Localising the lesion

1. Localising the lesion Ed Hutchison and Paul Swift

2. Aims • Approach • UMN vs. LMN • Spinal tracts • Cerebellum • Cerebrum • Visual lesions • Cases

3. Approach to localising the lesion Be systematic! …A patient presents with arm weakness…

4. Muscle – e.g. diabetic myopathy NMJ – e.g. myasthenia gravis Peripheral nerve – e.g. GBS Spinal cord – e.g. cord compression Cerebrum – e.g. Stroke

5. Timeline

6. UMN vs. LMN • ???

7. UMN vs. LMN

8. Pyramidal vs. Extrapyramidal

9. Clonus • http://www.youtube.com/watch?feature=player_detailpage&v=8GC8F2UMYbQ#t=42

10. Facial nerve palsies • Bulbar vs. pseudobulbar • Pseudobulbar = UMN of CN IX-XII • Spastic tongue • Sparing of forehead • Bulbar = LMN of CN IX-XII • Tongue wasting/fasciculation • Affects all facial muscles

12. The tracts ? Dorsal column Corticospinal ? ? Spinothalamic

13. Lateral Spinothalamic Pain and temperature Decussates at the level of the spinal cord

14. Anterior Spinothalamic Crude touch and pressure Decussates at the level of the spinal cord

15. Dorsal columns Discrimination, proprioception, vibration. Crosses at the medulla. Subacute combined degeneration of the cord, Tabesdorsalis, Spinal trauma.

16. Corticospinal Tracts Descending motor tracts. Cross at the medulla.

17. Brown-Sequard

18. Brainstem CN IX-XII • Symptoms/signs: • Dysarthria • Dysphagia/drooling • Tongue weakness • Absent palatial movement

19. Cerebellum Cerebellospinal tracts Ipsilateral – DO NOT CROSS

20. Blood Supply

21. Cerebellar Signs D A N I S H – dysdiadochokinesia – ataxia (truncal and limb) – nystagmus – intention tremor – slurred speech – hypotonia

22. Causes • Alcohol • Thiamine deficiency • CVA • Friedreich’s ataxia Etc etc…

23. The Homunculus

24. Cerebral Artery Territories

26. Circle of Willis Anterior cerebral artery Middle cerebral artery ? Posterior cerebral artery Basilar artery A = ? Vertebral artery Anterior spinal artery B = ?

27. Speech Centres

28. Tono man • http://www.youtube.com/watch?v=6CJWo5TDHLE

29. Broca’s dysphasia • http://www.youtube.com/watch?v=1aplTvEQ6ew

30. Stroke Syndromes

31. Visual Defects Ipsilateralblindess Bilateral hemianopia Left homonymous hemianopia Left superior quadrantanopia Left homonymous hemianopia with macular sparing

32. Cases

33. Case 1 • 57 year old man complaining of weakness and altered sensation in upper limbs and lower limbs • Loss of sensation from shoulders and down, urinary incontinence • On Examination: • CN intact • Upper limbs weakness, hypotonia, reduced reflexes • Lower limbs spasticity, hyper-reflexia and Babinski +ve, reduced sensation from shoulders down

34. Case 2 • 85 year old man with long standing (20yr) history of balance problems worse in the dark. • Gait is high stepping • On Examination: • CN intact • Motor intact • Loss of proprioception with +ve Romberg’s test

35. Case 3 • 23, female presents to her GP with a 2 week history of bilateral leg weakness having started with pins and needles and numbness in her hands and feet. She has had a few days of urinary incontinence which has resolved. 2 years ago she had an episode of blurred vision and pain in the right eye which lasted a month and fully resolved

36. Case 4 • 56 male • 6 month history of progressive weakness of his right hand. Also had problems with swallowing and has choked whilst eating on several occasions • o/e he has wasting of his upper and lower limbs and some fasciculation's were noted his right plantar was up going and his reflexes were generally brisk

37. Things we’ve not had time to cover • Peripheral neuropathies • Motor neurone • Parkinson’s • Huntington’s • GBS • Myasthenia gravis

38. Peripheral Neuropathies • A – alcohol • B – B12 deficiency • C – CKD • D – drugs/diabetes • E – every vasculitis