Removal of grade IV vestibular schwannomas by retrosigmoid approach: results of a cumulative series of two European centers.

INTRODUCTION: The aim of our study was to study the association between end-of-surgery facial nerve stimulation threshold and extent of tumor resection in case of grade IV vestibular schwannomas. MATERIALS AND METHODS: Grade IV VSs represent a surgical challenge as a risk/benefit ratio must be considered in balancing a satisfactory extent of resection against a good postoperative functional outcome. We reviewed a cumulative series of 57 patients with large/giant VSs who were operated on by retrosigmoid approach in the period from 2008 to 2018 in two European centers, namely San Filippo Neri Hospital, Rome, Italy and Masaryk Hospital, Usti nad Labem, Czech Republic. Extent of resection, intraoperative direct electrical stimulation threshold of facial nerve and postoperative facial outcome were examined. RESULTS: Total or near-total resection was accomplished in 40 (75.5%) cases. Two groups were compared: total or near-total resection (T + NT) and subtotal resection (ST); the end-of-surgery facial nerve stimulation threshold significantly differed (T + NT: 0.24 mA, ST: 0.44 mA, p = 0.036). A critical cutoff was found at 0.2mA; values similar or inferior to this correctly predicted total or near-total resection in 86.7% of cases. Thirty (56.6%) patients had a normal postoperative facial outcome (HB1). Among the 40 patients in T + NT group, 32 (80%) retained an acceptable facial function (HB1-2). CONCLUSIONS: Lower facial nerve stimulation thresholds positively predict a broader extent of resection and total or -near total resection should be accomplished in such cases. Judicious (subtotal) resection is preferred if threshold values increase while dissecting firmly adherent tumors.

Acute Progressive Pediatric Post-Traumatic Kyphotic Deformity.

Cervical kyphosis is a rare entity with challenging management due to the limitations of pediatric age, along with a growing spine. The pathogenesis is made up of a large group of congenital, syndromic and acquired deformities after posterior element deterioration or as a result of previous trauma or surgery. In rare progressive cases, kyphotic deformities may result in severe "chin-on-chest" deformities with severe limitations. The pathogenesis of progression to severe kyphotic deformity after minor hyperflexion trauma is not clear without an obvious MR pathology; it is most likely multifactorial. The authors present the case of a six-month progression of a pediatric cervical kyphotic deformity caused by a cervical spine hyperflexion injury, and an MR evaluation without the pathology of disc or major ligaments. Surgical therapy with a posterior fixation and fusion, together with the preservation of the anterior growing zones of the cervical spine, are potentially beneficial strategies to achieve an excellent curve correction and an optimal long-term clinical outcome in this age group.

Dynamics of atlantoaxial rotation related to age and sex: a cross-sectional study of 308 subjects.

BACKGROUND CONTEXT: Physiological ranges and dynamic changes of atlantoaxial rotation (ROTC1/2), total cervical spine rotation (ROTCs) and the percentage of ROTC1/2 from ROTCs (ROTCperc) for different age groups have not yet been investigated in a sufficiently sized cohort. Furthermore, it is not clear whether demographic variables such a sex, smoking status or diabetes affect ROTC1/2, ROTCs and ROTCperc. PURPOSE: Obtain physiological ranges of ROTC1/2, ROTCs and ROTCperc for different age groups and determine their age-based dynamics. Investigate whether ROTC1/2, ROTCs and ROTCperc are affected by sex, smoking status or diabetes. DESIGN: Observational cross-sectional study. PATIENT SAMPLE: Patients undergoing elective CT examinations of the head and neck region between August 2020 and January 2022. OUTCOME MEASURES: Ranges of motion of ROTC1/2, ROTCs and ROTCperc in degrees. METHODS: A total of 308 subjects underwent dynamic rotational CT examinations of the upper cervical spine. Patients were divided into three age categories A1 (27-49 years), A2 (50-69 years) and A3 (≥70 years). Category A3 was further divided into B1 (70-79 years) and B2 (≥80 years). Values of ROTC1/2, ROTCs and ROTCperc were compared between all age groups, males and females, smokers and nonsmokers, diabetics a nondiabetics. Dynamics of ROTC1/2, ROTCs related to age and sex were visualized using scatterplot and trendline models. RESULTS: ROTC1/2 significantly decreased from group A1 (64.4°) to B2 (46.7°) as did ROTCs from A1 (131.2°) to B2 (97.6°). No significant differences of ROTperc were found between groups A1-B2 with values oscillating between 49% and 51%. Smoking and diabetes did not significantly affect ROTC1/2, ROTCs and ROTCperc, females had significantly higher ROTCs than males. Males and females demonstrated a different dynamic of ROTC1/2 and ROTCs demonstrated by out scatterplot and trendline models. CONCLUSIONS: Both ROTC1/2 and ROTCs significantly decrease with age, whereas ROTCperc remains stable. Females demonstrated higher ROTCs and their decrease of ROTC1/2 and ROTCs occurred in higher age groups compared to males. The functional repercussions atlantoaxial fusion are variable based on patient age and sex and should be taken into account prior to surgery.

