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Posterior spinal artery syndrome is much rarer than its anterior counterpart as the white matter structures that are present are much less vulnerable to ischemia since they have a better blood supply. When posterior spinal artery syndrome does occur, dorsal columns are damaged and ischemia may spread into the posterior horns. Clinically the syndrome presents as a loss of tendon reflexes and loss of joint position sense
Anterior spinal artery syndrome is necrosis of tissue in the anterior spinal artery or its branches. It is characterised by pain which radiates at onset and sudden quadraplegia (paralysis of all four limbs) or paraplegia (paralysis of the lower body). Within days, flaccid limbs become spastic and hyporeflexia (underactive nerve responses) turns into hyperreflexia (overactive nerve responses) and extensor plantar nerve responses. Sensory loss to pain and temperature also occurs up to the level of damage on the spinal cord, as damage to different areas will affect different parts of the body.
In diagnosis, other causes of abrupt paralysis should be excluded such as cord compression, transverse myelitis (inflammation of the spinal cord) and Guillain–Barré syndrome. A specific cause of the infarction should be looked for, such as diabetes, polyarteritis nodosa (inflammatory damage of vessels) or systemic lupus erythematosus. Neurosyphilis is also a known cause. Other causes include:
Treatment is supportive and aims to relieve symptoms. The prognosis is dependent upon individual circumstances and factors.
Symptoms usually occur very quickly and are often experienced within one hour of the initial damage. MRI can detect the magnitude and location of the damage 10–15 hours after the initiation of symptoms. Diffusion-weighted imaging may be used as it is able to identify the damage within a few minutes of symptomatic onset.
Clinical features include paraparesis or quadriparesis (depending on the level of the injury) and impaired pain and temperature sensation. Complete motor paralysis below the level of the lesion due to interruption of the corticospinal tract, and loss of pain and temperature sensation at and below the level of the lesion. Proprioception and vibratory sensation is preserved, as it is in the dorsal side of the spinal cord.
Anterior spinal artery syndrome (also known as "anterior spinal cord syndrome", or "Beck's syndrome") is a medical condition where the anterior spinal artery, the primary blood supply to the anterior portion of the spinal cord, is interrupted, causing ischemia or infarction of the spinal cord in the anterior two-thirds of the spinal cord and medulla oblongata. It is characterized by loss of motor function below the level of injury, loss of sensations carried by the anterior columns of the spinal cord (pain and temperature), and preservation of sensations carried by the posterior columns (fine touch, vibration and proprioception). Anterior spinal artery syndrome is the most common form of spinal cord infarction.
Spinal cord injuries at the cervical (neck) level result in full or partial tetraplegia (also called quadriplegia). Depending on the specific location and severity of trauma, limited function may be retained.
Additional signs and symptoms of cervical injuries include low heart rate, low blood pressure, problems regulating body temperature, and breathing dysfunction. If the injury is high enough in the neck to impair the muscles involved in breathing, the person may not be able to breathe without the help of an endotracheal tube and mechanical ventilator.
Central cord syndrome, almost always resulting from damage to the cervical spinal cord, is characterized by weakness in the arms with relative sparing of the legs, and spared sensation in regions served by the sacral segments. There is loss of sensation of pain, temperature, light touch, and pressure below the level of injury. The spinal tracts that serve the arms are more affected due to their central location in the spinal cord, while the corticospinal fibers destined for the legs are spared due to their more external location. The most common of the incomplete SCI syndromes, central cord syndrome usually results from neck hyperextension in older people with spinal stenosis. In younger people, it most commonly results from neck flexion. The most common causes are falls and vehicle accidents; however other possible causes include spinal stenosis and impingement on the spinal cord by a tumor or vertebral disk.
The onset of myelomalacia may be so subtle that it is overlooked. Depending on the extent of the spinal cord injury, the symptoms may vary. In some cases, the symptom may be as common as hypertension. Though every case is different, several cases reported loss of motor functions in the extremities, areflexia or sudden jerks of the limbs, loss of pain perception, or even paralysis; all of which are possible indicators of a damaged and softened spinal cord. In the most severe cases, paralysis of the respiratory system manifests in death.
