Consensus statement from the international consensus meeting on post-traumatic cranioplasty.

BACKGROUND: Due to the lack of high-quality evidence which has hindered the development of evidence-based guidelines, there is a need to provide general guidance on cranioplasty (CP) following traumatic brain injury (TBI), as well as identify areas of ongoing uncertainty via a consensus-based approach. METHODS: The international consensus meeting on post-traumatic CP was held during the International Conference on Recent Advances in Neurotraumatology (ICRAN), in Naples, Italy, in June 2018. This meeting was endorsed by the Neurotrauma Committee of the World Federation of Neurosurgical Societies (WFNS), the NIHR Global Health Research Group on Neurotrauma, and several other neurotrauma organizations. Discussions and voting were organized around 5 pre-specified themes: (1) indications and technique, (2) materials, (3) timing, (4) hydrocephalus, and (5) paediatric CP. RESULTS: The participants discussed published evidence on each topic and proposed consensus statements, which were subject to ratification using anonymous real-time voting. Statements required an agreement threshold of more than 70% for inclusion in the final recommendations. CONCLUSIONS: This document is the first set of practical consensus-based clinical recommendations on post-traumatic CP, focusing on timing, materials, complications, and surgical procedures. Future research directions are also presented.

Facial palsy caused by an intrameatal metastatic disease - Reconstruction with an autologous sural nerve graft.

Dysfunction of the facial nerve is frequently attributed to inflammation, followed by traumatic injury. Knowledge of the complex anatomical course of the facial nerve is critical to localize the site of pathology and for successful management. The multiplicity of etiologies and its complex anatomy often make facial paralysis a diagnostic challenge. Neoplasms are a fairly rare cause of peripheral facial palsy, and are frequently overlooked in search of the more frequent traumatic or inflammatory etiologies of facial paralysis. Isolated metastatic lesions to the cerebellopontine angle (CPA) and internal auditory canal (IAC) are extremely rare. Their accurate diagnosis is difficult, since they share common clinical and radiological characteristics with vestibular schwannomas. We report a case of a 63-year-old female with a rapidly progressive left-sided hearing loss and complete facial palsy. Magnetic resonance imaging revealed a left intrameatal lesion. A provisional diagnosis of intracanalicular schwannoma or meningioma was made, although the possibility of metastasis due to her rapid neurological deterioration was considered. The patient underwent a translabyrinthine complete removal of the tumor followed by facial nerve reconstruction. The final histopathological findings revealed a metastatic breast adenocarcinoma. To our knowledge only seven prior cases of an isolated metastatic CPA lesion have been reported. In patients without a known malignancy, a rapid progression of hearing loss, disequilibrium, and facial palsy might be the first sign of a metastatic CPA lesion.

Imaging biomarker analysis of advanced multiparametric MRI for glioma grading.

AIMS AND OBJECTIVES: To investigate the value of advanced multiparametric MR imaging biomarker analysis based on radiomic features and machine learning classification, in the non-invasive evaluation of tumor heterogeneity towards the differentiation of Low Grade vs. High Grade Gliomas. METHODS AND MATERIALS: Forty histologically confirmed glioma patients (20 LGG and 20 HGG) who underwent a standard 3T-MRI tumor protocol with conventional (T1 pre/post-contrast, T2-FSE, T2-FLAIR) and advanced techniques (Diffusion Tensor and Perfusion Imaging, 1H-MR Spectroscopy), were included. A semi-automated segmentation technique, based on T1W-C and DTI, was used for tumor core delineation in all available parametric maps. 3D Texture analysis considered 12 Histogram, 11 Co-Occurrence Matrix (GLCM) and 5 Run Length Matrix (GLRLM) features, derived from p, q, MD, FA, T1W-C, T2W-FSE, T2W-FLAIR and raw DSCE data. Along with 1H-MRS metabolic ratios and mean rCBV values, a total of 581 attributes for each subject were obtained. A Support Vector Machine - Recursive Feature Elimination (SVM-RFE) algorithm and SVM classifier were utilized for feature selection and classification, respectively. RESULTS: Three different SVM classifiers were evaluated with consecutively SVM-RFE feature subsets. Linear SMO classifier demonstrated the highest performance for determining the optimal feature subset. Finally, 21 SVM-RFE top-ranked features were adopted, for training and testing the SMO classifier with leave-one-out cross-validation, achieving 95.5% Accuracy, 95% Sensitivity, 96% Specificity and 95.5% Area Under ROC Curve. CONCLUSION: Results demonstrate that quantitative analysis of phenotypic characteristics, based on advanced multiparametric MR neuroimaging data and texture features, utilizing state-of-the-art radiomic analysis methods, can significantly contribute to the pre-treatment glioma grade differentiation.

