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
There is no cure for the alien hand syndrome. However, the symptoms can be reduced and managed to some degree by keeping the alien hand occupied and involved in a task, for example by giving it an object to hold in its grasp. Specific learned tasks can restore voluntary control of the hand to a significant degree. One patient with the "frontal" form of alien hand who would reach out to grasp onto different objects (e.g., door handles) as he was walking was given a cane to hold in the alien hand while walking, even though he really did not need a cane for its usual purpose of assisting with balance and facilitating ambulation. With the cane firmly in the grasp of the alien hand, it would generally not release the grasp and drop the cane in order to reach out to grasp onto a different object. Other techniques proven to be effective includes; wedging the hand between the legs or slapping it; warm water application and visual or tactile contact. Additionally, Wu et al. found that an irritating alarm activated by biofeedback reduced the time the alien hand held an object.
In the presence of unilateral damage to a single cerebral hemisphere, there is generally a gradual reduction in the frequency of alien behaviors observed over time and a gradual restoration of voluntary control over the affected hand. Actually, when AHS originates from focal injury of acute onset, recovery usually occurs within a year. One theory is that neuroplasticity in the bihemispheric and subcortical brain systems involved in voluntary movement production can serve to re-establish the connection between the executive production process and the internal self-generation and registration process. Exactly how this may occur is not well understood, but a process of gradual recovery from alien hand syndrome when the damage is confined to a single cerebral hemisphere has been reported. In some instances, patients may resort to constraining the wayward, undesirable and sometimes embarrassing actions of the impaired hand by voluntarily grasping onto the forearm of the impaired hand using the intact hand. This observed behavior has been termed "self-restriction" or "self-grasping".
In another approach, the patient is trained to perform a specific task, such as moving the alien hand to contact a specific object or a highly salient environmental target, which is a movement that the patient can learn to generate voluntarily through focused training in order to effectively override the alien behavior. It is possible that some of this training produces a re-organization of premotor systems within the damaged hemisphere, or, alternatively, that ipsilateral control of the limb from the intact hemisphere may be expanded.
Another method involves simultaneously "muffling" the action of the alien hand and limiting the sensory feedback coming back to the hand from environmental contact by placing it in a restrictive "cloak" such as a specialized soft foam hand orthosis or, alternatively, an everyday oven mitt. Other patients have reported using an orthotic device to restrict perseverative grasping or restraining the alien hand by securing it to the bed pole. Of course, this can limit the degree to which the hand can participate in addressing functional goals for the patient and may be considered to be an unjustifiable restraint.
Theoretically, this approach could slow down the process through which voluntary control of the hand is restored if the neuroplasticity that underlies recovery involves the recurrent exercise of voluntary will to control the actions of the hand in a functional context and the associated experiential reinforcement through successful willful suppression of the alien behavior.
Non-selective beta-blockers are the most effective in reducing the frequency and severity of PSH episodes. They help decrease the effect of circulating catecholamines and lower metabolic rates, which are high in patients during PSH episodes. Beta-blockers also help in reducing fever, diaphoresis, and in some cases dystonia. Propanolol is a common beta-blocker administered due to the fact that it penetrates the blood-brain barrier relatively well. Typically it is administered in doses of twenty milligrams to sixty milligrams every four to six hours in the treatment of PSH.
The two most common medications used in the treatment of paroxysmal sympathetic hyperactivity are morphine sulfate and beta-blockers. Morphine is useful in helping halt episodes that have started to occur. Beta-blockers are helpful in preventing the occurrence of 'sympathetic storms'. Other drugs that have been used and have in some cases been helpful are dopamine agonists, other various opiates, benzodiazepines, clonidine, and baclofen. Chlorpromazine and haloperidol, both dopamine antagonists, in some cases have worsened PSH symptoms. These drugs are in use currently for treatment; exact pathways are not known and wide-range helpfulness is speculative.
No high quality evidence has shown any drug very useful as of 2013. Rufinamide, lamotrigine, topiramate and felbamate may be useful.
