In 1982 Lewis et al reported a group of patients with a chronic asymmetrical sensorimotor neuropathy mostly affecting the arms with multifocal involvement of peripheral nerves. Also in 1982 Dyck "et al" reported a response to prednisolone to a condition they referred to as chronic inflammatory demyelinating polyradiculoneuropathy. Parry and Clarke in 1988 described a neuropathy which was later found to be associated with IgM autoantibodies directed against GM1 gangliosides. This latter condition was later termed multifocal motor neuropathy This distinction is important because multifocal motor neuropathy responds to intravenous globulin alone while chronic inflammatory demyelinating polyneuropathy responds to intravenous globulin, steroids and plasma exchanges. It has been suggested that multifocal motor neuropathy is distinct from chronic inflammatory demyelinating polyneuropathy and that Lewis-Summer syndrome is a distinct variant type of chronic inflammatory demyelinating polyneuropathy.

The Lewis-Summer form of this condition is considered a rare disease with only 50 cases reported up to 2004. A total of 90 cases had been reported by 2009

Chronic inflammatory demyelinating polyneuropathy, also known as Vidaurri's disease, is believed to be due to immune cells, which normally protect the body from foreign infection, incorrectly attacking the nerves in the body instead. As a result, the affected nerves fail to respond, or respond only weakly, and on occasion, inordinately, to stimuli, causing numbing, tingling, pain, progressive muscle weakness, loss of deep tendon reflexes (areflexia), fatigue, and abnormal sensations. The likelihood of progression of the disease is high.

CIDP is under-recognized and under-treated due to its heterogeneous presentation (both clinical and electrophysiological) and the limitations of clinical, serologic, and electrophysiologic diagnostic criteria. Despite these limitations, early diagnosis and treatment is important in preventing irreversible axonal loss and improving functional recovery.

Lack of awareness and treatment of CIDP is also due to limitations of clinical trials. Although there are stringent research criteria for selecting patients to clinical trials, there are no generally agreed-on clinical diagnostic criteria for CIDP due to its different presentations in symptoms and objective data. Application of the present research criteria to routine clinical practice often miss the diagnosis in a majority of patients, and patients are often left untreated despite progression of their disease.

The role of prolonged cortical myelination in human evolution has been implicated as a contributing factor in some cases of demyelinating disease. Unlike other primates, humans exhibit a unique pattern of postpubertal myelination, which may contribute to the development of psychiatric disorders and neurodegenerative diseases that present in early adulthood and beyond. The extended period of cortical myelination in humans may allow greater opportunity for disruption in myelination, resulting in the onset of demyelinating disease. Furthermore, it has been noted that humans have significantly greater prefrontal white matter volume than other primate species, which implies greater myelin density. Increased myelin density in humans as a result of a prolonged myelination may therefore structure risk for myelin degeneration and dysfunction. Evolutionary considerations for the role of prolonged cortical myelination as a risk factor for demyelinating disease are particularly pertinent given that genetics and autoimmune deficiency hypotheses fail to explain many cases of demyelinating disease. As has been argued, diseases such as multiple sclerosis cannot be accounted for by autoimmune deficiency alone, but strongly imply the influence of flawed developmental processes in disease pathogenesis. Therefore, the role of the human-specific prolonged period of cortical myelination is an important evolutionary consideration in the pathogenesis of demyelinating disease.

Prognosis depends on the condition itself. Some conditions such as multiple sclerosis depend on the subtype of the disease and various attributes of the patient such as age, sex, initial symptoms and the degree of disability the patient experiences. Life expectancy in Multiple sclerosis patients is 5 to 10 years lower than unaffected people. MS is an inflammatory demyelinating disease of the

central nervous system (CNS) that develops in genetically susceptible individuals after exposure to unknown environmental trigger(s). The bases for MS are unknown but are strongly suspected to involve immune reactions against autoantigens, particularly myelin proteins. The most accepted hypothesis is that dialogue between T-cell receptors and myelin antigens leads to an immune attack on the myelin-oligodendrocyte complex. These interactions between active T cells and myelin antigens provoke a massive destructive inflammatory response and promotes continuing proliferation of T and B cells and macrophage activation, which sustains secretion of inflammatory mediators. Other conditions such as central pontine myelinolysis have about a third of patients recover and the other two thirds experience varying degrees of disability. There are cases, such as transverse myelitis where the patient can begin recovery as early as 2 to 12 weeks after the onset of the condition.