Clinical signs and symptoms depend on which spinal cord level (cervical, thoracic or lumbar) is affected and the extent (anterior, posterior or lateral) of the pathology, and may include:
- upper motor neuron signs—weakness, spasticity, clumsiness, altered tonus, hyperreflexia and pathological reflexes, including Hoffmann's sign and inverted Plantar reflex (positive Babinski sign);
- lower motor neuron signs—weakness, clumsiness in the muscle group innervated at the level of spinal cord compromise, muscle atrophy, hyporeflexia, muscle hypotonicity or flaccidity, fasciculations;
- sensory deficits;
- bowel/bladder symptoms and sexual dysfunction.
There are disturbances in sensory nerves and motor nerves and dysfunction of the autonomic nervous system at the level of the lesion or below. Therefore, the signs and symptoms depend on the area of spine involved:
- Cervical: If the upper cervical cord is involved, all four limbs may be involved and there is risk of respiratory paralysis (cervical nerve segments C3, 4, 5 innervate the abdominal diaphragm). Lesions of the lower cervical (C5–T1) region will cause a combination of upper and lower motor neuron signs in the upper limbs, and exclusively upper motor neuron signs in the lower limbs. Cervical lesions account for about 20% of cases.
- Thoracic: A lesion of the thoracic spinal cord (T1–12) will produce upper motor neuron signs in the lower limbs, presenting as a spastic diplegia. This is the most common location of the lesion,
Myelomalacia is a pathological term referring to the softening of the spinal cord. Hemorrhagic infarction (bleeding) of the spinal cord can occur as a sequela to acute injury, such as that caused by intervertebral disc extrusion (being forced or pressed out).
The disorder causes flaccid paraplegia (impairment of motor function in lower extremities), total areflexia (below normal or absence of reflexes) of the pelvic limbs and anus, loss of deep pain perception caudal (toward the coccyx, or tail) to the site of spinal cord injury, muscular atrophy (wasting away of muscle tissue), depressed mental state, and respiratory difficulty due to intercostal (muscles that run between the ribs) and diaphragmatic paralysis. Gradual cranial migration of the neurological deficits (problems relating to the nervous system), is known as ascending syndrome and is said to be a typical feature of diffuse myelomalacia. Although clinical signs of myelomalacia are observed within the onset (start) of paraplegia, sometimes they may become evident only in the post-operative period, or even days after the onset of paraplegia. Death from myelomalacia may occur as a result of respiratory paralysis when the ascending lesion (abnormal damaged tissue) reaches the motor nuclei of the phrenic nerves (nerves between the C3-C5 region of the spine) in the cervical (neck) region.
Severe back pain, saddle anesthesia, incontinence and sexual dysfunction are considered "red flags", i.e. features which require urgent investigation.
Cauda equina syndrome (CES) is symptoms due to damage to the bundle of nerves below the end of the spinal cord known as the cauda equina. Symptoms include, low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.
The cause is usually a disc herniation in the lower region of the back. Other causes include spinal stenosis, cancer, trauma, epidural abscess, and epidural hematoma. Diagnosis is often by medical imaging such as MRI or CT scan.
Treatment is generally by urgent surgery in the form of a laminectomy. Some people are left with ongoing bladder problems, sexual dysfunction, or numbness. A poor outcome occurs in about 20% of people despite treatment. About 1 in 70,000 people is affected a year. It was first described in 1934.
Myelopathy describes any neurologic deficit related to the spinal cord. When due to trauma, it is known as (acute) spinal cord injury. When inflammatory, it is known as myelitis. Disease that is vascular in nature is known as vascular myelopathy. The most common form of myelopathy in human, "cervical spondylotic myelopathy (CSM)", is caused by arthritic changes (spondylosis) of the cervical spine, which result in narrowing of the spinal canal (spinal stenosis) ultimately causing compression of the spinal cord. In Asian populations, spinal cord compression often occurs due to a different, inflammatory process affecting the posterior longitudinal ligament.
Understanding the meaning of signs and symptoms for the clinical syndrome of lumbar stenosis requires an understanding of what the syndrome is, and the prevalence of the condition. A recent review on lumbar stenosis in the Journal of the American Medical Association's "Rational Clinical Examination Series" emphasized that the syndrome can be considered when lower extremity pain occurs in combination with back pain. This syndrome occurs in 12% of older community dwelling men and up to 21% of those in retirement communities.
