Search Results

You are looking at 1 - 10 of 39 items for

  • Author or Editor: William S. Anderson x
  • Refine by Access: all x
Clear All Modify Search
Full access

William S. Anderson, Eric H. Kossoff, Gregory K. Bergey, and George I. Jallo

Object

The authors summarize one center's experience with a novel device, the Responsive Neurostimulation (RNS) system, which is used to treat seizures, and they provide technical details regarding the implantation procedure.

Methods

The authors reviewed seizure detection, cortical stimulation, and clinical data obtained in 7 patients in whom the RNS system was implanted. Data pertaining to seizure alteration are provided for the first 4 implant-treated patients. The implantation procedure in the case of one patient with occipital lobe heterotopia is included.

Results

Based on patients' seizure diaries, the implanted devices functioned at a high sensitivity for clinical seizure detection. Reductions in seizure frequency, based on their diaries and on clinic follow-up notes, ranged from 50 to 75%. No adverse stimulation-induced side effects were noted, and no hardware malfunctions requiring explantation occurred. Generator replacements for battery depletion were required at 11, 17, and 20 months in 3 patients. The implantation procedure was well tolerated, and postoperative hospital stays were short. A revision cranioplasty for a skull defect was performed in the index patient, whose case will be discussed in the most detail.

Conclusions

The results obtained in this small preliminary series demonstrate a safe implantation method for the responsive neurostimulation device.

Full access

Smruti K. Patel, Qasim Husain, Jean Anderson Eloy, William T. Couldwell, and James K. Liu

Developed over a century ago, the transsphenoidal approach to access lesions of the pituitary gland and sella turcica has transformed the field of neurosurgery, largely due to the work of Oskar Hirsch and Harvey Cushing. Furthermore, its use and modification in the early 1900s was perhaps one of Cushing's greatest legacies to skull base surgery. However, Cushing, who had worked relentlessly to improve the transsphenoidal route to the pituitary region, abandoned the approach by 1929 in his pursuit to master transcranial approaches to the suprasellar region. Hirsch and a few other surgeons continued to perform transsphenoidal operations, but they were unable to maintain the popularity of the approach among their peers.

During a time when transsphenoidal surgery was on the brink of extinction, a critical lineage of 3 key surgeons—Norman Dott, Gerard Guiot, and Jules Hardy—would resurrect the art, each working to further improve the procedure. Dott, Cushing's apprentice from 1923 to 1924, brought his experiences with transsphenoidal surgery to Edinburgh, Scotland, and along the way, developed the lighted nasal speculum to provide better illumination in the narrow working area. Guiot, inspired by Dott, adopted his technique and used intraoperative radiofluoroscopic technique for image guidance. Hardy, a fellow of Guiot, from Montreal, Canada, revolutionized transsphenoidal microsurgery with the introduction of the binocular microscope and selective adenomectomy.

The teachings of these pioneers have endured over time and are now widely used by neurosurgeons worldwide. In this paper, we review the lineage and contributions of Dott, Guiot, and Hardy who served as crucial players in the preservation of transsphenoidal surgery.

Restricted access

William S. Anderson, Herman Christopher Lawson, Allan J. Belzberg, and Frederick A. Lenz

Object

The purpose of this cadaveric study was to explore a modification to the Bertrand procedure for the treatment of spasmodic torticollis, namely the denervation of the levator scapulae (LS) muscle for laterocollis.

Methods

The authors performed a series of 9 cadaveric dissections. Five were done to identify the anterior innervation of the LS, and the remaining 4 were to identify the tendinous insertions of the LS onto the lateral masses of the cervical spine via a posterior approach. The nerve supply to the LS from the anterior divisions of the C-3 and C-4 nerve roots and the contribution from the dorsal scapular nerve were identified over the anterior surface of the muscle.

Results

The C-3 and C-4 nerve root branches were situated within 2 cm of each other and inferior to the punctum nervosum. The dorsal scapular contribution was clearly identified in 2 cadavers. Selective denervation of this muscle is possible through the same posterior triangle incision used for denervating the sternocleidomastoid muscle of its accessory nerve branches. This approach will be helpful in patients with laterocollis contralateral to the direction of chin turning. The authors compare this approach to the posterior approach for sectioning the insertions of the LS muscle onto the C1–4 posterior tubercles. The latter approach is appropriate for ipsilateral laterocollis.

Conclusions

The posterior triangle approach for denervating the LS muscle is a safe and easy addition to the Bertrand procedure and can be helpful in selected cases of torticollis with a laterocollis component.

