Ethical Issues in Intraoperative Neuroscience Research: Assessing Subjects' Recall of Informed Consent and Motivations for Participation.

BackgroundAn increasing number of studies utilize intracranial electrophysiology in human subjects to advance basic neuroscience knowledge. However, the use of neurosurgical patients as human research subjects raises important ethical considerations, particularly regarding informed consent and undue influence, as well as subjects' motivations for participation. Yet a thorough empirical examination of these issues in a participant population has been lacking. The present study therefore aimed to empirically investigate ethical concerns regarding informed consent and voluntariness in Parkinson's disease patients undergoing deep brain stimulator (DBS) placement who participated in an intraoperative neuroscience study.MethodsTwo semi-structured 30-minute interviews were conducted preoperatively and postoperatively via telephone. Interviews assessed participants' motivations for participation in the parent intraoperative study, recall of information presented during the informed consent process, and participants' postoperative reflections on the research study.ResultsTwenty-two participants (mean age = 60.9) completed preoperative interviews at a mean of 7.8 days following informed consent and a mean of 5.2 days prior to DBS surgery. Twenty participants completed postoperative interviews at a mean of 5 weeks following surgery. All participants cited altruism or advancing medical science as "very important" or "important" in their decision to participate in the study. Only 22.7% (n = 5) correctly recalled one of the two risks of the study. Correct recall of other aspects of the informed consent was poor (36.4% for study purpose; 50.0% for study protocol; 36.4% for study benefits). All correctly understood that the study would not confer a direct therapeutic benefit to them.ConclusionEven though research coordinators were properly trained and the informed consent was administered according to protocol, participants demonstrated poor retention of study information. While intraoperative studies that aim to advance neuroscience knowledge represent a unique opportunity to gain fundamental scientific knowledge, improved standards for the informed consent process can help facilitate their ethical implementation.

Focused Ultrasound Thalamotomy with Dentato-Rubro-Thalamic Tractography in Patients with Spinal Cord Stimulators and Cardiac Pacemakers.

Magnetic resonance image-guided high-intensity focused ultrasound (MRgFUS)-based thermal ablation of the ventral intermediate nucleus of the thalamus (VIM) is a minimally invasive treatment modality for essential tremor (ET). Dentato-rubro-thalamic tractography (DRTT) is becoming increasingly popular for direct targeting of the presumed VIM ablation focus. It is currently unclear if patients with implanted pulse generators (IPGs) can safely undergo MRgFUS ablation and reliably acquire DRTT suitable for direct targeting. We present an 80-year-old male with a spinal cord stimulator (SCS) and an 88-year-old male with a cardiac pacemaker who both underwent MRgFUS for medically refractory ET. Clinical outcomes were measured using the Clinical Rating Scale for Tremor (CRST). DRTT was successfully created and imaging parameter adjustments did not result in any delay in procedural time in either case. In the first case, 7 therapeutic sonications were delivered. The patient improved immediately and durably with a 90% CRST-disability improvement at 6-week follow-up. In our second case, 6 therapeutic sonications were delivered with durable, 75% CRST-disability improvement at 6 weeks. These are the first cases of MRgFUS thalamotomy in patients with IPGs. DRTT targeting and MRgFUS-based thermal ablation can be safely performed in these patients using a 1.5-T MRI.

Surgical Treatment of Flat Back Syndrome With Anterior Hyperlordotic Cages.

BACKGROUND: Traditional correction for flat back syndrome is performed with a posterior-based surgery or combined approaches in revision cases. OBJECTIVE: To evaluate outcome from anterior surgery with the use of hyperlordotic cages (HLCs) in patients with flat back syndrome. METHODS: All patients operated with or without prior posterior lumbar surgery were studied. Pre- to postoperative sagittal alignment was analyzed. Radiographic parameters were analyzed including T1 pelvic angle (T1PA), sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), sacral slope (SS), pelvic incidence and lumbar lordosis (PI-LL), and T4-12TK. RESULTS: All 50 patients (mean age of 58 yr, 72% female with mean body mass index of 28) demonstrated significant radiographic alignment difference in their spinopelvic and global parameters from pre- to postoperative standing: LL (-37.04° vs -59.55°, P < .001), SS (35.12 vs 41.13, P < .001), PI-LL (23.55 vs 6.46), T4-12 TK (30.59 vs 41.67), PT (28.22 vs 22.13), SVA in mm (80.94 vs 37.39), and T1PA (28.70° vs 18.43°, P < .001). Using linear regression analysis, predicted pre- to postoperative change in standing LL corresponded to a pre- to postoperative changes in standing PI-LL mismatch, T1PA, TK, SS, PT, and SVA (R2 = 0.59, 0.38, 0.25, 0.16, 0.12, and 0.17, respectively). Five degrees of pre- to postoperative change in T1PA translates to -4.15° change in LL. CONCLUSION: Anterior surgery with HLCs followed by posterior instrumentation is an effective technique to treat flat back syndrome. HLCs are effective to maximize LL up to 30°, which is equivalent in magnitude to a pedicle subtraction osteotomy, but associated with less blood loss, quicker recovery, lower complications, and good surgical outcome.

