Metabolic comorbidities and hypertension in psoriasis patients in France. Comparisons with French national databases.

INTRODUCTION: Several studies have shown a high prevalence of cardiovascular and metabolic comorbidities in psoriasis. Our study aimed to evaluate the association of psoriasis with key comorbidities such as smoking, obesity, hypertension, dyslipidaemia and diabetes comparatively with French national data. MATERIAL AND METHODS: This multicentre noninterventional observational study of adults with psoriasis was conducted in 29 dermatology centres in France. A total of 2210 patients were included. The prevalence of comorbidities in psoriatic patients was compared to data from the French national databanks "ObEpi 2012" (obesity, hypertension, dyslipidaemia and diabetes) and "Baromètre Santé 2010" (smoking). RESULTS: We reported a higher prevalence of all metabolic comorbidities and high blood pressure in psoriatic patients. Smoking: 32.5% were active smokers; the age of onset and the prevalence of familial psoriasis were significantly lower in the smoking group but the severity of psoriasis was significantly higher. The frequency of smoking was higher than in the general population, particularly among young female patients. Obesity: 24% of patients with psoriasis were obese. Multivariate analysis showed obesity to be significantly associated with other comorbidities, severity of psoriasis and psoriatic arthritis. The incidence of obesity was higher than in general population, occurring chiefly in subjects aged over 45 years. HYPERTENSION: 26% of patients with psoriasis had hypertension. The age of onset of psoriasis and the prevalence of psoriatic arthritis were significantly higher in the hypertension group, although there was less familial psoriasis. The incidence of hypertension was higher than in general population. Dyslipidaemia: 27.5% of patients with psoriasis had dyslipidaemia. The age of onset in the dyslipidaemia group was higher although there was less familial psoriasis. The incidence of dyslipidaemia was higher than in general population. Diabetes: 11.0% of patients with psoriasis had diabetes. The age of onset of psoriasis was significantly higher in the diabetes group although there was less familial psoriasis. The incidence of diabetes was higher than in general population particularly after the age of 35 years. CONCLUSION: These results confirmed that psoriasis is associated with significant metabolic comorbidities and hypertension compared to the general population in France, with certain epidemiological differences for each.

Perfusion MRI as a neurosurgical tool for improved targeting in stereotactic tumor biopsies.

OBJECTIVE: Stereotactic biopsies are subject to sampling errors (essentially due to target selection). The presence of contrast enhancement is not a reliable marker of malignancy. The goal of the present study was to determine whether perfusion-weighted imaging can improve target selection in stereotactic biopsies. METHODS: We studied 21 consecutive stereotactic biopsies between June 2009 and March 2010. Perfusion-weighted magnetic resonance imaging (MRI) was integrated into our neuronavigator. Perfusion-weighted imaging was used as an adjunct to conventional MRI data for target determination. Conventional MRI alone was used to determine the trajectory. RESULTS: We found a linear correlation between regional cerebral blood volume (rCBV) and vessel density (number of vessels per mm(2); R = 0.64; p < 0.001). Perfusion-weighted imaging facilitated target determination in 11 cases (52.4%), all of which were histopathologically diagnosed as glial tumors. For glial tumors, which presented with contrast enhancement, perfusion-weighted imaging identified a more precisely delimited target in 9 cases, a different target in 1 case, and exactly the same target in 1 other case. In all cases, perfusion-selected sampling provided information on cellular features and tumor grading. rCBV was significantly associated with grading (p < 0.01), endothelial proliferation (p < 0.01), and vessel density (p < 0.01). For lesions with rCBV values ≤1, perfusion-weighted MRI did not help to determine the target but was useful for surgical management. CONCLUSIONS: For stereotactic biopsies, targeting based on perfusion-weighted imaging is a feasible method for reducing the sampling error and improving target selection in the histopathological diagnosis of tumors with high rCBVs.

Dual, minimally invasive fixation in acute, double, thoracic spine fracture.