Cauda equina neuroendocrine tumors show biological features distinct from other paragangliomas and visceral neuroendocrine tumors.

Cauda equina neuroendocrine tumors (CENETs) are neoplasms of uncertain histogenesis with overlapping features between those of paragangliomas (PGs) and visceral neuroendocrine tumors (NETs). We have explored their biological relationship to both subsets of neuroendocrine neoplasms. The clinical and radiological features of a cohort of 23 CENETs were analyzed. A total of 21 cases were included in tissue microarrays, along with a control group of 38 PGs and 83 NETs. An extensive panel of antibodies was used to assess epithelial phenotype (cytokeratins, E-cadherin, EpCAM, Claudin-4, EMA, CD138), neuronal and neuroendocrine features (synaptophysin, chromogranin A, INSM1, neurofilaments, NeuN, internexin-α, calretinin), chromaffin differentiation (GATA3, Phox2b, tyrosine hydroxylase), and possible histogenesis (Sox2, T-brachyury, Oct3/4, Sox10). The cohort included 5 women (22%) and 18 men (78%). The average age at the time of surgery was 48.3 years (range from 21 to 80 years). The average diameter of the tumors was 39.27 mm, and invasion of surrounding structures was observed in 6/21 (29%) tumors. Follow-up was available in 16 patients (median 46.5 months). One tumor recurred after 19 months. No metastatic behavior and no endocrine activity were observed. Compared to control groups, CENETs lacked expression of epithelial adhesion molecules (EpCAM, CD138, E-cadherin, Claudin-4), and at the same time, they lacked features of chromaffin differentiation (GATA3, Phox2b, tyrosine hydroxylase). We observed no loss of SDHB. Cytokeratin expression was present in all CENETs. All the CENETs showed variable cytoplasmic expression of T-brachyury and limited nuclear expression of Sox2. These findings support the unique nature of the neoplasm with respect to NETs and PGs.

Utility of Hounsfield units in predicting fusion rates of patients undergoing anterior odontoid screw fixation following Anderson d'Alonzo type II and shallow type III fractures.

BACKGROUND: Main objective of this study was to determine whether Hounsfield units (HU) measured in three areas of the axis correlate with successful fusion in patients with type II and shallow type III C2 fractures undergoing anterior odontoid screw osteosynthesis (AOSF). METHODS: Forty-five patients with C2 fractures treated via AOSF were analyzed. Only bony fusion with bone trabeculations across the fracture line was considered a successful result. Preoperative HU values were measured in three zones- corpus, watershed and dens. Statistical analysis was performed to determine significant differences between HU of fused and unfused patients in all three zones of a complete and adjusted patient cohort. RESULTS: Statistically significant differences of HU values were found between fused (corpus- 363.7, watershed- 327.9) and unfused (corpus- 279.5, watershed- 194.2) of the complete cohort and the adjusted cohort. Cut-off HU values in the watershed zone were calculated for the complete (250 and 300) and adjusted cohort (240 and 260), dividing patients into three groups of bone quality. Patients with high watershed bone quality (HU>300) achieved successful fusion in 84.62%, patients with low bone quality (HU<250) in 3.85% and patients with medium bone quality (HU 250-300) in 50%. CONCLUSIONS: Preoperative measurement of HU can be used to predict the probability of successful fusion in patients undergoing AOSF for type II and shallow type III C2 fractures. AOSF is a highly effective treatment modality in patients with watershed HU>300, whereas alternatives should be considered in patients with watershed HU<250.

