Human-robot planar co-manipulation of extended objects: data-driven models and control from human-human dyads.

Human teams are able to easily perform collaborative manipulation tasks. However, simultaneously manipulating a large extended object for a robot and human is a difficult task due to the inherent ambiguity in the desired motion. Our approach in this paper is to leverage data from human-human dyad experiments to determine motion intent for a physical human-robot co-manipulation task. We do this by showing that the human-human dyad data exhibits distinct torque triggers for a lateral movement. As an alternative intent estimation method, we also develop a deep neural network based on motion data from human-human trials to predict future trajectories based on past object motion. We then show how force and motion data can be used to determine robot control in a human-robot dyad. Finally, we compare human-human dyad performance to the performance of two controllers that we developed for human-robot co-manipulation. We evaluate these controllers in three-degree-of-freedom planar motion where determining if the task involves rotation or translation is ambiguous.

Treating Chronic, Intractable Pain with a Miniaturized Spinal Cord Stimulation System: 1-Year Outcomes from the AUS-nPower Study During the COVID-19 Pandemic.

Purpose: Spinal cord stimulation (SCS) is a highly effective treatment for chronic neuropathic pain. Despite recent advances in technology, treatment gaps remain. A small SCS system with a miniaturized implantable pulse generator (micro-IPG; <1.5 cm3 in volume) and an externally worn power source may be preferred by patients who do not want a large, implanted battery. We report here the long-term outcomes from the first-in-human study evaluating the safety and performance of a new neurostimulation system. Patients and Methods: This was a prospective, multi-center, open-label, single-arm study to evaluate this SCS system, in the treatment of chronic, intractable leg and low-back pain. Consented subjects who passed screening continued on to the long-term phase of the study. One-year, patient-reported outcomes (PRO's) such as pain (Numeric Rating Scale, NRS), functional disability, quality of life, and mood were captured. Results: Twenty-six (26) evaluable subjects with permanent implants were included in this analysis. The average leg pain NRS score decreased from 6.8 ± 1.2 at baseline to 1.1 ± 1.2 at the end of the study (p < 0.001), while the average low-back pain NRS score decreased from 6.8 ± 1.2 to 1.5 ± 1.2 (p < 0.001). The responder rate (proportion with ≥50% pain relief) was 91% in the leg(s) and 82% in the low back. There were significant improvements in functional disability (Oswestry Disability Index) and in mood (Beck Depression Inventory), demonstrating a 46% and 62% improvement, respectively (p < 0.001). Eleven-point Likert scales demonstrated the wearable to be very comfortable and very easy to use. Conclusion: There were considerable challenges conducting a clinical study during the COVID-19 pandemic, such as missed study programming visits. Nevertheless, subjects had significant PRO improvements through 1-year. The small size of the implanted device, along with a proprietary waveform, may allow for improved SCS outcomes and a drop in incidence of IPG-pocket pain.

Early Experience With a Novel Miniaturized Spinal Cord Stimulation System for the Management of Chronic Intractable Pain of the Back and Legs.

INTRODUCTION: A novel, spinal cord stimulation (SCS) system with a battery-free miniaturized implantable pulse generator (IPG) was used in this feasibility study. The system uses an external power source that communicates bidirectionally with the IPG (< 1.5 cm3). Human factors, subject comfort, and effects on low back and leg pain were evaluated in this first-in-human study. MATERIALS AND METHODS: A prospective, multicenter, open-label clinical trial was initiated to evaluate the safety and performance of a novel miniaturized stimulator in the treatment of chronic, intractable leg and low-back pain. Eligible subjects were recruited for the study and gave consent. Subjects who passed the screening/trial phase (defined as ≥ 50% decrease in pain) continued to the long-term implant phase and were followed up at predefined time points after device activation. Interim clinical and usability outcomes were captured and reported at 90 days. RESULTS: Results of 22 subjects who chose a novel pulsed stimulation pattern therapy using the battery-free IPG (< 1.5 cm3) are described here. At 90-days follow-up, the average pain reduction was 79% in the leg (n = 22; p < 0.0001) and 76% in the low back (n = 21; p < 0.0001) compared with baseline. Responder rates (≥ 50% pain relief) at 90 days were 86% in leg pain (19/22) and 81% in low-back pain (17/21). Subjects rated the level of comfort of the external wearable power source to be 0.41 ± 0.73 at 90 days on an 11-point rating scale (0 = very comfortable, 10 = very uncomfortable). DISCUSSION: These interim results from the ongoing study indicate the favorable efficacy and usability of a novel, externally powered, battery-free SCS IPG (< 1.5 cm3) for leg and low-back pain. Study subjects wore the external power source continuously and found it comfortable, and the system provided significant pain relief. These preliminary findings warrant further investigation. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is ACTRN12618001862235.

