bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spontaneous retroclival hematoma presenting as a thunderclap headache
Authors: Schievink Wouter I. , Thompson Reid C. , Loh Christopher T. , Maya M. Marcel 
Published: May 2009

✓ An excruciating headache of instantaneous onset, or thunderclap headache, may be caused by a variety of serious disorders, including aneurysmal subarachnoid hemorrhage, cerebral venous sinus thrombosis, pituitary apoplexy, and carotid artery or vertebral artery dissection. The authors describe a patient with this type of headache who was found to have a spontaneous retroclival hematoma.
A 49-year-old woman experienced an instantaneous excruciating headache. Results of computerized tomography (CT) scans of the head were normal, but on examination of the cerebrospinal fluid xanthochromia was found. Magnetic resonance (MR) imaging of the cervical spine revealed a retroclival hematoma. Three cerebral angiographic studies did not reveal the source of the hemorrhage and a repeated MR image demonstrated resolution of the hematoma. The patient made an uneventful recovery.
Spontaneous retroclival hematoma is an exceedingly rare type of intracranial hemorrhage and may be associated with normal findings on CT scans. Spontaneous retroclival hematoma should be included in the differential diagnosis of thunderclap headache.
Identification of the carotid artery dural ring by using three-dimensional computerized tomography angiography
Authors: Murayama Yoshihisa , Sakurama Kazuhide , Satoh Koichi , Nagahiro Shinji 
Published: May 2009

✓ The carotid artery (CA) dural ring is an important structure in aneurysm surgery of the paraclinoid region. The authors used three-dimensional computerized tomography (3D-CT) angiography to study the CA dural ring.
Three-dimensional computerized tomography angiography was performed in patients with cerebral aneurysms and other cerebrovascular diseases. The paraclinoid segment of the internal carotid artery (ICA) was examined by the shaded surface reconstruction method on targeted 3D-CT angiography. The concavity was recognized in the paraclinoid segment of the ICA. The relationship between the concavity and the dural ring was investigated with anatomical studies and surgical findings.
In anatomical studies, the concavity in the paraclinoid segment of the ICA on 3D-CT angiography coincided with the level of attachment of the dural ring. Using 3D-CT angiography, it is possible to identify the location of the dural ring in patients being considered for aneurysm surgery.
Adult respiratory distress syndrome: a complication of induced hypertension after severe head injury
Authors: Contant Charles F. , Valadka Alex B. , Gopinath Shankar P. , Hannay H. Julia , Robertson Claudia S. 
Published: May 2009

Object. The factors involved in the development of adult respiratory distress syndrome (ARDS) after severe head injury were studied. The presence of ARDS complicates the treatment of patients with severe head injury, both because hypoxia causes additional injury to the brain and because therapies that are used to protect the lungs and improve oxygenation in patients with ARDS can reduce cerebral blood flow (CBF) and increase intracranial pressure (ICP). In a recent randomized trial of two head-injury management strategies (ICP-targeted and CBF-targeted), a fivefold increase in the incidence of ARDS was observed in the CBF-targeted group.
Methods. Injury severity, physiological data, and treatment data in 18 patients in whom ARDS had developed were compared with the remaining 171 patients in the randomized trial in whom it had not developed. Logistic regression analysis was used to study the interaction of the factors that were related to the development of ARDS.
In the final exact logistic regression model, several factors were found to be significantly associated with an increased risk of ARDS: administration of epinephrine (5.7-fold increased risk), administration of dopamine in a larger than median dose (10.8-fold increased risk), and a history of drug abuse (3.1-fold increased risk).
Conclusions. Although this clinical trial was not designed to study the association of management strategy and the occurrence of ARDS, the data strongly indicated that induced hypertension in this high-risk group of patients is associated with the development of symptomatic ARDS.
Hyperacute measurement of intracranial pressure, cerebral perfusion pressure, jugular venous oxygen saturation, and laser Doppler flowmetry, before and during removal of traumatic acute subdural hematoma
Authors: Verweij Bon H. , Muizelaar J. Paul , Vinas Federico C. 
Published: May 2009

