No controlled clinical trials have been conducted on ADEM treatment, but aggressive treatment aimed at rapidly reducing inflammation of the CNS is standard. The widely accepted first-line treatment is high doses of intravenous corticosteroids, such as methylprednisolone or dexamethasone, followed by 3–6 weeks of gradually lower oral doses of prednisolone. Patients treated with methylprednisolone have shown better outcomes than those treated with dexamethasone. Oral tapers of less than three weeks duration show a higher chance of relapsing, and tend to show poorer outcomes. Other anti-inflammatory and immunosuppressive therapies have been reported to show beneficial effect, such as plasmapheresis, high doses of intravenous immunoglobulin (IVIg), mitoxantrone and cyclophosphamide. These are considered alternative therapies, used when corticosteroids cannot be used or fail to show an effect.

There is some evidence to suggest that patients may respond to a combination of methylprednisolone and immunoglobulins if they fail to respond to either separately

In a study of 16 children with ADEM, 10 recovered completely after high-dose methylprednisolone, one severe case that failed to respond to steroids recovered completely after IV Ig; the five most severe cases -with ADAM and severe peripheral neuropathy- were treated with combined high-dose methylprednisolone and immunoglobulin, two remained paraplegic, one had motor and cognitive handicaps, and two recovered. A recent review of IVIg treatment of ADEM (of which the previous study formed the bulk of the cases) found that 70% of children showed complete recovery after treatment with IVIg, or IVIg plus corticosteroids. A study of IVIg treatment in adults with ADEM showed that IVIg seems more effective in treating sensory and motor disturbances, while steroids seem more effective in treating impairments of cognition, consciousness and rigor. This same study found one subject, a 71-year-old man who had not responded to steroids, that responded to an IVIg treatment 58 days after disease onset.

Since each case is different, the following are possible treatments that patients might receive in the management of myelitis.

- Intravenous steroids

High-dose intravenous methyl-prednisolone for 3–5 days is considered as a standard of care for patients suspected to have acute myelitis, unless there are compelling reasons otherwise. The decision to offer continued steroids or add a new treatment is often based on the clinical course and MRI appearance at the end of 5 days of steroids.

- Plasma exchange (PLEX)

Patients with moderate to aggressive forms of disease who don’t show much improvement after being treated with intravenous and oral steroids will be treated with PLEX. Retrospective studies of patients with TM treated with IV steroids followed by PLEX showed a positive outcome. It also has been shown to be effective with other autoimmune or inflammatory central nervous system disorders. Particular benefit has been shown with patients who are in the acute or subacute stage of the myelitis showing active inflammation on MRI. However, because of the risks implied by the lumbar puncture procedure, this intervention is determined by the treating physician on a case-by-case basis.

- Immunosuppressants/Immunomodulatory agents

Myelitis with no definite cause seldom recurs, but for others, myelitis may be a manifestation of other diseases that are mentioned above. In these cases, ongoing treatment with medications that modulate or suppress the immune system may be necessary. Sometimes there is no specific treatment. Either way, aggressive rehabilitation and long-term symptom management are an integral part of the healthcare plan.

At the time of the report there was no known treatment for the disease; specifically, it was not established whether steroids were helpful or harmful. Other techniques such as plasmaphoresis, intravenous immunoglobulin, and experimental antiviral drugs have been attempted on a trial basis, but have not been reported to be effective. On November 7 the CDC issued "Interim Considerations for Clinical Management of Patients with Acute Flaccid Myelitis", based on "consensus guidance drawn from experts in infectious diseases, neurology, pediatrics, critical care medicine, public health epidemiology and virology." Mark Sawyer of the American Academy of Pediatrics, who contributed to the guidance, was quoted by the organization's newsletter: The most important issue summarized in the document is that there is no clear evidence that therapies intended to modify the immune system (e.g., corticosteroids, immune globulin, plasmapheresis) have a beneficial effect in this condition. Plasmapheresis is specifically not recommended because the potential for harm is significant in the absence of any evidence of benefit.

