Multisite thalamic recordings to characterize seizure propagation in the human brain.

Neuromodulation of the anterior nuclei of the thalamus (ANT) has shown to be efficacious in a subset of patients with refractory focal epilepsy. One important uncertainty is to what extent thalamic subregions other than the ANT could be recruited more prominently in the propagation of focal onset seizures. We designed the current study to simultaneously monitor the engagement of the ANT, mediodorsal (MD) and pulvinar (PUL) nuclei during seizures in patients who could be candidates for thalamic neuromodulation. We studied 11 patients with clinical manifestations of presumed temporal lobe epilepsy (TLE) undergoing invasive stereo-encephalography (sEEG) monitoring to confirm the source of their seizures. We extended cortical electrodes to reach the ANT, MD and PUL nuclei of the thalamus. More than one thalamic subdivision was simultaneously interrogated in nine patients. We recorded seizures with implanted electrodes across various regions of the brain and documented seizure onset zones (SOZ) in each recorded seizure. We visually identified the first thalamic subregion to be involved in seizure propagation. Additionally, in eight patients, we applied repeated single pulse electrical stimulation in each SOZ and recorded the time and prominence of evoked responses across the implanted thalamic regions. Our approach for multisite thalamic sampling was safe and caused no adverse events. Intracranial EEG recordings confirmed SOZ in medial temporal lobe, insula, orbitofrontal and temporal neocortical sites, highlighting the importance of invasive monitoring for accurate localization of SOZs. In all patients, seizures with the same propagation network and originating from the same SOZ involved the same thalamic subregion, with a stereotyped thalamic EEG signature. Qualitative visual reviews of ictal EEGs were largely consistent with the quantitative analysis of the corticothalamic evoked potentials, and both documented that thalamic nuclei other than ANT could have the earliest participation in seizure propagation. Specifically, pulvinar nuclei were involved earlier and more prominently than ANT in more than half of the patients. However, which specific thalamic subregion first demonstrated ictal activity could not be reliably predicted based on clinical semiology or lobar localization of SOZs. Our findings document the feasibility and safety of bilateral multisite sampling from the human thalamus. This may allow more personalized thalamic targets to be identified for neuromodulation. Future studies are needed to determine if a personalized thalamic neuromodulation leads to greater improvements in clinical outcome.

Improving quality of antenatal care services in a high case load tertiary care teaching hospital (Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College) in Kanpur, Uttar Pradesh, India.

In India, half of all pregnant women between the ages of 15 and 49 years are anaemic. In Uttar Pradesh (UP), this figure is slightly higher at 51%. Unfortunately, only 5.4% pregnant women received full antenatal care (ANC) (National Family Health Survey 4, 2015-2016). A formative research conducted in UP in 2016 found that only 9% of pregnant women in UP consume the five recommended food groups, as per global recommendations.Ganesh Shankar Vidyarthi Memorial Medical College Hospital is one of the four high case load tertiary care facilities in Kanpur, UP, with an obstetrics and gynaecology (OBGY) outpatient department (OPD) of 2500-3000 consultations with delivery load of 250-300 deliveries per month and paediatric OPD of approximately 5400-6000 consultations per month. It was identified that pregnant women visiting the OPD for ANC were not receiving maternal nutrition-related services, and anthropometric measurements to assess nutritional status and gestational weight gain were also not done.The department of OBGY decided to apply the four-step Point of Care Quality Improvement (POCQI) approach using Plan-Do-Study-Act cycle for implementation of the maternal nutrition protocol during ANC.In April 2019, with the support of A&T, the hospital team applied the POCQI methodology to improve ANC service provision. By the end of 2019, the measurement and recording of anthropometric parameters increased to 84% and 74% for height and weight, respectively, from the baseline of zero. Hb testing increased from 58% to 84% and blood pressure (BP) monitoring from zero to 84%. Maternal nutrition counselling was delivered to 76% of the pregnant women visiting the OPD, which was a significant achievement for a new practice introduced into the system.The improved practices identified and implemented by the department are being sustained through active engagement of the staff and supportive leadership of the department of OBGY.

