Surgical treatment for chronic subdural hematoma in the elderly: A retrospective analysis.

Background: Chronic subdural hematoma (CSDH) is primarily a disease of the elderly. Less invasive interventions are often offered for elderly (> 80 years) patients due to concerns for elevated surgical risk, although data suggesting a clear outcome benefit is lacking. Methods: All patients aged 65 years or older who underwent surgical treatment for CSDH at a single institution over a 4-year period were evaluated in this retrospective analysis. Surgical options included twist drill craniostomy (TDC), burr hole craniotomy (BHC), or standard craniotomy (SC). Outcomes, demographics, and clinical data were collected. Practice patterns and outcomes for patients older than 80 years old were compared to the age 65-80 cohort. Results: 110 patients received TDC, 35 received BHC, and 54 received SC. There was no significant difference in post-operative complications, outcomes, or late recurrence (30-90 days). Recurrence at 30 days was significantly higher for TDC (37.3% vs. 2.9% vs 16.7%, p 80 group, SC had higher risk of stroke and increased length of stay. Conclusion: Twist drill craniostomy, burr hole craniostomy, and standard craniotomy have similar neurologic outcomes in elderly patients. Presence of thick membranes is a relative contra-indication for TDC due to high 30-day recurrence. Patients > 80 have higher risk of stroke and increased length of stay with SC.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Surgical Resection for the Treatment of Patients With Vestibular Schwannomas.

QUESTION 1: What surgical approaches for vestibular schwannomas (VS) are best for complete resection and facial nerve (FN) preservation when serviceable hearing is present? RECOMMENDATION: There is insufficient evidence to support the superiority of either the middle fossa (MF) or the retrosigmoid (RS) approach for complete VS resection and FN preservation when serviceable hearing is present. QUESTION 2: Which surgical approach (RS or translabyrinthine [TL]) for VS is best for complete resection and FN preservation when serviceable hearing is not present? RECOMMENDATION: There is insufficient evidence to support the superiority of either the RS or the TL approach for complete VS resection and FN preservation when serviceable hearing is not present. QUESTION 3: Does VS size matter for facial and vestibulocochlear nerve preservation with surgical resection? RECOMMENDATION: Level 3: Patients with larger VS tumor size should be counseled about the greater than average risk of loss of serviceable hearing. QUESTION 4: Should small intracanalicular tumors (<1.5 cm) be surgically resected? RECOMMENDATION: There are insufficient data to support a firm recommendation that surgery be the primary treatment for this subclass of VSs. QUESTION 5: Is hearing preservation routinely possible with VS surgical resection when serviceable hearing is present? RECOMMENDATION: Level 3: Hearing preservation surgery via the MF or the RS approach may be attempted in patients with small tumor size (<1.5 cm) and good preoperative hearing. QUESTION 6: When should surgical resection be the initial treatment in patients with neurofibromatosis type 2 (NF2)? RECOMMENDATION: There is insufficient evidence that surgical resection should be the initial treatment in patients with NF2. QUESTION 7: Does a multidisciplinary team, consisting of neurosurgery and neurotology, provides the best outcomes of complete resection and facial/vestibulocochlear nerve preservation for patients undergoing resection of VSs? RECOMMENDATION: There is insufficient evidence to support stating that a multidisciplinary team, usually consisting of a neurosurgeon and a neurotologist, provides superior outcomes compared to either subspecialist working alone. QUESTION 8: Does a subtotal surgical resection of a VS followed by stereotactic radiosurgery (SRS) to the residual tumor provide comparable hearing and FN preservation to patients who undergo a complete surgical resection? RECOMMENDATION: There is insufficient evidence to support subtotal resection (STR) followed by SRS provides comparable hearing and FN preservation to patients who undergo a complete surgical resection. QUESTION 9: Does surgical resection of VS treat preoperative balance problems more effectively than SRS? RECOMMENDATION: There is insufficient evidence to support either surgical resection or SRS for treatment of preoperative balance problems. QUESTION 10: Does surgical resection of VS treat preoperative trigeminal neuralgia more effectively than SRS? RECOMMENDATION: Level 3: Surgical resection of VSs may be used to better relieve symptoms of trigeminal neuralgia than SRS. QUESTION 11: Is surgical resection of VSs more difficult (associated with higher facial neuropathies and STR rates) after initial treatment with SRS? RECOMMENDATION: Level 3: If microsurgical resection is necessary after SRS, it is recommended that patients be counseled that there is an increased likelihood of a STR and decreased FN function. The full guideline can be found at: https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_8.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Imaging in the Diagnosis and Management of Patients With Vestibular Schwannomas.

