Image-localized biopsy mapping of brain tumor heterogeneity: A single-center study protocol.

Brain cancers pose a novel set of difficulties due to the limited accessibility of human brain tumor tissue. For this reason, clinical decision-making relies heavily on MR imaging interpretation, yet the mapping between MRI features and underlying biology remains ambiguous. Standard (clinical) tissue sampling fails to capture the full heterogeneity of the disease. Biopsies are required to obtain a pathological diagnosis and are predominantly taken from the tumor core, which often has different traits to the surrounding invasive tumor that typically leads to recurrent disease. One approach to solving this issue is to characterize the spatial heterogeneity of molecular, genetic, and cellular features of glioma through the intraoperative collection of multiple image-localized biopsy samples paired with multi-parametric MRIs. We have adopted this approach and are currently actively enrolling patients for our 'Image-Based Mapping of Brain Tumors' study. Patients are eligible for this research study (IRB #16-002424) if they are 18 years or older and undergoing surgical intervention for a brain lesion. Once identified, candidate patients receive dynamic susceptibility contrast (DSC) perfusion MRI and diffusion tensor imaging (DTI), in addition to standard sequences (T1, T1Gd, T2, T2-FLAIR) at their presurgical scan. During surgery, sample anatomical locations are tracked using neuronavigation. The collected specimens from this research study are used to capture the intra-tumoral heterogeneity across brain tumors including quantification of genetic aberrations through whole-exome and RNA sequencing as well as other tissue analysis techniques. To date, these data (made available through a public portal) have been used to generate, test, and validate predictive regional maps of the spatial distribution of tumor cell density and/or treatment-related key genetic marker status to identify biopsy and/or treatment targets based on insight from the entire tumor makeup. This type of methodology, when delivered within clinically feasible time frames, has the potential to further inform medical decision-making by improving surgical intervention, radiation, and targeted drug therapy for patients with glioma.

Right radial nerve decompression for refractory radial tunnel syndrome.

BACKGROUND: Radial tunnel syndrome arises due to compression of the radial nerve through the radial tunnel.[1,5] The radial nerve divides into superficial and deep branches in the forearm. The deep branch travels posteriorly through the heads of the supinator where compression commonly occurs.[3,9,7] This syndrome results in pain in the hand and forearm with no motor weakness.[8] This condition can be treated conservatively with splinting and anti-inflammatory medication.[2,4,6] For cases of refractory radial tunnel syndrome, surgical management can be considered. Herein, we have presented a step-by-step video guide on how to perform a radial nerve decompression with a review of the relevant anatomy and surgical considerations. CASE DESCRIPTION: A 68-year-old right-handed woman presented to the Mayo Clinic (Scottsdale, AZ) with the right elbow pain which radiated to the forearm causing significant difficulties with daily tasks. She had been dealing with worsening symptoms for 4 months. The patient's history of gardening and clinical presentation allowed for diagnosis of radial tunnel syndrome. After conservative measures failed and other differential diagnoses were excluded, surgical decompression was recommended to treat her symptoms. The patient's right arm was marked preoperatively between the brachioradialis and extensor carpi radialis longus (ECRL) muscles. The posterior cutaneous nerve of the forearm was identified which allowed for the determination of the interval between the brachioradialis and ECRL. Separation of the two muscles allowed for the identification of the radial sensory nerve. A nerve stimulator was used to confirm the sensory nature of this nerve. The nerve to the extensor carpi radialis brevis (ECRB) was identified and retracted with a vessel loop. Dorsal to the nerve to the ECRB is the posterior interosseous nerve (PIN), which was identified and retracted with a vessel loop. The fascia of the ECRB was divided both longitudinally and transversely and the supinator below was identified. The supinator muscle was carefully divided to further decompress the PIN. Informed consent for publication of this material was obtained from the patient. CONCLUSION: The patient tolerated the procedure well and reported significantly reduced pain at 7-month follow-up. To the best of our knowledge, video tutorials on this procedure have not been published. This video can serve as an educational guide for peripheral nerve specialists dealing with similar lesions.

Current Parental Leave Policies for Medical Students at U.S. Medical Schools: A Comparative Study.

PURPOSE: Parental leave for new parents is essential as they adjust to the physical and psychological changes that accompany childbirth and caring for a newborn. This study sought to determine the current state of parental leave policies for medical students at medical schools in the United States. METHOD: From November to December 2019, 2 researchers independently reviewed the websites of 199 U.S. MD-granting and DO-granting medical schools (including in U.S. territories). Online student handbooks and school webpages were searched for the following keywords: "pregnant" OR "pregnancy" OR "maternity" OR "parent" OR "family" OR "child" OR "birth." Data were analyzed using descriptive statistics. Fisher's exact tests evaluated differences in proportion by group. RESULTS: Of 199 schools, 65 (32.66%) had parental leave policies available online or in the handbook: 39 of 155 (25.16%) MD-granting and 26 of 44 (59.09%) DO-granting schools. Of those policies, 59 (90.77%) were included in the student handbook. Most policies (28, 43.08%) were included as an option within the school's general leave of absence policy. Both parents were included in 38 (58.46%) policies; 23 (35.38%) policies mentioned only mothers; and 4 (6.15%) were unknown. An option to maintain original graduation date was offered in 21 (32.1%) schools' policies. Three schools (4.62%) included adoption as qualifying for parental leave. When comparing MD and DO programs, DO programs were statistically more likely to have a parental leave policy: 39 (25.16%) vs 26 (59.09%); P < .001. CONCLUSIONS: Balancing medical school with pregnancy and childbirth necessitates administrative support to address the inherent scheduling challenges. Currently, many schools lack parental leave policies for medical students that are easily accessible, are separate from formal leaves of absence, allow for at least 12 weeks, and are tailored to the student academic year to ensure on-time completion of medical education.

