1. Localising the lesion – where in the nervous system?
CRAIG HICKSON & Helga Magnusson

2. Aims and objectives Definitions of the CNS & PNS
To learn the signs associated with LMN and UMN
Brief recap on the functions associated with different lobes
Cortical representation of body parts
Circle of Willis and blood supply to each hemisphere
Motor tracts – lateral corticospinal
Sensory – lateral spinothalamic & dorsal column
Clinic scenarios/Case vignettes

3. The central nervous system
‘The CNS consists of the and the
Some definitions include the and the retina ?

4. The peripheral nervous system
‘The PNS consists of the nerves and the ganglia outside of the brain and the spinal cord’
Includes autonomic NS and in most definitions the cranial nerves

5. Upper motor neuron signs
Spastic paralysis
Hypereflexia
Hypertonia
No muscle wasting – some wasting from lack of use eventually
Pyramidal weakness – flexion of upper limbs, extension of lower limbs
Positive Babinski – up-going plantar ?

6. Lower motor neuron signs
Flaccid paralysis
Hyporeflexia
Hypotonia
Muscle wasting
Fasiculations
Weakness of muscle groups – mytomes
-ve Babinski?

7. Lobar function
Fontal – personality, executive function, cognition, & primary motor cortex.
Left Frontal – Broca’s area
Parietal – primary sensory cortex
Occipital – vision
Temporal – hearing
Left Temporal – Wernicke’s area
Cerebellum – balance, co-ordination
Basal ganglia – initiation, inhibition of movement

8. Homonculus
Hands and face massively ‘over represented’ More sensitive

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

10. Blood supply to the brain

11. The tracts
Dorsal column ?
Corticospinal ? ?
Spinothalamic

12. Spinothalamic Contra-lateral Cross at entry level ?
pain and temp over 1 level
touch over several ?
Pain, Temperature, touch

13. Dorsal Column Contra-lateral Cross at Medulla ?
Vibration, propriaception
Discriminative touch

14. Corticospinal
Motor tracts
Contra-lateral
Cross at Medulla

15. How to think UMN or LMN signs?
LMN: peripheral nerve/neuromuscular junction/muscular.
UMN: cerebral (?lobe), cerebellar, spinal cord (?tract)
Can the symptoms be explained by one lesion?
Differential diagnosis:
Immediate: vascular.
Intermediate: inflammation/infection/malignancy.
Long term: degenerative/malignancy.

16. Cases
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
C-spine C4

17. What could have caused this picture?

18. Cases
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 propriaception with +ve romberg
Tabes dorsalis

19. What could have caused this picture?

20. Cases
35 year old lady who cant feel hot water when she puts her hand in the bath anymore
ON Examination
Sensation – pain and temp reduced in upper limbs
Light touch and propriaception retained
Syringomyelia

21. What could have caused this picture?

22. Cases
42 year old lady complaining of unsteadiness of balance and slurred speech, she has noticed weakness and loss of sensation in her left leg
Leg symptoms have been present for two months
Unsteadiness and slurred speech came on over last 10 days
On examination:
CN intact
Weakness left lower limb 4/5
Hyper-reflexia – left leg only
Coordination impaired on left
Mental state NAD
Cerebellar + spinal – 2 lesions, MS

23. What could have caused this picture?

24. Thankyou for listening and contributing

25. Stroke syndromes
TACI
PACI
POCI
LACI