Growth of Lumbosacral Perineural (Tarlov) Cysts: A Natural History Analysis.

BACKGROUND: Tarlov cysts (TC) are commonly found spinal perineural cysts. Symptomatic TCs are rare, however, and there is no consensus on their pathogenesis and optimal management. OBJECTIVE: To characterize cyst growth in patients with symptomatic TCs. METHODS: This is a retrospective cohort study of 28 subjects, evaluated for symptomatic TCs (2011-2017). Each of the subjects had multiple magnetic resonance imaging (MRIs) across time and was included in a natural history analysis. RESULTS: A total of 42 TCs were identified across the 28 subjects, of which 7 cysts (17%) across 5 subjects demonstrated growth. Across a mean follow-up of 4.7 ± 1.8 years, TCs grew at a relative rate of 2.9 ± 2.6% in the anteroposterior, 4.3 ± 3.8% in the craniocaudal, and 1.4 ± 1.4% in the transverse dimensions per year. None of the cysts decreased in size between successive MRIs. Symptoms of cerebrospinal fluid (CSF) hypotension (positional headaches) were positive predictors of prior cyst growth on logistic regression (P = 0.02, odds ratio = 10). A total of 2 of the 5 subjects were initially asymptomatic from their TCs, and developed symptoms during the period of cyst growth, whereas 2 others experienced worsening of their symptoms during cyst growth. CONCLUSION: We report on the growth of TCs, which is consistent with a widely-held theory that hydrostatic and pulsatile forces of CSF along with a ball-valve phenomenon allow for continuous dilation of TCs.

Outcomes of stereotactic radiosurgery for pilocytic astrocytoma: an international multiinstitutional study.

OBJECTIVE: The current standard initial therapy for pilocytic astrocytoma is maximal safe resection. Radiation therapy is considered for residual, recurrent, or unresectable pilocytic astrocytomas. However, the optimal radiation strategy has not yet been established. Here, the authors describe the outcomes of stereotactic radiosurgery (SRS) for pilocytic astrocytoma in a large multiinstitutional cohort. METHODS: An institutional review board-approved multiinstitutional database of patients treated with Gamma Knife radiosurgery (GKRS) between 1990 and 2016 was queried. Data were gathered from 9 participating International Radiosurgery Research Foundation (IRRF) centers. Patients with a histological diagnosis of pilocytic astrocytoma treated using a single session of GKRS and with at least 6 months of follow-up were included in the analysis. RESULTS: A total of 141 patients were analyzed in the study. The median patient age was 14 years (range 2-84 years) at the time of GKRS. The median follow-up was 67.3 months. Thirty-nine percent of patients underwent SRS as the initial therapy, whereas 61% underwent SRS as salvage treatment. The median tumor volume was 3.45 cm3. The tumor location was the brainstem in 30% of cases, with a nonbrainstem location in the remainder. Five- and 10-year overall survival rates at the last follow-up were 95.7% and 92.5%, respectively. Five- and 10-year progression-free survival (PFS) rates were 74.0% and 69.7%, respectively. On univariate analysis, an age < 18 years, tumor volumes < 4.5 cm3, and no prior radiotherapy or chemotherapy were identified as positive prognostic factors for improved PFS. On multivariate analysis, only prior radiotherapy was significant for worse PFS. CONCLUSIONS: This represents the largest study of single-session GKRS for pilocytic astrocytoma to date. Favorable long-term PFS and overall survival were observed with GKRS. Further prospective studies should be performed to evaluate appropriate radiosurgery dosing, timing, and sequencing of treatment along with their impact on toxicity and the quality of life of patients with pilocytic astrocytoma.

Email as an Encumbrance to Physician-patient Communication.