Regional cerebral blood flow and cellular environment in subarachnoid hemorrhage: A thermal doppler flowmetry and microdialysis study.

BACKGROUND: Cerebral microdialysis enables assessment of regional metabolic physiology and provides biomarkers for clinical correlation in critical conditions, such as subarachnoid hemorrhage (SAH). The aim of our current study was to investigate the correlation between regional cerebral blood flow and microdialysis parameters (glucose, lactate, glycerol, pyruvate concentrations, and lactate/pyruvate metabolic ratio) in patients with SAH. MATERIALS AND METHODS: Twenty-one patients with SAH were enrolled in our retrospective study. Cerebral blood flow (CBF) based on thermal diffusion methodology, the thermal coefficient K, and microdialysis biochemical markers were recorded. The duration of the brain monitoring was 10 days. RESULTS: Microdialysis glucose concentration was inversely related to the cerebral temperature and to the L/P ratio. Furthermore, it was positively correlated to all other microdialysis parameters but glycerol. The K coefficient was strongly and positively correlated with the temperature and marginally with the CBF. The L/P ratio was positively correlated with glycerol, while it was inversely correlated with the CBF. Patients who died had elevated L/P ratio and K coefficient compared to the survivors in our series. CONCLUSIONS: Thermal conductivity coefficient may change over time as cerebral injury progresses and tissue properties alter. These alterations were found to be associated with the microdialysis metabolite concentrations and the CBF itself. The microdialysis biochemical indices of cell stress and death (glycerol, L/P ratio) were positively related to each other, while the measured L/P metabolic ratio was higher among patients who died.

Spectroscopic evaluation of glioma grading at 3T: the combined role of short and long TE.

PURPOSE: To evaluate the diagnostic value of 3T (1)H-MRS in grading cerebral gliomas using short and long echo times. METHODS: 1H-MRS was performed on 71 patients with untreated cerebral gliomas. Metabolite ratios of NAA/Cr, Cho/Cr, Cho/NAA, and mI/Cr were calculated for short and long TE and compared between low and high grade gliomas. Lipids were qualitatively evaluated. ROC analysis was performed to obtain the cut-off values for the metabolic ratios presenting statistical difference between the two glioma grades. RESULTS: Intratumoral Cho/Cr at both TEs and long TE Cho/NAA were significantly different between low and high grade gliomas. Peritumoral NAA/Cr of both TEs, as well as long TE Cho/Cr and Cho/NAA ratios, significantly differentiated the two tumor grades. Diagnostic sensitivity of peritumoral short TE NAA/Cr proved to be superior over the other metabolic ratios, whereas intratumoral short TE Cho/Cr reached the highest levels of specificity and accuracy. Overall, short TE 1H-MRS reached higher total sensitivity in predicting glioma grade, over long TE. CONCLUSION: An advantage was found in using short TE over long TE 1H-MRS in the discrimination of low versus high grade gliomas. Moreover, the results suggested that the peritumoral area of gliomas may be more valuable in predicting glioma grade than using only the intratumoral area.

Biochemical markers analyzed using microdialysis and traumatic brain injury outcomes.

AIM: Traumatic brain injury is a leading cause of disability and mortality among young people. Multiparametric cerebral bedside monitoring is a safe and promising technique for preventing secondary brain damage. The objective of this study was to investigate the usefulness of cerebral microdialysis in predicting the outcomes of patients with traumatic brain injury. METHODS: Thirty-eight patients (33 males) were included in the study. The GCS on admission was ≤8. The outcome was assessed using the GOS over six months of follow-up. RESULTS: Among the patients included, 18 had a favorable outcome (GOS=4.5) and the remaining 20 had an unfavorable outcome. L/P ratio and glycerol concentration were statistically significantly higher in the patients with unfavorable prognosis. CONCLUSION: Biochemical parameters analysed using microdialysis could serve as predictor indexes of clinical outcome several months after the injury.

The role of intraoperative micro-Doppler ultrasound in verifying proper clip placement in intracranial aneurysm surgery.

