Michel W. Bojanowski

Scalp nerve blocks decrease the severity of pain after craniotomy

Up to 80% of patients report moderate to severe pain after craniotomy. In this study, we assessed the efficacy of scalp block for decreasing postoperative pain in brain surgery. Thirty patients scheduled for supratentorial craniotomy were enrolled. They were randomly divided into two groups: Ropivacaine (scalp block with 20 mL of ropivacaine 0.75%) and Saline (scalp block with 20 mL of saline 0.9%). Anesthesia was standardized. The scalp block was performed after skin closure and before awakening. Postoperative pain was assessed at 4, 8, 12, 16, 20, 24, and 48 h by using a 10-cm visual analog scale. Analgesia was provided with sub- cutaneous codeine as requested by the patient. Average visual analog scale scores were higher in the Saline group as compared with Ropivacaine (3.7 ± 2.4 vs 2.0 ± 1.6;P = 0.036). The total dose of codeine did not differ, nor did the duration of time before the first dose of codeine was required in the Ropivacaine (571 ± 765 min) versus Saline (319 ± 409 min;P = 0.17) group. In conclusion, we found that postoperative scalp block decreases the severity of pain after craniotomy and that this effect is long lasting, possibly through a preemptive mechanism.

Knock-out of the cyaY gene in Escherichia coli does not affect cellular iron content and sensitivity to oxidants.

Friedreich ataxia is a recessively inherited neurodegenerative disease caused by deficiency of a highly conserved mitochondrial protein, frataxin. Frataxin deficiency results in mitochondrial iron accumulation and oxidative stress. Frataxin shows homology with the CyaY proteins of γ‐purple bacteria, whose function is unknown. We knocked out the CyaY gene in Escherichia coli MM383 by homologous recombination and we generated an E. coli MM383 strain overexpressing CyaY. Bacterial growth, iron content and survival after exposure to H2O2 did not differ among these strains, suggesting that, despite structural similarities, cyaY proteins in bacteria may have a different function from frataxin homologues in mitochondria.

Surgical Management of Blood Blister–like Aneurysms of the Internal Carotid Artery

OBJECTIVE To present a review of the literature and a case series of blood blister-like aneurysms (BBA) to show that an adapted direct surgical approach enables treatment of BBA with a low complication rate. METHODS A retrospective review was performed of patients treated for a ruptured BBA of the internal carotid artery (ICA) at Hôpital Notre-Dame from 2005-2009. Clinicoradiologic data and intraoperative videos were analyzed. Outcome was assessed using the modified Rankin scale (mRS). RESULTS This series includes 7 patients (4 women and 3 men) with a mean age of 44.7 (range 30-61). All patients presented with subarachnoid hemorrhage (SAH). Four angiograms were initially negative. Diameter of BBA ranged from 1.1-8.2 mm. No intraoperative or postoperative aneurysm rupture occurred in this series. Although angiograms showed expected mild stenosis of the ICA after clipping, no clinical or radiologic cerebral infarctions were observed. The outcome was favorable in all patients. CONCLUSIONS Recognition of BBA is essential for proper management. An appropriate neurosurgical strategy has enabled a significant reduction in perioperative aneurysm rupture compared with previous reports and obtains excellent functional results.

Decompressive craniectomy is not an independent risk factor for communicating hydrocephalus in patients with increased intracranial pressure.

BACKGROUNDIt was recently suggested that communicating hydrocephalus is an almost universal finding after hemicraniectomy and that early cranioplasty may prevent the need for permanent cerebrospinal fluid diversion in these patients. OBJECTIVETo conduct a study in an attempt to verify these findings. METHODSThe medical records of all patients who underwent decompressive craniectomy for medically refractory elevated intracranial pressure between 2001 and 2009 were retrospectively reviewed. Patients with subarachnoid hemorrhage, intraventricular hemorrhage, or head trauma were excluded. Hydrocephalus was classified as internal or external and as clinically significant or asymptomatic. RESULTSThe patient population consisted of 17 patients, 8 men and 9 women, with a median age of 44 years (range, 27–53 years). Etiologies included malignant middle cerebral artery territory infarction in 12 patients, hemorrhagic transformation of ischemic cerebrovascular accident in 2 patients, dural sinus thrombosis in 2 patients, and hemorrhagic cerebrovascular accident in 1 patient. The extent of craniectomy ranged from a large bone flap in 4 patients to a standard hemicraniectomy in 13 patients. Two patients died and 1 was lost to follow-up during the acute stage. The remaining 14 patients underwent cranioplasty after a median interval of 21 days (range, 3–42 days). In none of these patients did clinically significant hydrocephalus develop requiring cerebrospinal fluid diversion. Asymptomatic extra-axial cerebrospinal fluid collections developed in 2 patients that resolved spontaneously after cranioplasty. CONCLUSIONOur results suggest that, contrary to some beliefs, hydrocephalus does not frequently occur after decompressive craniectomy.