Treatment (which is based on supportive care) is as follows:

Pyrimethamine-based maintenance therapy is often used to treat Toxoplasmic Encephalitis (TE), which is caused by Toxoplasma gondii and can be life-threatening for people with weak immune systems. The use of highly active antiretroviral therapy (HAART), in conjunction with the established pyrimethamine-based maintenance therapy, decreases the chance of relapse in patients with HIV and TE from approximately 18% to 11%. This is a significant difference as relapse may impact the severity and prognosis of disease and result in an increase in healthcare expenditure.

Limbic encephalitis is a rare condition with no randomised-controlled trials to guide treatment. Treatments that have been tried include intravenous immunoglobulin, plasmapheresis, corticosteroids, cyclophosphamide and rituximab.

If an associated tumour is found, then recovery is not possible until the tumour is removed. Unfortunately, this is not always possible, especially if the tumour is malignant and advanced.

Six of ten children in Denver were sent home for outpatient treatment; some with mild symptoms have recovered from temporary limb weakness, while the fate of those more severely affected remains unclear. Intensive physical therapy and occupational therapy may be beneficial for recovery.

Attacks are treated with short courses of high dosage intravenous corticosteroids such as methylprednisolone IV.

Plasmapheresis can be an effective treatment when attacks progress or do not respond to corticosteroid treatment. Clinical trials for these treatments contain very small numbers, and most are uncontrolled, though some report high success percentage.

Should the viral progression be diagnosed during stage 1 (even during late stage 1 when stage 2 symptoms start to manifest themselves) then treatment to combat the infection can be administered successfully—there is no cure for SSPE but if it is caught early enough then the sufferer can respond to the treatment and prevent symptom recurrence by taking the medication for the rest of their life. The treatment for the SSPE infection is the immunomodulator interferon and specific antiviral medication—ribavirin and inosine pranobex are specifically used to greater effect than antivirals such as amantadine.

For those who have progressed to stage 2 or beyond, the disease is incurable. For patients in the terminal phase of the disease there is a palliative care and treatment scheme—this involves anticonvulsant therapy (to help with the body's progressive loss of control of the nervous system causing gradually more intensive spasms/convulsions) alongside supportive measures to help maintain vital functioning. It is fairly standard as the infection spreads and symptoms intensify that feeding tubes need to be inserted to keep a nutritional balance. As the disease progresses to its most advanced phase, the patient will need constant nursing as normal bodily function declines to the complete collapse of the nervous system.

Combinations of treatment for SSPE include:

- Oral inosine pranobex (oral isoprinosine) combined with intrathecal (injection through a lumbar puncture into the spinal fluid) or intraventricular interferon alpha.

- Oral inosine pranobex (oral isoprinosine) combined with interferon beta.

- Intrathecal interferon alpha combined with intravenous ribavirin.

No controlled trials have established the effectiveness of treatments for the prevention of attacks. Many clinicians agree that long term immunosuppression is required to reduce the frequency and severity of attacks, while others argue the exact opposite. Commonly used immunosuppressant treatments include azathioprine (Imuran) plus prednisone, mycophenolate mofetil plus prednisone, mitoxantrone, intravenous immunoglobulin (IVIG), and cyclophosphamide.

Though the disease is known to be auto-antibodies mediated, B-cell depletion has been tried with the monoclonal antibody rituximab, showing good results.

Several other disease modifying therapies are being tried. In 2007, Devic's disease was reported to be responsive to glatiramer acetate and to low-dose corticosteroids. Use of Mycophenolate mofetil is also currently under research.

Vaccination is available against tick-borne and Japanese encephalitis and should be considered for at-risk individuals. Post-infectious encephalomyelitis complicating smallpox vaccination is avoidable, for all intents and purposes, as smallpox is nearly eradicated. Contraindication to Pertussis immunization should be observed in patients with encephalitis.

Central nervous system nerve regeneration would be able to repair or regenerate the damage caused to the spinal cord. It would restore functions lost due to the disease.

- Engineering endogenous repair

Currently, there exists a hydrogel based scaffold which acts as a channel to deliver nerve growth-enhancing substrates while providing structural support. These factors would promote nerve repairs to the target area. Hydrogels' macroporous properties would enable attachment of cells and enhance ion and nutrient exchange. In addition, hydrogels' biodegradability or bioresolvability would prevent the need for surgical removal of the hydrogel after drug delivery. It means that it would be dissolved naturally by the body's enzymatic reaction.

