Ink-based textile electrodes for wearable functional electrical stimulation: A proof-of-concept study to evaluate comfort and efficacy.

BACKGROUND: Functional Electrical Stimulation (FES) represents a promising technique for promoting functional recovery in individuals with neuromuscular diseases. Traditionally, current pulses are delivered through self-adhesive hydrogel Ag/AgCl electrodes, which allow a good contact with the skin, are easy-to-use and have a moderate cost. However, skin adherence decreases after a few uses and skin irritations can originate. Recently, textile electrodes have become an attractive alternative as they assure increased durability, easy integration into clothes and can be conveniently cleaned, improving the wearability of FES. However, as various manufacture processes were attempted, their clear validation is lacking. This proof-of-concept study proposes a novel set of ink-based printed textile electrodes and compares them to adhesive hydrogel electrodes in terms of impedance, stimulation performance and perceived comfort. METHODS: The skin-electrode impedance was evaluated for both types of electrodes under different conditions. These electrodes were then used to deliver FES to the Rectus Femoris of 14 healthy subjects to induce its contraction in both isometric and dynamic conditions. This allowed to compare the two types of electrodes in terms of sensory, motor, maximum and pain thresholds, FES-induced range of motion during dynamic tests, FES-induced torque during isometric tests and perceived stimulation comfort. RESULTS: No statistically significant differences were found both in terms of stimulation performance (Wilcoxon test) and comfort (Generalized Linear Mixed Model). CONCLUSION: The results showed that the proposed ink-based printed textile electrodes can be effectively used as alternative to hydrogel ones. Further experiments are needed to evaluate their durability and their response to sterilizability and stretching tests.

Effectiveness and safety of dolutegravir two-drug regimens in virologically suppressed people living with HIV: a systematic literature review and meta-analysis of real-world evidence.

OBJECTIVES: Dolutegravir (DTG) is widely recommended within three-drug regimens. However, similar efficacy and tolerability have also been achieved with DTG within two-drug regimens in clinical trials. This study evaluated the real-world effectiveness and discontinuations in people living with HIV-1 (PLHIV) switching to DTG with lamivudine (3TC) or rilpivirine (RPV). METHODS: This was a one-arm meta-analysis utilizing data from a systematic literature review. Data from real-world evidence studies of DTG + RPV and DTG + 3TC were extracted, pooled and analysed. The primary outcome was the proportion of patients with viral failure (VF; ≥ 50 copies/mL in two consecutive measurements and/or ≥ 1000 copies/mL in a single measurement) at week 48 (W48) and week 96 (W96). Other outcomes included virological suppression (VS; < 50 copies/mL) and discontinuations (W48 and W96). Estimates were calculated for VF, VS as per snapshot (VSS) and on treatment analysis (VSOT), and discontinuations. RESULTS: Pooled mean estimates of VF for DTG + 3TC and DTG + RPV were 0.8% [95% confidence interval (CI): 0.4-1.3] and 0.6% (95% CI: 0.0-1.6), respectively, at W48. VSS rate at W48 was 85.0% (95% CI: 82.3-87.5) for DTG + 3TC regimen and 92.4% (95% CI: 85.0-97.7) in the DTG + RPV regimen. The DTG + 3TC and DTG + RPV regimens led to discontinuations in 13.6% (95% CI: 11.1-16.2) and 7.2% (95% CI: 2.1-14.4) of patients, respectively, at W48. Similar results were observed at W96. CONCLUSIONS: Treatment with DTG + 3TC or DTG + RPV in clinical practice provides a low rate of VF and a high rate of VS when initiated in virologically suppressed PLHIV with diverse backgrounds.

Perinatal iron deficiency combined with a high salt diet in adulthood causes sex-dependent vascular dysfunction in rats.

