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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)
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A number of factors can decrease the risk of dementia. A group of efforts is believed to be able to prevent a third of cases and include early education, treating high blood pressure, preventing obesity, preventing hearing loss, treating depression, being active, preventing diabetes, not smoking, and preventing social isolation.
Among otherwise healthy older people, computerized cognitive training may improve memory. However it is not known if it prevents dementia. Short term exercise has limited evidence. In those with normal mental function evidence for medications is poor. The same applies to supplements.
Because the exact cause of CBD is unknown, there exists no formal treatment for the disease. Instead, treatments focus on minimizing the appearance or effect of the symptoms resulting from CBD. The most easily treatable symptom of CBD is parkinsonism, and the most common form of treatment for this symptom is the application of dopaminergic drugs. However, in general only moderate improvement is seen and the relief from the symptom is not long-lasting. In addition, palliative therapies, including the implementation of wheelchairs, speech therapy, and feeding techniques, are often used to alleviate many of the symptoms that show no improvement with drug administration.
No medications have been shown to prevent or cure dementia. Medications may be used to treat the behavioural and cognitive symptoms but have no effect on the underlying disease process.
Acetylcholinesterase inhibitors, such as donepezil, may be useful for Alzheimer disease and dementia in Parkinson's, DLB, or vascular dementia. The quality of the evidence however is poor and the benefit is small. No difference has been shown between the agents in this family. In a minority of people side effects include a slow heart rate and fainting.
As assessment for an underlying cause of the behavior is a needed before prescribing antipsychotic medication for symptoms of dementia. Antipsychotic drugs should be used to treat dementia only if non-drug therapies have not worked, and the person's actions threaten themselves or others. Aggressive behavior changes are sometimes the result of other solvable problems, that could make treatment with antipsychotics unnecessary. Because people with dementia can be aggressive, resistant to their treatment, and otherwise disruptive, sometimes antipsychotic drugs are considered as a therapy in response. These drugs have risky adverse effects, including increasing the patient's chance of stroke and death. Generally, stopping antipsychotics for people with dementia does not cause problems, even in those who have been on them a long time.
N-methyl-D-aspartate (NMDA) receptor blockers such as memantine may be of benefit but the evidence is less conclusive than for AChEIs. Due to their differing mechanisms of action memantine and acetylcholinesterase inhibitors can be used in combination however the benefit is slight.
While depression is frequently associated with dementia, selective serotonin reuptake inhibitors (SSRIs) do not appear to affect outcomes.
The use of medications to alleviate sleep disturbances that people with dementia often experience has not been well researched, even for medications that are commonly prescribed. In 2012 the American Geriatrics Society recommended that benzodiazepines such as diazepam, and non-benzodiazepine hypnotics, be avoided for people with dementia due to the risks of increased cognitive impairment and falls. Additionally, there is little evidence for the effectiveness of benzodiazepines in this population. There is no clear evidence that melatonin or ramelteon improves sleep for people with dementia due to Alzheimer's disease. There is limited evidence that a low dose of trazodone may improve sleep, however more research is needed.
There is no solid evidence that folate or vitamin B12 improves outcomes in those with cognitive problems. Statins also have no benefit in dementia. Medications for other health conditions may need to be managed differently for a person who also has a diagnosis of dementia. The MATCH-D criteria can help identify ways that a diagnosis of dementia changes medication management for other health conditions. It is unclear if there is a link between blood pressure medication and dementia. There is a possibility that people may experience an increase in cardiovascular-related events if these medications are withdrawn.
Currently, there is no cure for FTD. Treatments are available to manage the behavioral symptoms. Disinhibition and compulsive behaviors can be controlled by selective serotonin reuptake inhibitors (SSRIs). Although Alzheimer's and FTD share certain symptoms, they cannot be treated with the same pharmacological agents because the cholinergic systems are not affected in FTD.
Because FTD often occurs in younger people (i.e. in their 40's or 50's), it can severely affect families. Patients often still have children living in the home. Financially, it can be devastating as the disease strikes at the time of life that often includes the top wage-earning years.
Personality changes in individuals with FTD are involuntary. Managing the disease is unique to each individual, as different patients with FTD will display different symptoms, sometimes of rebellious nature.
