Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
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.
Vascular myelopathy (vascular disease of the spinal cord) refers to an abnormality of the spinal cord in regard to its blood supply. The blood supply is complicated and supplied by two major vessel groups: the posterior spinal arteries and the anterior spinal arteries—of which the Artery of Adamkiewicz is the largest. Both the posterior and anterior spinal arteries run the entire length of the spinal cord and receive anastomotic (conjoined) vessels in many places. The anterior spinal artery has a less efficient supply of blood and is therefore more susceptible to vascular disease. Whilst atherosclerosis of spinal arteries is rare, necrosis (death of tissue) in the anterior artery can be caused by disease in vessels originating from the segmental arteries such as atheroma (arterial wall swelling) or aortic dissection (a tear in the aorta).
Potential non-surgical treatments include:
- Education about the course of the condition and how to relieve symptoms
- Medicines to relieve pain and inflammation, such as acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs)
- Exercise, to maintain or achieve overall good health, aerobic exercise, such as riding a stationary bicycle, which allows for a forward lean, walking, or swimming can relieve symptoms
- Weight loss, to relieve symptoms and slow progression of the stenosis
- Physical therapy, to provide education, instruction, and support for self-care; physical therapy instructs on stretching and strength exercises that may lead to a decrease in pain and other symptoms
The evidence for the use of medical interventions for lumbar spinal stenosis is poor. Injectable but not nasal calcitonin may be useful for short term pain relief. Epidural blocks may also transiently decrease pain, but there is no evidence of long-term effect. Adding steroids to these injections does not improve the result; the use of epidural steroid injections (ESIs) is controversial and evidence of their efficacy is contradictory.
Non-steroidal anti-inflammatory drugs (NSAIDs), muscle relaxants and opioid analgesics are often used to treat low back pain, but evidence of their efficacy is lacking.
Nonoperative therapies and laminectomy are the standard treatment for LSS. A trial of conservative treatment is typically recommended. Individuals are generally advised to avoid stressing the lower back, particularly with the spine extended. A physical therapy program to provide core strengthening and aerobic conditioning may be recommended. Overall scientific evidence is inconclusive on whether conservative approach or a surgical treatment is better for lumbar spinal stenosis.
Treatment is determined based on the primary cause of anterior cord syndrome. When the diagnosis of anterior cord syndrome is determined, the prognosis is unfortunate. The mortality rate is approximately 20%, with 50% of individuals living with anterior cord syndrome having very little or no changes in symptoms.
Treatment options are either surgical or non-surgical. Overall evidence is inconclusive whether non-surgical or surgical treatment is the better for lumbar spinal stenosis.
The effectiveness of non surgical treatments is unclear as they have not been well studied.
- Education about the course of the condition and how to relieve symptoms
- Medicines to relieve pain and inflammation, such as acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs)
- Exercise, to maintain or achieve overall good health, aerobic exercise, such as riding a stationary bicycle, which allows for a forward lean, walking, or swimming can relieve symptoms
- Weight loss, to relieve symptoms and slow progression of the stenosis
- Physical therapy to support self-care. Also may give instructs on stretching and strength exercises that may lead to a decrease in pain and other symptoms.
- Lumbar epidural steroid or anesthetic injections have low quality evidence to support their use.
Potential surgical treatments include:
- Anterior cervical discectomy and fusion - A surgical treatment of nerve root or spinal cord compression by decompressing the spinal cord and nerve roots of the cervical spine with a discectomy in order to stabilize the corresponding vertebrae.
- Laminoplasty - A surgical procedure relieve pressure on the spinal cord by cutting the lamina on both sides of the affected vertebrae (cutting through on one side and merely cutting a groove on the other) and then "swinging" the freed flap of bone open.
- Laminectomy - A surgical procedure in which the lamina of the vertebra is removed or trimmed to widen the spinal canal and create more space for the spinal nerves and thecal sac.
Surgical intervention is usually given to those individuals who have increased instability of their cervical spine, which cannot be resolved by conservative management alone. Further indications for surgery include a neurological decline in spinal cord function in stable patients as well as those who require cervical spinal decompression.
