"Primary" Central Nervous System (CNS) vasculitis is said to be present if there is no underlying cause. The exact mechanism of the primary disease is unknown, but the fundamental mechanism of all vasculitides is auto-immune. Other possible causes of cerebral vasculitis are infections, systemic auto-immune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis, medications and drugs (amphetamine, cocaine and heroin), some forms of cancer (lymphomas, leukemia and lung cancer) and other forms of systemic vasculitis such as granulomatosis with polyangiitis, polyarteritis nodosa or Behçet's disease. It may imitate, and is in turn imitated by, a number of other diseases that affect the blood vessels of the brain diffusely such as fibromuscular dysplasia and thrombotic thrombocytopenic purpura.

Treatment is first with many different high-dose steroids, namely glucocorticoids. Then, if symptoms do not improve additional immunosuppression such as cyclophosphamide are added to decrease the immune system's attack on the body's own tissues. Cerebral vasculitis is a very rare condition that is difficult to diagnose, and as a result there are significant variations in the way it is diagnosed and treated.

The condition affects adults more frequently than children and males more frequently than females. Most cases occur between the ages of 30 and 49. It damages the tissues supplied by the affected arteries because they do not receive enough oxygen and nourishment without a proper blood supply. Polyarteritis nodosa is more common in people with hepatitis B infection.

Treatment involves medications to suppress the immune system, including prednisone and cyclophosphamide. In some cases, methotrexate or leflunomide may be helpful. Some patients have also noticed a remission phase when a four-dose infusion of rituximab is used before the leflunomide treatment is begun. Therapy results in remissions or cures in 90% of cases. Untreated, the disease is fatal in most cases. The most serious associated conditions generally involve the kidneys and gastrointestinal tract. A fatal course usually involves gastrointestinal bleeding, infection, myocardial infarction, and/or kidney failure.

In case of remission, about 60% experience relapse within five years. In cases caused by hepatitis B virus, however, recurrence rate is only around 6%.

Vasculitis is a group of disorders that destroy blood vessels by inflammation. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis. Vasculitis is primarily caused by leukocyte migration and resultant damage.

Although both occur in vasculitis, inflammation of veins (phlebitis) or arteries (arteritis) are their own are separate entities.

With Behçet's disease as an intercurrent disease in pregnancy, the pregnancy does not have an adverse effect on the course of Behçet's disease and may possibly ameliorate its course. Still, there is a substantial variability in clinical course between patients and even for different pregnancies in the same patient. Also, the other way around, Behçet's disease confers an increased risk of pregnancy complications, miscarriage and Cesarean section.

Behçet's can cause male infertility, either as a result of the condition itself or of a side effect of concomitant medication such as Colchicine, which is known to lower sperm count.

Lupus systemic erythematosus is one of the most common causes of cerebritis as it is believed that more than half of the patients with lupus from the United States suffer from a degree or another of lupus cerebritis.

The exact pathophysiological process of lupus cerebritis is unknown. The proposed mechanisms are likely due to the assault of several autoimmune system changes, including the following:

- Circulating immune complexes. The immune complexes, which consist of DNA and anti-DNA, cause an inflammatory response as well as a disruption of the blood–brain barrier. These circulating complexes have been found trapped in the highly vascular choroid plexus of SLE patients upon autopsy. True vasculitis, however, is found only in about 10% of patients with cerebral lupus.

- Anti-neuronal antibodies. The three identified anti-neuronal antibodies postulated in CNS involvement are the lympho-cytotoxic antibodies (LCAs), which somehow react with brain tissue and interfere with the neuron's ability to respond. LCAs have a specific role and are found in both the serum and cerebrospinal fluid (CSF) of lupus patients with cerebritis. These antibodies also correlate with cognitive and visual spatial defects. Second, the anti-neuronal membrane antibodies are targeted directly to neuronal antigens. They, too, are found in the serum of SLE patients with cerebritis. And third, the intracytoplasmic antibodies target the constituents of the neuron cells and they are found in the CSF and serum. These antibodies are seen in 90% of SLE patients with psychosis.

- Antiphospholipid antibodies. The two antibodies implicated are anticardiolipin and lupus anticoagulant. Anticardiolipin antibodies attach to the endothelial lining of cells, causing endothelial damage, platelet aggregation, inflammation, and fibrosis.

