Clinical outcomes of peripheral nerve interfaces for rehabilitation in paralysis and amputation: a literature review.

Peripheral nerve interfaces (PNIs) are electrical systems designed to integrate with peripheral nerves in patients, such as following central nervous system (CNS) injuries to augment or replace CNS control and restore function. We review the literature for clinical trials and studies containing clinical outcome measures to explore the utility of human applications of PNIs. We discuss the various types of electrodes currently used for PNI systems and their functionalities and limitations. We discuss important design characteristics of PNI systems, including biocompatibility, resolution and specificity, efficacy, and longevity, to highlight their importance in the current and future development of PNIs. The clinical outcomes of PNI systems are also discussed. Finally, we review relevant PNI clinical trials that were conducted, up to the present date, to restore the sensory and motor function of upper or lower limbs in amputees, spinal cord injury patients, or intact individuals and describe their significant findings. This review highlights the current progress in the field of PNIs and serves as a foundation for future development and application of PNI systems.

Degenerative Cervical Myelopathy: A Concept Review and Clinical Approach.

STUDY DESIGN: Narrative review. OBJECTIVE: To provide an overview of the evaluation and diagnosis of degenerative cervical myelopathy (DCM). SUMMARY OF BACKGROUND DATA: DCM describes several etiologies of degenerative, nontraumatic spinal cord impairment. Early diagnosis and intervention can decrease neurological decline. METHODS: An extensive literature review was conducted. RESULTS: The incidence and prevalence of DCM are increasing worldwide. Asymptomatic spinal cord compression can progress to cervical myelopathy. Static and dynamic factors contribute to spinal cord compression. Patients frequently present with decreased manual dexterity, gait instability, and neck pain. On physical exam, patients frequently present with upper motor neuron signs, a Lhermitte sign, a failed Romberg test, global proprioceptive dysfunction, and decreased pain sensation. Anatomic variation may complicate physical exam interpretation. The modified Japanese Orthopaedic Association Scale and Nurick Classification, based on functional impairment, provide diagnostic utility. Magnetic Resonance Imaging imaging is useful in narrowing the differential diagnosis, evaluating the severity of neurological impairment, and predicting disease progression. CONCLUSIONS: Understanding the pathophysiology of DCM and the diagnostic utility of the signs and symptoms of DCM is critical. The decision for anterior cervical discectomy and fusion (ACDF), laminoplasty, or combined ACDF and posterior cervical fusion is individualized for each patient.

Treatment of Intrathecal Drug Pump Flipping Using Fascial Flaps: A Technical Description and Case Series.

BACKGROUND AND OBJECTIVES: Intrathecal drug therapy is a common treatment for dystonia, pain, and spasticity using implanted pump and catheter systems. Standardized management of intrathecal drug pump (ITDP) migration and flipping has not been well established in the literature. This study reports the use of soft tissue to address less common pump complications such as pump flipping, migration, and difficulty in medication refill. METHODS: A retrospective chart review of intrathecal pump cases performed by two surgeons between February 2020 and August 2022 was conducted. Patients with complications such as pump flipping, migration, or challenges in medication refill treated with soft tissue flaps were included. Patient demographics, comorbidities, and perioperative data were collected. RESULTS: A total of five patients with ITDP complicated by pump flipping, migration, malposition, or difficulty in medication refill that were treated using fascial flaps were included in the study. Three technical considerations when revising ITDP complications are secure pump anchoring, reliable wound closure, and ease of pump medication refill. Cases 1 and 2 demonstrate the technique of secure pump anchoring with a rectus fascial flap. Cases 3 and 4 show a technique to achieve reliable vascularized wound closure, and case 5 describes a technique to solve an uncommon problem of a thick subcutaneous abdominal tissue preventing the refill of the ITDP medication. CONCLUSION: Soft tissue flaps may serve as a treatment option for patients with uncommon ITDP complications. De-epithelialized dermal fasciocutaneous or fascial flaps may be developed to anchor the pump more securely. Cross-discipline collaboration may further delineate the technique, benefits, and outcomes of this approach.

Spinal cord stimulation for chronic pain treatment following sacral chordoma resection: illustrative case.

