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Context: in patients with acute brain injury, upholding of cerebral blood flow (CBF) is essential to prevent cerebral ischemia. Brain tissue oxygen (PbtO2) monitoring is recommended in patients at risk. Intravascular volume expansion is used to increase PbtO2. The aim of our study was to explore predictors of an increase in PbtO2 after a volume expansion. Methods: we included patients admitted to ICU for acute brain injury, who were monitored with PbtO2 and for whom a volume expansion was performed to optimize cardiac output or CBF. Cardiac index (CI) was measured using transpulmonary thermodilution (TPTD) or transthoracic echocardiography (TTE). Hemodynamic and cerebral datasets were collected before and after the intervention. Intervention consisted in a volume expansion (500 mL crystalloids) volume expansion over 10 minutes. An increase of 10% or more in PbtO2 value following volume expansion was defined as significant. Results: 56 patients were included in the analysis. 49 (87.5%) were admitted for subarachnoid hemorrhage (SAH). 26 (46%) patients had a significant increase in PbtO2. In multivariable analysis, MAP variation following volume expansion was significantly associated with an increase in PbtO2 of more than 10% [OR = 1.68; 95% CI: 1.01 - 2.80; p=0.0464] unlike CI variation [OR=1.32; 95% CI: 0.90 - 1.93; p=0.1572]. Transcranial Doppler measurements did not show significant influence of middle cerebral artery blood flow velocity on the increase in PbtO2. Conclusion: a volume expansion increases PbtO2, mainly because of MAP increase and not because of cardiac output increase., Introduction : chez les patients cérébrolésés, le maintien du débit sanguin cérébral (DSC) est essentiel afin de prévenir l’ischémie cérébrale. Le monitorage de la pression tissulaire en oxygène (PtiO2) est recommandé chez les patients à risque. Le remplissage vasculaire est utilisé pour augmenter la PtiO2. L’objectif de notre étude était d’identifier les facteurs associés à une augmentation de la PtiO2 après un remplissage vasculaire. Matériels et méthodes : les critères d’inclusion étaient des patients majeurs admis en neuroréanimation ayant un monitorage cérébral par PtiO2, et pour qui un remplissage vasculaire était réalisé afin d’optimiser le débit cardiaque ou le DSC. L’index cardiaque (IC) était mesuré via la thermodilution transpulmonaire (TDTP) ou l’échographie cardiaque transthoracique (ETT). L’intervention consistait en un remplissage vasculaire de 500 mL de cristalloïdes sur 10 minutes. Une augmentation de la PtiO2 de 10% ou plus après le remplissage vasculaire était définie comme significative. Résultats : 56 patients ont été inclus dans l’analyse. 49 (87.5%) étaient admis pour une hémorragie sous-arachnoïdienne (HSA). 26 (46%) patients avaient une augmentation significative de la PtiO2. En analyse multivariée, la variation de la pression artérielle moyenne (PAM) suivant le remplissage vasculaire était significativement associée à une augmentation de la PtiO2 de plus de 10% (OR=1.68 ; IC95% [1.01-2.80] ; p=0.0464) à la différence de l’index cardiaque (OR=1.32 ; IC95% [0.90-1.93] ; p=0.1572). Conclusion : un remplissage vasculaire augmente la PtiO2, principalement grâce à l’augmentation de la PAM et non pas par l’augmentation du débit cardiaque.

Sickle cell disease is the leading genetic disease in Île-de-France. Stroke is one of its most severe complications. In SS sickle cell children, transcranial Doppler (TDC) is, through the study of average speeds of the skull base arteries, the gold standard for screening and diagnosis of vasculopathy. To our knowledge, in adults with sickle cell disease, no standards have been established for the speed of the arteries at the base of the skull. It therefore seemed useful to us to establish an approach to brain speeds recorded in adults with sickle cell disorders without neurovascular complications.This was an observational, prospective, monocentric study conducted between February 2017 and June 2017. The main objective of the study was to determine the mean and standard deviation of maximum systolic velocities (MSS) and mean maximum velocities for all arteries recorded during the transcranial Doppler echo. The secondary objectives were to compare the mean maximum systolic velocities in sickle cell adults with those of healthy adults, to compare the mean maximum systolic velocities in sickle cell adults with those of sickle cell children, and to determine whether parameters could influence the speeds recorded at TCD.Forty patients were included between February 1, 2017 and June 30, 2017, with an average age of 39.3 years. The mean maximum velocities recorded were: 78cm/s for the middle cerebral arteries; 59.6cm/s for the internal carotid arteries; 61cm/s for the anterior cerebral arteries; 44cm/s for the posterior cerebral arteries and 55cm/s for the basilar trunk.The highest circulatory velocities are found in the middle cerebral arteries. The speeds found in the internal carotid arteries and anterior cerebral arteries are faster than in the vertebrobasilar system. Speeds in sickle cell adults are slower than those described in sickle cell children SS but significantly faster than those found in healthy adults.To our knowledge, this study is the first to evaluate transcranial Doppler circulatory velocities in adult sickle cell patients. This work has limitations due to its small sample size, however, it provides a basis for further studies on transcranial Doppler in sickle cell adults.