Restricted access

Scott L. Parker, Stephen K. Mendenhall, David N. Shau, Owoicho Adogwa, William N. Anderson, Clinton J. Devin, and Matthew J. McGirt

Object

Spine surgery outcome studies rely on patient-reported outcome (PRO) measurements to assess treatment effect, but the extent of improvement in the numerical scores of these questionnaires lacks a direct clinical meaning. Because of this, the concept of a minimum clinically important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. As utilization of spinal fusion has increased over the past decade, so has the incidence of same-level recurrent stenosis following index lumbar fusion, which commonly requires revision decompression and fusion. The MCID remains uninvestigated for any PROs in the setting of revision lumbar surgery for this pathology.

Methods

In 53 consecutive patients undergoing revision surgery for same-level recurrent lumbar stenosis–associated back and leg pain, PRO measures of back and leg pain were assessed preoperatively and 2 years postoperatively, using the visual analog scale for back pain (VAS-BP) and leg pain (VAS-LP), Oswestry Disability Index (ODI), Physical and Mental Component Summary categories of the 12-Item Short Form Health Survey (SF-12 PCS and MCS) for quality of life, Zung Depression Scale (ZDS), and EuroQol-5D health survey (EQ-5D). Four established anchor-based MCID calculation methods were used to calculate MCID (average change; minimum detectable change; change difference; and receiver operating characteristic curve analysis) for 2 separate anchors (health transition index of the SF-36 and the satisfaction index).

Results

All patients were available for 2-year PRO assessment. Two years after surgery, a significant improvement was observed for all PROs assessed. The 4 MCID calculation methods generated a range of MCID values for each of the PROs (VAS-BP 2.2–6.0, VAS-LP 3.9–7.5, ODI 8.2–19.9, SF-12 PCS 2.5–12.1, SF-12 MCS 7.0–15.9, ZDS 3.0–18.6, and EQ-5D 0.29–0.52). Each patient answered synchronously for the 2 anchors, suggesting both of these anchors are equally appropriate and valid for this patient population.

Conclusions

The same-level recurrent stenosis surgery-specific MCID is highly variable based on calculation technique. The “minimum detectable change” approach is the most appropriate method for calculation of MCIDs in this population because it was the only method to reliably provide a threshold above the 95% confidence interval of the unimproved cohort (greater than the measurement error). Based on this method, the MCID thresholds following neural decompression and fusion for symptomatic same-level recurrent stenosis are 2.2 points for VAS-BP, 5.0 points for VAS-LP, 8.2 points for ODI, 2.5 points for SF-12 PCS, 10.1 points for SF-12 MCS, 4.9 points for ZDS, and 0.39 QALYs for EQ-5D.

Restricted access

Min Jae Kim, Brian Y. Hwang, David Mampre, Serban Negoita, Yohannes Tsehay, Haris I. Sair, Joon Y. Kang, and William S. Anderson

OBJECTIVE

Piriform cortex (PC) is one of the critical structures in the epileptogenesis of mesial temporal lobe epilepsy (mTLE), but its role is poorly understood. The authors examined the utility of apparent diffusion coefficient (ADC; an MR-based marker of tissue pathology) of the PC as a predictor of seizure outcome in patients with mTLE undergoing MR-guided laser interstitial thermal therapy (MRgLITT).

METHODS

A total of 33 patients diagnosed with mTLE who underwent MRgLITT at the authors’ institution were included in the study. The 6-month postoperative seizure outcomes were classified using the International League Against Epilepsy (ILAE) system as good (complete seizure freedom, ILAE class I) and poor (seizure present, ILAE classes II–VI). The PC and ablation volumes were manually segmented from both the preoperative and intraoperative MRI sequences, respectively. The mean ADC intensities of 1) preablation PC; 2) total ablation volume; 3) ablated portion of PC; and 4) postablation residual PC were calculated and compared between good and poor outcome groups. Additionally, the preoperative PC volumes and proportion of PC volume ablated were examined and compared between the subjects in the two outcome groups.

RESULTS

The mean age at surgery was 36.5 ± 3.0 years, and the mean follow-up duration was 1.9 ± 0.2 years. Thirteen patients (39.4%) had a good outcome. The proportion of PC ablated was significantly associated with seizure outcome (10.16 vs 3.30, p < 0.05). After accounting for the variability in diffusion tensor imaging acquisition parameters, patients with good outcome had a significantly higher mean ADC of the preablation PC (0.3770 vs −0.0108, p < 0.05) and the postoperative residual PC (0.4197 vs 0.0309, p < 0.05) regions compared to those with poor outcomes. No significant differences in ADC of the ablated portion of PC were observed (0.2758 vs −0.4628, p = 0.12) after performing multivariate analysis.