Object. The poor prognosis for traumatic acute subdural hematoma (ASDH) might be due to underlying primary brain damage, ischemia, or both. Ischemia in ASDH is likely caused by increased intracranial pressure (ICP) leading to decreased cerebral perfusion pressure (CPP), but the degree to which these phenomena occur is unknown. The authors report data obtained before and during removal of ASDH in five cases.
Methods. Five patients who underwent emergency evacuation of ASDH were monitored. In all patients, without delaying treatment, a separate surgical team (including the senior author) placed an ICP monitor and a jugular bulb catheter, and in two patients a laser Doppler probe was placed.
The ICP prior to removing the bone flap in the five patients was 85, 85, 50, 59, and greater than 40 mm Hg, resulting in CPPs of 25, 3, 25, 56, and less than 50 mm Hg, respectively. Removing the bone flap as well as opening the dura and removing the blood clot produced a significant decrease in ICP and an increase in CPP. Jugular venous oxygen saturation (SjvO2) increased in four patients and decreased in the other during removal of the hematoma. Laser Doppler flow also increased, to 217% and 211% compared with preevacuation flow.
Conclusions. Intracranial pressure is higher than previously suspected and CPP is very low in patients with ASDH. Removal of the bone flap yielded a significant reduction in ICP, which was further decreased by opening the dura and evacuating the hematoma. The SjvO2 as well as laser Doppler flow increased in all patients but one immediately after removal of the hematoma.
Risk factors affecting survival after brain metastases from non—small cell lung carcinoma: a follow-up study of 70 patients
Authors: Abrahams John M. , Torchia Maria , Putt Mary , Kaiser Larry R. , Judy Kevin D. 
Published: May 2009

Object. The authors present their experience with the treatment of brain metastases from non—small cell lung carcinoma (NSCLC).
Methods. A retrospective review was conducted in which records from 74 patients treated at the authors' institution between 1994 and 1999 were assessed. Survival and functional outcome were reviewed relative to individual patient variables. The median survival time was 12.9 months, with 1-, 2-, and 5-year survival milestones reached by 52.2%, 30.7%, and 18.1% of patients, respectively. Patients were stratified into groups composed of those with synchronous brain metastases (tumors diagnosed within 3 months of NSCLC) and metachronous brain metastases (tumors diagnosed 3 months after NSCLC). The median survival time and 5-year survival rate were 18 months and 28.9% for metachronous, compared with 9.9 months and 0% for synchronous brain metastases. In univariate analyses, the stage of brain metastases, an initial Karnofsky Performance Scale (KPS) score of 90 or less, and conservative therapy for NSCLC were associated with worse outcomes (p < 0.05). In analyses in which tumors were stratified by synchronous compared with metachronous brain metastases, a preoperative KPS score of 90 or less and radiation therapy (RT) alone for brain metastases were associated with worse outcomes in patients with metachronous brain metastases but not with synchronous tumors (p < 0.05). When stratified by preoperative KPS score, the synchronous brain metastases stage or treatment of brain metastases with RT alone were associated with worse outcome in patients with KPS scores of 100, but had no discernible effect on patients with KPS scores of 90 or less (p < 0.05).
Conclusions. The tumor stage and preoperative KPS score were significantly associated with survival. Craniotomy plus RT significantly improved the prognosis in patients with metachronous brain metastases or those with a preoperative KPS score of 100.
Monitoring of intraoperative motor evoked potentials to increase the safety of surgery in and around the motor cortex
Authors: Kombos Theodoros , Suess Olaf , Ciklatekerlio Öczan , Brock Mario 
Published: May 2009

