Safe long-term repeated disruption of the blood-brain barrier using an implantable ultrasound device: a multiparametric study in a primate model.

OBJECTIVE The main limitation to the efficacy of chemotherapy for brain tumors is the restricted access to the brain because of the limited permeability of the blood-brain barrier (BBB). Previous animal studies have shown that the application of pulsed ultrasound (US), in combination with the intravenous injection of microbubbles, can temporarily disrupt the BBB to deliver drugs that normally cannot reach brain tissue. Although many previous studies have been performed with external focused US transducers, the device described in the current work emits US energy using an unfocused transducer implanted in the skull thickness. This method avoids distortion of the US energy by the skull bone and allows for simple, repetitive, and broad disruption of the BBB without the need for MRI monitoring. The purpose of the present study was to determine if the BBB can be safely and repeatedly disrupted using such an implantable unfocused US device in a primate model. METHODS An 11.5-mm-diameter, 1-MHz, planar US device was implanted via a bur hole into the skull of 3 primates (2 Papio anubis [olive] baboons and 1 Macaca fascicularis [macaque]) for 4 months. Pulsed US sonications were applied together with the simultaneous intravenous injection of sulfur hexafluoride microbubbles (SonoVue) every 2 weeks to temporarily disrupt the BBB. In each primate, a total of 7 sonications were performed with a 23.2-msec burst length (25,000 cycles) and a 1-Hz pulse repetition frequency at acoustic pressure levels of 0.6-0.8 MPa. Potential toxicity induced by repeated BBB opening was analyzed using MRI, PET, electroencephalography (EEG), somatosensory evoked potential (SSEP) monitoring, behavioral scales, and histopathological analysis. RESULTS The T1-weighted contrast-enhanced MR images acquired after each sonication exhibited a zone of hypersignal underneath the transducer that persisted for more than 4 hours, indicating a broad region of BBB opening in the acoustic field of the implant. Positron emission tomography images with fluorine-18-labeled fluorodeoxyglucose (FDG) did not indicate any changes in the cerebral metabolism of glucose. Neither epileptic signs nor pathological central nerve conduction was observed on EEG and SSEP recordings, respectively. Behavior in all animals remained normal. Histological analysis showed no hemorrhagic processes, no petechia, and extravasation of only a few erythrocytes. CONCLUSIONS The studies performed confirm that an implantable, 1-MHz US device can be used to repeatedly open the BBB broadly in a large-animal model without inducing any acute, subacute, or chronic lesions.

Long-term outcome of infliximab in severe chronic and refractory systemic sarcoidosis: a report of 16 cases.

OBJECTIVES: Infliximab (IFX) appears to be effective in refractory sarcoidosis. However, data are lacking regarding its efficacy in severe sarcoidosis (i.e. with cardiac and/or neurological involvement). METHODS: Retrospective single-centre study including 16 unselected consecutive patients with biopsy proven, severe, and resistant sarcoidosis, who were treated by infliximab (3 or 5 mg /kg at 0, 2 and 6 weeks, then every 8 weeks) between 2005 and 2013. RESULTS: Following IFX therapy we observed an improvement in 92% of cases, with a marked decrease of the severity score [median score 6 (3-12) vs. 2 (1-8), p<0.0001] and trend toward steroid sparing effect [12.5 (0-40) vs. 8.5 mg/d (0-30), p=0.11] between baseline and the end of follow-up, respectively. Regarding the index organ response, we observed a remission of cardiac and central nervous system involvements in 4 out of 4 and 11 out 12 cases, respectively. Thirty-eight percent of patients experienced a relapse. After a median follow-up of 57 months (2 to 91), we observed 7 (44%) infectious complications, 1 paradoxical cutaneous granuloma and 1 leucoencephalopathy. Infectious complications were mostly observed in male [6/7 (86%), p=0.06], with a longer duration of steroids (108 vs. 39 months, p=0.11) and immunosuppressant use prior IFX (42 vs. 24 months, p=0.08) compared to their negative counterpart, respectively. CONCLUSIONS: IFX was efficient in severe and refractory sarcoidosis. Infectious complications were frequent and occurred mainly in male patients with longer duration of steroids and immunosuppressant use prior to IFX.

Reproducible and sustained efficacy of targeted therapy with vemurafenib in patients with BRAF(V600E)-mutated Erdheim-Chester disease.