BACKGROUND: Cancer-related or postoperative pain can occur following sacral chordoma resection. Despite a lack of current recommendations for cancer pain treatment, spinal cord stimulation (SCS) has demonstrated effectiveness in addressing cancer-related pain. OBSERVATIONS: A 76-year-old female with a sacral chordoma underwent anterior osteotomies and partial en bloc sacrectomy. She subsequently presented with chronic pain affecting both buttocks and posterior thighs and legs, significantly impeding her daily activities. She underwent a staged epidural SCS paddle trial and permanent system placement using intraoperative neuromonitoring. The utilization of percutaneous leads was not viable because of her history of spinal fluid leakage, multiple lumbosacral surgeries, and previous complex plastic surgery closure. The patient reported a 62.5% improvement in her lower-extremity pain per the modified Quadruple Visual Analog Scale and a 50% improvement in the modified Pain and Sleep Questionnaire 3-item index during the SCS trial. Following permanent SCS system placement and removal of her externalized lead extenders, she had an uncomplicated postoperative course and reported notable improvements in her pain symptoms. LESSONS: This case provides a compelling illustration of the successful treatment of chronic pain using SCS following radical sacral chordoma resection. Surgeons may consider this treatment approach in patients presenting with refractory pain following spinal tumor resection.

Internal iliac artery aneurysm masquerading as a sciatic nerve schwannoma: illustrative case.

BACKGROUND: Schwannomas are common peripheral nerve sheath tumors. Imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) can help to distinguish schwannomas from other types of lesions. However, there have been several reported cases describing the misdiagnosis of aneurysms as schwannomas. OBSERVATIONS: A 70-year-old male with ongoing pain despite spinal fusion surgery underwent MRI. A lesion was noted along the left sciatic nerve, which was believed to be a sciatic nerve schwannoma. During the surgery for planned neurolysis and tumor resection, the lesion was noted to be pulsatile. Electromyography mapping and intraoperative ultrasound confirmed vascular pulsations and turbulent flow within the aneurysm, so the surgery was aborted. A formal CT angiogram revealed the lesion to be an internal iliac artery (IIA) branch aneurysm. The patient underwent coil embolization with complete obliteration of the aneurysm. LESSONS: The authors report the first case of an IIA aneurysm misdiagnosed as a sciatic nerve schwannoma. Surgeons should be aware of this potential misdiagnosis and potentially use other imaging modalities to confirm the lesion before proceeding with surgery.

Can Nutritional Supplements Benefit Patients With Nonalcoholic Steatohepatitis and Nonalcoholic Fatty Liver Disease?

A characteristic of nonalcoholic fatty liver disease (NAFLD) is the buildup of excess fat in the liver which encompasses various clinical phases, including steatosis, inflammation, ballooning, fibrosis, and liver cirrhosis. Nonalcoholic steatohepatitis (NASH) represents a severe form of NAFLD. The prevalence of NAFLD, particularly NASH, is notably high among Hispanics and those with morbid obesity. Diabetes, obesity, and dyslipidemia are significant risk factors in patients with NAFLD. The pathogenesis of NAFLD involves complex interactions between hormonal, nutritional, and genetic factors. Different clinical trials have been conducted to determine if there are any supplements that could help patients with NASH. Evidence has shown that vitamin E decreased the NAFLD activity score but not fibrosis. Our review summarizes the influence of supplementation on patients with NAFLD and NASH, focusing on the use of different clinical trials, systematic reviews, and meta-analyses. In the future, patients and physicians will play crucial roles in exploring diverse approaches and finding effective solutions to address this growing issue.

Response to Letter Regarding "Predictive Value of Preoperative Serum Albumin in Patients With Metastatic Spine Diseases: A Statistical Comment".

We thank the authors for their interest in and commentary on "Preoperative Serum Albumin Level Predicts Length of Stay and Perioperative Adverse Events Following Vertebral Corpectomy and Posterior Stabilization for Metastatic Spine Disease." We appreciate the opportunity to respond to their comments herein.

Magnetic Resonance-Guided Stereotaxy for Infusions to the Pig Brain.

