Myelopathies

Question 1

What is a myelopathy? What is myelitis?

Answer 1

Definition of Myelopathy —> Myelopathy: A broad term referring to spinal cord disease or dysfunction.
• Spinal cord lesions which lead to motor, sensory, and sphincteric dysfunction.
• Timely recognition & treatment can prevent irreversible damage (paresis, paralysis).
• Prognosis depends on early & accurate diagnosis.

Myelitis instead is a subgroup of myelopathies caused by an inflammatory process like those in MS, NMOSD, ADEM.

Question 2

Classification of myelopathies?

Answer 2

Based on type of onset :
- Ictal (seconds, minutes): vascular occlusion (most frequent is an ischemic lesion in the spinal cord), trauma (causing the spinal cord transection), compressive lesion (herniation, tumour).
- Acute (hours, days): most frequent in patients with compressive myelopathies, but can also occur in
patients with MS.
- Subacute (development of symptoms over the course of 2-6 weeks): MS, NMOSD, ADEM, infectious, idiopathic, sarcoidosis.
- Chronic (>6 weeks): B12 or copper deficiency, syrinx (forming within central portion of the spinal cord), arterio-venous fistula.

Based on evolution of symptoms :
- Monophasic (cord affected just once): vascular occlusion, trauma, compressive lesions, ADEM, infectious conditions affecting the spinal cord, idiopathic.
- Multiphasic: MS, NMOSD, sarcoidosis.
- Stable: vascular occlusion, trauma. There are cases in which once the spinal cord is affected the manifestations of its involvement remain stable, so deficits are present and remain identical despite the progression of time.
- Progressive: MS, NMOSD, infectious, B12 or copper deficiency, syrinx, compressive, arterio-
venous fistula. In this case, once the spinal cord is affected, there’s a progressive worsening of symptoms over time.

Question 3

Etiology of myelopathies?

Answer 3

1. Traumatic/compressive : trauma, disc herniation, cyst, hematoma.
2. Demyelinating : MS, NMOSD, NBD, PACNS.
3. Infectious : bacterial, viral, fungal, parasitic.
4. Vascular : arteriovenous fistula, hypo perfusion injury.
5. Neoplastic : lymphoma, leukemia, glioma.
6. Paraneoplastic
7. Toxic/metablic : vitamin deficiency, copper deficiency.

Question 4

Topography of spinal cord lesions in myelopathies?

Answer 4

It is important to determine the level and location of a spinal cord lesions to further the diagnostic work up, predict clinical symptoms and differentiate between underlying causes.

The two major classifications :
• Sagittal (vertical) involvement → Cervical, thoracic, lumbar.
• Axial (cross-sectional) involvement → Gray matter vs. white matter tracts.

Classification based on lesion location :
- Extradural —> Outside the spinal cord but within the vertebral canal. Causes include herniated disc, tumors abscess, trauma, spondylosis, epidural hematoma

• Intradural —> Inside the dura but outside the spinal cord. Causes include meningioma, schwannoma, arachnoid cyst, vascular malformations
• Intramedullary —> inside the spinal cord (affecting gray/white matter). Causes include MS, NMOSD, MOGAD, sarcoidosis, vascular infarcts, syringomyelia.

Question 5

Clinical presentation of a spinal cord lesions?

Answer 5

1. Clinical Assessment of Spinal Cord Involvement
   • Step 1: Define Topography of Involvement, unilateral vs. Bilateral, symmetric vs asymmetric.
   • Which functional systems are affected? Pyramidal (motor), sensory (vibration, proprioception, pain, temperature), autonomic (sphincter control, blood pressure regulation)
   • Step 2: Look for Associated Systemic Symptoms
   • Fever → Infectious (viral, bacterial, parasitic)
   • Rash → Infectious, connective tissue diseases (SLE, vasculitis)
   • Altered mental state → ADEM, infections, metabolic
   •Meningismus (neck stiffness, headache) → Infectious meningitis, subarachnoid hemorrhage

Question 6

Spinal Cord Injury definition and epidemiology?

Answer 6

SCI = Damage to the spinal cord causing temporary or permanent neurological dysfunction.
Types of SCI:
• Traumatic SCI → Due to external impact (e.g., car accidents, falls, sports injuries, violence).
• Non-Traumatic SCI → Due to underlying disease (e.g., tumors, infections, autoimmune myelopathies, degenerative disc disease).

