Skin: scars, neurofibromas, look at back spina bifida - pigmentation or hair patch
  • Shagreen patches
  • Urinary catheter
• Inspection from end of bed
  • Muscle bulk/wasting/tenderness
  • Look for Fasciculations (LMN lesion, MND, root compression, peripheral neuropathy, primary myopathy, thyrotoxicosis)
  • Look for any pill rolling or fine or coarse tremor
  Ask if you can assess Gait - or you may also do this at end of exam
  • Hemiplegia: the foot is plantar flexed and the leg is swung in a lateral arc
  • Spastic paraparesis: scissors gait
  • Parkinson's: starting hesitation, shuffling, freezing, festination, pro/retropulsion
  • Cerebellar: drunken wide-based or reeling on a narrow base gait; staggers towards side of cerebellar lesion
  • Posterior column lesion: clumsy slapping down of the feet on a broad base
  • Footdrop: high stepping gait
  • Proximal myopathy: waddling gait
  • Prefrontal lobe (apraxic): feet appear glued to floor when erect, but move more easily when the patient is supine
  • Hysterical: characterised by a bizarre, inconsistent gait
• Specific Actions
  • Test heel to toe walking – unable to with a midline cerebellar lesion
  • Test walking on toes (L4/5) & heels (S1)
  • Squatting to standing test (L3/4, proximal myopathy)
  • Romberg test (stand feet together eyes open, when steady close eyes & if becomes markedly unsteady loss of proprioception). Unsteadiness with eyes open (cerebellar)
• Tone
  • Test tone at knee & ankle: roll leg, lift thigh letting knee flex, and flex & extend knee & ankle
  • Test for Clonus: dorsiflex ankle with knee bent and also move patella sharply down on extended knee.
• Power: Assess MRC Grades
  • 0 – no movement
  • 1 – flicker of contraction
  • 2 – movement if gravity eliminated
  • 3 – can overcome gravity but not resistance
  • 4 – moderate movement against resistance
  • 5 – normal power.
• Quick screening power tests
  • Squat & stand again (L3/4)
  • Stand on heels (L4/5)
  • Stand on toes (S1/2)
• Hip
  • Flexion (L2/3)
  • Extension (L5, S1/2)
  • Abduction (L4/5, S1)
  • Adduction (L2/3/4)
• Knee
  • Flexion (L5, S1)
  • Extension (L3/4)
• Ankle
  • Plantar flexion (S1/2)
  • Dorsiflexion (L4/5)
  • Eversion (L5,S1)
  • Inversion (L5,S1)
• Reflexes: Allow tendon hammer to fall freely. Reinforce with teeth clench/hand interlocking if necessary.
  • Knee (L3/4)
  • Ankle (S1/2)
  • Plantar (L5, S1/2) – up lateral side or sole and curve inwards behind toes.
• Coordination
  • Heel-shin test - run heel up & down opposite shin
  • Toe-finger test – lift leg short distance to touch examiner’s finger with hallux.
  • Foot tapping – rapid foot tapping with sole against examiners hand.

Sensation

• Note hemisensory, dermatomal, peripheral nerve or stocking distribution of any abnormality.
• Always test on arm or face first.
  • Pain (& temperature): With pin (use both blunt & sharp ends) test dermatomes:
    • L1 - lateral groin
    • L2 - lateral ant thigh
    • L3 – medial ant thigh
    • L4 – medial ant calf
    • L5 – lateral ant calf
    • S1 – lateral foot, heel
    • S2 – popliteal fossa
    • S3 – central buttock, S4/5 –perianal)
  • Vibration & proprioception
    • Test vibration sense with 128Hz tuning fork over hallux, if absent test malleolus of ankle, knee