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Background: Medical knowledge during the medieval ages flourished under the influence of great scholars of the Islamic Golden age such as Ibn Sina (Latinized as Avicenna), Abu Bakr al-Razi (Rhazes), and Abu al-Qasim Khalaf ibn al-Abbas al-Zahrawi, known as Albucasis. Much has been written on al-Zahrawi's innovation in various disciplines of medicine and surgery. In this article, we focus for on the contributions of al-Zahrawi toward the treatment of neurological disorders in the surgical chapters of his medical encyclopedia, Kitab al-Tasrif (The Method of Medicine)., Methods: Excerpts from a modern copy of volume 30 of al-Zahrawi's Kitab al-Tasrif were reviewed and translated by the primary author from Arabic to English, to further provide specific details regarding his neurosurgical knowledge. In addition, a literature search was performed using PubMed and Google Scholar to review prior reports on al-Zahrawi's neurosurgical instructions., Results: In addition to what is described in the literature of al-Zahrawi's teachings in cranial and spine surgery, we provide insight into his diagnosis and management of cranial and spinal trauma, the devices he used, and prognostication of various traumatic injuries., Conclusions: Al-Zahrawi was a renowned physician during the Islamic Golden age who made significant contributions to the diagnosis and treatment of neurological conditions, particularly cranial and spinal cord injuries. He developed innovative surgical techniques for trephination and spinal traction, which are still used in modern neurosurgery. His insights make him worthy of recognition as an important figure in the history of neurological surgery., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Tenosynovial giant cell tumor (TGCT) occurs most commonly in the appendicular skeleton and is only rarely found in the vertebral column. Lesions of the craniocervical junction are particularly rare, with only 4 cases reported in the literature. The authors describe the case of a diffuse-type TGCT at the craniocervical junction., Observations: A patient presented with a 1-year history of right-sided neck pain and bilateral neurological symptoms in the distribution of the right occipital nerve. A 20-mm homogeneously contrast-enhancing mass in the suboccipital and posterior C1 region was discovered on magnetic resonance imaging of the cervical spine. The tumor was operated on via a posterior approach, and gross-total resection (GTR) was achieved. Immunohistochemical (IHC) examination revealed a diffuse-type TGCT. The patient had an uneventful recovery., Lessons: TGCT can arise at the craniocervical junction and is easily misdiagnosed because of its rare occurrence. IHC examination of a tumor specimen should be done to confirm the diagnosis. GTR is the objective when treating these tumors, especially when they are the diffuse type, as they have a high recurrence rate. Radiation and small-molecule therapies are viable postoperative therapies if GTR cannot be achieved or in cases of recurrence.

