Neuro-Behçet's disease: analysis of apparent diffusion coefficients

Apparent diffusion coefficient characteristics of parenchymal neuro-Behçet's disease

AIM

To evaluate apparent diffusion coefficient (ADC) characteristic of parenchymal neuro-Behçet's disease (NBD).

METHODS

We retrospectively reviewed cranial magnetic resonance imaging (MRI) examinations of NBD patients with acute or chronic parenchymal lesions. ADC measurements of the lesions and contralateral normal brain parenchyma were performed by a consensus of two radiologists. To compare the ADC value of the chronic and acute lesions, relative ADC values (rADC) were calculated. The ratio of the lesions' ADC to contralateral normal brain parenchyma ADC yielded a rADC value of the lesions. Contrast enhancement patterns and the locations of the lesions were also noted.

RESULTS

A total of 24 NBD patients with 45 parenchymal lesions, 25 acute, and 20 chronic, were enrolled in the study. A significant difference was observed between the mean ADC value of the acute lesions (1074.48 ± 138.31 m/s) and the mean ADC value of the contralateral normal brain parenchyma (841.20 ± 142.96 m/s; P < 0.0001). A significant difference was observed between the mean ADC value of the chronic lesions (1069.95 ± 143.95 m/s) and the mean ADC value of the contralateral normal brain parenchyma (793.90 ± 96.71 m/s; P < 0.0001). No significant difference was observed between the mean rADC (1.35 ± 0.20) and the mean rADC value of the chronic lesions (1.29 ± 0.15; P = 0.22).

CONCLUSIONS

ADC measurements might provide substantial information about the histopathological aspect of parenchymal NBD lesions.

Cerebral Small-Vessel Disease in Neuro-Behçet Disease

BACKGROUND

Involvement of central nervous system is very common in Behçet disease, known as neuro-Behçet disease (NBD). However, there have been few reports which evaluated stroke-like cerebral small-vessel disease associated with Behçet disease.

OBJECTIVE

We evaluated cerebral small-vessel lesions by using magnetic resonance imaging in 2 patients with NBD.

CLINICAL CASES

In a 41-year-old woman case, who developed dysarthria and left hemiparesis, diffusion-weighted images (DWI) showed small high-intensity areas in the bilateral internal capsule. The right lesion had a low apparent diffusion coefficient (ADC) value, whereas the left one had a high value. In a 59-year-old woman case, who developed dysarthria and left hemihypesthesia, DWI showed high-intensity areas in the right side of the pons and in the right peduncle of the midbrain. The lesion in the pons had a low ADC value, whereas the lesion in the midbrain had a high value. ADC map may be useful to identify symptomatic lesions in the brain, because only the lesions with low ADC values were symptomatic.

CONCLUSIONS

NBD should be considered in those who had not had any risk factors for ischemic stroke but experienced cerebral small-vessel disease.

Quantitative analysis of brainstem atrophy on magnetic resonance imaging in chronic progressive neuro-Behçet's disease

OBJECTIVES

To examine whether quantitative analysis of the brainstem areas on magnetic resonance imaging (MRI) scans is useful for diagnosis as well as evaluation of disease activity in chronic progressive neuro-Behçet's disease (CPNB).

METHODS

MRI scans in patients with acute neuro-Behçet's disease (ANB) (n = 10), CPNB (n = 10), Behçet's disease with neurological manifestations non-attributable to NB (non-NB) (n = 8), and control patients with non-inflammatory neurological diseases (NID) (n = 10) were studied. The areas of midbrain tegmentum and pons were measured on mid-sagittal sections of T1-weighted images of MRI using software NIH Image J ver.1.45.

RESULTS

The areas of midbrain tegmentum as well as those of pons were significantly decreased in CPNB compared with those in the other three groups. On receiver operating characteristic (ROC) analysis, the sensitivity and specificity of the areas of brainstem combining midbrain tegmentum and pons for diagnosis of CPNB against non-CPNB (ANB+non-NB) were 80.0% and 94.4%, respectively, at cut-off value of 614.9 mm(2). Brainstem atrophy progressed most markedly during the first 2 years during the course of CPNB. Moreover, the progression rate of atrophy was closely correlated with the elevation of cerebrospinal fluid interleukin-6.

CONCLUSION

These results indicate that quantitative analysis of the brainstem areas on MRI scans is effective for diagnosis as well as for evaluation of the disease activity in CPNB. Moreover, it is suggested that an appropriate therapeutic intervention to reduce CSF IL-6 would be required as early as possible upon diagnosis of CPNB.

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.

