Symptomatic Carotid Atheroma Inflammation Lumen-stenosis score compared with Oxford and Essen risk scores to predict recurrent stroke in symptomatic carotid stenosis.

BACKGROUND: The Oxford Carotid Stenosis tool (OCST) and Essen Stroke Risk Score (ESRS) are validated to predict recurrent stroke in patients with and without carotid stenosis. The Symptomatic Carotid Atheroma Inflammation Lumen stenosis (SCAIL) score combines stenosis and plaque inflammation on fluorodeoxyglucose positron-emission tomography (18FDG-PET). We compared SCAIL with OCST and ESRS to predict ipsilateral stroke recurrence in symptomatic carotid stenosis. PATIENTS AND METHODS: We pooled three prospective cohort studies of patients with recent (<30 days) non-severe ischaemic stroke/TIA and internal carotid artery stenosis (>50%). All patients had carotid 18FDG-PET/CT angiography and late follow-up, with censoring at carotid revascularisation. RESULTS: Of 212 included patients, 16 post-PET ipsilateral recurrent strokes occurred in 343 patient-years follow-up (median 42 days (IQR 13-815)).Baseline SCAIL predicted recurrent stroke (unadjusted hazard ratio [HR] 1.96, CI 1.20-3.22, p = 0.007, adjusted HR 2.37, CI 1.31-4.29, p = 0.004). The HR for OCST was 0.996 (CI 0.987-1.006, p = 0.49) and for ESRS was 1.26 (CI 0.87-1.82, p = 0.23) (all per 1-point score increase). C-statistics were: SCAIL 0.66 (CI 0.51-0.80), OCST 0.52 (CI 0.40-0.64), ESRS 0.61 (CI 0.48-0.74). Compared with ESRS, addition of plaque inflammation (SUVmax) to ESRS improved risk prediction when analysed continuously (HR 1.51, CI 1.05-2.16, p = 0.03) and categorically (ptrend = 0.005 for risk increase across groups; HR 3.31, CI 1.42-7.72, p = 0.006; net reclassification improvement 10%). Findings were unchanged by further addition of carotid stenosis. CONCLUSIONS: SCAIL predicted recurrent stroke, had discrimination better than chance, and improved the prognostic utility of ESRS, suggesting that measuring plaque inflammation may improve risk stratification in carotid stenosis.

Soluble low-density lipoprotein receptor-related protein 1 as a surrogate marker of carotid plaque inflammation assessed by 18F-FDG PET in patients with a recent ischemic stroke.

BACKGROUND: 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) identifies carotid plaque inflammation and predicts stroke recurrence. AIM: Our aim was to evaluate the performance of soluble low-density lipoprotein receptor-related protein 1 (sLRP1) as an indicator of carotid plaque inflammation. METHODS: A prospective study was conducted among adult patients with recent (< 7 days) anterior circulation ischemic stroke and at least one atherosclerotic plaque in the ipsilateral internal carotid artery. Patients underwent an early (< 15 days from inclusion) 18F-FDG PET, and the maximum standardized uptake value (SUVmax) within the plaque was measured. sLRP1 levels were measured in plasma samples by ELISA. The association of sLRP1 with SUVmax was assessed using bivariate and multivariable linear regression analyses. Hazard ratios (HR) were estimated with Cox regression to evaluate the association between circulating sLRP1 and stroke recurrence. RESULTS: The study was conducted with 64 participants, of which 57.8% had ≥ 50% carotid stenosis. The multivariable linear and logistic regression analyses showed that sLRP1 was independently associated with (i) SUVmax within the plaque (ß = 0.159, 95% CI 0.062-0.257, p = 0.002) and (ii) a probability of presenting SUVmax ≥ 2.85 g/mL (OR = 1.31, 95% CI 1.00-1.01, p = 0.046), respectively. Participants with stroke recurrence showed higher sLRP1 levels at baseline [6447 ng/mL (4897-11163) vs. 3713 ng/mL (2793-4730); p = 0.018]. CONCLUSIONS: sLRP1 was independently associated with carotid plaque inflammation as measured by 18F-FDG PET in patients with recent ischemic stroke and carotid atherosclerosis.

Electronegative LDL Is Associated with Plaque Vulnerability in Patients with Ischemic Stroke and Carotid Atherosclerosis.