Epidemiology:
• Traumatic SCI: 15-39 cases per million/year.
• Non-Traumatic SCI: 364-1227 cases per million/year.
• More common in males (79.8%), bimodal peak: 15-29 years (young adults) & >50 years (degenerative causes).

Question 7

Pathophysiology of Spinal Cord Injury?

Answer 7

1. Acute Phase (0-48 hours)
   Primary Injury:
   • Direct mechanical damage to neurons and glial cells.
   • Hemorrhage and ischemia lead to further cell death.
   Secondary Injury Cascade:
   • Edema, inflammatory cell infiltration.
   • Cytokine release (IL-1, TNF-α) → cytotoxic damage.
   • Necrosis & apoptosis of neurons and oligodendrocytes → demyelination and axonal degeneration.
2. Subacute Phase (2-4 days)
   Worsening ischemia due to:
   • Vessel thrombosis and vasospasm.
   • Persistent inflammation → cell death.
   • Astrocytes proliferate → Form extracellular matrix scar.
3. Chronic Phase (2 weeks – 6 months)
   • Astroglial scar matures, preventing regeneration.
   • Axonal degeneration continues, leading to cavity formation.
   • Irreversible clinical deficits develop.

Question 8

Clinical Manifestations of Spinal Cord Injury?

Answer 8

1. Neurogenic Shock (Above T6)
   • Due to loss of sympathetic control.
   Signs :
   • Hypotension
   • Bradycardia
   • Warm, flushed skin (vasodilation)
2. Spinal Shock
   • Temporary loss of spinal cord function below the injury.
   Four Phases:
   1. Areflexia/Hyporeflexia (Edema → transmission failure).
   2. Return of Reflexes (Edema resolution, ischemia, tissue loss).
   3. Hyperreflexia (Loss of inhibitory descending signals).
   4. Spastic Paralysis (Irreversible motor impairment in severe cases).

Question 9

Levels of Spinal Cord Injury & corresponding deficits?

Answer 9

• C1-C4 (High Cervical) —> Quadriplegia, respiratory failure (C3-C5 → diaphragm paralysis).

-C5-C6 —> Quadriparesis, preserved breathing, weak arm function-

• C7-T1 —> Weakness in hands, full arm function.
• T2-T6 —> Paraplegia, neurogenic shock (above T6)
• T7-T12 —> Paraplegia, autonomic dysfunction (bladder, bowel, sexual function)
• L1-L2 (Conus Medullaris Syndrome) —> Bilateral lower limb weakness, early sphincter dysfunction
• L2-S5 (Cauda Equina Syndrome) —> Areflexic paralysis, saddle anesthesia, urinary retention (surgical emergency!)

Question 10

Diagnostic workup of Spinal Cord Injury?

Answer 10

Imaging :
1. X-ray → Fractures, dislocations.
2. CT Scan → More sensitive for bony fractures.
3. MRI Spine → Gold standard for soft tissue damage:
• Edema (acute phase)
• Hemorrhage
• Demyelination (MS, NMOSD)
• Compression (tumors, herniations).
Neurophysiological test like MEPs, SSEPs, EMG and nerve conduction studies .

Question 11

Management of Spinal Cord Injury?

Answer 11

1. Acute Management
   Airway & Breathing:
   • High cervical injury (C1-C5) → Intubation & mechanical ventilation.
   Circulatory Support:
   • Neurogenic shock → IV fluids + vasopressors (norepinephrine, dopamine).
   Corticosteroids:
   • Controversial → Limited role in acute SCI, only used in autoimmune myelopathies.
   Surgical decompression:
   • Herniated disc compressing spinal cord.
   • Spinal fractures with instability.
   • Tumors or infections causing compression.
2. Rehabilitation & Long-Term Management
   • Physical Therapy → Prevents muscle atrophy & joint contractures.
   • Bladder & Bowel Management.

Question 12

What is syringomyelia?

Answer 12

Syringomyelia → Chronic cystic cavitation (syrinx) within the spinal cord, most often at C8-T1.

Pathogenesis:
• The syrinx starts within the central canal and gradually expands, disrupting nearby neural structures.
• Primary syringomyelia: congenital (Chiari malformation, developmental anomalies).
• Secondary syringomyelia: acquired (post-trauma, meningitis, spinal cord tumors, arachnoiditis).