Differences by Practice Year in Numbers of U.S. Female Neurosurgeons.

OBJECTIVE: We sought to determine the proportion and number of female neurosurgeons in the workforce at different stages of practice. METHODS: The Physician Compare National Downloadable File data set was obtained from the Centers for Medicare & Medicaid Services for physicians who indicated "neurosurgery" as their primary specialty. Physician duplicates, physicians with no listed medical school graduation year, and physicians expected to be in residency (graduation years 2013-2019) were removed, yielding 4956 neurosurgeons. Five-year intervals were used to measure the number of male and female neurosurgeons by different stages of their careers. For example, graduates from years 2008-2012 were expected to be in their first 1-5 years of practice. RESULTS: There were 405 female (8.2%) and 4551 male (91.8%) neurosurgeons. At 1-5 years of practice, 13.8% (105/760) were women; 6-10 years, 11.5% (94/820) women; 11-15 years, 8.9% (64/720) women; 16-20 years, 8.7% (59/682) women; 21-25 years, 7.4% (46/619) women; 26-30 years, 3.8% (20/520) women; 31-35 years, 3.6% (15/413) women; and 36 years or more, 0.5% women (2/422). The number of female neurosurgeons varied among states, ranging from 0 in Hawaii to 53 in California. The states with the lowest percentage of female neurosurgeons were Hawaii (0%), Oklahoma (3.1%), and Nevada (3.6%). The states with the highest percentage of female neurosurgeons were New Hampshire (20.0%), Vermont (16.7%), and Rhode Island (15.8%). CONCLUSIONS: The number of practicing female neurosurgeons within the United States is increasing, as shown by the growing percentage of women who are earlier in their surgical careers.

A Rare Intracranial Collision Tumor of Meningioma and Metastatic Uterine Adenocarcinoma: Case Report and Literature Review.

BACKGROUND: A collision tumor is a rare entity consisting of 2 histologically distinct tumor types (benign or malignant) in the same anatomic location. This can occur from a tumor-to-tumor metastasis or as a result of 2 adjacent intracranial tumors colliding and growing together. To our knowledge, this is the first reported case of collision tumor with confirmed meningioma and uterine adenocarcinoma. Multiple mechanisms have been proposed for the facilitative growth of collision tumors, including local epigenetic signaling. Clinically, it is important to consider collision tumors in the differential diagnosis of a rapidly growing intracranial lesion in the setting of systemic cancer to provide optimal surgical and postoperative management. CASE DESCRIPTION: A 78-year-old, right-handed woman with a known 10-year history of stable meningioma presented for evaluation of a right sphenoid wing lesion. She had recently completed treatment of uterine papillary serous carcinoma with no evidence of disease on follow-up imaging. On presentation, there was significant progression of the meningioma resulting in brain compression and right third nerve palsy. The patient underwent urgent resection of the lesion. Pathology demonstrated a collision tumor with a combination of metastatic uterine papillary serous carcinoma and meningioma. CONCLUSIONS: It is important to consider a collision tumor when a patient with a benign intracranial lesion presents with rapid progression, even in the context of a systemic cancer that rarely metastasizes to the brain. Appropriate histopathologic assessment is crucial in these cases and can have a significant impact on treatment plan and prognosis.

Retrospective radiographic analysis of anterior lumbar fusion for high grade lumbar spondylolisthesis.