KEY POINTS: Perinatal iron deficiency causes changes in offspring mesenteric artery function in adulthood, particularly in males, which can be exacerbated by chronic intake of a high salt diet. Perinatal iron deficient male offspring exhibit enhanced conversion of big endothelin-1 to active endothelin-1, coinciding with decreased nitric oxide levels. Perinatal iron deficient male offspring have reduced nitric oxide-mediated endothelial-dependent vasodilatation coincident with increased vascular superoxide levels following consumption of a high salt diet. Perinatal iron deficiency has no apparent effects on vascular function in female offspring, even when fed a high salt diet. These results help us better understand underlying vascular mechanisms contributing to increased cardiovascular risk from perinatal stressors such as iron deficiency. ABSTRACT: Pre- and immediate postnatal stressors, such as iron deficiency, can alter developmental trajectories and predispose offspring to long-term cardiovascular dysfunction. Here, we investigated the impact of perinatal iron deficiency on vascular function in the adult offspring, and whether these long-term effects were exacerbated by prolonged consumption of a high salt diet in adulthood. Female Sprague Dawley rats were fed either an iron-restricted or -replete diet prior to and throughout pregnancy. Six weeks prior to experimentation at 6 months of age, adult offspring were fed either a normal or high salt diet. Mesenteric artery responses to vasodilators and vasoconstrictors were assessed ex vivo by wire myography. Male perinatal iron deficient offspring exhibited decreased reliance on nitric oxide with methacholine-induced vasodilatation (interaction P = 0.03), coincident with increased superoxide levels when fed the high salt diet (P = 0.01). Male perinatal iron deficient offspring exhibit enhanced big endothelin-1 conversion to active endothelin-1 (P = 0.02) concomitant with decreased nitric oxide levels (P = 0.005). Female offspring vascular function was unaffected by perinatal iron deficiency, albeit the high salt diet was associated with impaired vasodilation and decreased nitric oxide production (P = 0.02), particularly in the perinatal iron deficient offspring. These findings implicate vascular dysfunction in the sex-specific programming of cardiovascular dysfunction in the offspring by perinatal iron deficiency.

Prenatal iron deficiency causes sex-dependent mitochondrial dysfunction and oxidative stress in fetal rat kidneys and liver.

Prenatal iron deficiency alters fetal developmental trajectories, which results in persistent changes in organ function. Here, we studied the effects of prenatal iron deficiency on fetal kidney and liver mitochondrial function. Pregnant Sprague-Dawley rats were fed partially or fully iron-restricted diets to induce a state of moderate or severe iron deficiency alongside iron-replete control rats. We assessed mitochondrial function via high-resolution respirometry and reactive oxygen species generation via fluorescence microscopy on gestational d 21. Hemoglobin levels were reduced in dams in the moderate (-31%) and severe groups (-54%) compared with controls, which was accompanied by 55% reductions in fetal hemoglobin levels in both moderate and severe groups versus controls. Male iron-deficient kidneys exhibited globally reduced mitochondrial content and respiration, as well as increased cytosolic superoxide and decreased NO. Female iron-deficient kidneys exhibited complex II down-regulation and increased mitochondrial oxidative stress. Male iron-deficient livers exhibited reduced complex IV respiration and increased cytosolic superoxide, whereas female liver tissues exhibited no alteration in oxidant levels or mitochondrial function. These findings indicate that prenatal iron deficiency causes changes in mitochondrial content and function as well as oxidant status in a sex- and organ-dependent manner, which may be an important mechanism that underlies the programming of cardiovascular disease.-Woodman, A. G., Mah, R., Keddie, D., Noble, R. M. N., Panahi, S., Gragasin, F. S., Lemieux, H., Bourque, S. L. Prenatal iron deficiency causes sex-dependent mitochondrial dysfunction and oxidative stress in fetal rat kidneys and liver.

Survival of Staphylococcus epidermidis in Propofol and Intralipid in the Dead Space of Intravenous Injection Ports.

We tested whether propofol or Intralipid inoculated with Staphylococcus epidermidis would promote bacterial growth within an intravenous (IV) injection hub, a site prone to bacterial contamination. In tubes incubated under optimal conditions, S epidermidis exhibited growth in Intralipid, but not in propofol. In contrast, within the IV hub incubated with either propofol or intralipid at room temperature, S epidermidis bacterial numbers declined with time, and virtually no contamination remained after 12 hours. These data suggest that certain IV lines are inhospitable for S epidermidis.