- Cytokine release. The final mechanism of lupus cerebritis involves the cytokines. The cytokines trigger edema, endothelial thickening, and infiltration of neutrophils in brain tissue. Two cytokines, interferon alpha and interleukin-6, have been found in the CSF of SLE patients with psychosis.

However, it is not clear which mechanism is the actual cause of cerebritis in lupus patients. Specialists believe that all mechanisms may be present at the same time or they may act independently.

In very rare cases, cerebritis may occur as a result of a Klebsiella pneumoniae infection.

One other reason to develop cerebritis is an infection caused by bacteria, viruses, or other organisms. Infections can occur when infectious agents enter the brain through the sinuses or as a result of trauma. Some pathogens are also capable of passing over the blood–brain barrier and entering the brain through the bloodstream, despite the fact that the body has evolved defenses which are specifically designed to prevent this.

Autosomal Dominant Retinal Vasculopathy with Cerebral Leukodystrophy (AD-RVCL) (previously known also as Cerebroretinal Vasculopathy, CRV, or Hereditary Vascular Retinopathy, HVR or Hereditary Endotheliopathy, Retinopathy, Nephropathy, and Stroke, HERNS) is an inherited condition resulting from a frameshift mutation to the TREX1 gene. This genetically inherited condition affects the retina and the white matter of the central nervous system, resulting in vision loss, lacunar strokes and ultimately dementia. Symptoms commonly begin in the early to mid-forties, and treatments currently aim to manage or alleviate the symptoms rather than treating the underlying cause. The overall prognosis is poor, and death can sometimes occur within 10 years of the first symptoms appearing.

AD-RVCL (CRV) Acronym

Autosomal Dominance (genetics) means only one copy of the gene is necessary for the symptoms to manifest themselves.

Retinal Vasculopathy means a disorder that is associated with a disease of the blood vessels in the retina.

Cerebral means having to do with the brain.

Leukodystrophy means a degeneration of the white matter of the brain.

Pathogenesis

The main pathologic process centers on small blood vessels that prematurely “drop out” and disappear. The retina of the eye and white matter of the brain are the most sensitive to this pathologic process. Over a five to ten-year period, this vasculopathy (blood vessel pathology) results in vision loss and destructive brain lesions with neurologic deficits and death.

Most recently, AD-RVCL (CRV) has been renamed. The new name is CHARIOT which stands for Cerebral Hereditary Angiopathy with vascular Retinopathy and Impaired Organ function caused by TREX1 mutations.

Treatment

Currently, there is no therapy to prevent the blood vessel deterioration.

About TREX1

The official name of the TREX1 gene is “three prime repair exonuclease 1.” The normal function of the TREX1 gene is to provide instructions for making the 3-prime repair exonuclease 1 enzyme. This enzyme is a DNA exonuclease, which means it trims molecules of DNA by removing DNA building blocks (nucleotides) from the ends of the molecules. In this way, it breaks down unneeded DNA molecules or fragments that may be generated during genetic material in preparation for cell division, DNA repair, cell death, and other processes.

Changes (mutations) to the TREX1 gene can result in a range of conditions one of which is AD-RVCL. The mutations to the TREX1 gene are believed to prevent the production of the 3-prime repair exonuclease 1 enzyme. Researchers suggest that the absence of this enzyme may result in an accumulation of unneeded DNA and RNA in cells. These DNA and RNA molecules may be mistaken by cells for those of viral invaders, triggering immune system reactions that result in the symptoms of AD-RVCL.

Mutations in the TREX1 gene have also been identified in people with other disorders involving the immune system. These disorders include a chronic inflammatory disease called systemic lupus erythematosus (SLE), including a rare form of SLE called chilblain lupus that mainly affects the skin.

The TREX1 gene is located on chromosome 3: base pairs 48,465,519 to 48,467,644

The immune system.

- The immune system is composed of white blood cells or leukocytes.

- There are 5 different types of leukocytes.

- Combined, the 5 different leukocytes represent the 2 types of immune systems (The general or innate immune system and the adaptive or acquired immune system).

- The adaptive immune system is composed of two types of cells (B-cells which release antibodies and T-cells which destroy abnormal and cancerous cells).