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.
Dexamethasone (a potent glucocorticoid) in doses of 16 mg/day may reduce edema around the lesion and protect the cord from injury. It may be given orally or intravenously for this indication.
Surgery is indicated in localised compression as long as there is some hope of regaining function. It is also occasionally indicated in patients with little hope of regaining function but with uncontrolled pain. Postoperative radiation is delivered within 2–3 weeks of surgical decompression. Emergency radiation therapy (usually 20 Gray in 5 fractions, 30 Gray in 10 fractions or 8 Gray in 1 fraction) is the mainstay of treatment for malignant spinal cord compression. It is very effective as pain control and local disease control. Some tumours are highly sensitive to chemotherapy (e.g. lymphomas, small-cell lung cancer) and may be treated with chemotherapy alone.
Once complete paralysis has been present for more than about 24 hours before treatment, the chances of useful recovery are greatly diminished, although slow recovery, sometimes months after radiotherapy, is well recognised.
The median survival of patients with metastatic spinal cord compression is about 12 weeks, reflecting the generally advanced nature of the underlying malignant disease.
Because neurological deficits are generally irreversible, early surgery is recommended when symptoms begin to worsen. In children, early surgery is recommended to prevent further neurological deterioration, including but not limited to chronic urinary incontinence.
In adults, surgery to detether (free) the spinal cord can reduce the size and further development of cysts in the cord and may restore some function or alleviate other symptoms. Although detethering is the common surgical approach to TCS, another surgical option for adults is a spine-shortening vertebral osteotomy. A vertebral osteotomy aims to indirectly relieve the excess tension on the spinal cord by removing a portion of the spine, shortening it. This procedure offers a unique benefit in that the spinal cord remains fixated to the spine, preventing retethering and spinal cord injury as possible surgical complications. However, its complexity and limited “track record” presently keeps vertebral osteotomies reserved as an option for patients who have failed in preventing retethering after detethering procedure(s).
Other treatment is symptomatic and supportive. Medications such as NSAIDs, opiates, synthetic opiates, COX-2 inhibitors, and off-label applications of tricyclic antidepressants combined with anti-seizure compounds have yet to prove they are of value in treatment of this affliction's pain manifestations. There is anecdotal evidence that TENS units may benefit some patients.
Treatment may be needed in adults who, while previously asymptomatic, begin to experience pain, lower back degeneration, scoliosis, neck and upper back problems and bladder control issues. Surgery on adults with minimal symptoms is somewhat controversial. For example, a website from the Columbia University Department of Neurosurgery says, "For the child that has reached adult height with minimal if any symptoms, some neurosurgeons would advocate careful observation only." However, surgery for those who have worsening symptoms is less controversial. If the only abnormality is a thickened, shortened filum, then a limited lumbosacral laminectomy with division of the filum may be sufficient to relieve the symptoms.
This syndrome was first noticed in the late 19th century. While information has been available for years, little widespread blind research has been done. More research has been called for, and doctors have conducted many studies with good results. There is a low morbidity rate, and no complications have been documented other than those typical of any type of back surgery. The association of this condition with others has been noticed, and needs further research to understand such relationships. TCS is causally linked to Chiari malformation and any affirmative diagnosis of TCS must be followed by screening for Chiari's several degrees. TCS may also be related to Ehlers-Danlos syndrome, or Klippel-Feil syndrome, which should also be screened for upon a positive TCS diagnosis. Spinal compression and the resulting relief is a known issue with this disorder. Like with the early-onset form, this disease form is linked to the Arnold-Chiari malformation, in which the brain is pulled or lowers into the top of the spine.
