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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
In 1995, the Food and Drug Administration (FDA) approved the Varicella vaccine to prevent chickenpox. Its effect on postherpetic neuralgia is still unknown. The vaccine—made from a weakened form of the varicella-zoster virus—may keep chickenpox from occurring in nonimmune children and adults, or at least lessen the risk of the chickenpox virus lying dormant in the body and reactivating later as shingles. If shingles could be prevented, postherpetic neuralgia could be completely avoided.
In May 2006 the Advisory Committee on Immunization Practices approved a new vaccine by Merck (Zostavax) against shingles. This vaccine is a more potent version of the chickenpox vaccine, and evidence shows that it reduces the incidence of postherpetic neuralgia. The CDC recommends use of this vaccine in all persons over 60 years old.
An April 2013 Cochrane Collaboration meta-analysis of 6 randomized controlled trials (RCTs) investigating oral antiviral medications given within 72 hours after the onset of herpes zoster rash in immunocompetent people for preventing postherpetic neuralgia (PHN) found no significant difference between placebo and acyclovir. Combining four RCTs, 44.1% of the acyclovir treatment group developed herpetic neuralgia whereas 53.3% of the placebo group developed herpetic neuralgia. Heterogeneity between the four RCTs was moderate: Chi =3.36, df = 2 (P=0.19); I = 40%.
Additionally, there was no significant difference in preventing the incidence of PHN found in the one RCT included in the meta-analysis that compared placebo to PO famciclovir treatment within 72 hours of HZ rash onset. Studies using valaciclovir treatment were not included in the meta-analysis.
PHN was defined as pain at the site of the dermatomic rash at 120 days after the onset of rash, and incidence was evaluated at 1, 4, and 6 months after rash onset.
There was a slight reduction in the incidence of pain at 4 weeks after the onset of rash in the aciclovir group (153 study participants with pain out of 347 study participants in the aciclovir group) versus the placebo group (184 study participants with pain out of 345 study participants in the placebo group). Patients who are prescribed PO antiviral agents after the onset of rash should be informed that their chances of developing PHN are no different than those not taking PO antiviral agents.
A randomized controlled trial found that amitriptyline 25 mg per night for 90 days starting within two days of onset of rash can reduce the incidence of postherpetic neuralgia from 35% to 16% (number needed to treat is 6).
A variety of surgeries have been performed including microvascular decompression (MVD) of the fifth, ninth, and tenth nerves; as well as partial cutting of the nervus intermedius, geniculate ganglion, chorda tympani and/or the ninth and tenth cranial nerves.
A trial of the anticonvulsant drug carbamazepine is common for patients diagnosed with GN. For patients who do not tolerate or respond to carbamazepine, alternative drugs include oxcarbazepine, gabapentin, phenytoin, lamotrigine, and baclofen. In addition, tricyclics (e.g., amitriptyline) and pregabalin are useful in other types of neuropathic pain.
Psychological and social support has found to play a key role in the management of chronic illnesses and chronic pain conditions, such as trigeminal neuralgia. Chronic pain can cause constant frustration to an individual as well as to those around them. As a result, there are many advocacy groups.
All destructive procedures will cause facial numbness, post relief, as well as pain relief.
- Percutaneous techniques which all involve a needle or catheter entering the face up to the origin where the nerve splits into three divisions and then damaging this area, purposely, to produce numbness but also stop pain signals. These techniques are proven effective especially in those where other interventions have failed or in those who are medically unfit for surgery such as the elderly.
- Balloon compression - inflation of a balloon at this point causing damage and stopping pain signals.
- Glycerol injection- deposition of a corrosive liquid called glycerol at this point causes damage to the nerve to hinder pain signals.
- Radiofrequency thermocoagulation rhizotomy - application of a heated needle to damage the nerve at this point.
- Stereotactic radiosurgery is a form of radiation therapy that focuses high-power energy on a small area of the body
Treatment of people believed to have ATN or TN is usually begun with medication. The long-time first drug of choice for facial neuralgia has been carbamazepine, an anti-seizure agent. Due to the significant side-effects and hazards of this drug, others have recently come into common use as alternatives. These include oxcarbazepine, lamotrigine, and gabapentin. A positive patient response to one of these medications might be considered as supporting evidence for the diagnosis, which is otherwise made from medical history and pain presentation. There are no present medical tests to conclusively confirm TN or ATN.
If the anti-seizure drugs are found ineffective, one of the tricyclic antidepressant medications such as amitriptyline or nortriptyline, may be used. The tricyclic antidepressants are known to have dual action against both depression and neuropathic pain. Other drugs which may also be tried, either individually or in combination with an anti-seizure agent, include baclofen, pregabalin, anti-seizure drugs (to calm nerve endings), muscle relaxants, and opioid drugs such as oxycodone or an oxycodone/paracetamol combination.