LGS seizures are often treatment resistant, but this does not mean that treatment is futile. Options include anticonvulsants, anesthetics, steroids such as prednisone, immunoglobulins, and various other pharmacological agents that have been reported to work in individual patients.
There are various levels of consciousness. Wakefulness and general anesthesia are two extremes of the spectrum. Conscious sedation and monitored anesthesia care (MAC) refer to an awareness somewhere in the middle of the spectrum depending on the degree to which a patient is sedated. Awareness/wakefulness does not necessarily imply pain or discomfort. The aim of conscious sedation or monitored anesthetic care is to provide a safe and comfortable anesthetic while maintaining the patient's ability to follow commands.
Under certain circumstances, a general anesthetic, whereby the patient is completely unconscious, may be unnecessary and/or undesirable. For instance, with a cesarean delivery, the goal is to provide comfort with neuraxial anesthetic yet maintain consciousness so that the mother can participate in the birth of her child. Other circumstances may include, but are not limited to, procedures that are minimally invasive or purely diagnostic (and thus not uncomfortable). Sometimes, the patient's health may not tolerate the stress of general anesthesia. The decision to provide monitored anesthesia care versus general anesthesia can be complex involving careful consideration of individual circumstances and after discussion with the patient as to their preferences.
Patients who undergo conscious sedation or monitored anesthesia care are never meant to be without recall. Whether or not a patient remembers the procedure depends on the type of medications used, the dosages used, patient physiology, and other factors. Many patients undergoing monitored anesthesia do not remember the experience.
Individual therapy may be best suited to treat the individual's delusions. Persistence is needed in establishing a therapeutic empathy without validating the patient’s delusional system or overtly confronting the system. Cognitive techniques that include reality testing and reframing can be used. Antipsychotics and other therapeutic drugs have been used with relative success.
Human errors include repeated attempts at intubation during which the short-acting anesthesic may wear off but the paralysing drug has not, oesophageal intubation, inadequate drug dose, drug given by the wrong route or wrong drug given, drugs given in the wrong sequence, inadequate monitoring, patient abandonment, disconnections and kinks in tubes from the ventilator, and failure to refill the anesthetic machine's vaporizers with volatile anesthetic. Other causes of awareness include unfamiliarity with techniques used, e.g. intravenous anesthetic regimes, or inexperience. Most cases of awareness are caused by inexperience and poor anesthetic technique, which can be any of the above, but also includes techniques that could be described as outside the boundaries of "normal" practice. The American Society of Anesthesiologists recently released a Practice Advisory outlining the steps that anesthesia professionals and hospitals should take to minimize these risks. Other societies have released their own versions of these guidelines, including the Australian and New Zealand College of Anaesthetists.
Machine malfunction or misuse may result in an inadequate delivery of anesthetic. Many Boyle's machines used in many hospitals have the oxygen regulator serving as a slave to the pressure in the nitrous oxide regulator, to enable the nitrous oxide cut-off safety feature. If nitrous oxide delivery suffers due to a leak in its regulator or tubing, an 'inadequate' mixture can be delivered to the patient, causing awareness. Many World War II vintage Boyle 'F' models are still functional and used in UK hospitals. Their emergency oxygen flush valves have a tendency to release oxygen into the breathing system, which when added to the mixture set by the anesthesiologist, can lead to awareness. This may also be caused by an empty vaporizer (or nitrous oxide cylinder) or a malfunctioning intravenous pump or disconnection of its delivery tubing. Patient abandonment, when the anesthesiologist leaves, causes some cases of awareness and death.
To reduce the likelihood of awareness, anesthetists must be adequately trained and supervised while still in training. Equipment that monitors depth of anesthesia, such as bispectral index monitoring, should not be used in isolation.
A widely accepted treatment for the syndrome of subjective doubles has not been developed. Treatment methods for this disease sometimes include the prescription of antipsychotic drugs, however, the type of drug prescribed depends on the presence of other mental disorders. Antipsychotic drugs (also known as neuroleptics) such as risperidone, pimozide, or haloperidol may be prescribed to treat the underlying psychiatric illness.
