Faculty Bibliography

KEY POINTS/CONCLUSIONS:The corticoreticulospinal tract (CReST) is a descending motor pathway that reorganizes after corticospinal tract (CST) injury in animals. In humans, the pattern of CReST innervation to upper limb muscles has not been carefully examined in healthy individuals or individuals with CST injury. In the present study, we assessed CReST projections to an arm and hand muscle on the same side of the body in healthy and chronic stoke subjects using transcranial magnetic stimulation. We show that CReST connection strength to the muscles differs between healthy and stroke subjects, with stronger connections to the hand than arm in healthy subjects, and stronger connections to the arm than hand in stroke subjects. These results help us better understand CReST innervation patterns in the upper limb, and may point to its role in normal motor function and motor recovery in humans. ABSTRACT/UNASSIGNED:The corticoreticulospinal tract (CReST) is a major descending motor pathway in many animals, but little is known about its innervation patterns in proximal and distal upper extremity muscles in humans. The contralesional CReST furthermore reorganizes after corticospinal tract (CST) injury in animals, but it is less clear whether CReST innervation changes after stroke in humans. We thus examined CReST functional connectivity, connection strength, and modulation in an arm and hand muscle of healthy (n = 15) and chronic stroke (n = 16) subjects. We delivered transcranial magnetic stimulation to the contralesional hemisphere (assigned in healthy subjects) to elicit ipsilateral motor evoked potentials (iMEPs) from the paretic biceps (BIC) and first dorsal interosseous (FDI) muscle. We operationalized CReST functional connectivity as iMEP presence/absence, CReST projection strength as iMEP size and CReST modulation as change in iMEP size by head rotation. We found comparable CReST functional connectivity to the BICs and FDIs in both subject groups. However, the pattern of CReST connection strength to the muscles diverged between groups, with stronger connections to FDIs than BICs in healthy subjects and stronger connections to BICs than FDIs in stroke subjects. Head rotation modulated only FDI iMEPs of healthy subjects. Our findings indicate that the healthy CReST does not have a proximal innervation bias, and its strong FDI connections may have functional relevance to finger individuation. The reversed CReST innervation pattern in stroke subjects confirms its reorganization after CST injury, and its strong BIC connections may indicate upregulation for particular upper extremity muscles or their functional actions.

This study evaluated multiple previously-identified Continuous Performance Test-Third Edition (CPT-3) scores as embedded validity indicators (EVIs) among 201 adults undergoing neuropsychological evaluation for Attention-Deficit/Hyperactivity Disorder (ADHD) divided into valid (n = 169) and invalid (n = 32) groups based on seven criterion measures. Although 6/10 CPT-3 scores accurately detected invalidity, only two reached minimally acceptable classification accuracy of ≥0.70. The remaining four had unacceptably low accuracy (AUCs = 0.62-0.69) with 0.19-0.41 sensitivity at ≥0.90 specificity. Composite scores did not provide better classification accuracy than individual CPT-3 scores. In sum, CPT-3 individual and composite scores generally are not accurate PVTs among adults undergoing clinical evaluation for ADHD.

INTRODUCTION/BACKGROUND:Many patients admitted to hospitals with acute trauma have positive serum blood alcohol levels. Published associations between alcohol use, injury patterns, and outcomes are inconsistent. We sought to further delineate the impact of alcohol use and alcohol withdrawal on hospital outcomes amongst acute trauma patients. METHODS:We performed a retrospective analysis of adult trauma patients hospitalized at a suburban level 1 trauma center between January 2015 and September 2019 with a blood alcohol level measurement and/or classification as alcohol withdrawal syndrome (AWS). Patients were separated into three groups: BAL ≤10 mg/dL, BAL >10 mg/dL, and alcohol withdrawal syndrome (AWS). RESULTS:Overall, 3896 patients met study criteria with 75.6% BAL ≤10, 23.2% BAL >10, and 1.2% AWS. The median age was significantly different (BAL ≤ 10: 59 years, BAL > 10: 44 years, AWS: 53.5 years). Alcohol withdrawal was experienced by patients with BAL ≤10 and BAL >10. While injury severity and mortality were similar across all 3 groups, AWS patients experienced significantly longer hospital and ICU lengths of stay, unplanned ICU admission, need for mechanical ventilation, and higher rates of complications. Patients with AWS had high rates of acute neuropsychiatric symptoms, complicating their management. CONCLUSIONS:Except for mortality, AWS patients experienced worse outcomes. The complex nature of alcohol withdrawal cases, including the possibility of developing AWS despite a negative BAL on admission, emphasizes the need for early assessment for alcohol withdrawal risk factors and input from specialists.