For some people with ATN opioids may represent the only viable medical option which preserves quality of life and personal functioning. Although there is considerable controversy in public policy and practice in this branch of medicine, practice guidelines have long been available and published.
If drug treatment is found to be ineffective or causes disabling side effects, one of several neurosurgical procedures may be considered. The available procedures are believed to be less effective with type II (atypical) trigeminal neuralgia than with type I (typical or "classic") TN. Among present procedures, the most effective and long lasting has been found to be microvascular decompression (MVD), which seeks to relieve direct compression of the trigeminal nerve by separating and padding blood vessels in the vicinity of the emergence of this nerve from the brain stem, below the cranium.
Choice of a surgical procedure is made by the doctor and patient in consultation, based on the patient's pain presentation and health and the doctor's medical experience. Some neurosurgeons resist the application of MVD or other surgeries to atypical trigeminal neuralgia, in light of a widespread perception that ATN pain is less responsive to these procedures. However, recent papers suggest that in cases where pain initially presents as type I TN, surgery may be effective even after the pain has evolved into type II.
The aims of treatment are to limit the severity and duration of pain, shorten the duration of a shingles episode, and reduce complications. Symptomatic treatment is often needed for the complication of postherpetic neuralgia.
However, a study on untreated shingles shows that, once the rash has cleared, postherpetic neuralgia is very rare in people under 50 and wears off in time; in older people the pain wore off more slowly, but even in people over 70, 85% were pain free a year after their shingles outbreak.
People with mild to moderate pain can be treated with over-the-counter pain medications. Topical lotions containing calamine can be used on the rash or blisters and may be soothing. Occasionally, severe pain may require an opioid medication, such as morphine. Once the lesions have crusted over, capsaicin cream (Zostrix) can be used. Topical lidocaine and nerve blocks may also reduce pain. Administering gabapentin along with antivirals may offer relief of postherpetic neuralgia.
Lithium, methysergide, and topiramate are recommended alternative treatments, although there is little evidence supporting the use of topiramate or methysergide. This is also true for tianeptine, melatonin and ergotamine. Valproate, sumatriptan and oxygen are not recommended as preventative measures. Botulinum toxin injections have shown limited success. Evidence for baclofen, botulinum toxin, and capsaicin is unclear.
The other primarily recommended treatment of acute attacks is subcutaneous or intranasal sumatriptan. Sumatriptan and zolmitriptan have both been shown to improve symptoms during an attack with sumatriptan being superior. Because of the vasoconstrictive side-effect of triptans, they may be contraindicated in people with ischemic heart disease.
Hemicrania continua generally responds only to indomethacin 25–300 mg daily, which must be continued long term. Unfortunately, gastrointestinal side effects are a common problem with indomethacin, which may require additional acid-suppression therapy to control.
In patients who are unable to tolerate indomethacin, the use of celecoxib 400–800 mg per day (Celebrex) and rofecoxib 50 mg per day (Vioxx - no longer available) have both been shown to be effective and are likely to be associated with fewer GI side effects. There have also been reports of two patients who were successfully managed with topiramate 100–200 mg per day (Topamax) although side effects with this treatment can also prove problematic.
Greater Occipital Nerve [GON] block comprising 40 mg Depomedrone and 10mls of 1% Lignocaine injected into the affected nerve is effective, up to a period of approximately three months. Changing the 'cocktail' to include [for example] 10mls of .5% Marcaine and changing to 2% Lignocaine, whilst in theory should increase the longevity, renders the injection completely ineffective. See 4.2 Posology and method of administration [flocculation]
Occipital nerve stimulation may be highly effective when other treatments fail to relieve the intractable pain.
Primary headache syndromes have many different possible treatments. In those with chronic headaches the long term use of opioids appears to result in greater harm than benefit.
Numerous compounds alleviate the pain from allodynia. Some are specific for certain types of allodynia while others are general. They include:
- Dynamic mechanical allodynia - compounds targeting different ion channels; opioids
- Mexiletine
- Lidocaine (IV/topical)
- Tramadol
- Morphine (IV)
- Alfentanil (IV)
- Ketamine (IV)
- Methylprednisone (intrathecal)
- Adenosine
- Glycine antagonist
- Desipramine
- Venlafaxine
- Lyrica
- Static mechanical allodynia - sodium channel blockers, opioids
- Lidocaine (IV)
- Alfentanil (IV)
- Adenosine (IV)
- Ketamine (IV)
- Glycine antagonist
- Venlafaxine
- Gabapentin (may also be helpful in cold and dynamic allodynias)
- Cold allodynia
- Lamotrigine
- Lidocaine (IV)
The list of compounds that can be used to treat allodynia is even longer than this. For example, many non-steroidal anti-inflammatory drugs, such as naproxen, can inhibit COX-1 and/or COX-2, thus preventing the sensitization of the central nervous system. Another effect of naproxen is the reduction of the responsiveness of mechano- and thermoreceptors to stimuli.
