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Scholarly Works (68 results)

  • Thesis
  • Peer Reviewed
UC Irvine Electronic Theses and Dissertations (2018)

Neuroprosthetic devices have become increasingly important in the treatment of clinical pathologies. In particular, the application of neuroprosthetic devices to restore function following damage to peripheral and cranial nerves has been demonstrated to be efficacious, safe, and has been readily adopted in the clinic to treat a wide range of pathologies. Neuroprosthetic devices have been successfully deployed in numerous cranial nerves, including the hypoglossal nerve to treat obstructive sleep apnea and the vagus nerve to treat epilepsy, heart failure, and manage blood pressure. However, the application of neuroprosthetic devices to the facial nerve (FN) for purposes of facial reanimation has not been explored.

FN injury can cause debilitating and permanent damage with oftentimes limited treatment options. In cases of FN injury, patients may develop permanent facial paralysis (FP), which can cause facial muscles to lose tone, and over time, atrophy and convert into scar tissue. FP arises from a variety of causes, including tumor, surgery, trauma or infection, and results in problems with eye irritation, visual impairment, drooling, intraoral food retention, and demoralizing cosmetic deformities.

In recent decades, considerable efforts have been undertaken to care for patients with permanent FP. Several surgical interventions, including static and dynamic options, have been described for patients with unilateral FP. However, these interventions only address specific parts of the face, have a 10-15% failure rate, and require multiple procedures involving multiple surgical sites to accomplish functional goals. An alternative approach to facial reanimation is the utilization of neuroprosthetic technologies to deliver exogenous current to the partially recovered FN in order to provide both facial tone and selective activation of individual muscles.

We demonstrate the ability of both multichannel microelectrode arrays and multichannel cuff electrodes to selectively stimulate the feline FN in both acute and chronic settings, and couple this technology with closed loop circuitry to develop a putative approach to volitional and graded hemifacial animation. We also present data from clinical investigations on human FN selectivity, and investigate the application of these technologies in the recurrent laryngeal nerve.

    Cover page: Neuroprosthetic Approaches to Selective Facial Nerve StimulationCreative Commons 'BY' version 4.0 license
    • Article
    • Peer Reviewed
    UC Irvine Previously Published Works (2019)

    Background

    Ventriculoperitoneal shunts (VPSs) have been the mainstay of treating hydrocephalus since the 1950s. However, shunts have a reported complication rate reaching nearly 50%. Devices have been developed that utilize noninvasive thermal transcutaneous diffusion technology. These shunt evaluation devices measure temperature gradients to detect shunt cerebrospinal fluid flow. We assessed the utility using a thermal diffusion technique to work up shunt failure in the emergency room (ER).

    Methods

    This was a retrospective case series at a single medical center ER. We included consecutive patients with possible VPS malfunction who were evaluated with a thermal sensor. The time period of data collection included September 2015-April 2018.

    Results

    Eight patients were reviewed, including four males and four females. The average age of reviewed patients was 35.1 (+/- ; 16.5). In our case series, three patients had adequate shunt flow as assessed by the shunt evaluation device, and the decision was made to discharge the patient and follow-up in clinic. In two patients, the flow was diminished, but due to other reassuring signs, the patients were still discharged with follow-up. Two patients were noted to have poor flow and were admitted for shunt revision.

    Conclusion

    It is important to determine whether a malfunction is present and whether an intervention is necessary for patients who present to the emergency department with possible symptoms of shunt failure. A thermal sensor is a fast and noninvasive tool in the evaluation of shunt flow and helps determine whether it is safe to send a patient home or intervene appropriately.
      Cover page: Noninvasive thermal evaluation for shunt failure in the emergency room
      • Article
      • Peer Reviewed
      UC Irvine Previously Published Works (2019)
      BACKGROUND: Ventriculoperitoneal shunts (VPSs) have been the mainstay of treating hydrocephalus since the 1950s. However, shunts have a reported complication rate reaching nearly 50%. Devices have been developed that utilize noninvasive thermal transcutaneous diffusion technology. These shunt evaluation devices measure temperature gradients to detect shunt cerebrospinal fluid flow. We assessed the utility using a thermal diffusion technique to work up shunt failure in the emergency room (ER). METHODS: This was a retrospective case series at a single medical center ER. We included consecutive patients with possible VPS malfunction who were evaluated with a thermal sensor. The time period of data collection included September 2015-April 2018. RESULTS: Eight patients were reviewed, including four males and four females. The average age of reviewed patients was 35.1 (+/- ; 16.5). In our case series, three patients had adequate shunt flow as assessed by the shunt evaluation device, and the decision was made to discharge the patient and follow-up in clinic. In two patients, the flow was diminished, but due to other reassuring signs, the patients were still discharged with follow-up. Two patients were noted to have poor flow and were admitted for shunt revision. CONCLUSION: It is important to determine whether a malfunction is present and whether an intervention is necessary for patients who present to the emergency department with possible symptoms of shunt failure. A thermal sensor is a fast and noninvasive tool in the evaluation of shunt flow and helps determine whether it is safe to send a patient home or intervene appropriately.
        Cover page: Noninvasive thermal evaluation for shunt failure in the emergency room.
        • Article
        • Peer Reviewed
        ICTS Publications (2017)