Quality of Life Following Hemicraniectomy for Malignant MCA Territory Infarction

OBJECTIVE Decompressive hemicraniectomy (DH) has been shown to reduce mortality in patients with malignant middle cerebral artery (MCA) territory infarction. However, many patients survive with moderate-to-severe disability and controversy exists as to whether this should be considered good outcome. To answer this question, we assessed the quality of life (QoL) of patients after DH for malignant MCA territory infarction in our milieu. METHODS The outcome of all patients undergoing DH for malignant MCAterritory infarction between 2001 and 2009 was assessed using retrospective chart analysis and telephone follow-up in survivors. Functional outcome was determined using Glasgow outcome scale, modifed Rankin scale (mRS), and Barthel index (BI). The stroke impact scale was used to assess QoL. RESULTS There were 14 patients, 6 men and 8 women, with a mean age of 44 years (range 27-57). All patients had reduced level of consciousness preoperatively. Five had dominant-hemisphere stroke. Median time to surgery was 45 hours (range 1- 96). Two patients died and one was lost to follow-up. Of 11 survivors, 7 (63.6%) had a favorable functional outcome (mRS<4). No patient was in persistent vegetative state. Despite impaired QoL, particularly in physical domains, the majority of interviewed patients and caregivers (7 of 8), including those with dominant-hemisphere stroke, were satisfied after a median follow-up of 18 months (range 6-43). CONCLUSION Most patients report satisfactory QoL despite significant disability even in the face of moderate-to-severe disability and dominant-hemsiphere stroke. Dominant-hemisphere malignant MCA territory infarction should not be considered a contraindication to DH.

Pulmonary edema and cardiac dysfunction following subarachnoid hemorrhage

BACKGROUND Pulmonary edema (PE) can occur in the early or late period following subarachnoid hemorrhage (SAH). The incidence of each type of PE is unknown and the association with ventricular dysfunction, both systolic and diastolic, has not been described. METHODS Retrospective chart review of 178 consecutive patients with SAH surgically treated over a three-year period. Patients with pulmonary edema diagnosed by a radiologist were included. Early onset SAH was defined as occurring within 12 hours. Cardiac function at the time of the PE was analyzed using hemodynamic and echocardiographic criteria of systolic and diastolic dysfunction. Pulmonary edema was observed in 42 patients (28.8%) and was more often delayed (89.4%). Evidence of cardiac involvement during PE varied between 40 to 100%. RESULTS AND CONCLUSIONS Pulmonary edema occurs in 28.8% of patients after SAH, and is most commonly delayed. Cardiac dysfunction, both systolic and diastolic, is commonly observed during SAH and could contribute to the genesis of PE after SAH.

Brain endothelial cells as pharmacological targets in brain tumors

The blood-brain barrier contributes to brain homeostasis by controlling the access of nutrients and toxic substances to the central nervous system (CNS). The acquired brain endothelial cells phenotype results from their sustained interactions with their microenvironment. The endothelial component is involved in the development and progression of most CNS diseases such as brain tumors, Alzheimer’s disease, or stroke, for which efficient treatments remain to be discovered. The endothelium constitutes an attractive therapeutical target, particularly in the case of brain tumors, because of the high level of angiogenesis associated with this disease. Drug development based on targeting differential protein expression in the vasculature associated with normal tissues or with disease states holds great potential. This article highlights some of the growing body of evidence showing molecular differences between the vascular bed phenotype of normal and pathological endothelium, with a particular focus on brain tumor endothelium targets, which may play crucial roles in the development of brain cancers. Finally, an overview is presented of the emerging therapies for brain tumors that take the endothelial component into consideration.

