Spinal cord disorders can cause permanent severe neurologic disability. For some patients, such disability can be avoided or minimized if evaluation and treatment are rapid. Spinal cord disorders usually result from conditions extrinsic to the cord—eg, compression due to spinal stenosis, herniated disk, tumor, abscess, or hematoma. Less commonly, disorders are intrinsic to the cord. Intrinsic insults include infarction, hemorrhage, transverse myelitis, arteriovenous malformation, HIV infection, poliovirus infection, syphilis (which can cause tabes dorsalis—trauma, vitamin B12 deficiency (which causes subacute combined degeneration—decompression sickness lightning injury (which can cause keraunoparalysis radiation therapy (which can cause myelopathy), syrinx, or spinal cord tumor Spinal nerve roots outside of the spinal cord may also be damaged
Anatomy
The spinal cord extends caudally from the medulla at the foramen magnum and terminates at the upper lumbar vertebrae, where it forms the conus medullaris. In the lumbosacral region, nerve roots from lower cord segments descend within the spinal column in a nearly vertical sheaf, forming the cauda equina.
The white matter at the cord's periphery contains ascending and descending tracts of myelinated sensory and motor nerve fibers. The central H-shaped gray matter is composed of cell bodies and nonmyelinated fibers The anterior (ventral) horns of the “H” contain lower motor neurons, which receive impulses from the motor cortex via the descending corticospinal tracts and, at the local level, from internuncial neurons and afferent fibers from muscle spindles. The axons of the lower motor neurons are the efferent fibers of the spinal nerves. The posterior (dorsal) horns contain sensory fibers that originate in cell bodies in the dorsal root ganglia. The gray matter also contains many internuncial neurons that carry motor, sensory, or reflex impulses from dorsal to ventral nerve roots, from one side of the cord to the other, or from one level of the cord to another. The spinothalamic tract transmits pain and temperature sensation contralaterally in the spinal cord; most other tracts transmit information ipsilaterally. The cord is divided into functional segments (levels) corresponding approximately to the attachments of the 31 pairs of spinal nerve roots.
Pathophysiology, Symptoms, and Signs
Neurologic dysfunction due to spinal cord disorders occurs at the involved spinal cord segment and at all segments below it. The exception is the central cord syndrome which may spare segments below.
Effects of Spinal Cord Dysfunction by Segmental Level
Location of Lesion* Possible Effects
At or above C5 Respiratory paralysis
Quadriplegia
Between C5 and C6 Paralysis of legs, wrists, and hands
Weakness of shoulder abduction and elbow flexion
Between C6 and C7 Paralysis of legs, wrists, and hands, but shoulder movement and elbow flexion usually possible
Between C7 and C8 Loss of biceps jerk reflex
Paralysis of legs and hands
At C8 to T1 Horner's syndrome (constricted pupil, ptosis, facial anhidrosis)
Paralysis of legs
Between T1 and conus medullaris Paralysis of legs
*Abbreviations refer to vertebrae; the cord is shorter than the spine, so that moving down the spine, cord segments and vertebral levels are increasingly out of alignment. At all levels of cord injury, deep tendon reflexes become brisk below the level of the lesion, bowel and bladder control is lost, and sensation is lost below the level of injury.
Spinal cord disorders produce various patterns of deficits depending on which nerve tracts within the cord or which spinal roots outside the cord are damaged. Disorders affecting spinal nerves, but not directly affecting the cord, cause sensory or motor abnormalities or both only in the areas supplied by the affected spinal nerves.