Normally, some measure of improvement appears in a few weeks, but residual signs and disability may persist, sometimes severely.

The disease can be monophasic, i.e. a single episode with permanent remission. However, at least 85% of patients have a relapsing form of the disease with repeated attacks of transverse myelitis and/or optic neuritis. In patients with the monophasic form, the transverse myelitis and optic neuritis occur simultaneously or within days of each other. On the other hand, patients with the relapsing form are more likely to have weeks or months between the initial attacks, and to have better motor recovery after the initial transverse myelitis event. Relapses usually occur early, with about 55% of patients having a relapse in the first year and 90% in the first five years.

It is possible that the relapsing form is related to the antiAQP4+ seropositive status and the monophasic form related to its absence Unlike multiple sclerosis, Devic's disease rarely has a secondary progressive phase in which patients have increasing neurologic decline between attacks without remission. Instead, disabilities arise from the acute attacks.

Approximately 20% of patients with monophasic Devic's disease have permanent visual loss, and 30% have permanent paralysis in one or both legs. Among patients with relapsing Devic's disease, 50% have paralysis or blindness within five years. In some patients (33% in one study), transverse myelitis in the cervical spinal cord resulted in respiratory failure and subsequent death. However, the spectrum of Devic's disease has widened due to improved diagnostic criteria, and the options for treatment have improved; as a result, researchers believe these estimates will be lowered.

The causes of polyneuropathy can be divided into hereditary and acquired and are therefore as follows:

- "Inherited" -are hereditary motor neuropathies, Charcot–Marie–Tooth disease, and hereditary neuropathy with liability to pressure palsy

- "Acquired" -are diabetes mellitus, vascular neuropathy, alcohol abuse, and Vitamin B12 deficiency

Among the signs/symptoms of polyneuropathy, which can be divided (into sensory and hereditary) and are consistent with the following:

- "Sensory polyneuropathy" - ataxia, numbness, muscle wasting and paraesthesiae.

- "Hereditary polyneuropathy" - scoliosis and hammer toes

The prevalence and incidence of Devic's disease has not been established, partly because the disease is underrecognized and often confused with MS. Devic's disease is more common in women than men, with women comprising over two-thirds of patients and more than 80% of those with the relapsing form of the disease.

A retrospective study found that prevalence of NMOsd was 1.5% inside a random sample of neurological patients, with a MS:NMOsd ratio of 42.7. Among 13 NMOsd patients, 77% had long spinal cord lesions, 38% had severe optic neuritis and 23% had brain or brainstem lesions. Only 56% had clinically definite NMO at follow-up.

According to the Walton Centre in England, "NMO seems to be present across the world unlike MS, which has a higher incidence in temperate climates and white races. Africans and Asians especially in Far East may have a higher risk of NMO, although the exact incidence of this disease is unknown, making specific conclusions difficult". Although many people who have Devic's disease were initially misdiagnosed with MS, 35% of African Americans are often misdiagnosed with MS when they really have NMO.

Devic's disease is more common in Asians than Caucasians. In fact, Asian optic-spinal MS (which constitutes 30% of the cases of MS in Japan) has been suggested to be identical to Devic's disease (differences between optic-spinal and classic MS in Japanese patients). In the indigenous populations of tropical and subtropical regions, MS is rare, but when it appears, it often takes the form of optic-spinal MS.

The majority of Devic's disease patients have no affected relatives, and it is generally regarded as a nonfamilial condition.

While the exact incidence is unknown, estimates range from 33 - 57 percent of patients staying in the ICU for longer than 7 days. More exact data is difficult to obtain, since variation exists in defining the condition.

The three main risk factors for CIP and CIM are sepsis and systemic inflammatory response syndrome (SIRS), and multi-organ failure. Reported rates of CIP/CIM in people with sepsis and SIRS range from 68 to 100 percent. Additional risk factors for developing CIP/CIM include: female gender, high blood sugar (hyperglycemia), low serum albumin, and immobility. A greater severity of illness increases the risk of CIP/CIM. Such risk factors include: multi-organ dysfunction, renal failure, renal replacement therapy, duration of organ dysfunction, duration of ICU stay, low albumin, and central neurologic failure.