Epidemiology:
• Prevalence: 8.4 per 100,000 people.
• Age of onset: 35-50 years.
• Gradual progression over months to years.

Question 13

Pathophysiology and clinical features of syringomelia?

Answer 13

Syrinx location: Central grey matter (C8-T1), often extending anteriorly to involve anterior horn cells.

Progression:
1. Early Stage: Syrinx disrupts the anterior commissure → loss of pain & temperature sensation.
2. Expansion:
• Anterior horn involvement → flaccid paralysis of the upper limbs.
• Lateral column involvement → spastic paralysis of lower limbs (if corticospinal tracts affected).
• Posterior column involvement → loss of proprioception & vibration.

Clinical features include : sensory features like loss of pain and temperature, motor features like flaccid paralysis, autonomic features like urinary retention and fecal incontinence, skeletal features like scoliosis.

Question 14

Diagnosis and treatment of syringomelia?

Answer 14

Diagnosis :
1. MRI Spine (Gold Standard)
Findings:
• Fluid-filled cavity in the central spinal cord.
• May extend over multiple vertebral segments.
• Can be associated with Chiari malformation.
2. Additional Investigations
• CSF analysis: Normal (excludes infectious or inflammatory causes).
• Electromyography (EMG): Confirms anterior horn dysfunction.

Treatment & Management
Mild cases:
• Observation & yearly MRI monitoring.
• Physical therapy to maintain mobility & strength.
• Pain management: Gabapentin, pregabalin (neuropathic pain), NSAIDs/opioids if necessary.

Surgical Intervention (Indicated if progressive symptoms)
• Chiari decompression (if associated Chiari malformation).
• Syrinx drainage (shunt or direct syringotomy).
• Spinal cord untethering (if adhesions are causing CSF obstruction).

Question 15

Non compressive myelopathies?

Answer 15

• Non-compressive myelopathy refers to spinal cord dysfunction not caused by mechanical compression (e.g., herniated discs, tumors, trauma).
• Often immune-mediated (inflammatory/demyelinating), vascular, infectious, metabolic, or paraneoplastic.

Key distinction: whether MRI is abnormal or normal.
• Abnormal MRI → suggests inflammatory, vascular, or neoplastic causes.
• Normal MRI → suggests metabolic, toxic, or degenerative disorders.

Question 16

What are non compressive myelopathies?

Answer 16

• Non-compressive myelopathy refers to spinal cord dysfunction not caused by mechanical compression (e.g., herniated discs, tumors, trauma).
• Often immune-mediated (inflammatory/demyelinating), vascular, infectious, metabolic, or paraneoplastic.

Key distinction: whether MRI is abnormal or normal.
• Abnormal MRI → suggests inflammatory, vascular, or neoplastic causes.
• Normal MRI → suggests metabolic, toxic, or degenerative disorders.

Question 17

Clinical features of non-compressive myelopathies?

Answer 17

1. Acute Transverse Myelitis (ATM)
   • Inflammatory myelopathy with acute/subacute onset.
   • Sensory & motor deficits develop over hours to days and plateau in 3 weeks.
   Common Features:
   • Ascending numbness & tingling, typically starting in one leg → progresses to both.
   • Paraparesis or quadriparesis.
   • Hyperreflexia & spasticity (if corticospinal tract involved).
   • Bladder/bowel dysfunction (if lower cord involved).
   • Dissociated sensory loss (seen in syringomyelia, NMOSD).
   • Oppenheim hand sign → Useless hand due to posterior column dysfunction.
2. Motor Dysfunction
   • Early phase: Lower motor neuron (LMN) features in segmental lesion level.
   • Later phase: Upper motor neuron (UMN) signs below lesion level.
   • Hypertonia, hyperreflexia, Babinski sign (if corticospinal tract affected).
   • Spasticity & clonus (in progressive myelopathies).
   • Flaccid paralysis (if anterior horn cells involved, e.g., NMOSD).
3. Sensory Dysfunction
   • Sensory loss pattern depends on lesion location:
   • Posterior column → Proprioception/vibration loss → Ataxia.
   • Anterior commissure → Dissociated sensory loss (syringomyelia).
   • Lateral spinothalamic tract → Pain & temperature loss.
4. Bladder, Bowel, & Sexual Dysfunction
   Bladder dysfunction:
   • Failure to store (urgency, frequency, incontinence) → Autonomic/Corticospinal dysfunction.
   • Failure to empty (hesitancy, retention) → Detrusor-sphincter dyssynergia.
   • Bowel dysfunction: Constipation (common).
   • Sexual dysfunction.