A 69-year-old male with tethered cord that was low lying and associated with Spina Bifida in the form of meningocele that was operated on as an infant, was studied in this research. He presented with worsened neurological deficits due to progressive lumbar stenosis at the L3-L4 level which was associated with the spinal discs degenerating. Extreme lateral inter body fusion (XLIF) was performed to allow for indirect spinal cord decompression and stability which allowed for neurological improvement. The role of the XLIF approach to this treatment was emphasized and compared to other surgical approaches. It was concluded that surgical decompression should be performed as soon as possible to prevent any further neurological damage. Also concluded was that the XLIF approach is safe and fast and is indicative of a good surgical option to obtain spinal cord indirect decompression and lumbar inter body fusion.
In many cases, individuals with CCS can experience a reduction in their neurological symptoms with conservative management. The first steps of these intervention strategies include admission to an intensive care unit (ICU) after initial injury. After entering the ICU, early immobilization of the cervical spine with a neck collar would be placed on the patient to limit the potential of further injury. Cervical spine restriction is maintained for approximately six weeks until the individual experiences a reduction in pain and neurological symptoms. Inpatient rehabilitation is initiated in the hospital setting, followed by outpatient physical therapy and occupational therapy to assist with recovery.
An individual with a spinal cord injury may have many goals for outpatient occupational and physiotherapy. Their level of independence, self-care, and mobility are dependent on their degree of neurological impairment. Rehabilitation organization and outcomes are also based on these impairments. The physiatrist, along with the rehabilitation team, work with the patient to develop specific, measurable, action-oriented, realistic, and time-centered goals.
With respect to physical therapy interventions, it has been determined that repetitive task-specific sensory input can improve motor output in patients with central cord syndrome. These activities enable the spinal cord to incorporate both supraspinal and afferent sensory information to help recover motor output. This occurrence is known as "activity dependent plasticity". Activity dependant plasticity is stimulated through such activities as: locomotor training, muscle strengthening, voluntary cycling, and functional electrical stimulation (FES) cycling
The treatment and prognosis of myelopathy depends on the underlying cause: myelopathy caused by infection requires medical treatment with pathogen specific antibiotics. Similarly, specific treatments exist for multiple sclerosis, which may also present with myelopathy. As outlined above, the most common form of myelopathy is secondary to degeneration of the cervical spine. Newer findings have challenged the existing controversy with respect to surgery for cervical spondylotic myelopathy by demonstrating that patients benefit from surgery.
There is no known treatment to reverse nerve damage due to myelomalacia. In some cases, surgery may slow or stop further damage. As motor function degenerates, muscle spasticity and atrophy may occur. Steroids may be prescribed to reduce swelling of the spinal cord, pain, and spasticity.
Research is underway to consider the potential of stem cells for treatment of neurodegenerative diseases. There are, however, no approved stem cell therapies for myelomalacia.
Surgery
Surgical intervention is warranted in patients who present with new onset neurological signs and symptoms or have a history of progressive neurological manifestations which can be related to this abnormality. The surgical procedure required for the effective treatment of diastematomyelia includes decompression (surgery) of neural elements and removal of bony spur. This may be accomplished with or without resection and repair of the duplicated dural sacs. Resection and repair of the duplicated dural sacs is preferred since the dural abnormality may partly contribute to the "tethering" process responsible for the symptoms of this condition.
Post-myelographic CT scanning provides individualized detailed maps that enable surgical treatment of cervical diastematomyelia, first performed in 1983.
Observation
Asymptomatic patients do not require surgical treatment. These patients should have regular neurological examinations since it is known that the condition can deteriorate. If any progression is identified, then a resection should be performed.
Medial medullary syndrome, also known as inferior alternating syndrome, hypoglossal alternating hemiplegia, lower alternating hemiplegia, or Dejerine syndrome, is a type of alternating hemiplegia characterized by a set of clinical features resulting from occlusion of the anterior spinal artery. This results in the infarction of medial part of the medulla oblongata.
Foix–Alajouanine syndrome is a disorder caused by an arteriovenous malformation of the spinal cord. The patients present with symptoms indicating spinal cord involvement (paralysis of arms and legs, numbness and loss of sensation and sphincter dysfunction), and pathological examination reveals disseminated nerve cell death in the spinal cord and abnormally dilated and tortuous vessels situated on the surface of the spinal cord. Surgical treatment can be tried in some cases. If surgical intervention is contraindicated, corticosteroids may be used.