A Novel Pulsed Stimulation Pattern in Spinal Cord Stimulation: Clinical Results and Postulated Mechanisms of Action in the Treatment of Chronic Low Back and Leg Pain.

OBJECTIVES: The aim of this article is to discuss the possible mechanisms of action (MOAs) and results of a pilot study of a novel, anatomically placed, and paresthesia-independent, neurostimulation waveform for the management of chronic intractable pain. MATERIALS AND METHODS: A novel, multilayered pulsed stimulation pattern (PSP) that comprises three temporal layers, a Pulse Pattern layer, Train layer, and Dosage layer, was developed for the treatment of chronic intractable pain. During preliminary development, the utility was evaluated of anatomical PSP (aPSP) in human subjects with chronic intractable pain of the leg(s) and/or low back, compared with that of traditional spinal cord stimulation (T-SCS) and physiological PSP. The scientific theory and testing presented in this article provide the preliminary justification for the potential MOAs by which PSP may operate. RESULTS: During the pilot study, aPSP (n = 31) yielded a greater decrease in both back and leg pain than did T-SCS (back: -60% vs -46%; legs: -63% vs -43%). In addition, aPSP yielded higher responder rates for both back and leg pain than did T-SCS (61% vs 48% and 78% vs 50%, respectively). DISCUSSION: The novel, multilayered approach of PSP may provide multimechanistic therapeutic relief through preferential fiber activation in the dorsal column, optimization of the neural onset response, and use of both the medial and lateral pathway through the thalamic nuclei. The results of the pilot study presented here suggest a robust responder rate, with several subjects (five subjects with back pain and three subjects with leg pain) achieving complete relief from PSP during the acute follow-up period. These clinical findings suggest PSP may provide a multimechanistic, anatomical, and clinically effective management for intractable chronic pain. Because of the limited sample size of clinical data, further testing and long-term clinical assessments are warranted to confirm these preliminary findings.

Trends in Haptic Communication of Human-Human Dyads: Toward Natural Human-Robot Co-manipulation.

In this paper, we analyze and report on observable trends in human-human dyads performing collaborative manipulation (co-manipulation) tasks with an extended object (object with significant length). We present a detailed analysis relating trends in interaction forces and torques with other metrics and propose that these trends could provide a way of improving communication and efficiency for human-robot dyads. We find that the motion of the co-manipulated object has a measurable oscillatory component. We confirm that haptic feedback alone represents a sufficient communication channel for co-manipulation tasks, however we find that the loss of visual and auditory channels has a significant effect on interaction torque and velocity. The main objective of this paper is to lay the essential groundwork in defining principles of co-manipulation between human dyads. We propose that these principles could enable effective and intuitive human-robot collaborative manipulation in future co-manipulation research.