Physician-patient interaction through email poses several concerns regarding the security, efficiency, and misinterpretation of critical information. Incoming emails received by a single university-based physician in 2013 were analyzed in order to determine whether a general non-patient specific email is appropriate for patient use. Emails received were divided into seven categories: Informational, Academic, Advertisement, Organization/Department/ University, Mission Critical, Personal, and Patient. A total of 9,102 emails were received and read by the physician, with an average of 25 emails per day, out of which 823 (9%) emails were directly sent by patients. The total time spent reading emails was five days, seven hours, and 24 minutes. General email is not an effective means of streamlining physician-patient communication. Non-essential emails, which represent a majority of incoming messages, decrease the productivity of physicians and prevent them from responding to urgent messages in a timely manner. Additionally, this creates the chance for critical patient information getting lost with the volume of received emails. This could be detrimental to patient care and satisfaction. Recently, an online portal was instated to provide a method of secure communication, and less than five patient emails were received in the physician's personal email since then.

Focused Ultrasound Thalamotomy for Essential Tremor in the Setting of a Ventricular Shunt: Technical Report.

BACKGROUND: A recent randomized controlled trial of magnetic resonance imaging (MRI)-guided focused ultrasound (FUS) for essential tremor (ET) demonstrated safety and efficacy. Patients with ventricular shunts may be good candidates for FUS to minimize hardware-associated infections. OBJECTIVE: To demonstrate feasibility of FUS in this subset of patients. METHODS: A 74-yr-old male with medically refractory ET, and a right-sided ventricular shunt for normal pressure hydrocephalus, underwent FUS to the right ventro-intermedius (VIM) nucleus. The VIM nucleus was directly targeted using deterministic tractography. Clinical outcomes were measured using the Clinical Rating Scale for Tremor. RESULTS: Shunt components required 6% of the total ultrasound transducer elements to be shut off. Eight therapeutic sonications were delivered (maximum temperature, 64°), leading to a 90% improvement in hand tremor and a 100% improvement in functional disability at the 3-mo follow-up. No complications were noted. CONCLUSION: This is the first case of FUS thalamotomy in a patient with a shunt. Direct VIM targeting and achievement of therapeutic temperatures with acoustic energy is feasible in this subset of patients.

Hemorrhage risk of cerebral dural arteriovenous fistulas following Gamma Knife radiosurgery in a multicenter international consortium.

OBJECTIVE: The authors performed a study to evaluate the hemorrhagic rates of cerebral dural arteriovenous fistulas (dAVFs) and the risk factors of hemorrhage following Gamma Knife radiosurgery (GKRS). METHODS: Data from a cohort of patients undergoing GKRS for cerebral dAVFs were compiled from the International Radiosurgery Research Foundation. The annual posttreatment hemorrhage rate was calculated as the number of hemorrhages divided by the patient-years at risk. Risk factors for dAVF hemorrhage prior to GKRS and during the latency period after radiosurgery were evaluated in a multivariate analysis. RESULTS: A total of 147 patients with dAVFs were treated with GKRS. Thirty-six patients (24.5%) presented with hemorrhage. dAVFs that had any cortical venous drainage (CVD) (OR = 3.8, p = 0.003) or convexity or torcula location (OR = 3.3, p = 0.017) were more likely to present with hemorrhage in multivariate analysis. Half of the patients had prior treatment (49.7%). Post-GRKS hemorrhage occurred in 4 patients, with an overall annual risk of 0.84% during the latency period. The annual risks of post-GKRS hemorrhage for Borden type 2-3 dAVFs and Borden type 2-3 hemorrhagic dAVFs were 1.45% and 0.93%, respectively. No hemorrhage occurred after radiological confirmation of obliteration. Independent predictors of hemorrhage following GKRS included nonhemorrhagic neural deficit presentation (HR = 21.6, p = 0.027) and increasing number of past endovascular treatments (HR = 1.81, p = 0.036). CONCLUSIONS: Patients have similar rates of hemorrhage before and after radiosurgery until obliteration is achieved. dAVFs that have any CVD or are located in the convexity or torcula were more likely to present with hemorrhage. Patients presenting with nonhemorrhagic neural deficits and a history of endovascular treatments had higher risks of post-GKRS hemorrhage.

Enhanced recovery after elective spinal and peripheral nerve surgery: pilot study from a single institution.

