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Brown, Nolan J.

https://orcid.org/0000-0002-6025-346X

Mayo Clinic

University of California San Diego

Citations 55

Surgical Treatment of Skull Base Chordomas Extending to the Atlantoaxial Spine in the Pediatric Population
Liu, Matthew , Loya, Joshua , Sahyouni, Ronald , Brown, Nolan J. , Gendreau, Julian , Lee, James , Abraham, Mickey Ellis , Gonda, David D. , Levy, Michael L.

Journal of Neurological Surgery Part B: Skull Base | March 4, 2022 | Volume: 83 | Issue: S 01 | Pages: S1-S270

10.1055/s-0042-1743631 Get It

Spinal pathologies and management strategies associated with cervical angina (pseudoangina): a systematic review
Brown, Nolan J. , Ransom, Seth C. , Sahyouni, Ronald , Ransom, Ryan Chase, Shahrestani, Shane , Lien, Brian V. , Tafreshi, Ali R., Ransom, Ryan C.

Journal of Neurosurgery: Spine | December 4, 2020 | Volume: 34 | Issue: 3 | Pages: 506-513

10.3171/2020.7.spine20866 Get It

OBJECTIVECervical angina, or pseudoangina pectoris, is a noncardiac syndrome of chest pain that often mimics angina pectoris but is a disease of the spine. Diagnosis of cervical angina can be difficult and is often overlooked, although once identified, it can be successfully managed through conservative therapies and/or a variety of surgical interventions. Ultimately, cervical angina is an important component of the list of differential diagnoses in noncardiac chest pain. In the present study, the authors report the first comprehensive systematic review of the range of cervical and thoracic pathologies associated with cervical angina, as well as the different treatment methods used to manage this condition.METHODSA systematic review was performed according to PRISMA guidelines and using PubMed, Web of Science, and Cochrane databases from database inception to April 29, 2020, to identify studies describing spinal pathologies related to cervical angina. The following Boolean search was performed: (“cervical” OR “thoracic”) AND (“angina” OR “chest pain”) AND (“herniation” OR “OPLL”). Variables extracted included patient demographics, cervical angina pain location, pathology and duration of symptoms, treatment and/or management method, and posttreatment pain relief.RESULTSUpon careful screening, 22 articles published between 1976 and 2020 met the study’s inclusion/exclusion criteria, including 5 case series, 12 case reports, and 5 retrospective cohort studies. These studies featured a total of 1100 patients, of which 95 met inclusion criteria (mean patient age 51.7 years, age range 24–86 years; 53.6% male). Collectively, symptom durations ranged from 1.5 days to 90 months. Cervical herniation (72.6%) accounted for the majority of cervical angina cases, and surgical interventions (84.4%) predominated over physical therapy (13.0%) and medical management strategies (9.1%). Every patient assessed at follow-up reported relief from symptoms related to cervical angina.CONCLUSIONSCervical angina is a noncardiac syndrome of chest pain associated with a broad range of cervical and thoracic spinal pathologies, the most common of which is cervical disc herniation. Although difficult to diagnose, it can be successfully treated when identified through first-line conservative management or surgical interventions in refractory cases.
Translational Approaches to Electrical Stimulation for Peripheral Nerve Regeneration
Ransom, Seth C. , Lien, Brian V. , Brown, Nolan J. , Hanst, Brian , Lehrich, Brandon M. , Sahyouni, Ronald , Hanst, Brian , Ransom, R Chase, Shahrestani, Shane , Tafreshi, Ali R., Ransom, Ryan C.

Neurorehabilitation and Neural Repair | October 11, 2020 | Volume: 34 | Issue: 11 | Pages: 979-985

10.1177/1545968320962508 Get It

Background Achieving functional repair after peripheral nerve injury (PNI) remains problematic despite considerable advances in surgical technique. Therein, questions lie regarding the variable capacity of peripheral nerves to regenerate based on environmental influence. In-depth analyses of multiple therapeutic strategies have ensued to overcome these natural obstacles. Of these candidate therapies, electrical stimulation has emerged a frontrunner. Extensive animal studies have reported the ability of brief intraoperative electrical stimulation (BES) to enhance functional regeneration after PNI. Despite these reports, the exact mechanisms by which BES enhances regeneration and its effects on long nerve lesions are largely unknown. Indeed, clinical translation of this seemingly simple therapeutic has not been so simple, but a few studies performed in humans have yielded highly encouraging results. Objective We aimed to help bridge this translational gap by presenting the latest clinical trials on electrical stimulation for PNIs in combination with relevant etiologies, treatments and nonclinical findings. Methods To do so, a systematic search was performed on PubMed, IEEE, and Web of Science databases up to February 2020 using keywords significant to our study. References of each manuscript were screened for additional manuscripts of relevance to our study. Results We found multiple BES clinical studies reporting enhanced functional recovery or increased nerve regeneration. Although improved outcomes were reported, high variability after BES is seen between and within species likely due to injury severity, location and timeline along with other factors. Conclusion Further clinical studies and introduction of novel delivery platforms are vital to uncover the true regenerative potential of electrical stimulationtherapy.
The role of frailty in geriatric cranial neurosurgery for primary central nervous system neoplasms
Lehrich, Brandon M. , Brown, Nolan J. , Lien, Brian V. , Ransom, Seth C. , Ballatori, Alexander M. , Chen, Xiao T. , Sahyouni, Ronald , Ransom, Ryan C, Shahrestani, Shane , Tafreshi, Ali R., Ransom, Ryan C., Ton, Andy

