Severe Lacerations in Alpine Ski Racing: A Case Series and Review of the Literature.

STUDY DESIGN: Case series. LEVEL OF EVIDENCE: Level 4C.

Clinical Reasoning: A 67-Year-Old Woman With Abdominal Pain, Constipation, and Urinary Retention.

Meningeal melanocytomas are an extremely rare, pigmented tumors of the central nervous system (CNS). They generally carry a favorable prognosis, although recurrence and transformation into the more aggressive malignant melanoma has been reported. We present a case of a patient who reported constipation and abdominal pain around the umbilicus, which progressed into cord compression with lower extremity weakness and gait instability. Spinal magnetic resonance imaging (MRI) revealed a tumor at the level of T11, and she underwent gross total resection of the mass. Pathology demonstrated a meningeal melanocytoma with intermediate features. She received post-operative radiation therapy and had stable disease for three years, at which time she developed new weakness and drop metastases. This case represents a rare presentation of a rare disease, in which a spinal cord tumor presented with constipation and abdominal distress. Intradural-extramedullary tumors of the thoracic spine are most commonly nerve sheath tumors or meningiomas, but rare entities such as melanocytomas can present in this location; even more rarely, these tumors can have an aggressive course with delayed recurrence.

Differential Patterns of Referral to Neurosurgery: A Comparison of Allopathic Physicians, Osteopathic Physicians, Nurse Practitioners, Physician Assistants, and Chiropractors.

BACKGROUND: Rising cost and limited resources remain major challenges to U.S. health care and neurosurgery in particular. To ensure an efficient and cost-effective health care system, it is important that referrals to neurosurgery clinics are appropriate, and that referred patients have a reasonably high probability of requiring surgical intervention or, at a minimum, ongoing neurosurgical follow-up. This retrospective study tests the null hypothesis that the probability of a referred patient requiring surgery is independent of referring provider credentials and referring service specialty. METHODS: A database of all patients referred to the neurosurgery clinic from 2015 through 2018 (n = 5677) was reviewed; the database included referring provider, referring provider specialty, number of subsequent clinic visits, and outcome of surgery or no surgery. Associations between categorical variables were tested using a χ2 analysis with post hoc relative risk (RR) calculations and binary logistical regression. RESULTS: Compared with patients referred by allopathic physicians, patients referred by osteopathic physicians (RR, 0.63; 95% confidence interval [CI], 0.48-0.84) and those referred by nurse practitioners (RR, 0.66; 95% CI, 0.51-0.86) were significantly less likely to require surgery. Probability of surgical intervention also varied by referrer specialty. Patients referred by neurologists required surgery 35% of the time, whereas patients referred by family practitioners required surgery 19% of the time, and patients referred by pediatricians required surgery only 7% of the time (P < 0.01). Binary logistic regression revealed that referrals from nurse practitioners and osteopathic physicians were independently associated with a decreased probability of surgical intervention. CONCLUSIONS: Our data strengthen the concept of having interdisciplinary teams led by physicians at the primary care level to ensure appropriate referrals. Training and adherence to guidelines must continually be reinforced to ensure proper referrals.

Increased rate of complications on a neurological surgery service after implementation of the Accreditation Council for Graduate Medical Education work-hour restriction.

OBJECT: The Accreditation Council for Graduate Medical Education instituted mandatory 80-hour work-week limitations in July 2003. The work-hour restriction was met with skepticism among the academic neurosurgery community and is thought to represent a barrier to teaching, ultimately compromising patient care. The authors hypothesize that the introduction of the mandatory resident work-hour restriction corresponds with an overall increase in morbidity rate. METHODS: This study compares the morbidity and mortality rates on an academic neurological surgery service before and after institution of the work-hour restriction. Complications are individually assessed at a monthly divisional conference by neurosurgical faculty and residents. A prospective database was commenced in July 2000 recording all complications, complications that were deemed to be potentially avoidable ("possibly preventable"), and complications that were deemed unavoidable. The incidence of morbidity and mortality from July 2000 to June 2003 is compared with the incidence from July 2003 to June 2006. RESULTS: The overall rate of morbidity and mortality increased from 103 to 114 per 1000 patients treated after institution of the work-hour restriction, although this increase was not statistically significant (χ(2)(1, N = 8546) = 2.6, p = 0.106). The morbidity rate increased from 70 to 89 per 1000 patients treated after institution of the work-hour restriction (χ(2)(1, N = 8546) = 10, p = 0.001). The overall mortality rate was diminished from 32 to 27 per 1000 patients treated after institution of the work-hour restriction (χ(2)(1, N = 8546) = 3.2, p = 0.075). Morbidities considered avoidable or possibly preventable were seen to increase from 56 to 66 per 1000 patients treated (χ(2)(1, N = 8546) = 5.7, p = 0.017). Avoidable or possibly preventable mortalities numbered 3 per 1000 patients treated, and this rate did not change after introduction of the work-hour restriction (χ(2)(1, N = 8546) = 0.08, p = 0.777). CONCLUSIONS: The morbidity rate on a neurological surgery service is increased after implementation of the work-hour restriction. Mortality rates remain unchanged.