Spinal Cord Syndromes
Syndrome Cause Symptoms and Signs
Anterior cord syndrome Lesions disproportionately affecting the anterior spinal cord, commonly due to infarction (eg, caused by occlusion of the anterior spinal artery) All tracts malfunction except the posterior columns, thus sparing position and vibratory sensation
Brown-Séquard syndrome (rare) Unilateral spinal cord lesions, typically due to penetrating trauma Ipsilateral paresis
Ipsilateral loss of touch, position, and vibratory sensation
Contralateral loss of pain and temperature sensation*
Central cord syndrome Lesions affecting the center of the spinal cord, mainly central gray matter (including spinothalamic tracts, which cross), commonly due to trauma, syrinx, or tumors in the central spinal cord Paresis tending to be more severe in the upper than in the lower extremities and sacral regions
Tendency to lose pain and temperature sensation in a capelike distribution over the upper neck, shoulders, and upper trunk, with light touch, position, and vibratory sensation relatively preserved (dissociated sensory loss)
Conus medullaris syndrome Lesions around L1 Distal leg paresis
Perianal and perineal loss of sensation (saddle anesthesia)
Erectile dysfunction
Urinary retention, frequency, or incontinence
Fecal incontinence
Hypotonic anal sphincter
Abnormal bulbocavernosus and anal wink reflexes
Transverse myelopathy Lesions affecting all or most tracts of the spinal cord at ≥1 segmental levels Deficits in all functions mediated by the spinal cord (because all tracts are affected to some degree)
*Occasionally, only part of one side of the spinal cord malfunctions (partial Brown-Séquard syndrome).
Spinal cord dysfunction causes paresis, loss of sensation, reflex changes, and autonomic dysfunction (eg, bowel, bladder, and erectile dysfunction; loss of sweating). Dysfunction may be partial (incomplete). Autonomic and reflex abnormalities are usually the most objective signs of cord dysfunction; sensory abnormalities are the least objective.
Corticospinal tract lesions cause upper motor neuron dysfunction. Acute, severe lesions (eg, infarction, traumatic lesions) cause spinal shock with flaccid paresis (decreased muscle tone, hyporeflexia, and no extensor plantar responses). After days or weeks, upper motor neuron dysfunction evolves into spastic paresis (increased muscle tone, hyperreflexia, and clonus). Extensor plantar responses and autonomic dysfunction are present. Flaccid paresis that lasts more than a few weeks suggests lower motor neuron dysfunction (eg, due to Guillain-Barré syndrome).
Specific cord syndromes include transverse sensorimotor myelopathy, Brown-Séquard syndrome, central cord syndrome, anterior cord syndrome, and conus medullaris syndrome
Cauda equina syndrome, which involves damage to nerve roots at the caudal end of the cord, is not a spinal cord syndrome. However, it mimics conus medullaris syndrome, causing distal leg paresis and sensory loss in and around the perineum and anus (saddle anesthesia), as well as bladder, bowel, and pudendal dysfunction (eg, urinary retention, urinary frequency, urinary or fecal incontinence, erectile dysfunction, loss of rectal tone, abnormal bulbocavernosus and anal wink reflexes).
Diagnosis
Neurologic deficits at segmental levels suggest a spinal cord disorder. Similar deficits, especially if unilateral, may result from nerve root or peripheral nerve disorders, which can usually be differentiated clinically. Level and pattern of spinal cord dysfunction help determine presence and location of a spinal cord lesion but not always type of lesion.
MRI is the most accurate imaging test for spinal cord disorders; MRI shows spinal cord parenchyma, soft-tissue lesions (eg, abscesses, hematomas, tumors, abnormalities involving intervertebral disks), and bone lesions (eg, erosion, severe hypertrophic changes, collapse, fracture, subluxation, tumors). Myelography with a radiopaque dye followed by CT is used less often. It is not as accurate as MRI and is more invasive but may be more readily available. Plain x-rays may help detect bone lesions.
Acute Transverse Myelitis
Acute transverse myelitis is acute inflammation of gray and white matter in one or more adjacent spinal cord segments, usually thoracic. Causes include multiple sclerosis, infections, autoimmune or postinfectious inflammation, vasculitis, and certain drugs. Symptoms include bilateral motor, sensory, and sphincter deficits below the level of the lesion. Diagnosis is usually by MRI, CSF analysis, and blood tests. IV corticosteroids and plasma exchange may be helpful early. Otherwise, treatment is supportive measures and correction of any causes.