Assessing the accuracy of algorithm-derived cardiorespiratory fitness in surgical patients: a prospective cohort study.

PURPOSE: To determine if a non-exercise algorithm-derived assessment of cardiorespiratory fitness (CRFA) accurately predicted estimated values obtained using a six-minute walk test (CRF6MWD) and the Duke Activity Status Index (CRFDASI). METHODS: Following research ethics board approval, an observational cohort study was conducted in selected, consenting patients undergoing elective surgery. Participants completed questionnaires assessing their self-reported exercise capacity. Their height, weight, waist circumference, and vital signs were measured. A six-minute walk test was performed twice with a 45-min rest interval between tests. The correlation between CRFA and both CRF6MWD and CRFDASI was determined. RESULTS: Two hundred forty-two participants were included. Mean age was 62 (range 45-88 yr); 150 (62%) were male, 87 (36%) self-reported walking or jogging > 16 km per week, and 49 (20%) were current smokers. The CRFA and CRF6MWD were highly correlated (Pearson r = 0.878; P < 0.001). CRFA and CRFDASI were less strongly correlated (Pearson r = 0.252; P < 0.001). Among patients capable of walking > 427 m in the six-minute walk test, CRFA, CRF6MWD, and CRFDASI were equivalent. CONCLUSION: A non-exercise algorithm can estimate cardiorespiratory fitness in patients presenting for elective surgery. The variables required to compute CRFA can be obtained in a clinic setting without the need to engage in formal exercise testing. Further evaluation of CRFA as a predictor of long-term outcome in patients is warranted.

Propofol increases vascular relaxation in aging rats chronically treated with the angiotensin-converting enzyme inhibitor captopril.

BACKGROUND: Both propofol use and advanced age are predictors of intraoperative hypotension. We previously demonstrated that propofol enhances vasodilation in mesenteric arteries from aged rats, partly due to increased nitric oxide (NO) bioavailability. Patients chronically treated with angiotensin-converting enzyme (ACE) inhibitors may exhibit refractory hypotension under general anesthesia. We hypothesized that propofol enhances NO-mediated vasodilation in arteries from aged rats chronically treated with ACE inhibitors. METHODS: Sprague-Dawley rats aged 12 to 13 months were treated with or without captopril for 7 to 8 weeks, yielding a final age of 14 to 15 months at the time of experimentation. Before euthanasia, arterial blood pressures were obtained through carotid artery cannulation. Concentration-response curves to propofol (0.1-100 µM) or methacholine (MCh) (0.01-3 µM) were then assessed on isolated resistance mesenteric arteries (100-200 µm diameter) from both treatment (captopril) and control rats. MCh relaxation was also assessed after propofol pretreatment (1 and 10 µM). N(G)-nitro-l-arginine methyl ester (l-NAME) (100 µM) and meclofenamate (10 µM) were used to inhibit NO and prostaglandin synthesis, respectively. Concentration-response data were summarized as 50% of the maximum relaxation response or area under the curve. RESULTS: Mean arterial blood pressure in the captopril-treated rats was lower than in untreated rats (P = 0.049). When comparing relaxation in arteries from captopril-treated versus untreated rats, concentration-response curves revealed that captopril-treated rats display greater direct propofol relaxation (P = 0.018). MCh relaxation in the absence of propofol, however, was not different between captopril-treated and untreated rats (P = 0.80). Propofol pretreatment increased MCh relaxation in arteries from captopril-treated compared with untreated rats (P = 0.029 for 1 µM and P = 0.020 for 10 µM). Meclofenamate did not have an effect in this response (P = 0.22). l-NAME-dependent inhibition of MCh relaxation, however, was greater in arteries from control compared with captopril-treated rats (P = 0.0077). However, propofol increased the proportion of NO-dependent vasodilation to MCh similarly in both groups. This suggests that other vasodilatory pathways are involved in the differential response to MCh in the presence of propofol in captopril-treated rats. CONCLUSIONS: Our results show that mesenteric arterial relaxation in response to propofol, both by direct stimulation and through modulation of endothelium-dependent mechanisms, is, in part, NO-dependent. In captopril-treated rats, propofol further increased arterial relaxation through a non-NO-dependent vasodilating pathway (e.g., endothelium-derived hyperpolarizing factor), which may account for enhanced vasodilation during propofol exposure in patients treated with ACE inhibitors.

