This is a terminal condition and there is currently no specific treatment for the disease.

Treatment varies according to the type and severity of the encephalopathy. Anticonvulsants may be prescribed to reduce or halt any seizures. Changes to diet and nutritional supplements may help some patients. In severe cases, dialysis or organ replacement surgery may be needed.

Sympathomimetic drugs can increase motivation, cognition, motor performance and alertness in patients with encephalopathy caused by brain injury, chronic infections, strokes, brain tumors.

Exotic ungulate encephalopathy is a transmissible spongiform encephalopathy (TSE), or prion disease, identified in infected organs of zoo animals. This subgroup of the TSEs in captive animals was identified in zoo animals in Great Britain including species of greater kudu, nyala, gemsbok, the common eland, Arabian and Scimitar Oryx, an Ankole-Watusi cow, and an American bison. Studies indicate that transmission likely occurred via the consumption of feed supplemented with meat and bone meal, although some animals died after the British ban on ground offal in animal feed. All animals died during the 1990s, with the last death occurring in 1998.

Treatment is mainly for the symptoms that toxic encephalopathy brings upon victims, varying depending on how severe the case is. Diet changes and nutritional supplements may help some patients. To reduce or halt seizures, anticonvulsants may be prescribed. Dialysis or organ replacement surgery may be needed in some severe cases.

Management of affected individuals consists of immediate removal from exposure to the toxic substance(s), treatment of the common clinical manifestation of depression if present, and counselling for the provision of life strategies to help cope with the potentially debilitating condition.

Feline spongiform encephalopathy is a disease that affects the brains of felines. It is caused by proteins called prions.

Treating the underlying cause of the disorder may improve or reverse symptoms. However, in some cases, the encephalopathy may cause permanent structural changes and irreversible damage to the brain. These permanent deficits can be considered a form of stable dementia. Some encephalopathies can be fatal.

There continues to be a very practical problem with diagnosis of prion diseases, including BSE and CJD. They have an incubation period of months to decades during which there are no symptoms, even though the pathway of converting the normal brain PrP protein into the toxic, disease-related PrP form has started. At present, there is virtually no way to detect PrP reliably except by examining the brain using neuropathological and immunohistochemical methods after death. Accumulation of the abnormally folded PrP form of the PrP protein is a characteristic of the disease, but it is present at very low levels in easily accessible body fluids like blood or urine. Researchers have tried to develop methods to measure PrP, but there are still no fully accepted methods for use in materials such as blood.

In 2010, a team from New York described detection of PrP even when initially present at only one part in a hundred billion (10) in brain tissue. The method combines amplification with a novel technology called Surround Optical Fiber Immunoassay (SOFIA) and some specific antibodies against PrP. After amplifying and then concentrating any PrP, the samples are labelled with a fluorescent dye using an antibody for specificity and then finally loaded into a micro-capillary tube. This tube is placed in a specially constructed apparatus so that it is totally surrounded by optical fibres to capture all light emitted once the dye is excited using a laser. The technique allowed detection of PrP after many fewer cycles of conversion than others have achieved, substantially reducing the possibility of artefacts, as well as speeding up the assay. The researchers also tested their method on blood samples from apparently healthy sheep that went on to develop scrapie. The animals’ brains were analysed once any symptoms became apparent. The researchers could therefore compare results from brain tissue and blood taken once the animals exhibited symptoms of the diseases, with blood obtained earlier in the animals’ lives, and from uninfected animals. The results showed very clearly that PrP could be detected in the blood of animals long before the symptoms appeared.

Recent research from the University of Toronto and Caprion Pharmaceuticals has discovered one possible avenue that might lead to quicker diagnosis, a vaccine or possibly even treatment for prion diseases. The abnormally folded proteins that cause the disease have been found to expose a side chain of amino acids that the properly folded protein does not expose. Antibodies specifically coded to this side-chain amino acid sequence have been found to stimulate an immune response to the abnormal prions and leave the normal proteins intact.

Another idea involves using custom peptide sequences. Since some research suggests prions aggregate by forming beta barrel structures, work done "in vitro" has shown that peptides made up of beta barrel-incompatible amino acids can help break up accumulations of prion.

A third idea concerns genetic therapy, whereby the gene for encoding protease-resistant protein is considered to be an error in several species, and therefore something to be inhibited.

Most symptoms will improve quickly if deficiencies are treated early. Memory disorder may be permanent.

In patients suspected of WE, thiamine treatment should be started immediately. Blood should be immediately taken to test for thiamine, other vitamins and minerals levels. Following this an immediate intravenous or intramuscular dose of thiamine should be administered two or three times daily. Thiamine administration is usually continued until clinical improvement ceases.