Acute transverse myelitis is most commonly due to multiple sclerosis but can occur with vasculitis, mycoplasmal infections, Lyme disease, syphilis, TB, or viral meningoencephalitis or in patients taking amphetamines, IV heroin, or antiparasitic or antifungal drugs. Transverse myelitis occurs with optic neuritis in a variant of multiple sclerosis called neuromyelitis optica (Devic disease—. The mechanism of transverse myelitis is often unknown, but some cases follow viral infection or vaccination, suggesting an autoimmune reaction. Inflammation tends to involve the spinal cord diffusely at one or more levels, affecting all spinal cord functions.
Symptoms and Signs
Pain in the neck, back, or head may occur. A bandlike tightness around the chest or abdomen, weakness, tingling, numbness of the feet and legs, and difficulty voiding develop over hours to a few days. Deficits may progress over several more days to a complete transverse sensorimotor myelopathy, causing paraplegia, loss of sensation below the lesion, urinary retention, and fecal incontinence. Occasionally, position and vibration sensation are spared, at least initially. The syndrome occasionally recurs in patients with multiple sclerosis, SLE, or antiphospholipid syndrome.
Diagnosis
Diagnosis is suggested by transverse sensorimotor myelopathy with segmental deficits. Guillain-Barré syndrome
can be distinguished because it does not localize to a specific spinal segment. Diagnosis requires MRI and CSF analysis. MRI typically shows cord swelling and helps exclude other treatable causes of spinal cord dysfunction (eg, spinal cord compression). CSF usually contains monocytes, protein content is slightly increased, and IgG index is elevated (normal, ≤ 0.85). A new and specific antibody marker for neuromyelitis optica (NMO-IgG), which distinguishes neuromyelitis optica from multiple sclerosis, has been recently described
Tests for treatable causes should include chest x-ray; PPD; serologic tests for mycoplasma, Lyme disease, and HIV; vitamin B12 and folate levels; ESR; antinuclear antibodies; and CSF and blood Venereal Disease Research Laboratory (VDRL) tests. History may suggest a drug as a cause. Brain MRI is done; multiple sclerosis develops in 50% of patients who have multiple periventricular T2 bright lesions and in 5% who do not have them.
Prognosis and Treatment
Generally, the more rapid the progression is, the worse the prognosis. Pain suggests more intense inflammation. About 1/3 of patients recover, 1/3 retain some weakness and urinary urgency, and 1/3 are bedridden and incontinent. Multiple sclerosis eventually develops in about 10 to 20% of the patients in whom the cause is initially unknown.
Treatment is directed at the cause or associated disorder but is otherwise supportive. In idiopathic cases, high-dose corticosteroids are often given and sometimes followed by plasma exchange because the cause may be autoimmune. Efficacy of such a regimen is uncertain.
Arteriovenous malformations
Arteriovenous malformations in or around the spinal cord can cause cord compression, ischemia, parenchymal hemorrhage, subarachnoid hemorrhage, or a combination. Symptoms may include gradually progressive, ascending, or waxing and waning segmental neurologic deficits; radicular pain; and sudden back pain with sudden segmental neurologic deficits. Diagnosis is by MRI. Treatment is with surgery or stereotactic radiosurgery and may include angiographic embolization.
Arteriovenous malformations (AVMs) are the most common spinal vascular malformations. Most are thoracolumbar, posterior, and outside the cord (extramedullary). The rest are cervical or upper thoracic and often inside the cord (intramedullary). AVMs may be small and localized or may affect up to half the cord. They may compress or even replace normal spinal cord parenchyma, or they may rupture, causing focal or generalized hemorrhage.
A cutaneous angioma sometimes overlies a spinal AVM. AVMs commonly compress nerve roots, causing pain that radiates down the distribution of a nerve root (radicular pain), or compress the spinal cord, causing segmental neurologic deficits that gradually progress or that wax and wane. Combined lower and upper motor neuron deficits are common. AVMs may rupture into the spinal cord parenchyma, causing sudden, severe back pain and sudden segmental neurologic deficits. Rarely, high cervical AVMs rupture into the subarachnoid space, causing sudden and severe headache, nuchal rigidity, and impaired consciousness
Spinal cord AVMs may be detected incidentally during imaging . AVMs are suspected clinically in patients with unexplained segmental neurologic deficits or subarachnoid hemorrhage, particularly those who have sudden, severe back pain or cutaneous midline angiomas. Diagnosis is by MRI, magnetic resonance angiography, selective arteriography, or, occasionally, myelography plus CT.