Characteristics, Outcomes, and Trends of Patients With COVID-19-Related Critical Illness at a Learning Health System in the United States.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic continues to surge in the United States and globally. OBJECTIVE: To describe the epidemiology of COVID-19-related critical illness, including trends in outcomes and care delivery. DESIGN: Single-health system, multihospital retrospective cohort study. SETTING: 5 hospitals within the University of Pennsylvania Health System. PATIENTS: Adults with COVID-19-related critical illness who were admitted to an intensive care unit (ICU) with acute respiratory failure or shock during the initial surge of the pandemic. MEASUREMENTS: The primary exposure for outcomes and care delivery trend analyses was longitudinal time during the pandemic. The primary outcome was all-cause 28-day in-hospital mortality. Secondary outcomes were all-cause death at any time, receipt of mechanical ventilation (MV), and readmissions. RESULTS: Among 468 patients with COVID-19-related critical illness, 319 (68.2%) were treated with MV and 121 (25.9%) with vasopressors. Outcomes were notable for an all-cause 28-day in-hospital mortality rate of 29.9%, a median ICU stay of 8 days (interquartile range [IQR], 3 to 17 days), a median hospital stay of 13 days (IQR, 7 to 25 days), and an all-cause 30-day readmission rate (among nonhospice survivors) of 10.8%. Mortality decreased over time, from 43.5% (95% CI, 31.3% to 53.8%) to 19.2% (CI, 11.6% to 26.7%) between the first and last 15-day periods in the core adjusted model, whereas patient acuity and other factors did not change. LIMITATIONS: Single-health system study; use of, or highly dynamic trends in, other clinical interventions were not evaluated, nor were complications. CONCLUSION: Among patients with COVID-19-related critical illness admitted to ICUs of a learning health system in the United States, mortality seemed to decrease over time despite stable patient characteristics. Further studies are necessary to confirm this result and to investigate causal mechanisms. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality.

Retrospective Analysis of Real-World Outcomes of 10 kHz SCS in Patients with Upper Limb and Neck Pain.

BACKGROUND: Patients living with chronic upper limb and neck (ULN) pain are reliant on often ineffective therapies as they face limited options for effective long-term treatment. OBJECTIVE: Prospective clinical studies have demonstrated that high-frequency spinal cord stimulation at 10 kHz (10 kHz SCS) is effective in treating chronic pain in multiple etiologies including ULN pain. This study aimed at validating the findings from clinical studies on ULN in a real-world cohort. STUDY DESIGN: A retrospective, observational review. SETTING: A multicenter review between April 2016 and August 2019. PATIENTS AND METHODS: Anonymized data were extracted from a real-world database of 47 consecutive patients aged ≥18 years of age with chronic upper limb and/or neck pain who were trialed and permanently implanted with 10 kHz SCS. Patient-reported pain relief, quality of life, function, sleep and medication use were extracted from anonymised patient records where available. Responder rates, defined as the proportion of patients with at least 50% pain relief at the end of trial and the last visit after implantation, were calculated. RESULTS: All patients reported successful response (≥50% pain relief) at the end of trial and >75% patients continued to respond to the therapy at the last follow-up period. Majority (72%) of patients reported improvement in function, about half of the patients (53%) reported improvement in sleep and one-third of the patients (36%) reported reducing their medication at last follow-up. CONCLUSION: 10 kHz SCS provides durable pain relief to patients with chronic upper limb and neck pain.

10 kHz spinal cord stimulation for chronic upper limb and neck pain: Australian experience.

PURPOSE: Intractable upper limb and neck pain has traditionally been a challenging pain condition to treat, with conventional spinal cord stimulation (SCS) often inducing positional variation in paraesthesia and/or inadequate coverage of axial neck pain. The purpose of this Australian multi-centre prospective, clinical trial was to assess the safety and effectiveness of paraesthesia-independent 10 kHz SCS for the treatment of upper limb and neck pain. METHODS: Subjects with chronic, intractable neck and/or upper limb pain of ≥ 5 cm (on a 0-10-cm visual analogue scale) were enrolled (ACTRN12614000153617) following human research ethics committee approval. Subjects were implanted with two epidural leads spanning C2-C6 vertebral bodies. Subjects with successful trial stimulation were implanted with a Senza® system (Nevro Corp., Redwood City, CA, USA) and included in the safety and effectiveness evaluation at 3 months post-implant (primary endpoint assessment, PEA) and followed to 12 months. RESULTS: Overall, 31/38 (82.6%) subjects reported a successful 10 kHz SCS trial and proceeded to a permanent implant. Twenty-three of 30 subjects (76.7%) met the PEA. Subjects reported a reduction in neck pain and upper limb pain from baseline at the PEA (8.1 ± 0.2 cm vs. 2.9 ± 0.5 cm, 7.3 ± 0.3 cm vs. 2.5 ± 0.5 cm, respectively, p ≤ 0.0001). Disability, as measured by pain disability index score, decreased from 42.6 ± 2.6 at baseline to 22.7 ± 3.2 at PEA. Results were maintained 12 months post-implant. No neurological deficits, nor reports of paraesthesia, were observed. CONCLUSIONS: Stable, long-term results demonstrated that 10 kHz SCS is a promising therapy option for intractable chronic upper limb and neck pain.