Other compounds act on molecules important for the transmission of an action potential from one neuron to another. Examples of these include interfering with receptors for neurotransmitters or the enzymes that remove neurotransmitters not bound to receptors.
Endocannabinoids are molecules that can relieve pain by modulating nociceptive neurons. When anandamide, an endocannabinoid, is released, pain sensation is reduced. Anandamide is later transported back to the neurons releasing it using transporter enzymes on the plasma membrane, eventually disinhibiting pain perception. However, this re-uptake can be blocked by AM404, elongating the duration of pain inhibition.
Migraine can be somewhat improved by lifestyle changes, but most people require medicines to control their symptoms. Medications are either to prevent getting migraines, or to reduce symptoms once a migraine starts.
Preventive medications are generally recommended when people have more than four attacks of migraine per month, headaches last longer than 12 hours or the headaches are very disabling. Possible therapies include beta blockers, antidepressants, anticonvulsants and NSAIDs. The type of preventive medicine is usually chosen based on the other symptoms the person has. For example, if the person also has depression, an antidepressant is a good choice.
Abortive therapies for migraines may be oral, if the migraine is mild to moderate, or may require stronger medicine given intravenously or intramuscularly. Mild to moderate headaches should first be treated with acetaminophen (paracetamol) or NSAIDs, like ibuprofen. If accompanied by nausea or vomiting, an antiemitic such as metoclopramide (Reglan) can be given orally or rectally. Moderate to severe attacks should be treated first with an oral triptan, a medication which mimics serotonin (an agonist) and causes mild vasoconstriction. If accompanied by nausea and vomiting, parenteral (through a needle in the skin) triptans and antiemetics can be given.
Several complementary and alternative strategies can help with migraines. The American Academy of Neurology guidelines for migraine treatment in 2000 stated relaxation training, electromyographic feedback and cognitive behavioral therapy may be considered for migraine treatment, along with medications.
Research suggests that people with AFP are not helped greatly by health care professionals. One study reported that on average, individuals had consulted 7.5 different doctors. 91% had seen dentists, 80% physicians, 66% neurologists, 63% ear, nose and throat surgeons, 31% orthopedic and maxillofacial surgeons, 23% psychiatrists, 14% neurosurgeons and 6% ophalmologists and dermatologists. In this study, the individuals had been subjected to a wide variety of different treatments, from surgery, antidepressants, analgesics and physical therapies. None of the persons reported that surgery was beneficial, and in many cases the pain was worsened by surgery. The article sited as the source of this information was withdrawn from publication, saying the information was out of date and not meeting Cochrane methodological standards.
It has been suggested that the onset of chronic facial will likely be a life changing development for those affected.
Psychosocial interventions for AFP include cognitive behavioral therapy and biofeedback. A systematic review reported that there was weak evidence to support the use of these treatments to improve long-term outcomes in chronic orofacial pain, however these results were based primarily upon temporomandibular joint dysfunction and burning mouth syndrome rather than ATP and AO.
Psychosocial interventions assume 2 models of chronic facial pain, namely "inactivity" and "over activity". The former is where people with pain become conditioned to avoid physical activity as a result of exacerbating their pain. These negative thoughts and behaviors in fact prolong and intensify their symptoms. Some psychosocial interventions work on this fear-avoidance behaviour to improve functioning and thereby alleviate symptoms. The over activity model involves factors such as anxiety, depression or anger acting to increase pain by triggering autonomic, visceral and skeletal activity.
Hemicrania was mentioned in 1881 in The Therapeutic Gazette Vol. 2, by G.S.Davis, and the incident has been cited in King's American Dispensatory (1898 and later editions) in the description of the strong analgesic Jamaican Dogwood, a relatively low dose of which reportedly produced convulsions and prolonged respiratory depression over six hours in an elderly woman with this condition.
In newer times, Hemicrania continua was described in 1981; at that time around 130 cases were described in the literature. However, rising awareness of the condition has led to increasingly frequent diagnosis in headache clinics, and it seems that it is not as rare as these figures would imply. The condition occurs more often in women than men and tends to present first in adulthood, although it has also been reported in children as young as 5 years old.
Anesthesia dolorosa or anaesthesia dolorosa or deafferentation pain is pain felt in an area (usually of the face) which is completely numb to touch. The pain is described as constant, burning, aching or severe. It can be a side effect of surgery involving any part of the trigeminal system, and occurs after 1–4% of peripheral surgery for trigeminal neuralgia. No effective medical therapy has yet been found. Several surgical techniques have been tried, with modest or mixed results. The value of surgical interventions is difficult to assess because published studies involve small numbers of mixed patient types and little long term follow-up.