Spinal injury patterns among skiers and snowboarders.

OBJECT: Skiing and snowboarding injuries have increased with the popularity of these sports. Spinal cord injuries (SCIs) are a rare but serious event, and a major cause of morbidity and mortality for skiers and snowboarders. The purpose of this study is to characterize the patterns of SCI in skiers and snowboarders. METHODS: The authors queried the Nationwide Inpatient Sample for the years 2000-2008 for all patients admitted with skiing or snowboarding as the mechanism of injury, yielding a total of 8634 patients. The injury patterns were characterized by the ICD-9 diagnostic and procedure codes. The codes were searched for those pertaining to vertebral and skull fracture; spinal cord, chest, abdominal, pelvic, and vessel injuries; and fractures and dislocations of the upper and lower extremity. Statistical analysis was performed with ANOVA and Student t-test. RESULTS: Patients were predominantly male (71%) skiers (61%), with the average age of the skiers being older than that of snowboarders (39.5 vs 23.5 years). The average length of stay for patients suffering from spine trauma was 3.8 days and was increased to 8.9 days in those with SCI. Among hospitalized patients, SCI was seen in 0.98% of individuals and was equally likely to occur in snowboarders and skiers (1.07% vs 0.93%, p < 0.509). Cervical spine trauma was associated with the highest likelihood of SCI (19.6% vs. 10.9% of thoracic and 6% of lumbar injuries, p < 0.0001). Patients who were injured skiing were more likely to sustain a cervical spine injury, whereas those injured snowboarding had higher frequencies of injury to the lumbar spine. The most common injury seen in tandem with spine injury was closed head injury, and it was seen in 13.4% of patients. Conversely, a spine injury was seen in 12.9% of patients with a head injury. Isolated spine fractures were seen in 4.6% of patients. CONCLUSIONS: Skiers and snowboarders evaluated at the hospital are equally likely to sustain spine injuries. Additionally, participants in both sports have an increased incidence of SCI with cervical spine trauma.

Helmet use and reduction in skull fractures in skiers and snowboarders admitted to the hospital.

OBJECT: Helmet use has been associated with fewer hospital visits among injured skiers and snowboarders, but there remains no evidence that helmets alter the intracranial injury patterns. The authors hypothesized that helmet use among skiers and snowboarders reduces the incidence of head injury as defined by findings on head CT scans. METHODS: The authors performed a retrospective review of head-injured skiers and snowboarders at 2 Level I trauma centers in New England over a 6-year period. The primary outcome of interest was intracranial injury evident on CT scans. Secondary outcomes included the following: need for a neurosurgical procedure, presence of spine injury, need for ICU admission, length of stay, discharge location, and death. RESULTS: Of the 57 children identified who sustained a head injury while skiing or snowboarding, 33.3% were wearing a helmet at the time of injury. Of the helmeted patients, 5.3% sustained a calvarial fracture compared with 36.8% of the unhelmeted patients (p = 0.009). Although there was a favorable trend, there was no significant difference in the incidence of epidural hematoma, subdural hematoma, intraparenchymal hemorrhage, subarachnoid hemorrhage, or contusion in helmeted and unhelmeted patients. With regard to secondary outcomes, there were no significant differences between the 2 groups in percentage of patients requiring neurosurgical intervention, percentage requiring admission to an ICU, total length of stay, or percentage discharged home. There was no difference in the incidence of cervical spine injury. There was 1 death in an unhelmeted patient, and there were no deaths among helmeted patients. CONCLUSIONS: Among hospitalized children who sustained a head injury while skiing or snowboarding, a significantly lower number of patients suffered a skull fracture if they were wearing helmets at the time of the injury.

Inhibition of Ca++ sparks by oxyhemoglobin in rabbit cerebral arteries.

OBJECT: Oxyhemoglobin (HbO2) causes cerebral artery constriction and is one component of blood that likely contributes to the pathogenesis of cerebral vasospasm after aneurysm rupture. This study was designed to examine the acute effect of HbO2 on subcellular Ca(++) release events (Ca(++) sparks) in cerebral artery myocytes. Calcium sparks provide a tonic hyperpolarizing and relaxing influence to vascular smooth muscle by the activation of plasmalemmal large-conductance Ca(++)-activated K+ channels. Evidence is provided that HbO2 may contract cerebral vascular muscle in part by free radical-mediated inhibition of Ca(++) sparks. METHODS: Calcium sparks were visualized in intact pressurized rabbit cerebral arteries by using laser scanning confocal microscopy and a Ca(++) indicator dye. Calcium spark frequency was reduced by approximately 65% after a 15-minute application of HbO2 (10(-4) M). The HbO2-induced decrease in Ca(++) spark frequency was prevented by a combination of the free radical scavengers superoxide dismutase and catalase. Isometric force measurements were used to characterize the role of the vascular endothelium and smooth-muscle Ca(++) channels in HbO2-induced cerebral artery contraction. The HbO2-induced contractions were independent of the vascular endothelium, but were abolished by diltiazem, a blocker of L-type voltage-dependent Ca(++) channels (VDCCs). Ryanodine, a blocker of ryanodine-sensitive Ca(++) release channels located on the sarcoplasmic reticulum, also reduced HbO2-induced contractions by approximately 50%. CONCLUSIONS: These results support the hypothesis that HbO2 may contract cerebral artery segments in part by inhibition of Ca(++) sparks, leading to decreased large-conductance Ca(++)-activated K+ channel activity, membrane potential depolarization, and enhanced Ca(++) entry through VDCCs.