High-frequency spinal cord stimulation at 10 kHz for widespread pain: a retrospective survey of outcomes from combined cervical and thoracic electrode placements.

OBJECTIVE: To report on the long-term outcomes for patients receiving paraesthesia-free high-frequency spinal cord stimulation (HF10-SCS) at 10 kHz for the treatment of combined upper and lower body neuropathic/nociplastic pain syndromes including chronic widespread pain/fibromyalgia. MATERIALS AND METHODS: Forty-five patients with widespread (both upper and lower body) neuropathic/nociplastic pain syndromes underwent a trial of combined cervical and thoracic HF10-SCS leads placed over the C2/T2 or C2/T9 vertebral levels, or three leads placed over the C2/T2/T9 vertebral levels. Thirty-eight patients proceeded to permanent implant, resulting in a trial to implant conversion rate of 84.4%. Patients were followed up an average of 2.3 ± 1.7 years post-permanent implant. Patient outcomes were recorded. RESULTS: A statistically significant reduction of 3.5 ± 1.6 on the 10-point numerical rating scale (NRS) at 2.3 ± 1.7 years post-permanent implant was observed (baseline: 7.1 ± 0.8 vs. follow up: 3.7 ± 1.3) (p ≤ 001). Likewise, a reduction in disability (Roland Morris Disability Questionnaire) was also observed; baseline: 12.3 ± 5.1 vs. follow up: 7.8 ± 5.9. Similar trends were observed in a working capacity, with 20/31 (64.5%) of the work eligible patients employed at follow-up, compared with only 8/31 (25.8%) at baseline. Opioid pain medication use reduced and over 90% of patients were satisfied with their treatment outcome. No long-term adverse events were observed. CONCLUSIONS: HF10-SCS at 10 kHz provides long-term widespread pain relief when leads are staggered across the cervical and thoracic spine. The improved return to work outcomes and opiate reductions suggest that cost-effectiveness as well as clinical effectiveness may be achieved with this treatment approach.

Microperimetry and optical coherence tomography imaging in the fellow eye of patients with unilateral focal ischaemic glaucoma.

PURPOSE: To determine whether microperimetry or optical coherence tomography (OCT) imaging can detect early disease in the fellow eye of patients with unilateral focal ischaemic glaucoma. METHODS: Thirty-seven consecutive adult patients with unilateral focal ischaemic glaucoma with a unilateral split-fixation visual field defect on standard automated perimetry (SAP) with normal SAP in the fellow eye were selected. All patients underwent microperimetry (MAIA, CenterVue, Italy) of the central 10 degrees and OCT imaging (Spectralis, Heidelberg Engineering, Germany) of the retinal nerve fibre layer of both eyes. The main outcome measures were reduced retinal sensitivity on microperimetry and/or retinal nerve fibre layer thinning on OCT imaging of the fellow eye. RESULTS: Thirty fellow eyes had abnormal global thresholds on microperimetry, and 20 had abnormal OCT imaging studies. Kappa agreement between tests in fellow eyes was poor (p = 0.2546). Fixation was significantly poorer in fellow eyes on microperimetry when compared to eyes with glaucoma (p < 0.003). In the fellow eyes that were abnormal, microperimetry identified reduced retinal sensitivity at fixation. CONCLUSION: Microperimetry detects reduced retinal sensitivity close to fixation and OCT detects focal thinning of the retinal nerve fibre layer in the fellow eye of most patients with presumed unilateral focal ischaemic glaucoma. Further studies are required to correlate specific optic disc features on OCT imaging with microperimetry in the fellow eye of this patient group.

The effect of trabeculectomy surgery on the central visual field in patients with glaucoma using microperimetry and optical coherence tomography.

