Demystifying the neurology examination

1. Demystifying the neurology examination Dr BSF Stacey, Consultant Physician

2. Aims • Introduce the principles underpinning a structured neurological examination • Revise some neuroanatomy • Show some pathologies • Not creating instant experts • Not the only neurology talk you’ll ever need to attend • Not a substitute for practice

3. Format • Cranial nerves • Names and function • Some anatomy • Motor system • Reflexes • Sensory system • Some practicalities of examination • Cranial nerves and more anatomy • Limbs • Images • Normality and pathology

4. Cranial nerves Arms Torso Legs Higher mental function Observation Tone Power Co-ordination Reflexes Sensation Light touch Proprioception Vibration sense Pin prick Temperature I - XII

5. Cranial nerves Arms Torso Legs Higher mental function Observation Ex/Pyr Tone C/Sp Power C/Sp Co-ordination Cblr Reflexes Sensation Light touch Proprioception D/Col Vibration sense Pin prick S/Thal Temperature Gait

7. 1 2 3 4 6 Smell Vision Eye movements Cranial nerves

8. 5 7 8 9 10 12 11 Face –motor and sensory Face –motor (+ taste) Hearing and balance Palatal movement and gag reflex Tongue movement Head/shoulder movements Cranial nerves

9. Cranial nerves – 1 Olfactory • Sense of smell • Rarely formally tested • Ask directly • Bedside foodstuffs

10. Cranial nerves – 2 Optic • Visual acuity • Snellen chart, newspaper • Visual fields • Direct light reflex • (Consensual light reflex)

11. Pupil Retina Optic nerve III Optic chiasm Lateral geniculate bodies Ciliary ganglion Edinger-Westfahl nucleus Pretectal nucleus

12. L R Visual fields Retina Optic nerve Optic chiasm P Bitemporal hemianopia Optic radiation RIGHT homonymous hemianopia

13. Cranial nerves – 3, 4 and 6 Occulomotor, Trochlear and Abducens • Eye movements, pupil dilatation • SO4, LR6 • Double vision? Nystagmus? INO? • Ptosis

14. Cranial nerves – 5 Trigeminal • Motor • Masseter, temporalis • Sensory • Va, Vb, Vc • Corneal reflex (unpleasant)

15. Cranial nerves – 7 Facial • Motor • Frontalis (UMN v LMN) • Other facial muscles • Stapedius • Sensory • Taste from anterior 2/3 of tongue via chordi tympani

16. Cranial nerves – 8 Vestibulocochlear • Hearing • Crude bedside testing • Balance • Rinne • Normal is positive • Weber • Towards a conductive defect

17. Cranial nerves – 9 and 10 Glossopharyngeal and vagus • Palatal movement with “aaaah” • Gag reflex – bilateral • IX: taste from posterior 1/3 of tongue

18. Cranial nerves – 12 Hypoglossal • Tongue movement (NB: fasciculation) • Deviates towards the lesion

19. Cranial nerves – 11 Accessory • Shoulder and head movements • Sternocleidomastoid and trapezius muscles

20. Cranial nerves – ‘epilogue’ Fundoscopy! • Optic disc - only part of the brain that you can see • Retina, vessels • Cataracts

21. The Motor System • Corticospinal system = pyramidal - Cortex  anterior horn cells - skilled, strong, organized movement • Extra-pyramidal = basal ganglia - facilitates fast fluid movements • Cerebellum - coordination • Lower motor neurones

22. 1. Corticospinal tracts • Main nerve fibres meet in internal capsule • Cross in medulla • Lesions  UMN signs = contralateral hemiparesis, spasticity NB: upper limb drift (UL: flexors; LL extensors predominate) • Causes: • Most common = CVA • SOL • MS

23. Leg Cerebral cortex Arm Head and neck Internal capsule

24. 2. Extra-pyramidal system • Reduction in speed with muscle rigidity • Involuntary movements • Most common disorder = Parkinson’s

25. Cranial nerve nuclei Cerebral cortex Caudate nucleus Corpus striatum Globus pallidus Putamen Thalamus Substantia nigra Subthalamic nuclei Cerebellum Reticular formation Spinal cord

26. 3. Cerebellum • Coordination (rather than speed) • Lateral lobes coordinate ipsilateral limb • Vermis – axial posture and balance Signs: intention tremor, ataxia, nystagmus, dysarthria (bilateral)

