Differentials
Compressive myelopathy
SIGNS / SYMPTOMS
Known history of cancer or recent trauma are risk factors.[65][66] Epidural abscess may be associated with known infection (e.g., TB) or fever. Compressive haematoma may occur in patients having anticoagulation. However, clinical features of the myelopathy are indistinguishable from TM.
INVESTIGATIONS
Spinal cord MRI with gadolinium.
Infectious myelitis (e.g., TB)
SIGNS / SYMPTOMS
May have systemic infectious syndrome.
INVESTIGATIONS
Specific tests for individual infections are positive.
Anterior spinal artery occlusion
SIGNS / SYMPTOMS
Anterior cord syndrome (paraparesis, sensory level, and sparing of posterior column dysfunction). Sudden or acute onset of symptoms.
History of aortic surgery, intra-operative hypotension, vasculitis, spinal angiography, systemic emboli, prothrombotic state.[67]
INVESTIGATIONS
Spinal cord MRI: thin linear lesion restricted to anterior two-thirds of the spinal cord cross-sectional area.
Posterior spinal artery occlusion
SIGNS / SYMPTOMS
Posterior column syndrome (impaired vibratory and proprioceptive functions). Sudden or acute onset of symptoms.
History of aortic surgery, intra-operative hypotension, vasculitis, spinal angiography, systemic emboli, prothrombotic state.[67]
INVESTIGATIONS
Spinal cord MRI shows focal lesion restricted to posterior one-third of the cord cross-sectional area.
Arteriovenous fistula
SIGNS / SYMPTOMS
Progressive myelopathy with step-wise deterioration; sometimes with positional features such as increased symptoms with walking or with Valsalva manoeuvre; combined upper and lower motor neuron syndrome.[68]
INVESTIGATIONS
Spinal cord MRI shows a long or patchy cord lesion, with or without cord swelling; heterogeneous gadolinium enhancement; presence of tortuous vessels on dorsal cord surface.
Spinal angiography confirms diagnosis.
Haematomyelia
SIGNS / SYMPTOMS
Known coagulopathy, anticoagulation, or vascular lesion such as cavernoma.
INVESTIGATIONS
MRI spinal cord: signal change consistent with blood products, appearance changes over time (acute compared with subacute or chronic).
Neoplastic myelopathy
SIGNS / SYMPTOMS
Known history of cancer is risk for intramedullary metastases.
Tumour infarction or haemorrhage may present acutely and mimic TM.
Primary tumours usually present as a subacute to chronic myelopathy without distinguishing clinical features.[65]
INVESTIGATIONS
MRI spinal cord shows irregular, heterogeneous, and enhancing cord lesion.
Persistent gadolinium enhancement lasting for several months.
Spinal cord biopsy confirms diagnosis.
Radiation myelopathy
SIGNS / SYMPTOMS
History of radiotherapy where field included spinal cord.
Usually presents as a delayed progressive myelopathy with cord atrophy but occasionally is subacute.[69]
INVESTIGATIONS
Spinal cord MRI shows cord atrophy and increased T2 signal in adjacent vertebrae in chronic cases.
Subacute lesions may mimic inflammatory TM but vertebrae are usually abnormal.
Electromyogram reveals myokymia in weak muscles.
Paraneoplastic myelopathy
SIGNS / SYMPTOMS
Sometimes known history of cancer.
May present as a 'tractopathy' with clinical features restricted to, for example, corticospinal tracts.[23][70]
INVESTIGATIONS
MRI spinal cord may reveal bilateral, symmetric, and enhancing signal abnormality restricted to anatomical long tracts.
Positive paraneoplastic antibody panel for antibodies such as amphiphysin, collapsin response mediated protein-5, antineuronal nuclear antibody-2, neuronal acetylcholine receptor antibodies, P/Q or N-type calcium channel antibodies, voltage-gated potassium channel antibodies, Purkinje's cell antibodies, or glutamic acid decarboxylase antibodies.
Discovery of occult tumour with body imaging (CT, MRI, or PET).
Fibro-cartilaginous embolism
SIGNS / SYMPTOMS
Sudden deficit associated with physical exertion, spine pain, and anterior spinal artery syndrome.[71]
INVESTIGATIONS
Spinal cord MRI shows a cord signal abnormality with adjacent loss of intervertebral disc height and end-plate micro-fractures.
Cerebral lesion
SIGNS / SYMPTOMS
Headache for some causes such as hydrocephalus, stroke (arterial or venous).
INVESTIGATIONS
MRI brain confirms diagnosis.
Acute inflammatory demyelinating polyradiculoneuropathy (Guillain-Barre syndrome)
SIGNS / SYMPTOMS
Subacute flaccid weakness with hyporeflexia or areflexia, paraesthesia but little or no demonstrable sensory impairment.[72]
INVESTIGATIONS
MRI spinal cord negative; may reveal enlarged and enhancing spinal roots.
Cerebrospinal fluid shows elevated protein but normal WBC.
Electromyogram demonstrates peripheral abnormalities.
Plexopathy
SIGNS / SYMPTOMS
Subacute lower extremity pain, weakness, and sensory symptoms, usually asymmetric; patients with diabetes or metastatic cancer.
INVESTIGATIONS
MRI spinal cord negative.
MRI lumbosacral plexus may show nerve enhancement or nodularity consistent with metastases.
Electromyogram demonstrates peripheral abnormalities.
Motor neuron disorder
SIGNS / SYMPTOMS
Chronic, progressive painless weakness without sensory symptoms or bladder involvement; mixed upper and lower motor neuron signs.
INVESTIGATIONS
Negative spinal cord MRI.
Characteristic clinical examination and electromyogram findings.
Myasthenia gravis
SIGNS / SYMPTOMS
Fatigable weakness without pain, sensory symptoms, or autonomic involvement.
INVESTIGATIONS
Positive acetylcholine receptor antibodies, positive edrophonium test, abnormal electromyogram.
Copper deficiency
SIGNS / SYMPTOMS
Patient at risk for nutritional deficiency based on diet, medical disease, or surgery (especially bariatric/gastric surgery).[73]
INVESTIGATIONS
Low serum copper level.
Vitamin B12/folate deficiency
SIGNS / SYMPTOMS
Patient at risk for nutritional deficiency (e.g., bariatric/gastric surgery).
History of nitrous oxide inhalation abuse.
Painless weakness, ataxia, and sensory symptoms.
INVESTIGATIONS
Low serum B12 level, macrocytic anaemia, elevated serum homocysteine and methylmalonic acid levels, history of recent nitrous oxide exposure, MRI spinal cord may show lesion in dorsal columns and/or corticospinal tracts.
Use of this content is subject to our disclaimer