PURPOSE: Histiocytoses are rare disorders with heterogeneous prognosis. BRAF(V600E) mutations have been observed in half of patients with Langerhans cell histiocytosis (LCH) and in 50% to 100% of patients with Erdheim-Chester disease (ECD) patients. We recently reported short-term efficacy of a BRAF inhibitor (vemurafenib) in three patients with multisystemic ECD. PATIENTS AND METHODS: Vemurafenib was given to eight patients with multisystemic ECD with CNS and/or cardiac involvement. All patients were refractory to first-line treatment and harbored a BRAF(V600E) mutation. Four patients also had LCH lesions. Positron emission tomography (PET) scan response at month 6 was used as the main evaluation criterion. Secondary evaluation criteria were comparison at baseline and at last visit of PET and of cardiovascular and cerebral infiltrations (computed tomography scan and magnetic resonance imaging [MRI]). RESULTS: All patients were partial metabolic responders at 6 months of vemurafenib, and the median reduction in maximum standardized uptake value was 63.5% (range, 41.3% to 86.9%). Evaluation of cardiac and aortic infiltrations showed that seven patients had a partial response and one patient had stable disease according to surface measurements derived from RECIST criteria. The four patients with infratentorial CNS infiltration had an objective decrease of the lesions on MRI. All patients had an improvement of general symptoms and a persistent response to vemurafenib, with a median follow-up time of 10.5 months (range, 6 to 16 months). Skin adverse effects were frequent and severe. CONCLUSION: Vemurafenib has an objective and sustained efficacy in BRAF(V600E)-mutated ECD as second-line therapy. In contrast to melanoma, no resistance has emerged to date after 6 to 16 months.

Long-term outcome of neuro-Behçet's disease.

OBJECTIVE: To report the long-term outcome of neurologic involvement in patients with Behçet's disease (BD). METHODS: We performed a retrospective analysis of 115 patients who fulfilled the international criteria for BD (57% male; median age 37 years [interquartile range (IQR) 30-46 years]) and had neuro-BD (NBD) after exclusion of cerebral venous thrombosis. Factors associated with relapse of NBD, inability to perform activities of daily living, and mortality were assessed. RESULTS: Seventy-eight patients (68%) presented with acute NBD and 37 (32%) presented with a progressive course. The HLA-B51 allele was carried by 49% of the patients. Overall, 46 of 115 patients (40%) had severe disability at baseline, represented by a Rankin score of ≥3. The 5- and 7-year event-free survival rates were 65% and 53%, respectively. In multivariate analysis, a positive HLA-B51 status was independently associated with the risk of NBD relapse, with an odds ratio (OR) of 3.6 (95% confidence interval [95% CI] 1.5-9.1). After a median followup of 73 months (IQR 59-102 months), 29 patients (25.2%) became dependent (were unable to perform activities of daily living) or died. Factors independently associated with poor outcome were paresis at onset (OR 6.47 [95% CI 1.73-24.23]) and location of inflammatory lesions at the brainstem on magnetic resonance imaging (OR 8.41 [1.03-68.43]). All 115 patients were treated with corticosteroids; 53 (46.1%) also took cyclophosphamide and 40 (34.8%) also took azathioprine. A trend toward longer event-free survival was observed in patients with severe NBD (i.e., with a Rankin score of ≥3 at onset) receiving intravenous cyclophosphamide compared with those receiving azathioprine (P = 0.06). CONCLUSION: Our findings indicate that NBD is a severe condition in which patients with the HLA-B51 allele appear to experience a worse prognosis.

The cognitive spectrum in neurodegenerative Langerhans cell histiocytosis.

Clinical spectrum of cognitive troubles complicating neurodegenerative Langerhans cell histiocytosis (ND-LCH) is poorly known. The aim of this study is to evaluate cognitive functions in ND-LCH. The cognitive functions of a series of eight adult patients (7 males and 1 female; mean age 26 years IQ 25-75; range 20-33) suffering from clinical and/or radiological ND-LCH were evaluated using the following tests: (1) forward/backward digit and spatial span tasks of the WAIS-R scale and the Corsi block task, (2) the French version of the free and cued selective reminding test, (3) verbal fluency tests, (4) the Frontal Assessment Battery (FAB), (5) backward measurement of the verbal and visuospatial memories of the WAIS-R scale, (6) the Rey complex figure test, (7) the trail making tests A and B, (8) digit symbol and symbol search of the WAIS-IV scale, and (9) the Stroop test. Episodic (i.e. autobiographical or personal) memory free recall, categorical verbal fluency, phonological verbal fluency, visuospatial processing skills, attention, speed of processing, and sensitivity to interference were impaired in ND-LCH patients. In contrast, verbal and visuospatial short-term memories (i.e. immediate memories or forward span tasks) were preserved in all patients. Adult ND-LCH patients suffer from a severe but dissociated dysexecutive syndrome, mostly affecting executive strategies and relatively sparing short-term memory. Our study supports the need of assessing executive functions using comprehensive cognitive evaluation in ND-LCH patients for early diagnosis.

Extensive basal ganglia edema caused by a traumatic carotid-cavernous fistula: a rare presentation related to a basal vein of Rosenthal anatomical variation.