Background: The relationship between marital status and overall survival (OS) in adult patients with craniopharyngioma has not been explored in depth. We aimed to elucidate the impact of marital status on the prognosis of craniopharyngioma patients excluding bias from baseline demographics and treatment., Methods: We extracted 1539 patients diagnosed with craniopharyngioma between 2000 and 2019 from the Surveillance, Epidemiology, and End Results database and divided patients into 4 marital subgroups: married, single, divorced/separated, and widowed. Kaplan-Meier curves with a log-rank test were used to discern differences in OS between marital subgroups. Univariate and multivariate Cox regression were used to identify independent prognostic factors of mortality., Results: There were 1539 eligible patients: 863 (56.1%) were married, 466 (30.3%) were single, 135 (8.8%) were divorced/separated, and 75 (4.9%) were widowed. Widowed patients had the worst mean OS, 5-year OS and 10-year OS at 84.2 months, 58.0% and 26.9%, respectively. After stratifying patients by age, our multivariate analysis showed that marital status was an independent predictor of mortality in middle-aged craniopharyngioma patients (40-60 years, P < 0.001), but not in young adults (18-39 years, P = 0.646) or elderly patients (>60 years, P = 0.076). Among middle-aged patients, single (hazard ratio 1.72, confidence interval 1.19-2.47, P = 0.004) and divorced/separated patients (hazard ratio = 2.29, confidence interval = 1.49-3.54, P < 0.001) showed a higher risk of mortality compared to married patients (reference)., Conclusions: Marital status is an independent prognostic factor predicting OS for middle-aged patients with craniopharyngioma. Providing additional social and psychological support for single and divorced/separated patients may improve outcomes for this vulnerable population., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to evaluate the efficacy of transcarotid arterial revascularization (TCAR) as a viable intervention in the treatment of symptomatic carotid artery stenosis., Methods: The authors performed a retrospective review of prospectively collected data of the first 62 consecutive patients treated at Rhode Island Hospital in Providence, Rhode Island, who underwent a TCAR for symptomatic carotid artery stenosis between November 11, 2020, and March 31, 2022. Relevant demographic, comorbidity, and perioperative data were extracted through retrospective chart review. Patients with asymptomatic carotid artery stenosis were excluded. The authors also evaluated patients using pertinent physiological and anatomical high-risk criteria as described in the ROADSTER trial. Risk factors were aggregated to form a composite risk total for every patient. The primary outcome of this study was the 30-day adverse outcome rate of stroke, myocardial infarction, and/or death. Periprocedural stroke was identified by clinical symptoms and radiographic findings. Secondary endpoints included device and procedural success, 30-day mortality, 30-day stroke rate, and postoperative complications., Results: The authors analyzed the first 62 patients with > 50% symptomatic carotid artery stenosis who underwent TCAR at their institution. The mean age of the cohort was 71.5 years, and the cohort was predominantly male (67.7%). The most common high-risk medical criteria were age older than 75 years (45.3%) and severe coronary artery disease (13.6%). The most common anatomical high-risk criteria were high bifurcation (35.1%) and contralateral stenosis requiring treatment within 30 days (15.8%). Fifty percent of patients had at least 1 medical high-risk criterion, 50% had at least 1 anatomical risk criterion, and 82% of patients had 2 or more high-risk criteria of any kind. Among this group, all patients (100%) underwent successful revascularization, with 1 (1.6%) requiring intraprocedural conversion to carotid endarterectomy. Postprocedurally, there was 1 nondisabling stroke (1.6%) and 3 deaths (4.8%) within 30 days of the procedure, with only 1 death directly attributable to the procedure. One patient (1.6%) experienced a neck hematoma. In total, 4 patients (6.5%) experienced a major complication. The overall complication rate was 8.0%., Conclusions: The authors' initial experience with TCAR suggests that it might provide an effective alternative to carotid endarterectomy and carotid artery stenting in the management of symptomatic carotid stenosis in patients with high-risk anatomical and medical characteristics.

Delayed cerebral ischemia (DCI) is a major etiology of poor neurologic outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Although the development of DCI is certainly multifactorial, the presence of vasospasm is strongly correlated with it. Cerebral angiography remains the gold standard for evaluation of vasospasm, though it is not always practical or cost-effective. In this study, the authors assess the utility of automated MRI Perfusion imaging, with or without MR Angiography (MRA), as a confirmatory tool for suspected angiographic vasospasm. All patients admitted to a single institution with aneurysmal subarachnoid hemorrhage between January 2014 and February 2020 and who underwent MR Perfusion imaging with or without MRA for suspected vasospasm no >24 h prior to an angiogram were identified. 43 subjects were identified. 29 of these patients (67%) underwent simultaneous MRA. 25 patients (53%) received intra-arterial treatment for symptomatic vasospasm. The sensitivity, specificity, PPV, and NPV of MR Perfusion were 43%, 82%, 53%, and 75% for any angiographic vasospasm and 57%, 81%, 42%, and 89% for treated vasospasm. The sensitivity, specificity, PPV, and NPV of MR Perfusion in conjunction with MRA were 61%, 81%, 59%, and 82% for any angiographic vasospasm and 62%, 74%, 35%, and 89% for treated vasospasm. The sensitivity, specificity, PPV, and NPV of transcranial Dopplers (TCDs) in these patients were 35%, 93%, 71%, and 75% for angiographic vasospasm and 42%, 90%, 47%, and 88% for treated vasospasm. Automated MR Perfusion imaging demonstrated relatively low sensitivity and PPV for detection of angiographic and treated vasospasm in this subset of patients after aSAH., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: To evaluate the feasibility of awake transforaminal endoscopic surgery in the management of symptomatic spinal metastases., Methods: Transforaminal endoscopic spine procedures were performed by 1 surgeon in 325 patients over a period of 4 years from 2014 to 2018. Four of these patients suffered from radicular pain secondary to nerve compression from metastatic spine disease and are the basis of our analysis. Data was evaluated retrospectively in these patients with a minimum follow up of 1 year., Results: All 4 patients treated with transforaminal endoscopic spine surgery for decompression of their metastatic spine disease had successful resolution of their symptoms without any perioperative complications and only brief recovery periods required., Conclusions: Awake endoscopic surgery for the treatment of symptomatic metastatic spine disease is an effective outpatient surgical option for the treatment of patients suffering from radicular pain due to nerve compression from metastatic spine disease., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/jss.2019.10.14). The series “Full-endoscopic Spine Surgery” was commissioned by the editorial office without any funding or sponsorship. The authors have no other conflicts of interest to declare., (2020 Journal of Spine Surgery. All rights reserved.)