Successful Ultrasound-Guided Spinal Anesthesia in a Patient With Severe Hemophilia A Undergoing Total Hip Arthroplasty.

Neuraxial anesthesia is the preferred technique for total joint arthroplasties. However, the absolute safety of neuraxial anesthesia in hemophilia patients has not been established. We describe a case of an adult male with severe hemophilia A, who presented for primary hip replacement due to severe hemophilic arthropathy and was managed with ultrasound-facilitated neuraxial anesthesia. Due to bleeding risks, additional considerations were necessary to minimize development of postoperative spinal hematoma. There were no perioperative adverse events. Careful preoperative multidisciplinary planning, perioperative management of neuraxial anesthesia (including the use of spinal ultrasound), and hemostasis were instrumental to successfully accomplish this. Following these principles, we demonstrate that neuraxial techniques may be a safe option for managing patients with severe hemophilia A.

Development of the Italian version of the knee injury and osteoarthritis outcome score for patients with knee injuries: cross-cultural adaptation, dimensionality, reliability, and validity.

OBJECTIVE: Translating, culturally adapting and validating an Italian version of the Knee injury and Osteoarthritis Outcome Score (KOOS-I) to allow its use with Italian-speaking patients with knee complaints. DESIGN: The KOOS-I was developed by means of forward-backward translation, a final review by an expert committee, and a test of the pre-final version to establish its correspondence with the original English version. The psychometric testing included analysis of dimensionality using item-scale correlation after correction for overlap, reliability by means of internal consistency (Cronbach's alpha) and test-retest reliability (Intraclass Correlation Coefficients), and construct validity using an a priori hypothesised Pearson correlations with a Numerical Rating Scale (NRS) and the Short-Form 36 Health Survey (SF-36). RESULTS: The questionnaire was administered to 224 subjects with knee injuries and proved to be acceptable. Hypothesised item-to-domain correlations were observed for all of the items. The questionnaire showed good internal consistency (0.782-0.977), and a high level of test-retest reliability (0.850-0.949). Construct validity was supported by the confirmation of the a priori hypothesised correlations. CONCLUSIONS: The KOOS outcome measure was successfully translated into Italian, and proved to have good psychometric properties that replicated the results of existing versions. Its use is recommended for clinical and research purposes in patients with knee injuries.

Characterization of Systemic and Regional Hemodynamics and Vascular Dysfunction in Mice with Fecal Induced Peritonitis.

Sepsis is associated with circulatory dysfunction contributing to disturbed blood flow and organ injury. Decreased organ perfusion in sepsis is attributed, in part, to the loss of vasoregulatory mechanisms. Identifying which vascular beds are most susceptible to dysfunction is important for monitoring the recovery of organ function and guiding interventions. This study aimed to investigate the development of vascular dysfunction as sepsis progressed to septic shock. Anesthetized C57Bl/6 mice were instrumented with a fiberoptic pressure sensor in the carotid artery for blood pressure measurements. In subgroups of mice, regional blood flow measurements were taken by positioning a perivascular flow probe around either the left carotid, left renal, or superior mesenteric arteries. Hemodynamic parameters and their responsiveness to bolus doses of vasoactive drugs were recorded prior to and continuously after injection of fecal slurry (1.3 mg/g body weight) for 4 h. Fecal slurry-induced peritonitis reduced mean arterial pressure (62.7 ± 2.4 mmHg vs. 37.5 ± 3.2 mmHg in vehicle and septic mice, respectively), impaired cardiac function, and eventually reduced organ blood flow (71.9%, 66.8%, and 65.1% in the superior mesenteric, renal, and carotid arteries, respectively). The mesenteric vasculature exhibited dysregulation before the renal and carotid arteries, and this underlying dysfunction preceded the blood pressure decline and impaired organ blood flow.