Considering the diversity of possible causes and several surprising symptomatologic presentations, and because there is low assumed risk of toxicity of thiamine, because the therapeutic response is often dramatic from the first day, some qualified authors indicate parenteral thiamine if WE is suspected, both as a resource for diagnosis and treatment. The diagnosis is highly supported by the response to parenteral thiamine, but is not sufficient to be excluded by the lack of it. Parenteral thiamine administration is associated with a very small risk of anaphylaxis.

Alcohol abusers may have poor dietary intakes of several vitamins, and impaired thiamine absorption, metabolism, and storage; they may thus require higher doses.

If glucose is given, such as in hypoglycaemic alcoholics, thiamine must be given concurrently. If this is not done, the glucose will rapidly consume the remaining thiamine reserves, exacerbating this condition.

The observation of edema in MR, and also the finding of inflation and macrophages in necropsied tissues, has led to successful administration of antiinflammatories.

Other nutritional abnormalities should also be looked for, as they may be exacerbating the disease. In particular, magnesium, a cofactor of transketolase which may induce or aggravate the disease.

Other supplements may also be needed, including: cobalamin, ascorbic acid, folic acid, nicotinamide, zinc, phosphorus (dicalcium phosphate) and in some cases taurine, especially suitable when there cardiocirculatory impairment.

Patient-guided nutrition is suggested. In patients with Wernicke-Korsakoff syndrome, even higher doses of parenteral thiamine are recommended. Concurrent toxic effects of alcohol should also be considered.

Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, are a group of progressive, invariably fatal, conditions that affect the brain (encephalopathies) and nervous system of many animals, including humans. According to the most widespread hypothesis, they are transmitted by prions, though some other data suggest an involvement of a "Spiroplasma" infection. Mental and physical abilities deteriorate and myriad tiny holes appear in the cortex causing it to appear like a sponge (hence spongiform) when brain tissue obtained at autopsy is examined under a microscope. The disorders cause impairment of brain function, including memory changes, personality changes and problems with movement that worsen chronically.

Prion diseases of humans include Creutzfeldt–Jakob disease—which has four main forms, the sporadic (sCJD), the hereditary/familiar (fCJD), the iatrogenic (iCJD) and the variant form (vCJD)—Gerstmann–Sträussler–Scheinker syndrome, fatal familial insomnia, kuru, and the recently discovered variably protease-sensitive prionopathy. These conditions form a spectrum of diseases with overlapping signs and symptoms. TSEs in non-human mammals include scrapie in sheep, bovine spongiform encephalopathy (BSE)—popularly known as 'mad cow's disease'—in cattle and chronic wasting disease (CWD) in deer and elk. The variant form of Creutzfeldt–Jakob disease is caused by exposure to bovine spongiform encephalopathy prions.

Unlike other kinds of infectious disease, which are spread by agents with a DNA or RNA genome (such as virus or bacteria), the infectious agent in TSEs is believed to be a prion, thus being composed solely of protein material. Misshapen prion proteins carry the disease between individuals and cause deterioration of the brain. TSEs are unique diseases in that their aetiology may be genetic, sporadic, or infectious via ingestion of infected foodstuffs and via iatrogenic means (e.g., blood transfusion). Most TSEs are sporadic and occur in an animal with no prion protein mutation. Inherited TSE occurs in animals carrying a rare mutant prion allele, which expresses prion proteins that contort by themselves into the disease-causing conformation. Transmission occurs when healthy animals consume tainted tissues from others with the disease. In the 1980s and 1990s, bovine spongiform encephalopathy (BSE) spread in cattle in an epidemic fashion. This occurred because cattle were fed the processed remains of other cattle, a practice now banned in many countries. In turn, consumption (by humans) of bovine-derived foodstuff which contained prion-contaminated tissues resulted in an outbreak of the variant form of Creutzfeldt–Jakob disease in the 1990s and 2000s.

Prions cannot be transmitted through the air or through touching or most other forms of casual contact. However, they may be transmitted through contact with infected tissue, body fluids, or contaminated medical instruments. Normal sterilization procedures such as boiling or irradiating materials fail to render prions non-infective.

Variant Creutzfeldt–Jakob disease (vCJD) or new variant Creutzfeldt–Jakob disease (nvCJD) is a transmissible spongiform encephalopathy which was identified in 1996 by the National CJD Surveillance Unit in Edinburgh, Scotland. It is always fatal and is caused by prions, which are mis-folded proteins. Over 170 cases of vCJD have been recorded in the United Kingdom, and around 30 cases in the rest of the world. The fact that the epidemiology of the disease coincided with an epidemic of bovine spongiform encephalopathy led to the hypothesis that consumption of BSE-infected beef caused the disease. It is a different disease from Sporadic and Familial Creutzfeldt–Jakob disease, though it is believed to be caused by the same pathogenic agent, a mis-folded protein, known as a prion.