PURPOSE: To determine the functional and structural effects of trabeculectomy surgery on patients with advanced glaucoma and central visual field defects in the early post-operative period. METHODS: Thirty consecutive adult subjects with advanced glaucoma requiring trabeculectomy surgery and an established visual field defect within 10° of fixation underwent microperimetry (MAIA MP-1, CenterVue, Padova, Italy) and optic disc optical coherence tomography (OCT) imaging (Spectralis, Heidelberg Engineering, Germany) pre-operatively, and 1 month and 3 months following trabeculectomy surgery. Main outcome measures were post-trabeculectomy change in mean threshold on microperimetry and nerve fibre layer thickness on OCT. Fellow eyes were used as controls. RESULTS: The mean change in MP average threshold values from pre-operative to post-operative was 0.6 ± 1.9 dB for treated eyes and 0.1 ± 1.3 dB for control eyes (p = 0.14) at 1 month and 0.2 ± 2.3 and -0.3 ± 1.6 dB at 3 months (p = 0.22). Mean change in global nerve fibre layer thickness was -0.6 and -0.5 µm for operated and control eyes, respectively (p = 0.83), at 1 month and 0.8 and -0.4 µm at 3 months (p = 0.88). The kappa agreement for structure-function correlation between OCT and MP was 0.735 (confidence interval 0.59-0.88) (p < 0.005). CONCLUSIONS: Central visual function and retinal nerve fibre layer thickness appear to be preserved in glaucoma patients with central visual field defects undergoing trabeculectomy surgery in the early post-operative period. These data may inform glaucoma surgeons considering trabeculectomy surgery in this patient group.

Effect of a punctal plug on ocular surface disease in patients using topical prostaglandin analogues: a randomized controlled trial.

IMPORTANCE: Ocular surface disease (OSD) is common and can reduce treatment compliance and quality of life. BACKGROUND: To determine whether a punctal plug improves OSD and reduces intraocular pressure (IOP) in patients using prostaglandin analogue monotherapy. DESIGN: Randomized controlled trial. PARTICIPANTS: Sixty eligible subjects aged >18 years with symptomatic OSD from glaucoma clinics were invited to participate. Lacrimal or glaucoma surgery, lid malposition and contact lens wear were exclusion criteria. METHODS: One eye received an inferior punctal plug, leaving the fellow eye as a control. MAIN OUTCOME MEASURES: Ocular surface disease index (OSDI), tear film breakup time (TF-BUT), Oxford cornea score, tear osmolarity and IOP were compared at baseline and 6 weeks by masked investigators. RESULTS: From 60 eligible, 48 (80.0%) participated (mean age 69.6 years; 60.0% female). OSDI reduced following plug insertion (mean difference [MD] 14.5, 95% confidence interval [CI] 5.06-23.94, P < 0.001). Compared to control eyes, in eyes receiving plugs the TF-BUT increased (MD 2.3 s, 95% CI 1.4-3.2, P < 0.001), the Oxford cornea score decreased (MD 0.5, 95% CI 0.3-0.7, P < 0.001), and tear osmolarity decreased (MD 10 mOsm/L, 95% CI 3.5-16.5, P = 0.003). Punctal plugs resulted in a significantly lowered IOP (MD 1.5 mmHg, 95% CI 0.1-2.9, P = 0.032). Sub-group analyses showed similar efficacy regardless of prostaglandin preservative status or lubricant drop use. Plugs were well tolerated but extrusion occurred in 8.5%, and epiphora increased in 6.5% eyes. CONCLUSIONS AND RELEVANCE: Punctal plug insertion improves subjective and objective measures of OSD and results in a reduced IOP in patients with symptomatic ocular surface disease using prostaglandin analogue monotherapy.

Twenty-year outcomes in patients with newly diagnosed glaucoma: mortality and visual function.