BACKGROUND: We report on a dual percutaneous fixation in 2 patients with a double thoracic spine fracture. The advantages and limitations of this new approach for treating traumatic spinal fractures are reviewed. CLINICAL PRESENTATION: A 67-year-old male was admitted following a fall from a height of 3 m. A neurological examination revealed sub-T11 motor and sensory paraparesis. There were a T6 vertical body and bi-articular fracture and a T11 vertebral burst fracture with > 75% posterior wall damage. A 40-year-old male was admitted after a suicide attempt. A neurological examination revealed sub-T11 paraplegia. There were a T7 vertebral body fracture with intact posterior wall and a T11 burst fracture with > 75% posterior wall damage. SURGICAL TECHNIQUE: The same technique was used in both cases. 2 minimally invasive percutaneous fixations of the 2 fractures were performed. In a third step, we performed a T10-T12 open laminectomy. This technique helped to limit blood loss and avoid an over-long fixation. Pedicle screw targeting was optimal. 16 months later, the neurological status was normal in patient 1 and there was neurological improvement in patient 2. No secondary segmental kyphotic deformities appeared.Percutaneous fixation enables the treatment of an acute thoracic spine fracture. With appropriate presurgical planning, this technique can be applied to all thoracic vertebrae. Spinal cord injuries justify the use of laminectomy together with percutaneous fixation, in order to limit erector muscle injury and blood loss.

Security and reliability of CUSTOMBONE cranioplasties: A prospective multicentric study.

BACKGROUND: Repairing bone defects generated by craniectomy is a major therapeutic challenge in terms of bone consolidation as well as functional and cognitive recovery. Furthermore, these surgical procedures are often grafted with complications such as infections, breaches, displacements and rejections leading to failure and thus explantation of the prosthesis. OBJECTIVE: To evaluate cumulative explantation and infection rates following the implantation of a tailored cranioplasty CUSTOMBONE prosthesis made of porous hydroxyapatite. One hundred and ten consecutive patients requiring cranial reconstruction for a bone defect were prospectively included in a multicenter study constituted of 21 centres between December 2012 and July 2014. Follow-up lasted 2 years. RESULTS: Mean age of patients included in the study was 42±15 years old (y.o), composed mainly by men (57.27%). Explantations of the CUSTOMBONE prosthesis were performed in 13/110 (11.8%) patients, significantly due to infections: 9/13 (69.2%) (p<0.0001), with 2 (15.4%) implant fracture, 1 (7.7%) skin defect and 1 (7.7%) following the mobilization of the implant. Cumulative explantation rates were successively 4.6% (SD 2.0), 7.4% (SD 2.5), 9.4% (SD 2.8) and 11.8% (SD 2.9%) at 2, 6, 12 and 24 months. Infections were identified in 16/110 (14.5%): 8/16 (50%) superficial and 8/16 (50%) deep. None of the following elements, whether demographic characteristics, indications, size, location of the implant, redo surgery, co-morbidities or medical history, were statistically identified as risk factors for prosthesis explantation or infection. CONCLUSION: Our study provides relevant clinical evidence on the performance and safety of CUSTOMBONE prosthesis in cranial procedures. Complications that are difficulty incompressible mainly occur during the first 6 months, but can appear at a later stage (>1 year). Thus assiduous, regular and long-term surveillances are necessary.

Immune checkpoint inhibitor treatment of a first cancer is associated with a decreased incidence of second primary cancer.

