Decreased cerebral blood flow in neuro-Behçet's syndrome patients with neuropsychiatric manifestations and normal magnetic resonance imaging--a preliminary report

Neurological involvement by Behçet's syndrome: clinical features, diagnosis, treatment and outcome

Neurological involvement in Behçet's syndrome arises predominately through an inflammatory meningoencephalitis characterised by perivenular inflammation due to activation of Th-17 immunological pathways. The brainstem is involved in 50% of cases, the diencephalon and other areas of the brain in 30%, and the spinal cord in 10%. Movement disorders and epilepsy may occur. Psychiatric syndromes may arise with brain and brainstem involvement, and cognitive disorders relate to the brain disease, to circulating inflammatory factors, and to fatigue and despondency. Eighty per cent of cases begin with a relapsing disease course, of whom 70% have only one attack, and 30% have a progressive disease course either from onset or following an initially relapsing course. Venous thrombosis leading to intracranial hypertension and cerebral venous infarction is less common and caused by inflammation in affected veins and a circulating prothrombotic state. Arterial involvement is rare and relates to an arteritis affecting large-sized and medium-sized vessels within the brain leading to infarction, subarachnoid and parenchymal haemorrhage, aneurysm formation and arterial dissection. There is a newly recognised disorder of cerebral cortical hypoperfusion. Cranial neuropathy, peripheral neuropathy and myositis are rare. There has been significant progress in understanding the pathophysiology and treatment of the systemic disease, leading to improved outcomes, but there has been no randomised trial of treatment in the neurological disorder.

Width of the third ventricle as a highly-sensitive biomarker in chronic progressive neuro-Behçet's disease

Chronic progressive neuro-Behçet's disease (CPNBD) is characterized by slowly progressive cognitive decline, cerebellar ataxia, and brainstem atrophy without acute encephalomeningitis. To evaluate the progression of CPNBD during treatment, we conducted a retrospective, longitudinal comparative analysis of the clinical features and brain magnetic resonance imaging (MRI) in patients with CPNBD. We classified participants into three groups: NBD with acute encephalomeningitis alone (Group A, 8 patients with acute neuro-Behçet's disease [ANBD]), primary progressive CPNBD (Group B, 3 patients), and a combination of acute encephalomeningitis, and chronic progression (Group C, 2 patients). Routine laboratory tests and monthly rate of enlargement of the width of the third ventricle (ΔWTVm) and relative value of ΔWTVm to the transverse cerebral diameter (ΔWTVIm) were statistically evaluated. Although higher cell count values and interleukin-6 concentration in the cerebrospinal fluid were observed in ANBD, both ΔWTVm (p = 0.008) and ΔWTVIm (p = 0.008) were significantly larger in CPNBD phase than in the ANBD phase. Effective treatment for CPNBD seemed to reduce ΔWTVm and ΔWTVIm in some patients. Sequential evaluation of WTV in patients with CPNBD is a highly sensitive candidate biomarker of early diagnosis and treatment efficacy.

Neuro-Behçet syndrome

Behçet syndrome (BS) is an idiopathic chronic relapsing multisystem vascular-inflammatory disease of unknown origin. As the disease affects many organs and systems and shows a wide range of clinical manifestations and presentations, it is prefereable to call Behçet's a syndrome (BS) rather than a disease. Nervous system involvement, known as "neuro-BS" (NBS), is seen in about 5-10% of all cases. Clinical and imaging evidence suggests that primary neurologic involvement in BS may be subclassified into two major forms: the first, which is seen in the majority of patients, may be characterized as a vascular-inflammatory central nervous system disease with focal or multifocal parenchymal involvement, mostly presenting with a subacute brainstem syndrome and hemiparesis (intra-axial NBS); the other, which has few symptoms and a better neurologic prognosis, may be caused by isolated cerebral venous sinus thrombosis and intracranial hypertension (extra-axial NBS), occurring in 10-20% of the cases. These two types are rarely seen in the same individual, and their pathogenesis is likely to be different. Isolated behavioral syndromes and peripheral nervous system involvement are rare, whereas a vascular type headache is relatively common and independent from neurologic involvement. Neurologic complications secondary to systemic involvement of BS, as well as neurologic complications related to BS treatments are considered as secondary neurologic involvement of the syndrome. The core histopathologic phenomenon seems to be a vasculitic involvement in some cases, and low-grade chronic nonspecific inflammation in others. As the neurologic involvement in this syndrome is so heterogeneous, it is difficult to predict its course and prognosis, and its response to treatment. Currently, treatment options for NBS are limited to attack therapies with high-dose intravenous methylprednisolone followed by a prolonged oral taper, symptomatic management, and generally the use of azathioprine, cyclophosphamide, interferon-α and anti-TNF agents for long-term preventive treatment, although there no evidence for their efficacy.

Brain perfusion MRI findings in patients with Behcet's disease

Objective. To search brain perfusion MRI (pMRI) changes in Behcet's disease (BD) with or without neurological involvement. Materials and Method. The pMRI were performed in 34 patients with BD and 16 healthy controls. Based on neurologic examination and post-contrast MRI, 12 patients were classified as Neuro-Behcet (group 1, NBD) and 22 patients as BD without neurological involvement (group 2). Mean transit time (MTT), time to peak (TTP), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) were obtained and compared to those of healthy control group (group 3). Results. There was a significant difference in the MTT and rCBF within the pons and parietal cortex in groups 1 and 2. rCBV increased in cerebral pedicle in group 1 compared with groups 2 and 3. In the temporal lobe white matter, prolonged MTT and decreased rCBF were found in groups 1 and 2. In the corpus striatum, internal capsule, and periventricular white matter, rCBF increased in group 1 compared with group 3 and decreased in groups 1 and 2. Conclusion. Brain pMRI is a very sensitive method to detect brain involvement in patients with BD and aids the clinical diagnosis of NBD, especially in patients with negative MRI findings.