Certain medications are associated with CIP/CIM, such as corticosteroids, neuromuscular blocking agents, vasopressors, catecholamines, and intravenous nutrition (parenteral nutrition). Research has produced inconsistent results for the impact of hypoxia, hypotension, hyperpyrexia, and increased age on the risk of CIP/CIM. The use of aminoglycosides is "not" an independent risk for the development of CIP/CIM.

CNS demyelinating autoimmune diseases are autoimmune diseases which primarily affect the central nervous system.

Examples include:

- Diffuse cerebral sclerosis of Schilder

- Acute disseminated encephalomyelitis

- Acute hemorrhagic leukoencephalitis

- Multiple sclerosis (though the cause is unknown, it is sure that immune system is involved)

- Transverse myelitis

- Neuromyelitis optica

Mononeuropathy is a type of neuropathy that only affects a single nerve. Diagnostically, it is important to distinguish it from polyneuropathy because when a single nerve is affected, it is more likely to be due to localized trauma or infection.

The most common cause of mononeuropathy is physical compression of the nerve, known as compression neuropathy. Carpal tunnel syndrome and axillary nerve palsy are examples. Direct injury to a nerve, interruption of its blood supply resulting in (ischemia), or inflammation also may cause mononeuropathy.

Peripheral neuropathy may be classified according to the number and distribution of nerves affected (mononeuropathy, mononeuritis multiplex, or polyneuropathy), the type of nerve fiber predominantly affected (motor, sensory, autonomic), or the process affecting the nerves; e.g., inflammation (neuritis), compression (compression neuropathy), chemotherapy (chemotherapy-induced peripheral neuropathy).

Polyradiculoneuropathy describes a condition in which polyneuropathy and polyradiculopathy occur together. An example is Guillain–Barré syndrome.

Treatment with a single course of intravenous immunoglobulin (IVIG) infusions has been demonstrated to be a potentially effective treatment (reported to have caused prolonged remission in a case associated with systemic lupus (Systemic lupus erythematosus) ).

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.

Originally found in neuromyelitis optica, this autoantibody has been associated with other conditions. Its current spectrum is as following:

- Seropositive Devic's disease, according to the diagnostic criteria described above

- Limited forms of Devic's disease, such as single or recurrent events of longitudinally extensive myelitis, and bilateral simultaneous or recurrent optic neuritis

- Asian optic-spinal MS - this variant can present brain lesions like MS.

- Longitudinally extensive myelitis or optic neuritis associated with systemic autoimmune disease

- Optic neuritis or myelitis associated with lesions in specific brain areas such as the hypothalamus, periventricular nucleus, and brainstem

- Some cases of tumefactive multiple sclerosis

Though for the most of the cases these diseases are still idiopathic, recent researchs have found the causes for some of them, making them not idiopathic anymore. There are currently two identified auto-antibodies and a genetic variant. The autoantibodies are anti-AQP4 and anti-MOG so far and the genetic variant is a mutation in the gene NR1H3.

CIP/CIM can lead to difficulty weaning a person from a mechanical ventilator, and is associated with increased length of stay in the ICU and increased mortality (death). It can lead to impaired rehabilitation. Since CIP/CIM can lead to decreased mobility (movement), it increases the risk of pneumonia, deep vein thrombosis, and pulmonary embolism.

Critically ill people that are in a coma can become completely paralyzed from CIP/CIM. Improvement usually occurs in weeks to months, as the innervation to the muscles are restored. About half of patients recover fully.

Autoimmune optic neuropathy (AON), sometimes called autoimmune optic neuritis, may be a forme fruste of systemic lupus erythematosus (SLE) associated optic neuropathy. AON is more than the presence of any optic neuritis in a patient with an autoimmune process, as it describes a relatively specific clinical syndrome. AON is characterized by chronically progressive or recurrent vision loss associated with serological evidence of autoimmunity. Specifically, this term has been suggested for cases of optic neuritis with serological evidence of vasculitis by positive ANA, despite the lack of meeting criteria for SLE. The clinical manifestations include progressive vision loss that tends to be steroid-responsive and steroid dependent.

Patients with defined SLE that go on to develop optic neuritis should be better identified as lupus optic neuritis.