Intraoperative Measurement of Endotracheal Tube Cuff Pressure and Its Change During Surgery in Correlation With Recurrent Laryngeal Nerve Palsies, Hoarseness, and Dysphagia After Anterior Cervical Discectomy and Fusion: A Prospective Randomized Controlled Trial.

STUDY DESIGN: Prospective randomized controlled trial. OBJECTIVES: Adjustment of endotracheal tube cuff pressure (ETCP) in anterior cervical discectomy and fusion (ACDF) may influence the incidence of complications such as recurrent laryngeal nerve palsy (RLNP), hoarseness, and dysphagia. METHODS: The prospective randomized controlled trial was designed to investigate the influence of ETCP on the incidence of postoperative complications. All eligible patients underwent vocal cord examination before and after ACDF and were randomized into a control group (CG) and intervention group (IG). Endotracheal tube cuff pressure was passively monitored in CG, and in IG, it was maintained at 20 mmHg. Outcomes were evaluated during hospitalization and during follow-up. RESULTS: A total of 98 patients were randomized, each group consisted of 49 patients. Statistical analysis showed that gender and age did not influence the incidence of complications. In CG, duration of retractor placement and extent of approach significantly impacted the occurrence of complications. The incidence of postoperative RLNP was 8.2% in IG and 12.2% in CG, hoarseness and dysphonia were present in 18.4% in IG and in 37.5% in CG, and dysphagia in 20.8% in IG and in 22.5% in CG. Hoarseness was significantly present more in CG (P = .018). Only one patient from CG presented with RLNP after 1 year, the remaining nine patients spontaneously recovered. CONCLUSIONS: Unregulated ETCP can lead to a significantly higher incidence of hoarseness; however, its improvement rate is 100%. The early postoperative complication rate was higher in CG, and after one year, 1 patient had RLNP and 1 patient had dysphagia.

Quantitative gait analysis of patients with severe sacroiliac joint dysfunction: a prospective clinical study.

BACKGROUND: Sacroiliac joint (SIJ) dysfunction is a chronic painful condition responsible for up to 30% of back pain. Treatment modalities include physiotherapy, intraarticular analgesic injections, ablation techniques or SIJ fusion. The severity of SIJ dysfunction is commonly assessed via subjective pain or disability scales. Quantitative gait analysis offers an objective means of evaluating patients with SIJ dysfunction prior to its surgical treatment. METHODS: Ten patients diagnosed with severe SIJ dysfunction were matched with 10 healthy controls. All individuals underwent quantitative 3D gait analysis using the Qualisys program and statistical analysis was performed to identify significant differences in gait parameters between the two groups. RESULTS: Two groups of data were obtained; angular parameters described by the Gait Profile Score (GPS) and spatiotemporal parameters described in standard SI units. Statistically significant differences were found between the patient and control group for parameters: overall GPS (P=0.049), hip abduction/adduction (P=0.017) and ankle plantar/dorsal flexion (P=0.003), stride length (P=0.002), step length (P=0.001), swing time (P=0.03) and initial double limb support (P=0.02). CONCLUSIONS: This paper is the first to perform complex quantitative gait analysis of patients with SIJ dysfunction and to compare it with healthy individuals. These results can provide clinicians with baseline gait values for these patients to objectively quantify the extent of their disease.

Basic Analysis of the Cerebrospinal Fluid: An Important Framework for Laboratory Diagnostics of the Impairment of the Central Nervous System.

Laboratory analysis of basic cerebrospinal fluid (CSF) parameters is considered as essential for any CSF evaluation. It can provide rapidly very valuable information about the status of the central nervous system (CNS). Our retrospective study evaluated parameters of basic CSF analysis in cases of either infectious or non-infectious CNS involvement. Neutrophils are effector cells of innate immunity. Predominance of neutrophils was found in 98.2% of patients with purulent inflammation in CNS. Lymphocytes are cellular substrate of adaptive immunity. We found their predominance in 94.8% of patients with multiple sclerosis (MS), 66.7% of patients with tick-borne encephalitis (TBE), 92.2% of patients with neuroborreliosis, 83.3% of patients with inflammatory response with oxidative burst of macrophages in CNS and 75.0% of patients with malignant infiltration of meninges (MIM). The simultaneous assessment of aerobic and anaerobic metabolism in CSF using the coefficient of energy balance (KEB) allows us to specify the type of inflammation in CNS. We found predominantly aerobic metabolism (KEB > 28.0) in 100.0% CSF of patients with normal CSF findings and in 92.8% CSF of patients with MS. Predominant faintly anaerobic metabolism (28.0 > KEB > 20.0) in CSF was found in 71.8% patients with TBE and in 64.7% patients with neuroborreliosis. Strong anaerobic metabolism (KEB < 10.0) was found in the CSF of 99.1% patients with purulent inflammation, 100.0% patients with inflammatory response with oxidative burst of macrophages and in 80.6% patients with MIM. Joint evaluation of basic CSF parameters provides sufficient information about the immune response in the CSF compartment for rapid and reliable diagnosis of CNS involvement.