The overall goal of this procedure is to perform stereotaxy in the pig brain with real-time magnetic resonance (MR) visualization guidance to provide precise infusions. The subject was positioned prone in the MR bore for optimal access to the top of the skull with the torso raised, the neck flexed, and the head inclined downward. Two anchor pins anchored on the bilateral zygoma held the head steady using the head holder. A magnetic resonance imaging (MRI) flex-coil was placed rostrally across the head holder so that the skull was accessible for the intervention procedure. A planning grid placed on the scalp was used to determine the appropriate entry point of the cannula. The stereotactic frame was secured and aligned iteratively through software projection until the projected radial error was less than 0.5 mm. A hand drill was used to create a burr hole for insertion of the cannula. A gadolinium-enhanced co-infusion was used to visualize the infusion of a cell suspension. Repeated T1-weighted MRI scans were registered in real time during the agent delivery process to visualize the volume of gadolinium distribution. MRI-guided stereotaxy allows for precise and controlled infusion into the pig brain, with concurrent monitoring of cannula insertion accuracy and determination of the agent volume of distribution.

Preoperative Serum Albumin Level Predicts Length of Stay and Perioperative Adverse Events Following Vertebral Corpectomy and Posterior Stabilization for Metastatic Spine Disease.

STUDY DESIGN: Retrospective review of a prospectively collected national database. OBJECTIVES: To determine the association between preoperative serum albumin levels and perioperative adverse events (AEs) following vertebral corpectomy and posterior stabilization for metastatic spine disease. METHODS: The 2010 to 2019 American College of Surgeons' National Surgical Quality Improvement (ACS-NSQIP) database was used to identify all patients undergoing vertebral corpectomy and posterior stabilization for metastatic spine disease. Receiver operative characteristic (ROC) curve analysis was used to determine preoperative serum albumin cut-off values for predicting perioperative AEs. Low preoperative serum albumin was defined as serum albumin below this cut-off value. RESULTS: A total of 301 patients were included in the study. ROC curve analysis demonstrated serum albumin < 3.25 g/dL as a cut-off value for predicting perioperative AEs. The low serum albumin group had a higher overall perioperative AEs (P = .041), longer post-operative LOS (P < .001), higher 30-day reoperation rate (P = .014), and a higher in-hospital mortality rate (P = .046). Multivariate analysis demonstrated that low preoperative serum albumin was associated with higher perioperative AEs. CONCLUSIONS: Low serum albumin level is associated with higher perioperative AEs, longer postoperative LOS, and higher rates of 30-day reoperation and in-hospital mortality among patients undergoing vertebral corpectomy and posterior stabilization for metastatic spine disease. Strategies to improve preoperative nutritional status in patients undergoing this procedure may improve these perioperative outcome measures within this surgical population. LEVEL OF EVIDENCE: III.

Incorporating Intraoperative Mechanomyography to Peripheral Nerve Decompression Surgery.

BACKGROUND: Mechanomyography (MMG) is a novel intraoperative tool to detect and quantify nerve activity with high sensitivity as compared with traditional electromyographic recordings. MMG reflects the mechanical vibrations of single motor units detected through accelerometer sensors after direct motor neuron stimulation. OBJECTIVE: To determine the feasibility of applying intraoperative MMG during peripheral nerve surgery. METHODS: A total of 20 consecutive patients undergoing surgical decompression of the ulnar nerve at the cubital tunnel or common peroneal nerve at the fibular head were included in this study. Intraoperatively, the common peroneal and ulnar nerves were directly stimulated through the MMG electrode probe starting at 0.1 mA threshold and increasing by 0.1 mA increments until target muscle activity was noted. The lowest threshold current required to elicit a muscle response was recorded before decompression and after proximal and distal nerve decompression. RESULTS: Of the patients, 80% (16/20) had MMG signals detected and recorded. Four patients were unable to have MMG signal detected despite direct nerve visualization and complete neurolysis. The mean predecompression stimulus threshold was 1.59 ± 0.19 mA. After surgical decompression, improvement in the mean MMG stimulus threshold was noted (0.47 ± 0.03 mA, P = .0002). Postoperatively, all patients endorsed symptomatic improvement with no complications. CONCLUSION: MMG may provide objective guidance for the intraoperative determination of the extent of nerve decompression. Lower stimulus thresholds may represent increased sparing of axonal tissue. Future work should focus on validating normative values of MMG stimulus thresholds in various nerves and establishing clinical associations with functional outcomes.

Defining the Mortality Rate of Elderly Trauma Patients With Operative Feeding Tubes.