How the immune system becomes part of the condition.

During mitosis, tiny fragments of “scrap” single strand DNA naturally occur inside the cell. Enzymes find and destroy the “scrap” DNA. The TREX1 gene provides the information necessary to create the enzyme that destroys this single strand “scrap” DNA. A mutation in the TREX1 gene causes the enzyme that would destroy the single strand DNA to be less than completely effective. The less than completely effective nature of the enzyme allows “scrap” single strand DNA to build up in the cell. The buildup of “scrap” single strand DNA alerts the immune system that the cell is abnormal.

The abnormality of the cells with the high concentration of “scrap” DNA triggers a T-cell response and the abnormal cells are destroyed. Because the TREX1 gene is identical in all of the cells in the body the ineffective enzyme allows the accumulation of “scrap” single strand DNA in all of the cells in the body. Eventually, the immune system has destroyed enough of the cells in the walls of the blood vessels that the capillaries burst open. The capillary bursting happens throughout the body but is most recognizable when it happens in the eyes and brain because these are the two places where capillary bursting has the most pronounced effect.

Characteristics of AD-RVCL

- No recognizable symptoms until after age 40.

- No environmental toxins have been found to be attributable to the condition.

- The condition is primarily localized to the brain and eyes.

- Optically correctable, but continuous, deterioration of visual acuity due to extensive multifocal microvascular abnormalities and retinal neovascularization leading, ultimately, to a loss of vision.

- Elevated levels of alkaline phosphatase.

- Subtle vascular changes in the retina resembling telangiectasia (spider veins) in the parafovea circulation.

- Bilateral capillary occlusions involving the perifovea vessels as well as other isolated foci of occlusion in the posterior pole of the retina.

- Headaches due to papilledema.

- Mental confusion, loss of cognitive function, loss of memory, slowing of speech and hemiparesis due to “firm masses” and white, granular, firm lesions in the brain.

- Jacksonian seizures and grand mal seizure disorder.

- Progressive neurologic deterioration unresponsive to systemic corticosteroid therapy.

- Discrete, often confluent, foci of coagulation necrosis in the cerebral white matter with intermittent findings of fine calcium deposition within the necrotic foci.

- Vasculopathic changes involving both arteries and veins of medium and small caliber present in the cerebral white matter.

- Fibroid necrosis of vessel walls with extravasation of fibrinoid material into adjacent parenchyma present in both necrotic and non-necrotic tissue.

- Obliterative fibrosis in all the layers of many vessel walls.

- Parivascular, adventitial fibrosis with limited intimal thickening.

Conditions with similar symptoms that AD-RVCL can be misdiagnosed as:

- Brain tumors

- Diabetes

- Macular degeneration

- Telangiectasia (Spider veins)

- Hemiparesis (Stroke)

- Glaucoma

- Hypertension (high blood pressure)

- Systemic Lupus Erythematosus (SLE (same original pathogenic gene, but definitely a different disease because of a different mutation in TREX1))

- Polyarteritis nodosa

- Granulomatosis with polyangiitis

- Behçet's disease

- Lymphomatoid granulomatosis

- Vasculitis

Clinical Associations

- Raynaud's phenomenon

- Anemia

- Hypertension

- Normocytic anemia

- Normochromic anemia

- Gastrointestinal bleeding or telangiectasias

- Elevated alkaline phosphatase

Definitions

- Coagulation necrosis

- Endothelium

- Fibrinoid

- Fibrinoid necrosis

- Frameshift mutation

- Hemiparesis

- Jacksonian seizure

- Necrotic

- Necrosis

- Papilledema

- Perivascular

- Retinopathy

- Telangiectasia

- Vasculopathy

- Vascular

What AD-RVCL is not:

- Infection

- Cancer

- Diabetes

- Glaucoma

- Hypertension

- A neurological disorder

- Muscular dystrophy

- Systemic Lupus Erythematosis (SLE)

- Vasculitis

Things that have been tried but turned out to be ineffective or even make things worse:

- Antibiotics

- Steroids

- X-Ray therapy

- Immunosuppression

History of AD-RVCL (CRV)

- 1985 – 1988: CRV (Cerebral Retinal Vasculopathy) was discovered by John P. Atkinson, MD at Washington University School of Medicine in St. Louis, MO

- 1988: 10 families worldwide were identified as having CRV

- 1991: Related disease reported, HERNS (Hereditary Endiotheliopathy with Retinopathy, Nephropathy and Stroke – UCLA

- 1998: Related disease reported, HRV (Hereditary Retinal Vasculopathy) – Leiden University, Netherlands

- 2001: Localized to Chromosome 3.