Background: Platelet transfusion has been utilized to reverse platelet dysfunction in patients on preinjury antiplatelets who have sustained a traumatic intracranial hemorrhage (tICH); however, there is little evidence to substantiate this practice. The objective of this study was to perform a systematic review on the impact of platelet transfusion on survival, hemorrhage progression and need for neurosurgical intervention in patients with tICH on prehospital antiplatelet medication., Methods: Controlled, observational and randomized, prospective and retrospective studies describing tICH, preinjury antiplatelet use, and platelet transfusion reported in PubMed, Embase, Cochrane Reviews, Cochrane Trials and Cochrane DARE databases between January 1987 and March 2019 were included. Investigations of concomitant anticoagulant use were excluded. Risk of bias was assessed using the Newcastle-Ottawa scale. We calculated pooled estimates of relative effect of platelet transfusion on the risk of death, hemorrhage progression and need for neurosurgical intervention using the methods of Dersimonian-Laird random-effects meta-analysis. Sensitivity analysis established whether study size contributed to heterogeneity. Subgroup analyses determined whether antiplatelet type, additional blood products/reversal agents, or platelet function assays impacted effect size using meta-regression., Results: Twelve of 18,609 screened references were applicable to our questions and were qualitatively and quantitatively analyzed. We found no association between platelet transfusion and the risk of death in patients with tICH taking prehospital antiplatelets (odds ratio [OR], 1.29; 95% confidence interval [CI], 0.76-2.18; p = 0.346; I = 32.5%). There was no significant reduction in hemorrhage progression (OR, 0.88; 95% CI, 0.34-2.28; p = 0.788; I = 78.1%). There was no significant reduction in the need for neurosurgical intervention (OR, 1.00; 95% CI, 0.53-1.90, p = 0.996; I = 59.1%; p = 0.032)., Conclusion: Current evidence does not support the use of platelet transfusion in patients with tICH on prehospital antiplatelets, highlighting the need for a prospective evaluation of this practice., Level of Evidence: Systematic Reviews and Meta-Analyses, Level III.

Objective: Perineural cysts are a benign spine pathology but, when they become symptomatic and require surgical treatment, represent a significant challenge to the spine surgeon. Here we describe our experience with a novel endoscopic approach to the biopsy, drainage, resection of the cyst wall, and direct cyst fenestration to the subarachnoid space., Methods: A transforaminal endoscopic approach to a large lumbar 2-3 perineural cyst is presented here in a 25-year-old patient. A step-by-step technique for the biopsy, drainage, and resection of the cyst wall is presented., Results: The patient underwent cyst resection and fenestration into the subarachnoid space without complication, with immediate relief of his preoperative symptoms and after 1 year remains symptom-free., Conclusions: Surgical treatment of perineural cysts in the spine represent a significant challenge to the surgeon, principally due to the risk of spinal fluid leak in the postoperative period. Transforaminal endoscopic surgical access to this disease pathology is a novel minimally invasive surgical approach presented here that allows diagnosis and treatment of a perineural cyst and can be performed in an awake patient., (Copyright © 2019. Published by Elsevier Inc.)