Object. The repetitive application of high-frequency anodal monopolar stimulation during surgery in or near the motor cortex allows a qualitative and quantitative evaluation of motor evoked potentials (MEPs). Using this method, motor pathways and motor function can be continuously monitored during surgery.
Methods. In this prospective study, 70 patients underwent MEP monitoring during surgery performed in the central region. All procedures were performed after general anesthesia had been induced without the aid of muscle relaxants. The motor pathways were monitored during the entire surgical procedure by repetitive high-frequency anodal monopolar stimulation (frequency 400–500 Hz; train 7–10 pulses; impulse duration 0.2–0.7 msec; and stimulation intensity 16.9 ± 7.76 mA). The MEPs were continuously evaluated to assess their latency, potential duration, and amplitude. Recorded alterations in these parameters were subsequently correlated with surgical maneuvers and with postoperative neurological deterioration.
The monitoring parameters (latency, potential duration, and amplitude) had a broad interindividual range of variation. A correlation between individual intraoperative changes in the potentials and surgical maneuvers or postoperative neurological deterioration was observed in eight cases. A spontaneous shift in latency greater than 15% or a sudden reduction in the amplitude of the potential greater than 80% was considered a warning criterion. In all cases in which there was an irreversible change in latency or a complete loss of potentials were observed, there was postoperative neurological deterioration.
Conclusions. Improved surgical safety can be achieved using intraoperative neurophysiological monitoring procedures. Repetitive stimulation of the motor cortex proved to be a reliable method for monitoring subcortical motor pathways. Changes in MEP latency and MEP amplitude served as warning criteria during surgery and possessed prognostic value.
Strategies for reoperation after comprehensive epilepsy surgery
Authors: Schwartz Theodore H. , Spencer Dennis D. 
Published: May 2009

Object. Prior reports of seizure control following reoperation for failed epilepsy surgery have shown good results. These studies included patients who presented during the era preceding magnetic resonance (MR) imaging, and the patients were often not monitored intracranially or underwent subtotal hippocampal resections. In this study, the authors hypothesized that reoperation for recurrent seizures following a more comprehensive initial workup and surgery would not yield such good results.
Methods. The authors examined a consecutive series of patients who underwent two operations at Yale—New Haven Hospital for medically intractable epilepsy and in whom there was a minimum of 1-year follow up after the second surgery. All patients were evaluated and treated according to a standard protocol, including preoperative MR imaging, a low threshold for invasive monitoring, and a radical amygdalohippocampectomy when indicated.
Twenty-seven patients were identified (five with mesial temporal sclerosis, 20 with neocortical disease, and two with multifocal sites of seizure onset) of whom six (22%) underwent intentionally palliative second surgery (corpus callostomy or placement of a vagus nerve stimulator [VNS]). Of the remaining 21 patients, only four (19%) became seizure free after a second resective operation. The most common causes of treatment failure were dual pathology, recurrent tumor, limited resection to preserve function, widespread developmental abnormalities, and electrographic sampling error. Successful outcomes resulted from removal of recurrent tumors, completion of a functional hemispherectomy, or repeated invasive monitoring to correct a sampling error. Five (83%) of the six intentionally palliative second operations resulted in more than a 50% decrease in seizure frequency.
Conclusions. If an aggressive preoperative evaluation and surgical resection are performed, reoperation for recurrent seizures has a much lower likelihood of cure than previously reported. Intentionally palliative surgery such as placement of a VNS unit may be considered for patients in whom the initial operation fails to decrease seizure frequency.
Endovascular treatment with Guglielmi detachable coils for basilar artery trunk aneurysms: clinical experience with 41 aneurysms in 39 patients
Authors: Uda Ken , Murayama Yuichi , Gobin Y. Pierre , Duckwiler Gary R. , Viñuela Fernando 
Published: May 2009