Clinical presentation of CBD usually does not occur until age 60, with the earliest recorded diagnosis and subsequent postmortem verification being age 28. Although men and women present with the disease, some analysis has shown a predominant appearance of CBD in women. Current calculations suggest that the prevalence of CBD is approximately 4.9 to 7.3 per 100,000 people. The prognosis for an individual diagnosed with CBD is death within approximately eight years, although some patients have been diagnosed over 17 years ago (2017) and are still in relatively good standing, but with serious debilitation such as dysphagia, and overall limb rigidity. The partial (or total) use of a feeding tube may be necessary and will help prevent aspiration pneumonia, primary cause of death in CBD. Incontinence is common, as patients often can't express their need to go, due to eventual loss of speech. Therefore, proper hygiene is mandatory to prevent urinary tract infections.
Symptoms of frontotemporal dementia progress at a rapid, steady rate. Patients suffering from the disease can survive between 2–15 years. Eventually patients will need 24-hour care for daily function.
CSF leaks are a known cause of reversible frontotemporal dementia.
Riluzole has been found to modestly prolong survival by approximately two to three months. It may have a greater survival benefit for those with a bulbar onset. It is approved by the US Food and Drug Administration (FDA) and recommended by the National Institute for Health and Care Excellence (NICE) (England and Wales). Riluzole does not reverse damage already done to motor neurons but affects neurons by reducing their activity through blocking Na+ entrance into the neurons and thus blocking the release of the chemicals that causes the activity of the motor neurons. The reduction in activity prevents the ruining of the neuronal muscle and so the drug can act as a protective chemical. Studies have shown that the function of this drug is dependent on the amount taken at a given time. The higher the concentration, the better the drug will protect the neurons from ruin. The recommended dosage of Riluzole is 50 mg, twice a day for people with known ALS for more than 5 years.
There are a number of side effects caused by the drug including the feeling of weakness in muscles but this is normal due to the function of the drug. Studies have shown that people on the drug are not likely to stop responding to it or develop symptoms that might cause the activity of neurons to rise again, making Riluzole an effective drug for prolonging survival.
In 2015, edaravone was approved in Japan for treatment of ALS after studying how and whether it works on 137 people with ALS and has obtained orphan drug status in the EU and USA. On May 5, 2017, the FDA approved edaravone to extend the survival period of people with ALS. It costs about 145,000 USD per year in the US and 35,000 USD per year in Japan.
Other medications may be used to help reduce fatigue, ease muscle cramps, control spasticity, and reduce excess saliva and phlegm. Drugs also are available to help people with pain, such as non-steroidal and anti-inflammatory drugs and opioids, depression, sleep disturbances, dysphagia, and constipation. Baclofen and diazepam are often prescribed to control the spasticity caused by ALS, and trihexyphenidyl, amitriptyline or most commonly glycopyrrolate may be prescribed when people with ALS begin having trouble swallowing their saliva. There is no evidence that medications are effective at reducing muscle cramps experienced by people with ALS.
Management of ALS attempts to relieve symptoms and extend life expectancy. This supportive care is best provided by multidisciplinary teams of healthcare professionals working with the person and their caregivers to keep them as mobile and comfortable as possible.
Frontotemporal lobar degeneration (FTLD) is a pathological process that occurs in frontotemporal dementia. It is characterized by atrophy in the frontal lobe and temporal lobe of the brain, with sparing of the parietal and occipital lobes.
Common proteinopathies that are found in FTLD include the accumulation of Tau proteins and TARDBPs. Mutations in the C9orf72 gene have been established as a major genetic contribution of FTLD, although defects in the GRN and MAPT genes are also associated with it.
Neurodegeneration is the progressive loss of structure or function of neurons, including death of neurons. Many neurodegenerative diseases – including amyotrophic lateral sclerosis, Parkinson's, Alzheimer's, and Huntington's – occur as a result of neurodegenerative processes. Such diseases are incurable, resulting in progressive degeneration and/or death of neuron cells. As research progresses, many similarities appear that relate these diseases to one another on a sub-cellular level. Discovering these similarities offers hope for therapeutic advances that could ameliorate many diseases simultaneously. There are many parallels between different neurodegenerative disorders including atypical protein assemblies as well as induced cell death. Neurodegeneration can be found in many different levels of neuronal circuitry ranging from molecular to systemic.