- Biochemical repair

- Stem cell based therapies

The possibility for nerve regeneration after injury to the spinal cord was considered to be limited because of the absence of major neurogenesis. However, Joseph Altman showed that cell division does occur in the brain which allowed potential for stem cell therapy for nerve regeneration. The stem cell-based therapies are used in order to replace cells lost and injured due to inflammation, to modulate the immune system, and to enhance regeneration and remyelination of axons. Neural stem cells (NSC) have the potential to integrate with the spinal cord because in the recent past investigations have demonstrated their potential for differentiation into multiple cell types that are crucial to the spinal cord. Studies show that NSCs that were transplanted into a demyelinating spinal cord lesion were found to regenerate oligodendrocytes and Schwann cells, and completely remyelinated axons.

Treatments of proven efficacy are currently limited mostly to herpes viruses and human immunodeficiency virus. The herpes virus is of two types: herpes type 1 (HSV-1, or oral herpes) and herpes type 2 (HSV-2, or genital herpes). Although there is no particular cure; there are treatments that can relieve the symptoms. Drugs like Famvir, Zovirax, and Valtrex are among the drugs used, but these medications can only decrease pain and shorten the healing time. They can also decrease the total number of outbreaks in the surrounding. Warm baths also may relive the pain of genital herpes.

Human Immunodeficiency Virus Infection (HIV) is treated by using a combination of medications to fight against the HIV infection in the body. This is called antiretroviral therapy (ART). ART is not a cure, but it can control the virus so that a person can live a longer, healthier life and reduce the risk of transmitting HIV to others around him. ART involves taking a combination of HIV medicines (called an HIV regimen) every day, exactly as prescribed by the doctor. These HIV medicines prevent HIV Virus from multiplying (making copies of itself in the body), which reduces the amount of HIV in the body. Having less HIV in the body gives the immune system a chance to recover and fight off infections and cancers. Even though there is still some HIV in the body, the immune system is strong enough to fight off infections and cancers. By reducing the amount of HIV in the body, HIV medicines also reduce the risk of transmitting the virus to others. ART is recommended for all people with HIV, regardless of how long they’ve had the virus or how healthy they are. If left untreated, HIV will attack the immune system and eventually progress to AIDS.

Development of new therapies has been hindered by the lack of appropriate animal model systems for some important viruses and also because of the difficulty in conducting human clinical trials for diseases that are rare. Nonetheless, numerous innovative approaches to antiviral therapy are available including candidate thiazolide and purazinecarboxamide derivatives with potential broad-spectrum antiviral efficacy. New herpes virus drugs include viral helicase-primase and terminase inhibitors. A promising new area of research involves therapies based on enhanced understanding of host antiviral immune responses.

In the US, neuroborreliosis is typically treated with intravenous antibiotics which cross the blood–brain barrier, such as penicillins, ceftriaxone, or cefotaxime. One relatively small randomized controlled trial suggested ceftriaxone was more effective than penicillin in the treatment of neuroborreliosis. Small observational studies suggest ceftriaxone is also effective in children. The recommended duration of treatment is 14 to 28 days.

Several studies from Europe have suggested oral doxycycline is equally as effective as intravenous ceftriaxone in treating neuroborreliosis. Doxycycline has not been widely studied as a treatment in the US, but antibiotic sensitivities of prevailing European and US isolates of "Borrelia burgdorferi" tend to be identical. However, doxycycline is generally not prescribed to children due to the risk of bone and tooth damage.

Discreditied or doubtful treatments for neuroborreliosis include:

- Malariotherapy

- Hyperbaric oxygen therapy

- Colloidal silver

- Injections of hydrogen peroxide and bismacine

Experimental allergic encephalomyelitis (EAE) is an animal model of CNS inflammation and demyelination frequently used to investigate potential MS treatments. An acute monophasic illness, EAE is far more similar to ADEM than MS.

During the acute stage, treatment is aimed at reducing the inflammation. As in other inflammatory diseases, steroids may be used first of all, either as a short course of high-dose treatment, or in a lower dose for long-term treatment. Intravenous immunoglobulin is also effective both in the short term and in the long term, particularly in adults where it has been proposed as first-line treatment. Other similar treatments include plasmapheresis and tacrolimus, though there is less evidence for these. None of these treatments can prevent permanent disability from developing.