In addition to drug therapy, interpersonal counseling has also been suggested as a method to ease relations between the patient and his/her suspected doubles. However, the relationship between the patient and his/her double is not always negative.
There is no method available to completely cure anomic aphasia. However, there are treatments to help improve word-finding skills.
Although a person with anomia may find it difficult to recall many types of words such as common nouns, proper nouns, verbs, etc., many studies have shown that treatment for object words, or nouns, has shown promise in rehabilitation research. The treatment includes visual aids, such as pictures, and the patient is asked to identify the object or activity. However, if that is not possible, then the patient is shown the same picture surrounded by words associated with the object or activity. Throughout the process, positive encouragement is provided. The treatment shows an increase in word-finding during treatment; however, word identifying decreased two weeks after the rehabilitation period. Therefore, it shows that rehabilitation effort needs to be continuous for word-finding abilities to improve from the baseline. The studies show that verbs are harder to recall or repeat, even with rehabilitation.
Other methods in treating anomic aphasia include Circumlocution Induced Naming therapy (CIN), wherein the patient uses circumlocution to assist with his or her naming rather than just being told to name the item pictured after given some sort of cue. Results suggest that the patient does better in properly naming objects when undergoing this therapy because CIN strengthens the weakened link between semantics and phonology for patients with anomia, since they often know what an object is used for but cannot verbally name it.
Anomia is often burdensome on the families and friends of those suffering from it. One way to overcome this burden is computer-based treatment models, effective especially when used with clinical therapy. Leemann et al. provided anomic patients with computerized-assisted therapy (CAT) sessions, along with traditional therapy sessions using treatment lists of words. Some of the patients received a drug known to help relieve symptoms of anomia (levodopa) while others received a placebo. The researchers found that the drug had no significant effects on improvement with the treatment lists, but almost all of the patients improved after the CAT sessions. They concluded that this form of computerized treatment is effective in increasing naming abilities in anomic patients.
Additionally, one study researched the effects of using "excitatory (anodal) transcranial direct current stimulation" over the right temporo-parietal cortex, a brain area that seems to correlate to language. The electrical stimulation seemed to enhance language training outcome in patients with chronic aphasia.
Treating auditory verbal agnosia with intravenous immunoglobulin (IVIG) is controversial because of its inconsistency as a treatment method. Although IVIG is normally used to treat immune diseases, some individuals with auditory verbal agnosia have responded positively to the use of IVIG. Additionally, patients are more likely to relapse when treated with IVIG than other pharmacological treatments. IVIG is, thus, a controversial treatment as its efficacy in treating auditory verbal agnosia is dependent upon each individual and varies from case to case.
Though there have been ample attempts to rehabilitate patients with pure alexia, few have proven to be effective on a large scale. Most rehabilitation practices have been specialized to a single patient or small patient group. At the simplest level, patients seeking rehabilitation are asked to practice reading words aloud repeatedly. This is meant to stimulate the damaged system of the brain. This is known as multiple oral re-reading (MOR) treatment. This is a text-based approach that is implemented in order to prevent patients from LBL reading. MOR works by reading aloud the same text repeatedly until certain criteria are reached. The most important criteria for a pure alexic patient is reading at an improved rate. The treatment aims to shift patients away from the LBL reading strategy by strengthening links between visual input and the associated orthographic representations. This repetition supports the idea of using top-down processing initially minimize the effects peripheral processing which were demonstrated in the study above. From here, the goal is to increasing bottom-up processing. This will hopefully aid in word recognition and promote interactive processing of all available information to support reading. 'The supported reading stimulation from MOR has a rehabilitative effect so that reading rate and accuracy are better for untrained text, and word-form recognition improves as evidenced by a reduced word-length effect.' These tactics have seen quite good success.
Another tactic that has been employed is the use of cross modal therapy. In this therapy, patients are asked to trace the words in which they are trying to read aloud. There has been success using cross modal therapy such as kinaesthetic or motor-cross cuing therapy, but tends to be a more feasible approach for those on the slower reading end of the spectrum.