Clinicopathologic features and outcomes of neuro-Behçet disease in Spain: a study of 20 patients

BACKGROUND

To describe the clinical characteristics and evolution of a series of adult patients hospitalized for neuro-Behçet disease (NBD).

METHODS

Consecutive patients admitted for NBD in a teaching hospital were retrospectively selected. Disability at discharge and during follow-up was graded with the modified Rankin Scale, and outcome classified as good or poor (grades 3-6).

RESULTS

Twenty patients were included (M/F, 13/7). Mean age at NBD diagnosis was 36.3 years. Nineteen patients had other manifestations of Behçet disease (BD) before NBD developed, but only 7 met the complete diagnostic criteria for BD. Fever, headache, motor weakness, and cranial nerve palsy were each present in approximately 60% of patients. There was a low prevalence of behavioral changes (5%), seizures (5%), and sphincter incontinence (0%), and a relatively high prevalence of meningism (25%). Non-neurologic manifestations of BD were concurrently detected in 15 patients (75%). 80% had parenchymal involvement. Brain biopsies during 5 attacks showed perivascular lymphocytic infiltration with reactive astrocytosis, but no frank vasculitis. During a mean follow-up of 6.3 years per patient, 12 had at least one relapse. In total, there were 22 relapses; all but two were in the same location and were symptomatically similar in each patient. At the end of follow-up, 7 patients (35%) had a poor outcome, including 4 who died.

CONCLUSION

Recording of previous manifestations of BD and a physical examination to detect concomitant systemic manifestations of BD may help establish an early diagnosis of NBD. Relapses frequently occurred in the same location. No frank vasculitis was present in brain biopsies.

Primary angiitis of the central nervous system: apparent diffusion coefficient lesion analysis

Apparent diffusion coefficients (ADCs) of the brain lesions in primary angiitis of the central nervous system (PACNS) patients were analyzed in this study. The mean ADC ratios for acute/subacute phase lesions were significantly lower than that for chronic phase lesions. However, some acute/subacute phase lesions had elevated ADCs and these lesions disappeared overtime, implicating a nonischemic mechanism in PACNS.

Cytotoxic edema in neuro-Behcet's disease ?

We report a case of a 52-year-old woman with Behcet's disease who presented with dysarthria and right-sided hemiparesis. T2-weighted and diffusion-weighted images (DWI) showed a hyperintense lesion in the left pons with a relatively decreased apparent diffusion coefficient (ADC). Imaging showed almost complete resolution of the lesion after treatment with prednisolone. The atypical DWI and ADC findings in this case may reflect cytotoxic edema due to excitotoxic brain injury. This case thus illustrates the radiological diversity of neuro-Behcet's lesions.

Diffusion-weighted imaging in chronic Behçet patients with and without neurological findings

Our aim was to investigate whether neurological impairment in chronic Behçet's disease (BD) patients with normal appearing brain can be assessed by means of diffusion-weighted imaging (DWI). The averaged apparent diffusion coefficient (ADC) values were calculated in 22 different radiologically normal appearing brain regions in 32 patients with and without neurological findings and 20 control subjects. The ADC values in bilateral frontal, temporal and occipital normal appearing white matter were significantly higher in the patient groups compared with the control subjects (p < 0.05). In these brain regions, DWI revealed differences in the ADC values between patients with neurological findings (including symptomatic and neuro-Behçet patients) and the asymptomatic patient group. The similarity of the ADC values of patients without symptoms to those of the control group allowed clear discrimination between patients with and without neurological findings. DWI may serve to assess subclinical neurological involvement in BD, even when structural changes are absent.

Central nervous system manifestations of rheumatologic diseases

PURPOSE OF REVIEW

To summarize the current literature on central nervous system manifestations of vasculitides and connective tissue diseases.

RECENT FINDINGS

There have been advances in understanding the mechanisms behind the initiation and perpetuation of inflammatory processes in vasculitic neuropathy. Clinically relevant data have been obtained on the predictive criteria for a positive biopsy result in giant cell arteritis, the imaging characteristics of primary angiitis of the central nervous system, and Behçet disease, and the clinical and radiologic features of neuro-Behçet disease. There is more clarity about the central nervous system syndromes attributable to systemic lupus erythematosus and new insights into the central mechanisms involved in the manifestations of Sjögren syndrome and rheumatoid arthritis. Novel immunomodulatory agents, such as infliximab, have shown some benefit in rheumatoid vasculitis and Sjögren syndrome.

SUMMARY

A better understanding of the clinical, radiographic, and serologic characteristics of various central nervous system complications of rheumatologic diseases has been gained in the past year. Recent advances in understanding the pathophysiology of peripheral nervous system complications and their treatment may affect the management of the central nervous system complications.