The rupture of an intracranial aneurysm is a sudden, unpredictable and potentially severe event. The responsible aneurysm has to be excluded from the cerebral circulation to avoid recurrence. More and more commonly, intracranial aneurysms are detected by coincidence. How to react to these fortuitous discoveries is unclear, because the risk of rupture is difficult to estimate. We present our approach to patients facing this situation and the decision-making process.La rupture d’un anévrisme intracrânien est un événement aigu, imprévisible et aux conséquences potentiellement gravissimes. Le traitement passe par l’exclusion de la malformation anévrismale de la circulation sanguine afin d’éviter une nouvelle rupture. De plus en plus fréquemment, en raison des progrès de l’imagerie, les anévrismes sont découverts fortuitement. L’attitude à adopter dans ce type de situation reste incertaine, car le risque de rupture est difficile à évaluer. Nous présentons notre manière de prendre en charge cette situation, notre approche du patient, les facteurs qui conditionnent notre décision, et comment nous orientons notre démarche en cas de traitement prophylactique.

Cerebral vasoreactivity (CVR) is the ability of the brain's vascular system to keep cerebral blood inflow stable. Impaired CVR is a risk marker of stroke in patients with asymptomatic carotid stenosis. The gold standard to assess CVR with transcranial ultrasound is acetazolamide (ACTZ) injection. The breath holding test (BHT) might be easier to perform. CVR proved to be efficient in laboratory conditions but not in routine practice.To study the validity of BHT versus ACTZ in routine practice in a vascular exploration unit in patients with asymptomatic carotid stenosis.Study of concordance of BHT and ACTZ, to assess CVR in patients consecutively explored on the same day.Eighteen patients with 20 carotid stenosis were included. The temporal window was missing in 20% of cases. Only 11 out of the 20 procedures were analyzed. Concordance was low between BHT and ACTZ to assess CVR (k=0.3714).BHT cannot replace ACTZ injection. It might be a first-step test so that ACTZ injection might be avoided if CVR is normal. Our present results must be confirmed by further study enrolling many more patients.

BackgroundImplantation of self-expanding stents from the parent artery into the sac of a bifurcation aneurysm is regularly used to facilitate endovascular coil occlusion with the so-called waffle cone technique (WCT). Self-expanding aneurysm bridging stents like Solitaire AB, can be used; however, bifurcation devices like pCONus and pCANvas are especially designed for WCT. These devices provide additional support for coil implantation owing to intraluminal nylon fibers (pCONus) or membranes (pCANvas) covering the intracranial aneurysm neck.ObjectiveAssessment of the intra-aneurysmal hemodynamic impact of these three devices: a regular intracranial stent (Solitaire AB) and two bifurcation devices (pCONus and pCANvas).Material and methodsAn in vitro experiment was set up using a silicone model of a basilar tip aneurysm filled with blood mimicking fluid under a pulsatile circulation. Solitaire AB, pCONus, and pCANvas were successively implanted in the model for hemodynamic evaluation. High frame rate DSA series were acquired under various conditions. Intra-aneurysmal flow changes, including mean aneurysm flow amplitude ratio (R), were subsequently assessed by the optical flow method, measuring the detector velocity field before and after device implantations.ResultspCONus and Solitaire minimally reduced the intra-aneurysmal flow (R=0.96, p=0.17 and R=0.91, p=0.01, respectively), whereas pCANvas strongly diminished the intra-aneurysmal flow (R=0.41, p=5×10−12).ConclusionsWaffle cone deployment of stents and technique-specific devices had no undesirable effect on the intra-aneurysmal flow. In particular, no increased flow was redirected into the aneurysm sac. The intraluminal membrane of the pCANvas strongly reduced the intra-aneurysmal flow, potentially preventing recanalization problems.

Technological innovations have endowed the development of powerful tools in medical imaging, such as transcranial color-coded sonography. In addition to other imaging techniques, its relevance in cerebrovascular disorders is increasing. This article aims to describe the technique through specification of its current indications in patients with arterial cervical and intracranial stenosis.

The management of cerebral perfusion pressure (CPP) is the one of the main preoccupation for the care of paediatric traumatic brain injury (TBI). The physiology of cerebral autoregulation, CO2 vasoreactivity, cerebral metabolism changes with age as well as the brain compliance. Low CPP leads to high morbidity and mortality in pediatric TBI. The recent guidelines for the management of CPP for the paediatric TBI indicate a CPP threshold 40-50 mmHg (infants for the lower and adolescent for the upper). But we must consider the importance of age-related differences in the arterial pressure and CPP. The best CPP is the one that allows to avoid cerebral ischaemia and oedema. In this way, the adaptation of optimal CPP must be individual. To assess this objective, interesting tools are available. Transcranial Doppler can be used to determine the best level of CPP. Other indicators can predict the impairment of autoregulation like pressure reactivity index (PRx) taking into consideration the respective changes in ICP and CPP. Measurement of brain tissue oxygen partial pressure is an other tool that can be used to determine the optimal CPP.