Quantitative Gait Analysis of Patients with Severe Symptomatic Spinal Stenosis Utilizing the Gait Profile Score: An Observational Clinical Study.

Lumbar spine stenosis (LSS) typically manifests with neurogenic claudication, altering patients' gait. The use of optoelectronic systems has allowed clinicians to perform 3D quantitative gait analysis to quantify and understand these alterations. Although several authors have presented analysis of spatiotemporal gait parameters, data concerning kinematic parameters is lacking. Fifteen patients with LSS were matched with 15 healthy controls. Quantitative gait analysis utilizing optoelectronic techniques was performed for each pair of subjects in a specialized laboratory. Statistical comparison of patients and controls was performed to determine differences in spatiotemporal parameters and the Gait Profile Score (GPS). Statistically significant differences were found between patient and control groups for all spatiotemporal parameters. Patients had significantly different overall GPS (p = 0.004) and had limited internal/external pelvic rotation (p < 0.001) and cranial/caudal movement (p = 0.034), limited hip extension (p = 0.012) and abduction/adduction (p = 0.012) and limited ankle plantar flexion (p < 0.001). In conclusion, patients with LSS have significantly altered gait patterns in three regions (pelvis, hip and ankle) compared to healthy controls. Analysis of kinematic graphs has given insight into gait pathophysiology of patients with LSS and the use of GPS will allow us to quantify surgical results in the future.

Neutrophils in Extravascular Body Fluids: Cytological-Energy Analysis Enables Rapid, Reliable and Inexpensive Detection of Purulent Inflammation and Tissue Damage.

The simultaneous cytological and metabolic investigation of various extravascular body fluids (EBFs) provides clinically relevant information about the type and intensity of the immune response in particular organ systems. The oxidative burst of professional phagocytes with the concomitant production of reactive oxygen species consumes a large amount of oxygen and is the cause of switch to the development of anaerobic metabolism. We assessed the relationships between percentages of neutrophils, aerobic and anaerobic metabolism, and tissue damage via the determination of aspartate aminotransferase catalytic activities (AST) in cerebrospinal fluid (CSF), pleural effusions (PE), abdominal effusions (AE), and synovial fluids (SF). EBFs with 0.0-20.0% neutrophils: 83.0% aerobic and 1.3% strongly anaerobic cases with median of AST = 13.8 IU/L in CSF; 68.0% aerobic and 9.0% strongly anaerobic cases with median of AST = 20.4 IU/L in PE; 77.5% aerobic and 10.5% strongly anaerobic cases with median of AST = 18.0 IU/L in AE; 64.1% aerobic and 7.7% strongly anaerobic cases with median of AST = 13.8 IU/L in SF. EBFs with 80.0-100.0% neutrophils: 4.2% aerobic and 73.7% strongly anaerobic cases with median of AST = 19.2 IU/L in CSF; 7.4% aerobic and 77.3% strongly anaerobic cases with median of AST = 145.2 IU/L in PE; 11.8% aerobic and 73.7% strongly anaerobic cases with median of AST = 61.8 IU/L in AE; 25.5% aerobic and 38.2% strongly anaerobic cases with median of AST = 37.2 IU/L in SF. The significant presence of neutrophils, concomitant strong anaerobic metabolism, and elevated AST in various EBFs are reliable signs of damaging purulent inflammation.

Development of the Cerebrospinal Fluid in Early Stage after Hemorrhage in the Central Nervous System.