- 2007: The specific genetic defect in all of these families was discovered in a single gene called TREX1

- 2008: Name changed to AD-RVCL Autosomal Dominant-Retinal Vasculopathy with Cerebral Leukodystrophy

- 2009: Testing for the disease available to persons 21 and older

- 2011: 20 families worldwide were identified as having CRV

- 2012: Obtained mouse models for further research and to test therapeutic agents

Lupus is a condition with no known cure. Lupus cerebritis however is treated by suppressing the autoimmune activity.

When it is caused by infections, treatment consists of medication that will primarily cure the infection. For inflammation, steroids can be used to bring down the swelling. If the swelling appears to have increased to a dangerous level, surgery may be needed to relieve pressure on the brain. The formation of an abscess also calls for surgery as it will be necessary to drain the abscess.

Possible symptoms include:

- General symptoms: Fever, weight loss

- Skin: Palpable purpura, livedo reticularis

- Muscles and joints: Myalgia or myositis, arthralgia or arthritis

- Nervous system: Mononeuritis multiplex, headache, stroke, tinnitus, reduced visual acuity, acute visual loss

- Heart and arteries: Myocardial infarction, hypertension, gangrene

- Respiratory tract: Nose bleeds, bloody cough, lung infiltrates

- GI tract: Abdominal pain, bloody stool, perforations

- Kidneys: Glomerulonephritis

The syndrome is rare in the United States, Africa and South America, but is common in the Middle East and Asia, suggesting a possible cause endemic to those tropical areas. A theory suggested that past exposure to lethal infectious agents might have fixed the genetic susceptibility factors to Behçet's disease in those area. It is not associated with cancer, and links with tissue-types (which are under investigation) are not certain. It also does not follow the usual pattern for autoimmune diseases. However, one study has revealed a possible connection to food allergies, particularly to dairy products. An estimated 15,000 to 20,000 Americans have been diagnosed with this disease. In the UK, it is estimated to have about 1 case for every 100,000 people. Globally, males are affected more frequently than females. In the United States, more females are affected than males.

In an epidemiologic study, 56 percent of patients with Behçet's disease developed ocular involvement at a mean age of 30. Ocular involvement was the first manifestation of Behçet's disease in 8.6 percent of patients. Ocular Behçet's disease with involvement of the optic nerve is rarely reported. Among patients with ocular Behçet's disease funduscopic findings of optic atrophy, and optic disc paleness have been identified with a frequency of 17.9 percent and 7.4 percent, respectively. Other fundoscopic findings include vascular sheathing (23.7%), retinal hemorrhage (9%), macular edema (11.3%), branch retinal vein occlusion (5.8%), and retinal edema (6.6%). However, optic atrophy was the most significant cause of visual impairment identified in 54 percent of patients with ocular Behçet's disease and permanent visual impairment.

The prevalence of this disease increases from North to South. It follows a more severe course in patients with an early age of onset particularly in patients with eye and gastrointestinal involvement.

Overall prognosis is good in most patients, with one study showing recovery occurring in 94% and 89% of children and adults, respectively (some having needed treatment). In children under ten, the condition recurs in about a third of all cases and usually within the first four months after the initial attack. Recurrence is more common in older children and adults.

It is relatively unusual (25% of the total number of cases) for cholesterol emboli to occur spontaneously; this usually happens in people with severe atherosclerosis of the large arteries such as the aorta. In the other 75% it is a complication of medical procedures involving the blood vessels, such as vascular surgery or angiography. In coronary catheterization, for instance, the incidence is 1.4%. Furthermore, cholesterol embolism may develop after the commencement of anticoagulants or thrombolytic medication that decrease blood clotting or dissolve blood clots, respectively. They probably lead to cholesterol emboli by removing blood clots that cover up a damaged atherosclerotic plaque; cholesterol-rich debris can then enter the bloodsteam.