To review the current research and formulate a rational approach to the physiopathology, cause and treatment of post-dural puncture headache (PDPH).Articles published to December 2011 were obtained through a search of Medline for the MeSh terms "epidural blood-patch" and "post-dural puncture headache".Six hundred and eighty-two pertinent studies were included and 200 were analysed.Resulting of a dural tap after spinal anaesthesia or diagnostic lumbar puncture or as a complication of epidural anaesthesia, PDPH occurs when an excessive leak of cerebrospinal fluid leads to intracranial hypotension associated to a resultant cerebral vasodilatation. Reduction in cerebrospinal fluid volume in upright position may cause traction of the intracranial structure and stretching of vessels. Typically postural, headache may be associated to nausea, photophobia, tinnitus or arm pain and changes in hearing acuity. In severe cases, there may be cranial nerve dysfunction and nerve palsies secondary to traction on those nerves. The Epidural Blood-Patch (EBP) is considered as the "gold standard" in the treatment of PDHP because it induces a prolonged elevation of subarachnoid and epidural pressures, whereas such elevation is transient with saline or dextran. EBP should be performed within 24-48hours of onset of headache; the optimum volume of epidural blood appears to be 15-20mL. Severe complications following EBP are exceptional. The use of echography may be safety puncture. The optimum timing of epidural blood-patch, the resort of repeating procedure if the symptomatology does not disappear, the alternative to the conventional medical treatment need to be determined by future clinical trial.

Although embolism and hypoperfusion may well occur concurrently in a non-negligible proportion of cerebral infarction patients, there is currently lack of proof, especially in the posterior circulation. Here, we are reporting on a case of multiple cerebral infarctions in a patient with neurofibromatosis type 1, multiple vascular abnormalities of the posterior cerebral circulation and intracranial artery occlusion. We hypothesize that cerebral blood flow impairment may have affected the clearance and destination of embolic particles.

Isoflurane, desflurane and sevoflurane all preserve cerebrovascular carbone dioxide (CO(2)) reactivity. They are all concentration-dependant cerebral vasodilatators and decrease cerebral metabolism. Sevoflurane induces the smallest cerebral vasodilatation and preserve cerebral autoregulation up to 1.5CAM, compared to isoflurane and desflurane which impair it upon 1CAM. Propofol has been compared to inhaled agents. Propofol preserve cerebrovascular CO(2) reactivity, blood flow-metabolism coupling, cerebral autoregulation and has no vasodilatation effect. None of the three inhaled agents induce any clinical relevant increase of intracranial pressure (ICP), but studies were conducted in patients without any intracranial hypertension (ICHT). However, compared to propofol, ICP and brain swelling were higher with inhaled agents, more with isoflurane compared to sevoflurane. Finally, neuroprotective properties have been described in experimental model for all the inhaled agents but clinical proofs are still lacking. In conclusion, for intracranial surgery without any ICHT inhaled agents can be used as a maintenance anesthetic with a preference for sevoflurane. In case of ICHT or a risk of ICHT during the surgery, propofol is preferred for it slightest effect on ICP and cerebral hemodynamic.

The main purpose of neurointensive care is to fight against cerebral ischaemia. Ischaemia is the cell energy failure following inadequacy between supply of glucose and oxygen and demand. Ischemia monitoring starts with a global approach, especially with cerebral perfusion pressure (CPP) determined by mean arterial pressure and intracranial pressure (ICP). However, global monitoring is insufficient to detect "regional" ischaemia, leading to development of local monitoring such as brain oxygen partial pressure (PtiO(2)). PtiO(2) is measured on a volume of a few mm(3) from a probe implanted in the cerebral tissue. The normal value is classically included between 25 and 35 mmHg and critical ischemic threshold is 10 mmHg. Understanding what exactly is PtiO(2) is still a matter of debate. PtiO(2) is more an indicator of oxygen diffusion depending of oxygen arterial pressure (PaO(2)) and local cerebral blood flow (CBF). Increase PaO(2) to treat PtiO(2) would hide information about local CBF. PtiO(2) is useful for the detection of low local CBF even when ICP is low as in hypocapnia-induced vasoconstriction. PtiO(2)-guided management could lead to a continuous optimization of arterial oxygen transport for an optimal cerebral tissue oxygenation. Finally, PtiO(2) has probably a global prognostic value because studies showed that hypoxic values for a long period of time lead to an unfavourable neurologic outcome. In conclusion, PtiO(2) provides additional information for regional monitoring of cerebral ischaemia and deserves more intensive use to better understand it and probably improve neurointensive care management.

The clinical importance of cardiovascular consequences resulting from cerebral injury has long been recognized. However, interactions between the brain and the cardiovascular system remain poorly defined and their importance for the management of patients suffering from acute brain injury is largely underestimated. This should have profound consequences on treatment strategies during anaesthesia and intensive cares of these patients, taking into account not only brain perfusion, but also cardiovascular optimisation. This report summarizes the main data available regarding the cardiovascular consequences of brain death, traumatic brain injury, stroke and epilepsy.

