Acute Myelopathy

Authors:

Talha Nazir MD,

Awais Khan MD

Introduction

• The incidence of acute myelopathy vary based on etiologies e.g., Transverse myelitis (1400 new cases each year), Spinal epidural abscess (1.2 per 10,000 people) and Multiple Sclerosis (>100/100,000 people).

• The traumatic spinal cord injury often results from a gunshot wound (10.4%), accidental trauma to head, neck and back region (31.5%), falling (25.3%) and spinal sports injuries (4.3%).

• Non-traumatic spinal cord injuries can have a range of etiologies like degenerative changes, infections (Staph. Aureus and Mycobacterium tuberculosis), malignancy of spine (Primary: multiple myelomas, Metastasis: prostate in male and breast in females are common etiologies), inflammation or congenital abnormalities

Acute Myelopathy

Compressive Myelopathies

Abscess related myelopathy

• The common causative organisms are staphylococcus aureus and mycobacterium tuberculosis

• Risk factors include IV drug abuse, diabetes, alcohol

• Fever and local tenderness that may progress to neurological deficit.

• Commonly involve thoracic and lumbar regions

• MRI is diagnostic (well-defined enhancement of perilesional area and edema)

• Treat with antimicrobial therapy and surgery

Vascular malformation

• Vascular malformation can lead to compressive or non-compressive myelopathy

• Etiology

• Thrombosis of Aortic surgery, spinal angiography, embolism, and coagulative disorders

• Occlusion of arteries such as anterior spinal artery (Anterior spinal cord syndrome), posterior spinal artery (posterior spinal cord syndrome) and sub-commissural artery (brown Sequard syndrome) can lead to different presentations.
• AV fistula
• Venous infarct
• Spinal aneurysm
• Hemangioblastoma and cavernous malformation

• Imaging Findings
• MRI
• Serpent like images
• Absence of flow signals

• CSF Findings
• CSF is normal, but protein concentration may be higher in AV fistulas.
• Low cell content and absent oligoclonal bands

Non-compressive myelopathies

Transverse myelitis

• Bilateral spinal cord dysfunction with a well-defined area of sensory loss during the first four weeks of presentation without any compression or disease and evidence of spinal inflammation (CSF pleocytosis, raised IgG)

• Peak incidence is during the 2nd and 4th decade of life.

• Perivascular and medullary infiltration of monocytes, lymphocytes (acute) and macrophages (subacute).

• MRI Findings
• Central and focal high signal areas
• Involvement of three to four segments (thoracic spine is the most common)
• Diffuse enhancement on contrast medium (differentiate from other intramedullary tumors)

• Management
• IV corticosteroids (methylprednisolone, dexamethasone)
• Plasma exchange
• Immunosuppressive therapy for relapses

Infections related myelopathy

• Associated with blood-borne infections of lungs, skin and genitourinary system.

• Etiologies can be classified and based on the causative organism (Table 3)

• CSF Findings
• Pleocytosis
• Neutrophilia
• Increased protein
• Absent oligoclonal bands

• MRI Findings
• Central high signal areas
• Spinal edema
• Management
• Appropriate antibiotics
• Surgical intervention (epidural abscess, subdural empyema etc.)

Multiple sclerosis

• Autoimmune demyelination of nerves in brain and spinal cord. Associated with HLA-DR2. Symptoms include

• Relapsing and remitting symptoms. Common in women of 20 and 30 years old.

• Immune-mediated inflammation may lead to demyelination of axons in CNS (brain and spinal cord)

• Optic neuritis (associated with Marcus Gun pupil)

• Brainstem and cerebellar involvement (bilateral involvement is more common)

• Demyelination of pyramidal tract (spasticity)

• MRI Findings
• Gold standard
• Periventricular plaques
• Multiple lesion in white matter

• CSF Findings
• Raised IgG levels
• Oligoclonal bands (diagnostic)

• Management
• IV steroids for acute flares
• Prevent relapses by disease-modifying therapy (beta-interferon)
• Catheterization and anticholinergic drugs for neurogenic bladder
• Baclofen for spasticity
• TCAs (Tricyclic antidepressants) for pain

Neuromyelitis Optica

• Incidence is 0.4 per million in western population with a male to female ratio of 1:3

• Acute myelitis and optic neuritis along with two or more than two of the following

• Spinal cord lesion involving more than three segments

• IgG positive (aquaporin four antibodies)

• CSF Findings
• Raised protein
• Pleocytosis
• Absent oligoclonal bands

• MRI Findings
• Central longitudinal lesion (confluent) involving more than three segments
• Spinal expansion in T1 (low signals) and T2 (high signals)
• Periventricular lesion in more than 60% of the patients (high aquaporin four concentration)
• Optic nerve lesion

• Management
• Acute
• IV methylprednisolone (100mg for 3-5days)
• Plasmapheresis (5-7 cycles)
• Chronic
• Immunosuppression (Rituximab, Mycophenolate mofetil, azathioprine)
• Change the drug or optimize the dose if patient relapses.

Workup for acute myelopathy

• History and physical examination

• Neurological deficit and involvement of bladder and bowel

• To rule out a compressive myelopathy

• Step 3a: Define the infectious causes of myelopathy
• Pleocytosis
• Neutrophilia
• Increased protein
• Absent oligoclonal bands

• Step 3b: Define the inflammatory causes of myelopathy
• Raised IgG and oligoclonal bands (MS)
• IgG against aquaporin 4, raised proteins, pleocytosis and absent oligoclonal bands (Neuromyelitis Optica)

• Step 3c: Determine the location of the lesion
• Brain and spinal cord (MS)
• Spinal cord only (Transverse myelitis)
• Optic nerve and spinal cord (Neuromyelitis Optica)

Table 1: Etiologies of Compressive and Non-compressive Myelopathies

Table 2: Tumors causing Compressive Myelopathy

Table 3: Infections of Spinal cord

Further Reading

• Marignier R. Acute and subacute myelopathy. Rev Neurol (Paris). 2021 May;177(5):557-566. doi: 10.1016/j.neurol.2020.08.003. Epub 2020 Oct 21. PMID: 34024334.

• Hays, Angela & Chalela, Julio. (2010). Acute Myelopathy. 10.1007/978-1-4419-6842-5_19.

Bibliography

• Ana María Granados Sánchez, L. M. G. P., César Andrés Ortega Toscano, Alejandra López López. (2011). DIAGNOSTIC APPROACH TO MYELOPATHIES Rev. Colomb. Radiology, 22(3), 1-21.

• American spinal injury association. (2019 ). International Standards for Neurological Classification of SCI (ISNCSCI) Worksheet. from https://asia-spinalinjury.org/international-standards-neurological-classification-sci-isncsci-worksheet/

• Walker, J. (2009). Spinal cord injuries: acute care management and rehabilitation. Nursing Standard, 23(42), 47-56. doi: 10.7748/ns2009.06.23.42.47.c7055