Molecular mechanisms of Triple H therapy in the treatment of SAH-induced vasospasm / 第三军医大学学报

Objective Cerebral artery vasospasm is a major cause of death and disability in patients experiencing subarachnoid hemorrhage (SAH). Vasospasm typically has been evaluated using angiography to examine narrowing of large diameter (>1 mm) cerebral arteries. Currently, little is known regarding the impact of SAH on small diameter (100～200 μm) cerebral arteries, which play an important role in the autoregulation of cerebral blood flow. The goal of the current study was to examine the influence of SAH on the pressure-diameter relationship of these small diameter blood vessels. Methods Small diameter cerebral arteries were obtained from a rabbit SAH model. Isolated artery segments were canulated and placed in a myograph chamber superfused with warmed, oxygenated, physiological saline solution. Diameter measurements were then recorded to step-wise increases in intravascular pressure. Results Cerebral arteries from SAH animals exhibited a significant increase in pressure-induced constrictions (myogenic tone) at intravascular pressures between 40 mmHg and 120 mmHg. At intravascular pressures above 120 mmHg, myogenic tone began to decrease and was abolished at pressures above 180 mmHg. Conclusion These data suggest that in the days following SAH, myogenic tone is enhanced in small diameter cerebral arteries subjected to physiological levels of intravascular pressure. However, supra-physiological intravascular pressures causes vasodilation, suggesting small diameter cerebral arteries may act as therapeutic targets of hypervolemia, hemodilution, and hypertension "Triple H therapy" used in the treatment of cerebral artery vasospasm.

Molecular mechanisms of Triple H therapy in the treatment of SAH-induced vasospasm / 第三军医大学学报

Objective Cerebral artery vasospasm is a major cause of death and disability in patients experiencing subarachnoid hemorrhage (SAH). Vasospasm typically has been evaluated using angiography to examine narrowing of large diameter (>1 mm) cerebral arteries. Currently, little is known regarding the impact of SAH on small diameter (100～200 μm) cerebral arteries, which play an important role in the autoregulation of cerebral blood flow. The goal of the current study was to examine the influence of SAH on the pressure-diameter relationship of these small diameter blood vessels. Methods Small diameter cerebral arteries were obtained from a rabbit SAH model. Isolated artery segments were canulated and placed in a myograph chamber superfused with warmed, oxygenated, physiological saline solution. Diameter measurements were then recorded to step-wise increases in intravascular pressure. Results Cerebral arteries from SAH animals exhibited a significant increase in pressure-induced constrictions (myogenic tone) at intravascular pressures between 40 mmHg and 120 mmHg. At intravascular pressures above 120 mmHg, myogenic tone began to decrease and was abolished at pressures above 180 mmHg. Conclusion These data suggest that in the days following SAH, myogenic tone is enhanced in small diameter cerebral arteries subjected to physiological levels of intravascular pressure. However, supra-physiological intravascular pressures causes vasodilation, suggesting small diameter cerebral arteries may act as therapeutic targets of hypervolemia, hemodilution, and hypertension "Triple H therapy" used in the treatment of cerebral artery vasospasm.

Molecular mechanisms of Triple H therapy in the treatment of SAH-induced vasospasm / 第三军医大学学报

Objective Cerebral artery vasospasm is a major cause of death and disability in patients experiencing subarachnoid hemorrhage (SAH). Vasospasm typically has been evaluated using angiography to examine narrowing of large diameter (>1 mm) cerebral arteries. Currently, little is known regarding the impact of SAH on small diameter (100～200 μm) cerebral arteries, which play an important role in the autoregulation of cerebral blood flow. The goal of the current study was to examine the influence of SAH on the pressure-diameter relationship of these small diameter blood vessels. Methods Small diameter cerebral arteries were obtained from a rabbit SAH model. Isolated artery segments were canulated and placed in a myograph chamber superfused with warmed, oxygenated, physiological saline solution. Diameter measurements were then recorded to step-wise increases in intravascular pressure. Results Cerebral arteries from SAH animals exhibited a significant increase in pressure-induced constrictions (myogenic tone) at intravascular pressures between 40 mmHg and 120 mmHg. At intravascular pressures above 120 mmHg, myogenic tone began to decrease and was abolished at pressures above 180 mmHg. Conclusion These data suggest that in the days following SAH, myogenic tone is enhanced in small diameter cerebral arteries subjected to physiological levels of intravascular pressure. However, supra-physiological intravascular pressures causes vasodilation, suggesting small diameter cerebral arteries may act as therapeutic targets of hypervolemia, hemodilution, and hypertension "Triple H therapy" used in the treatment of cerebral artery vasospasm.