Surgical management of Moyamoya disease and syndrome: Current concepts and personal experience.

In this focus, we review, in the light of the recent literature, the modalities and indications of surgical cerebral revascularization for Moyamoya (MM) disease or syndrome. We also report our experience in the surgical management of adult MM. In symptomatic forms, with presence of severe disturbances of perfusion or cerebrovascular reactivity on multimodal imaging work-up, the risks of recurrent ischemic or hemorrhagic stroke is high (respectively 10-13%/yr and 2-7%/yr). The objective of treatment is to augment cerebral perfusion (in ischemic forms) or to reduce lenticulo-striate neovessel overload (in hemorrhagic forms), by initiating the development of a cortical neovascularization and/or by directly increasing cerebral blood flow. The risk of immediate postoperative death or stroke is similar between indirect and direct or combined techniques and respectively 0-0.5% and 3-6%, provided a strict perioperative anesthetic management is applied (normocapnia, normoxia and controlled hypertension). Indirect techniques (i.e. encephalo-duro-arterio-myo-periosteo-synangiosis or multiple burr-holes) are technically easy, allow wide cortical revascularization and are very efficient in children: absence of clinical recurrence in more than 95% of cases and presence of a good neovascularization in 83%. However, their effect is delayed for several months, the impact on the hemorrhagic risk is moderate and the global response is uncertain in adults. Direct (superficial temporal artery to middle cerebral artery bypass) or combined techniques improve cerebral blood flow immediately and significantly. They are associated with a higher rate of stroke-free survival at 5 years (95% vs 85%). A recent randomized study has proven that they could reduce the hemorrhagic risk by 2- to 3-fold in comparison with conservative treatment alone. However, their feasibility in children is limited by the very small size of vessels. We present also our results in the surgical management of 12 adult MM patients (mean age 41.3, sex ratio=1) operated between 2009 and 2014 (14 revascularization procedures: EDAMS 2, multiple burr-holes 1, combined revascularization procedures 11). MM types according to clinical presentation were the following: ischemic 8, hemorrhagic 2, combined 2. All patients were recently symptomatic, with recurrent ischemic/hemorrhagic events (2/3) or crescendo neurological deficit (1/3) in association with severe alterations of cerebral blood flow. Mean clinical and radiological follow-up was 22 months. Postoperative mRS at 6 months was improved or stable in 92%. None of the patients suffered recurring stroke. In conclusion, surgical treatment should be discussed quickly in symptomatic forms of MM (progressive or recurring) because of their poor outcome. Indirect techniques are favored in pediatric patients due to their simplicity and good clinical results. Direct, or preferentially combined techniques would be more effective in adult patients to prevent the recurrence of ischemic or hemorrhagic stroke.

Multidisciplinary management of intracranial aneurysms: The experience of Lille university hospital center.

BACKGROUND: In recent years, the multidisciplinary approach has become an important concern for the management of intracranial aneurysms. OBJECTIVE: This study aims to evaluate the functional outcomes of patients treated for an intracranial aneurysm (ruptured or unruptured), when the treatment modality was defined in a multidisciplinary fashion. MATERIALS AND METHODS: In this retrospective study, we included all patients (n=209) treated for an intracranial saccular aneurysm at Lille university hospital between January 2009 and December 2009. There were 70 men and 139 women with a mean age of 50.5 years (range 24 to 73 years). The clinical data were recorded before treatment including the American Society of Anesthesiology (ASA) and the World Federation of Neurosurgical Societies (WFNS) scores. Microsurgical approach was performed in 110 patients whereas 99 patients underwent an endovascular procedure. A modified Rankin Scale (mRS) was reported at 3 months after treatment. Intracranial vascular imaging was performed before and immediately after the treatment and then renewed at 3 years in all patients to detect any recurrence. RESULTS: Among the 121 patients with ruptured aneurysm, the functional outcomes were similar between patients who underwent microsurgery and patients who had an endovascular treatment. In the 88 patients with an unruptured aneurysm, functional outcomes were also similar between the two treatment modalities. Among the 99 patients treated by the endovascular approach, 4 had a significant aneurysm reopening on follow-up imaging leading to additional treatment (3 clipping, 1 coiling). No aneurysm recurrence was reported among the 110 patients who underwent microsurgical treatment. CONCLUSION: In a trained team, the multidisciplinary approach appears to be a valuable strategy in the management of intracranial aneurysms, to achieve good functional outcomes.

Rate of intravenous thrombolysis for acute ischaemic stroke in the North-of-France region and evolution over time.

The proportion of patients with ischaemic stroke treated by intravenous (i.v.) recombinant tissue plasminogen activator (rt-PA) is an indicator of quality of stroke care. The objective of the study is to evaluate the rate of i.v. thrombolysis in the North-of-France region and its evolution over time. We determined the proportion of inhabitants treated by i.v. rt-PA in 2009-2010 (period A; 8 stroke units, no telemedicine) and 2012 (period B; population campaigns, 12 stroke units with telemedicine in 5). We used hospital registries from the 12 stroke units, and population-based data were collected in a subpopulation of 226,827 inhabitants (5.6% of the whole population). 1,563 inhabitants received i.v. rt-PA for stroke (period A: 835 in 24 months; period B: 728 in 12 months). Hospital and population data were similar. Annual rates of thrombolysis increased from 103 per million inhabitants [95% confidence interval (CI) 85-125] to 181 (95% CI 157-209; relative increase 76%, 95% CI 67-83%). This rate increased in 12 districts (significantly in 6), but the increase was greater in districts where new stroke units, telemedicine, or both were implemented. In conclusion, although the proportion of patients treated was already high in period A, there was still place for improvement. Implementation of new stroke units, extension of the telemedicine network and new population campaigns are necessary to improve the rate of thrombolysis in several areas, to ensure an equal access to treatment over the whole territory. The next step is now to determine whether this high rate of i.v. rt-PA delivery at the population level translates into clinical results.

Relations between the plastid gene dosage and the levels of 16S rRNA and rbcL gene transcripts during amyloplast to chloroplast change in mixotrophic spinach cell suspensions.

Spinach cell suspension cultures maintained in photomixotrophic conditions exhibit plastids which undergo cyclic morphological transformations along a growth cycle. Ultrastructural studies show that the green chloroplasts present at the initial stage differentiate into amyloplasts during the subsequent log phase and then return to chloroplasts in stationary phase. The changes of the levels of plastid DNA (pt DNA) per cell have been determined along the growth cycle, as a percentage of total DNA by hybridization of definite amounts of total DNA to a radioactive probe of cloned pt DNA. The number of pt DNA copies have been estimated to 1125 per cell at the maximum of amyloplast development and to 5940 copies per cell at the maximum of chloroplast differentiation. Hybridizations of defined amounts of total cellular RNA to labelled probes of the 16S rDNA and of the rbcL gene allowed estimations of the variations of the corresponding cellular RNA pools. These variations are well correlated with the changes of the ptDNA cellular levels. These results show that the ptDNA gene dosage plays a central role in the regulation of the plastid transcript levels in this system.