Kawasaki disease affects boys more than girls, with people of Asian ethnicity, particularly Japanese and Korean people, most susceptible, as well as people of Afro-Caribbean ethnicity. The disease was rare in Caucasians until the last few decades, and incidence rates fluctuate from country to country.

Currently, Kawasaki disease is the most commonly diagnosed pediatric vasculitis in the world. By far, the highest incidence of Kawasaki disease occurs in Japan, with the most recent study placing the attack rate at 218.6 per 100,000 children <5 years of age (about one in 450 children). At this present attack rate, more than one in 150 children in Japan will develop Kawasaki disease during their lifetimes.

However, its incidence in the United States is increasing. Kawasaki disease is predominantly a disease of young children, with 80% of patients younger than five years of age. About 2,000-4,000 cases are identified in the U.S. each year (9 to 19 per 100,000 children younger than 5 years of age).

In the United Kingdom, estimates of incidence rate vary because of the rarity of Kawasaki disease. However, it is believed to affect fewer than one in every 25,000 people. Incidence of the disease doubled from 1991 to 2000, however, with four cases per 100,000 children in 1991 compared with a rise of eight cases per 100,000 in 2000.

In the continental United States, Kawasaki Disease is more common during the winter and early spring, boys with the disease outnumber girls by ≈1.5–1.7:1, and 76% of affected children are <5 years of age.

HSP occurs more often in children than in adults, and usually follows an upper respiratory tract infection. Half of affected patients are below the age of six, and 90% are under ten. It occurs about twice as often in boys as in girls. The incidence of HSP in children is about 20 per 100,000 children per year, making it the most common vasculitis in children.

Cases of HSP may occur anytime throughout the year, but some studies have found that fewer cases occur during the summer months.

Many individuals have mild symptoms, which recur infrequently, while others may have persistent problems that become debilitating or life-threatening.

The papules characteristic for this disease develop due to infractions, or blockages in small-medium arteries and veins. The underlying cause is unknown for this disease. Though not confirmed, some cases have shown signs of inheritance between first-degree relatives. It has been suggested that the disease has a familial inheritance pattern; it is thought to be an autosomal dominant disorder. In most cases of familial inheritance, the benign variant of the disease has been present.

Due to the lack of knowledge of the pathomechanism for this condition prevention strategies are not known. However, in order to prevent worsening of symptoms, consistent evaluations should be conducted by a physician.

Relapsing polychondritis is an autoimmune disease in which the body's immune system begins to attack and destroy the cartilage tissues in the body. It has been postulated that both cell-mediated immunity and humoral immunity are responsible.

Reasons for disease onset are not known, but there is no evidence of a genetic predisposition to developing relapsing polychondritis. However, there are cases where multiple members of the same family have been diagnosed with this illness. Studies indicate that some genetic contribution to susceptibility is likely.

As the cause(s) of Kawasaki disease remain unknown, the illness is more accurately referred to as Kawasaki syndrome. Its cause is widely hypothesized to involve the interaction of genetic and environmental factors, possibly including an infection in combination with genetic predisposition to an autoimmune mechanism. The specific cause is unknown, but current theories center primarily on immunological causes. Evidence increasingly points to an infectious cause, but debate continues on whether the cause is a conventional antigenic substance or a superantigen. Researchers at Boston Children's Hospital reported, "some studies have found associations between the occurrence of Kawasaki disease and recent exposure to carpet cleaning or residence near a body of stagnant water; however, cause and effect have not been established."

Other data show a clear correlation between Kawasaki disease and tropospheric wind patterns; winds blowing from central Asia correlate with Kawasaki disease cases in Japan, Hawaii, and San Diego. This association with tropospheric winds has been shown to be modulated at seasonal and interannual timescales by the El Niño–Southern Oscillation phenomenon, further indicating the agent responsible for the disease is a wind-borne pathogen. Efforts are underway to identify the suspected pathogen in air-filters flown at altitude above Japan.

An association has been identified with an SNP in the "ITPKC" gene, which codes an enzyme that negatively regulates T-cell activation. Regardless of where they are living, Japanese children are more likely than other children to manifest the disease, which suggests genetic susceptibility. The HLA-B51 serotype has been found to be associated with endemic instances of the disease.