The authors report a very rare presentation of traumatic carotid-cavernous fistula (CCF) with extensive edema of the basal ganglia and brainstem because of an anatomical variation of the basal vein of Rosenthal (BVR). A 45-year-old woman was admitted to the authors' institution for left hemiparesis, dysarthria, and a comatose state caused by right orbital trauma from a thin metal rod. Brain MRI showed a right CCF and vasogenic edema of the right side of the brainstem, right temporal lobe, and basal ganglia. Digital subtraction angiography confirmed a high-flow direct CCF and revealed a hypoplastic second segment of the BVR responsible for the hypertension in inferior striate veins and venous congestion. Endovascular treatment was performed on an emergency basis. One month after treatment, the patient's symptoms and MRI signal abnormalities almost totally disappeared. Basal ganglia and brainstem venous congestion may occur in traumatic CCF in cases of a hypoplastic or agenetic second segment of the BVR and may provoke emergency treatment.

Dramatic efficacy of vemurafenib in both multisystemic and refractory Erdheim-Chester disease and Langerhans cell histiocytosis harboring the BRAF V600E mutation.

Histiocytoses are rare disorders of unknown origin with highly heterogeneous prognosis. BRAFV600E gain-of-function mutations have been observed in 57% of cases of Langerhans cell histiocytosis (LCH) and 54% of cases of Erdheim-Chester disease (ECD), but not in other types of histiocytoses. Targeted therapy with an inhibitor of mutated BRAF (vemurafenib) improves survival of patients with melanoma. Here, we report vemurafenib treatment of 3 patients with multisystemic and refractory ECD carrying the BRAFV600E mutation; 2 also had skin or lymph node LCH involvement. The patients were assessed clinically, biologically (CRP values), histologically (skin biopsy), and morphologically (positron emission tomography [PET], computed tomography and magnetic resonance imaging). For all patients, vemurafenib treatment led to substantial and rapid clinical and biologic improvement, and the tumor response was confirmed by PET, computed tomography, and/or magnetic resonance imaging 1 month after treatment initiation. For the first patient treated, the PET response increased between months 1 and 4 of treatment. The treatment remained effective after 4 months of follow-up although persistent disease activity was still observed. Treatment with vemurafenib, a newly approved BRAF inhibitor, should be considered for patients with severe and refractory BRAFV600E histiocytoses, particularly when the disease is life-threatening.

Prediction of subacute infarct size in acute middle cerebral artery stroke: comparison of perfusion-weighted imaging and apparent diffusion coefficient maps.

PURPOSE: To compare perfusion-weighted (PW) imaging and apparent diffusion coefficient (ADC) maps in prediction of infarct size and growth in patients with acute middle cerebral artery infarct. MATERIALS AND METHODS: This study was approved by the local institutional review board. Written informed consent was obtained from all 80 patients. Subsequent infarct volume and growth on follow-up magnetic resonance (MR) images obtained within 6 days were compared with the predictions based on PW images by using a time-to-peak threshold greater than 4 seconds and ADC maps obtained less than 12 hours after middle cerebral artery infarct. ADC- and PW imaging-predicted infarct growth areas and infarct volumes were correlated with subsequent infarct growth and follow-up diffusion-weighted (DW) imaging volumes. The impact of MR imaging time delay on the correlation coefficient between the predicted and subsequent infarct volumes and individual predictions of infarct growth by using receiver operating characteristic curves were assessed. RESULTS: The infarct volume measurements were highly reproducible (concordance correlation coefficient [CCC] of 0.965 and 95% confidence interval [CI]: 0.949, 0.976 for acute DW imaging; CCC of 0.995 and 95% CI: 0.993, 0.997 for subacute DW imaging). The subsequent infarct volume correlated (P<.0001) with ADC- (ρ=0.853) and PW imaging- (ρ=0.669) predicted volumes. The correlation was higher for ADC-predicted volume than for PW imaging-predicted volume (P<.005), but not when the analysis was restricted to patients without recanalization (P=.07). The infarct growth correlated (P<.0001) with PW imaging-DW imaging mismatch (ρ=0.470) and ADC-DW imaging mismatch (ρ=0.438), without significant differences between both methods (P=.71). The correlations were similar among time delays with ADC-predicted volumes but decreased with PW imaging-based volumes beyond the therapeutic window. Accuracies of ADC- and PW imaging-based predictions of infarct growth in an individual prediction were similar (area under the receiver operating characteristic curve [AUC] of 0.698 and 95% CI: 0.585, 0.796 vs AUC of 0.749 and 95% CI: 0.640, 0.839; P=.48). CONCLUSION: The ADC-based method was as accurate as the PW imaging-based method for evaluating infarct growth and size in the subacute phase.

Is radiological evaluation as good as computer-based volumetry to assess hippocampal atrophy in Alzheimer's disease?