The process of neurodegeneration is not well understood, so the diseases that stem from it have, as yet, no cures. In the search for effective treatments (as opposed to palliative care), investigators employ animal models of disease to test potential therapeutic agents. Model organisms provide an inexpensive and relatively quick means to perform two main functions: target identification and target validation. Together, these help show the value of any specific therapeutic strategies and drugs when attempting to ameliorate disease severity. An example is the drug Dimebon (Medivation). This drug is in phase III clinical trials for use in Alzheimer's disease, and also recently finished phase II clinical trials for use in Huntington's disease. In March 2010, the results of a clinical trial phase III were released; the investigational Alzheimer's disease drug Dimebon failed in the pivotal CONNECTION trial of patients with mild-to-moderate disease. With CONCERT, the remaining Pfizer and Medivation Phase III trial for Dimebon (latrepirdine) in Alzheimer's disease failed in 2012, effectively ending the development in this indication.
In another experiment using a rat model of Alzheimer's disease, it was demonstrated that systemic administration of hypothalamic proline-rich peptide (PRP)-1 offers neuroprotective effects and can prevent neurodegeneration in hippocampus amyloid-beta 25–35. This suggests that there could be therapeutic value to PRP-1.
Protein degradation offers therapeutic options both in preventing the synthesis and degradation of irregular proteins. There is also interest in upregulating autophagy to help clear protein aggregates implicated in neurodegeneration. Both of these options involve very complex pathways that we are only beginning to understand.
The goal of immunotherapy is to enhance aspects of the immune system. Both active and passive vaccinations have been proposed for Alzheimer's disease and other conditions, however more research must be done to prove safety and efficacy in humans.
Lytico-bodig disease, sometimes spelled Lytigo-bodig, is the name of a disease in the language of Chamorro. It is referred to by neuroscientists as amyotrophic lateral sclerosis-parkinsonism-dementia (ALS-PDC), a term coined by Asao Hirano and colleagues in 1961. It is a neurodegenerative disease of uncertain etiology that exists in the United States territory of Guam.
The disease resembles Amyotrophic Lateral Sclerosis (ALS), Parkinson's disease, and Alzheimer's. First reports of the disease surfaced in three death certificates on Guam in 1904. These death certificates made some mention of paralysis. The frequency of cases grew amongst the Chamorro people on Guam until it was the leading cause of adult death between 1945 and 1956. The incidence rate was 200 per 100,000 per year and it was 100 times more prevalent than in the rest of the world.
Neurologist Oliver Sacks detailed this disease in his book "The Island of the Colorblind"
. Sacks and Paul Alan Cox subsequently wrote that a local species of flying fox, which is now extinct due to overhunting, had been feeding on cycads and concentrating β-methylamino--alanine (BMAA), a known neurotoxin, in its body fat. The hypothesis suggests that consumption of the fruit bat by the Chamorro exposed them to BMAA, contributing to or causing their condition. Decline in consumption of the bats has been linked to a decline in the incidence of the disease.
There are 3 main histological subtypes found at post-mortem:
- FTLD-tau is characterised by tau positive inclusions often referred to as Pick-bodies. Examples of FTLD-tau include; Pick's disease, corticobasal degeneration, progressive supranuclear palsy.
- FTLD-TDP (or FTLD-U ) is characterised by ubiquitin and TDP-43 positive, tau negative, FUS negative inclusions. The pathological histology of this subtype is so diverse it is subdivided into four subtypes based on the detailed histological findings:
Two physicians independently categorized the various forms of TDP-43 associated disorders. Both classifications were considered equally valid by the medical community, but the physicians in question have jointly proposed a compromise classification to avoid confusion.
- FTLD-FUS; which is characterised by FUS positive cytoplasmic inclusions, intra nuclear inclusions, and neuritic threads. All of which are present in the cortex, medulla, hippocampus, and motor cells of the spinal cord and XIIth cranial nerve.
Dementia lacking distinctive histology (DLDH) is a rare and controversial entity. New analyses have allowed many cases previously described as DLDH to be reclassified into one of the positively defined subgroups.
