Diseases of the Spinal Cord

Disease description Many conditions constitute neurologic emergencies because of Severity on presentation (quadriplegia, sensory deficits, spinal shock) Potential reversibility Hallmark: presence of horizontally defined level below which motor, sensory and autonomic function is impaired

Approach to a Patient Determine level of lesion Identify special anatomic patterns, if any Determine time frame of the disease Differentiate compressive from non-compessive lesions

Determining level of the lesion Sensory level Using pinprick or cold stimulus Level indicates damage to the spinothalamic tract 1-2 segments above a unilateral lesion or at the level of the bilateral lesion

Determining level of the lesion Motor level Damage to the descending corticospinal tract Paraplegia or quadriplegia Upper motor neuron syndrome Autonomic abnormalities Sweating Bladder or bowel dysfunction

Determining level of lesion Manifestations Cervical Horner’s syndrome at any level Upper cervical: quadriplegia, diaphragm weakness Thoracic Localized by the sensory level on the trunk or midline back pain, if present Beevor’s sign (T9-T10 lesion leading to paralysis of lower abdominals, thus upward movement of umbilicus on abdominal contraction) Lumbar Lesions at L5-S1 abolish ankle jerk Sacral/conus medullaris Bilateral saddle anesthesia with urinary retention, fecal incontinence with lax anal tone, impotence

Determining level of the lesion Upper level of the lesion may be determined with segmental signs Hyperalgesia or hyperpathia Fasciculations or muscle atrophy Hypo- or areflexia

Special patterns

Special patterns Brown-Sequard syndrome Ipsilateral weakness (corticospinal), loss of joint and position sense (posterior column) Contralateral loss of pain or temperature sense 1-2 levels below the lesion (spinothalamic) Unilateral segmental signs

Special patterns Central cord syndrome Damge to gray matter and crossing spinothalamic tracts near central canal Arm > leg weakness Loss of pain and temperature sense with intact light touch, joint position and vibration sense (dissociated sensory loss)

Special patterns Anterior spinal artery syndrome Extensive bilateral deficits below the level of the lesion, with intact vibration and position sense Foramen magnum syndrome Damage to decussating pyramidal tract fibers of the legs “Around the clock” pattern of weakness with suboccipital pain

Special patterns Extramedullary Intramedullary Radicular pain Early sacral sensory loss, spastic leg weakness Intramedullary Sacral sparing

Time-frame of the disease Acute or severe transverse lesions may initially present as spinal shock (flaccidity, areflexia) in the first few days or weeks, rather than upper motor neuron signs May be mistaken for acute severe polyneuropathy or stratified to have more severe damage than actual

Compressive vs noncompressive myelopathy Compressive (mass) Tumor Epidural abscess or hematoma Herniated disc Vertebral pathology Non-compressive (intrinsic cord lesions) Vascular Inflammatory Infectious

Compressive myelopathies Tumors Extradural Intradural Intramedullary Epidural abscess Epidural hematoma Compressive myelopathies

Neoplastic spinal cord compression: Epidural neoplasms Mostly metastatic (breast, lung, prostate, kidney, lymphoma, myeloma) Thoracic cord most common except for prostate and ovarian cancers (lumbosacral) Pain is an early symptom, awakens patient at night and is worse with movement MRI is useful

Neoplastic spinal cord compression: Epidural Therapy Glucocorticoids Local radiotherapy Treatment of underlying tumor Fixed motor deficits of >12 hours do not usually improve and > 48 hours, prognosis is poor

Neoplastic spinal cord compression: Intradural Mostly slow-growing and benign Meningiomas, neurofibromas, also chordoma, lipoma, dermoid, sarcoma Present with radicular sensory symptoms followed by asymmetric progressive cord syndrome Therapy is surgical resection

Neoplastic spinal cord compression: Intramedullary Present as central cord or hemicord syndromes of the cervical region Ependymoma, hemangioblastoma or low-grade astrocytoma in adults Secondary metastatic lesions are also common

Spinal epidural abscess Triad: midline dorsal pain, fever, progressive limb weakness Risk factors: impaired immune status, intravenous drug abuse, infections of skin or otehr tissues Causes: Hematogenous spread Direct extension

Spinal epidural abscess Causative organsims Staph. Aureus Tuberculosis Gram-neg bacilli, Strep, anaerobes, fungi Lab tests MRI High cervical MRI (to rule out concomittant meningitis) Blood culture