BACKGROUND/AIMS: To determine the mortality within 20 years of diagnosis of chronic open-angle glaucoma (COAG) and visual acuity and visual field progression of a cohort followed for 20 years. METHODS: Twenty years following the diagnosis of COAG in 68 of 436 (16%) patients seen in a glaucoma case-finding clinic, visual and mortality outcomes were audited from medical records. Causes of death were obtained from general practitioner records and death certificates. Probability of death was calculated using a Kaplan-Meier survival curve. The visual field of each eye of survivors was graded using a nine-stage severity scale. Visual outcome was analysed at the 20-year follow-up visit. RESULTS: From 68, 14 (21%) were lost to follow-up. In the remaining 54, 20 (37%) were alive 20 years after diagnosis. Of 63% who died, mean age of death was 84 years, most commonly due to vascular disease. Mean age at presentation of those who died was 73.7 years versus 63.2 years for survivors (P=0.001). The median time to death was 16 years. On visual field analysis, nearly half (48.9%) of eyes did not deteriorate, but 28.3% eyes deteriorated by more than two stages. Those who died had worse final visual acuity than survivors (P<0.001). Three who died were registered severely visually impaired mainly from macular disease, but no survivors were registered (P<0.001). CONCLUSION: In this cohort, approximately two-thirds of patients with glaucoma died within 20 years of diagnosis. In most older patients with glaucoma, the overall goal of preventing visual handicap and blindness is achievable 20 years after diagnosis.

The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (TABUL): a diagnostic accuracy and cost-effectiveness study.

BACKGROUND: Giant cell arteritis (GCA) is a relatively common form of primary systemic vasculitis, which, if left untreated, can lead to permanent sight loss. We compared ultrasound as an alternative diagnostic test with temporal artery biopsy, which may be negative in 9-61% of true cases. OBJECTIVE: To compare the clinical effectiveness and cost-effectiveness of ultrasound with biopsy in diagnosing patients with suspected GCA. DESIGN: Prospective multicentre cohort study. SETTING: Secondary care. PARTICIPANTS: A total of 381 patients referred with newly suspected GCA. MAIN OUTCOME MEASURES: Sensitivity, specificity and cost-effectiveness of ultrasound compared with biopsy or ultrasound combined with biopsy for diagnosing GCA and interobserver reliability in interpreting scan or biopsy findings. RESULTS: We developed and implemented an ultrasound training programme for diagnosing suspected GCA. We recruited 430 patients with suspected GCA. We analysed 381 patients who underwent both ultrasound and biopsy within 10 days of starting treatment for suspected GCA and who attended a follow-up assessment (median age 71.1 years; 72% female). The sensitivity of biopsy was 39% [95% confidence interval (CI) 33% to 46%], which was significantly lower than previously reported and inferior to ultrasound (54%, 95% CI 48% to 60%); the specificity of biopsy (100%, 95% CI 97% to 100%) was superior to ultrasound (81%, 95% CI 73% to 88%). If we scanned all suspected patients and performed biopsies only on negative cases, sensitivity increased to 65% and specificity was maintained at 81%, reducing the need for biopsies by 43%. Strategies combining clinical judgement (clinician's assessment at 2 weeks) with the tests showed sensitivity and specificity of 91% and 81%, respectively, for biopsy and 93% and 77%, respectively, for ultrasound; cost-effectiveness (incremental net monetary benefit) was £485 per patient in favour of ultrasound with both cost savings and a small health gain. Inter-rater analysis revealed moderate agreement among sonographers (intraclass correlation coefficient 0.61, 95% CI 0.48 to 0.75), similar to pathologists (0.62, 95% CI 0.49 to 0.76). LIMITATIONS: There is no independent gold standard diagnosis for GCA. The reference diagnosis used to determine accuracy was based on classification criteria for GCA that include clinical features at presentation and biopsy results. CONCLUSION: We have demonstrated the feasibility of providing training in ultrasound for the diagnosis of GCA. Our results indicate better sensitivity but poorer specificity of ultrasound compared with biopsy and suggest some scope for reducing the role of biopsy. The moderate interobserver agreement for both ultrasound and biopsy indicates scope for improving assessment and reporting of test results and challenges the assumption that a positive biopsy always represents GCA. FUTURE WORK: Further research should address the issue of an independent reference diagnosis, standards for interpreting and reporting test results and the evaluation of ultrasound training, and should also explore the acceptability of these new diagnostic strategies in GCA. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Juvenile-onset Normal Tension Glaucoma From Chronic, Recurrent Low Cerebrospinal Fluid Pressure.