Despite the consumption of contaminated beef in the UK being reckoned to be quite high, vCJD has infected a comparatively small cohort of people. One explanation for this can be found in the genetics of patients with the disease. The human PRNP protein which is subverted in prion disease can occur with either methionine or valine at amino acid 129, without any apparent difference in normal function. Of the overall Caucasian population, about 40% have two methionine-containing alleles, 10% have two valine-containing alleles, and the other 50% are heterozygous at this position. Only a single vCJD patient tested was found to be heterozygous; most of those affected had two copies of the methionine-containing form. Additionally, for unknown reasons, those affected are generally under the age of 40. It is not yet known whether those unaffected are actually immune or only have a longer incubation period until symptoms appear.

Transmissible mink encephalopathy (TME) is a rare sporadic disease that affects the central nervous system of ranch-raised mink. It is classified as a transmissible spongiform encephalopathy, believed to be caused by proteins called prions. This disease is only known to affect adult mink.

There is currently no specific therapy. Intravenous fluids and treatment of the hepatic encephalopathy may help. Increasing dietary levels of branched chain amino acids and feeding low protein diets can help signs of hepatic encephalopathy, which is often accomplished by feeding small amounts of grain and/or beet pulp, and removing high-protein feedstuffs such as alfalfa hay. Grazing on non-legume grass may be acceptable if it is late summer or fall, although the horse should only be permitted to eat in the evening so as to avoid photosensitization. Due to the risk of gastric impaction, stomach size should be monitored.

Sedation is minimized and used only to control behavior that could lead to injury of the animal and to allow therapeutic procedures, and should preferably involve a sedative other than a benzodiazepine. Stressing the animal should be avoided if at all possible. Plasma transfusions may be needed if spontaneous bleeding occurs, to replace clotting factors. Antibiotics are sometimes prescribed to prevent bacterial translocation from the intestines. Antioxidants such as vitamin E, B-complex vitamins, and acetylcysteine may be given. High blood ammonia is often treated with oral neomycin, often in conjunction with lactulose, metronidazole and probiotics, to decrease production and absorption of ammonia from the gastrointestinal tract.

A slow virus is a virus, or a viruslike agent, etiologically associated with a disease, having a long incubation period of months to years and then a gradual onset of symptoms which progress slowly but irreversibly and terminate in a severe compromised state or, more commonly, death.

A slow virus disease is a disease that, after an extended period of latency, follows a slow, progressive course spanning months to years, frequently involving the central nervous system and ultimately leading to death. Examples include the Visna-Maedi virus, in the genus Lentivirus (family Retroviridae), that causes encephalitis and chronic pneumonitis in sheep, and subacute sclerosing panencephalitis which is apparently caused by the measles virus, as well as Paget's Disease of Bone (Osteitis Deformans) which is associated with paramyxoviridae, especially RSV and Rubeola (Measles).

Although no specific treatment exists, the disease can be managed with anticonvulsants, physiotherapy, etc.

There are hospital protocols for prevention, supplementing with thiamine in the presence of: history of alcohol misuse or related seizures, requirement for IV glucose, signs of malnutrition, poor diet, recent diarrhea or vomiting, peripheral neuropathy, intercurrent illness, delirium tremens or treatment for DTs, and others. Some experts advise parenteral thiamine should be given to all at-risk patients in the emergency room.

In the clinical diagnosis should be remembered that early symptoms are nonspecific, and it has been stated that WE may present nonspecific findings. There is consensus to provide water-soluble vitamins and minerals after gastric operations.

In some countries certain foods have been supplemented with thiamine, and have reduced WE cases. Improvement is difficult to quantify because they applied several different actions. Avoiding alcohol and having adequate nutrition reduces one of the main risk factors in developing Wernicke-Korsakoff syndrome.

A preparation of "L"-ornithine and "L"-aspartate (LOLA) is used to increase the generation of urea through the urea cycle, a metabolic pathway that removes ammonia by turning it into the neutral substance urea. It may be combined with lactulose and/or rifaximin if these alone are ineffective at controlling symptoms.

There is no specific treatment for the condition.

Control may rely on boosting bird immunity, preventing group mixing and faecal spreading.

The antibiotic rifaximin may be recommended in addition to lactulose for those with recurrent disease. It is a nonabsorbable antibiotic from the rifamycin class. This is thought to work in a similar way to other antibiotics, but without the complications attached to neomycin or metronidazole. Due to the long history and lower cost of lactulose use, rifaximin is generally only used as a second-line treatment if lactulose is poorly tolerated or not effective. When rifaximin is added to lactulose, the combination of the two may be more effective than each component separately. Rifaximin is more expensive than lactulose, but the cost may be offset by reduced hospital admissions for encephalopathy.