Alien hand syndrome (AHS) is a condition in which a person experiences their limbs acting seemingly on their own, without control over the actions. The term is used for a variety of clinical conditions and most commonly affects the left hand. There are many similar names used to describe the various forms of the condition but they are often used inappropriately. The afflicted person may sometimes reach for objects and manipulate them without wanting to do so, even to the point of having to use the controllable hand to restrain the alien hand. While under normal circumstances, thought, as intent, and action can be assumed to be deeply mutually entangled, the occurrence of alien hand syndrome can be usefully conceptualized as a phenomenon reflecting a functional "disentanglement" between thought and action.
Alien hand syndrome is best documented in cases where a person has had the two hemispheres of their brain surgically separated, a procedure sometimes used to relieve the symptoms of extreme cases of epilepsy and epileptic psychosis, e.g., temporal lobe epilepsy. It also occurs in some cases after brain surgery, stroke, infection, tumor, aneurysm, migraine and specific degenerative brain conditions such as Alzheimer's disease and Creutzfeldt–Jakob disease. Other areas of the brain that are associated with alien hand syndrome are the frontal, occipital, and parietal lobes.
The article "Cotard's syndrome: A Review" (2010) reports successful pharmacological treatments (mono-therapeutic and multi-therapeutic) using antidepressant, antipsychotic, and mood stabilizing drugs; likewise, with the depressed patient, electroconvulsive therapy (ECT) is more effective than pharmacotherapy. Cotard syndrome resulting from an adverse drug reaction to valacyclovir is attributed to elevated serum concentration of one of valacyclovir's metabolites, 9-carboxymethoxymethylguanine (CMMG). Successful treatment warrants cessation of the drug, valacyclovir. Hemodialysis was associated with timely clearance of CMMG and resolution of symptoms.
Recovery from this syndrome is situational, as some drug therapies have been effective in some individuals but not others. Patients may live in a variety of settings, including psychiatric hospitals, depending on the success of treatment. With successful treatment, an individual may live at home. In many of the reported cases, remission of symptoms occurred during the follow-up period.
This disorder can be dangerous to the patient and others, as a patient may interrogate or attack a person they believe to be a double. Inappropriate behavior such as stalking and physical or psychological abuse has been documented in some case studies. Consequently, many individuals suffering from this disorder are arrested for the resulting misconduct (see the case of Mr. B in #Presentation).
Approaches used to treat those who suffer from anterograde amnesia often use interventions which focus on compensatory techniques, such as beepers, written notes, diaries or through intensive training programs involving the active participation of the individual concerned, along with their supporting network of family and friends.
In this perspective, environmental adaptation techniques are used, such as the compensatory technique education to training (exercise), organizational strategies, visual imagery and verbal labeling. In addition, other techniques are also used in rehabilitation, such as implicit tasks, speech and mnemotechnic methods.
So far, it has been proven that education techniques of compensatory strategies for memory disorders are effective in individuals with minor traumatic brain injuries. In moderately or severely injured individuals, effective interventions are those appealing to external aids, such as reminders in order to facilitate particular knowledge or skill acquisition. Reality orientation techniques are also considered; Their purpose is to enhance orientation using stimulation and repetition of the basic orientation information. These techniques are regularly applied in populations of patients primarily presenting with dementia and head-injured patients.
In incidents where tumors and their pressure effects are the cause of pure word deafness, removal of the tumor has been shown to allow for the return of most auditory verbal comprehension.
With due regard for the cause of the coma, and the rapidity of its onset, testing for the purpose of diagnosing death on brainstem death grounds may be delayed beyond the stage where brainstem reflexes may be absent only temporarily – because the cerebral blood flow is inadequate to support synaptic function although there is still sufficient blood flow to keep brain cells alive and capable of recovery. There has recently been renewed interest in the possibility of neuronal protection during this phase by use of moderate hypothermia and by correction of the neuroendocrine abnormalities commonly seen in this early stage.