INTRODUCTION: The evidence for low cerebrospinal fluid pressure (CSFP) as a key parameter in the pathogenesis of glaucoma is increasing. Primate models have demonstrated the onset normal tension glaucoma (NTG) from experimentally induced chronic intrathecal hypotension; an approach not possible in human subjects. CASE PRESENTATION: A 27-year-old man presented with a central scotoma in his left eye. He had undergone 8 CSF shunt revision procedures over a 25-year period secondary to recurrent low CSFP following surgical excision of a pinealoblastoma, aged 2. A focal nerve fiber layer defect was detected in the left eye associated with reduced retinal sensitivity on microperimetry. Three adjacent optic disc hemorrhages had been documented in the same position over an 18-month period. A diagnosis of left-sided NTG was made; the patient was started on Latanoprost 0.005%. A new generation CSF shunting device (ProGAV)-which neutralizes CSFP fluctuations analogously to trabeculectomy surgery for intraocular pressure-was considered necessary in this patient to alleviate persistent headaches and reduce the risk of progressive glaucomatous visual loss. CONCLUSIONS: This exceptional case illustrates how premature onset NTG may occur as a result of chronic, recurrent intrathecal hypotension-a "pure" human model. We describe an original management approach of implanting an adjustable, programmable CSF shunt valve (ProGAV) to reduce fluctuations in the translaminar cribrosa pressure difference, and reduce the risk of glaucomatous visual loss.

High Frequency Spinal Cord Stimulation at 10 kHz for the Treatment of Chronic Pain: 6-Month Australian Clinical Experience.

BACKGROUND: High frequency spinal cord stimulation at 10 kHz (HF10 therapy) represents a prominent advance in spinal cord stimulation (SCS) therapy, having demonstrated enhanced efficacy in patients with back and leg pain and pain relief without paresthesia that is sustained at 24 months post implant. OBJECTIVE: To report on the effectiveness HF10 SCS therapy for a wide range of intractable pain conditions in clinical practice. STUDY DESIGN: Retrospective investigation of 256 patients who trialed HF10 SCS for chronic intractable pain of various etiologies. SETTING: Three Australian pain clinics. METHODS: Two hundred fifty-six patients trialed HF10 SCS with view of a permanent implant if successful. Pain distributions included back + leg, back only, head ± neck, and neck ± arm/shoulder. About 30% of patients had previously failed traditional low-frequency paresthesia-based stimulation, while the remaining cohort were either highly refractory to treatment or not recommended by the pain physician for traditional SCS. Pain scores (numerical pain rating scale - NPRS) and functional outcome measures (Oswestry Disability Index - ODI; and activity tolerance times) were assessed at baseline, post-trial, and at 3 and 6 months post-implant as available in the medical records. RESULTS: Of the 256 patients, 189 (73%) reported a positive trial and were implanted. Patients with back + leg pain demonstrated the highest trial success rate (81%). A mean reduction in pain, among those for whom data were available, of 50% was sustained up to 6 months post-implant across the entire patient population. Sixty-eight percent of patients who failed traditional SCS reported a positive trial and mean pain relief at 6 months was 49% (P < 0.001). An 8.6 point reduction in ODI (21%) at 6 months and improved sitting, standing, and walking tolerances were also reported. LIMITATIONS: As data was collected retrospectively, missing data points were unavoidable; this was primarily due to inconsistent data collection and patients being lost to follow-up. Patient populations were diverse and a control group was not appropriate in this setting. CONCLUSIONS: These retrospective results demonstrate a significant advancement for patients suffering with chronic intractable pain and are consistent with recently published clinical results for HF10 SCS. HF10 SCS appears to be a viable, paresthesia-free alternative to traditional SCS, with high trial success rates, demonstrated effectiveness in a range of pain distributions including those typically difficult to treat with traditional SCS, and the possibility to restore pain control in patients who have previously failed traditional SCS. KEY WORDS: Spinal cord stimulation, high frequency stimulation, HF10, paresthesia-free stimulation, back pain, leg pain, cervical pain, neuromodulation.