INTRODUCTION/BACKGROUND:The recurrent laryngeal nerves(RLN) run immediately posterior to the thyroid capsule and could be injured during thyroid radiofrequency ablation(RFA). This study assesses whether RLN functional integrity is altered during RFA using continuous intraoperative neuromonitoring(CIONM). METHODS:Prospective case series of twenty nodules treated with RFA under general anesthesia utilizing the laryngeal adductor reflex(LAR) for CIONM. RESULTS:Thirteen nodules abutted the posterior thyroid capsule and 'danger triangle' for RLN injury. The ablative field did not breach the posterior capsule; 40 W was the maximal power used adjacent to the capsule. No patient experienced significant LAR amplitude alterations. Pre and postoperative laryngoscopy and voice assessments were comparable. At 12 months' median follow-up, no patient displayed posterior nodule regrowth. CONCLUSIONS:This prospective case series supports the premise that benign nodule RFA is safe with regards to RLN functional integrity provided the posterior capsule is not breached by the ablation zone and posterior power is ≤ 40 W.

PURPOSE/OBJECTIVE:The aim of this study was to investigate the use of spectral analysis (SA) for voxel-wise analysis of TSPO PET imaging studies. TSPO PET quantification is methodologically complicated by the heterogeneity of TSPO expression and its cell-dependent modulation during neuroinflammatory response. Compartmental models to account for this complexity exist, but they are unreliable at the high noise typical of voxel data. On the contrary, SA is noise-robust for parametric mapping and provides useful information about tracer kinetics with a free compartmental structure. PROCEDURES/METHODS:SA impulse response function (IRF) calculated at 90 min after tracer injection was used as main parameter of interest in 3 independent PET imaging studies to investigate its sensitivity to (1) a TSPO genetic polymorphism (rs6971) known to affect tracer binding in a cross-sectional analysis of healthy controls scanned with [11C]PBR28 PET; (2) TSPO density with [11C]PBR28 in a competitive blocking study with a TSPO blocker, XBD173; and (3) the higher affinity of a second radiotracer for TSPO, by using data from a head-to-head comparison between [11C]PBR28 and [11C]ER176 scans. RESULTS:(Pearson's r = 0.76 ± 0.32). Finally, SA-IRF estimates for [11C]ER176 were significantly higher than [11C]PBR28 ones, consistent with the higher amount of specific binding of the former tracer. CONCLUSIONS:SA-IRF can be used for voxel-wise quantification of TSPO PET data because it generates high-quality parametric maps, it is sensitive to TSPO availability and genotype, and it accounts for the complexity of TSPO tracer kinetics with no additional assumptions.

Axial disorders, including postural deformities, postural instability, and gait disturbances, are among the most disabling symptoms of Parkinson's disease (PD). Equistasi®, a wearable proprioceptive stabilizer device, has been proposed as neurological rehabilitative device for this set of symptoms. To investigate the effects of the device on gait and balance, 24 participants affected by PD were enrolled in this crossover double-dummy, randomized, controlled study. Subjects were assessed four times before and after 8 weeks treatment with either active or placebo device; one-month wash-out was taken between treatments, in a 20-week timeframe. Gait analysis and instrumented Romberg test were performed with the aid of a sterofotogrammetric system and two force plates. Joint kinematics, spatiotemporal parameters of gait and center of pressure parameters were extracted. Paired T-test (p < 0.05) was adopted after evidence of normality to compare the variables across different acquisition sessions; Wilcoxon was adopted for non-normal distributions. Before and after the treatment with the active device, statistically significant improvements were observed in trunk flexion extension and in the ankle dorsi-plantarflexion. Regarding balance assessment, significant improvements were reported at the frequencies corresponding to vestibular system. These findings may open new possibilities on PD's rehabilitative interventions. Research question, tailored design of the study, experimental acquisition overview, main findings, and conclusions.