BACKGROUND: Second primary cancers (SPCs) are diagnosed in over 5% of patients after a first primary cancer (FPC). We explore here the impact of immune checkpoint inhibitors (ICIs) given for an FPC on the risk of SPC in different age groups, cancer types and treatments. PATIENTS AND METHODS: The files of the 46 829 patients diagnosed with an FPC in the Centre Léon Bérard from 2013 to 2018 were analyzed. Structured data were extracted and electronic patient records were screened using a natural language processing tool, with validation using manual screening of 2818 files of patients. Univariate and multivariate analyses of the incidence of SPC according to patient characteristics and treatment were conducted. RESULTS: Among the 46 829 patients, 1830 (3.9%) had a diagnosis of SPC with a median interval of 11.1 months (range 0-78 months); 18 128 (38.7%) received cytotoxic chemotherapy (CC) and 1163 (2.5%) received ICIs for the treatment of the FPC in this period. SPCs were observed in 7/1163 (0.6%) patients who had received ICIs for their FPC versus 437/16 997 (2.6%) patients receiving CC and no ICIs for the FPC versus 1386/28 669 (4.8%) for patients receiving neither CC nor ICIs for the FPC. This reduction was observed at all ages and for all histotypes analyzed. Treatment with ICIs and/or CC for the FPC are associated with a reduced risk of SPC in multivariate analysis. CONCLUSION: Immunotherapy with ICIs alone and in combination with CC was found to be associated with a reduced incidence of SPC for all ages and cancer types.

Validation of transcutaneous bilirubinometry during phototherapy for detection and monitoring of neonatal jaundice in a low-income setting.

Background: Severe neonatal jaundice (SNJ) and the associated long-term health sequelae are a significant problem in low-income countries (LIC) where measurement of total serum bilirubin (TSB) is often unavailable. Transcutaneous bilirubinometry (TcB) provides the opportunity for non-invasive, point-of-care monitoring. Few studies have evaluated its agreement with TSB levels during phototherapy in LIC.Aim: To determine agreement between TcB and TSB during phototherapy in a Haitian newborn population and to establish whether TcB can be safely used to guide treatment during phototherapy when TSB is unavailable.Methods: A single-centre prospective study (February to May 2017) in Cap Haïtien, northern Haiti was undertaken. Newborns <7 days of age with clinically detected jaundice were eligible for inclusion. A TcB device (JM-103) was used to screen for newborn jaundice along with a parallel TSB. A strip of black tape was placed across the sternum during phototherapy and uncovered for subsequent TcB measurements. Decisions about phototherapy treatment were based upon UK National Institute of Clinical Excellence (NICE) threshold criteria. Paired TSB and TcB measurements were compared using Bland-Altman methods.Results: The final analysis included 70 parallel TSB/TcB measurements from 35 infants within the first 5 days of life. Nineteen (54.3%) were male and 12 (34.3%) were <35 weeks. Thirty-two (91.4%) were receiving phototherapy. There was good agreement between TSB and TcB. Compared with TSB, TcB tended to over-estimate bilirubin (mean difference 11.1 µmol/L, 95% CI -10.2-32.5 µmol/L). However, at higher bilirubin levels (>250 µmol/L), TcB tended to under-estimate bilirubin compared with TSB and the difference increased.Conclusion: In an LIC setting in which serum bilirubin testing is not commonly available, TcB demonstrates good agreement with TSB and can be safely used to guide jaundice treatment during phototherapy but can lead to over-treatment at lower bilirubin levels and are more inaccurate at higher levels. For TcB levels >250 µmol, confirmation with serum bilirubin should be performed, if available, to avoid under-estimation.Abbreviations: LIC: low income countries; LMIC: low and middle income countries; TcB: transcutaneous bilirubinometry; TSB: transcutaneous serum biliubin.

Tension pneumocephalus and rhinorrhea revealing spontaneous cerebrospinal fluid fistula of the anterior cranial base.