Some hypotheses as to the cause of the disease include genetics, cycad seeds, and ingested beta-Methylamino-L-alanine (BMAA) from the consumption of fruit bats.
A motor neuron disease (MND) is any of several neurological disorders that selectively affect motor neurons, the cells that control voluntary muscles of the body. They include amyotrophic lateral sclerosis (ALS), hereditary spastic paraplegia (HSP), primary lateral sclerosis (PLS), progressive muscular atrophy (PMA), progressive bulbar palsy (PBP) and pseudobulbar palsy. Spinal muscular atrophies (SMA) are sometimes included in the group by some neurologists but it is different disease with clear genetic cause. They are neurodegenerative in nature and cause increasing disability and eventually, death.
Treatment for individuals with PLS is symptomatic. Baclofen and tizanidine may reduce spasticity. Quinine or phenytoin may decrease cramps. Some patients who do not receive adequate relief from oral treatment may consider intrathecal baclofen (i.e., infusion of medication directly into the cerebrospinal fluid via a surgically placed continuous infusion pump). However, patients are carefully selected for this type of procedure to ensure that they will likely benefit from this invasive procedure.
Physical therapy often helps prevent joint immobility. Speech therapy may be useful for those with involvement of the facial muscles. Physiotherapy treatment focuses on reducing muscle tone, maintaining or improving range of motion, increasing strength and coordination, and improving functional mobility. In PLS, stretching is thought to improve flexibility and can also reduce muscle spasticity and cramps.
Patients with PLS may find it beneficial to have an evaluation, as well as follow-up visits at multidisciplinary clinics, similar to those available for people with ALS. These multidisciplinary clinics may provide patients with the necessary treatment that they require by having an occupational therapist, physical therapist, speech language pathologist, dietician and nutritionist, all in one site.
The importance of correctly recognizing progressive muscular atrophy as opposed to ALS is important for several reasons.
- 1) the prognosis is a little better. A recent study found the 5-year survival rate in PMA to be 33% (vs 20% in ALS) and the 10-year survival rate to be 12% (vs 6% in ALS).
- 2) Patients with PMA do not suffer from the cognitive change identified in certain groups of patients with MND.
- 3) Because PMA patients do not have UMN signs, they usually do not meet the "World Federation of Neurology El Escorial Research Criteria" for “Definite” or “Probable” ALS and so are ineligible to participate in the majority of clinical research trials such as drugs trials or brain scans.
- 4) Because of its rarity (even compared to ALS) and confusion about the condition, some insurance policies or local healthcare policies may not recognize PMA as being the life-changing illness that it is. In cases where being classified as being PMA rather than ALS is likely to restrict access to services, it may be preferable to be diagnosed as "slowly progressive ALS" or "lower motor neuron predominant" ALS.
An initial diagnosis of PMA could turn out to be slowly progressive ALS many years later, sometimes even decades after the initial diagnosis. The occurrence of upper motor neurone symptoms such as brisk reflexes, spasticity, or a Babinski sign would indicate a progression to ALS; the correct diagnosis is also occasionally made on autopsy.
In the United States, the term is often used to denote ALS, the most common disorder in the group. In the United Kingdom, the term is also spelled "motor neurone disease" (MND) and is sometimes used for the entire group; but mostly it refers to ALS.
While MND refers to a specific subset of similar diseases, there are numerous other diseases of motor neurons that are referred to collectively as "motor neuron disorders", for instance disease belonging to spinal muscular atrophies. However, they are not classified as "motor neuron diseases" by the tenth International Statistical Classification of Diseases and Related Health Problems (ICD-10), which is the definition followed in this article.
Investigators have demonstrated that immobilizing the head during a blast exposure prevented the learning and memory deficits associated with CTE that occurred when the head was not immobilized. This research represents the first case series of postmortem brains from U.S. military personnel who were exposed to a blast and/or a concussive injury.
Because of the concern that boxing may cause DP, there is a movement among medical professionals to ban the sport. Medical professionals have called for such a ban since as early as the 1950s.
In 2005 forensic pathologist Bennet Omalu, along with colleagues in the Department of Pathology at the University of Pittsburgh, published a paper, "Chronic Traumatic Encephalopathy in a National Football League Player", in the journal "Neurosurgery", based on analysis of the brain of deceased former NFL center Mike Webster. This was then followed by a paper on a second case in 2006 describing similar pathology, based on findings in the brain of former NFL player Terry Long.