During the residual stage of the illness when there is no longer active inflammation, treatment is aimed at improving the remaining symptoms. Standard anti-epileptic drugs are usually ineffective in controlling seizures, and it may be necessary to surgically remove or disconnect the affected cerebral hemisphere, in an operation called hemispherectomy. This usually results in further weakness, hemianopsia and cognitive problems, but the other side of the brain may be able to take over some of the function, particularly in young children. The operation may not be advisable if the left hemisphere is affected, since this hemisphere contains most of the parts of the brain that control language. However, hemispherectomy is often very effective in reducing seizures.

In the classic presentation of the disease death usually occurs within 3 years, however there are rarely both fast and slower progressions. Faster deterioration in cases of acute fulminant SSPE leads to death within 3 months of diagnosis.

If the diagnosis is made during stage 1 of the SSPE infection then it may be possible to treat the disease with oral isoprinosine (Inosiplex) and intraventricular interferon alfa, but the response to these drugs varies from patient to patient. However, once SSPE progresses to stage 2 then it is universally fatal in all occurrences. The standard rate of decline spans anywhere between 1–3 years after the onset of the infection. The progression of each stage is unique to the sufferer and cannot be predicted although the pattern or symptoms/signs can be.

Although the prognosis is bleak for SSPE past stage 1, there is a 5% spontaneous remission rate—this may be either a full remission that may last many years or an improvement in condition giving a longer progression period or at least a longer period with the less severe symptoms.

Encephalomyelitis is inflammation of the brain and spinal cord. Various types of encephalomyelitis include:

- "Acute disseminated encephalomyelitis" or "postinfectious encephalomyelitis", a demyelinating disease of the brain and spinal cord, possibly triggered by viral infection.

- "Encephalomyelitis disseminata", a synonym for multiple sclerosis.

- "AntiMOG associated encephalomyelitis", one of the underlying conditions for the phenotype neuromyelitis optica and in general all the spectrum of MOG autoantibody-associated demyelinating diseases.

- "Equine encephalomyelitis", also called "equine encephalitis", a potentially fatal mosquito-borne viral disease that infects horses and humans.

- "Myalgic encephalomyelitis", a disease involving presumed inflammation of the central nervous system with symptoms of muscle pain and fatigue; the term has sometimes been used interchangeably with "chronic fatigue syndrome", though there is still controversy over the distinction.

- "Experimental autoimmune encephalomyelitis" (EAE), an animal model of brain inflammation.

- Progressive encephalomyelitis with rigidity and myoclonus (PERM) – A kind of stiff person syndrome.

- AIDS related encephalomyelitis, caused by opportunistic Human T-lymphotropic virus type III (HTLV-III) infection.

Given that some conditions as MS show cortical damage together with the WM damage, there has been interest if this can appear as a secondary damage of the WM. It seems that some researchers claim so.

Typical tumefactive lesions have been found to be responsive to corticosteroids because of their immunosuppressive and anti-inflammatory properties. They restore the blood-brain barrier and induce cell death of T-cells.

No standard treatment exists, but practitioners seem to apply intravenous corticosteroids, followed by plasmapheresis and cyclophosphamide in non-responsive cases High dose intravenous corticosteroids (methylprednisolone 1 g for 3–5 days) followed by oral tapering hasten clinical and radiological improvement in approximately 80% of patients

Plasmapheresis has been reported to work even in the absence of response to corticosteroids

Fatigue is a common symptom and affects the daily life of individuals with MS. Changes in lifestyle are usually recommended to reduce fatigue. These include taking frequent naps and implementing exercise. MS patients who smoke are also advised to stop. Pharmacological treatment include anti-depressants and caffeine. Aspirin has also been experimented with and from clinical trial data, MS patients preferred using aspirin as compared to the placebo in the test. One hypothesis is that aspirin has an effect on the hypothalamus and can affect the perception of fatigue through altering the release of neurotransmitters and the autonomic responses.

As of 2017, eleven disease-modifying medications have been approved by regulatory agencies for relapsing-remitting multiple sclerosis (RRMS). They are interferon beta-1a, interferon beta-1b, glatiramer acetate, mitoxantrone, natalizumab, fingolimod, teriflunomide, dimethyl fumarate, alemtuzumab, daclizumab, and ocrelizumab.