Banding-free balanced SSFP cardiac cine using frequency modulation and phase cycle redundancy.

PURPOSE: To develop a method for banding-free balanced SSFP cardiac cine imaging in a single breath-hold. METHODS: A frequency modulation scheme was designed for cardiac applications to eliminate the time normally required for steady-state stabilization between multiple phase-cycled acquisitions. Highly undersampled acquisitions were reconstructed using a model-based reconstruction that exploits redundancy both over time and between phase cycles. Performance of the methods was evaluated using both retrospective and prospective undersampling in scans with and without frequency modulation from four subjects. RESULTS: The proposed methods enabled balanced SSFP cardiac cine with three effective phase cycles in only 10 heartbeats. Images acquired with frequency modulation and with standard phase cycling were of similar quality. The combination of temporal and inter-acquisition similarity constraints reduced errors by approximately 45% compared to enforcing similarity constraints over time alone. CONCLUSIONS: In off-resonance conditions that preclude the acquisition of single-acquisition balanced SSFP, phase cycling can eliminate the dark bands in balanced SSFP cine cardiac imaging at the expense of some SNR efficiency. The proposed techniques permit these types of acquisitions in a single breath-hold.

Mitigation of near-band balanced steady-state free precession through-plane flow artifacts using partial dephasing.

PURPOSE: To mitigate artifacts from through-plane flow at the locations of steady-state stopbands in balanced steady-state free precession (SSFP) using partial dephasing. METHODS: A 60° range in the phase accrual during a TR was created over the voxel by slightly unbalancing the slice-select dephaser. The spectral profiles of SSFP with partial dephasing for various constant flow rates and during pulsatile flow were simulated to determine if partial dephasing decreases through-plane flow artifacts originating near SSFP dark bands while maintaining on-resonant signal. Simulations were then validated in a flow phantom. Lastly, phase-cycled SSFP cardiac cine images were acquired with and without partial dephasing in six subjects. RESULTS: Partial dephasing decreased the strength and non-linearity of the dependence of the signal at the stopbands on the through-plane flow rate. It thus mitigated hyper-enhancement from out-of-slice signal contributions and transient-related artifacts caused by variable flow both in the phantom and in vivo. In six volunteers, partial dephasing noticeably decreased artifacts in all of the phase-cycled cardiac cine datasets. CONCLUSION: Partial dephasing can mitigate the flow artifacts seen at the stopbands in balanced SSFP while maintaining the sequence's desired signal. By mitigating hyper-enhancement and transient-related artifacts originating from the stopbands, partial dephasing facilitates robust multiple-acquisition phase-cycled SSFP in the heart. Magn Reson Med 79:2944-2953, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Effect of image registration on longitudinal analysis of retinal nerve fiber layer thickness of non-human primates using Optical Coherence Tomography (OCT).

BACKGROUND: In this paper we determined the benefits of image registration on estimating longitudinal retinal nerve fiber layer thickness (RNFLT) changes. METHODS: RNFLT maps around the optic nerve head (ONH) of healthy primate eyes were measured using Optical Coherence Tomography (OCT) weekly for 30 weeks. One automatic algorithm based on mutual information (MI) and the other semi-automatic algorithm based on log-polar transform cross-correlation using manually segmented blood vessels (LPCC_MSBV), were used to register retinal maps longitudinally. We compared the precision and recall between manually segmented image pairs for the two algorithms using a linear mixed effects model. RESULTS: We found that the precision calculated between manually segmented image pairs following registration by LPCC_MSBV algorithm is significantly better than the one following registration by MI algorithm (p < <0.0001). Trend of the all-rings and temporal, superior, nasal and inferior (TSNI) quadrants average of RNFLT over time in healthy primate eyes are not affected by registration. RNFLT of clock hours 1, 2, and 10 showed significant change over 30 weeks (p = 0.0058, 0.0054, and 0.0298 for clock hours 1, 2 and 10 respectively) without registration, but stayed constant over time with registration. CONCLUSIONS: The LPCC_MSBV provides better registration of RNFLT maps recorded on different dates than the automatic MI algorithm. Registration of RNFLT maps can improve clinical analysis of glaucoma progression.