OBJECTIVEEnhanced recovery after surgery (ERAS) protocols address pre-, peri-, and postoperative factors of a patient's surgical journey. The authors sought to assess the effects of a novel ERAS protocol on clinical outcomes for patients undergoing elective spine or peripheral nerve surgery.METHODSThe authors conducted a prospective cohort analysis comparing clinical outcomes of patients undergoing elective spine or peripheral nerve surgery after implementation of the ERAS protocol compared to a historical control cohort in a tertiary care academic medical center. Patients in the historical cohort (September-December 2016) underwent traditional surgical care. Patients in the intervention group (April-June 2017) were enrolled in a unique ERAS protocol created by the Department of Neurosurgery at the University of Pennsylvania. Primary objectives were as follows: opioid and nonopioid pain medication consumption, need for opioid use at 1 month postoperatively, and patient-reported pain scores. Secondary objectives were as follows: mobilization and ambulation status, Foley catheter use, need for straight catheterization, length of stay, need for ICU admission, discharge status, and readmission within 30 days.RESULTSA total of 201 patients underwent surgical care via an ERAS protocol and were compared to a total of 74 patients undergoing traditional perioperative care (control group). The 2 groups were similar in baseline demographics. Intravenous opioid medications postoperatively via patient-controlled analgesia was nearly eliminated in the ERAS group (0.5% vs 54.1%, p < 0.001). This change was not associated with an increase in the average or daily pain scores in the ERAS group. At 1 month following surgery, a smaller proportion of patients in the ERAS group were using opioids (38.8% vs 52.7%, p = 0.041). The ERAS group demonstrated greater mobilization on postoperative day 0 (53.4% vs 17.1%, p < 0.001) and postoperative day 1 (84.1% vs 45.7%, p < 0.001) compared to the control group. Postoperative Foley use was decreased in the ERAS group (20.4% vs 47.3%, p < 0.001) without an increase in the rate of straight catheterization (8.1% vs 11.9%, p = 0.51).CONCLUSIONSImplementation of this novel ERAS pathway safely reduces patients' postoperative opioid requirements during hospitalization and 1 month postoperatively. ERAS results in improved postoperative mobilization and ambulation.

Long-term outcomes following deep brain stimulation for Parkinson's disease.

OBJECTIVE: Deep brain stimulation (DBS) is an effective treatment for several movement disorders, including Parkinson's disease (PD). While this treatment has been available for decades, studies on long-term patient outcomes have been limited. Here, the authors examined survival and long-term outcomes of PD patients treated with DBS. METHODS: The authors conducted a retrospective analysis using medical records of their patients to identify the first 400 consecutive patients who underwent DBS implantation at their institution from 1999 to 2007. The medical record was used to obtain baseline demographics and neurological status. The authors performed survival analyses using Kaplan-Meier estimation and multivariate regression using Cox proportional hazards modeling. Telephone surveys were used to determine long-term outcomes. RESULTS: Demographics for the cohort of patients with PD (n = 320) were as follows: mean age of 61 years, 70% male, 27% of patients had at least 1 medical comorbidity (coronary artery disease, congestive heart failure, diabetes mellitus, atrial fibrillation, or deep vein thrombosis). Kaplan-Meier survival analysis on a subset of patients with at least 10 years of follow-up (n = 200) revealed a survival probability of 51% (mean age at death 73 years). Using multivariate regression, the authors found that age at implantation (HR 1.02, p = 0.01) and male sex (HR 1.42, p = 0.02) were predictive of reduced survival. Number of medical comorbidities was not significantly associated with survival (p > 0.5). Telephone surveys were completed by 40 surviving patients (mean age 55.1 ± 6.4 years, 72.5% male, 95% subthalamic nucleus DBS, mean follow-up 13.0 ± 1.7 years). Tremor responded best to DBS (72.5% of patients improved), while other motor symptoms remained stable. Ability to conduct activities of daily living (ADLs) remained stable (dressing, 78% of patients; running errands, 52.5% of patients) or worsened (preparing meals, 50% of patients). Patient satisfaction, however, remained high (92.5% happy with DBS, 95% would recommend DBS, and 75% felt it provided symptom control). CONCLUSIONS: DBS for PD is associated with a 10-year survival rate of 51%. Survey data suggest that while DBS does not halt disease progression in PD, it provides durable symptomatic relief and allows many individuals to maintain ADLs over long-term follow-up greater than 10 years. Furthermore, patient satisfaction with DBS remains high at long-term follow-up.