Cranioplasty after decompressive craniectomy in patients suffering from severe head injury often leads to a functional improvement although, to date, the pathophysiology of this phenomenon remains unclear. A few hypotheses have been proposed. The impact of cranioplasty on cerebral perfusion could be one explanation. We have evaluated the impact of cranioplasty on the functional status of patients undergoing decompressive craniectomy for severe head injury with its influence on cerebral perfusion.Twenty-four patients undergoing craniectomy for severe head injury were included in this multi-centric and prospective study. All of them had a cranioplasty within 12 weeks following decompressive craniectomy. A clinical and radiological evaluation was performed prior to and after cranioplasty. Neurological and cognitive evaluation was performed with the Glasgow Outcome Score (GOS), the Frontal Assessment Battery (FAB) and the Mini Mental State Examination (MMSE). Radiological evaluation was performed by perfusion CT scan and transcranial Doppler.A statistically significant neurological and cognitive improvement was observed in 92% of patients at 6 months follow-up (F-U). Brain perfusion was improved at 6 weeks F-U, predominantly in the affected hemisphere. Systolic and diastolic blood velocity flow were improved in both middle cerebral arteries.Cranioplasty after decompressive craniectomy for patients suffering from severe head injury probably improves the functional outcome of these patients, thanks to a global improvement of cerebral perfusion.

Orthostatic hypotension (OH) is defined as a decrease in systolic blood pressure more than or equal to 20 mm Hg or diastolic more than or equal to 10 mm Hg within three minutes of standing up. Discharge records for 0.4% of all hospitalizations include OH as a diagnosis. The prevalence of OH is related to aging, reaching 5 to 30% in unselected elders aged more than or equal to 65 years, especially those treated for hypertension and/or living in nursing homes or health care facilities. OH is associated with an increased risk of syncope and subsequent cardiovascular mortality. Standing results in pooling of 25-30% of blood in the lower extremities and splanchnic-mesenteric circulation, thereby reducing venous return, ventricular filling, cardiac output and, in turn, blood pressure. Compensatory mechanisms to maintain BP involve the baroreflex and the sympathetic nervous system (SNS). Failure of SNS results in neurogenic OH, which is severe in multiple system atrophy with dysautonomia (Shy-Drager syndrome), also commonly seen in patients with Lewy body dementia and in patients with Parkinson's disease, in whom OH is less severe and occurs later. Conversely, SNS function is preserved in secondary OH associated with hypovolemia, anemia, antihypertensive or psychotropic drugs. Clinical manifestations and tolerance of OH depends on its severity and on cerebral blood flow autoregulation, which both impact on the risk of syncope, trauma and subsequent prognosis.

Tumors of the frontal horn of the lateral ventricle (LV) are only supplied by the posteromedial choroidal artery. Tumors of the body of the LV are supplied by the same artery. Tumors of the atrium of the LV with anterior extension are supplied by both posteromedial choroidal and posterolateral arteries. Tumors of the atrium with inferior extension are supplied by both anterior choroidal artery and posterolateral choroidal arteries. Tumors of the inferior horn are only supplied by anterior choroidal artery. The tumoral venous drainage is organized with three main groups of veins: a medial group, a lateral group and a choroidal group.

Floating carotid thrombi are a rare cause of stroke mostly associated with atheromatous plaques, cardiogenic emboli, arterial dissections and systemic diseases related to coagulopathic states or iron deficiency anaemia. We report the cases of two patients with stroke and carotid megabulb or suspended bulb associated with floating thrombus. These findings are rarely described probably related to a form of arterial dysplasia and seem to be responsible of local haemodynamic modifications.

Dementia of Lewy bodies (DLB) is the second cause of degenerative dementia. There is many clinical presentation of the disease. Brain single photon computed tomography (SPECT) is a simple way to investigate routinely the cerebral blood flow. On cerebral perfusion SPECT, DLB is accompanied by diffuse cortical hypoperfusion predominantly at the posterior cortex and may affect the associative and primary visual areas in relation to neuronal loss or dysfunction. DLB patients have striatal hypofixation on cerebral neurotranmission SPECT-DaTSCAN(®), related with dopaminergic loss. Brain SPECT is useful in the differential diagnosis between DLB and other dementia.

Environmental reduplication which is characterized by reduplication of places has been reported in right hemispheric lesions, particularly but not only in the right frontal region. However, spatial delirium may follow right sub-cortical lesions.We describe a 53 years-old man who had a reduplicative paramnesia for event alone after an intracerebral haematoma of the right caudate nucleus.MRI Scan showed also an extension of the right caudate nucleus haemorrhage into the ventricular system. Regional cerebral blood flow studied with 99Tcm-HMPAO showed a decrease of perfusion in the right dorso-lateral frontal cortex. To our knowledge, we reported the first case of reduplicative paramnesia of event associated with a right caudate nucleus injury. Similar right frontal deactivation was observed in two cases of reduplicative paramnesia for place, one of them after an infarction of the retro-lenticular portion of the right internal capsulae, the other after a right thalamo-capsular haemorrhage.We suggest that reduplicative paramnesia for event, like the previous cases reported of reduplicative paramnesia for place, may be linked to a subcortical lesion of the frontal lobe inducing a right functional frontal deactivation.