We present the results of a retrospective study employing intraoperative micro-Doppler ultrasonography (MDU) in verifying proper clip placement during cerebral aneurysmal surgery. One hundred and thirty-four patients surgically treated for 147 intracranial aneurysms were studied. Thirteen patients harboring 17 aneurysms were surgically treated on an elective basis, while 121 patients with 130 aneurysms, presented with subarachnoid hemorrhage (SAH). Blood flow velocities of the parent and adjacent vessels as well as the aneurysmal sac were measured using a Conforma Micro-Doppler (Cook Vascular Inc., Leechburg, PA, USA). Pre- and post-operative cerebral angiography was obtained in all our patients. In 23 aneurysms (15.6%) there was decreased or absent flow in the parent vessel or in one of the adjacent vessels after clipping. In another 19 aneurysms (12.9%), MDU demonstrated flow through the aneurysmal dome even though the aneurysmal neck appeared to be totally obliterated. Presence of SAH, anatomic location and size of the aneurysm were associated with improper clip placement in a statistically significant fashion. The false positive rate for MDU was 2% while there were no false negative findings in our study. MDU appears to be a non-invasive, reliable alternative methodology to intra-operative angiography. This inexpensive method may lend itself to routine usage in aneurysm surgery.

Neuronal networks of the basal ganglia and the value of recording field potentials from them.

The basal ganglia constitute parts of highly sophisticated and complex neuronal networks, which represent essential elements of functional circuits, actively involved in the control of movement. The physiologic properties of these networks and their interchange with different brain areas could serve as a model for the pathophysiologic explanation of various movement disorders, particularly Parkinson's disease. Stimulation of these networks and subsequent recording of the evoked Local Field Potentials is currently used not only for understanding the pathophysiology of movement disorders but also for the physiologic localization of the anatomical target during deep brain stimulation procedures. An overview of the currently available research and clinical data from the recording of Local Field Potentials as well as the advantages, the disadvantages and the limitations of this methodology are presented in this chapter.

A novel closed-loop stimulation system in the control of focal, medically refractory epilepsy.

The concept of seizure abortion after prompt detection by employing stimulation is a very appealing one. Several investigators in previous experimental and clinical studies have used stimulation of various anatomical targets with promising results. In this chapter, the authors present their experience with a novel, implantable, local closed-loop responsive neuro-stimulation system (RNS) (Neuropace, Inc., Mountain View, CA, USA). This system consists of a cranially implanted pulse generator, one or two quadripolar subdural strip or depth leads and an external programmer. The system components and technical characteristics are presented. The criteria for selecting candidates for implantation as well as the preliminary results of a clinical trial are also presented. Closed-loop stimulation system appears to be a safe treatment option with promising results for the management of patients with well-localized, focal medically-refractory epilepsy, who are not candidates for surgical resection.

Supratentorial epidural hematoma of traumatic etiology in infants.

INTRODUCTION AND BACKGROUND: Traumatic epidural hematoma (EDH) represents a rare head injury complication in infants. Its diagnosis can be quite challenging because its clinical presentation is usually subtle and nonspecific. In our current communication, we present our data regarding the presentation of infants with EDH, their management, and their long-term outcome. MATERIALS AND METHODS: In a retrospective study, the hospital and outpatient clinic charts and imaging studies (head CT and skull X-rays) of 31 infants with pure, supratentorial EDH of traumatic origin were meticulously reviewed. Children Coma Scale score and Trauma Infant Neurologic Score (TINS) were also reviewed. The most common presenting symptom was irritability, which occurred in 18/31 (58.1%) of our patients. Pallor (in 30/31 patients) and cephalhematoma (in 21/31 patients) were the most commonly occurring clinical signs upon admission; both signs represent signs of significant clinical importance. Surgical evacuation via a craniotomy was required in 24/31 of our patients, while 7/31 patients were managed conservatively. The mortality rate in our series was 6.5% (2/31 patients), and our long-term morbidity rate was 3.2% (1/31 patients). CONCLUSIONS: EDH in infants represents a life-threatening complication of head injury, which requires early identification and prompt surgical or conservative management depending on the patient's clinical condition, size of EDH, and presence of midline structure shift on head CT scan. Mortality and long-term morbidity are low with early diagnosis and prompt treatment.

Spontaneous resolution of acute cranial subdural hematomas.

Acute cranial subdural hematoma (SDH) represents a common consequence of traumatic brain injury. The vast majority of acute SDHs larger than 10mm in thickness require immediate surgical evacuation. In rare occasions, however, spontaneous resolution may occur. In our current communication, we present four cases of spontaneous resolution of acute cranial SDH. Further more, the proposed theories explaining spontaneous resolution of acute SDH, as well as, clinical parameters and imaging characteristics that might predict such phenomenon, are also reviewed. The possibility of spontaneous resolution of an acute SDH, although remote, may impact the decision making process regarding the management of these patients under certain conditions.

Anatomical hemispherectomy.

