1. Vivian & slides from ESA mentoring 2013
Neuro tract lesions
Vivian & slides from
ESA mentoring 2013

2. Upper motor neuron lesions
Pyramidal
(Corticospinal tract)
Extrapyramidal
Babinski sign
Spastic paralysis – increased muscular tone and hyperactive reflexes
Absent superficial abdominal reflexes
Little or no muscular atrophy
Absent cremasteric reflex
Exaggerated deep muscle reflexes
Loss of performance of fine skilled voluntary movements
Flapping clonus
Hypertonia and clasp knife response
In practice they occur together!

3. Lower motor neuron lesions
Flaccid paralysis
 tone, focal muscle atrophy
Focal muscle weakness
or absent reflexes
Fasciculations

4. N.B.
Lesions of the basal ganglia and cerebellum are also referred to as “extrapyramidal” but they are different to the UMN lesions – they don’t involve the descending motor tracts.

5. Sensory & combined lesions
Subacute combined degeneration of the cord
Tabes Dorsalis
Brown-Sequard syndrome
Syringomyelia
Spinal shock

6. Subacute combined degeneration of the cord
Cause
B12 deficiency (usually pernicious anaemia)
Pathology
Degeneration of the dorsal columns (myelin degeneration)
Signs & symptoms
• Legs, arms, trunk – progressive from tingling and numbness to weakness
• Visual impairment
• Change in mental state
• BILATERAL spastic paresis/paralysis
• Sensations diminished = pressure, vibration and touch
Clinical tests
• +ve Babinski sign = extensor plantar reflex
• +ve Rhomberg test
Treatment
Reversible with B12 replacement if not been going on for too long

7. Tabes dorsalis Cause Untreated syphilis Pathology
Degeneration of the dorsal columns (myelin degeneration)
Signs & symptoms
• Weakness, episodes of intense pain & disturbed sensation
• Ataxia (tabetic gait), loss of coordination
• Change in mental state e.g. dementia
• Visual impairment
• Sensations diminished = pressure, vibration and touch
Clinical tests
• +ve Rhomberg test
Treatment
IV Penicillin
Analgesics
Contact tracing!
Tabetic gait = due to loss of proprioception, patient’s feet slap to the ground as they walk

8. Syringomyelia What is it?
Enlarged cavity or cyst in the cervical/upper thoracic region of the cord
Cause
Congenital e.g. Arnold-Chiari malformation
Tumours
Trauma, haemorrhage
Meningitis
Signs & symptoms
Abnormal or loss of sensations
Chronic pain
Usually spare dorsal columns – intact pressure, vibration, touch, proprioception
May have ANS symptoms
Clinical tests
Cervical/Thoracic MRI
Treatment
Treat underlying causes
Surgery to drain cysts

9. Brown-Séquard syndrome = hemisection of the cord
Corticospinal tracts & dorsal columns decussate in the thalamus -> loss on same side
Spinothalamic tracts decussate as soon as they go into the cord (or 1-2 levels above) -> loss on contralateral side
Also loss of movements on the same side (corticospinal tracts – UMN signs below lesion, LMN signs at level of lesion)

10. Spinal shock Follows acute severe damage to the spinal cord.
<24 hours – 4 weeks
Depression or total loss of sensation and motor function below the level of the lesion.
Often associated with profound hypotension due to loss of sympathetic vasomotor tone.

11. How to approach a clinical case
Determine if there are any motor deficits
If yes what descending tracts are affected?
Is it pyramidal or extrapyramidal?
Is it an upper or lower motor neuron lesion?
Determine if there are any sensory deficits
If yes what ascending tracts are affected?
Determine if there are any cognitive problems
If yes then the damage probably has occurred in the brain?
What region effects the change in behaviour you have witnessed?
Where does the deficit start and end?
Torso/ limbs?
Dermatomes and myotomes are useful here
Is it sensory/ motor/ both & is the lesion central or peripheral?
What side of the body are they on?
Indicates side of lesion
Are the sensory and motor deficits on the same side?
Is the lesion above or below the level of decussation of the tracts involved

12. Case 1
Pt presents with neck pain, paraesthesia in the medial side of the arm and hand, weakness affecting the whole hand and extension and abduction of the wrist joint. Bicep reflexes are normal but tricep reflex is absent.
Lower motor neuron (Weakness. Absent tricep reflex)
Neither pyramidal or extrapyramidal signs
Level of the common root of the spinal nerve as both sensory and motor signs

13. Case 2
Pt presented with normal right arm and leg movement and minimal/ absent movement of left side with increased muscle tone and clasp knife rigidity. Pt had a flexor plantar reflex on the right and a babinski reflex on the left. Pt also had impaired facial movements on the left but with forehead sparing.
Upper motor neuron (increased muscle tone and clasp knife rigidity, babinski sign, forehead sparing)
Pyramidal and extrapyramidal signs
Most likely occurred in the brain because forehead sparing so needs to occur above pons

14. Case 3
Pt presents with weakness in his left arm and hand. Has no sensory loss. Reduced grip on the left side with increased muscle tone. Biceps and brachioradialis jerks are exaggerated. Right side grip is also reduced and reflexes are brisk.
UMN (weakness with increased tone and reflexes)
Extrapyramidal
Lower brain stem or upper spinal cord small lesion as no sensory loss or corticospinal involvement

15. Case 4
Pt presents with mild slurring of speech, blindness in right eye and tingling in the left side of her face, difficulty swallowing, weakness, numbness and hyperreflexia in the right leg with a babinski sign in the right foot
Both upper and lower
Both pyramidal and extrapyramidal
Multiple anatomically unrelated lesions (MS)

16. Thank you!