The spectrum of nervous system involvement in Behçet's syndrome and its differential diagnosis

Behçet's Syndrome (BS) is a multi-system, vascular-inflammatory disease of unknown origin, involving the nervous system in a subgroup of patients. The growing clinical and imaging evidence suggests that primary neurological involvement in BS may be subclassified into two major forms: the first one, which is seen in the majority of patients, may be characterized as a vascular-inflammatory central nervous system (CNS) disease, with focal or multifocal parenchymal involvement mostly presenting with a subacute brainstem syndrome and hemiparesis; the other, which has few symptoms and a better neurological prognosis, may be caused by isolated cerebral venous sinus thrombosis and intracranial hypertension. These two types rarely occur in the same individual, and their pathogenesis is likely to be different. Isolated behavioral syndromes and peripheral nervous system involvement are rare, whereas a nonstructural vascular type headache is relatively common and independent from neurological involvement. Neurologic complications secondary to systemic involvement of BS such as cerebral emboli from cardiac complications of BS and increased intracranial pressure due to superior vena cava syndrome, as well as neurologic complications related to BS treatments such as CNS neurotoxicity with cyclosporine and peripheral neuropathy with the use of thalidomide or colchisin are considered as secondary neurological complications of this syndrome. As the neurological involvement in this syndrome is so heterogeneous, it is difficult to predict its course and prognosis, and response to treatment. Currently, treatment options are limited to attack and symptomatic therapies with no evidence for the efficacy of any long term preventive treatment.

Epileptic seizures as the sole manifestation of neuro-Behçet's disease: complete control under interferon-alpha treatment

Behçet's disease (BD) is a multisystemic disease of unknown etiopathogenesis with various clinical features including manifestations from central nervous system involvement. We report the case of a patient presented with a 20-year history of BD and a 10-year history of epileptic seizures refractory to various antiepileptic drugs. Under systemic treatment with interferon-alpha 2a (IFN-alpha) a complete remission of the cutaneous manifestations and a seizure-free state were achieved. The impressive therapeutic response of both the seizures and the non-neurological manifestations to IFN-alpha was also observed upon re-administration of this cytokine subsequent to a severe BD relapse. In view of this response and the lack of any other obvious etiology of the seizures in our patient, it seems reasonable to consider them as being the sole manifestation of neuro-BD. The patient is presently completing a 40-month seizure-free follow-up, despite withdrawal of all antiepileptic drugs for the last 35 months. Further studies on large numbers of patients are now warranted to define the therapeutic efficacy and safety of IFN-alpha in neuro-BD and particularly in neuro-BD-related epileptic seizures.

Neurological involvement in North Italian patients with Behçet disease

The aim of this study was to evaluate neurological involvement in a series of 110 North Italian patients with Behçet disease (BD), a multisystemic vasculitis of unknown origin, followed up for a period of 5 years. During this time, 27 (24.5%) patients with neuro-BD were identified. Twenty out of 27 showed at least one acute attack in their clinical course. In 14 of them, a neurological evaluation was carried out during the attack. The other 13 patients were evaluated during a remission phase. The onset of neuro-BD was usually characterized by an acute attack with motor symptoms (66.6%) and behavioural/cognitive changes (47.6%), while headache was more frequent in the remission phase (76.9%). On magnetic resonance imaging, large brain-stem/diencephalon lesions were usually seen during the attack. In the remission phase, they were often located in the white-matter. Aspecific cerebrospinal fluid abnormalities were usually seen during the attacks. Cerebrospinal fluid analysis together with radiological and clinical features seems to be useful for the differential diagnosis in these patients.

Beh??et??s syndrome and the nervous system

PURPOSE OF REVIEW

Behçet's syndrome (BS) is a multi-system, vascular-inflammatory disease of unknown origin, involving the nervous system in a subgroup of patients. The syndrome is rare, but as patients with BS are young and frequently present with an acute or subacute brainstem syndrome or hemiparesis, as well as with other various neurological manifestations, the syndrome is often included in the differential diagnosis of multiple sclerosis, stroke of the young adult, and another wide range of neurological disorders. The present review summarizes the neurological involvement in BS, and emphasizes recent clinical concepts and ethiopathogenetic findings.

RECENT FINDINGS

Over the last years the growing clinical and imaging evidence had suggested that neurological involvement in BS may be subclassified into two major forms: one, which is seen in the majority of patients, may be characterized as a vascular-inflammatory CNS disease, with focal or multifocal parenchymal involvement; the other, which has few symptoms and a better neurological prognosis, may be caused by isolated cerebral venous sinus thrombosis and intracranial hypertension. These two types rarely occur in the same individual, and their pathogenesis is likely to be different. A nonstructural vascular type headache is relatively common, whereas isolated behavioral syndromes and peripheral nervous system involvement are rare.

SUMMARY

The involvement of the nervous system in BS is heterogeneous as clinical and imaging data reveal. Currently it is unknown which factors determine or have a role in the development of neurological involvement, but some progress has been achieved in understanding the neurological spectrum of the syndrome, which may lead to a better management of these patients.