CONCLUSIONS

A higher proportion of PC ablated was associated with complete seizure freedom. Preoperative and postoperative residual ADC measures of PC were significantly higher in the good seizure outcome group in patients with mTLE who underwent MRgLITT, suggesting that ADC analysis can assist with postablation outcome prediction and patient stratification.

Free access

William S. Bolton, Parjeet Kaur Gharial, Christopher Akhunbay-Fudge, Paul Chumas, Ryan K. Mathew, and Ian A. Anderson

OBJECTIVE

Recent evidence has suggested that an admission neutrophil-to-lymphocyte ratio (NLR) of ≥ 5.9 predicts delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH). The primary aims of this study were to assess reproducibility and to ascertain the predictive ability of NLR on subsequent days postictus. Secondary aims included identification of additional inflammatory markers.

METHODS

A single-center, retrospective study of all patients aged ≥ 18 years with aSAH between May 2014 and July 2018 was performed. Patient characteristics, DCI incidence, operative features, and outcomes (on discharge and at 3 months postictus) were recorded. C-reactive protein (CRP) and full blood count differentials were recorded on admission and through day 8 postictus or at discharge. In total, 403 patients were included in the final analysis.

RESULTS

Ninety-six patients (23.8%) developed DCI with a median time from ictus of 6 days (IQR 3.25–8 days). A platelet-to-lymphocyte ratio (PLR) cutoff ≥ 157 and CRP cutoff ≥ 27 was used in our cohort. In a multiple binary logistic regression model, after controlling for known DCI predictors, day 2 NLR ≥ 5.9 (OR 2.194, 95% CI 1.099–4.372; p = 0.026), day 1 PLR ≥ 157 (OR 2.398, 95% CI 1.1072–5.361; p = 0.033), day 2 PLR ≥ 157 (OR 2.676, 95% CI 1.344–5.329; p = 0.005), and CRP ≥ 27 on days 3, 4, and 5 were predictive of DCI.

CONCLUSIONS

The results of this study have confirmed the association between NLR and DCI and have demonstrated the predictive potential of PLR and CRP, suggesting that NLR and PLR at day 2, and CRP from day 3 onward, may be better predictors of DCI than those measurements at the time of ictus.

Full access

Richard F. Schmidt, Osamah J. Choudhry, Ramya Takkellapati, Jean Anderson Eloy, William T. Couldwell, and James K. Liu

A little over a century ago, in 1907, at the University of Innsbruck, Hermann Schloffer performed the first transsphenoidal surgery on a living patient harboring a pituitary adenoma. Schloffer used a superior nasal route via a transfacial lateral rhinotomy incision. This was perhaps his greatest academic contribution to neurosurgery. Despite the technological limitations of that time, Schloffer's operation was groundbreaking in that it laid the foundation for future development and refinement of transsphenoidal pituitary surgery, influencing prominent surgeons such as Oskar Hirsch and Harvey Cushing. Even after undergoing multiple modifications and a brief fall into obscurity, the transsphenoidal approach has endured through generations of surgeons and remains the preferred approach for lesions of the sella turcica to this day. Although Schloffer performed primarily abdominal surgery in his practice, his contributions to the transsphenoidal approach have had a lasting impact in the field of pituitary and skull base surgery. The authors review the life and career of Hermann Schloffer, the surgical details of his transsphenoidal operation, and the legacy that it has left on the field of pituitary surgery.

Restricted access

Scott L. Parker, Stephen K. Mendenhall, David Shau, Owoicho Adogwa, Joseph S. Cheng, William N. Anderson, Clinton J. Devin, and Matthew J. McGirt

Object

Spinal surgical outcome studies rely on patient-reported outcome (PRO) measurements to assess treatment effect. A shortcoming of these questionnaires is that the extent of improvement in their numerical scores lack a direct clinical meaning. As a result, the concept of minimum clinical important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. As utilization of spinal fusion has increased over the past decade, so has the incidence of adjacent-segment degeneration following index lumbar fusion, which commonly requires revision laminectomy and extension of fusion. The MCID remains uninvestigated for any PROs in the setting of revision lumbar surgery for adjacent-segment disease (ASD).

Methods

In 50 consecutive patients undergoing revision surgery for ASD-associated back and leg pain, PRO measures of back and leg pain on a visual analog scale (BP-VAS and LP-VAS, respectively), Oswestry Disability Index (ODI), 12-Item Short Form Health Survey Physical and Mental Component Summaries (SF-12 PCS and MCS, respectively), and EuroQol-5D health survey (EQ-5D) were assessed preoperatively and 2 years postoperatively. The following 4 well-established anchor-based MCID calculation methods were used to calculate MCID: average change; minimum detectable change (MDC); change difference; and receiver operating characteristic curve (ROC) analysis for the following 2 separate anchors: health transition item (HTI) of the SF-36 and satisfaction index.