- Gasserian ganglion stimulation is stimulation of the gasserian ganglion with electric pulses from a small generator implanted beneath the skin. There are mixed reports, including some reports of marked, some of moderate and some of no improvement. Further studies of more patients with longer follow-up are required to determine the efficacy of this treatment.
- Deep brain stimulation was found in one review to produce good results in forty-five percent of 106 cases. Though relief may not be permanent, several years of relief may be achieved with this technique.
- Mesencephalotomy is the damaging of the junction of the trigeminal tract and the periaqueductal gray in the brain, and has produced pain relief in a group of patients with cancer pain; but when applied to six anesthesia dolorosa patients, no pain relief was achieved, and the unpleasant sensation was in fact increased.
- Dorsal root entry zone lesioning, damaging the point where sensory nerve fibers meet spinal cord fibers, produced favorable results in some patients and poor results in others, with incidence of ataxia at 40%. Patient numbers were small, follow-up was short and existing evidence does not indicate long term efficacy.
- One surgeon treated thirty-five patients using trigeminal nucleotomy, damaging the nucleus caudalis, and reported 66% "abolition of allodynia and a marked reduction in or (less frequently) complete abolition of deep background pain."
Allodynia is a clinical feature of many painful conditions, such as neuropathies, complex regional pain syndrome, postherpetic neuralgia, fibromyalgia, and migraine. Allodynia may also be caused by some populations of stem cells used to treat nerve damage including spinal cord injury. Static mechanical allodynia is a paradoxical painful hypoaesthesia, one etiology of which is lesions of A-beta fibers.
There are numerous pharmaceutical treatments for neuropathic pain associated with pudendal neuralgia. Drugs used include anti-epileptics (like gabapentin), antidepressants (like amitriptyline), and palmitoylethanolamide.
It is normally possible to establish the cause of ear pain based on the history. It is important to exclude cancer where appropriate, particularly with unilateral otalgia in an adult who uses tobacco or alcohol.Often migraines are caused by middle ear infections which can easily be treated with antibiotics. Often using a hot washcloth can temporarily relieve ear pain.
There are stretches and exercises which have provided reduced levels of pain for some people. There are different sources of pain for people since there are so many ligament, muscles and nerves in the area. Sometimes women do pelvic floor exercises for compression after childbirth. However, there have been cases where the wrong stretches make the constant pain worse. Some people need to strengthen the muscles, others should stretch, while for some people it is purely neurological. There have been cases where doing stretches have helped bicyclists. Acupuncture has helped decrease pain levels for some people, but is generally ineffective. Chiropractic adjustments to the lower back have also helped some patients with pudendal nerve issues.
The management of low back pain often includes medications for the duration that they are beneficial. With the first episode of low back pain the hope is a complete cure; however, if the problem becomes chronic, the goals may change to pain management and the recovery of as much function as possible. As pain medications are only somewhat effective, expectations regarding their benefit may differ from reality, and this can lead to decreased satisfaction.
The medication typically recommended first are NSAIDs (though not aspirin) or skeletal muscle relaxants and these are enough for most people. Benefits with NSAIDs; however, is often small. High-quality reviews have found acetaminophen (paracetamol) to be no more effective than placebo at improving pain, quality of life, or function. NSAIDs are more effective for acute episodes than acetaminophen; however, they carry a greater risk of side effects including: kidney failure, stomach ulcers and possibly heart problems. Thus, NSAIDs are a second choice to acetaminophen, recommended only when the pain is not handled by the latter. NSAIDs are available in several different classes; there is no evidence to support the use of COX-2 inhibitors over any other class of NSAIDs with respect to benefits. With respect to safety naproxen may be best. Muscle relaxants may be beneficial.
If the pain is still not managed adequately, short term use of opioids such as morphine may be useful. These medications carry a risk of addiction, may have negative interactions with other drugs, and have a greater risk of side effects, including dizziness, nausea, and constipation. The effect of long term use is unknown. Specialist groups advise against general long-term use of opioids for chronic low back pain.
For older people with chronic pain, opioids may be used in those for whom NSAIDs present too great a risk, including those with diabetes, stomach or heart problems. They may also be useful for a select group of people with neuropathic pain.
Antidepressants may be effective for treating chronic pain associated with symptoms of depression, but they have a risk of side effects. Although the antiseizure drugs gabapentin and carbamazepine are sometimes used for chronic low back pain and may relieve sciatic pain, there is insufficient evidence to support their use. Systemic oral steroids have not been shown to be useful in low back pain. Facet joint injections and steroid injections into the discs have not been found to be effective in those with persistent, non-radiating pain; however, they may be considered for those with persistent sciatic pain. Epidural corticosteroid injections provide a slight and questionable short-term improvement in those with sciatica but are of no long term benefit. There are also concerns of potential side effects.