Cerebrovascular reactivity dispersion as a new biomarker of recent stroke symptomatology in moyamoya

Background

Moyamoya disease (MMD) is a non-atherosclerotic intracranial steno-occlusive condition placing patients at high risk for ischemic stroke. Direct and indirect surgical revascularization can improve blood flow in MMD; however, randomized trials demonstrating efficacy have not been performed and biomarkers of parenchymal hemodynamic impairment are needed to triage patients for interventions and evaluate post-surgical efficacy. We test the hypothesis that hypercapnia-induced maximum cerebrovascular reactivity (CVR MAX ) and the more novel indicator cerebrovascular reactivity (CVR) response time (CVR DELAY ), both assessed from time-regression analyses of non-invasive hypercapnic imaging, correlate with recent focal ischemic symptoms.

Methods

Hypercapnic reactivity medical resonance imaging (blood oxygenation level-dependent; echo time=35ms; spatial resolution=3.5×3.5×3.5mm) and catheter angiography assessments of cortical reserve capacity and vascular patency, respectively, in MMD participants (n=73) were performed in sequence. Time regression analyses were applied to quantify CVR MAX and CVR DELAY . Symptomatology information for each hemisphere (n=109) was categorized into symptomatic (ischemic symptoms within six months) or asymptomatic (no history of ischemic symptoms) and logistic regression analysis assessed the association of CVR metrics with ischemic symptoms after controlling for age and sex.

Results

Symptomatic hemispheres displayed lengthened CVR DELAY (p<0.001), which was more discriminatory between hemispheres than CVR MAX (p=0.037). CVR DELAY (p<0.001), but not CVR MAX (p=0.127), was found to be sensitively related to age in asymptomatic tissue (0.33-unit increase/year); age-dependent normative ranges are presented to enable quantitative assessment of patient-specific impairment. Furthermore, the area under the receiver operating characteristic curves shows that CVR DELAY predicts ischemic symptoms (p<0.001), whereas CVR MAX does not (p=0.056).

Conclusion

Findings support that CVR metrics are uniquely altered in hemispheres with recent ischemic symptoms, motivating the investigation of CVR as a surrogate of ischemic symptomatology and treatment efficacy.

Alterations in Cerebrospinal Fluid Urea Occur in Late Manifest Huntington's Disease

Background

Huntington's disease (HD) is a neurodegenerative disorder caused by expanded cytosine-adenine-guanine (CAG) repeats in the Huntingtin gene, resulting in the production of mutant huntingtin proteins (mHTT). Previous research has identified urea as a key metabolite elevated in HD animal models and postmortem tissues of HD patients. However, the relationship between disease course and urea elevations, along with the molecular mechanisms responsible for these disturbances remain unknown.

Objective

To better understand the molecular disturbances and timing of urea cycle metabolism across different stages in HD.

Methods

We completed a global metabolomic profile of cerebrospinal fluid (CSF) from individuals who were at several stages of disease: pre-manifest (PRE), manifest (MAN), and late manifest (LATE) HD participants, and compared to controls.

Results

Approximately 500 metabolites were significantly altered in PRE participants compared to controls, although no significant differences in CSF urea or urea metabolites were observed. CSF urea was significantly elevated in LATE participants only. There were no changes in the urea metabolites citrulline, ornithine, and arginine.

Conclusions

Overall, our study confirms that CSF elevations occur late in the HD course, and these changes may reflect accumulating deficits in cellular energy metabolism.

Huntington disease exacerbates action impulses

Background

Impulsivity is a common clinical feature of Huntington disease (HD), but the underlying cognitive dynamics of impulse control in this population have not been well-studied.

Objective

To investigate the temporal dynamics of action impulse control in HD patients using an inhibitory action control task.

Methods

Sixteen motor manifest HD patients and seventeen age-matched healthy controls (HC) completed the action control task. We applied the activation-suppression theoretical model and distributional analytic techniques to differentiate the strength of fast impulses from their top-down suppression.

Results

Overall, HD patients produced slower and less accurate reactions than HCs. HD patients also exhibited an exacerbated interference effect, as evidenced by a greater slowing of RT on non-corresponding compared to corresponding trials. HD patients made more fast, impulsive errors than HC, evidenced by significantly lower accuracy on their fastest reaction time trials. The slope reduction of interference effects as reactions slowed was similar between HD and controls, indicating preserved impulse suppression.

Conclusion

Our results indicate that patients with HD show a greater susceptibility to act rapidly on incorrect motor impulses but preserved proficiency of top-down suppression. Further research is needed to determine how these findings relate to clinical behavioral symptoms.

Risk-Taking Behaviors in Huntington's Disease

BACKGROUND

Risky behaviors are common in Huntington's disease (HD) and can lead to significant adverse consequences. However, the prevalence and scope of these symptoms have not been studied systematically, and no empirically validated measures are available to screen for them.

OBJECTIVE

To test a novel screening tool designed to assess risk-taking behaviors in HD.

METHODS

We administered the Risk Behavior Questionnaire (RBQ-HD) to HD patients and caregivers at Vanderbilt University Medical Center between 2018-2019. Patients completed the questionnaire based on self-report; caregivers provided collateral reports. Clinical and demographic information were obtained from the electronic medical record.

RESULTS

60 patients and 60 caregivers completed the RBQ-HD. 80% of patients (n = 48) and 91.7% of caregivers (n = 60) reported at least one risky behavior. Adverse social behaviors, impulsive/compulsive behaviors, and reckless driving were the most common behavioral domains reported. Male patients were more likely to report risky behaviors than females (92.3% vs. 70.6%, p = 0.04). The number of risky behaviors reported by patients and caregivers was negatively correlated with patient age (r = -0.32, p = 0.01; r = -0.47, p = 0.0001, respectively). Patient and caregiver reports were highly correlated in matched pairs (n = 30; r = 0.63, p = 0.0002).