Background: Foot drop that results from compression of the exiting L5 nerve as a result of far lateral disc herniation (FLDH) at L5-S1 poses a significant surgical challenge to the minimally-invasive spine surgeon given the narrow corridor for an extraforaminal approach because of the high iliac crest., Objectives: Here we describe our experience with transforaminal endoscopic decompression for the treatment of foot drop secondary to FLDH at L5-S1., Study Design: Retrospective case review., Setting: This study took place in a single-center, academic hospital., Methods: A technique for the transforaminal endoscopic treatment of foot drop secondary to L5-S1 FLDH is presented in a series of 5 consecutive patients treated over a period of 3 years. Preoperative and postoperative clinical data with 1-year follow-up are presented., Results: A consecutive series of 211 patients who underwent transforaminal endoscopic treatment for lumbar radiculopathy between 2011 and 2014 are presented. Seventy-seven patients had L5-S1 discectomies and 5 of those patients presented with foot drop and FLDH. The mean visual analog scale score for radicular pain improved from an average pain score before surgery of 7.2 to 0.8 one year after surgery, and the mean motor score for anterior tibialis strength improved from an average motor score before surgery of 2.6 to 4.8 one year after surgery., Limitations: Small case series evaluated retrospectively with one year follow-up., Conclusions: Transforaminal endoscopic surgical access to FLDH pathology may be a unique approach to the treatment of foot drop because it allows for neural decompression of disc and foraminal pathology without requiring significant destabilizing bone removal., Key Words: Endoscopic spine surgery, minimally-invasive, transforaminal, foot drop, far lateral disc herniation.

Objective: Traumatic intracranial hemorrhage (tICH) is a significant source of morbidity and mortality in trauma patients. While prognostic models for tICH outcomes may assist in alerting clinicians to high-risk patients, previously developed models face limitations, including low accuracy, poor generalizability, and the use of more prognostic variables than is practical. This study aimed to construct a simpler and more accurate method of risk stratification for all tICH patients., Methods: The authors retrospectively identified a consecutive series of 4110 patients admitted to their institution's level 1 trauma center between 2003 and 2013. For each admission, they collected the patient's sex, age, systolic blood pressure, blood alcohol concentration, antiplatelet/anticoagulant use, Glasgow Coma Scale (GCS) score, Injury Severity Score, presence of epidural hemorrhage, presence of subdural hemorrhage, presence of subarachnoid hemorrhage, and presence of intraparenchymal hemorrhage. The final study population comprised 3564 patients following exclusion of records with missing data. The dependent variable under study was patient death. A k-fold cross-validation was carried out with the best models selected via the Akaike Information Criterion. These models risk stratified the study partitions into grade I (< 1% predicted mortality), grade II (1%-10% predicted mortality), grade III (10%-40% predicted mortality), or grade IV (> 40% predicted mortality) tICH. Predicted mortalities were compared with actual mortalities within grades to assess calibration. Concordance was also evaluated. A final model was constructed using the entire data set. Subgroup analysis was conducted for each hemorrhage type., Results: Cross-validation demonstrated good calibration (p < 0.001 for all grades) with a mean concordance of 0.881 (95% CI 0.865-0.898). In the authors' final model, older age, lower blood alcohol concentration, antiplatelet/anticoagulant use, lower GCS score, and higher Injury Severity Score were all associated with greater mortality. Subgroup analysis showed successful stratification for subarachnoid, intraparenchymal, grade II-IV subdural, and grade I epidural hemorrhages., Conclusions: The authors developed a risk stratification model for tICH of any GCS score with concordance comparable to prior models and excellent calibration. These findings are applicable to multiple hemorrhage subtypes and can assist in identifying low-risk patients for more efficient resource allocation, facilitate family conversations regarding goals of care, and stratify patients for research purposes. Future work will include testing of more variables, validation of this model across institutions, as well as creation of a simplified model whose outputs can be calculated mentally.

