SocialBit: protocol for a prospective observational study to validate a wearable social sensor for stroke survivors with diverse neurological abilities.

INTRODUCTION: Social isolation has been found to be a significant risk factor for health outcomes, on par with traditional risk factors. This isolation is characterised by reduced social interactions, which can be detected acoustically. To accomplish this, we created a machine learning algorithm called SocialBit. SocialBit runs on a smartwatch and detects minutes of social interaction based on vocal features from ambient audio samples without natural language processing. METHODS AND ANALYSIS: In this study, we aim to validate the accuracy of SocialBit in stroke survivors with varying speech, cognitive and physical deficits. Training and testing on persons with diverse neurological abilities allows SocialBit to be a universally accessible social sensor. We are recruiting 200 patients and following them for up to 8 days during hospitalisation and rehabilitation, while they wear a SocialBit-equipped smartwatch and engage in naturalistic daily interactions. Human observers tally the interactions via a video livestream (ground truth) to analyse the performance of SocialBit against it. We also examine the association of social interaction time with stroke characteristics and outcomes. If successful, SocialBit would be the first social sensor available on commercial devices for persons with diverse abilities. ETHICS AND DISSEMINATION: This study has received ethical approval from the Institutional Review Board of Mass General Brigham (Protocol #2020P003739). The results of this study will be published in a peer-reviewed journal.

A machine learning eye movement detection algorithm using electrooculography.

STUDY OBJECTIVES: Eye movement quantification in polysomnograms (PSG) is difficult and resource intensive. Automated eye movement detection would enable further study of eye movement patterns in normal and abnormal sleep, which could be clinically diagnostic of neurologic disorders, or used to monitor potential treatments. We trained a long short-term memory (LSTM) algorithm that can identify eye movement occurrence with high sensitivity and specificity. METHODS: We conducted a retrospective, single-center study using one-hour PSG samples from 47 patients 18-90 years of age. Team members manually identified and trained an LSTM algorithm to detect eye movement presence, direction, and speed. We performed a 5-fold cross validation and implemented a "fuzzy" evaluation method to account for misclassification in the preceding and subsequent 1-second of gold standard manually labeled eye movements. We assessed G-means, discrimination, sensitivity, and specificity. RESULTS: Overall, eye movements occurred in 9.4% of the analyzed EOG recording time from 47 patients. Eye movements were present 3.2% of N2 (lighter stages of sleep) time, 2.9% of N3 (deep sleep), and 19.8% of REM sleep. Our LSTM model had average sensitivity of 0.88 and specificity of 0.89 in 5-fold cross validation, which improved to 0.93 and 0.92 respectively using the fuzzy evaluation scheme. CONCLUSION: An automated algorithm can detect eye movements from EOG with excellent sensitivity and specificity. Noninvasive, automated eye movement detection has several potential clinical implications in improving sleep study stage classification and establishing normal eye movement distributions in healthy and unhealthy sleep, and in patients with and without brain injury.

Ultrasound-guided peripheral intravenous access in chronic kidney disease patients.

OBJECTIVE: Ultrasound-guided peripheral intravenous (USPIV) catheters are being placed in emergency department (ED) patients with increasing frequency. USPIV catheters have been shown to improve the success rates of cannulation. It is unknown what the long-term effect of USPIV placement will be on fistula creation in chronic kidney disease (CKD) patients considering these ultrasound-guided peripheral lines often target the same deeper vessels used for fistulas. This study aimed to survey whether emergency medicine programs place restrictions on USPIV placement in patients with CKD stages 3-5. METHODS: This was a survey study encompassing all 110 emergency ultrasound fellowship directors in the United States at the time the survey was conducted. Data was collected on an anonymous and voluntary basis. The primary outcome was the number of programs with restrictions on USPIV placement in patients with CKD stage 3 or greater. RESULTS: Of the 56 programs that responded, 21% reported having policies limiting which patients were appropriate for USPIV. Despite this, only one program reported placing restrictions on USPIV in CKD stage 3 or greater (p < 0.0001). CONCLUSIONS: Emergency departments do not have or follow restrictions placed on USPIV placement in patients with CKD stage 3 or greater. The use of these veins in the ED may result in thrombosis as well as inflammation and permanent scarring which could negatively impact the ability to utilize those vessels for fistula creation. Future studies are needed to further characterize the impact of USPIV on fistula creation.

Cognitive impairment in a rat model of neuropathic pain: role of hippocampal microtubule stability.

Clinical evidence indicates that cognitive impairment is a common comorbid condition of chronic pain. However, the cellular basis for chronic pain-mediated cognitive impairment remains unclear. We report here that rats exhibited memory deficits after spared nerve injury (SNI). We found that levels of stable microtubule (MT) were increased in the hippocampus of the rats with memory deficits. This increase in stable MT is marked by α-tubulin hyperacetylation. Paclitaxel, a pharmacological MT stabilizer, increased the level of stable MT in the hippocampus and induced learning and memory deficits in normal rats. Furthermore, paclitaxel reduced long-term potentiation in hippocampal slices and increased stable MT (evidenced by α-tubulin hyperacetylation) levels in hippocampal neuronal cells. Intracerebroventricular infusion of nocodazole, an MT destabilizer, ameliorated memory deficits in rats with SNI-induced nociceptive behavior. Expression of HDAC6, an α-tubulin deacetylase, was reduced in the hippocampus in rats with cognitive impairment. These findings indicate that peripheral nerve injury (eg, SNI) affects the MT dynamic equilibrium, which is critical to neuronal structure and synaptic plasticity.

Gut microbiota is critical for the induction of chemotherapy-induced pain.

Chemotherapy-induced pain is a dose-limiting condition that affects 30% of patients undergoing chemotherapy. We found that gut microbiota promotes the development of chemotherapy-induced mechanical hyperalgesia. Oxaliplatin-induced mechanical hyperalgesia was reduced in germ-free mice and in mice pretreated with antibiotics. Restoring the microbiota of germ-free mice abrogated this protection. These effects appear to be mediated, in part, by TLR4 expressed on hematopoietic cells, including macrophages.

Marked elevation of B-type natriuretic peptide in patients with heart failure and preserved ejection fraction.

UNLABELLED: Marked elevations of B-type natriuretic peptide (BNP) are not generally seen in patients with heart failure and preserved ejection fraction (HFpEF). The objective of this study was to examine the clinical and laboratory characteristics of a large cohort of patients with HFpEF and markedly elevated BNP. A retrospective examination of 421 inpatients at a university hospital admitted with a diagnosis of HFpEF was performed. Clinical and echocardiographic data in 4 groups of patients with levels of BNP ≤ 100 pg/mL, 100-400 pg/mL, 400-1,000 pg/mL and > 1,000 pg/mL were compared. Patients with HFpEF and BNP > 1,000 pg/mL (28% of the population) were characterized by impaired renal function and greater use of anti-hypertensive medications. A subset of these patients with BNP > 1,000 pg/mL had normal renal function (21%) and were significantly older, more frequently female, and tended to have lower ejection fractions. Conversely, patients with HFpEF and BNP ≤ 100 pg/mL were younger and had preserved renal function. BNP was inversely related to the likelihood of subsequent admission for heart failure, but not to myocardial infarction or death. IN CONCLUSION: BNP > 1,000 pg/mL is seen in almost 1/3 of patients hospitalized with HFpEF. This elevation of BNP often reflects impaired renal function, but can also be seen in patients with preserved renal function but relatively impaired systolic function.