The antibiotics neomycin and metronidazole are other antibiotics used to treat hepatic encephalopathy. The rationale of their use was the fact that ammonia and other waste products are generated and converted by intestinal bacteria, and killing these bacteria would reduce the generation of these waste products. Neomycin was chosen because of its low intestinal absorption, as neomycin and similar aminoglycoside antibiotics may cause hearing loss and kidney failure if used by injection. Later studies showed that neomycin was indeed absorbed when taken by mouth, with resultant complications. Metronidazole, similarly, is less commonly used because prolonged use can cause nerve damage, in addition to gastrointestinal side effects.

This illness has a minimum incubation period of 7 months with a maximum of 12 months. This disease results in mortality of adult animals.

Clinical signs of TME include the characteristic behavioural changes such as confusion, loss of cleanliness, and aimless circling. An affected animal shows signs of weight loss, might develop matted fur, hindquarter ataxia, and its tail arched over its back. Seizures may very rarely occur. Near-death stages include the animal showing signs of drowsiness and unresponsiveness.

Currently, no tests are available to detect signs of this illness in live animals. However, veterinary pathologists can confirm this illness by microscopic examination of the brain tissue in animals suspected to have died of this disease, where they expect to detect areas of distinct sponge-like formations, or by the identification of the prion protein in these tissue samples.

As described, Korsakoff 's syndrome usually follows or accompanies Wernicke's encephalopathy. If treated quickly, it may be possible to prevent the development of Korsakoff's syndrome with thiamine treatments. This treatment is not guaranteed to be effective and the thiamine needs to be administered adequately in both dose and duration. A study on Wernicke-Korsakoff's syndrome showed that with consistent thiamine treatment there were noticeable improvements in mental status after only 2–3 weeks of therapy. Thus, there is hope that with treatment Wernicke's encephalopathy will not necessarily progress to WKS.

In order to reduce the risk of developing WKS it is important to limit the intake of alcohol or drink in order to ensure that proper nutrition needs are met. A healthy diet is imperative for proper nutrition which, in combination with thiamine supplements, may reduce the chance of developing WKS. This prevention method may specifically help heavy drinkers who refuse to or are unable to quit.

Every infectious agent is different, but in general, slow viruses:

Additionally, the immune system seems to plays a limited role, or no role, in protection from these slow viruses. This may be in part because the host has acclimated to the virus, or more likely because the host must be immunocompromised in order for many of these slow virus infections to emerge, so the immune system is at a disadvantage from the start.

The onset of Wernicke's encephalopathy is considered a medical emergency, and thus thiamine administration should be initiated immediately when the disease is suspected. Prompt administration of thiamine to patients with Wernicke's encephalopathy can prevent the disorder from developing into Wernicke–Korsakoff syndrome, or reduce its severity. Treatment can also reduce the progression of the deficits caused by WKS, but will not completely reverse existing deficits. WKS will continue to be present, at least partially, in 80% of patients. Patients suffering from WE should be given a minimum dose of 500 mg of thiamine hydrochloride, delivered by infusion over a 30-minute period for two to three days. If no response is seen then treatment should be discontinued but for those patients that do respond, treatment should be continued with a 250 mg dose delivered intravenously or intramuscularly for three to five days unless the patient stops improving. Such prompt administration of thiamine may be a life-saving measure. Banana bags, a bag of intravenous fluids containing vitamins and minerals, is one means of treatment.

Like diagnosis, treating CSE is difficult due to how vaguely defined it is, as well as lack of data on the mechanism of CSE effects on neural tissue. There is no existing treatment that is effective at completely recovering any neurological or physical function lost due to CSE. This is believed to be because of the limited regeneration capabilities in the central nervous system. Furthermore, existing symptoms of CSE can potentially worsen with age. Some symptoms of CSE, such as depression and sleep issues, can be treated separately, and therapy is available to help patients adjust to any disabilities. Current treatment for CSE involves treating accompanying psychopathology, symptoms, and preventing further deterioration.

In the past, treatment options were limited to supportive medical therapy. Nowadays neonatal encephalopathy is treated using hypothermia therapy.

Response to treatment is variable and the long-term and functional outcome is unknown. To provide a basis for improving the understanding of the epidemiology, genotype/phenotype correlation and outcome of these diseases their impact on the quality of life of patients, and for evaluating diagnostic and therapeutic strategies a patient registry was established by the noncommercial International Working Group on Neurotransmitter Related Disorders (iNTD).