To study efficacy, systemic and cerebral haemodynamic, and cost of sedation with sevoflurane after midazolam failure.Prospective observational study in a mixed intensive care unit.Mechanically ventiled patients in whom deep sedation failed (Ramsay score5 despite midazolam 10mg/h and fentanyl 400μg/h) were enrolled. Sedation with sevoflurane and fentanyl (200μg/h) was performed during 48 hours. Sevoflurane was administered with a dedicated filter (AnaConDa™) and sevoflurane infusion rate was adjusted in order to achieve a Ramsay score ≥5. Ramsay score, mean arterial blood pressure, norepinephrine dose/24h, intracranial pressure and cerebral perfusion pressure in patients with brain injury were measured. Directs costs for sedation were calculated. An analysis of variance for repeated measures compared values between D0 (intravenous sedation), D1 and D2 (inhaled sedation).Twenty-five patients (age=51 [38-63], SAPS II=43 [33-49]) were enrolled. Ramsay score was 4 [4,5] at D0 and 6 [6] at D1 and D2 (P0.05 vs D0). Mean arterial pressure was significantly lower at D1 (80 [73-86] mmHg) as compared to D0 (84 [77-92] mmHg) and D2 (84 [78-91] mmHg) (P0,05). Norepinephrine consumption was lower at D2 as compared to D1 (P0,05). Intracranial pressure was lower at D1 (9 [5-13] mmHg) and D2 (11 [7-15] mmHg) as compared to D0 (12 [7-17] mmHg) (P0.05). PPC was stable at D1 and increased at D2. Directs costs were significantly increased with sevoflurane.Sevoflurane is an effective and safe alternative to midazolam in ICU patients associated with a moderate increase in costs.

Cerebrospinal fluid biomarkers are a fundamental contribution for the diagnosis of Alzheimer disease, in particular for young people.We report a case of Alzheimer disease of a 51-years old man whose clinical presentation corresponded to frontotemporal behavioural criteria. The clinical evaluation noticed some troubles in verbal memory. Only the CSF biomarkers confirmed the diagnosis.There are different phenotypes of presenile Alzheimer disease and among them we note frontotemporal dementia. It is very important to identify them to introduce a specific treatment.

Anticancer treatments-induced central nervous system neurotoxicity has become a major problem in recent years. Real advances in therapeutic results for cancer treatments have improved patients' survival. Nowadays, central nervous system radiation therapy is widely prescribed, both for palliative and curative treatments in the management of malignant or benign tumors. Recent data on tolerance of normal central nervous system to radiation therapy are reviewed here, early and delayed radiation-induced effects are described and dose recommendations are suggested for clinical practice.

We investigated the relationship between tumor blood-flow measurement based on perfusion-imaging by arterial spin-labeling (ASL) and histopathologic findings in adults' primitive glial tumours.Thus, 40 primitive brain tumors (8 low-grade and 32 high-grade gliomas according to the Sainte-Anne classification) were imaged using pulsed (n=19) or continuous (n=21) ASL. Relative cerebral blood flow (rCBF=tumoral blood flow/normal cerebral blood flow) between high- and low-grade gliomas were compared.Using pulsed ASL, differences in mean rCBF were observed in high- and low-grade gliomas although no significant (respectively 1.95 and 1.5). Using continuous ASL, mean rCBF were significantly higher for high-grade than for low-grade gliomas (P0.05). High-grade gliomas could be discriminated using a CBF threshold of 1.18, with a sensitivity of 88%, specificity of 60%, predictive positive value of 88%, and predictive negative value of 60%.ASL-based perfusion provides a quantitative, non-invasive alternative to dynamic susceptibility contrast perfusion MR methods for evaluating CBF. ASL is a suitable method for gliomas initial staging and could be useful to identify intermediate tumoral evolution.

International audience; PURPOSE: Pilocytic astrocytomas (PA) and hemangioblastomas (HB) can present the same morphological characteristics on conventional MRI sequences, most usually in the form of a cerebellar cystic mass with a mural nodule that strongly enhances on post-contrast T1 images. We discuss here the value of perfusion MRI in the differentiation of these two tumors, the diagnoses of which have already been histopathologically established. METHOD: Eleven patients with PA and eight with HB underwent first-pass perfusion MRI. The maximum relative cerebral blood volume (rCBV(max)), defined as the ratio between the CBV(max) in tumor tissue and the CBV in healthy, contralateral white matter, is considered to be indicative of the type of tumor. RESULTS: The difference between the rCBV(max) of PA (rCBV(max)=1.19+/-0.71, range 0.6-3.27) compared with that of HB (rCBV(max)=9.37+/-2.37, range 5.38-13) was significant (P

Reversible cerebral vasoconstriction syndrome (RCVS) is more frequent than previously thought and is probably underdiagnosed. The mean age of onset is 42 years, and it affects slightly more women than men. RCVS is attributed to a transient, reversible dysregulation of cerebral vascular tone, which leads to multifocal arterial constriction and dilation. More than half the cases (60%) are secondary to exposure to vasoactive substances (e.g., cannabis, antidepressants, and nasal decongestants) or occur in the postpartum period. RCVS has a characteristic clinical and radiological course, developing in a single phase after a sudden onset, and there is generally no new event after 1 month. The main pattern of presentation begins with recurrent thunderclap headaches, often triggered by sexual activity or various Valsalva's maneuvers, over a period of 1 to 3 weeks. Seizures and focal neurological deficits are less frequent and generally start after the headaches. Cortical subarachnoid hemorrhage (22%), intracerebral hemorrhage (6%), seizures (3%), and reversible posterior leukoencephalopathy (9%) are early complications, occurring mainly within the first week. Ischemic events, including TIAs (16%) and cerebral infarction (4%), occur significantly later than hemorrhagic strokes, mainly during the second week. Diagnosis requires the demonstration of the characteristic "string and beads" on cerebral angiography and can be difficult, for 21% of patients have a normal initial magnetic resonance angiography (MRA) and 9% both a normal MRA and a normal transcranial Doppler. In these cases, the initial investigations must be repeated after a few days. The final diagnosis is made when a follow-up MRA shows resolution or at least marked improvement of the arterial abnormalities within 12 weeks. RCVS is sometimes associated with other large artery lesions of the head and neck, including dissections and unruptured aneurysms, especially during the postpartum period. Nimodipine is the treatment most often recommended. In our experience, it is not especially effective in severe RCVS. Relapses are possible but rare and have not yet been reported in prospective series. Although the exact pathophysiology remains speculative, strong recommendations against vasoactive substances appear prudent.