The condition is named after Charles Foix and Théophile Alajouanine.
Treatment is directed at the pathology causing the paralysis. If it is because of trauma such as a gunshot or knife wound, there may be other life-threatening conditions such as bleeding or major organ damage which should be dealt with on an emergent basis. If the syndrome is caused by a spinal fracture, this should be identified and treated appropriately. Although steroids may be used to decrease cord swelling and inflammation, the usual therapy for spinal cord injury is expectant.
If there aren't neurological symptoms (such as difficulties moving, loss of sensation, confusion, etc.) and there is no evidence of pressure on the spinal cord, a conservative approach may be taken such as:
- Drugs, such as aspirin, without steroids to relieve inflammation
- Cervical traction, in which the neck is pulled along its length, thus relieving pressure on the spinal cord
- Using a neck collar or cervical-thoracic suit
If there is pressure on the spinal cord or life-threatening symptoms are present, surgery is recommended.
Vehicle-related SCI is prevented with measures including societal and individual efforts to reduce driving under the influence of drugs or alcohol, distracted driving, and drowsy driving. Other efforts include increasing road safety (such as marking hazards and adding lighting) and vehicle safety, both to prevent accidents (such as routine maintenance and antilock brakes) and to mitigate the damage of crashes (such as head restraints, air bags, seat belts, and child safety seats). Falls can be prevented by making changes to the environment, such as nonslip materials and grab bars in bathtubs and showers, railings for stairs, child and safety gates for windows. Gun-related injuries can be prevented with conflict resolution training, gun safety education campaigns, and changes to the technology of guns (such as trigger locks) to improve their safety. Sports injuries can be prevented with changes to sports rules and equipment to increase safety, and education campaigns to reduce risky practices such as diving into water of unknown depth or head-first tackling in association football.
Brown-Séquard syndrome is rare as the trauma would have to be something that damaged the nerve fibres on just one half of the spinal cord.
Scientists are investigating various avenues for treatment of spinal cord injury. Therapeutic research is focused on two main areas: neuroprotection and neuroregeneration. The former seeks to prevent the harm that occurs from secondary injury in the minutes to weeks following the insult, and the latter aims to reconnect the broken circuits in the spinal cord to allow function to return. Neuroprotective drugs target secondary injury effects including inflammation, damage by free radicals, excitotoxicity (neuronal damage by excessive glutamate signaling), and apoptosis (cell suicide). Several potentially neuroprotective agents that target pathways like these are under investigation in human clinical trials.
Stem cell transplantation is an important avenue for SCI research: the goal is to replace lost spinal cord cells, allow reconnection in broken neural circuits by regrowing axons, and to create an environment in the tissues that is favorable to growth. A key avenue of SCI research is research on stem cells, which can differentiate into other types of cells—including those lost after SCI. Types of cells being researched for use in SCI include embryonic stem cells, neural stem cells, mesenchymal stem cells, olfactory ensheathing cells, Schwann cells, activated macrophages, and induced pluripotent stem cells. Hundreds of stem cell studies have been done in humans, with promising but inconclusive results. An ongoing Phase 2 trial in 2016 presented data showing that after 90 days, 2 out of 4 subjects had already improved two motor levels and had thus already achieved its endpoint of 2/5 patients improving two levels within 6–12 months. Six-month data is expected in January 2017.
Another type of approach is tissue engineering, using biomaterials to help scaffold and rebuild damaged tissues. Biomaterials being investigated include natural substances such as collagen or agarose and synthetic ones like polymers and nitrocellulose. They fall into two categories: hydrogels and nanofibers. These materials can also be used as a vehicle for delivering gene therapy to tissues.
One avenue being explored to allow paralyzed people to walk and to aid in rehabilitation of those with some walking ability is the use of wearable powered robotic exoskeletons. The devices, which have motorized joints, are put on over the legs and supply a source of power to move and walk. Several such devices are already available for sale, but investigation is still underway as to how they can be made more useful.