In 2008, the CSTE at Boston University at the BU School of Medicine started the CSTE brain bank at the Bedford VA Hospital to analyze the effects of CTE and other neurodegenerative diseases on the brain and spinal cord of athletes, military veterans, and civilians To date, the CSTE Brain Bank is the largest CTE tissue repository in the world.
On December 21, 2009, the National Football League Players Association announced that it would collaborate with the CSTE at the Boston University School of Medicine to support the Center's study of repetitive brain trauma in athletes. Additionally, in 2010 the National Football League gave the CSTE a $1 million gift with no strings attached. In 2008, twelve living athletes (active and retired), including hockey players Pat LaFontaine and Noah Welch as well as former NFL star Ted Johnson, committed to donate their brains to CSTE after their deaths. In 2009, NFL Pro Bowlers Matt Birk, Lofa Tatupu, and Sean Morey pledged to donate their brains to the CSTE. In 2010, 20 more NFL players and former players pledged to join the CSTE Brain Donation Registry, including Chicago Bears linebacker Hunter Hillenmeyer, Hall of Famer Mike Haynes, Pro Bowlers Zach Thomas, Kyle Turley, and Conrad Dobler, Super Bowl Champion Don Hasselbeck and former pro players Lew Carpenter, and Todd Hendricks. In 2010, Professional Wrestlers Mick Foley, Booker T and Matt Morgan also agreed to donate their brains upon their deaths. Also in 2010, MLS player Taylor Twellman, who had to retire from the New England Revolution because of post-concussion symptoms, agreed to donate his brain upon his death. As of 2010, the CSTE Brain Donation Registry consists of over 250 current and former athletes. In 2011, former North Queensland Cowboys player Shaun Valentine became the first rugby player to agree to donate his brain upon his death, in response to recent concerns about the effects of concussions on Rugby League players, who do not use helmets. Also in 2011, boxer Micky Ward, whose career inspired the film The Fighter, agreed to donate his brain upon his death.
In related research, the Center for the Study of Retired Athletes, which is part of the Department of Exercise and Sport Science at the University of North Carolina at Chapel Hill, is conducting research funded by National Football League Charities to "study former football players, a population with a high prevalence of exposure to prior Mild Traumatic Brain Injury (MTBI) and sub-concussive impacts, in order to investigate the association between increased football exposure and recurrent MTBI and neurodegenerative disorders such as cognitive impairment and Alzheimer's disease (AD)".
In February 2011, Dave Duerson committed suicide, leaving text messages to loved ones asking that his brain be donated to research for CTE. The family got in touch with representatives of the Boston University center studying the condition, said Robert Stern, the co-director of the research group. Stern said Duerson's was the first time he was aware of that such a request had been left by a suicide potentially linked to CTE. Stern and his colleagues found high levels of the protein tau in Duerson's brain. These elevated levels, which were abnormally clumped and pooled along the brain sulci, are indicative of CTE.
In July 2010, NHL enforcer Bob Probert died of heart failure. Before his death, he asked his wife to donate his brain to CTE research because it was noticed that Probert experienced a mental decline in his 40s. In March 2011, researchers at Boston University concluded that Probert had CTE upon analysis of the brain tissue he donated. He is the second NHL player from the program at the Center for the Study of Traumatic Encephalopathy to be diagnosed with CTE postmortem.
BUSM has also found indications of links between Amyotrophic lateral sclerosis (ALS) and CTE in athletes who have participated in contact sports. Tissue for the study was donated by twelve athletes and their families to the CSTE Brain Bank at the Bedford, Massachusetts VA Medical Center.