Object. The authors present a retrospective analysis of their clinical experience in the endovascular treatment of basilar artery (BA) trunk aneurysms with Guglielmi detachable coils (GDCs).
Methods. Between April 1990 and June 1999, 41 BA trunk aneurysms were treated in 39 patients by inserting GDCs. Twenty-seven patients presented with subarachnoid hemorrhage, six had intracranial mass effect, and in six patients the aneurysms were found incidentally. Eighteen lesions were BA trunk aneurysms, 13 were BA—superior cerebellar artery aneurysms, four were BA—anterior inferior cerebellar artery aneurysms, and six were vertebrobasilar junction aneurysms. Thirty-five patients (89.7%) had excellent or good clinical outcomes; procedural morbidity and mortality rates were 2.6% each. Thirty-six aneurysms were selectively occluded while preserving the parent artery, and in five cases the parent artery was occluded along with the aneurysm. Immediate angiographic studies revealed complete or nearly complete occlusion in 35 aneurysms (85.4%). Follow-up angiograms were obtained in 29 patients with 31 aneurysms; the mean follow-up period was 17 months. No recanalization was observed in the eight completely occluded aneurysms. In 19 lesions with small neck remnants, seven (36.8%) had further thrombosis, three (15.8%) remained anatomically unchanged, and nine (47.3%) had recanalization caused by coil compaction. In one patient (2.6%) the aneurysm rebled 8 years after the initial embolization.
Conclusions. In this clinical series the authors show that the GDC placement procedure is valuable in the therapeutic management of BA trunk aneurysms. The endovascular catheterization of these lesions tends to be relatively simple, in contrast with more complex neurosurgical approaches. Endosaccular obliteration of these aneurysms also decreases the possibility of unwanted occlusion of perforating arteries to the brainstem.
Radiosurgery-induced brain tumor
Authors: Kaido Takanobu , Hoshida Tohru , Uranishi Ryunosuke , Akita Nobuhisa , Kotani Akihira , Nishi Noriyuki , Sakaki Toshisuke 
Published: May 2009

✓ The authors describe a case of glioblastoma multiforme (GBM) associated with previous gamma knife radiosurgery for a cerebral arteriovenous malformation (AVM). A 14-year-old boy had undergone radiosurgery for an AVM, which was performed using a 201-source 60Co gamma knife system at another institution. The maximum and margin radiation doses used in the procedure were 40 and 20 Gy, respectively. One year after radiosurgery, the patient noticed onset of mild left hemiparesis due to radiation necrosis.
Six and one-half years after radiosurgery, at the age of 20 years, the patient experienced an attack of generalized tonic—clonic seizure. Magnetic resonance (MR) imaging revealed the existence of a brain tumor in the right parietal lobe. The patient underwent an operation and the histological diagnosis of the lesion was GBM. Ten months following the operation, that is, 99 months postradiosurgery, this patient died.
To the best of the authors' knowledge, this is the first reported case of a neoplasm induced by radiosurgery for an AVM and the second case in which it occurred following radiosurgery for intracranial disease.
Cerebral autoregulation following head injury
Authors: Czosnyka Marek , Smielewski Piotr , Piechnik Stefan , Steiner Luzius A. , Pickard John D. 
Published: May 2009

Object. The goal of this study was to examine the relationship between cerebral autoregulation, intracranial pressure (ICP), arterial blood pressure (ABP), and cerebral perfusion pressure (CPP) after head injury by using transcranial Doppler (TCD) ultrasonography.
Methods. Using ICP monitoring and TCD ultrasonography, the authors previously investigated whether the response of flow velocity (FV) in the middle cerebral artery to spontaneous variations in ABP or CPP provides reliable information about cerebral autoregulatory reserve. In the present study, this method was validated in 187 head-injured patients who were sedated and receiving mechanical ventilation. Waveforms of ICP, ABP, and FV were recorded over intervals lasting 20 to 120 minutes. Time-averaged mean FV and CPP were determined. The correlation coefficient index between FV and CPP (the mean index of autoregulation [Mx]) was calculated over 4-minute epochs and averaged for each investigation.
The distribution of averaged mean FV values converged with the shape of the autoregulatory curve, indicating lower (CPP < 55 mm Hg) and upper (CPP > 105 mm Hg) thresholds of autoregulation. The relationship between the Mx and either the CPP or ABP was depicted as a U-shaped curve. Autoregulation was disturbed in the presence of intracranial hypertension (ICP ≥ 25 mm Hg) and when mean ABP was too low (ABP < 75 mm Hg) or too high (ABP > 125 mm Hg). Disturbed autoregulation (p < 0.005) and higher ICP (p < 0.005) occurred more often in patients with unfavorable outcomes than in those with favorable outcomes.
Conclusions. Autoregulation not only is impaired when associated with a high ICP or low ABP, but it can also be disturbed by too high a CPP. The Mx can be used to guide intensive care therapy when CPP-oriented protocols are used.
Chiari I malformation: a rare cause of noncommunicating hydrocephalus treated by third ventriculostomy
Authors: Decq Philippe , Guérinel Caroline Le , Sol Jean-Christophe , Brugières Pierre , Djindjian Michel , Nguyen Jean-Paul 
Published: May 2009

