Approach to unilateral UMNL and Brown Sequard Syndrome

Question 1

What are the causes of unilateral UMNL?

Answer 1

Cortical, subcortical and brainstem
1. Stroke - cortical, subcortical, brainstem
2. Multiple sclerosis affecting unilateral
3. Neoplastic - tumours
4. Infective - abscess

Spinal cord
5. Brown sequard syndrome
6. Multiple sclerosis

Question 2

Possible distribution of UMN weakness

Answer 2

Exceptions:
1. Patchy UMN weakness or multiple UMN deficits that do not fit into a single lesion
- Multiple sclerosis.
- Multiple cortical strokes.
2. Brown sequard syndrome:
- Ipsilateral spastic hemiparesis with DCML loss + contralateral loss of pinprick sensation

Question 3

Unilateral UMNL Dance

Answer 3

1. Examine UL or LL as per stem
   - Identifying unilateral UMNL pattern with spasticity, contracture, hyperreflexia, weakness
   - Look out for distribution of sensation loss
   > Ipsilateral unilateral DCML loss + contralateral spinothalamic loss -> think Brown Sequard syndrome
   > Ipsilateral spinothalamic loss + examine CN -> think cortical/subcortical/brainstem
2. Cerebellar signs
3. Cranial neuropathy
   - Cortical: contralateral CN + limb
   - Brainstem: ipsilateral uncrossed CN nuclei + contralateral crossed descending corticospinal fibres
   - Distinguish between UMN vs. LMN CN VII palsy
4. Higher cortical signs
   - Frontal: gaze preference, acalculia, personality change
   > Broca area: non-fluent expressive aphasia
   - Parietal: hemineglect, abnormal line bisection
   - Temporal: memory loss
   > Wernicke area: fluent receptive dysphasia
   - Occipital: visual field defect with macular sparing
5. Complications
   - Fine motor tasks (button shirt, use handphone).
   - Mobility - use of walking aid or wheelchair.
   - Swallowing - nasogastric tube.
   - Urinary function - urinary catheter or diapers.
6. Exploring mechanisms of infarct
   A. Haemorrhagic: signs of anticoagulation, injuries
   B. lschaemic
   - Cardioembolic: irregularly irregular pulse
   - Artery-to-artery embolism: carotid bruit
   - Large vessel disease: atherosclerosis (xanthalesma, archus senilis)
   - Small vessel disease: diabetes (BGM marks, request blood pressure)
   - Existing cardiovascular disease: sternotomy scar, lower limb amputations

Question 4

Neuro-localisation of unilateral UMNL

Answer 4

Assume initial examination of left hemiparesis

Question 5

Brown-sequard syndrome is a hemiscection (one-sided injury) of the spinal cord

Resulting in: (MVP same side, pain other side):
- Ipsilateral UMN spastic paralysis
- Ipsilateral DCML loss
- Contralateral spinothalamic loss
+/- LMN at level (anterior horn) and Horner’s syndrome (cervical)

Causes:
1. Trauma and wound
2. Spinal cord tumours
3. Multiple sclerosis
4. Vascular - infarct, AVM
5. Transverse myelitis
6. Infectious - TB, syphilis
7. Radiation myeloapthy
8. Syringomyelia - rarely presents this way

Question 6

Examination findings and signs of Brown-Sequard Syndrome

Answer 6

1. Ipsilateral UMN below level
   - Hemiparesis/hemiplegia, spasticity, hyperreflexia, muscle weakness, positive Babinski
2. Ipsilateral DCML loss below level
   - Loss of vibration, proprioception, 2-point discrimination
3. Contralateral spinothalamic loss below level
   - Loss of pain and temperature
   - Usually 1-2 segments below level of lesion (fibres decussate 1-2 segments before ascending)
4. Entire hemi-cord damage - LMNL at level
   - Ipsilateral LMN (anterior horn damage)
   - Ipsilateral pan-sensory loss (dorsal horn damage)
5. Additional features
   - Neuropathic pain
   - Bladder and bowel dysfunction
   - Respiratory failure (high cervical)
   - Ipsilateral Horner (above T1)

Question 7

Investigations of unilateral UMNL

Answer 7

1. CT and MRI brain and spine
2. Cervical cord evoked potential (in BSS)
3. CVRF screening - HbA1c, lipid panel
4. Lumbar puncture - oligoclonal IgG bands (in MS), identifying inflammatory or infections
5. NCS and EMG - demyelination vs axonal
6. Evoked potentials (SEP and MEP)

Question 8

Management of unilateral UMN

Answer 8

General
1. Multidisciplinary team: PT, OT, psychologist, Neurology

Symptomatic
2. Spasticity: baclofen, diazepam
3. Neuropathic pain: gabapentin, TCA, SSRI
4. Bladder/bowel dysfunction
5. DVT prophylaxis

Definitive
6. Ischaemic stroke: aspirin, statin, control CVRF
7. Acute Brown-Sequard:
- Methylprednisolone
- Haemodynamic support MAP >85-90
- Orthospine surgery
8. Multiple sclerosis: methylprednisolone, PLEX, interferon beta, natalizumab

Question 9

Comparison of other spinal cord syndromes

Answer 9