Approximately 1-2% of patients with defined SLE develop an optic neuropathy during the course of their disease. SLE-associated optic neuritis is rarely the presenting sign of the disease. The molecular pathogenesis is hypothesized, based on clinical features and the emerging understanding of mechanisms in SLE. Inflammation resulting from auto-antibodies, immune complexes, T-cells and complement, probably damages the components of the optic nerve, as well as the blood vessels (vasculitis). The resulting vasculitis causes a loss of blood supply to the nerve (ischemia). This combination of inflammation and ischemia may produce reversible changes such as demyelination alone, or more permanent damage axonal (necrosis), or a combination. The poor recovery of vision in AON despite anti-inflammatory treatment suggests that ischemia from the underlying vasculitis is an important component, but the details have not been established. It may be reasonable to consider that AON pathogenesis represents an incomplete expression of the SLE-associated optic neuropathy disease process.

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.

Optic neuritis typically affects young adults ranging from 18–45 years of age, with a mean age of 30–35 years. There is a strong female predominance. The annual incidence is approximately 5/100,000, with a prevalence estimated to be 115/100,000.

Hereditary motor and sensory neuropathies are relatively common and are often inherited with other neuromuscular conditions, and these co morbidities cause an accelerated progression of the disease.

Most forms HMSN affects males earlier and more severely than females, but others show no predilection to either sex. HMSN affects all ethnic groups. With the most common forms having no racial prediliections, but other recessively inherited forms tend to impact specific ethnic groups. Onset of HMSN in most common in early childhood, with clinical effects occurring before the age of 10, but some symptoms are lifelong and progress slowly. Therefore, these symptoms do not appear until later in life.

The American College of Rheumatology has outlined 19 syndromes that are seen in NPSLE. These syndromes encompass disorders of the central and peripheral nervous systems:

- Aseptic meningitis

- Cerebrovascular disease

- Demyelinating syndrome

- Headache

- Movement disorder

- Myelopathy

- Seizure disorders

- Acute confusional state

- Anxiety disorder

- Cognitive dysfunction

- Mood disorder

- Psychosis

- Acute inflammatory demyelinating polyradiculoneuropathy

- Autonomic disorder

- Mononeuropathy (single/multiplex)

- Myasthenia gravis

- Cranial neuropathy

- Plexopathy

- Polyneuropathy

Each of the 19 syndromes are also stand-alone diagnoses, which can occur with or without lupus.

The majority of cases involve the central nervous system (CNS), which consists of the brain and spinal cord. The CNS syndromes can be subcategorized as either focal or diffuse. The focal syndromes are neurological, while the diffuse syndromes are psychiatric in nature. The most common CNS syndromes are headache and mood disorder.

Though neuropsychiatric lupus is sometimes referred to as "CNS lupus", it can also affect the peripheral nervous system (PNS). Between 10-15% of people with NPSLE have PNS involvement. Mononeuropathy and polyneuropathy are the most common PNS syndromes.

Acute motor axonal neuropathy (AMAN) is a variant of Guillain–Barré syndrome. It is characterized by acute paralysis and loss of reflexes without sensory loss. Pathologically, there is motor axonal degeneration with antibody-mediated attacks of motor nerves and nodes of Ranvier.

A preceding antigenic challenge can be identified in approximately two-thirds of people. Viral infections thought to induce ADEM include influenza virus, enterovirus, measles, mumps, rubella, varicella zoster, Epstein Barr virus, cytomegalovirus, herpes simplex virus, hepatitis A, and coxsackievirus; while the bacterial infections include Mycoplasma pneumoniae, Borrelia burgdorferi, Leptospira, and beta-hemolytic Streptococci. The only vaccine proven to induce ADEM is the Semple form of the rabies vaccine, but hepatitis B, pertussis, diphtheria, measles, mumps, rubella, pneumococcus, varicella, influenza, Japanese encephalitis, and polio vaccines have all been implicated. The majority of the studies that correlate vaccination with ADEM onset use small samples or case studies. Large scale epidemiological studies (e.g., of MMR vaccine or smallpox vaccine) do not show increased risk of ADEM following vaccination. In rare cases, ADEM seems to follow from organ transplantation. An upper bound for the risk of ADEM from measles vaccination, if it exists, can be estimated to be 10 per million, which is far lower than the risk of developing ADEM from an actual measles infection, which is about 1 per 1,000 cases. For a rubella infection, the risk is 1 per 5,000 cases. Some early vaccines, later shown to have been contaminated with host animal CNS tissue, had ADEM incident rates as high as 1 in 600.