Behçet's disease (BD) is a recurrent, multisystem inflammatory disease that can affect the eyes, skin and mucous membranes, joints, vascular system, lungs, heart, gastrointestinal tract, and nervous system (Akman-Demir, Serdaroglu, Tasci, & Neuro-Behçet Study Group, 1999; Al-Araji, Sharquie, & Al-Rawi, 2003; Tunc et al., 2006). The disease was first described in 1937 by a Turkish dermatologist named Hulusi Behçet (Al-Araji et al., 2003; Tunc et al., 2006). BD is more prevalent in an area extending from the Mediterranean basin to Japan (Al-Araji et al., 2003; Gul, 2005). The prevalence of BD does not differ by gender, but symptomology is often more severe in males (Gul, 2005; Ozdimir, Ozsoylar, Candansayar, Cosar, & Onder, 2004).
When there is neurological involvement in the manifestation of BD, it is sometimes referred to as neuro-BD (Akman-Demir et al., 1999; Al-Araji et al., 2003; Tunc et al., 2006). Neuro-BD has been examined by multiple studies that have resulted in two variants of the disease being identified. The first type is consistently found across the research and presents with parenchymal central nervous system (CNS) involvement. The second type is inconsistent in the research but never has parenchymal CNS involvement (Akman-Demir et al., 1999; Al-Araji et al., 2003; Tunc et al., 2006).
The etiology of BD remains unknown. Although viral, environmental, and autoimmune etiologies have all been alluded to, it has been further specified that these factors are merely relevant in genetically susceptible individuals (Gul, 2005; Kalayclyan & Zouboulis, 2007). Familial cases identified have shown an association between the disease and HLA-B5 and HLA-B1 antigens (Moore & Calabrese, 1994; O’Duffy, 1990) but only in the Middle East and Mediterranean region. This antigen is reportedly present in approximately 84% of BD patients in Turkey; however, it is not found in British or North American patients (Akman-Demir et al., 1999; Ozdimir et al., 2004). Originally theorized as a hypocoagulate state, research has now demonstrated that elevation of procoagulation factors actually represents a secondary feature of BD (Bartt & Topel, 2007).
Pathologically, BD presents as chronic and recurrent vasculitis, primarily affecting small vessels (Ropper & Brown, 2005). The brainstem and diencephalic regions are the most commonly affected on a neurological level (Al-Fahad & Al-Araji, 1999; Kidd, Steuer, Denman, & Rudge, 1999). Spinal cord lesions can also been seen at an intramedullary level, although this is more rare (Kidd et al., 1999). Cerebrospinal fluid (CSF) analysis will commonly show pleocytosis, elevated protein, and normal glucose but is not clinically consistent as negative findings have still been recorded in the literature even in the presence of abnormal MRI (Wechsler et al., 1993).
There are many symptoms associated with BD, particularly genital and oral ulcers as well as uveitis (swelling and irritation of the middle layer of the eye). Vasculitis, or inflammation of the blood vessels, is considered a major feature of the disease (Gul, 2005; Tunc et al., 2006). In addition, ocular symptoms occur in 90% of patients (Miller & Jubelt, 1989). Other features commonly seen in patients with BD include thrombophlebitis (blood clot in a vein deep in the body), oligoarthritis (a type of arthritis), gastrointestinal ulcerations, and neurological involvement (Akman-Demir et al., 1999). Erythema nodosum and polyarteritis are also prevalent (Ropper & Brown, 2005) as are migraines and tension-type headaches (Al-Araji et al., 2003).
The neurological features associated with BD may vary but most commonly include recurrent meningoencephalitis, cranial nerve palsies with abducens involvement being the most common, cerebellar ataxia, and corticospinal tract signs (Ropper & Brown, 2005). Consequently, brainstem involvement due to the aforementioned meningoencephalitis is the most commonly reported location of parenchymal disease (Al-Fahad & Al-Araji, 1999; Kidd et al., 1999). Thrombosis may be seen at higher rates due to the aforementioned vasculitis.
There are no definite diagnostic tests for BD. As a result, the diagnosis is based on the recognition of the clinical features of the disease in combination with ruling out competing diagnostic considerations (Al-Araji et al., 2003). According to the International Study Group for BD, the diagnostic criteria for BD is the presence of recurrent oral ulcers accompanied by any two of the following: genital ulcerations, skin lesions, eye involvement (i.e., anterior and posterior uveitis), or a skin pathergy reaction such as skin hypersensitivity to a nonspecific physical insult (Akman-Demir et al., 1999; Al-Araji et al., 2003).
When neuro-BD is suspected, cranial MRI and magnetic resonance venography are useful for categorizing neurological involvement. Some patients have an asymptomatic presentation, meaning that they do not complain of neurological involvement but have neurological signs. Therefore, a neurological examination should be considered when diagnosing BD (Akman-Demir et al., 1999; Al-Araji et al., 2003). Findings have shown subclinical neurological involvement in patients with BD (Tunc et al., 2006). The main differential diagnosis for neuro-BD is multiple sclerosis. Differential diagnosis may also include other diseases of the CNS including systemic lupus erythematosus, polyarteritis nodosa, bacterial endocarditis, meningitis, encephalitis, and even stroke (Akman-Demir et al., 1999; Al-Araji et al., 2003). Given the potential competing diagnoses, clinical workup may include CSF analysis, metabolic panels, and neuroimaging (Wechsler et al., 1993).
In the past, treatment for BD has included various antibiotics, chemotherapy, and corticosteroids. Immunosuppressive therapy was considered when the neurologic components of the disease were life-threatening (Miller & Jubelt, 1989). Although corticosteroids are still commonly used to address the noted inflammation, they have demonstrated little to no effectiveness in preventing blindness or the morbidity or mortality associated with neuro-BD (Wechsler et al., 1993). The combination of prednisone and alkylating agents can help ward off and treat vessel occlusion. Anticoagulation can also be used in emergent situations but is contraindicated in individuals with pulmonary vasculitis (Bartt & Topel, 2007).
Related Credo Articles
What Is It? Behçet's (bay-setz) syndrome is a rare disease that causes inflammation of many parts of the body. These include the skin of the gen
Definition A group of symptoms that affect a variety of body systems, including musculoskeletal, gastrointestinal, and the central nervous system
DESCRIPTION Behçet's disease (BD) is a recurrent, multisystem inflammatory disease that can affect the eyes, skin and mucous membranes,...