INTRODUCTION: Placement of feeding tubes in elderly patients has not been studied in elderly trauma patients. The objectives of this study were to determine in-hospital mortality in elderly trauma patients receiving operative feeding tubes and to identify factors associated with in-hospital mortality. METHODS: A retrospective study utilizing 2017 National Trauma Data Bank data was conducted. Trauma patients aged 65 and older with operative feeding tubes were included. Demographic, injury, comorbidity, and general hospital course data were analyzed. Two cohorts were constructed: survival and non-survival to hospital discharge. Bivariate analysis and logistic regression were performed to determine factors independently associated with in-hospital mortality. RESULTS: A total of 3,398 patients were analyzed with 331 (9.7%) dying during hospitalization. Patients had a median age of 75 years and sustained severe injuries (median ISS 17). Patients who died were older (76 vs. 75 years, p = .03), more severely injured (ISS 22 vs. 17, p < .001), had a higher geriatric trauma outcome score (134 vs. 121, p < .001), and had lower rates of dementia (8 vs. 13%, p = .01). Multivariate regression showed male sex, lower admission GCS, higher Charlson Comorbidity Index, and an Advance Directive Limiting Care (ADLC) were independently associated with in-hospital mortality. Dementia diagnosis was negatively associated with in-hospital mortality. CONCLUSIONS: The in-hospital mortality rate for elderly trauma patients with operative feeding tubes placed was notably high. Identifying factors associated with in-hospital mortality will serve to assist providers in counseling patients and caregivers about the outcomes of operative feeding tube placement in this patient population.

In-hospital, 30- and 90-day mortality in elderly trauma patients with operative feeding tubes.

BACKGROUND: Nutrition is essential in the treatment of elderly trauma patients (ETP). ETP experience dysphagia at rates six times higher than the non-trauma elderly population (NTEP) and are at increased risk for malnutrition. Operative feeding tube (OFT) placement is often used to aid with the nutritional management of ETP. Elderly patients experience higher rates of morbidity and mortality when compared to the general population, especially in the traumatic setting, with some data suggesting in-hospital mortality as high as 10%. However, the mortality rates and associated comorbidities associated with OFT in ETP are unknown. The purposes of this study were to establish the mortality rate in hospital as well as 30- and 90-days following discharge among elderly trauma patients (ETP) receiving OFT, and to assess factors associated with mortality within this population. METHODS: A retrospective review of all trauma patients from a single Level I Trauma Center from 01/2010-09/2020 was conducted. Exclusion criteria were patients under 65 years of age or those with previously placed OFT. Demographics, comorbidities, injury mechanisms, injury severity scores (ISS), and OFT data were collected from the institutional trauma registry. Mortality data were obtained using the Social Security Death Index. Mortality at discharge, 30 days, and 90 days following discharge were the primary outcomes. Bivariate analysis was conducted to compare characteristics and comorbidities of patients alive and dead at the time points of interest. RESULTS: There were 151 ETP who received OFT. Patients were largely male (67.5%), severely injured via a blunt mechanism (95%), and had a median age of 76 years. 11 (7.3%) experienced in-hospital mortality following feeding tube placement, 21 (13.9%) died within 30 days, and 31 (20.5%) within 90 days. Bivariate analysis demonstrated that ETP who died were more likely to have a history of dementia (p = 0.004), congestive heart failure (p = 0.014), and end-stage liver disease (p = 0.034). No other patient or injury factors were associated with mortality after OFT placement. CONCLUSION: Mortality rates for ETP with OFT were higher than anticipated, yet favorable compared to recently reported data. Patients who died were more likely to have dementia, CHF, or ESLD than those who survived. The few comorbidities associated with mortality suggest that nearly all ETP who undergo OFT placement are at risk for mortality. Additionally, the data highlights the importance of early goals of care discussions for ETP and their loved ones when operative feeding tubes are being considered. LEVEL OF EVIDENCE: Level III. STUDY TYPE: Prognostic/Therapeutic/Diagnostic Test/Economic/Decision.

Melanoma metastasis to the femoral nerve: a novel case of melanoma masquerading as mononeuropathy. Illustrative case.

BACKGROUND: Metastatic cancer may involve the central and peripheral nervous system, usually in the late stages of disease. At this point, most patients have been diagnosed and treated for widespread systemic disease. Rarely is the involvement of the peripheral nervous system the presenting manifestation of malignancy. One reason for this is a proposed "blood-nerve barrier" that renders the nerve sheath a relatively privileged site for metastases. OBSERVATIONS: The authors presented a novel case of metastatic melanoma presenting as intractable leg pain and numbness. Further workup revealed concurrent disease in the brain and breast, prompting urgent treatment with radiation and targeted immunotherapy. LESSONS: This case highlights the rare presentation of metastatic melanoma as a mononeuropathy. Although neurological complications of metastases tend to occur in later stages of disease after initial diagnosis and treatment, one must remember to consider malignancy in the initial differential diagnosis of mononeuropathy.