Purpose: Traumatic subdural hemorrhage (SDH) is associated with high mortality, yet many patients are not managed surgically. We sought to understand what factors might be associated with SDH enlargement to contribute to the triage of these conservatively managed patients., Materials and Methods: A consecutive series of 117 patients admitted to our institution's level 1 trauma center for SDH between January 1, 2010 and December 31, 2010 were evaluated. Volumetric measurement of SDHs was performed on initial and follow-up head computed tomography (CT) scans with recording of initial midline shift and classification by location. Multimodel analysis quantified associations with change in SDH volume., Results: Systolic blood pressure, presence of subarachnoid hemorrhage, and initial SDH volume demonstrated positive associations with change in SDH volume, while initial midline shift and transfusion of platelets demonstrated negative associations. Initial convexity SDH volume demonstrated positive association with change in convexity SDH volume, while initial midline shift and transfusion of platelets demonstrated negative associations. Anticoagulant/antiplatelet use demonstrated positive association with change in tentorial SDH volume, while time between CT scans demonstrated negative association., Conclusions: Platelet transfusion, anticoagulation, and hypertension have significant associations with expansion in non-surgical cases of SDH. Monitoring these factors may assist triaging these patients., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Here, the authors examined the factors involved in the volumetric progression of traumatic brain contusions. The variables significant in this progression are identified, and the expansion rate of a brain bleed can now effectively be predicted given the presenting characteristics of the patient.

Stroke is a major cause of death and disability in the United States and rapid evaluation and treatment of stroke patients are critical to good outcomes. Effective surgical treatments aim to restore adequate cerebral blood flow, prevent secondary brain injury, or reduce the likelihood of recurrent stroke. Patient evaluation in centers with a comprehensive stroke program and a dedicated neuro- vascular team is recommended. [Full article available at http://rimed.org/rimedicaljournal-2017-06.asp].

There have been infrequent reports of isolated central nervous system blastomycosis. We report a case of intracranial epidural abscess secondary to Blastomyces dermatitidis in a patient residing in Rhode Island with a history of remote travel to an endemic area. The clinical, radiographic, and pathologic features of this unique case are reviewed.

Ralstonia eutropha H16 is capable of utilizing 3,3'-thiodipropionic acid (TDP) and 3,3'-dithiodipropionic acid (DTDP) as precursor substrates for biosynthesis of a polythioester (PTE) heteropolymer consisting of 3-hydroxybutyric acid (3HB) and 3-mercaptopropionic acid (3MP). To elucidate the hitherto unknown catabolic pathways of TDP and DTDP in R. eutropha H16, 19 defined deletion mutants were generated based on extensive functional genome analyses. Deletions of two ABC-type transporter clusters (H16&#95;A0357-0359, H16&#95;A3658-3660) resulted in an alteration of poly(3HB-co-3MP) composition with TDP as precursor to only 10.2±1.9mol% 3MP in comparison to 15.1±5.5mol% in the wild type. A mutant strain of H16 lacking Bordetella uptake gene-like substrate binding proteins (H16&#95;A2779, H16&#95;A0337) incorporated only 7.4±3.8mol% 3MP into PTE heteropolymers with DTDP as precursor in comparison to 24.5±14.5mol% in the wild type. Therefore, both gene products are probably involved in transport processes of this compound into the cells. However, the most significant reduction in 3MP contents of the heteropolymers with DTDP as precursor occurred upon the deletion of a gene encoding the putative thiol-disulfide interchange protein DsbD (H16&#95;A3455, 3.9±2.6mol% 3MP). DsbD is proposed to be involved in the reduction of DTDP into two molecules of 3MP, the common cleavage product of TDP and DTDP., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The field of endovascular therapy has demonstrated stunning technical achievements in AVM embolization. Embolization has the potential to enhance the safety and efficacy of AVM treatment when applied in carefully considered cases. The utility of embolization, at the present time, is limited by the fact that the procedure may be associated with disabling or fatal complications, and because complete or near-complete AVM nidus occlusion can be achieved only in a minority of cases. Because of these factors, embolization should not be considered a "standard-of-care" for the management of all cerebral AVMs, and careful case selection for embolization, with well-defined treatment goals in mind, is essential. Finally, not all AVMs that can be embolized should be embolized.