Surgery is indicated if spinal cord function is threatened, but expertise in specialized microtechniques is required. Stereotactic radiosurgery is helpful if the AVM is small and located in a surgically inaccessible location. Angiographic embolization occludes feeder arteries and often precedes surgical removal or stereotactic radiosurgery.
Cervical Spondylosis and Spondylotic Cervical Myelopathy
Cervical spondylosis is osteoarthritis of the cervical spine causing stenosis of the canal and sometimes cervical myelopathy due to encroachment of bony osteoarthritic growths (osteophytes) on the lower cervical spinal cord, sometimes with involvement of lower cervical nerve roots (radiculomyelopathy).
Cervical spondylosis due to osteoarthritis is common. Occasionally, particularly when the spinal canal is congenitally narrow (< style="font-weight: bold; color: rgb(153, 0, 0);">Hereditary spastic paraparesis
Hereditary spastic paraparesis is a group of rare hereditary disorders characterized by progressive, spinal, nonsegmental, spastic leg paresis, sometimes with mental retardation, seizures, and other extraspinal deficits.
The genetic basis of hereditary spastic paraparesis varies and, for many forms, is unknown. In all forms, the descending corticospinal tracts and, to a lesser extent, the dorsal columns and spinocerebellar tracts degenerate, sometimes with loss of anterior horn cells. Onset can be at any age, from the first year of life to old age, depending on the specific genetic form.
Symptoms and signs include spastic leg paresis, with progressive gait difficulty, hyperreflexia, clonus, and extensor plantar responses. Sensation and sphincter function are usually spared. The arms may also be affected. Deficits are not localized to a spinal cord segment. In some forms, patients also have extraspinal neurologic deficits (eg, spinocerebellar and ocular symptoms, extrapyramidal symptoms, optic atrophy, retinal degeneration, mental retardation, dementia, polyneuropathy).
Hereditary spastic paraparesis is suggested by a family history and any signs of spastic paraparesis. Diagnosis is by exclusion of other causes and sometimes by genetic testing.
Treatment for all forms is symptomatic. Baclofen Some Trade Names
LIORESAL
10 mg po bid, increased as needed up to 40 mg po bid, is given for spasticity. Alternatives include diazepam Some Trade Names
VALIUM
, clonazepam Some Trade Names
KLONOPIN
, dantrolene Some Trade Names
DANTRIUM
, botulinum toxin ( botulinum toxin type A Some Trade Names
BOTOX COSMETIC
BOTOX
or botulinum toxin type B Some Trade Names
MYOBLOC
), and tizanidine Some Trade Names
ZANAFLEX
Spinal Cord Compression
Various lesions can compress the spinal cord, causing segmental sensory, motor, reflex, and sphincter deficits. Diagnosis is by MRI. Treatment is directed at relieving compression.
Compression is caused far more commonly by lesions outside the spinal cord (extramedullary) than by lesions within it (intramedullary). Compression may be acute, subacute, or chronic.
Acute compression develops within minutes to hours. It is often due to trauma (eg, vertebral crush fracture with displacement of fracture fragments, disk herniation, metastatic tumor, severe bony or ligamentous injury causing hematoma, vertebral subluxation or dislocation). It is occasionally due to abscess and rarely due to spontaneous epidural hematoma. Acute compression may follow subacute and chronic compression, especially if the cause is abscess or tumor.
Subacute compression develops over days to weeks. It is usually caused by a metastatic extramedullary tumor, a subdural or an epidural abscess or hematoma, or a cervical or, rarely, thoracic herniated disk.
Chronic compression develops over months to years. It is commonly caused by bony protrusions into the cervical, thoracic, or lumbar spinal canal (eg, due to osteophytes or spondylosis, especially when the spinal canal is narrow, as occurs in spinal stenosis—. Compression can be aggravated by a herniated disk and hypertrophy of the ligamentum flavum. Less common causes include arteriovenous malformations and slow-growing extramedullary tumors.
Atlantoaxial subluxation and other craniocervical junction abnormalities may cause acute, subacute, or chronic spinal cord compression.