Their cost effectiveness as of 2012 is unclear. In May 2016 the FDA approved daclizumab for the treatment of relapsing multiple sclerosis in adults, with requirements for postmarketing studies and submission of a formal risk evaluation and mitigation strategy. In March 2017 the FDA approved ocrelizumab, a humanized anti-CD20 monoclonal antibody, as a treatment for RRMS, with requirements for several Phase IV clinical trials.

In RRMS they are modestly effective at decreasing the number of attacks. The interferons and glatiramer acetate are first-line treatments and are roughly equivalent, reducing relapses by approximately 30%. Early-initiated long-term therapy is safe and improves outcomes. Natalizumab reduces the relapse rate more than first-line agents; however, due to issues of adverse effects is a second-line agent reserved for those who do not respond to other treatments or with severe disease. Mitoxantrone, whose use is limited by severe adverse effects, is a third-line option for those who do not respond to other medications. Treatment of clinically isolated syndrome (CIS) with interferons decreases the chance of progressing to clinical MS. Efficacy of interferons and glatiramer acetate in children has been estimated to be roughly equivalent to that of adults. The role of some newer agents such as fingolimod, teriflunomide, and dimethyl fumarate, as of 2011, is not yet entirely clear.

As of 2017, rituximab was widely used off-label to treat RRMS.

Immunosuppressive therapies, encompassing corticosteroids, azathioprine, methotrexate and more recently, rituximab, are the mainstay of therapy. Other treatments include PE, IVIG, and thymectomy. Patients reportedly exhibited a heterogenous response to immunomodulation.

Antiepileptics can be used for symptomatic relief of peripheral nerve hyperexcitability. Indeed, some patients have exhibited a spontaneous remission of symptoms.

Experimental autoimmune encephalomyelitis, sometimes experimental allergic encephalomyelitis (EAE) is an animal model of brain inflammation. It is an inflammatory demyelinating disease of the central nervous system (CNS). It is mostly used with rodents and is widely studied as an animal model of the human CNS demyelinating diseases, including multiple sclerosis and acute disseminated encephalomyelitis (ADEM). EAE is also the prototype for T-cell-mediated autoimmune disease in general.

EAE was motivated by observations during the convalescence from viral diseases by Thomas M. Rivers, D. H. Sprunt and G. P. Berry in 1933. Their findings upon a transfer of inflamed patient tissue to primates was published in the "Journal of Experimental Medicine". An acute monophasic illness, it has been suggested that EAE is far more similar to ADEM than MS.

EAE can be induced in a number of species, including mice, rats, guinea pigs, rabbits and primates. The most commonly used antigens in rodents are spinal cord homogenate (SCH), purified myelin, myelin protein such as MBP, PLP, and MOG, or peptides of these proteins, all resulting in distinct models with different disease characteristics regarding both immunology and pathology. It may also be induced by the passive transfer of T cells specifically reactive to these myelin antigens.

Depending on the antigen used and the genetic make-up of the animal, rodents can display a monophasic bout of EAE, a relapsing-remitting form, or chronic EAE. The typical susceptible rodent will debut with clinical symptoms around two weeks after immunization and present with a relapsing-remitting disease. The archetypical first clinical symptom is weakness of tail tonus that progresses to paralysis of the tail, followed by a progression up the body to affect the hind limbs and finally the forelimbs. However, similar to MS, the disease symptoms reflect the anatomical location of the inflammatory lesions, and may also include emotional lability, sensory loss, optic neuritis, difficulties with coordination and balance (ataxia), and muscle weakness and spasms. Recovery from symptoms can be complete or partial and the time varies with symptoms and disease severity. Depending on the relapse-remission intervals, rats can have up to 3 bouts of disease within an experimental period.

As of 2017, rituximab has been widely used off-label to treat progressive primary MS. In March 2017 the FDA approved ocrelizumab, as a treatment for primary progressive MS, the first drug to gain that approval, with requirements for several Phase IV clinical trials.

, only one medication, mitoxantrone, has been approved for secondary progressive MS. In this population tentative evidence supports mitoxantrone moderately slowing the progression of the disease and decreasing rates of relapses over two years.