INTRODUCTION: Hippocampus volumetry is a useful surrogate marker for the diagnosis of Alzheimer's disease (AD). Our purpose was to compare visual assessment of medial temporal lobe atrophy made by radiologists with automatic hippocampal volume and to compare their performances for the classification of AD, mild cognitive impairment (MCI) and cognitively normal (CN). METHODS: We studied 30 CN, 30 MCI and 30 AD subjects. Six radiologists with two levels of expertise performed two readings of medial temporal lobe atrophy. Medial temporal lobe atrophy was evaluated on coronal three-dimensional T1-weighted images using Scheltens scale and compared with hippocampal volume obtained using a fully automatic segmentation method (Spearman's rank coefficient). RESULTS: Visual assessment of medial temporal lobe atrophy was correlated with hippocampal volume (p < 0.01). Classification performances between MCI converter and CN was better using volumetry than visual assessment of non-expert readers whereas classification of AD and CN did not differ between visual assessment and volumetry except for the first reading of one non-expert (p = 0.03). CONCLUSIONS: Visual assessment of medial temporal lobe atrophy by radiologists was well correlated with hippocampal volume. Radiological assessment is as good as computer-based volumetry for the classification of AD, MCI non-converter and CN and less good for the classification of MCI converter versus CN. Use of Scheltens scale for assessing hippocampal atrophy in AD seems thus justified in clinical routine.

Cerebral, facial, and orbital involvement in Erdheim-Chester disease: CT and MR imaging findings.

PURPOSE: To retrospectively review the brain magnetic resonance (MR) imaging and computed tomographic (CT) findings in patients with Erdheim-Chester disease (ECD). MATERIALS AND METHODS: The ethics committee required neither institutional review board approval nor informed patient consent for retrospective analyses of the patients' medical records and imaging data. The patients' medical files were retrospectively reviewed in accordance with human subject research protocols. Three neuroradiologists in consensus analyzed the signal intensity, location, size, number, and gadolinium uptake of lesions detected on brain MR images obtained in 33 patients with biopsy-proved ECD. RESULTS: Thirty patients had intracranial, facial bone, and/or orbital involvement, and three had normal neurologic imaging findings. The hypothalamic-pituitary axis was involved in 16 (53%) of the 30 patients, with six (20%) cases of micronodular or nodular masses of the infundibular stalk. Meningeal lesions were observed in seven (23%) patients. Three (10%) patients had bilateral symmetric T2 high signal intensity in the dentate nucleus areas, and five (17%) had multiple intraaxial enhancing masses. Striking intracranial periarterial infiltration was observed in three (10%) patients. Another patient (3%) had a lesion in the lumen of the superior sagittal sinus. Nine (30%) patients had orbital involvement. Twenty-four (80%) patients had osteosclerosis of the facial and/or skull bones. At least two anatomic sites were involved in two-thirds (n = 20) of the patients. Osteosclerosis of the facial bones associated with orbital masses and either meningeal or infundibular stalk masses was seen in eight (27%) patients. CONCLUSION: Lesions of the brain, meninges, facial bones, and orbits are frequently observed and should be systematically sought on the brain MR and CT images obtained in patients with ECD, even if these patients are asymptomatic. Careful attention should be directed to the periarterial environment.

18F-fluorodeoxyglucose-positron emission tomography scanning is more useful in followup than in the initial assessment of patients with Erdheim-Chester disease.

OBJECTIVE: Erdheim-Chester disease (ECD) is a rare form of non-Langerhans' cell histiocytosis. The aim of this study was to assess the value of whole-body scanning with (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in a large cohort of ECD patients from a single center. METHODS: We retrospectively reviewed all PET scans performed on 31 patients with ECD who were referred to our department between 2005 and 2008. PET images were reviewed by 2 independent nuclear medicine specialist physicians and were compared with other imaging modalities performed within 15 days of each PET scan. RESULTS: Thirty-one patients (10 women and 21 men; median age 59.5 years) underwent a total of 65 PET scans. Twenty-three patients (74%) were untreated at the time of the initial PET scan, whereas 30 of the 34 followup PET scans (88%) were performed in patients who were undergoing immunomodulatory therapy. Comparison of the initial and followup PET scans with other imaging modalities revealed that the sensitivity of PET scanning varied greatly among the different organs studied (range 4.3-100%), while the specificity remained high (range 69.2-100%). Followup PET scans were particularly helpful in assessing central nervous system (CNS) involvement, since the PET scan was able to detect an early therapeutic response of CNS lesions, even before magnetic resonance imaging showed a decrease in their size. PET scanning was also very helpful in evaluating the cardiovascular system, which is a major prognostic factor in ECD, by assessing the heart and the entire vascular tree during a single session. CONCLUSION: The results of our large, single-center, retrospective study suggest that the findings of a FDG-PET scan may be interesting in the initial assessment of patients with ECD, but its greater contribution is in followup of these patients.