Patterns of opioid use in patients with trigeminal neuralgia undergoing neurosurgery.

OBJECTIVE: First-line treatment for trigeminal neuralgia (TN) is pharmacological management using antiepileptic drugs (AEDs), e.g., carbamazepine (CBZ) and oxcarbazepine (OCBZ). Surgical intervention has been shown to be an effective and durable treatment for TN that is refractory to medical therapy. Despite the lack of evidence for efficacy in patients with TN, the authors hypothesized that patients with neuropathic facial pain are prescribed opioids at high rates, and that neurosurgical intervention may lead to a reduction in opioid use. METHODS: This is a retrospective study of patients with facial pain seen by a single neurosurgeon. All patients completed a survey on pain medications, medical comorbidities, prior interventions for facial pain, and a validated pain outcome tool (the Penn Facial Pain Scale). Patients subsequently undergoing neurosurgical intervention completed a survey at the 1-month follow-up in the office, in addition to telephone interviews using a standardized script between 1 and 6 years after intervention. Univariate and multivariate logistic regression were used to predict opioid use. RESULTS: The study cohort consisted of 309 patients (70% Burchiel type 1 TN [TN1], 18% Burchiel type 2 [TN2], 6% atypical facial pain [AFP], and 6% TN secondary to multiple sclerosis [TN-MS]). At initial presentation, 20% of patients were taking opioids. Of these patients, 55% were receiving concurrent opioid therapy with CBZ/OCBZ, and 84% were receiving concurrent therapy with at least one type of AED. Facial pain diagnosis (for diagnoses other than TN1, odds ratio [OR] 2.5, p = 0.01) and facial pain intensity at its worst (for each unit increase, OR 1.4, p = 0.005) were predictors of opioid use at baseline. Neurosurgical intervention led to a reduction in opioid use to 8% at long-term follow-up (p < 0.01, Fisher's exact test; n = 154). Diagnosis (for diagnoses other than TN1, OR 4.7, p = 0.002) and postintervention reduction in pain at its worst (for each unit reduction, OR 0.8, p < 10-3) were predictors of opioid use at long-term follow-up. On subgroup analysis, patients with TN1 demonstrated a decrease in opioid use to 5% at long-term follow-up (p < 0.05, Fisher's exact test), whereas patients with non-TN1 facial pain did not. In the nonsurgical group, there was no statistically significant decrease in opioid use at long-term follow-up (n = 81). CONCLUSIONS: In spite of its high potential for abuse, opioid use, mostly as an adjunct to AEDs, is prevalent in patients with facial pain. Opportunities to curb opioid use in TN1 include earlier neurosurgical intervention.

Predictors of Neurological Outcome Following Subaxial Cervical Spine Trauma.

Background The treatment of traumatic subaxial cervical spine injuries remains controversial. The American Spinal Injury Association (ASIA) impairment scale (AIS) is a widely-used metric to score neurological function after spinal cord injury (SCI). Here, we evaluated the outcomes of patients who underwent treatment of subaxial cervical spine injuries to identify predictors of neurologic function after injury and treatment. Methods We performed a retrospective logistic regression analysis to determine predictors of neurological outcome; 76 patients met the inclusion criteria and presented for a three-month follow-up. The mean age was 50.6±18.7 years old and the majority of patients were male (n=49, 64%). Results The majority of patients had stable AIS scores at three months (n=56, 74%). A subset of patients showed improvement at three months (n=16, 21%), while a small subset of patients had neurological decline at three months (n=4, 5%). In our model, increasing patient age (odds ratio [OR] 1.39, 1.10-2.61 95% confidence interval [CI], P<0.001) and a previous or current diagnosis of cancer (OR 22.4, 1.25-820 95% CI, P=0.04) significantly increased the odds of neurological decline at three months. In patients treated surgically, we found that delay in surgical treatment (>24 hours) was associated with a decreased odds of neurological improvement (OR 0.24, 0.05-0.99 95% CI, P=0.048). Cervical spine injuries are heterogeneous and difficult to manage. Conclusion We found that increasing patient age and an oncologic history were associated with neurological deterioration while a delay in surgical treatment was associated with decreased odds of improvement. These predictors of outcome may be used to guide prognosis and treatment decisions.

Predictors of Failure of Nonoperative Management Following Subaxial Spine Trauma and Creation of Modified Subaxial Injury Classification System.