27. 4. Lower motor neurones • Motor pathway from anterior horn cell (or cranial nerve nucleus) via peripheral nerve to end plate • Weakness, hypotonia, wasting, loss of reflexes • Causes: • Bell’s, MND, polio • Spinal root compression • Peripheral nerve trauma, entrapment, mononeuritis multiplex

28. UMN v LMN Cortex UMN LMN Muscle Spasticity Flaccidity

29. Reflexes – the spinal reflex arc • Activation of stretch receptors = first order sensory neurones • Synapse directly with motor efferent fibres at local spinal level • Activate LMNs  contraction REINFORCEMENT

30. Myotomes

32. Reflexes – spinal levels • Supinator C 5-6 • Biceps C 5-6 • Triceps C 7-8 • Knee L 3-4 • Ankle S 1-2 Plantar reflex

33. Reflexes – spinal levels • Supinator C 5-6 • Biceps C 5-6 • Triceps C 7-8 • Knee L 3-4 • Ankle S 1-2 Plantar reflex

34. Reflexes – spinal levels • Supinator C 5-6 • Biceps C 5-6 • Triceps C 7-8 • Knee L 3-4 • Ankle S 1-2 Plantar reflex

35. Reflexes – spinal levels • Supinator C 5-6 • Biceps C 5-6 • Triceps C 7-8 • Knee L 3-4 • Ankle S 1-2 Plantar reflex

36. Reflexes – spinal levels • Supinator C 5-6 • Biceps C 5-6 • Triceps C 7-8 • Knee L 3-4 • Ankle S 1-2 Plantar reflex

37. Plantar reflex – Babinski’s sign • Normal = downgoing (flexor) • Extensor in UMN lesions • Most receptive – posterior 1/3 of the lateral aspect of the sole • Dorsiflexion and fanning of other toes

38. Abdominal reflex • Contraction of oblique muscles in response to sensory stimulus • Ipsilateral loss in UMN lesions

39. Sensory pathways • Posterior columns • Spinothalamic tracts

40. Posterior columns • Travel ipsilaterally to brainstem, then cross to form medial lemniscus and pass to the thalamus • Carry: • light touch (and 2-point discrimination) • vibration sense • proprioception (joint position sense)

41. Spinothalamic tracts • Axons synapse in the dorsal horn and cross within two levels • Then pass to the thalamus and reticular formation • Carry: • pain • temperature

42. Sensory symptoms • Paraesthesia • Numbness • Pain • Quality and distribution suggest site of lesion

43. Spinal root and cord lesions • Root pain • Worse with stretch • Posterior column lesions • Lhermitte’s phenomenon • Spinothalamic lesions • Dissociated sensory loss • Cord compression • External (tumour, abcess) or internal (syrinx)

44. The Practicalities

45. Clinical examination • Introduction • Shake hands (myotonia) • General observation • Tremor, chorea • Obvious wasting • Asymmetry • ‘Clues’ • Diabetic accessories • ‘White stick’

46. Cranial nerves • Face the patient • Observe for: • ptosis (NB: myasthenia), asymmetry, scars • Go through in logical order • (1) 2 ‘3 4 6’ 5(+r) 7 8 ‘9 10 12’ 11 • Equipment required: • Snellen chart, pen-torch, red hatpin, cotton wool, needle, orange stick, tuning fork, opthalmoscope

47. Clinical abnormalities • Horner’s syndrome • Unilateral pupillary constriction, partial ptosis, enopthalmos • Causes: • Brain stem – pontine glioma, LMS • Cervical cord – syringomyelia, tumour • T1 root lesions – bronchial apical tumour, cervical rib • Sympathetic chain in the neck – neoplastic infiltration, post-surgery, carotid artery occlusion • Others - congenital

48. Occular and pupillary abnormalities • Argyll Robertson pupil • neurosyphilis • Holmes-Adie pupil (myotonic pupil) • Internuclear opthalmoplegia • MS (lesion in MLF) • Diplopia • Strabismus (squint) • Paralytic, non-paralytic

49. Pontine nucleus of 5 6th nucleus Pons 7th nucleus Va VG SUPERIOR ORBITAL FISSURE Medulla Vb FORAMEN ROTUNDUM Spinal cord FORAMEN OVALE Vc Spinal nucleus of 5

50. Facial nerve palsies • Part of facial nucleus supplying frontalis receives supranuclear fibres from each hemisphere • UMN • Upper part of face spared • LMN • Whole face affected • Ramsay Hunt syndrome • Hyperacusis