Question 18

What is acute vascular myelopathy?

Answer 18

Definition & Overview
• Acute vascular myelopathy refers to spinal cord dysfunction due to vascular compromise.
• Most commonly due to ischemia (spinal cord infarction) but can also be hemorrhagic.

Pathophysiology:
• The spinal cord relies primarily on the aorta for blood supply, making it susceptible to ischemic damage during aortic surgery, dissection, or embolization.
• The anterior spinal artery (ASA) supplies the anterior two-thirds of the spinal cord.
• The posterior spinal arteries (PSA) supply the posterior third (posterior columns).
• Anterior cord syndrome is the most common vascular myelopathy

Question 19

Clinical features, etiologies and imaging features of ischemic myelopathy?

Answer 19

Clinical Features
• Acute, sudden onset of symptoms (minutes to hours).
• Initial flaccid paralysis (spinal shock phase) → Later evolves into spastic paralysis.
Dissociated sensory loss:
• Loss of pain & temperature sensation (Spinothalamic tract affected).
• Preserved proprioception & vibration (Posterior columns spared).
Autonomic dysfunction:
• Atonic bladder, bowel dysfunction, sexual dysfunction.
• Possible respiratory failure if lesion is above C4-C5.

Common Etiologies
1. Aortic Surgery (e.g., aneurysm repair, dissection surgery).
2. Spinal Angiography (iatrogenic embolism).
3. Vasculitis (e.g., SLE, PAN).
4. Embolic sources:
• Cardiac (e.g., atrial fibrillation, endocarditis).
• Cholesterol emboli (e.g., post-catheterization).
5. Aortic or Vertebral Dissection.
6. Hypotensive Episodes (“watershed infarcts” in spinal cord).
7. Prothrombotic states.

MRI Features
• Hyperintensity in the anterior spinal cord (T2-weighted MRI).
• “Pencil-like” lesion extending along multiple vertebral segments.
• “Snake eye” or “Owl eye” pattern in the central grey matter (pathognomonic).
• No significant enhancement unless secondary inflammation.

Question 20

Clinical features, etiologies and imaging features of ischemic myelopathy?

Answer 20

Clinical Features
• Acute, sudden onset of symptoms (minutes to hours).
• Initial flaccid paralysis (spinal shock phase) → Later evolves into spastic paralysis.
Dissociated sensory loss:
• Loss of pain & temperature sensation (Spinothalamic tract affected).
• Preserved proprioception & vibration (Posterior columns spared).
Autonomic dysfunction:
• Atonic bladder, bowel dysfunction, sexual dysfunction.
• Possible respiratory failure if lesion is above C4-C5.

Common Etiologies
1. Aortic Surgery (e.g., aneurysm repair, dissection surgery).
2. Spinal Angiography (iatrogenic embolism).
3. Vasculitis (e.g., SLE, PAN).
4. Embolic sources:
• Cardiac (e.g., atrial fibrillation, endocarditis).
• Cholesterol emboli (e.g., post-catheterization).
5. Aortic or Vertebral Dissection.
6. Hypotensive Episodes (“watershed infarcts” in spinal cord).
7. Prothrombotic states.

MRI Features
• Hyperintensity in the anterior spinal cord (T2-weighted MRI).
• “Pencil-like” lesion extending along multiple vertebral segments.
• “Snake eye” or “Owl eye” pattern in the central grey matter (pathognomonic).
• No significant enhancement unless secondary inflammation.

Question 21

Clinical features, etiologies and imaging features of hemorrhagic myelopathy?

Answer 21

Clinical Features
• Very rare but a neurosurgical emergency.
• Sudden-onset severe back pain or radicular pain.
• Rapidly evolving neurological deficits (seconds to minutes).
• Autonomic dysfunction (bladder/bowel loss).
• Compression of spinal cord if hemorrhage expands.