Extravasation of blood in the central nervous system (CNS) represents a very strong damaged associated molecular patterns (DAMP) which is followed by rapid inflammation and can participate in worse outcome of patients. We analyzed cerebrospinal fluid (CSF) from 139 patients after the CNS hemorrhage. We compared 109 survivors (Glasgow Outcome Score (GOS) 5-3) and 30 patients with poor outcomes (GOS 2-1). Statistical evaluations were performed using the Wilcoxon signed-rank test and the Mann-Whitney U test. Almost the same numbers of erythrocytes in both subgroups appeared in days 0-3 (p = 0.927) and a significant increase in patients with GOS 2-1 in days 7-10 after the hemorrhage (p = 0.004) revealed persistence of extravascular blood in the CNS as an adverse factor. We assess 43.3% of patients with GOS 2-1 and only 27.5% of patients with GOS 5-3 with low values of the coefficient of energy balance (KEB < 15.0) in days 0-3 after the hemorrhage as a trend to immediate intensive inflammation in the CNS of patients with poor outcomes. We consider significantly higher concentration of total protein of patients with GOS 2-1 in days 0-3 after hemorrhage (p = 0.008) as the evidence of immediate simultaneously manifested intensive inflammation, swelling of the brain and elevation of intracranial pressure.

Delayed Ischemic Neurological Deficit after Uneventful Elective Clipping of Unruptured Intracranial Aneurysms.

Cerebral vasospasm and subsequent delayed ischemic neurological deficit is a typical sequela of acute subarachnoid hemorrhage after aneurysm rupture. The occurrence of vasospasms after uncomplicated surgery of an unruptured aneurysm without history of suspected rupture is extremely rare. The pathogenesis and severity of cerebral vasospasms is typically correlated with the amount of blood breakdown products extravasated during subarachnoid hemorrhage. In rare cases, where vasospasms occur after unruptured aneurysm surgery, the pathogenesis is most likely multifactorial and unclear. We present two cases of vasospasms following uncomplicated clipping of middle cerebral artery (MCA) aneurysms and a review of literature. Early diagnosis and therapy of this rare complication are necessary to achieve optimal clinical outcomes.

Masseteric nerve supercharge bypass in primary reconstruction of facial nerve.

Facial paralysis is a severe disease and presents a formidable treatment challenge. A wide variety of surgical procedures are available with limited evidence. Major risk factors of suboptimal recovery include the duration of paralysis as well as higher age. In this paper, we demonstrate reconstruction of the facial nerve via an intratemporal end-to-end anastomosis and concomitant transfer of an intact masseteric nerve to the side of facial nerve trunk. The supercharge (reverse end-to-side) transfer resulted in preservation of target muscles and faster recovery. Masseteric supercharge bypass may be an acceptable surgical technique to restore muscle function in potentially higher risk cases.

Anesthesia type determines risk of cerebral infarction after carotid endarterectomy.

OBJECTIVE: Silent and symptomatic cerebral infarctions occur in up to 34% of patients after carotid endarterectomy (CEA). This prospective study compared the risk of new brain infarctions detected by magnetic resonance imaging (MRI) in patients with internal carotid artery stenosis undergoing CEA with local anesthesia (LA) vs general anesthesia (GA). METHODS: Consecutive patients with internal carotid artery stenosis indicated for CEA were screened at two centers. Patients without contraindication to LA or GA were randomly allocated to the LA or GA group by ZIP code randomization. Brain MRI was performed before and 24 hours after CEA. Neurologic examination was performed before and 24 hours and 30 days after surgery. The occurrence of new infarctions on the control magnetic resonance images, stroke, transient ischemic attack, and other complications was statistically evaluated. RESULTS: Of 210 randomized patients, 105 underwent CEA with LA (67 men; mean age, 68.3 ± 8.1 years) and 105 with GA (70 men; mean age, 63.4 ± 7.5 years). New infarctions were more frequently detected on control magnetic resonance images in patients after CEA under GA compared with LA (17.1% vs 6.7%; P = .031). Stroke or transient ischemic attack occurred within 30 days of CEA in three patients under GA and in two under LA (P = 1.000). There were no significant differences between the two types of anesthesia in terms of the occurrence of other complications (14.3% for GA and 21.0% for LA; P = .277). CONCLUSIONS: The risk of silent brain infarction after CEA as detected by MRI is higher under GA than under LA.