Spontaneous cerebrospinal fluid fistulas (CSFFs) of the anterior skull base are extremely rare. We report a case of spontaneous CSFF of the ethmoid cribriform plate presenting with rhinorrhea and tension pneumocephalus. We discuss the physiopathology, the radiological management, and the treatment of spontaneous CSF fistulas related to the anterior skull base. A 58-year-old woman was admitted to our institution for headaches with clear rhinorrhea persisting over several days. Antecedents were unremarkable. An episode of epistaxis three days before was reported. Clinical examination showed clear rhinorrhea, headaches, and anosmia. The CT scan showed voluminous epidural and subdural pneumocephalus with mass effect on both frontal and temporal lobes. A high-resolution CT scan with bone reconstruction showed a 2-mm bony defect of the cribriform plate. Surgery consisted of epidural frontal anterior skull base repair. Postsurgery follow-up was uneventful. At one year, the patient was asymptomatic apart from the persistence of anosmia. Spontaneous CSF fistulas are uncommon and can be associated with tension pneumocephalus. The physiopathology remains unclear. Their treatment by complete exclusion of the fistula is necessary because of the lethal risk of pneumococcus meningitis.

[Follicular dural lymphoma. Case report]. / Lymphome folliculaire méningé. A propos d'un cas.

A case of a meningeal B-cell lymphoma is described. A 48-year-old man presented with an episode of grand mal seizure following a brain injury. An initial diagnosis of extradural hematoma was made based on the results of the cerebral computerized tomography scan. Magnetic resonance images demonstrated an enhanced mass with a dural tail attached to the meningeal layer of the temporal bone, suggesting a meningioma "en plaque". The mass was surgically excised. Tumoral removal was subcomplete (Simpson 2). Operative inspection also suggested a meningioma, but histological analysis and electron microscopy revealed a grade IV follicular B-cell lymphoma. Biological studies were normal. An extensive workup found an external iliac adenopathy with several osseous locations on PET. The patient underwent chemotherapy and radiotherapy. Three years after the first symptoms appeared, the patient is alive and free of symptoms. The clinicopathological features and treatments were discussed.

[Giant prebulbomedullary arachnoid cyst. Case report and review of the literature]. / Kyste arachnoïdien géant prébulbomédullaire. Cas clinique et revue de la littérature.

Usual locations of arachnoid cyst are the middle cranial fossa in 50-60%, cerebellopontine angle (10%) and suprasellar area (10%). Most of these malformations are asymptomatic. Premedullar arachnoid cysts are extremely rare. All previous cases reported were operated. We report a case of an asymptomatic giant craniocervical junction arachnoid cyst with a follow up of five years. In 2002, an adolescent consulted for persistent cervical pain. Encephalic MR showed a giant ventral craniocervical junction arachnoid cyst. Neurologic examination was normal. Conservative treatment was decided with a clinical follow up and repeated MR in case of persistent cervicalgia. Craniocervical junction arachnoid cysts are anecdotic. Medical care cannot be standardized. Pathogenesis and management are discussed.

[Giant cystic widening of Virchow-Robin spaces, case report]. / Dilatations géantes des espaces de Virchow-Robin.

INTRODUCTION: Virchow-Robin spaces are very well-known anatomical and radiological entities. However, the observation of giant cystic widening of Virchow-Robin spaces is anecdotic. We report herein the case of a patient presenting with giant cystic widening of Virchow-Robin spaces located in both cerebral hemispheres. OBSERVATION: A 26-year-old female presented with numbness of left arm and then, of both arms. CT scan showed many hypodensities located in the two hemispheres. Neurologic examination was normal. MR imaging allowed the diagnosis of giant cystic widening Virchow-Robin spaces in T2, T2*, T1 gadolinium and Flair weighted images. Neuropsychological investigations were normal. CONCLUSION: Giant cystic widening of Virchow-Robin spaces are extremely rare entities. MR imaging helps the diagnosis. Only extreme dilatation of Virchow-Robin perivascular spaces close to ventricular system must be watched and treated in case of an obstructive hydrocephalus risk. When located in cerebral hemispheres, these dilatations are mostly asymptomatic and must not be confused with a cystic tumoral disease.

The impact of the implementation of a rehabilitation tool on the contents of the communication during multidisciplinary team conferences in rheumatology.