The leg symptoms in lumbar spinal stenosis (LSS) are similar to those found with vascular claudication, giving rise to the term pseudoclaudication. These symptoms include pain, weakness, and tingling of the legs, which may radiate down the leg to the feet. Additional symptoms in the legs may be fatigue, heaviness, weakness, a sensation of tingling, pricking, or numbness and leg cramps, as well as bladder symptoms. Symptoms are most commonly bilateral and symmetrical, but they may be unilateral; leg pain is usually more troubling than back pain.
Pseudoclaudication, now referred to as neurogenic claudication, typically worsen with standing or walking and improve with sitting. The occurrence is often related to posture and lumbar extension. Lying on the side is often more comfortable than lying flat, since it permits greater lumbar flexion. Vascular claudication can resemble spinal stenosis, and some individuals experience unilateral or bilateral symptoms radiating down the legs rather than true claudication.
The first symptoms of stenosis include bouts of low back pain. After a few months or years, this may progress to claudication. The pain may be radicular, following the classic neurologic pathways. This occurs as the spinal nerves or spinal cord become increasingly trapped in a smaller space within the canal. It can be difficult to determine whether pain in the elderly is caused by lack of blood supply or stenosis; testing can usually differentiate between them but patients can have both vascular disease in the legs and spinal stenosis.
Among people with lower extremity pain in combination with back pain, lumbar stenosis as the cause is two times more likely in those older than 70 years of age while those younger than 60 years it is 0.40 as likely. The character of the pain is also useful. When the discomfort does not occur while seated, the likelihood of LSS increases considerably around 7.4 times. Other features increasing the likelihood of lumbar stenosis are improvement in symptoms on bending forward 6.4 times, pain that occurs in both buttocks or legs 6.3 times, and the presence of neurogenic claudication 3.7 times. Alternately, the absence of neurogenic claudication makes lumbar stenosis much less likely as the explanation for the pain.
Syringomyelia causes a wide variety of neuropathic symptoms due to damage of the spinal cord and the nerves inside. Patients may experience severe chronic pain, abnormal sensations and loss of sensation particularly in the hands. Some patients experience paralysis or paresis temporarily or permanently. A syrinx may also cause disruptions in the parasympathetic and sympathetic nervous systems, leading to abnormal body temperature or sweating, bowel control issues, or other problems. If the syrinx is higher up in the spinal cord or affecting the brainstem as in syringobulbia, vocal cord paralysis, ipsilateral tongue wasting, trigeminal nerve sensory loss, and other signs may occur. Rarely, bladder stones can occur in the onset of weakness in the lower extremities.
Classically, syringomyelia spares the dorsal column/medial lemniscus of the spinal cord, leaving pressure, vibration, touch and proprioception intact in the upper extremities. Neuropathic arthropathy, also known as a Charcot joint, can occur, particularly in the shoulders, in patients with syringomyelia. The loss of sensory fibers to the joint is theorized to lead to damage of the joint over time.
SCIWORA may present as a complete spinal cord injury (total loss of sensation and function below the lesion) or incomplete spinal cord injury (some sensation and/or function is preserved). It is present in a significant number of children with SCI. Notably, the clinical symptoms can present with a delay of hours to days after the trauma. This phenomenon was primarily seen in children but was reported in adults as well. The duration of symptoms varies widely. A full recovery can be achieved without treatment within minutes to hours and permanent injuries might prevail. Overall, there seems to be a relation between extent of damage to the spinal cord and the clinical prognosis. The prognostic value of intra- and extra-medullary MRI findings is subject of ongoing research in the field of SCIWORA.
Arachnoid inflammation can lead to many painful and debilitating symptoms which can vary greatly in each case, and not all people experience all symptoms. Chronic pain is common, including neuralgia, while numbness and tingling of the extremities can occur with spinal cord involvement, and bowel, bladder, and sexual functioning can be affected if the lower part of the spinal cord is involved. While arachnoiditis has no consistent pattern of symptoms, it frequently affects the nerves that supply the legs and lower back. Many patients experience difficulty sitting for long (or even short) periods of time due to discomfort or pain, or because of efferent neurological or other motor symptoms, such as difficulties controlling limbs. Difficulty sitting can be problematic for patients who have trouble standing or walking for long periods, as wheelchairs are not always helpful in such cases.