Dopamine receptors are abundant along the central nigrostriatal tract and are expressed as 5 subtypes in two receptor families. In PD, compensatory changes in dopamine receptors emerge as a consequence of the loss of dopamine nerve terminals or dopaminergic pharmacotherapy. We performed a systematic review and meta-analysis of the available PET and single-photon emission computed tomography studies that have investigated dopamine receptors in PD, PSP and MSA. The inclusion criteria were studies including human PET or single-photon emission computed tomography imaging; dopamine receptor tracers (D1-like or D2-like) and idiopathic PD, PSP, or MSA patients compared with healthy controls. The 67 included D2-like studies had 1925 patients. Data were insufficient for an analysis of D1-like studies. PD patients had higher striatal binding early in the disease, but after a disease duration of 4.36 years, PD patients had lower binding values than healthy controls. Striatal D2R binding was highest in unmedicated early PD patients and in the striatum contralateral to the predominant motor symptoms. PSP and MSA-P patients had lower striatal D2R binding than PD patients (14.2% and 21.8%, respectively). There is initial upregulation of striatal D2Rs in PD, which downregulate on average 4 years after motor symptom onset, possibly because of agonist-induced effects. The consistent upregulation of D2Rs in the PD striatum contralateral to the predominant motor symptoms indicates that receptor changes are driven by neurodegeneration and loss of striatal neuropil. Both PSP and MSA patients have clearly lower striatal D2R binding values than PD patients, which offers an opportunity for differential diagnostics. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

This study examined toddlers' autonomy- and connectedness-oriented behaviors and mothers' encouragement of autonomy and connectedness in two cohorts (1995 and 2008) in urban China. Observational data were collected from Chinese children and their mothers in a laboratory free play session. The results showed that compared with children in the 1995 cohort (207 children, 95 boys, Mage = 24.09 months), children in the 2008 cohort (281 children, 144 boys, Mage = 24.34 months) displayed fewer connectedness-oriented behaviors and spent more time on autonomous activities. Compared with mothers in the 1995 cohort (45% with a college education), mothers in the 2008 cohort (43.4% with a college education) were less likely to display involvement in children's activities and more likely to encourage child autonomy. The results suggest that macrolevel contexts may play an important role in shaping parenting and children's behaviors. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Purpose of Review/UNASSIGNED:In 2019, over 50 million Americans were expected to use wearables at least monthly. The technologies have varied capabilities, with many designed to monitor health conditions. We present a narrative review to raise awareness of wearable technologies that may be relevant to the field of neurology. We also discuss the implications of these wearables for our patients and briefly discuss issues related to researching new wearable technologies. Recent Findings/UNASSIGNED:There are a variety of wearables for neurologic conditions, e.g., stroke (for potential arrhythmia capture), epilepsy, Parkinson disease, and sleep. Research is being performed to capture the risk of neuropsychiatric relapse. However, data are limited and adherence to these wearables is often poorly studied. Summary/UNASSIGNED:The care of neurology patients may ultimately be improved with the use of wearable technologies. More research needs to examine efficacy and implementation strategies.

Voluntary rapid eye movements (saccades) redirect the fovea toward objects of visual interest. The saccadic system can be considered as a dual-mode system: in one mode the eye is fixating, in the other it is making a saccade. In this review, we consider two examples of dysfunctional saccades, interrupted saccades in late-onset Tay-Sachs disease and gaze-position dependent opsoclonus after concussion, which fail to properly shift between fixation and saccade modes. Insights and benefits gained from bi-directional collaborative exchange between clinical and basic scientists are emphasized. In the case of interrupted saccades, existing mathematical models were sufficiently detailed to provide support for the cause of interrupted saccades. In the case of gaze-position dependent opsoclonus, existing models could not explain the behavior, but further development provided a reasonable hypothesis for the mechanism underlying the behavior. Collaboration between clinical and basic science is a rich source of progress for developing biologically plausible models and understanding neurological disease. Approaching a clinical problem with a specific hypothesis (model) in mind often prompts new experimental tests and provides insights into basic mechanisms.