OBJECTIVE: Problems with multidisciplinary team conferences in health care include the exchange of too much (discipline-specific) information. The aim of this study was to investigate the effect of the implementation of a rehabilitation tool on the contents of communication during multidisciplinary team conferences in a rheumatology setting. METHODS: All initial and follow-up team conferences of 25 consecutive patients with rheumatoid arthritis admitted to a day patient care ward were videotaped during a period before (period I) and after (period II) the introduction of a rehabilitation tool. The aims of the rehabilitation tool were to enhance discussions on the co-ordination of care rather than merely exchange of information. This was achieved by providing a framework for the setting and evaluation of common treatment goals and management strategies as well as accompanying electronic and printed records. For every team conference, the duration of time spent on three types of communication was recorded: (1) grounding regarding the patient's health status, (2) the making of practical arrangements by no more than two health professionals, and (3) the co-ordination of common treatment goals or management strategies. Comparisons of the proportions of time spent on the different types of communication between the two periods were done by means of the Mann-Whitney U-test. RESULTS: Apart from the 25 initial team conferences in both periods, 86 and 71 follow-up team conferences were available in periods I and II, respectively. Regarding the initial team conferences, the proportion of time spent on grounding and practical arrangements was significantly smaller in period II than in period I. In addition, the proportion of time spent on common goals or management strategies was significantly greater in period II than in period I. For the follow-up team conferences, the proportion of time spent on practical arrangements was significantly smaller in period II, than in period I. Moreover, the proportions of time spent on the other types of communication did not differ significantly between the two periods. CONCLUSION: The implementation of a rehabilitation tool including a computer application increased the proportion of time spent on the discussion of common treatment goals or management strategies during initial but not during follow-up team conferences in a day patient rheumatology clinic.

[Primary intramedullary lymphoma. Case report]. / Lymphome primitif intramédullaire. A propos d'un cas.

A 66-year-old female presented primary intramedullary spinal cord lymphoma. This patient was referred for lower limbs weakness, which had developed six weeks earlier and right C5 radiculalgia. Physical examination revealed a medullary syndrome with Claude-Bernard-Horner syndrome. The diagnosis was established after MRI and biopsy (dorsal myelotomy). The patient was given chemotherapy and craniospinal adjuvant radiotherapy (30 Grays). The clinical, radiological and therapeutic features are discussed.

[Paraganglioma of the cavernous sinus. Case report]. / Paragangliome du sinus caverneux. A propos d'un cas.

A case of paraganglioma arising from the cavernous area is presented. A 51-year-old woman presented with a parasellar mass causing decreased visual acuity, oculomotor nerve paresis and retro-orbital headaches without endocrinological dysfunction. Diagnosis was confirmed by histological appearance and electron microscopy. The patient was treated with surgery followed by radiation therapy consisting of 45 Gy. The clinicopathological features and the possible pathogenesis are discussed.

[Terminovertebral aneurysm arising from basilar artery fenestration]. / Anevrisme termino-vertebral sur fenestration de l'artere basilaire.

A case of ruptured middle saccular aneurysm arising from basilar artery fenestration is reported. Defects of the medial wall at the junctures of the fenestrated segments explain the association between vertebrobasilar aneurysms and basilar artery fenestration. A 47 year-old woman had a perimesencephalic subarachnoid hemorrhage. Immediate angiography revealed a ventral vertebrobasilar aneurysm and an endovascular coil occlusion was performed. Embryological development, pathogenesis and therapeutic difficulties are discussed.

Lhermitte-Duclos disease and Cowden's syndrome. Report of two cases.