Low-dose ketamine does not improve the speed of recovery from depression in electroconvulsive therapy: a randomized controlled trial.

OBJECTIVE: Electroconvulsive therapy (ECT) is a well-established therapeutic intervention for major depressive disorder. Recent literature has shown that the anesthetic agent ketamine has some antidepressant properties at low doses and may be an alternative therapy for treatment-resistant major depressive disorder. We hypothesized that the use of low-dose ketamine as an anesthetic adjunct in ECT would more rapidly improve depression while maintaining hemodynamic stability than ECT with propofol alone. METHODS: Institutional ethics approval was obtained, and the use of ketamine in this study was approved by Health Canada. This is a randomized, double-blinded, placebo-controlled trial that involved ketamine administration at 0.5 mg/kg IV in addition to propofol anesthesia for ECT. The primary outcome was the number of ECT treatments required to achieve a 50% reduction in the Montgomery-Asberg Depression Rating Scale (MADRS). Secondary outcomes included the number of ECT treatments required to achieve a 25% reduction in MADRS score, as well as any differences in the Clinical Global Impression Scale for Severity, hemodynamic variables, and seizure duration. Adverse events were recorded for safety assessment. RESULTS: A total of 45 patients completed the study. No difference was found between groups with respect to the primary or secondary outcomes. The ketamine group showed a trend towards a decreased dose of propofol required to achieve adequate anesthesia. No adverse events were reported. CONCLUSION: Low-dose ketamine does not improve psychiatric outcomes in the setting of propofol-based anesthesia for ECT. Specifically, ketamine did not reduce the number of ECT sessions necessary to achieve a 50 or 25% reduction in MADRS scores. Reassuringly, the fact that no differences in hemodynamic variables or unexpected adverse events occurred suggests that low-dose ketamine may be safely used in this setting should clinical indications warrant its use. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02579642.

A smart ink pen for spiral drawing analysis in patients with Parkinson's disease.

Handwriting skills could be highly impaired in patients affected by Parkinson's disease (PD), and for this reason its analysis had always been considered relevant. In handwriting assessment, Archimedes spiral drawing is one of the most proposed tasks, due to its peculiar shape and ease of execution. In the last decades, digitizing tablets had been widely employed for the evaluation of the spiral performance, providing a cheap and non-invasive way to gather quantitative information, to be combined with the classical clinical examination. Despite this advantage, such approach cannot easily be adopted in an unsupervised scenario and lacks the natural feel of the traditional pen-and-paper approach. This work aims at overcoming these limitations by employing a smart ink pen, designed to write on paper and instrumented with inertial and force sensors, to automatically collect data related to spiral drawing execution of PD patients (n=30) and age-matched healthy controls (n=30). From the raw data, several time and frequency domains features were extracted and compared between the groups. The statistical analysis revealed some significant differences, showing less smooth acceleration and force profiles for PD patients. However, given the heterogeneous symptoms presented by the PD cohort, a detailed analysis of exemplifying PD patients was conducted, showing the ability of Archimedes spiral drawing to capture and quantify PD characteristic features.Clinical Relevance- Among the first clinical manifestations of the pathology, handwriting impairment appears in PD patients. It is often underestimated and not investigated properly. This easy-to-use tool could be very useful as a large-scale screening, but also for treatment efficacy evaluation and for the identification of PD subgroups.

Maternal and Cord Blood Hemoglobin as Determinants of Placental Weight: A Cross-Sectional Study.