Cerebrospinal Fluid Rhinorrhea due to Transethmoidal Encephalocele Following Occipital Meningioma Resection in an Adult: A Case Report.

Transethmoidal encephalocele is a rare condition in adult patients. It is usually diagnosed during childhood by cerebrospinal fluid (CSF) rhinorrhea, meningitis, a nasal mass, or seizures. We present a case of an adult woman with CSF rhinorrhea following resection of an occipital meningioma. The cribriform plate defect containing the encephalocele was diagnosed by computed tomography and magnetic resonance imaging. Transcranial surgery using a patch was performed successfully. We also discuss the possible pathophysiologic mechanisms of encephalocele and treatment options.

Chemical angioplasty with spasmolytics for vasospasm after subarachnoid hemorrhage.

BACKGROUND: Clinically symptomatic vasospasm leading to delayed ischemic neurological deficits occurs in up to 30% of patients with subarachnoid hemorrhage (SAH). Vasospasm can result in a serious decline in clinical conditions of patients with SAH, yet the algorithm for vasospasm treatment and prevention remains unclear. Intra-arterial administration of vasodilators is one of the modalities used for vasospasm therapy. METHODS: Over the last 7 years, we have treated 27 female and 7 male patients with vasospasm using intra-arterial administration of either nimodipine or milrinone; all had suffered aneurysm rupture. Of these patients, 28 were treated surgically (clip), and 6 patients had their aneurysm coiled. Spasmolytics were applied from day 2 to day 18 after rupture. RESULTS: Of the 53 procedures, angiographic improvement was documented in 92% of cases with a mean flow velocity decrease of 65 cm/s. Brain metabolism changes were monitored after the procedure. The highest level of immediate clinical improvement was observed in conscious patients with a focal neurological deficit (aphasia, hemiparesis). Overall clinical outcomes (Glasgow outcome scale, GOS) were as follows: GOS 5 (12 patients), GOS 4 (5 patients), GOS 3 (5 patients), GOS 2 (6 patients), and GOS 1 (6 patients). CONCLUSIONS: Intra-arterial administration of spasmolytics is a safe and potent method of vasospasm treatment. It is most effective when applied to conscious patients with a focal deficit. For unconscious patients, its therapeutic benefits are inconclusive. Patients in severe clinical states would further require use of other diagnostic tools such as multimodal brain monitoring to complement vasospasm therapy.

Carotid-ophthalmic aneurysms-Our results and treatment strategy.

OBJECTIVE: Ophthalmic aneurysms comprise 1.3-5% of all intracranial aneurysms and are the least likely to rupture. On the other hand, they can cause symptoms (visual dysfunction and eye movement palsy) in 18-35% of cases even when unruptured. In our article, we review all the cases of ophthalmic aneurysms treated in our department, discuss treatment methods, and compare our results with those reported in the literature. MATERIAL AND METHODS: In the period 1998-2010, we operated on 37 patients and treated 21 endovascularly. Out of these surgically/endovascularly treated, there were 11/7 asymptomatic, 3/2 unruptured symptomatic, and 23/12 ruptured casess. RESULTS: Surgically treated: Asymptomatic aneurysms were operated on with 9% (1 patient) mortality (due to delayed infection); 87% of patients with ruptured aneurysms improved, 9% remained unchanged, and 4% got worse. Visual dysfunction was restored in 66% of unruptured symptomatic cases (2 patients operated on within 1 month of the start of symptoms). Endovascularly treated. Asymptomatic aneurysms were coiled with 9% (1 patient) mortality and 9% (1 patient) morbidity. Patients with ruptured aneurysms improved in 50% of cases, 25% of patients did not change, 1 patient got worse (12.5%), and 1 patient died (12.5%). Only 1 of 3 coiled patients showed improved 3rd nerve palsy after coiling of an unruptured aneurysm. CONCLUSION: The mortality and morbidity of aneurysms treated in our department, both unruptured and ruptured, were relatively low and comparable with the results presented in the literature. The number of unruptured aneurysms with visual dysfunction was not as high as reported in the literature, but our results correlate with the main conclusion of those studies: to treat those aneurysms surgically when possible and within three months from the start of symptoms.

A selective carotid artery shunting for carotid endarterectomy: prospective MR DWI monitoring of embolization in a group of 754 patients.