Published studies of patients meeting the criteria for brainstem death or whole brain death – the American standard which includes brainstem death diagnosed by similar means – record that even if ventilation is continued after diagnosis, the heart stops beating within only a few hours or days. However, there have been some very long-term survivals and it is noteworthy that expert management can maintain the bodily functions of pregnant brain dead women for long enough to bring them to term.
The management of patients pronounced dead on meeting the brainstem death criteria depends upon the reason for diagnosing death on that basis. If the intent is to take organs from the body for transplantation, the ventilator is reconnected and life-support measures are continued, perhaps intensified, with the addition of procedures designed to protect the wanted organs until they can be removed. Otherwise, the ventilator is left disconnected on confirmation of the lack of respiratory centre response.
Brainstem death is a clinical syndrome defined by the absence of reflexes with pathways through the brainstem—the “stalk” of the brain, which connects the spinal cord to the mid-brain, cerebellum and cerebral hemispheres—in a deeply comatose, ventilator-dependent patient.
Identification of this state carries a very grave prognosis for survival; cessation of heartbeat often occurs within a few days although it may continue for weeks or even months if intensive support is maintained.
In the United Kingdom, the formal diagnosis of brainstem death by the procedure laid down in the official Code of Practice permits the diagnosis and certification of death on the premise that a person is dead when consciousness and the ability to breathe are permanently lost, regardless of continuing life in the body and parts of the brain, and that death of the brainstem alone is sufficient to produce this state.
This concept of brainstem death is also accepted as grounds for pronouncing death for legal purposes in India and Trinidad & Tobago. Elsewhere in the world the concept upon which the certification of death on neurological grounds is based is that of permanent cessation of all function in all parts of the brain—whole brain death—with which the reductionist United Kingdom concept should not be confused. The United States' President's Council on Bioethics made it clear, in its White Paper of December 2008, that the United Kingdom concept and clinical criteria are not considered sufficient for the diagnosis of death in the United States of America.
Treatment for aphasias is generally individualized, focusing on specific language and communication improvements, and regular exercise with communication tasks. Regular therapy for conduction aphasics has been shown to result in steady improvement on the Western Aphasia Battery. However, conduction aphasia is a mild aphasia, and conduction aphasics score highly on the WAB at baseline.
If the symptoms of alcohol dementia are caught early enough, the effects may be reversed. The person must stop drinking and start on a healthy diet, replacing the lost vitamins, including, but not limited to, thiamine. Recovery is more easily achievable for women than men, but in all cases it is necessary that they have the support of family and friends and abstain from alcohol.
The general purpose of the following treatment methods is to divert the flow of CSF from the blocked aqueduct, which is causing the buildup of CSF, and allow the flow to continue. Another goal of these treatments is to reduce the stress within the ventricles. Studies have not shown that either of the following treatments results in a higher IQ of the patient, and there is not statistical difference in a patient's quality of life based on treatment method. The following treatment methods are not used for aqueductal stenosis caused by tumor compression; if the obstruction is a direct result of tumor compression, CSF flow may be normalized by the surgical removal of the tumor.
Disconnection syndrome is a general term for a number of neurological symptoms caused by damage to the white matter axons of communication pathways—via lesions to association fibers or commissural fibers—in the cerebrum, independent of any lesions to the cortex. The behavioral effects of such disconnections are relatively predictable in adults. Disconnection syndromes usually reflect circumstances where regions A and B still have their functional specializations except in domains that depend on the interconnections between the two regions.
Callosal syndrome, or split-brain, is an example of a disconnection syndrome from damage to the corpus callosum between the two hemispheres of the brain. Disconnection syndrome can also lead to aphasia, left-sided apraxia, and tactile aphasia, among other symptoms. Other types of disconnection syndrome include conduction aphasia (lesion of the association tract connecting Broca’s area and Wernicke’s), agnosia, apraxia, pure alexia, etc.