Spinal epidural abscess Treatment Decompressive laminectomy with debridement with Empirical, then culture-guided, antibiotics for >4weeks

Spinal epidural hematoma Acute focal or radicular pain with variable cord findings Risk factors: anticoagulation, trauma, tumor or blood dyscrasia Labs MRI, CT Therapy is surgical decompression and correction of underlying problem

Noncompressive myelopathies Spinal cord infarction Inflammatory and immune myelitis Systemic inflammatory diseases SLE Demyelinating myelopathy Multiple sclerosis Post-infectious myelitis Acute infectious myelitis Noncompressive myelopathies

Spinal cord infarction “Watershed” infarcts T3-T4 and boundary zones between anterior and posterior spinal artery territories Rapidly progressive weakness and spasticity with little sensory change Usually associated with hypotension

Spinal cord infarction Anterior spinal artery infarct Anterior cord syndrome Paraplegia or quadriplegia, dissociated sensory loss, loss of sphincter control Onset may be sudden or progressive over hours Sharp midline back pain Initial spinal shock

Systemic inflammatory disorders Mostly due to SLE, specially with antiphopholipid antibodies CSF may be normal or show mild lymphocytic pleocytosis May respond to high dose steroids and cyclophosphamide

Demyelinating myelopathy Multiple sclerosis may present as myelitis Mild swelling and edema of the cord Multifocal areas of abnormal T2 signal on MRI Mild pleocytosis, oligoclonal band Hihg dose steroids, plasma exchange Neuromyelitis optica No oligoclonal bands May respond to anti-CD20 (rituximab)

Post-infectious or post-vaccinal myelitis Organisms implicated: EBV, CMV, mycoplasma, influenza, measles, varicella, rubeola, mumps Autoimmune disorder triggered by infection and not due to direct infection of spinal cord Treatment glucocorticoids,plasma exchange

Acute infectious myelitis Poliomyelitis, herpes zoster Bacterial or mycobacterial myelitis (abscess) Schistosomiasis

Chronic myelopathies Spondylitic myelopathy Vascular malformations of the cord and dura Syringomyelia Subacute combined degeneration Tabes dorsalis Familial spastic paraplegia Chronic myelopathies

Spondylitic myelopathy Most common cause of gait problems in the elderly Early neck and shoulder stiffness, later radicular pain Cord compression in <1/3 of patients Spastic paraparesis, paresthesia Reduced vibratory sense, (+) Romberg sgin Dermatomal sensory loss & decreased tendon reflex in the arms, intrinsic hand muscle atrophy Hyperreflexia in the legs

Vascular malformation of the cord & dura Slowly progressive or intermittent myelopathy with incomplete sensory, motor or bladder disturbance Spinal bruits Labs : high resolution contrast MRI, CT myelogram, selective spinal angiography Therapy: endovascular embolization

Syringomyelia Developmental cavitary expansion of the cervical cord, often associated with Chiari type I malformation Classic presentation is central cord syndrome (dissociated sensory loss, areflexi weakness of the arms) Symptoms progress as the syrinx expand

Subacute combined degeneration Vitamin B12 deficiency Subacute paresthesia in hands & feet, loss of vibration and position sense, progressive spastic & ataxic weakness Diffuse, symmetric myelopathy Predominant involvement of posterior and lateral tracts Associated peripheral neuropathy

Subacute combined degeneration Labs: macrocytic RBCs, low B12 concentration Therapy: replacement with intramuscular 1000ug vitamin B12 at regular intervals or subsequent oral treatement

Tabes dorsalis Complication of syphilis Fleeting and lancinating pains in the legs, wtih ataxia due to loss of position sense Loss of leg reflexes Impaired vibratory and position sense Romberg’s sign Argyll Robertson pupils Differential: diabetic polyradiculopathy

Familial spastic paraplegia Genetic defects of >20 different loci presenting as slowly progressive myelopathy Progressive spasticity and leg weakness Absent or mild sensory symptoms Sphincter disturbances + nystagmus, ataxia, optic atrophy Onset maybe from infancy to middle adulthood Therapy: symptomatic for spasticity

Summary Spinal cord conditions may present catastrophically but many have treatable causes Determine the level of the lesion and identify special patterns in the presentation to derive a diagnosis Address the conditions promptly

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