Cerebrospinal fluid leakage is a rare but critical condition with a substantial risk of intracranial infection, therefore its diagnosis and treatment is of major importance. CSF leakage diagnostic can be a challenging problem. Nephelometric measurement of beta-trace protein in the liquorrhoea is a non-invasive and fast method that can be used for CSF leakage diagnosis. It should kept in mind, however, that the cut-off of 1.1 mg/L is not suitable for patients with bacterial meningitis and those with a reduced glomerular filtration rate. Complementary use of beta-trace protein assay and beta2-transferrin detection is therefore recommended.

Spontaneous dissection of cervical arteries is one of the major causes of stroke in young patients. The recommended treatment is curative anticoagulation. However, in selected cases, this treatment could fail or meet contraindications. In such cases, an endovascular stent-assisted angioplasty could be successful.We report the case of a 47-year-old patient with spontaneous dissection of the carotid and vertebral arteries. Despite optimized anticoagulant therapy, cerebral perfusion was low. An endovascular stent-assisted angioplasty was performed in the intra- and extracranial segments of the right internal carotid artery. Consequently by improving the intracranial circulation, normal functioning was restored with no immediate complications and the patient remained free of complications at 16-month follow-up.Dissections of cervical arteries that lead to a chronic reduction in brain perfusion might benefit from endovascular stent-assisted angioplasty.

The blood-brain barrier provides the central nervous system with a unique protection against the toxic effects of many xenobiotics. This protection results from the unique anatomic and biological structure of the endothelium of blood vessels in the brain. The main features of the blood-brain barrier are the presence of tight intercellular junctions which strictly limit the diffusion of blood-borne solutes and cells into the brain and the polarized expression of transporters which specifically control the cerebral availability of nutrients, drugs or xenobiotics. Recent findings in molecular and cellular biology improved our knowledge of blood-brain barrier permeability and its regulation. The importance of these findings has been recently highlighted by the description of dysfunctions of the blood-brain barrier which could have an impact on the pathophysiology of several neurological diseases. This review focuses on recent advances in our understanding of blood-brain barrier biology and physiology, presenting the structural organization of the blood-brain barrier and the functional regulation of solute permeability and cellular transendothelial migration.

How human language has evolved remains enigmatic. It is plausible to assume that mutual constraints of speech perception and production mechanisms shaped spoken communication. Speaking and understanding (speech) depend on performance limits of the related sensory and motor systems. Hence, the auditory apparatus evolved to understand speech as it is produced by the motor system, and the motor system such as to produce a signal that is decodable by the auditory system. Two theories attempt to bridge the functional properties of perceptual and motor language systems to account for the physical characteristics of the speech signal.

Transient global amnesia (TGA) is characterized by a severe disturbance of memory, occurring rapidly, lasting less than a day and mainly affecting elderly subjects. During its acute phase, it is characterized by a severe anterograde amnesia, partial retrograde amnesia and anxiety with repetition of the same questions. The diagnosis is purely based on patient's clinical features. Complimentary examinations are only requested when atypical symptoms are present. The pathophysiology of TGA remains unknown, but it appears to be related to transient disturbances of the perfusion and oxygenation of the hippocampal structures, following a precipitating factor (stress, effort...). Spontaneous recovery is usual in less than 24 hours and without sequelae. Relapse is rare. Nevertheless, TGA represents a psychological traumatism pathology for the patients and their family.

In neurosurgery, the question of the optimal transfusion "trigger" remains a controversial matter. Regarding the brain, the current data are still incomplete, justifying the continuation of experimental and clinical studies. The existing expert advices are based on these rather poor data and would probably evolve after the completion of clinical studies in progress. In spine surgery, the situation is simpler and the transfusional stakes are quite similar to those of orthopedics and traumatology. With regard to hemostasis, standardized recommendations exist depending on the laboratory test results or the anticoagulant treatments of the patient.