Lesions that compress the spinal cord may also compress nerve roots or, rarely, occlude the spinal cord's blood supply, causing infarction.
Symptoms and Signs
Acute or advanced spinal cord compression causes segmental deficits, paraparesis or quadriparesis, hyperreflexia, extensor plantar responses, loss of sphincter tone (with bowel and bladder dysfunction), and sensory deficits. Subacute or chronic compression may begin with local back pain, often radiating down the distribution of a nerve root (radicular pain), and sometimes hyperreflexia and loss of sensation. Sensory loss may begin in the sacral segments. Complete loss of function may follow suddenly and unpredictably, possibly resulting from secondary spinal cord infarction. Spinal percussion tenderness is prominent if the cause is metastatic carcinoma, abscess, or hematoma.
Intramedullary lesions tend to cause poorly localized burning pain rather than radicular pain and to spare sensation in sacral dermatomes. These lesions usually result in spastic paresis.
Diagnosis and Treatment
Spinal cord compression is suggested by spinal or radicular pain with reflex, motor, or sensory deficits, particularly at a segmental level. MRI is done immediately if available. If MRI is unavailable, CT myelography is done; a small amount of iohexol (a nonionic, low osmolar radiopaque dye) is introduced via a lumbar puncture and allowed to run cranially to check for complete CSF block. If a block is detected, a radiopaque dye is introduced via a cervical puncture to determine the rostral extension of the block. If traumatic bone abnormalities (eg, fracture, dislocation, subluxation) that require immediate spinal immobilization are suspected, plain spinal x-rays can be done. However, CT detects bone abnormalities better.
Treatment is directed at relieving pressure on the cord. Incomplete or very recent complete loss of function may be reversible, but complete loss of function rarely is; thus, for acute compression, diagnosis and treatment must occur immediately.
If compression is due to a tumor, IV dexamethasone Some Trade Names
DECADRON
DEXASONE
HEXADROL
100 mg is given immediately, followed by 25 mg q 6 h and immediate surgery or radiation therapy. Surgery is indicated in the following cases:
• Neurologic deficits worsen despite nonsurgical treatment.
• A biopsy is needed.
• The spine is unstable.
• Tumors recur after radiation therapy.
• An abscess or a compressive subdural or epidural hematoma is suspected.
Spinal cord infarction
Spinal cord infarction usually results from ischemia originating in an extravertebral artery. Symptoms include sudden and severe back pain, bilateral flaccid limb weakness, and loss of sensation, particularly pain and temperature. Diagnosis is by MRI. Treatment is generally supportive.
The primary vascular supply for the posterior 1/3 of the spinal cord is the posterior spinal arteries and for the anterior 2/3, the anterior spinal arteries. Each of the anterior spinal arteries has only a few feeder arteries in the upper cervical region and one large feeder, the artery of Adamkiewicz, in the lower thoracic region. The feeder arteries originate in the aorta.
Because collateral circulation for the anterior spinal artery is sparse in places, certain cord segments (eg, those around the 2nd to 4th thoracic segments) are especially vulnerable to ischemia. Injury to an extravertebral feeder artery or the aorta (eg, due to atherosclerosis, dissection, or clamping during surgery) causes infarction more commonly than do intrinsic disorders of spinal arteries. Thrombosis is an uncommon cause, and polyarteritis nodosa is a rare cause.
Sudden pain in the back with tightness radiating circumferentially is followed by segmental bilateral flaccid weakness and sensory loss. Pain and temperature sensation are disproportionately impaired. The anterior spinal artery is typically affected, resulting in the anterior cord syndrome Position and vibration sensation, conducted by the posterior columns, and often light touch are relatively spared. If the infarct is small and affects primarily tissue farthest away from an occluded artery (toward the center of the cord), central cord syndrome is also possible. Neurologic deficits may partially resolve after the first few days.
Infarction is suspected when severe back pain and characteristic deficits develop suddenly. Diagnosis is by MRI. Acute transverse myelitis, spinal cord compression, and demyelinating disorders may cause similar findings but are usually more gradual and are excluded by MRI and by CSF analysis.