        Permanent injury to the cranial nerves can often result in a substantial reduction in quality of life. Novel and innovative interventions can help restore form and function in nerve paralysis, with bioelectric interfaces among the more promising of these approaches. The foreign body response is an important consideration for any bioelectric device as it influences the function and effectiveness of the implant. The purpose of this review is to describe tissue and functional effects of chronic neural implantation among the different categories of neural implants and highlight advances in peripheral and cranial nerve stimulation.Data Sources: PubMed, IEEE, and Web of Science literature search.Review Methods: A review of the current literature was conducted to examine functional and histologic effects of bioelectric interfaces for neural implants.

        Bioelectric devices can be characterized as intraneural, epineural, perineural, intranuclear, or cortical depending on their placement relative to nerves and neuronal cell bodies. Such devices include nerve-specific stimulators, neuroprosthetics, brainstem implants, and deep brain stimulators. Regardless of electrode location and interface type, acute and chronic histological, macroscopic and functional changes can occur as a result of both passive and active tissue responses to the bioelectric implant.

        A variety of chronically implantable electrodes have been developed to treat disorders of the peripheral and cranial nerves, to varying degrees of efficacy. Consideration and mitigation of detrimental effects at the neural interface with further optimization of functional nerve stimulation will facilitate the development of these technologies and translation to the clinic.

        3.

          Cover page: Functional and Histological Effects of Chronic Neural Electrode Implantation.Creative Commons 'BY' version 4.0 license
          • Article
          • Peer Reviewed
          UC Irvine Previously Published Works (2018)
          BACKGROUND: Neurosurgery inpatients are oftentimes critically ill, and face significant stress, post-operative pain, and/or emotional distress. As a result, the use of non-pharmacologic, alternative therapies as adjuncts in surgical care may benefit this patient population. Hospital economics related to integrative services may also provide additional incentive to providing alternative therapies. This study characterizes and evaluates how Integrative Healing Services (IHS) affects patient pain levels and length of stay. We also performed a literature review to examine national trends in inpatient integrative healing. METHODS: An IHS team (e.g. acupuncture, healing touch, music therapy, pet therapy, and counseling) was incorporated into the treatment regimen of neurosurgery inpatients (with >4days of stay) with chronic or intractable pain, stress or depression, and/or patients intolerant to or who failed physical or occupational therapy. RESULTS: 34 charts were retrospectively reviewed, with 17 patients receiving IHS (11 cranial and 6 spine cases), and 17 age and gender matched controls receiving routine care (11 cranial and 6 spine patients). Overall, 71% (12/17) of patients had a reduction in pain medication consumption, with 55% (6/11) of cranial and 100% (6/6) of spine patients reporting a reduction compared to baseline. The average pre-treatment pain-scale score was 5.5 out of 10 across all patients, while the average post-treatment pain-scale score was 3 out of 10 (p<0.01). 59% of patients had improved mobility. The average length of stay in the IHS group was 12.6days, and 19.6days in the routine care group (range 4-45) (p<0.01). CONCLUSIONS: IHS intervention may be an effective option for treating pain and decreasing hospital length of stay. National trends support the use of integrative healing and will likely continue to increase as further studies are performed.
            Cover page: A novel integrative healing services approach for neurosurgery inpatients: Preliminary experiences and cost calculations.
            • Article
            • Peer Reviewed
            UC Irvine Previously Published Works (2020)

            Background

            Pancreatic ductal adenocarcinoma (PDAC) is the most common pancreatic malignancy, which rarely metastasizes to the spine.

            Case description

            Here, we present a lytic lumbar metastatic PDAC resulting in severe epidural spinal cord compression (ESCC) with instability. The lesion required preoperative particle embolization, surgical decompression, and fusion.