BACKGROUND: Both high and low placental weights are associated with adverse pregnancy outcomes. Maternal hemoglobin levels can influence placental weight, but the evidence is conflicting. Since maternal hemoglobin does not invariably correlate with fetal/neonatal blood hemoglobin levels, we sought to determine whether cord blood hemoglobin or maternal hemoglobin status more closely associates with placental weight in women undergoing elective cesarean section at term. METHODS: This was a cross-sectional study conducted at the Royal Alexandra Hospital, Edmonton, Canada, involving 202 women with term singleton pregnancies undergoing elective cesarean section. Maternal blood and mixed cord blood hemoglobin levels were analyzed using a HemoCue Hb201+ system. Birth weight, placental weight, one- and five-minute APGAR scores, American Society of Anesthesiologists physical state classification, maternal age, and maternal height were also recorded. Relationships between maternal and cord blood hemoglobin levels with placental weight, birth weight, and birth weight to placental weight ratio were the main outcome measures. RESULTS: A total of 182 subjects were included in the analysis. Regression analysis showed that cord blood hemoglobin, but not maternal hemoglobin, was inversely related with placental weight (ß = -2.4, p = 0.001) and positively related with the birth weight to placental weight ratio (ß = 0.015, p = 0.001 and p = 0.63, respectively). CONCLUSIONS: Our findings suggest that measuring cord blood hemoglobin levels, rather than maternal hemoglobin levels, may provide important diagnostic information about in utero fetal adaptation to suboptimal placental function and neonatal health.

Perinatal iron deficiency and a high salt diet cause long-term kidney mitochondrial dysfunction and oxidative stress.

AIMS: Perinatal iron deficiency (ID) alters developmental trajectories of offspring, predisposing them to cardiovascular dysfunction in later life. The mechanisms underlying this long-term programming of renal function have not been defined. We hypothesized perinatal ID causes hypertension and alters kidney metabolic function and morphology in a sex-dependent manner in adult offspring. Furthermore, we hypothesized these effects are exacerbated by chronic consumption of a high salt diet. METHODS AND RESULTS: Pregnant Sprague Dawley rats were fed either an iron-restricted or replete diet prior to and throughout pregnancy. Adult offspring were fed normal or high salt diets for 6 weeks prior to experimentation at 6 months of age. Blood pressure (BP) was assessed via indwelling catheters in anaesthetized offspring; kidney mitochondrial function was assessed via high-resolution respirometry; reactive oxygen species and nitric oxide were quantified via fluorescence microscopy. Adult males, but not females, exhibited increased systolic BP due to ID (P = 0.01) and high salt intake (P = 0.02). In males, but not in females, medullary mitochondrial content was increased by high salt (P = 0.003), while succinate-dependent respiration was reduced by ID (P < 0.05). The combination of perinatal ID and high salt reduced complex IV activity in the cortex of males (P = 0.01). Perinatal ID increased cytosolic superoxide generation (P < 0.001) concomitant with reduced nitric oxide bioavailability (P < 0.001) in male offspring, while high salt increased mitochondrial superoxide in the medulla (P = 0.04) and cytosolic superoxide within the cortex (P = 0.01). Male offspring exhibited glomerular basement membrane thickening (P < 0.05), increased collagen deposition (P < 0.05), and glomerular hypertrophy (interaction, P = 0.02) due to both perinatal ID and high salt. Female offspring exhibited no alterations in mitochondrial function or morphology due to either high salt or ID. CONCLUSION: Perinatal ID causes long-term sex-dependent alterations in renal metabolic function and morphology, potentially contributing to hypertension and increased cardiovascular disease risk.

The effects of propofol on vascular function in mesenteric arteries of the aging rat.

Hypotension following administration of propofol, an anesthetic agent, is strongly predicted by advanced age and is partly due to direct vasodilation. We hypothesized that propofol increases nitric oxide (NO)-mediated vasodilation by enhancing its bioavailability in the aged adult vasculature, leading to greater vasodilation than in the young adult. Small mesenteric arteries from rats aged 13-15 versus 3 to 4 mo were compared in this study. Reactivity to propofol (1-100 microM) alone and with the addition of acetylcholine (ACh; 0.1-10 microM) in endothelial-intact and dunuded arteries following phenylephrine constriction was assessed using myography. N(G)-nitro-L-arginine methyl ester (L-NAME) and meclofenamate (Meclo) were used to inhibit NO and prostaglandin synthesis, respectively. Superoxide dismutase (SOD) and catalase were used as antioxidants during ACh relaxation and were compared with propofol in aging arteries. Propofol alone induced greater relaxation in 1) endothelial-intact compared with denuded arteries and 2) aged compared with young arteries, which were inhibited by L-NAME. ACh-induced relaxation was greater in young compared with aged control arteries; however, propofol pretreatment increased this relaxation in aged but not in young arteries. Additionally, propofol inhibited ACh-induced relaxation in arteries treated with L-NAME + Meclo [relaxation attributed to endothelium-derived hyperpolarizing factor (EDHF)]. Pretreatment with SOD and catalase increased relaxation to ACh in aged arteries similar to propofol. In conclusion, propofol causes relaxation in small mesenteric arteries in an endothelial-dependent and independent manner and increases ACh-induced relaxation in aged arteries. Interestingly, propofol inhibits EDHF-mediated relaxation but increases availability of NO, which leads to overall vascular relaxation.