In 2013, President Barack Obama announced the creation of the Chronic Effects of Neurotrauma Consortium or CENC, a federally funded research project devised to address the long-term effects of mild traumatic brain injury in military service personnel (SM's) and Veterans. The CENC is a multi-center collaboration linking premiere basic science, translational, and clinical neuroscience researchers from the DoD, VA, academic universities, and private research institutes to effectively address the scientific, diagnostic, and therapeutic ramifications of mild TBI and its long-term effects. Nearly 20% of the more than 2.5 million U.S. Service Members (SMs) deployed since 2003 to Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) have sustained at least one traumatic brain injury (TBI), predominantly mild TBI (mTBI), and almost 8% of all OEF/OIF Veterans demonstrate persistent post-TBI symptoms more than six months post-injury. Unlike those head injuries incurred in most sporting events, recent military head injuries are most often the result of blast wave exposure. After a competitive application process, a consortium led by Virginia Commonwealth University was awarded funding. The project principal investigator for the CENC is David Cifu, Chairman and Herman J. Flax professor of the Department of Physical Medicine and Rehabilitation (PM&R) at Virginia Commonwealth University (VCU) in Richmond, Virginia, with co-principal investigators Ramon Diaz-Arrastia, Professor of Neurology, Uniformed Services University of the Health Sciences, and Rick L. Williams, statistician at RTI International.
Some researchers have argued that prospective longitudinal studies, following subjects over time, are needed to more completely understand the causes and progression of CTE.
As of September 2015, the CSTE had diagnosed CTE in 96% of NFL players analyzed in postmortem brain studies.
PBP is aggressive and relentless, and there were no treatments for the disease as of 2005. However, early detection of PBP is the optimal scenario in which doctors can map out a plan for management of the disease. This typically involves symptomatic treatments that are frequently used in many lower motor disorders.
Patients can often live with PLS for many years and very often outlive their neurological disease and succumb to some unrelated condition. There is currently no effective cure, and the progression of symptoms varies. Some people may retain the ability to walk without assistance, but others eventually require wheelchairs, canes, or other assistive devices.
Currently there is no cure for dysmetria itself as it is actually a symptom of an underlying disorder. However, isoniazid and clonazepam have been used to treat dysmetria. Frenkel exercises treat dysmetria. There have also been numerous reported cases of chiropractic neurology as an effective holistic treatment for dysmetria. Cannabis has been used in trials in the U.K. and displayed some success, though it is not legal to use in some U.S. states.
Progressive Bulbar Palsy is slow in onset, with symptoms starting in most patients around 50–70 years of age. PBP has a life expectancy typically between 6 months and 3 years from onset of first symptoms. It is subtype of the Motor Neurone Diseases (MND) accounting for around 1 in 4 cases. Amyotrophic lateral sclerosis (ALS) is another sub-type. Pure PBP without any EMG or clinical evidence of abnormalities in the legs or arms is possible, albeit extremely rare. Moreover, about twenty-five percent of patients with PBP eventually develop the widespread symptoms common to ALS.
Dextromethorphan hydrobromide is a generic drug that affects the signals in the brain that trigger the cough reflex. It is generally used as a cough suppressant, although it can sometimes be used, medicinally, as a pain reliever, and is also used as a recreational drug. "Dextromethorphan (DM) is a sigma-1 receptor agonist and an uncompetitive NMDA receptor antagonist."
Quinidine sulfate affects the way the heart beats, and is generally used in people with certain heart rhythm disorders. It is also used to treat malaria. Quinidine sulfate, as a metabolic inhibitor, "increases plasma levels of dextromethorphan by competitively inhibiting cytochrome P450 2D6, which catalyzes a major biotransformation pathway for dextromethorphan," enabling therapeutic dextromethorphan concentrations.
Nuedexta is a patented combination of these two generic drugs, and is the first FDA-approved drug for the treatment of PBA, approved on October 29, 2010. In December 2007, clinical study information for Nuedexta was first submitted to ClinicalTrials.gov, (a Web-based resource maintained by the National Library of Medicine (NLM) at the National Institutes of Health (NIH)). Sponsored by Avanir Pharmaceuticals, (with brief title, "Safety and Efficacy of AVP-923 in PBA Patients With ALS or MS"), the study was assigned NCT Number NCT00573443. Final updates and verifications occurred in June 2013 on the ClinicalTrials.gov site.
For this multicenter study, the "Objectives...[were] to evaluate the safety, tolerability, and efficacy of two different doses of AVP-923 [Dextromethorphan/quinidine combination]...when compared to placebo." The conditions and results of that study are as follows:
Other studies have confirmed the results of NCT00573443, but, "The mechanism by which dextromethorphan exerts therapeutic effects in patients with pseudobulbar affect is unknown."