Objective: Our goal was to assess the value of MR imaging to patient care in the setting of angiographically negative subarachnoid hemorrhage and to evaluate the potential of MR imaging for revealing the mechanism for idiopathic perimesencephalic subarachnoid hemorrhage., Materials and Methods: We retrospectively reviewed 71 patients who presented with subarachnoid hemorrhage and in whom the results of a four-vessel cerebral arteriogram were negative, a CT scan showed no evidence of intraaxial hemorrhage, and MR imaging had been performed within 72 hr of presentation. MR imaging of the brain included sagittal spin-echo T1-weighted, turbo spin-echo proton density-weighted, T2-weighted, and axial T2-weighted gradient-echo sequences. MR imaging of the cervical spine, which was performed in 41 of the 71 patients, included sagittal spin-echo T1-weighted, turbo spin-echo proton density-weighted, T2-weighted, and axial T2-weighted gradient-echo sequences., Results: Perimesencephalic subarachnoid hemorrhage was seen on CT in 25 patients; in four of these patients (16%), MR imaging revealed acute perforator territory infarction involving the caudate, putamen, or thalamus. In 26 other patients, nonperimesencephalic subarachnoid hemorrhage was revealed on CT; in two of these patients (8%), MR imaging showed the cause of the subarachnoid hemorrhage. By contrast, 20 patients had negative findings on CT scans but xanthochromic CSF on lumbar puncture; in two of these patients (10%), MR findings were interpreted as responsible for subarachnoid hemorrhage., Conclusion: MR imaging showed diagnostic value in patients with angiographically negative subarachnoid hemorrhage, revealing abnormalities in 14% of the 71 patients, and resulted in a significant change in patient treatment in 6% of the patients. MR imaging also revealed an association between perimesencephalic subarachnoid hemorrhage and infarcts involving the territory of perforating arteries at the base of the brain. This finding may provide insight into the pathogenesis of perimesencephalic subarachnoid hemorrhage.

Although neuronal death has been studied in experimental models of ischemia, the precise mechanisms regulating cell death remain unclear. Furthermore, the timing and pattern of neuronal death in human stroke has not been extensively studied. To further our understanding of ischemia-induced neuronal death, we examined the temporal profile of histochemical and morphologic characteristics of hippocampal neuronal death following experimental forebrain ischemia and compared these findings to human brain specimens obtained from subjects suffering cerebral infarction. Transient forebrain ischemia (TFI) was induced in normothermic adult rats by bilateral carotid artery occlusion combined with hypotension. Animals were sacrificed at 6, 12, 18, 24, 48, and 72 h and 7, 14, and 28 days following ischemia (n = 4 at each time point). Experimental tissue was analyzed using light and electron microscopy as well as TUNEL histochemistry. A total of 27 human brain specimens with neuropathological confirmation of ischemic damage and appropriate controls were also examined using light microscopy and TUNEL histochemistry. Dense TUNEL staining in hippocampal CA-1 neurons was present at 48 and 72 h following experimental ischemia. Prior to these times, little or no nuclear staining was noted and after 72 h nuclear staining diminished rapidly. Ultrastructural findings at these time points demonstrated many features similar to those seen in cells undergoing apoptosis, such as cell shrinkage with increased electron density, chromatin condensation with formation of heterochromatin, intact plasma membranes, and intact intracellular organelles. In a similar fashion, human stroke specimens during the subacute period showed dense nuclear TUNEL staining in penumbral neurons, whereas in the acute or chronic stages little or no staining was noted. Our results demonstrate that the timing of morphologic changes and TUNEL histochemistry following human stroke resembles that observed in experimental TFI. Furthermore, neuronal death in both experimental ischemia and human stroke share several features characteristic of apoptotic cell death.

Posttraumatic cerebral arterial spasm (vasospasm) has been demonstrated in the past by angiography, and recently by transcranial Doppler ultrasonography. Posttraumatic vasospasm is a delayed complication that involves the large basal intracranial arteries (e.g., internal carotid, middle cerebral, basilar) and occurs in 25-40% of head trauma patient. The time course of posttraumatic vasospasm resembles that of vasospasm associated with aneurysmal subarachnoid hemorrhage with onset occurring 2 or more days after injury. A study of the relationship of admission CT scan findings to the incidence of vasospasm suggests that intradural bleeding, which extends into the CSF (subarachnoid, intraventricular, and subdural hemorrhage), plays a role in the pathogenesis of posttraumatic arterial spasm. The preliminary results of a large prospective study of head trauma patients suggest that vasospasm may be an important determinant of outcome from severe head injury.