Automatic speech analysis to early detect functional cognitive decline in elderly population.

This study aimed at evaluating whether people with a normal cognitive function can be discriminated from subjects with a mild impairment of cognitive function based on a set of acoustic features derived from spontaneous speech. Voice recordings from 90 Italian subjects (age >65 years; group 1: 47 subjects with MMSE>26; group 2: 43 subjects with 20≤ MMSE ≤26) were collected. Voice samples were processed using a MATLAB-based custom software to derive a broad set of known acoustic features. Linear mixed model analyses were performed to select the features able to significantly distinguish between groups. The selected features (% of unvoiced segments, duration of unvoiced segments, % of voice breaks, speech rate, and duration of syllables), alone or in addition to age and years of education, were used to build a learning-based classifier. The leave-one-out cross validation was used for testing and the classifier accuracy was computed. When the voice features were used alone, an overall classification accuracy of 0.73 was achieved. When age and years of education were additionally used, the overall accuracy increased up to 0.80. These performances were lower than the accuracy of 0.86 found in a recent study. However, in that study the classification was based on several tasks, including more cognitive demanding tasks. Our results are encouraging because acoustic features, derived for the first time only from an ecologic continuous speech task, were able to discriminate people with a normal cognitive function from people with a mild cognitive decline. This study poses the basis for the development of a mobile application performing automatic voice analysis on-the-fly during phone calls, which might potentially support the detection of early signs of functional cognitive decline.

Effect of anesthesia on motor responses evoked by spinal neural prostheses during intraoperative procedures.

OBJECTIVE: The overall goal of this study was to investigate the effects of various anesthetic protocols on the intraoperative responses to intraspinal microstimulation (ISMS). ISMS is a neuroprosthetic approach that targets the motor networks in the ventral horns of the spinal cord to restore function after spinal cord injury. In preclinical studies, ISMS in the lumbosacral enlargement produced standing and walking by activating networks controlling the hindlimb muscles. ISMS implants are placed surgically under anesthesia, and refinements in placement are made based on the evoked responses. Anesthesia can have a significant effect on the responses evoked by spinal neuroprostheses; therefore, in preparation for clinical testing of ISMS, we compared the evoked responses under a common clinical neurosurgical anesthetic protocol with those evoked under protocols commonly used in preclinical studies. APPROACH: Experiments were conducted in seven pigs. An ISMS microelectrode array was implanted in the lumbar enlargement and responses to ISMS were measured under three anesthetic protocols: (1) isoflurane, an agent used pre-clinically and clinically, (2) total intravenous anesthesia (TIVA) with propofol as the main agent commonly used in clinical neurosurgical procedures, (3) TIVA with sodium pentobarbital, an anesthetic agent used mostly preclinically. Responses to ISMS were evaluated based on stimulation thresholds, movement kinematics, and joint torques. Motor evoked potentials (MEP) and plasma concentrations of propofol were also measured. MAIN RESULTS: ISMS under propofol anesthesia produced large and functional responses that were not statistically different from those produced under pentobarbital anesthesia. Isoflurane, however, significantly suppressed the ISMS-evoked responses. SIGNIFICANCE: This study demonstrated that the choice of anesthesia is critical for intraoperative assessments of motor responses evoked by spinal neuroprostheses. Propofol and pentobarbital anesthesia did not overly suppress the effects of ISMS; therefore, propofol is expected to be a suitable anesthetic agent for clinical intraoperative testing of an intraspinal neuroprosthetic system.