Demographic and economic trends in vertebral fracture surgeries throughout the United States.

Background: Vertebral fractures, frequently resulting from high-impact trauma to the spine, are an increasingly relevant public health concern. Little is known about the long-term economic and demographic trends affecting patients undergoing surgery for such fractures. This study examines national economic and demographic trends in vertebral fracture surgery in the United States to improve value-based care and health care utilization. Methods: The National Inpatient Sample (NIS) was queried for patients who underwent surgical treatment of a vertebral fracture (ICD-9-CM-3.53) (excluding kyphoplasty and vertebroplasty) between 1993 and 2015. Demographic data included patient age, sex, income, insurance type, hospital size, and location. Economic data including aggregate charge, aggregate cost, hospital cost, and hospital charge were analyzed. Results: The number of vertebral fracture surgeries, excluding kyphoplasty and vertebroplasty, increased 461% from 3,331 in 1993 to 18,675 in 2014, while inpatient mortality increased from 1.9% to 2.5%.The mean age of patients undergoing vertebral fracture surgeries increased from 42 in 1993 to 53 in 2015. The aggregate cost of surgery increased from $189,164,625 in 2001 to $1,060,866,580 in 2014, a 461% increase. Conclusions: The significant increase in vertebral fracture surgeries between 1993 and 2014 may reflect an increased rate of fractures, more surgeons electing to treat fractures surgically, or a combination of both. The increasing rate of vertebral fracture surgery, coupled with increasing hospital costs and mortality, signifies that the treatment of vertebral fractures remains a challenging issue in healthcare. Further research is necessary to determine the underlying cause of both the increase in surgeries and the increasing mortality rate.

Improvement in sagittal alignment and mechanical low-back pain following deep brain stimulation for Parkinson's disease: illustrative case.

BACKGROUND: Parkinson's disease (PD) is a common neurogenerative disease marked by the characteristic triad of bradykinesia, rigidity, and tremor. A significant percentage of patients with PD also demonstrate postural abnormalities (camptocormia) that limit ambulation and accelerate degenerative pathologies of the spine. Although deep brain stimulation (DBS) is a well-established treatment for the motor fluctuations and tremor seen in PD, the efficacy of DBS on postural abnormalities in these patients is less clear. OBSERVATIONS: The authors present a patient with a history of PD and prior lumbosacral fusion who underwent bilateral subthalamic nucleus DBS and experienced immediate improvement in sagittal alignment and subjective relief of mechanical low-back pain. LESSONS: DBS may improve postural abnormalities seen in PD and potentially delay or reduce the need for spinal deformity surgery.

Jejunojejunal intussusception of a sutured enterotomy site after takedown and primary repair of persistent enterocutaneous fistula: a case report.

Enterocutaneous fistula (ECF) is a common complication of many abdominal surgeries. Although most ECF resolve spontaneously, there are many factors that can lead to persistence of the fistula. Management of persistent enterocutaneous fistula usually involves surgery with recurrence of fistula being the most common complication. Here we describe a case of 67-year-old female who presented with intussusception following repair of a persistent enterocutaneous. Given the rare finding of intussusception in adults, this case report presents an interesting complication.

Acute aortic occlusion leading to spinal cord ischemia in a 73-year-old: A case report.

Background: Cauda equina syndrome (CES) is typically caused by a compressive etiology from a herniated disk, tumor, or fracture of the spine compressing the thecal sac. Here, we report a CES mimic - acute aortic occlusion (AAO), a rare disease that is associated with high morbidity and mortality. AAO can compromise spinal cord blood supply and leads to spinal cord ischemia. Case Description: Our patient presented with an acute onset of bilateral lower extremity pain and weakness with bowel/bladder incontinence, a constellation of symptoms concerning for CES. However, on initial imaging, there was no compression of his thecal sac to explain his symptomology. Further, investigation revealed an AAO. The patient underwent an emergent aortic thrombectomy with resolution of symptoms. Conclusion: AAO can mimic CES and should be considered in one's differential diagnosis when imaging is negative for any spinal compressive etiologies.