BACKGROUND: High-grade spondylolisthesis (>50% slippage) is infrequently encountered in adults and frequently requires surgical treatment. The optimal surgical treatment is controversial with limited literature guidance as to optimal approach to treatment. An observational study to examine the technique and radiographic outcomes of adult patients treated with anterior lumbar interbody fusion (ALIF) and posterior percutaneous instrumentation for high-grade spondylolisthesis. METHODS: ALIF was performed in 5 consecutive patients (3/5 female, 2/5 male) aged 29-67 years old who presented with low back pain and L5 radiculopathy. All patients failed conservative treatment and were treated with L4-5 and L5-S1 ALIF followed by posterior percutaneous L4-S1 pedicle screw and rod fixation. Pre- and postoperative clinical data was collected including L5-S1 posterior disk height in millimeters, millimeters of spondylolisthesis at L5-S1, degrees of segmental lordosis (L4-S1), lumbar lordosis (L1-S1), and lumbar lordosis pelvic incidence (LL-PI) mismatch. RESULTS: Six weeks following surgery, no patient reported residual L5 radicular symptoms. At last follow up, patient satisfaction, according to Modified Macnab Criteria, was excellent in 4/5 patients and good in 1/5 patient. In the 4 patients with greater than 1 year radiographic follow up, fusion rate was 100% on computed tomography (CT). Mean increase in posterior disk height was 12.5 mm (range, 11.4-13.5 mm). Mean reduction in spondylolisthesis was 58.7% (range, 20.2-100%). Mean segmental (L4-S1) and overall (L1-S1) lumbar lordosis increased by 23.6% (range, 6.5-41.7%) and 16.6% (2.5-31.5%), respectively. Following surgery, LL-PI mismatch decreased from a mean of 16.4 to 10.2 degrees. CONCLUSIONS: ALIF with posterior percutaneous instrumentation is a safe and effective treatment for high-grade lumbosacral spondylolisthesis in properly selected adults. This technique improves lumbar sagittal parameters and reduces spondylolisthesis. The indirect neural decompression from simultaneous disk height restoration and spondylolisthesis reduction may be associated with lower neurological injury rate compared to posterior-only. Future prospective study is needed to validate this hypothesis.

Use of transparent plastic tubular retractor in surgery for deep brain lesions: a case series.

Brain tissue retraction is frequently required to reach deep intra-axial lesions, and the quest for an ideal retractor that would protect the underlying brain tissue continues. Despite the availability of multiple retractors, the incidence of brain retraction injury remains high and has been reported to be 5% to 10%. A recently developed transparent tubular retractor appears to provide several advantages in surgery for deep intra-axial tumors and intracerebral hematomas. We used a new commercially available transparent tubular retractor in 16 craniotomies. Fourteen of these patients were operated upon for deep tumors and cysts, including two intraventricular tumors and two for deep intracerebral hemorrhages. In all patients, the tubular retractor was directed toward the lesion through a small corticotomy and guided by a navigation system. Each lesion was completely removed through the retractor's lumen. In all cases, the tubular retractors provided excellent visualization of the underlying pathology and facilitated its surgical removal, dissection, and hemostasis. The tubular nature of the retractor allowed the rotation and changing the angle of approach without putting extra pressure on the brain tissue, which inevitably occurs when malleable or other ribbon-type retractors are used. There were no hematomas on routine postoperative CT scans in this series. Transparent tubular retractors provide a unique means of deep visualization and even force distribution at the retracted brain tissue. Although these retractors were originally designed for the removal of deep subcortical tumors, they may be used to access and evacuate intracerebral hematomas. In our experience, the use of tubular retractors allows one to achieve safe access to deep intracerebral lesions and decreases the rate of retraction-related complications.

Clinical and functional outcomes of laminoplasty and laminectomy.

OBJECTIVE: Laminoplasty has become a common alternative to laminectomy for cervical spondylotic myelopathy or radiculopathy. The procedures have been compared before, but data on functional recovery are limited. We aim to compare the safety and short-term clinical and functional outcomes of cervical laminoplasty and cervical laminectomy. METHODS: We performed a retrospective analysis of the outcome of 72 patients who had laminoplasty and 49 patients who had laminectomy at our hospital from 1999 to 2005. Patients had cervical spondylotic myelopathy or radiculopathy. All of the patients were similar in age and pre-operative functional status. All patients were assessed pre-operatively and 4 months post-operatively with the Rankin disability score, Glasgow outcome scale and Karnofsky and Nurick scales. RESULTS: Laminoplasty resulted in greater improvement than laminectomy on the Rankin scale (p<0.0001, chi-square test), GOS (p<0.0027, chi-square test) and Karnofsky scores (p<0.01, Wilcoxon test). Nurick scores improved in both groups without a significant difference (p<0.62, Wilcoxon test). The proportion of patients who improved on all scales tended to be greater in the laminoplasty group. Patients spent 1.8 fewer days in the hospital after laminoplasty (p=0.04, Wilcoxon rank-sum test). There was no mortality or permanent morbidity for either procedure. CONCLUSION: Both cervical laminectomy and laminoplasty are safe and effective for the treatment of cervical myelopathy or radiculopathy. Cervical laminoplasty results in a shorter hospital stay and greater functional improvement at 4 months follow-up.

Subacute subdural hematoma in a 45-year-old woman with no significant past medical history after a roller coaster ride.

Amusement park ride injuries have been newsworthy events for many years. The multitude and severity of these injuries has been reported many times over the past 20 years and includes spinal cord and vertebral injuries, subarachnoid hemorrhage, internal and vertebral artery dissections, and even a few cases of subdural hematoma (SDH). There has also been as many theories to explain these injuries as there have been injuries themselves including how G forces and rotational acceleration can cause both neuroparenchymal and neurovascular injury.