CONCLUSION

These findings emphasize that risky behaviors are highly prevalent in HD and can be effectively identified through the use of a novel screening measure. We hypothesize that early pathological involvement of frontostriatal and mesolimbic networks may be important factors in the development of these behaviors.

Abstract P4-07-04: Detecting early breast cancer by the combination of five serum microRNAs and its possibility of prediction of pathological complete response in neoadjuvant chemotherapy

[Background] It is recently reported that microRNAs (miRNAs) are stably present in serum and potentially useful in the diagnosis and evaluation of treatment of cancer.

[Materials and Methods] Serum samples of breast cancer before treatment (n=1280) between 2008 and 2014 were obtained from National Cancer Center Hospital and controls (n=3348) were obtained from collaborative institutes. Additionally, the serum sample of patients who received neoadjuvant chemotherapy (NAC) and surgery between last chemotherapy administration and surgery were collected. A comprehensive quantitative expression analysis of miRNA was performed using the by DNA chip “3D-Gene® (Toray Industries Inc.)” Clinicopathological data was retrieved from medical records. Pathological complete response (pCR) was defined as the absence of residual invasive and in situ cancer of the resected breast specimen and all sampled regional lymph nodes.

[Results] Serum samples before treatment of breast cancer patients (n=74), non-cancer controls and patients with other cancers were used (n=2007) in a training set. The rest except for samples after NAC were used in a test set. The formula with the combination of five miRNAs (miR-1246, miR-1307-3p, miR-4634, miR-6861-5p, and miR-6875-5p) was found to be able to detect breast cancer (BCmiR set). BCmiR set had a sensitivity of 97.3%, specificity of 82.9% and accuracy of 89.7% in the test cohort. BCmiR set could detect breast cancer in the non-invasive stage (sensitivity of 98.0% for Tis).

In the breast cancer patients, 91 patients received NAC and surgery. Median age of NAC patients was 49 years (range 28-77). Forty-two patients were hormone receptor-positive (HR+) and HER2-negative (HER2-), 24 were HR+ and HER2-positive (HER2+), 11 were hormone receptor-negative (HR-) and HER2+ and 14 were HR- and HER2-. pCR was observed in 19 (20.9%) of NAC patients. pCR in each subtypes were 3 (7.7%) in HR+ and HER2-, 6 (33.3%) in HR+ and HER2+, 4 (57.1%) in HR- and HER2+ and 3 (27.3%) in HR- and HER2-. Serum after NAC were obtained from 19 pCR patients and 71 non-pCR patients. When we applied BCmiR set to the serum samples after NAC, the average diagnostic index (cut-off value=0) in pCR patients was significantly lower than that in non-pCR patients (pCR, -0.30±0.84; non-pCR, 0.31±1.15; p=0.03). In fact, 57.9% of pCR patients were classified into non-breast cancer. However, 40.8% of non-pCR patients were misclassified into non-breast cancer.

[Conclusion] The combination of five miRNAs (BCmiR set) measured from serum can be used to detect breast cancer. BCmiR set has potential to predict pCR in patients who received NAC. The further analysis to predict pCR is underway and further results will be presented in the symposium.

Citation Format: Shimomura A, Shiino S, Kawauchi J, Takizawa S, Sakamoto H, Shimizu C, Takeshita F, Niida S, Kinoshita T, Tamura K, Ochiya T. Detecting early breast cancer by the combination of five serum microRNAs and its possibility of prediction of pathological complete response in neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-07-04.

[Cerebellar infarction due to vertebral artery dissection in a girl]

We report here a case of vertebral artery dissection, which is rare in childhood. A 12-year-old, previous healthy girl was admitted to our hospital with symptoms of vertigo, tinnitus, hearing loss, nausea and vomiting. Although there was neither higher cortical dysfunction, motor weakness, sensory disturbance nor slurred speech. She could not stand up because of severe vertigo. Cranial magnetic resonance imaging (MRI) revealed a subacute cerebellar infarct. A left vertebral artery angiogram on the hospital day 3 demonstrated a sharp narrowing at the C1-C2 level. After an anticoagulant therapy for about 2 weeks, all the symptoms disappeared except for mild tinnitus. Two months later, a left vertebral artery angiogram showed an abrupt occlusion at the C1 level. MRI T1-weighted images demonstrated a thrombus within the false lumen of the dissected vessels. A flow void revealed the patency of the residual true lumen. From these findings, we made a diagnosis of vertebral artery dissection, which was considered to have caused cerebellar infarction. The patient was mostly normal at discharge, and 100 mg/day of aspirin has been given until present.

Two types of electrochemical nitric oxide (NO) sensing systems with heat-denatured Cyt C and radical scavenger PTIO

To develop an in situ NO sensing system for primarily biological and medical uses, two types of NO sensing materials, which may be coupled with an electrochemical reaction for signal transduction, have been investigated. Heat-denatured Cyt C and a radical scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetra methyl imidazoline-1-oxyl-3-oxide (C-PTIO) were found to be effective and were incorporated into electrochemical sensing systems. Heat-denatured Cyt C deposited on a 4-mercaptopyridine modified gold electrode responded to NO with an increase of cathodic current through electrochemical reduction of Cyt C (Fe3+), when the electrode potential was controlled at 0 mV vs Ag/AgCl. The dynamic range of the sensing system was 0.5-4 microM. The sensing system with C-PTIO exhibited an anodic output in response to NO at 0.7 V vs Ag/AgCl, and showed a wider dynamic range from 0.05 to 100 microM.