INTRODUCTION: Anatomical hemispherectomy is frequently employed in the surgical management of pediatric patients with medically refractory epilepsy. MATERIALS AND METHODS: In this chapter, we review the historical evolution of this surgical procedure, outline the indications and the criteria for selecting surgical candidates and describe the important pre-operative evaluation of the surgical candidates. DISCUSSION: We provide a detailed description of our surgical technique, anesthesiological considerations, and post-operative care plan. Ultimately we analyze the most common complications associated with this procedure. CONCLUSION: Anatomical hemispherectomy performed in carefully selected pediatric patients with medically intractable epilepsy can be a safe and efficacious surgical procedure.

Management of intracranial meningeal hemangiopericytomas: outcome and experience.

Hemangiopericytomas represent rare intracranial tumors that have a tendency to recur locally and have the unique characteristic of giving extracranial metastases. Our current communication reviews a series of patients diagnosed with hemangiopericytoma who were treated in our facility. Eleven patients with a mean age of 51.2 years underwent follow-up for a mean time of 7.1 years. Their neuroimaging preoperative evaluation included plain skull X-rays, head CT scans, brain MRI, angiograms, and (1)HMRS. Preoperative embolization of the tumor was employed in 6/11 patients. All patients underwent craniotomy for tumor resection and postoperative radiation treatment was employed on all but one. Grade I resection was accomplished in 6/11 (54.5%), grade III in 4/11 (36.4%), and grade IV in 1/11 (9.1%). Local recurrence was detected in 3/11 (27.3%) at a mean period of 5 (range 2-7.5) years. Extracranial metastatic disease was documented in 4/11 (36.4%) patients at a mean of 4.9 (range 2.5-7) years after the initial diagnosis. The GOS score was: 7/11 (63.6%) scored 5, while 4/11 (36.4%) died at a mean time of 5.5 (range 3-8) years after the initial diagnosis. Intracranial hemangiopericytomas management requires aggressive surgical resection, postoperative radiation treatment, and extensive follow-up to rule out local recurrences and delayed extracranial metastases.

Long-term surgical outcome in patients with intracranial hydatid cyst.

BACKGROUND: Cerebral hydatid cysts account for up to 3.6% of all intracranial space-occupying lesions, in endemic countries. The vast majority of patients affected are children. Computed tomography (CT) and magnetic resonance imaging (MRI) have greatly contributed to a more accurate diagnosis of hydatids. However, correct pre-operative diagnosis still remains quite puzzling. Extirpation of the intact cyst is the treatment of choice, resulting in most cases to a complete recovery. METHOD: In our retrospective study, we have reviewed 76 cases of intra-cranial hydatid disease operated on in our hospital over a 22 year period. Presenting clinical symptoms and signs and the radiological findings on CT and MRI were documented. Albendazole was given preoperatively to patients with giant (>5 cm) or multiple cysts and postoperatively to all patients. The follow-up period ranged from 12 months to 22 years and the outcome was assessed using the Glasgow Outcome Scale (GOS). FINDINGS: Sixty seven (95.7%) of our patients were children. Increased intracranial pressure and papilledema were the predominant findings in this group, whereas focal neurological deficits were most prevalent in adults. CT and MRI revealed round cystic lesions, isodense and iso-intense respectively to cerebrospinal fluid (CSF), with no rim enhancement or perifocal edema. Multiple cysts were identified in 3 cases. Extirpation of the cyst without rupture was accomplished in 56 patients (73.7%). Recurrences occurred in 19 patients (25%). 4 patients (5.3%) died within 6 months after surgery; 3 of these patients had multiple cysts and one died shortly after the operation due to anaphylactic shock following intra-operative rupture of the cyst. CONCLUSION: Long-term follow-up confirms that intracranial hydatid cysts should always be surgically removed without rupture; the outcome remains excellent in these cases. Correct preoperative diagnosis is vital for the successful outcome of surgery. A high index of suspicion is therefore required in endemic areas despite the availability of advanced neuro-imaging. Medical treatment with albendazole seems to be beneficial both pre- and post-operatively. Newer diagnostic methodologies, such as MR spectroscopy and MR diffusion weighted imaging, might lend themselves to the diagnosis of intracranial hydatid cysts.

Review of the literature regarding the relationship of rebleeding and external ventricular drainage in patients with subarachnoid hemorrhage of aneurysmal origin.