Object. Hydrocephalus associated with Chiari I malformation is a rare entity related to an obstruction in the flow of cerebrospinal fluid (CSF) in the foramen of Magendie. Like all forms of noncommunicating hydrocephalus, it can be treated by endoscopic third ventriculostomy (ETV). The object of this study is to report a series of five cases of hydrocephalus associated with Chiari I malformation and to evaluate the use of ETV in the treatment of this anomaly.
Methods. Five patients (four women and one man with a mean age of 29.6 years) underwent ETV for hydrocephalus associated with Chiari I malformation between April 1991 and February 1997. All patients had presented with paroxysmal headaches, which in two cases were associated with visual disorders. All patients had also presented with hydrocephalus (mean transverse diameter of the third ventricle 12.79 mm; mean sagittal diameter of the fourth ventricle 18.27 mm) with a mean herniation of the cerebellar tonsils at 13.75 mm below the basion—opisthion line. Surgery was performed in all patients by using a rigid endoscope. No complications occurred either during or after the procedure, except in one patient who experienced a wound infection that was treated by antibiotic medications.
The mean duration of follow up in this study was 50.39 months. Four patients became completely asymptomatic and remained stable throughout the follow-up period. One patient required an additional third ventriculostomy after 1 year, due to secondary closure, and has remained stable since that time. Postoperative magnetic resonance images demonstrated a significant reduction in the extent of hydrocephalus in all patients (mean transverse diameter of the third ventricle 6.9 mm [p = 0.0035]; mean sagittal diameter of the fourth ventricle 10.32 mm [p = 0.007]), with a mean ascent of the cerebellar tonsils from 13.75 mm below the basion—opisthion line to 7.76 mm below it (p = 0.01). In addition, CSF flow was identified on either side of the orifice of the third ventriculostomy in all patients postoperatively.
Conclusions. Results in this series confirm the efficacy of ETV in the treatment of hydrocephalus associated with Chiari I malformation. It is a reliable, minimally invasive technique that also provides a better understanding of the pathophysiology of this malformation.
Functional and diffusion-weighted magnetic resonance images of space-occupying lesions affecting the motor system: imaging the motor cortex and pyramidal tracts
Authors: Krings Timo , Reinges Marcus H. T. , Thiex Ruth , Gilsbach Joachim M. , Thron Armin 
Published: May 2009

Object. During neurosurgical interventions, preservation of subcortical axons is as important as preservation of cortical neurons. The goal of this study was to assess the combined use of functional (f) and diffusion-weighted (DW) magnetic resonance (MR) imaging to assist in the preservation of the structure and function of the motor system.
Methods. The authors evaluated the combination of fMR imaging and DW MR imaging to detect cortical motor areas with their corresponding pyramidal tracts in 12 healthy volunteers and in 10 consecutive patients with various space-occupying lesions affecting the central motor system.
Activation within the primary motor cortex (M1) and white matter bundles originating from this cortical region was demonstrated in 21 of the 22 individuals examined. Additional activation was exhibited along the course of white matter tracts at the level of the pons and, in the contralateral hemisphere, in the M1. Fiber tract displacement was visualized in all patients in white matter that had appeared normal on routine T1- and T2-weighted MR images.
Conclusions. The combination of DW MR and fMR imaging allows visualization of the origin, direction, and functionality of large white matter tracts. This will prove helpful for imaging structural connectivity within the brain during functional imaging. Moreover, local relationships of cerebral tumors that encroach upon M1 and subcortical fiber tracts can be defined. This promises to decrease patient morbidity and to broaden the clinical applications of functional imaging.