Occasionally, the cause of infarction (eg, aortic dissection, polyarteritis nodosa) can be treated, but often the only possible treatment is supportive.
Spinal Epidural Abscess
A spinal epidural abscess is an accumulation of pus in the epidural space that can mechanically compress the spinal cord.
Spinal epidural abscesses usually occur in the thoracic or lumbar regions. An underlying infection is often present; it may be remote (eg, endocarditis, furuncle, dental abscess) or contiguous (eg, vertebral osteomyelitis, decubitus ulcer, retroperitoneal abscess). In about 1/3 of cases, the cause cannot be determined. The most common causative organism is Staphylococcus aureus, followed by Escherichia coli and mixed anaerobes. Occasionally, the cause is a tuberculous abscess of the thoracic spine (Pott's disease). Rarely, a similar abscess occurs in the subdural space.
Symptoms begin with local or radicular back pain and percussion tenderness, which become severe. Fever is common. Spinal cord compression may develop; compression of lumbar spinal roots may cause cauda equina syndrome, with neurologic deficits resembling those of conus medullaris syndrome (eg, leg paresis, saddle anesthesia, bladder and bowel dysfunction). Deficits progress over hours to days.
The diagnosis is suggested by characteristic neurologic deficits and by back pain worsened by recumbency, particularly in patients who have a fever or have had a recent infection. Diagnosis is by MRI; myelography followed by CT can be used if MRI is not available. Samples from blood and infectious areas are cultured. Lumbar puncture is contraindicated because it may trigger cord herniation if the abscess causes complete obstruction of CSF. Plain x-rays are not routinely indicated but may show osteomyelitis in about 1/3 of patients.
Antibiotics with or without parenteral needle aspiration may be sufficient; however, abscesses producing neurologic compromise (eg, paresis, bowel or bladder dysfunction) are surgically drained immediately. Pus is gram-stained and cultured. Pending culture results, antibiotics to cover staphylococcus and anaerobes are given as for brain abscess If the abscess developed after a neurosurgical procedure, an aminoglycoside is added to cover gram-negative bacteria.
Spinal Subdural or Epidural Hematoma
A spinal subdural or epidural hematoma is an accumulation of blood in the subdural or epidural space that can mechanically compress the spinal cord.
Spinal subdural or epidural hematoma (usually thoracic or lumbar) is rare but may result from back trauma, anticoagulant or thrombolytic therapy, or, in patients with bleeding diatheses, lumbar puncture.
Symptoms begin with local or radicular back pain and percussion tenderness; they are often severe. Spinal cord compression may develop; compression of lumbar spinal roots may cause cauda equina syndrome and lower extremity paresis. Deficits progress over minutes to hours.
Hematoma is suspected in patients with acute, nontraumatic spinal cord compression or sudden, unexplained lower extremity paresis, particularly if a possible cause (eg, trauma, bleeding diathesis) is present. Diagnosis is by MRI or, if MRI is not immediately available, by CT myelography.
Treatment is immediate surgical drainage. Patients taking coumarin anticoagulants are given phytonadione Some Trade Names
MEPHYTON
(vitamin K1) 2.5 to 10 mg sc and fresh frozen plasma as needed to normalize INR. Patients with thrombocytopenia are given platelets
Syrinx
A syrinx is a fluid-filled cavity within the spinal cord (syringomyelia) or brain stem (syringobulbia). Predisposing factors include craniocervical junction abnormalities, spinal cord trauma, and spinal cord tumors. Symptoms include flaccid weakness of the hands and arms and deficits in pain and temperature sensation in a capelike distribution over the back and neck; light touch and position and vibration sensation are not affected. Diagnosis is by MRI. Treatment includes correction of the cause and surgical procedures to drain the syrinx or otherwise open CSF flow.
Syrinxes usually result from lesions that partially obstruct CSF flow. At least ½ of syrinxes occur in patients with congenital abnormalities of the craniocervical junction (eg, herniation of cerebellar tissue into the spinal canal, called Chiari malformation), brain (eg, encephalocele), or spinal cord (eg, myelomeningocele). For unknown reasons, these congenital abnormalities often expand during the teen or young adult years. A syrinx can also develop in patients who have a spinal cord tumor, scarring due to previous spinal trauma, or no known predisposing factors. About 30% of people with a spinal cord tumor eventually develop a syrinx.