OBJECTIVE AND IMPORTANCE: Lhermitte-Duclos disease, or dysplastic cerebellar gangliocytoma is a rare entity characterized by a hamartomatous lesion in the posterior fossa. Cowden's syndrome, or hamartoma-neoplasia syndrome is a rare underdiagnosed autosomal dominant genodermatosis with high incidence of malignant tumors. Several recent reports suggest that Lhermitte-Duclos disease may be a component of Cowden's syndrome. CLINICAL PRESENTATION: We report two cases of Lhermitte-Duclos and Cowden disease occurring in adult patients. A 40-year-old woman had symptoms of raised intracranial pressure and macrocephaly. She displayed the stigmata of fibrocystic breast disease, thyroid goitre. Clinical examination showed mucocutaneous lesions. Her mother, brother and uncle had manifestations of Cowden's disease. An asymptomatic 38-year-old male had bilateral optic nerve drusen related to a cerebellar neoplasm. He exhibited manifestations of Cowden's syndrome and his familial history confirmed this hypothesis. INTERVENTION: The first patient was operated on for Lhermitte-Duclos disease. A conservative strategy was performed for the second patient and the clinical and imaging follow-ups were uneventful over 5 years. CONCLUSION: We stress the possibility that Lhermitte-Duclos and Cowden disease might be a peculiar form of phakomatosis. A conservative strategy can be chosen without neurological signs because of slow tumor growth. However, these patients should be carefully examined and followed up because of the risk of future malignancy.

[3D reconstruction of anterior internal vertebral venous plexus of a human fetus: a feasibility study]. / Reconstruction tridimensionnelle des plexus veineux vertébraux internes et antérieurs d'un foetus humain: étude de faisabilité.

Anterior internal vertebral venous plexus have been studied extensively due to their clinical importance in diseases of the spine and obstruction of the inferior vena cava. The aim of this feasibility study was to reconstruct in 3D the lower thoracic area of the anterior epidural space of a 69 mm (crown-rump) human fetus from the Rouvière Collection, circa 1927. Forty slices (spaced by 40 microm) at the level of the tenth and eleventh thoracic vertebrae, and their lower adjacent intervertebral discs, were reconstructed in 3D using the commercial software SURFdriver. In a preliminary study, we had found that the structures of the epidural space are already formed at this stage of development, and that they are comparable to the adult stage (2002). Reconstruction of the microscopic slices in 3D allowed to better visualize spatially the structures of the venous plexus and their anatomical relationships. This technique could be used as a complement to the classically used histological studies.

Early role of vascular dysregulation on late-onset Alzheimer's disease based on multifactorial data-driven analysis.

Multifactorial mechanisms underlying late-onset Alzheimer's disease (LOAD) are poorly characterized from an integrative perspective. Here spatiotemporal alterations in brain amyloid-ß deposition, metabolism, vascular, functional activity at rest, structural properties, cognitive integrity and peripheral proteins levels are characterized in relation to LOAD progression. We analyse over 7,700 brain images and tens of plasma and cerebrospinal fluid biomarkers from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Through a multifactorial data-driven analysis, we obtain dynamic LOAD-abnormality indices for all biomarkers, and a tentative temporal ordering of disease progression. Imaging results suggest that intra-brain vascular dysregulation is an early pathological event during disease development. Cognitive decline is noticeable from initial LOAD stages, suggesting early memory deficit associated with the primary disease factors. High abnormality levels are also observed for specific proteins associated with the vascular system's integrity. Although still subjected to the sensitivity of the algorithms and biomarkers employed, our results might contribute to the development of preventive therapeutic interventions.

Pilot study of the development of a theory-based instrument to evaluate the communication process during multidisciplinary team conferences in rheumatology.