Results

All patients were available for 2-year PRO assessment. Two years after surgery, a statistically significant improvement was observed for all PROs (mean changes: BP-VAS score [4.80 ± 3.25], LP-VAS score [3.28 ± 3.25], ODI [10.24 ± 13.49], SF-12 PCS [8.69 ± 12.55] and MCS [8.49 ± 11.45] scores, and EQ-5D [0.38 ± 0.45]; all p < 0.001). The 4 MCID calculation methods generated a range of MCID values for each of the PROs (BP-VAS score, 2.3–6.5; LP-VAS score, 1.7–4.3; ODI, 6.8–16.9; SF-12 PCS, 6.1–12.6; SF-12 MCS, 2.4–10.8; and EQ-5D, 0.27–0.54). The area under the ROC curve was consistently greater for the HTI anchor than the satisfaction anchor, suggesting this as a more accurate anchor for MCID.

Conclusions

Adjacent-segment disease revision surgery–specific MCID is highly variable based on calculation technique. The MDC approach with HTI anchor appears to be most appropriate for calculation of MCID after revision lumbar fusion for ASD because it provided a threshold above the 95% CI of the unimproved cohort (greater than the measurement error), was closest to the mean change score reported by improved and satisfied patients, and was not significantly affected by choice of anchor. Based on this method, MCID following ASD revision lumbar surgery is 3.8 points for BP-VAS score, 2.4 points for LP-VAS score, 6.8 points for ODI, 8.8 points for SF-12 PCS, 9.3 points for SF-12 MCS, and 0.35 quality-adjusted life-years for EQ-5D.

Restricted access

Scott L. Parker, Owoicho Adogwa, Alexandra R. Paul, William N. Anderson, Oran Aaronson, Joseph S. Cheng, and Matthew J. McGirt

Object

Outcome studies for spine surgery rely on patient-reported outcomes (PROs) to assess treatment effects. Commonly used health-related quality-of-life questionnaires include the following scales: back pain and leg pain visual analog scale (BP-VAS and LP-VAS); the Oswestry Disability Index (ODI); and the EuroQol-5D health survey (EQ-5D). A shortcoming of these questionnaires is that their numerical scores lack a direct meaning or clinical significance. Because of this, the concept of the minimum clinically important difference (MCID) has been put forth as a measure for the critical threshold needed to achieve treatment effectiveness. By this measure, treatment effects reaching the MCID threshold value imply clinical significance and justification for implementation into clinical practice.

Methods

In 45 consecutive patients undergoing transforaminal lumbar interbody fusion (TLIF) for low-grade degenerative lumbar spondylolisthesis-associated back and leg pain, PRO questionnaires measuring BP-VAS, LPVAS, ODI, and EQ-5D were administered preoperatively and at 2 years postoperatively, and 2-year change scores were calculated. Four established anchor-based MCID calculation methods were used to calculate MCID, as follows: 1) average change; 2) minimum detectable change (MDC); 3) change difference; and 4) receiver operating characteristic curve analysis for two separate anchors (the health transition index [HTI] of the 36-Item Short Form Health Survey [SF-36], and the satisfaction index).

Results

All patients were available at the 2-year follow-up. The 2-year improvements in BP-VAS, LP-VAS, ODI, and EQ-5D scores were 4.3 ± 2.9, 3.8 ± 3.4, 19.5 ± 11.3, and 0.43 ± 0.44, respectively (mean ± SD). The 4 MCID calculation methods generated a range of MCID values for each of the PROs (BP-VAS, 2.1–5.3; LP-VAS, 2.1–4.7; ODI, 11–22.9; and EQ-5D, 0.15–0.54). The mean area under the curve (AUC) for the receiver operating characteristic curve from the 4 PRO-specific calculations was greater for the HTI versus satisfaction anchor (HTI [AUC 0.73] vs satisfaction [AUC 0.69]), suggesting HTI as a more accurate anchor.

Conclusions

The TLIF-specific MCID is highly variable based on calculation technique. The MDC approach with the SF-36 HTI anchor appears to be most appropriate for calculating MCID because it provided a threshold above the 95% CI of the unimproved cohort (greater than the measurement error), was closest to the mean change score reported by improved and satisfied patients, and was least affected by the choice of anchor. Based on the MDC method with HTI anchor, MCID scores following TLIF are 2.1 points for BP-VAS, 2.8 points for LP-VAS, 14.9 points for ODI, and 0.46 quality-adjusted life years for EQ-5D.