BACKGROUND: Subaxial cervical spine injuries may be treated with either nonoperative stabilization or surgical fixation. The subaxial injury classification (SLIC) provides 1 method for suggesting the degree of necessity for surgery. In the current study, we examined if the SLIC score, or other preoperative metrics, can predict failure of nonoperative management. METHODS: We performed a retrospective chart review to identify patients who presented with acute, nonpenetrating, subaxial cervical spine injury within our health system between 2007 and 2016. Patient demographics, medical comorbidities, injuries, and treatments were collected. Logistic regression analysis was used to determine potential predictors of failure of nonoperative management. RESULTS: During the study period, 40 patients met the inclusion criteria. A small subset of patients failed nonoperative management (n = 5, 12.5%). The mean SLIC score was 3.9 ± 1.9; however, 14 (35%) patients had scores >4. Neither total SLIC score (P = 0.68) nor SLIC subscores (morphology [P = 0.96], discoligamentous complex [P = 0.83], neurologic status [P = 0.60]) predicted failure of nonoperative treatment. Time to evaluation/treatment did predict failure of nonoperative management. Evaluation within 8 hours of injury was a negative predictor of failure (odds ratio = 0.03, P = 0.001) and evaluation 24 hours or more after injury was a positive predictor of failure (odds ratio = 66.00, P < 0.001). We created a modified SLIC score on the basis of these findings, which significantly predicted failure of nonoperative management (P = 0.044). CONCLUSIONS: Management of subaxial spine injuries is complex. In our cohort, SLIC scoring did not adequately predict odds of failure of nonoperative management. Time to evaluation, however, did. We created a modified SLIC score that significantly predicted failure of nonoperative management.

Fully endoscopic microvascular decompression for hemifacial spasm.

OBJECTIVE: Hemifacial spasm (HFS) is characterized by involuntary tonic and/or clonic contractions of facial nerve muscles. Fully endoscopic microvascular decompression (E-MVD) for HFS has not been widely adopted. This paper aims to illustrate the safety and efficacy of the fully endoscopic technique for HFS treatment. METHODS: The authors conducted a single-center retrospective study of 27 patients (28 separate E-MVD cases; 1 patient had bilateral E-MVD) diagnosed with HFS who underwent fully E-MVD from January 2013 to October 2016. Intraoperative brainstem auditory evoked potentials and lateral spread resolution were reviewed. Outcome was based on the clinical status of the patient at the last contact point with the senior author. Complications were categorized as facial weakness, hearing loss, ataxia, dysphagia, or any adverse event able to be attributed to the surgical procedure. RESULTS: HFS was relieved either completely or partially in the majority of cases (24 of 28, 85.7%). Of the 28 separate procedures, 17 (60.7%) resulted in complete resolution of symptoms, 4 (14.3%) resulted in near-complete resolution, 2 (7.1%) resulted in 50% reduction of symptoms, 1 (3.6%) resulted in minimal reduction, and 4 (14.3%) resulted in no relief. Of the 27 patients, 26 (96%) had no permanent postoperative complications. In multivariate logistic regression, the best predictor of greater than 50% resolution of spasm was resolution of intraoperative lateral spread response. CONCLUSIONS: A fully E-MVD for HFS provides a safe and comprehensive view of the neurovascular conflict. Exclusive use of the endoscope in MVD is both safe and feasible in the treatment of HFS. Attention to lateral spread response monitoring remains an integral part of comprehensive neurosurgical management.

Reduced long-term cost and increased patient satisfaction with rechargeable implantable pulse generators for deep brain stimulation.