BACKGROUND: Coordinated teams with multidisciplinary team conferences are generally seen as a solution to the management of complex health conditions. However, problems regarding the process of communication during team conferences are reported, such as the absence of a common language or viewpoint and the exchange of irrelevant or repeated information. To determine the outcome of interventions aimed at improving communication during team conferences, a reliable and valid assessment method is needed. AIM: To investigate the feasibility of a theory-based measurement instrument for assessing the process of the communication during multidisciplinary team conferences in rheumatology. METHOD: An observation instrument was developed based on communication theory. The instrument distinguishes three types of communication: (I) grounding activities, (II) coordination of non-team activities, and (III) coordination of team activities. To assess the process of communication during team conferences in a rheumatology clinic with inpatient and day patient facilities, team conferences were videotaped. To determine the inter-rater reliability, in 20 conferences concerning 10 patients with rheumatoid arthritis admitted to the inpatient unit, the instrument was applied by two investigators independently. Content validity was determined by analysing and comparing the results of initial and follow-up team conferences of 25 consecutive patients with rheumatoid arthritis admitted to the day patient unit (Wilcoxon signed rank test). RESULTS: The inter-rater reliability was excellent with the intra-class correlation coefficients being >0.98 for both types I and III communications in 10 initial and 10 follow-up conferences (type II was not observed). An analysis of an additional 25 initial and 86 follow-up team conferences showed that time spent on grounding (type I) made up the greater part of the contents of communication (87% S.D. 14 and 60% S.D. 29 in initial and follow-up conferences, respectively), which is significantly more compared to time spent on co-ordination (p<0.001 and 0.02 for categories II and III, respectively). Moreover, significantly less time spent was spent on grounding in follow-up as compared to initial team conferences, whereas the time spent on coordination (type III) increased (both p-values<0.001). CONCLUSION: This theory-based measurement instrument for describing and evaluating the communication process during team conferences proved to be reliable and valid in this pilot study. Its usefulness to detect changes in the communication process, e.g. after implementing systems for re-structuring team conferences mediated by ICT applications, should be further examined.

Melanocytic schwannomas. Report of three cases.

OBJECTIVE AND IMPORTANCE: Melanocytic tumors are rare. The literature reports less than 40 cases and suggests that they behave aggressively, can recur and progress to malignancy. CLINICAL PRESENTATION: We report three patients with melanocytic schwannomas located in the cervical spine, in the thoracic spine and in the lumbar spine. In the two first cases, these symptoms were a spinal cord compression whereas the last patient presented symptoms of cruralgy. IMAGING: MRI always showed an extramedullary intradural tumor arising from the root destroying the intervertebral foramen. INTERVENTION: The patients underwent laminectomy and the excision was complete. Immunohistochemical stains were positive to S100 and HMB45 antibodies. The evolution was unfavourable for two patients with local recurrence and leptomeningeal metastasis. CONCLUSION: These three cases demonstrate that melanocytic schwannomas have a guarded prognosis because of their metastatic potential, especially for young people.

L-arginine infusion increases basal but not activated cerebral blood flow in humans.

Nitric oxide is a potent vasodilator. Infusion of its precursor, L-arginine, results in increased cerebral blood flow (CBF) in experimental animals. We examined the effects of L-arginine infusion on CBF in humans using positron emission tomography and the quantitative H2(15)O method. Six subjects received 500 ml of 0.9% NaCl solution, and six subjects received an infusion of L-arginine (16.7 mg/kg/min; 500 mg/kg). Before and after the i.v. infusion, paired CBF measurements were performed at baseline and with vibrotactile stimulation of the right hand. In scans performed without vibrotactile stimulation, mean whole-brain CBF increased from 34.9 +/- 3.7 ml 100 g-1 min-1 to 38.2 +/- 4.4 ml 100 g-1 min-1. (9.5%; p < 0.005) after L-arginine infusion. The temporal pattern of CBF changes differed from that of plasma growth hormone and insulin levels and of arterial pH. In contrast, in the saline group, mean whole-brain CBF did not change significantly (35.8 +/- 5.9 ml 100 g-1 min-1 to 35.9 +/- 6.4 ml 100 g-1 min-1; 0.3%). Vibrotactile stimulation produced significant focal increases in CBF, which were unaffected by L-arginine infusion. L-arginine infusion was associated with an increase in plasma L-citrulline, a byproduct of nitric oxide synthesis.