Neurosurgical Focus | October 1, 2020 | Volume: 49 | Issue: 4 | Pages: E15

10.3171/2020.7.focus20426 Get It

OBJECTIVE Frailty is a clinical state of increased vulnerability due to age-associated decline and has been well established as a perioperative risk factor. Geriatric patients have a higher risk of frailty, higher incidence of brain cancer, and increased postoperative complication rates compared to nongeriatric patients. Yet, literature describing the effects of frailty on short- and long-term complications in geriatric patients is limited. In this study, the authors evaluate the effects of frailty in geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm. METHODS The authors conducted a retrospective cohort study of geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm between 2010 and 2017 by using the Nationwide Readmission Database. Demographics and frailty were queried at primary admission, and readmissions were analyzed at 30-, 90-, and 180-day intervals. Complications of interest included infection, anemia, infarction, kidney injury, CSF leak, urinary tract infection, and mortality. Nearest-neighbor propensity score matching for demographics was implemented to identify nonfrail control patients with similar diagnoses and procedures. The analysis used Welch two-sample t-tests for continuous variables and chi-square test with odds ratios. RESULTS A total of 6713 frail patients and 6629 nonfrail patients were identified at primary admission. At primary admission, frail geriatric patients undergoing cranial neurosurgery had increased odds of developing acute posthemorrhagic anemia (OR 1.56, 95% CI 1.23–1.98; p = 0.00020); acute infection (OR 3.16, 95% CI 1.70–6.36; p = 0.00022); acute kidney injury (OR 1.32, 95% CI 1.07–1.62; p = 0.0088); urinary tract infection prior to discharge (OR 1.97, 95% CI 1.71–2.29; p < 0.0001); acute postoperative cerebral infarction (OR 1.57, 95% CI 1.17–2.11; p = 0.0026); and mortality (OR 1.64, 95% CI 1.22–2.24; p = 0.0012) compared to nonfrail geriatric patients receiving the same procedure. In addition, frail patients had a significantly increased inpatient length of stay (p < 0.0001) and all-payer hospital cost (p < 0.0001) compared to nonfrail patients at the time of primary admission. However, no significant difference was found between frail and nonfrail patients with regard to rates of infection, thromboembolism, CSF leak, dural tear, cerebral infarction, acute kidney injury, and mortality at all readmission time points. CONCLUSIONS Frailty may significantly increase the risks of short-term acute complications in geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm. Long-term analysis revealed no significant difference in complications between frail and nonfrail patients. Further research is warranted to understand the effects and timeline of frailty in geriatric patients.
Enhancing peripheral nerve regeneration with neurotrophic factors and bioengineered scaffolds: A basic science and clinical perspective
Lien, Brian V. , Brown, Nolan J. , Ransom, Seth C. , Lehrich, Brandon M. , Sahyouni, Ronald , Ransom, Ryan C, Shahrestani, Shane , Tafreshi, Ali R., Ransom, Ryan C.

Journal of the Peripheral Nervous System | September 16, 2020 | Volume: 25 | Issue: 4 | Pages: 320-334

10.1111/jns.12414 Get It

AbstractDespite the peripheral nervous systems (PNS) capacity to regenerate, functional restoration is highly variable following peripheral nerve injury (PNI), oftentimes leading to persistent functional deficits. In the preclinical arena, advances in the therapeutic use of exogenous neurotrophic factors and synthetic neural scaffold technology hold promise in augmenting endogenous PNS regeneration following PNI. Clinical trials utilizing neurotrophic factors for other indications (eg, peripheral neuropathy) may provide insight into their role in PNI. Here we provide an updated review of progress made toward enhancing regeneration after PNI with a focus on neurotrophic factors and bioengineered scaffolds.