QUESTION 1: What sequences should be obtained on magnetic resonance imaging (MRI) to evaluate vestibular schwannomas before and after surgery? TARGET POPULATION: Adults with vestibular schwannomas. RECOMMENDATIONS: Initial Preoperative Evaluation Level 3: Imaging used to detect vestibular schwannomas should use high-resolution T2-weighted and contrast-enhanced T1-weighted MRI. Level 3: Standard T1, T2, fluid attenuated inversion recovery, and diffusion weighted imaging MR sequences obtained in axial, coronal, and sagittal plane may be used for detection of vestibular schwannomas. Preoperative Surveillance Level 3: Preoperative surveillance for growth of a vestibular schwannoma should be followed with either contrast-enhanced 3-dimensional (3-D) T1 magnetization prepared rapid acquisition gradient echo (MPRAGE) or high-resolution T2 (including constructive interference in steady state [CISS] or fast imaging employing steady-state acquisition [FIESTA] sequences) MRI. Postoperative Evaluation Level 2: Postoperative evaluation should be performed with postcontrast 3-D T1 MPRAGE, with nodular enhancement considered suspicious for recurrence. QUESTION 2: Is there a role for advanced imaging for facial nerve detection preoperatively (eg, CISS/FIESTA or diffusion tensor imaging)? TARGET POPULATION: Adults with proven or suspected vestibular schwannomas by imaging. RECOMMENDATION: Level 3: T2-weighted MRI may be used to augment visualization of the facial nerve course as part of preoperative evaluation. QUESTION 3: What is the expected growth rate of vestibular schwannomas on MRI, and how often should they be imaged if a "watch and wait" philosophy is pursued? TARGET POPULATION: Adults with suspected vestibular schwannomas by imaging. RECOMMENDATION: Level 3: MRIs should be obtained annually for 5 yr, with interval lengthening thereafter with tumor stability. QUESTION 4: Do cystic vestibular schwannomas behave differently than their solid counterparts? TARGET POPULATION: Adults with vestibular schwannomas with cystic components. RECOMMENDATION: Level 3: Adults with cystic vestibular schwannomas should be counseled that their tumors may more often be associated with rapid growth, lower rates of complete resection, and facial nerve outcomes that may be inferior in the immediate postoperative period but similar to noncystic schwannomas over time. QUESTION 5: Should the extent of lateral internal auditory canal involvement be considered by treating physicians? TARGET POPULATION: Adult patients with vestibular schwannomas. RECOMMENDATION: Level 3: The degree of lateral internal auditory canal involvement by tumor adversely affects facial nerve and hearing outcomes and should be emphasized when interpreting imaging for preoperative planning. QUESTION 6: How should patients with neurofibromatosis type 2 (NF2) and vestibular schwannoma be imaged and over what follow-up period? TARGET POPULATION: Adult patients with NF2 and vestibular schwannomas. RECOMMENDATION: Level 3: In general, vestibular schwannomas associated with NF2 should be imaged (similar to sporadic schwannomas) with the following caveats: 1. More frequent imaging may be adopted in NF2 patients because of a more variable growth rate for vestibular schwannomas, and annual imaging may ensue once the growth rate is established. 2. In NF2 patients with bilateral vestibular schwannomas, growth rate of a vestibular schwannoma may increase after resection of the contralateral tumor, and therefore, more frequent imaging may be indicated, based on the nonoperated tumor's historical rate of growth. 3. Careful consideration should be given to whether contrast is necessary in follow-up studies or if high-resolution T2 (including CISS or FIESTA-type sequences) MRI may adequately characterize changes in lesion size instead. QUESTION 7: How long should vestibular schwannomas be imaged after surgery, including after gross-total, near-total, and subtotal resection? TARGET POPULATION: Adult patients with vestibular schwannomas followed after surgery. RECOMMENDATION: Level 3: For patients receiving gross total resection, a postoperative MRI may be considered to document the surgical impression and may occur as late as 1 yr after surgery. For patients not receiving gross total resection, more frequent surveillance scans are suggested; annual MRI scans may be reasonable for 5 yr. Imaging follow-up should be adjusted accordingly for continued surveillance if any change in nodular enhancement is demonstrated. The full guideline can be found at https://www.cns.org/guidelines/guidelines-management-patients-vestibular-schwannoma/chapter_5.

M6-C artificial disc placement.

There has been a steady evolution of cervical total disc replacement (TDR) devices over the last decade resulting in surgical technique that closely mimics anterior cervical discectomy and fusion as well as disc design that emphasizes quality of motion. The M6-C TDR device is a modern-generation artificial disc composed of titanium endplates with tri-keel fixation as well as a polyethylene weave with a polyurethane core. Although not yet approved by the FDA, M6-C has finished a pilot and pivotal US Investigational Device Exemption (IDE) study. The authors present the surgical technique for implantation of a 2-level M6-C cervical TDR device. The video can be found here: https://youtu.be/rFEAqINLRCo .

Automated generation and refinement of protein signatures: case study with G-protein coupled receptors.

MOTIVATION: Previous work had established that it was possible to derive sparse signatures (essentially sequence-length motifs) by examining points of contact between residues in proteins of known three-dimensional (3D) structure. Many interesting protein families have very little tertiary structural information. Methods for deriving signatures using only primary and secondary-structural information were therefore developed. RESULTS: Two methods for deriving protein signatures using protein sequence information and predicted secondary structures are described. One method is based on a scoring approach, the other on the Genetic Algorithm (GA). The effectiveness of the method was tested on the superfamily of GPCRs and compared with the established hidden Markov model (HMM) method. The signature method is shown to perform well, detecting 68% of superfamily members before the first false positive sequence and detecting several distant relationships. The GA population was used to provide information on alignment regions of particular importance for selection of key residues.