Syringomyelia is a paramedian, usually irregular, longitudinal cavity. It commonly begins in the cervical area but may extend downward along the entire length of the spinal cord. Syringobulbia, which is rare, usually occurs as a slitlike gap within the lower brain stem and may disrupt or compress the lower cranial nerves or ascending sensory or descending motor pathways.
Symptoms and Signs
Symptoms usually begin insidiously between adolescence and age 45. Syringomyelia develops in the center of the spinal cord, causing a central cord syndrome Pain and temperature sensory deficits occur early but may not be recognized for years. The first abnormality recognized may be a painless burn or cut. Syringomyelia typically causes weakness, atrophy, and often fasciculations and hyporeflexia of the hands and arms; a deficit in pain and temperature sensation in a capelike distribution over the shoulders, arms and back is characteristic. Light touch and position and vibration sensation are not affected. Later, spastic leg weakness develops. Deficits may be asymmetric.
Syringobulbia may cause vertigo, nystagmus, unilateral or bilateral loss of facial sensation, lingual atrophy and weakness, dysarthria, dysphagia, hoarseness, and sometimes peripheral sensory or motor deficits due to medullary compression.
Diagnosis and Treatment
A syrinx is suggested by an unexplained central cord syndrome or other characteristic neurologic deficits, particularly pain and temperature sensory deficits in a capelike distribution. MRI of the entire spinal cord and brain is done. Gadolinium enhancement is useful for detecting any associated tumor.
Underlying problems (eg, craniocervical junction abnormalities, postoperative scarring, spinal tumors) are corrected when possible. Surgical decompression of the foramen magnum and upper cervical cord is the only useful treatment, but surgery usually cannot reverse severe neurologic deterioration.
Tropical Spastic Paraparesis/HTLV-1–Associated Myelopathy
Tropical spastic paraparesis/HTLV-1–associated myelopathy is a slowly progressive viral immune-mediated disorder of the spinal cord caused by the human T-lymphotrophic virus 1 (HTLV-1). It produces spastic weakness of both legs. Diagnosis is by serologic and PCR tests of serum and CSF. Treatment includes supportive care and possibly immunosuppressive therapies.
The human T-lymphotrophic virus 1 (HTLV-1) retrovirus is transmitted via sexual contact, IV drug use, exposure to infected blood, or from mother to child, via breastfeeding. It is most common among prostitutes, IV drug users, hemodialysis patients, and people from endemic areas such as equatorial regions, southern
The virus resides in T cells in blood and CSF. CD4+ memory T cells, CD8+ cytotoxic T cells, and macrophages infiltrate the perivascular areas and parenchyma of the spinal cord; astrocytosis occurs. For several years after onset of neurologic symptoms, inflammation of spinal gray and white matter progresses, causing preferential degeneration of the lateral and posterior columns. Myelin and axons in the anterior columns are also lost.
Spastic weakness develops gradually in both legs, with extensor plantar responses and bilateral symmetric loss of position and vibratory sensation in the feet. Achilles tendon reflexes are often absent. Urinary incontinence and urgency are common. Symptoms usually progress over several years.
Diagnosis and Treatment
The disorder is suggested by typical neurologic deficits that are otherwise unexplained, particularly in patients with risk factors. Serum and CSF serologic tests, PCR tests, and spinal cord MRI are indicated. If CSF-to-serum ratio of HTLV-1 antibodies is > 1 or if PCR detects HTLV-1 antigen in CSF, the diagnosis is very likely. Protein and Ig levels in CSF may also be elevated, often with oligoclonal bands; lymphocytic pleocytosis occurs in up to 50% of patients. Spinal cord lesions often appear hyperintense on T2-weighted MRI.
No treatment has proved effective, but interferon-α, IV immune globulin, and oral methylprednisolone Some Trade Names
MEDROL
may have some benefit. Treatment of spasticity is symptomatic (eg, with baclofen Some Trade Names
LIORESAL
or tizanidine Some Trade Names
ZANAFLEX
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