            Conclusion

            This case report shows that PDAC may metastasize to the lumbar spine requiring routine decompression with fusion.
              Cover page: Metastatic epidural spinal column compression due to pancreatic ductal adenocarcinoma causing subacute Cauda equina syndrome: A case report
              • Article
              • Peer Reviewed
              UC Irvine Previously Published Works (2018)
              Permanent facial paralysis and paresis (FP) results from damage to the facial nerve (FN), and is a debilitating condition with substantial functional and psychological consequences for the patient. Unfortunately, surgeons have few tools with which they can satisfactorily reanimate the face. Current strategies employ static (e.g., implantation of nonmuscular material in the face to aid in function/cosmesis) and dynamic options (e.g., gracilis myoneurovascular free tissue transfer) to partially restore volitional facial function and cosmesis. Here, we propose a novel neuroprosthetic approach for facial reanimation that utilizes electromyographic (EMG) input coupled to a chronically implanted multichannel cuff electrode (MCE) to restore instantaneous, volitional, and selective hemifacial movement in a feline model. To accomplish this goal, we developed a single-channel EMG-drive current source coupled with a chronically implanted MCE via a portable microprocessor board. Our results demonstrated a successful feasibility trial in which human EMG input resulted in FN stimulation with subsequent concentric contraction of discrete regions of a feline face.
                • Article
                • Peer Reviewed
                UC Irvine Previously Published Works (2017)
                Traumatic Brain Injury (TBI) is a devastating and widely prevalent cause of death and disability in the United States. Educational interventions integrated into neurosurgical neurotrauma clinics can facilitate patient education and optimize the clinical encounter. Interactive educational modalities may enhance knowledge acquisition and patient satisfaction, however, no description of implementing such a program has been presented in the literature. The implementation of an interactive iBook-based educational intervention in an outpatient neurotrauma clinic is discussed. Concussion and TBI iBooks and surveys were created. Then, a retrospective chart review and data analysis of 202 consecutive patients and family members presenting to the neurotrauma clinic was conducted. The participants completed a presurvey, reviewed an interactive iBook, and then completed a post-survey to test interim knowledge improvement. We discuss the process and problems encountered when creating the iBooks and implementing them in a clinical setting. Between August 1, 2015 and August 1, 2016, 93 patients (46%) and 109 (54%) family members participated in the study, for a total of 202 participants. 104 subjects reviewed a concussion iBook, and 98 subjects reviewed a TBI iBook, depending on their medical condition. Significant improvements in self-reported knowledge measures were demonstrated. Participants ranged in age from 10 to 90 years, with a mean of 45 years. The male to female ratio was 1.104:1. Interactive iBooks were readily implemented into a neurotrauma clinic. Improvements in self-reported knowledge measures and strong preference for the interactive iBook were attributed to the efficacy of the educational intervention. Examples of how interactive iBooks may be a useful adjunct in the education of head injury patients and their families in the neurotrauma setting are presented.
                  Cover page: Implementation of an Interactive Tablet-based Educational Intervention in the Neurotrauma Clinic: A 1-year Retrospective Analysis.
                  • Article
                  • Peer Reviewed
                  UC Irvine Previously Published Works (2016)
                  Split-thickness skin graft (STSG) continues to be the preferred means of external auditory canal (EAC) reconstruction. We thus sought to describe our experience using skin from the posterior aspect of the auricle (SPAA) as a donor site in EAC reconstruction. Grafts were, on average, 5 × 10 mm in size and obtained with a No. 10 blade after tumescence injection. The cases of 39 patients who underwent 41 procedures were retrospectively reviewed. Of the 38 patients with both 3- and 6-month follow-ups, no postoperative stenosis or bony exposure occurred. STSG from the SPAA can be a good option in EAC reconstruction. Total EAC/tympanic membrane coverage can be obtained with STSG from the SPAA.
                    Cover page: Auricular Split-Thickness Skin Graft for Ear Canal Coverage.
                    • Article
                    • Peer Reviewed
                    UC Irvine Previously Published Works (2017)

                    Objective

                    To describe persistent post-stapedotomy vertigo (PSV) and its treatment using migraine prophylaxis.

                    Patients

                    A retrospective review of all patients with persistent PSV spanning 10 years at a tertiary academic hospital was performed. Patients who experienced persistent vertigo for a minimum of 3 months after surgery were included. Those with possible perilymph fistula, long prosthesis, and benign paroxysmal positional vertigo were excluded.

                    Interventions

                    All patients received instructions on migraine dietary and lifestyle changes and Vitamin B2 and magnesium. In addition, prophylactic treatment with nortriptyline, verapamil, or a combination thereof was started.

                    Main outcome measure

                    Changes in vertigo frequency was the main outcome variable. The secondary outcome variables included the time period and medications necessary to achieve symptomatic resolution.

                    Results

                    Four women and one man with an average age of 53 years were identified that met criteria for persistent PSV indicating an incidence of 0.9% at our institution. The onset of vertigo symptoms was on average 20 days postoperatively. All five patients had daily vertigo episodes and experienced complete resolution with no vertigo episodes after treatment. Symptomatic resolution was achieved over an average of 9 weeks after initiating treatments.

                    Conclusions

                    Persistent PSV beyond 3 months is a rare occurrence and its treatment can be challenging when there is no evidence of an underlying pathology. This subset of patients may be suffering from migraine, which was triggered postoperatively. Treatment with migraine prophylaxis in this cohort of patients may result in resolution of vertigo.
                      Cover page: Resolution of Persistent Post-Stapedotomy Vertigo With Migraine Prophylactic Medication.
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