Symptoms suggestive of cord compression are back pain, a dermatome of increased sensation, paralysis of limbs below the level of compression, decreased sensation below the level of compression, urinary and fecal incontinence and/or urinary retention. Lhermitte's sign (intermittent shooting electrical sensation) and hyperreflexia may be present.
Arachnoiditis is a chronic disorder with no known cure, and prognosis may be hard to determine because of an unclear correlation between the beginning of the disease and the appearance of symptoms. For many, arachnoiditis is a disabling disease that causes chronic pain and neurological deficits, and may also lead to other spinal cord conditions, such as syringomyelia.
Pain is the most common symptom at presentation. The symptoms seen are due to spinal nerve compression and weakening of the vertebral structure. Incontinence and decreased sensitivity in the "saddle area" (buttocks) are generally considered warning signs of spinal cord compression by the tumor. Other symptoms of spinal cord compression include lower extremity weakness, sensory loss, numbness in hands and legs and rapid onset paralysis. The diagnosis of primary spinal cord tumors is very difficult, mainly due to its symptoms, which tend to be wrongly attributed to more common and benign degenerative spinal diseases.
Spinal cord compression is commonly found in patients with metastatic malignancy. Back pain is a primary symptom of spinal cord compression in patients with known malignancy. It may prompt a bone scan to confirm or exclude spinal metastasis. Rapid identification and intervention of malignant spinal tumors, often causing spinal cord compression, is key to maintaining quality of life in patients.
Depending on the cause of the disease, such clinical conditions manifest different speed in progression of symptoms in a matter of hours to days. Most myelitis manifests fast progression in muscle weakness or paralysis starting with the legs and then arms with varying degrees of severity. Sometimes the dysfunction of arms or legs cause instability of posture and difficulty in walking or any movement. Also symptoms generally include paresthesia which is a sensation of tickling, tingling, burning, pricking, or numbness of a person's skin with no apparent long-term physical effect. Adult patients often report pain in the back, extremities, or abdomen. Patients also present increased urinary urgency, bowel or bladder dysfunctions such as bladder incontinence, difficulty or inability to void, and incomplete evacuation of bowel or constipation. Others also report fever, respiratory problems and intractable vomiting.
CCS is characterized by disproportionately greater motor impairment in upper compared to lower extremities, and variable degree of sensory loss below the level of injury in combination with bladder dysfunction and urinary retention. This syndrome differs from that of a complete lesion, which is characterized by total loss of all sensation and movement below the level of the injury.
The application of MRI plays a significant role in the early diagnosis and treatment of SCIWORA in children and adults. Recently, systematic reviews on SCIWORA described the clinical and radiological patterns and correlations with neurological outcome.C.K. Boese und P. Lechler: "Spinal cord injury without radiologic abnormalities in adults: a systematic review." In: "Journal of Trauma and Acute Care Surgery." 78, 2015, S. 320-330 .Boese CK, Oppermann J, Siewe J, Eysel P, Scheyerer MJ, Lechler P.: "Spinal cord injury without radiologic abnormality in children: a systematic review and meta-analysis." In: "Journal of Trauma and Acute Care Surgery." 75, 2013. Boese and Lechler proposed a MRI-based classification for SCIWORA which correlated with the neurological outcome:
Transverse myelitis is a neurological condition in which the spinal cord is inflamed. The inflammation damages nerve fibers, and causes them to lose their myelin coating leading to decreased electrical conductivity in the central nervous system. "Transverse" implies that the inflammation extends across the entire width of the spinal cord. Partial transverse myelitis and partial myelitis are terms used to define inflammation of the spinal cord that affects part of the width of the spinal cord.
Myelitis lesions usually occur in a narrow region but can be spread and affect many areas.
- Poliomyelitis: disease caused by viral infection in the gray matter with symptoms of muscle paralysis or weakness
- Leukomyelitis: lesions in the white matter
- Transverse Myelitis: caused by axonal demyelination encompassing both sides of the spinal cord
- Meningococcal Myelitis (or meningomyelitis): lesions occurring in the region of meninges and the spinal cord