BACKGROUND: Intraoperative use of the intraluminal shunt may reduce the risk of a stroke by reducing cerebral blood flow compromise, but it may also increase the risk of atherosclerotic arterial wall damage with subsequent stroke during carotid endarterectomy (CEA). There is still no evidence to support routine or selective shunting. MATERIAL AND METHODS: A total of 754 CEAs were performed in a prospective study from 2005 to 2011 at our department. All procedures were done under regional anesthesia with selective carotid artery shunting according to neurologic status after internal carotid artery clamping. Magnetic resonance (MR) evaluation of brain parenchyma using diffusion-weighed imaging (DWI) sequence was performed upon hospital admission and 24 hours after the surgical procedure. Acute new MR DWI lesions were evaluated according to the classification published by Szabo et al. A routine neurologic evaluation was recorded as well. RESULTS: The intraluminal shunt was used in 46 of 754 patients (6.1%). A new ischemic lesion was detected in 45 patients (6%). Most of these lesions were neurologically asymptomatic (80%). A new lesion on MR DWI in the subgroup of shunted patients was detected in 15 cases (32.6%) and in the subgroup of nonshunted patients in 30 cases (4.2%). Most of these lesions were due to embolization or hypoperfusion during shunt insertion. CONCLUSION: Use of the intraluminal shunt was the most important risk factor for the new MR DWI lesion in the entire group of CEAs. Results support the strategy of a selective use of intraluminal shunts.

Distant white-matter diffusion changes caused by tumor growth.

OBJECTIVES: Various reports have suggested that the involvement of normal-looking white matter with tumors is not limited to just signal abnormalities detectable on conventional imaging. Thus, the purpose of this study was to investigate the distant effects of glioblastomas and metastases on white matter using diffusion tensor imaging (DTI). MATERIALS AND METHODS: Data for 21 patients harboring a glioblastoma (n=12) or a metastasis (n=9) located at a distance of smaller or equal to 10mm from a DTI-based reconstruction of the pyramidal tract were analyzed, using regions of interest (ROIs) placed along the pyramidal tracts in the cerebral peduncle distant (>15 mm) from the tumor. RESULTS: For the whole study population, fractional anisotropy (FA) was significantly lower on the side ipsilateral to the tumor (P<0.001), a difference that was also observed in the glioblastoma and metastasis subgroups. The trace value was significantly higher on the ipsilateral side in the whole population and metastasis subgroup, but not in the glioblastoma subgroup. The decrease in FA and the trace value increase were significant in a subgroup of patients with motor deficits, but not in those without such deficits. CONCLUSION: Hemispheric glioblastomas and metastases located close to the pyramidal tract induce diffusion changes in the tract that are observable at a distance of greater than 15 mm from the tumor border in the absence of T2 signal changes. These changes are different in glioblastomas and metastases, and mechanisms other than Wallerian degeneration may be contributing to the observed changes.

Anatomy of the supraventricular portion of the pyramidal tract.

BACKGROUND: The anatomy and somatotopy of the pyramidal tract during its course in the internal capsule has recently been discussed by many publications. However, the reports on the anatomy of the clinically more important supraventricular portion of the tract are scarce. The objective of this study is to investigate the anatomy and somatotopy of the supraventricular portion of the pyramidal tract. METHODS: In 13 patients undergoing surgery with subcortical electric stimulation for tumors located in the supraventricular white matter close to the pyramidal tract (as depicted by diffusion tensor tracking [DTT]), the relationship between the position of the stimulation point and the motor response in the arm or leg was analyzed. Additionally, the somatotopic organization of the tract was studied using separate tracking of arm and leg fibers in 20 healthy hemispheres. Finally, the course of the tract was studied by dissecting 15 previously frozen human hemispheres. RESULTS: In most cases, subcortical stimulation during the resection of tumors located behind and in front of the pyramidal tract elicited leg and arm movement, respectively. This association of stimulation point position with motor response type was significant. A DTT study of the somatotopy demonstrated a varying degree of rotation of the leg and arm fibers from mediolateral to posteroanterior configuration. Anatomic dissections demonstrated a folding-fan like structure of the pyramidal tract with a similar rotation pattern. CONCLUSION: The pyramidal tract undergoes a large part of its rotation from mediolateral to posteroanterior configuration during its course in the supraventricular white matter, although interindividual differences exist.