Embolization as One Modality in a Combined Strategy for the Management of Cerebral Arteriovenous Malformations

We attempted to assess clinical results of management of cerebral arteriovenous malformation using a combination of endovascular, surgical and radiotherapeutic approaches. We retrospectively reviewed the angiographic and clinical data on prospectively collected consecutive patients treated by embolization from 1994 to 2004. The general philosophy was to attempt treatment by a combination of approaches only when an angiographic cure was likely or at least possible. The clinical outcome was assessed according to the modified Rankin scale. Although 404 patients were collected, complete files and follow-ups are available for 227 or 56% only. Most patients presented with hemorrhages (53%) or seizures (23%). The final management consisted in embolization alone in 34%, embolization followed by surgery in 47%, embolization and radiotherapy in 16%, and embolization, surgery and radiotherapy in 3% of patients. The embolization procedure itself could lead to an angiographic cure in only 16% of patients. When the management strategy could be completed, the cure rate increased to 66%. Complications of embolization occurred in 22.6% of patients. Overall clinical outcome was excellent (Rankin 0) in 43%, good (Rankin 1) in 38%, fair (Rankin 2) in 10%, poor (Rankin 3–5) in 2%, and the death rate was 7%. A combined strategy initially designed to provide angiographic cures cannot be completed in a significant number of patients; the total morbidity of treatment remains significant. There is no scientific evidence that cerebral arteriovenous malformations should be treated, and no clinical trial to prove that one approach is better than the other. Various treatment protocols have been proposed on empirical grounds. Small lesions can often be eradicated, with surgery when lesions are superficial, or with radiation therapy for deeper ones. There has been little controversy regarding therapeutic indications in these patients. The management of larger AVMs, sometimes in more eloquent locations, is much more difficult and controversial. Endovascular approaches have initially been developed to meet this challenge. It became quickly evident that embolization alone would rarely suffice to completely cure these lesions. The philosophy behind combined approaches is founded on 2 opinions: 1) There is no proven value of partial embolization, not even “partial benefits”, and treatment should aim at an angiographic cure and 2) By appropriately tailoring all available tools to each situation, such a cure could be reached with minimum or reasonable risks. We have used such a combined strategy for more than a decade now. Endovascular techniques and materials have evolved, and it is perhaps possible today to reach a cure by embolization alone in a larger proportion of patients than before. Aggressive embolizations, aiming for an endovascular cure, even sometimes in large lesions, have recently been promoted for their power or criticized for their risks. But before evaluating the advantages and inconveniences of new treatments, it may be wise to review the results we could achieve with a conventional approach combining endovascular, surgical and radiotherapeutic techniques.

Spinal man after declaration of brain death.

Complex spinal automatism in a patient who was declared brain dead is described. These movements tend to appear once cerebrospinal shock has abated. We postulate that these manifestations are a reflection of the physiological potential of the isolated spinal cord. These spinal movements should be included in the revised guidelines for the determination of cerebral death.

A comparison of two doses of mannitol on brain relaxation during supratentorial brain tumor craniotomy: a randomized trial.

BACKGROUND:Twenty percent mannitol is widely used to reduce brain bulk and facilitate the surgical approach in intracranial surgery. However, a dose-response relationship has not yet been established. In this study, we compared the effects of 0.7 and 1.4 g·kg−1 mannitol on brain relaxation during elective supratentorial brain tumor surgery. METHODS:In this prospective, randomized, double-blind study, we enrolled 80 patients undergoing supratentorial craniotomy for tumor resection. Patients were assigned to receive 0.7 g·kg−1 (group L) or 1.4 g·kg−1 (group H) of 20% mannitol at surgical incision. Brain relaxation was assessed immediately after opening of the dura on a scale ranging from 1 to 4 (1 = perfectly relaxed, 2 = satisfactorily relaxed, 3 = firm brain, 4 = bulging brain). RESULTS:There was no significant difference between the 2 groups regarding age, sex, body mass index, and brain tumor localization or size. In group L 52.5% of patients and in group H 77.5% of patients presented a midline shift (P = 0.03). The median scores of brain relaxation (interquantile range) were 2.0 (1.75–3) and 2.0 (1–3) (P = 0.16 for patients in group L and H, respectively). We then used a proportional odds model to adjust for this unbalanced distribution and to assess the group effect (low-dose versus high-dose mannitol) on brain relaxation scores. When adjusted for the presence of midline shift, the use of a higher dose of mannitol resulted in an odds ratio of 2.5 (P = 0.03). This indicates that, considering the effect of a midline shift, the odds of having a 1-level improvement in relaxation score in patients who received a higher dose of mannitol (group H) was 2.5 times as large as the odds for the low-dose group. The odds ratio of 0.29 (P = 0.007) for the midline shift indicates that its occurrence was associated with a higher probability of a lower relaxation score, on average. CONCLUSION:In this study, we show that 1.4 g·kg−1 of 20% mannitol results in equivalent brain relaxation scores as 0.7 g·kg−1 in patients undergoing craniotomy for supratentorial brain tumor. When corrected for the presence of midline shift, this study reveals that patients in the high-dose group had significantly more chances of obtaining a better relaxation score compared with the lower-dose group.