Acute hydrocephalus is a well-documented complication of subarachnoid hemorrhage. The insertion of external ventricular drainage (EVD) has been the standard of care in the management of this complication, aiming primarily at immediate improvement of the clinical condition of these patients, making them more suitable candidates for surgical or endovascular intervention. In our current communication, we review the pertinent literature regarding the relationship of rebleeding and EVD. Several studies have implicated a significantly increased risk of rebleeding in patients with EVD, compared with patients without it. Abrupt lowering of the intracranial pressure could lead to rebleeding due to decreased transmural pressure or removal of the clot sealing the previously ruptured aneurysm. However, a variety of parameters that could affect the rebleeding rate, such as the timing of surgery, the timing and duration of drainage, the size of the aneurysm, as well as the severity of the initial hemorrhage, do not seem to have been adequately explored in the majority of these studies. In addition, a number of clinical trials have failed to provide evidence for the negative role of EVD in the development of rebleeding. Conclusively, further long-term multi-center studies are required in order to establish the exact nature of the relationship between EVD and rebleeding after aneurysmal subarachnoid hemorrhage.

The clinical application of non-invasive intracranial blood volume pulse wave monitoring.

An ultrasonic method was used to non-invasively measure intracranial blood volume (IBV) pulse waveforms. This technology has previously shown a strong association between invasively recorded ICP pulse waves and non-invasively recorded IBV pulse waves. The objective of the present study was to investigate the diagnostic value of non-invasively measured IBV pulse waves in the cases of different pathologies. A total of 75 patients were examined and these included cases of acute, chronic and stabilized hydrocephalus, spinal cord injury and terminal blood flow. These were compared to a control group of 53 healthy volunteers. The object of comparison was normalized and averaged IBV pulse waves. Pathological IBV pulse waveforms were compared with IBV pulse waveforms of the normal group using sub-wave values, the area under waveform curve and the Euclidean distance calculation. The non-invasively measured IBV pulse waveform is not significantly dependent on acoustic path, gender or age. A detectable change in IBV pulse waveform shape was observed in situations when disturbance in intracranial hydrodynamics was present, e.g. during hypoventilation tests, in cases of terminal blood flow and hydrocephaly, depicting the level of hydrocephalus activity and the patient's compensatory capabilities as well as the effect of treatment.

Intraventricular administration of rt-PA in patients with intraventricular hemorrhage.

OBJECTIVE: Intraventricular hemorrhage (IVH) represents a clinicopathologic entity with a dismal prognosis. The associated mortality rate has been reported as high as 80%; the morbidity is also quite high. The use of various fibrinolytic agents (streptokinase, urokinase, and recombinant tissue-type plasminogen activator [rt-PA]) has been reported in a small number of clinical series with a very limited number of participants, yielding significant variability regarding inclusion criteria, treatment protocol, and outcome analysis. METHODS: In our prospective study, we report our experience using rt-PA in 21 patients with IVH. Patients with IVH of aneurysmal or arteriovenous malformation origin were excluded. Intraventricular administration of rt-PA was initiated within 24 hours after the ictal event (dose, 3 mg every 24 hours) through a ventricular catheter. The patients' intracranial and cerebral perfusion pressures, cerebrospinal fluid (CSF) cell count, and head CT scans with emphasis to frontal horn dimension and inner cranium diameter at the same level ratio were collected and analyzed. RESULTS: Good outcome was observed in 47.5% of our patients, whereas 28.5% died and 24.0% survived with severe disability. The development of rt-PA-associated complications was as follows: new hemorrhage in 19%, infection in 14.3%, and CSF pleocytosis in 100% of patients. Permanent CSF shunt was required in 40%. The intermediate (3-month) follow up of our survivors showed no significant outcome changes compared with the immediate (1-month) follow up. CONCLUSIONS: Intraventricular administration of rt-PA appears to be beneficial in cases of IVH even though it is occasionally associated with serious complications. Further multi-institutional studies are required for validating this treatment modality and standardizing its parameters.

C1-C2 transarticular screw fixation for atlantoaxial instability.

OBJECTIVES: The atlantoaxial segment of the cervical spine is commonly destabilized in a variety of disorders. Transarticular screw fixation of the C1-C2 joint has been proposed as a biomechanically superior therapeutic modality. The authors present their experience with this technique. METHODS: A retrospective analysis of 23 patients treated with this technique was performed. The mean follow-up period was 39.5 +/- 0.1 months. RESULTS: Mean duration of hospitalization was 3.4 +/- 0.1 days (range, 2 to 11 days). No intraoperative or early postoperative complications were detected. Four patients (17.4%) had postoperative complications unrelated to the primary procedure. The position of the screw was judged as satisfactory in 21 patients (91.3%). Two patients (8.7%) with suboptimal positioning of the screws were neurologically intact but needed no reoperation. Solid osseous fusion was detected in 19 patients (82.6%). CONCLUSIONS: Transarticular C1-C2 screw fixation appears to be a safe and surgically reliable technique. Criteria for its application and refinements in its technical considerations continue to advance its clinically versatile therapeutic potential.