OBJECTIVE: Deep brain stimulation (DBS) has revolutionized the treatment of neurological disease, but its therapeutic efficacy is limited by the lifetime of the implantable pulse generator (IPG) batteries. At the end of the battery life, IPG replacement surgery is required. New IPGs with rechargeable batteries (RC-IPGs) have recently been introduced and allow for decreased reoperation rates for IPG replacements. The authors aimed to examine the merits and limitations of these devices. METHODS: The authors reviewed the medical records of patients who underwent DBS implantation at their institution. RC-IPGs were placed either during initial DBS implantation or during an IPG change. A cost analysis was performed that compared RC-IPGs with standard IPGs, and telephone patient surveys were conducted to assess patient satisfaction. RESULTS: The authors identified 206 consecutive patients from 2011 to 2016 who underwent RC-IPG placement (mean age 61 years; 67 women, 33%). Parkinson's disease was the most common indication for DBS (n = 144, 70%), followed by essential tremor (n = 41, 20%), dystonia (n = 13, 6%), depression (n = 5, 2%), multiple sclerosis tremor (n = 2, 1%), and epilepsy (n = 1, 0.5%). DBS leads were typically placed bilaterally (n = 192, 93%) and targeted the subthalamic nucleus (n = 136, 66%), ventral intermediate nucleus of the thalamus (n = 43, 21%), internal globus pallidus (n = 21, 10%), ventral striatum (n = 5, 2%), or anterior nucleus of the thalamus (n = 1, 0.5%). RC-IPGs were inserted at initial DBS implantation in 123 patients (60%), while 83 patients (40%) were converted to RC-IPGs during an IPG replacement surgery. The authors found that RC-IPG implantation resulted in $60,900 of cost savings over the course of 9 years. Furthermore, patient satisfaction was high with RC-IPG implantation. Overall, 87.3% of patients who responded to the survey were satisfied with their device, and only 6.7% found the rechargeable component difficult to use. In patients who were switched from a standard IPG to RC-IPG, the majority who responded (70.3%) preferred the rechargeable IPG. CONCLUSIONS: RC-IPGs can provide DBS patients with long-term therapeutic benefit while minimizing the need for battery replacement surgery. The authors have implanted rechargeable stimulators in 206 patients undergoing DBS surgery, and here they demonstrate the cost-effectiveness and high patient satisfaction associated with this procedure.

A Prospective Detailed Time Analysis Study of 18 Patients Undergoing Elective Single-Level Open Lumbar Microdiscectomy Spinal Surgery Compared with Centers for Medicare and Medicaid Services Reimbursement Guidelines.

BACKGROUND: Single-level open lumbar microdiscectomy surgery is one of the most straightforward and effective spinal surgeries performed by spinal surgeons today to treat disk herniation. Although a common operation, little in the literature is reported on the exact overall time, cost, and effort associated with the performance of this surgery. The consistency of this operation across institutions and disciplines makes it a good starting point to accurately track the total time and effort of all phases of the surgical intervention. METHODS: Eighteen patients undergoing elective single-level open lumbar microdiscectomy surgery were prospectively enrolled in this study. The time spent interacting with each patient by every member of the surgical team was tracked and recorded along will every phone call and e-mail. All perioperative times associated with the surgery were tracked and analyzed. Each patient was followed from their first interaction through surgery and for the first 3 months postoperatively. RESULTS: The advanced practice providers spent the most time with the patient both pre- and postoperatively followed by the surgeon and resident. A total of 2.98 hours was spent with the patient preoperatively in clinic and 1.69 hours postoperatively. The total time commitment of an institution treating this condition was 12.56 hours. CONCLUSIONS: Comparing our results with the Centers for Medicare and Medicaid Services data, a significant discrepancy and underestimation was observed. As such, we hope our results enable health care providers to more accurately allocate resources for the provision of high-quality medical care to patients with this increasingly common condition.

Upfront Gamma Knife radiosurgery for Cushing's disease and acromegaly: a multicenter, international study.

OBJECTIVE: Gamma Knife radiosurgery (GKS) is typically used after failed resection in patients with Cushing's disease (CD) and acromegaly. Little is known about the upfront role of GKS for patients with CD and acromegaly. In this study, the authors examine the outcome of upfront GKS for patients with these functioning adenomas. METHODS: An international group of 7 Gamma Knife centers sent pooled data from 46 patients (21 with CD and 25 with acromegaly) undergoing upfront GKS to the coordinating center of the study for analysis. Diagnosis was established on the basis of clinical, endocrine, and radiological studies. All patients were treated on a common radiosurgical platform and longitudinally followed for tumor control, endocrine remission, and hypopituitarism. Patients received a tumor median margin dose of 25 Gy (range 12-40.0 Gy) at a median isodose of 50%. RESULTS: The median endocrine follow-up was 69.5 months (range 9-246 months). Endocrine remission was achieved in 51% of the entire cohort, with 28% remission in acromegaly and 81% remission for those with CD at the 5-year interval. Patients with CD achieved remission earlier as compared to those with acromegaly (p = 0.0005). In patients post-GKS, the pituitary adenoma remained stable (39%) or reduced (61%) in size. Hypopituitarism occurred in 9 patients (19.6%), and 1 (2.2%) developed third cranial nerve (CN III) palsy. Eight patients needed further intervention, including repeat GKS in 6 and transsphenoidal surgery in 2. CONCLUSIONS: Upfront GKS resulted in good tumor control as well as a low rate of adverse radiation effects in the whole group. Patients with CD achieved a faster and far better remission rate after upfront GKS in comparison to patients with acromegaly. GKS can be considered as an upfront treatment in carefully selected patients with CD who are unwilling or unable to undergo resection, but it has a more limited role in acromegaly.