Common Etiologies
1. Vascular Malformations:
• Dural arteriovenous fistulas (dAVF).
• Spinal cord AVMs (arteriovenous malformations).
2. Coagulopathy or Hemorrhagic Diathesis:
• Anticoagulation therapy (e.g., Warfarin, DOACs).
• Thrombocytopenia, hemophilia.
3. Trauma or Iatrogenic causes.
4. Spinal Cord Tumors (Hemorrhagic metastases or hemangioblastomas).
5. Spontaneous Epidural Hematoma.

MRI & Angiography
• Acute hematoma seen on T1/T2 MRI.
• Cord compression in epidural hemorrhage.
• Spinal angiography is needed for arteriovenous malformations (AVMs).

Question 22

Treatment for ischemic and hemorrhagic myelopathy?

Answer 22

Spinal Cord Infarction
1. Supportive Care:
• High-dose IV fluids to maintain perfusion.
• Blood pressure control (avoid hypotension).
2. Aspirin or Antiplatelet Therapy (if embolic source identified).
3. Anticoagulation (in case of a hypercoagulable state or atrial fibrillation).
4. Rehabilitation & Prevention:
• Physical therapy to prevent contractures.
• Intermittent catheterization for neurogenic bladder.

Spinal Cord Hemorrhage
1. Emergency Neurosurgical Evaluation:
• Surgical decompression if epidural hematoma.
• Embolization for vascular malformations.
2. Reversal of Anticoagulation:
• Vitamin K, FFP, or PCC for warfarin-induced bleeding.
• Desmopressin (DDAVP) or platelet transfusion for thrombocytopenia.
3. Supportive Care:
• Pain management (opioids, muscle relaxants).
• Blood pressure control (SBP <140 mmHg to prevent rebleeding).

Question 23

What is vitamin B12 deficiency and subacute combined degeneration? Clinical features?

Answer 23

Vitamin B12 (cobalamin) is essential for myelin synthesis and DNA synthesis. Deficiency leads to progressive demyelination, particularly affecting the posterior columns and lateral corticospinal tracts of the spinal cord.
• Subacute → Symptoms develop over weeks to months.
• Combined → Affects both posterior columns & lateral corticospinal tracts.
• Degeneration → Begins as demyelination (reversible) but progresses to axonal degeneration (irreversible) if untreated.

Neurological Symptoms
Demyelination of the posterior columns:
• Loss of proprioception & vibration sense.
• Sensory ataxia (wide-based, unsteady gait).
• Positive Romberg sign (worsening of balance with eyes closed).
• Paraesthesia (“pins and needles”) in hands and feet.
Demyelination of the lateral corticospinal tract:
• Spastic paresis or paralysis (UMN signs).
• Hyperreflexia, clonus.
• Positive Babinski sign.
Demyelination of the spinocerebellar tracts:
• Ataxia, poor coordination.
Demyelination of optic nerve:
• Optic atrophy → Visual disturbances.
Demyelination of autonomic pathways:
• Bladder dysfunction.

Peripheral Neuropathy
• Symmetric distal sensorimotor polyneuropathy.
• “Glove and stocking” paraesthesia.
• Decreased reflexes in advanced cases

Question 24

Diagnosis and treatment of vitamin B12 deficiency SCD?

Answer 24

Diagnosis is based on :
- Serum Vitamin B12,↓ Low (<200 pg/mL) (BUT may be normal in early stages)
- Methylmalonic acid (MMA),↑ Elevated (more sensitive than B12 level)
- Homocysteine,↑ Elevated (also elevated in folate deficiency)
- Complete Blood Count (CBC),Macrocytic anemia (MCV >100 fL), hypersegmented neutrophils
- Intrinsic Factor Antibodies,Present in pernicious anemia
- Schilling test (historical),Used to determine cause of B12 malabsorption.

Treatment :
Vitamin B12 Replacement
If neurological symptoms are present:
• IM Cyanocobalamin or Hydroxocobalamin:
• 1000 mcg IM daily for 1 week → Then weekly for 4 weeks → Then monthly for life.
• Oral Cyanocobalamin (1000–2000 mcg daily) is an alternative for non-severe cases.
If no neurological symptoms:
• Oral B12 (1000 mcg/day) is sufficient.

Treat Underlying Cause
• Pernicious anemia → Lifelong B12 injections.
• Dietary deficiency → Increase intake of meat, fish, eggs, dairy.
• Gastric bypass, Crohn’s, SIBO → Long-term B12 monitoring.
• Stop offending drugs (Metformin, PPIs if possible).