Without precise international recommendations, despite the advances of the ISUAA study, the superiority of microsurgery or endovascular treatment for unruptured intracranial aneurysm (UIA) over the natural history of this disease has not been proved. In this context, the authors evaluate their experience with the aim of assessing the results and risks of the different therapeutics and comparing them with the natural risk of this disease.From January 1993 to July 2000, 79 patients harboring 110 UIAs were treated. These patients were divided retrospectively into two groups. Group A included 45 operated patients. Group B included 37 patients treated with endovascular coiling. The therapeutic choice was not randomized and was approved by a multidisciplinary neurovascular staff.The two populations were homogeneous in terms of age and sex. In group A, 12 patients presented early complications (26.6 %), with one death. In group B, 15.6 % of the patients presented an ischemic complication. After 1 year of follow-up, morbidity was 11.4 % in group A and 4.8 % for group B. Angiography found a partial recanalization in 12.5 % of the operated patients and in 33 % of the patients treated with endovascular coiling.Many factors are involved in the therapeutic decision: UIA location and size and individual risks. Progress in both surgery and interventional neuroradiology has led to good results conforming with the data reported in the literature but does not demonstrate the superiority of one technique over another.

The relationships between the brain and arterial hypertension are strong. The brain, through the hypothalamus, can quickly adapt the blood pressure level to maintain the cerebral blood flow. An acute increase in blood pressure, if it overtakes the autoregulatory capacities, needs an urgent intervention to decrease neurological problems such as encephalopathy. In chronic situations, arterial hypertension is a frequent cause of stroke, either ischemic or hemorragic, both in patients free and those who have already suffered from brain damage. Hypertension is also an actor in the genesis of vascular, but also Alzheimer's dementia. A strict control of blood pressure (but also in other atherosclerotic risk factors) into the normal range is needed to protect the brain, and this is more important than the choice of a particular class of antihypertensive agents, except the betablockers. The risk starts from the normal values of blood pressure.

The aim of this paper was to describe gait disorders and their consequences in primary dementias, and to prove the positive impact of their prevention and rehabilitation.The most relevant articles on gait and dementias available on Medline were analyzed.The prevalence of gait and balance disorders is between 9 and 52% in Alzheimer-type dementia in which frontal gait and apraxic gait are described. Gait disorders, appearing with a prevalence of over 71% in vascular dementia, seem to be an early indicator of this dementia in which hemiparetic gait, frontal gait and unsteady gait are commonly described. As clinical practice shows, gait disorders appear to be frequent in dementia with Lewy bodies and Parkinson's dementia, both being characterized by Parkinsonian gait; however, there are very few prevalence studies concerning gait disturbances in these two dementias. The balance and gait assessment in demented subjects is based on the analysis of sit-to-stand/back-to-sit and one-leg balance, the measurement of gait speed, the Timed-Up-and-Go and the dual task tests. Although there are few studies on the topic, the benefit of the motor rehabilitation on functional independency in demented subjects is now recognized. The programs used for motor rehabilitation of demented people must be individual with targeted objectives, and associate strength and balance exercises, attentional tasks, immediate and working memories and praxis, in the context of multidisciplinary intervention. However, there is no consensus on a standard rehabilitation program of demented subjects.Future studies have to analyse gait disorders in demented subjects in order to clarify their pathophysiology. Besides, they may confirm the benefit of rehabilitation and suggest consensual programs.

Moyamoya disease is rare among non-Asian populations and its clinical features are ill-defined. We report 12 new cases of Moyamoya disease in French, non-Asian adults.We identified adults with Moyamoya disease managed at a French University Hospital from 1998 through 2006. We reviewed baseline clinical and radiological data and collected follow-up data between March and June 2008. The risk of recurrent stroke was determined using the Kaplan-Meier method.Twelve patients, 10 women and two men, were included. The mean age at baseline was 31.1 years. The initial clinical manifestation was ischemic stroke in 10 patients. The disease was clinically asymptomatic in two patients. The mean follow-up in the 10 symptomatic patients was 52.4 months. Only one patient was surgically treated. The one and five-year risk of recurrent stroke were both 50%. At the end of the follow-up, one patient was dead, four patients had no functional impairment (grade 0-1 on the Rankin scale), and seven patients had moderate functional impairment (grade 2-3 on the Rankin scale). A cognitive dysfunction as identified by failure on the Trail Making Test part B was found in six of ten patients evaluated.Moyamoya disease in this cohort of French, non-Asian adults was associated with high rates of both recurrent stroke and cognitive impairment. The findings suggest that Moyamoya disease in non-Asian adults is a potentially severe disease.

Ictal single photon emission computed tomography (SPECT) reflects epileptic activity through hyperperfusion associated with ictal discharge. It provides valuable spatial information on ictal activity, but its temporal resolution is limited. Therefore, information provided by SPECT is not restricted to the epileptogenic zone, but demonstrates a larger epileptogenic network, related to the spatiotemporal dynamics of ictal processes. This review includes a description of the technique, followed by a description of the different parameters likely to influence the ictal perfusion images. SPECT gives contributes original diagnostic data to the decision-making process which will complete, the other evaluation parameters.