Growth of a Sacral Perineural (Tarlov) Cyst: Clinical Images.

Although Tarlov cysts (TC) were first described in 1938, our understanding of these common spinal lesions remains poor. As TCs represent incidental findings in the vast majority of cases, evidence to guide their management is limited to small case series. When they are symptomatic, the presentation can have significant overlap with degenerative spine disease. This is the first report demonstrating growth of TCs. The patient underwent open surgical reduction of the symptomatic TCs, leading to improvement in her symptoms.

Technique of Whole-Sellar Stereotactic Radiosurgery for Cushing Disease: Results from a Multicenter, International Cohort Study.

BACKGROUND: Stereotactic radiosurgery (SRS) is used to manage patients with Cushing disease (CD) who have failed surgical/medical management. Because many patients with recurrent/persistent CD lack an identifiable adenoma on neuroimaging, whole-sellar SRS has been increasingly used. Thus, we sought to define the outcomes of patients undergoing whole-sellar SRS. METHODS: An international, multicenter, retrospective cohort design was used to define clinical/endocrine outcomes for patients undergoing whole-sellar SRS for CD. Propensity-score matching was used to compare patients undergoing whole-sellar SRS and patients who underwent discreet adenoma-targeted SRS. RESULTS: A total of 68 patients underwent whole-sellar SRS, with a mean endocrine follow-up of 5.3 years. The mean treatment volume was 2.6 cm3, and the mean margin dose was 22.4 Gy. The 5-year actuarial remission rate was 75.9%, and the median time to remission was 12-months. Treatment volumes >1.6 cm3 were associated with shorter times to remission (P < 0.05). The 5-year recurrence-free survival rate was 86.0%. Decreased margin and maximum treatment doses were associated with recurrence (P < 0.05). New pituitary hormone deficiency occurred in 15 patients (22.7%). An additional 210 patients were identified who underwent adenoma-targeted SRS. There was no difference in remission rate, time to remission, recurrence-free survival or new endocrinopathy development between patients who underwent whole-sellar SRS and those who underwent discreet adenoma-targeted SRS. CONCLUSIONS: Whole-sellar GKRS is effective in controlling CD when an adenoma is not clearly defined on imaging or when an invasive adenoma is suspected at the time of initial surgery. Patients who undergo whole-sellar SRS have outcomes and rates of new pituitary hormone deficiency similar to those of patients who undergo discrete adenoma-targeted GKRS.

Neurologic Status on Presentation as Predictive Measurement in Success of Closed Reduction in Traumatic Cervical Facet Fractures.

BACKGROUND: Dislocations to cervical facets resulting from traumatic injury often lead to neurologic impairment and can be treated both surgically and in a closed manner. OBJECTIVE: We sought to evaluate the utilization of closed reduction in the initial management of bilateral facet dislocations over the past 10 years at our institution. METHODS: We retrospectively reviewed the charts of patients who experienced subaxial cervical facet injury within the Penn Health System between 1 June 2006 and 1 June 2016 to identify patients with bilateral jumped/perched facets. The neurologic injury was identified on the basis of the American Spinal Injury Association (ASIA) spinal cord injury score. Analysis of variance and 2-sample t-tests were used to compare continuous distributions, and chi-square tests were used to compare categorical distributions. RESULTS: We focused our analyses on patients who presented with bilateral jumped/perched facets with (ASIA A and B) or without (ASIA C, D, E) complete voluntary motor deficit and underwent attempted closed reduction. We found that the rate of successful closed reduction was significantly higher in incomplete motor deficits (5/5, P = 0.04, chi-square test) as compared with complete motor deficits (n = 2/11). CONCLUSION: Our results demonstrate a significant difference in the success rate of closed reduction in patients with good neurologic status on presentation (ASIA A or B), compared with those with poor neurologic status (ASIA C, D, and E). These results suggest that closed reduction should be attempted in patients with good motor examinations on presentation, whereas those with significant deficits may benefit from earlier surgical intervention.