An endoscopic third ventriculostomy (ETV) is a procedure where an incision is made in the bottom of the third ventricle to make a drainage point for CSF to flow out of. The procedure is minimally invasive and is performed endoscopically. The goal in the surgery is to create a path for communication between the third ventricle and the subarachnoid space outside the brain for reabsorption of CSF. ETV has a higher failure rate than shunting during the first 3 postoperative months, but after this time the risk of failure progressively drops to become half as high as the failure risk for shunting.
This treatment does not place a foreign body into the patient so there is a much lower risk of infection as compared to a shunt procedure. Along with not implanting a device, this procedure avoids mechanical issues like disconnection, over or underdrainage, and valve dysfunction. The surgery begins by entering the right or left lateral ventricle endoscopically through a burr hole. The third ventricle is identified and entered as well, and an incision is made in the floor of the ventricle and enlarged as necessary with tools such as forceps or Fogarty catheters. If a membrane prevents CSF flow between the ventricle and the subarachnoid space, then an incision is made in the membrane as well. Ideally this procedure can be performed near the midline of the brain with minimal side-to-side motions of the endoscope so as to not tear tissues and cause further complications.
Research has found that this procedure has a 75% success rate, that 72% of ETV surgeries are still correctly functioning after 15 years, and that patients have shorter hospital stays recovering as compared to shunting. If the procedure does not successfully cure the aqueductal stenosis, a second surgery can be performed to enlarge the incision or implant a shunt. Problems that can lead to these failures and require additional surgery include the stoma becoming closed or a new membrane forming across the stoma over time. Currently there is no universal decision about whether this should be performed in children, as infants have a higher tendency to have a membrane form over the incision which means that an additional surgery would have to be performed.
Diaschisis (from Greek διάσχισις meaning "shocked throughout") is a sudden loss (or change) of function in a portion of the brain connected to a distant, but damaged, brain area. The site of the originally damaged area and of the diaschisis are connected to each other by neurons. The loss of the damaged structure disrupts the function of the remaining intact systems and causes a physiological imbalance. The injury is produced by an acute focal disturbance in an area of the brain, from traumatic brain injury or stroke, for example. Some function may be restored with gradual readjustment of the intact but suppressed areas through intervention and the brain's natural neuroplasticity.
The term "diaschisis" was coined by Constantin von Monakow in 1914. Currently the term "diaschisis" is used to describe a depression of regional neuronal metabolism and cerebral blood flow caused by in an anatomically separate but functionally related neuronal region.
Von Monakow's concept of neurophysical changes in distant brain tissue to the focal lesion led to a widespread clinical interest. Doctors were interested in how diaschisis could describe the signs and symptoms of brain lesions that could not be explained.
The areas of the brain are connected by vast organized neuronal pathways that allow one area of the brain to influence other areas more distal to it. Understanding these dense pathways helps to link a lesion causing brain damage in one area of the brain to degeneration in a more distal brain area. A focal lesion causes damage that also disturbs the structural and functional connectivity to the brain areas distal to the lesion.
The primary mechanism of diaschisis is functional deafferentation, which is the loss of the input of information from the part of the brain that is now damaged. The decrease in information and neural firing to the distal brain area causes those synaptic connections to weaken and initiates a change in the structural and functional connectivity around that area. This leads to diaschisis. Diaschisis is also influenced by many other factors, including stoke, brain swelling, and neuroanatomical disconnection. The severity of these factors is manifested in altered neuronal excitability, hypo-metabolism, and hypo perfusion.
There are two types of diaschisis. The first is focal diaschisis, which refers to the remote neurophysiological changes that are caused by a focal lesion based on von Monakow's definition. The second type of diaschisis is non-focal diaschisis and it focuses on the changes in the strength and direction of neural pathways and connectivity between brain areas. This type of diaschisis has only been a topic in recent study as a result of the advancement of brain imaging tools and technology. These new tools allow for better understanding of the organization of the brain connectivity and further investigation into new types of diaschisis, like non-focal or connectional diascisis. This new type of diaschisis relates much more closely to clinical findings.