This article has addressed the rationale for the clinical measurement of CBF in the neuro-surgical ICU. The techniques that are currently available for measurement of CBF have been reviewed, and those that are particularly appropriate for ICU use have been highlighted. Several examples of the role of CBF monitoring in the management of ICU patients have been described, and these clinical situations are considered further in other articles in this issue regarding the management of patients with head injury and subarachnoid hemorrhage. These CBF monitoring techniques should be integrated with TCD and cerebral metabolism monitoring as described elsewhere in this issue. With further clinical experience and research and development in the area of neurosurgical critical care, CBF monitoring is almost certainly destined to become a routine and widely employed technique.

Craniocerebral trauma renders the brain vulnerable to a variety of secondary insults that must be prevented or promptly corrected before irreversible neurologic damage occurs. These secondary insults can include hypoxia, ischemia, or both, which result in significant cell loss. The trauma-induced state of vulnerability appears to be due to cellular ionic and metabolic alterations that make up the basic physiologic sequelae after brain injury. We discuss clinical aspects regarding these potentially devastating injuries in an effort to enhance their recognition and aid in their management.

Thirty patients admitted after suffering closed head injuries, with Glasgow Coma Scale scores ranging from 3 to 15, were evaluated with transcranial Doppler ultrasound monitoring. Blood flow velocity was determined in the middle cerebral artery (MCA) and the intracranial portion of the internal carotid artery (ICA) in all patients. Because proximal flow in the extracranial ICA declines in velocity when arterial narrowing becomes hemodynamically significant, the extracranial ICA velocity was concurrently monitored in 19 patients. To assess cerebral perfusion, cerebral blood flow (CBF) measurements obtained with the intravenous 133Xe technique were completed in 16 patients. Vasospasm, designated as MCA velocity exceeding 120 cm/sec, was found in eight patients (26.7%). Severe vasospasm, defined as MCA velocity greater than 200 cm/sec, occurred in three patients, and was confirmed by angiography in all three. Subarachnoid hemorrhage (SAH) was documented by computerized tomography in five (62.5%) of the eight patients with vasospasm. All cases of severe vasospasm were associated with subarachnoid blood. The time course of vasospasm in patients with traumatic SAH was similar to that found in patients with aneurysmal SAH; in contrast, arterial spasm not associated with SAH demonstrated an uncharacteristically short duration (mean 1.25 days), suggesting that this may be a different type of spasm. A significant correlation (p less than 0.05) was identified between the lowest CBF and highest MCA velocity in patients during the period of vasospasm, indicating that arterial narrowing can lead to impaired CBF. Ischemic brain damage was found in one patient who had evidence of cerebral infarction in the territories supplied by the arteries affected by spasm. These findings demonstrate that delayed cerebral arterial spasm is a frequent complication of closed head injury and that the severity of spasm is, in some cases, comparable to that seen in aneurysmal SAH. This experience suggests that vasospasm is an important secondary posttraumatic insult that is potentially treatable.

Cystic neoplasms of the pancreas can be easily misdiagnosed and mistreated by the surgeon unfamiliar with the pathology, natural history, and operative strategy specific to these uncommon tumors. The authors have treated nine patients over a seven-year period involving four cystadenocarcinomas, two mucinous cystadenomas, two serous cystadenomas, and one solid and papillary epithelial tumor. Our experience illustrates the inaccuracies in both clinical and pathologic diagnosis. Suspected cystic neoplasms are optimally managed by resection. Their slow growth and late metastasis permits curative surgery after a previous drainage or bypass procedure. An aggressive surgical approach is therefore warranted, and multimodal treatment with radiation and chemotherapy may be clinically applicable to large, invasive cystadenocarcinomas.

Staphylococcus aureus is the most frequently reported, though not the only, causative organism in children who have osteomyelitis. In an 11-year-old child with osteomyelitis of the calcaneus, the etiologic agent was identified as a Group B beta-hemolytic streptococcal organism. This organism seems not to have been previously reported as the cause of osteomyelitis in the heel.