To assess the contribution of ictal SPECT to the definition of the epileptogenic zone (EZ) prior to surgery in focal drug-resistant epilepsies, we investigated the effect of the timing of injection and seizure semiology on patterns of perfusion and cerebral blood flow changes (CBF) beyond the EZ. In the rat model of amygdala-kindled seizures, we measured CBF changes with the quantitative [(14)C]-iodoantipyrine autoradiographic method during secondary generalized (SGS, n=26 fully-kindled rats) and focal seizures (FS, n=19 partially kindled rats), according to sequential timing of injection with respect to seizure onset. During SGS, the correct lateralization and rough localization of the focus within limbic structures was only possible at the early ictal and post-ictal times, in between we observed widespread rCBF increases. The switch from hyper to hypoperfusion occurred at the time of late ictal injection. The accurate localization of the EZ was obtained in the study of the more subtle FS (stage 0). At stage 1 of the kindling, there was already a remote widespread spreading of hyperperfusion. In patients surgically cured from a mesio-temporal lobe epilepsy (mean post-operative follow-up: 66 months), we retrospectively studied 26 pairs of ictal and interictal pre-operative SPECTs, classified in 3 groups according to the progression of ictal semiology. Using visual analysis of subtracted SPECTs (SISCOM) and group comparisons with a control group (using SPM), we observed more widespread combined hyper and hypoperfusion with the increasing complexity of seizures. In simple partial seizures, the SISCOM analysis allowed a correct localization of the focus in 4/8 patients, whereas the SPM analysis failed to detect significant changes, due to individual variation, spatial normalization and small magnitude of CBF changes. In complex partial seizures with automatisms, SISCOM and SPM analysis showed antero-mesial temporal hyperperfusion (overlapping the EZ), extending to the insula, basal ganglia, and thalamus in the group of patients having dystonic posturing (DP group) in addition to automatisms. Ictal hypoperfusion involved pre-frontal and parietal regions, the anterior and posterior cingulate gyri, to a greater extent in the DP group. In both human and animals studies, we observed a correlation between the extent of composite patterns of hyper/hypoperfusion and the severity of seizures, and the recruitment of remote sub-cortical structures. Hypoperfused areas belong to neural networks involved in perceptual decision making and motor planning, whose transient disruption could support purposeless actions, i.e. motor automatisms.

Transcranial doppler (TCD) is a noninvasive and easily repeatable method to measure the blood flow in basal cerebral arteries. Mean velocities of red blood cells in basal arteries are related to cerebral blood flow. Because of low peripheral resistance in cerebral arteries, diastolic velocity (V(d)) remains positive in cerebral circulation in physiological situations. The pulsativity index (PI; normal values for the middle cerebral artery=1.0+/-0.2) and end diastolic velocity (EDV; normal values for the middle cerebral artery=40+/-10 cm/s) give important information to evaluate the resistance status of small downstream arteries. A high PI (1.4) with a low EDV (20 cm/s) indicates a low blood flow with a high ischemic risk due to low cerebral perfusion pressure. TCD can also detect cerebral vasospasm after subarachnoid hemorrhage, but sensitivity and specificity for vasospasm diagnosis are low compared to angiography. However, a day-to-day increase in arterial blood cell velocities can help determine the vasospasm risk and/or indicate that angiography should be done.

International audience; Red wine polyphenolic compounds (RWPC) possess numerous neuroprotective activities that may be beneficial for treating cerebral ischemia. To investigate the in vivo effects of an acute treatment with RWPC during stroke, male Wistar rats were subjected to transient ischemia for 90min and immediately treated with RWPC. The extracellular concentrations of excitatory amino acids, free radical scavengers and energy metabolites during occlusion and reperfusion were monitored using microdialysis. The brain lesions were measured 24h after reperfusion using immunohistological staining. We found that acute treatment with RWPC significantly reduced the burst of amino acids glutamate, aspartate and taurine in response to ischemia and increased the levels of free radical scavengers ascorbic and uric acids during occlusion or at early reperfusion, respectively. The concentration of glucose was improved during occlusion whereas the level of lactate strongly decreased during reperfusion in RWPC treated animals, suggesting an increased use of this substrate by surviving neurons. RWPC also significantly improved blood flow during reperfusion and brain tissue preservation as observed 24h after MCAO in treated animals. These findings strongly suggest that RWPC are agents able to fight against the excitotoxic, oxidative pathways and metabolic dysfunction induced by cerebral ischemia.

Delayed neurological deficit occurs among 30% of patients after aneurysmal subarachnoid haemorrhage, mainly related to cerebral vasospasm. The early detection of cerebral ischemia remains problematic. Conventional cerebral monitoring (as intracranial pressure and cerebral perfusion pressure) appears to be insufficient, because cerebral ischemia may occur without elevated intracranial pressure. Global cerebral monitoring as venous jugular oxygen saturation are useful for regional monitoring. Local monitoring as oxygen tissue partial pressure (PtiO2) and microdialysis are sensible for brain ischemia detection, but may also ignore episodes occurring in non-monitored brain area. For the detection of most episodes of brain ischemia, several monitoring system should be use performing a multimodal intracerebral monitoring. Brain microdialysis and oxygen tissue partial pressure are promising monitoring system.

A subarachnoid haemorrhage (SAH) is frequent after a severe head injury. Traumatic-SAH is associated with a bad outcome and may induce cerebral vasospasm. There is no agreement on the treatment based on the amount of traumatic-SAH. Non-aneurysmal SAH accounts for 15% of all causes of non-traumatic SAH. There is a risk of cerebral vasospasm, although less frequent than after aneurysmal rupture. The improvement in imaging techniques has decreased the frequency of idiopathic SAH.