Nervous system disease refers to a small class of medical conditions affecting the nervous system.

The Nervous System Diseases can be divided into two categories:

- Central nervous system disease in the CNS

- Peripheral neuropathy in the PNS

Although this disease has been known for around 70 years, the pathomechanism underlying it is still unknown. Several hypotheses have been developed regarding the underlying mechanism for Degos disease. One theory suggests that inflammation of blood vessels may trigger development of the condition. Another theory has to do with Degos disease as a coagulopathy. Development of a thrombus and resulting reduction of blood flow is common in this condition. A reduction in blood flow throughout the body can lead to damaged endothelial cells and may perhaps lead to the formation of the characteristic papules. Another hypothesis suggests that abnormal swelling and proliferation of the vascular endothelium can lead to intestinal and central nervous system thrombosis, and ultimately lead to development of symptoms associated with Degos disease. Overall, individuals with Degos disease have abnormal blockages in their arteries and veins; however, the cause of these blockages is unknown.

Cholesterol embolism (often cholesterol crystal embolism or atheroembolism, sometimes blue toe or purple toe syndrome or trash foot or warfarin blue toe syndrome) occurs when cholesterol is released, usually from an atherosclerotic plaque, and travels as an embolus in the bloodstream to lodge (as an embolism) causing an obstruction in blood vessels further away. Most commonly this causes skin symptoms (usually livedo reticularis), gangrene of the extremities and sometimes renal failure; problems with other organs may arise, depending on the site at which the cholesterol crystals enter the bloodstream. When the kidneys are involved, the disease is referred to as atheroembolic renal disease (AERD). The diagnosis usually involves biopsy (removing a tissue sample) from an affected organ. Cholesterol embolism is treated by removing the cause and giving supportive therapy; statin drugs have been found to improve the prognosis.

The third and final stage, and hallmark of EGPA, is inflammation of the blood vessels, and the consequent reduction of blood flow to various organs and tissues. Local and systemic symptoms become more widespread and are compounded by new symptoms from the vasculitis.

Severe complications may arise. Blood clots may develop within the damaged arteries in severe cases, particularly in arteries of the abdominal region, which is followed by infarction and cell death, or slow atrophy. Many patients experience severe abdominal complaints; these are most often due to peritonitis and/or ulcerations and perforations of the gastrointestinal tract, but occasionally due to acalculous cholecystitis or granulomatous appendicitis.

The most serious complication of the vasculitic stage is heart disease, which is the cause of nearly one-half of all deaths in patients with EGPA. Among heart disease-related deaths, the most usual cause is inflammation of the heart muscle caused by the high level of eosinophils, although some are deaths due to inflammation of the arteries that supply blood to the heart or pericardial tamponade. Kidney complications have been reported as being less common.

Cutaneous vasculitis can have various causes including but not limited to medications, bacterial and viral infections or allergens. It is estimated that 45-55% of cases are idiopathic, meaning the cause is unknown. In cases where a cause can be determined, medications and infectious pathogens are most common in adults, while IgA vasculitis (Henoch-Schönlein purpura) frequently affects children. Other etiologies include autoimmune conditions and malignancies, usually hematologic (related to the blood).

The small vessels in the skin affected are located in the superficial dermis and include arterioles (small arteries carrying blood to capillaries), capillaries, and venules (small veins receiving blood from capillaries). In general, immune complexes deposit in vessel walls leading to activation of the complement system. C3a and C5a, proteins produced from the complement system, attract neutrophils to the vessels. Once activated, neutrophils then release preformed substances, including enzymes causing damage to vessel tissue. Evidence of this process can be seen with a sample of removed skin tissue, or biopsy, viewed under a microscope. Neutrophils are seen surrounding blood vessels and their debris within vessel walls, causing fibrinoid necrosis. This finding on histological examination is termed “leukocytoclastic vasculitis”.

Considering the wide range of potential causes leading to cutaneous small vessel vasculitis, there are subtle variations in the underlying pathophysiology for each cause. For example, medications are metabolized to smaller molecules that can attach to proteins in the blood or vessel walls. The immune system senses these altered proteins as foreign and produces antibodies in efforts to eliminate them from the body. A similar process occurs with infectious agents, such as bacteria, in which antibodies target microbial components.

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.