Owing to the high risk of recurrence, identifying indicators of carotid plaque vulnerability in atherothrombotic ischemic stroke is essential. In this study, we aimed to identify modified LDLs and antioxidant enzymes associated with plaque vulnerability in plasma from patients with a recent ischemic stroke and carotid atherosclerosis. Patients underwent an ultrasound, a CT-angiography, and an 18F-FDG PET. A blood sample was obtained from patients (n = 64, 57.8% with stenosis ≥50%) and healthy controls (n = 24). Compared to the controls, patients showed lower levels of total cholesterol, LDL cholesterol, HDL cholesterol, apolipoprotein B (apoB), apoA-I, apoA-II, and apoE, and higher levels of apoJ. Patients showed lower platelet-activating factor acetylhydrolase (PAF-AH) and paraoxonase-1 (PON-1) enzymatic activities in HDL, and higher plasma levels of oxidized LDL (oxLDL) and electronegative LDL (LDL(-)). The only difference between patients with stenosis ≥50% and <50% was the proportion of LDL(-). In a multivariable logistic regression analysis, the levels of LDL(-), but not of oxLDL, were independently associated with the degree of carotid stenosis (OR: 5.40, CI: 1.15-25.44, p < 0.033), the presence of hypoechoic plaque (OR: 7.52, CI: 1.26-44.83, p < 0.027), and of diffuse neovessels (OR: 10.77, CI: 1.21-95.93, p < 0.033), indicating that an increased proportion of LDL(-) is associated with vulnerable atherosclerotic plaque.

Brain metabolic changes in patients with disseminated malignant melanoma under immunotherapy.

Although there is evidence that chemotherapy can have side effects on metabolism and brain function, there are few studies on the occurrence of these side effects with immunotherapy. The present study was conducted to assess whether brain metabolic changes occur in patients with malignant melanoma under immunotherapy. Thirty-nine patients after surgical intervention and with a diagnosis of malignant melanoma were retrospectively included and were divided into two groups: one group under the first-line therapy with anti-programmed cell death-1 ± anti-cytotoxic T lymphocyte antigen-4 monoclonal antibodies and the other group without any treatment after surgery, which served as a control. Basal and follow-up whole body and brain 2-[ 18 F]fluoro-2-deoxy-D-glucose ( 18 F]FDG) PET/computed tomography (CT) studies were performed. Changes in brain glucose metabolism after treatment initiation of the immunotherapy group were compared with the findings in the control group. In addition, longitudinal regression analysis to investigate whether the time under immunotherapy influenced the changes of brain metabolism was performed. None of the patients presented cognitive impairment or other neurological alterations between basal and follow-up brain [ 18 F]FDG PET/CT examinations. The statistical analysis revealed a significant relative SUV (SUVr)-loss in the left frontal region in patients of the immunotherapy group compared with the control group, with radjusted = -0.62 and P = 0.008. Severity of SUVr-loss was correlated with duration of treatment. Patients with disseminated malignant melanoma receiving immunotherapy may present a decrease of brain metabolism in the left frontal region, which is related with time-under-treatment, without any clinical evidence of neurological disorder.

Association of Plaque Inflammation With Stroke Recurrence in Patients With Unproven Benefit From Carotid Revascularization.

BACKGROUND AND OBJECTIVES: In pooled analyses of endarterectomy trials for symptomatic carotid stenosis, several subgroups experienced no net benefit from revascularization. The validated symptomatic carotid atheroma inflammation lumen-stenosis (SCAIL) score includes stenosis severity and inflammation measured by PET and improves the identification of patients with recurrent stroke compared with lumen-stenosis alone. We investigated whether the SCAIL score improves the identification of recurrent stroke in subgroups with uncertain benefit from revascularization in endarterectomy trials. METHODS: We did an individual-participant data pooled analysis of 3 prospective cohort studies (Dublin Carotid Atherosclerosis Study [DUCASS], 2008-2011; Biomarkers and Imaging of Vulnerable Atherosclerosis in Symptomatic Carotid Artery Disease [BIOVASC], 2014-2018; Barcelona Plaque Study, 2015-2018). Eligible patients had a recent nonsevere (modified Rankin Scale score ≤3) anterior circulation ischemic stroke/TIA and ipsilateral mild carotid stenosis (<50%); ipsilateral moderate carotid stenosis (50%-69%) plus at least 1 of female sex, age <65 years, diabetes mellitus, TIA, or delay >14 days to revascularization; or monocular loss of vision. Patients underwent coregistered carotid 18F-fluorodeoxyglucosePET/CT angiography (≤7 days from inclusion). The primary outcome was 90-day ipsilateral ischemic stroke. Multivariable Cox regression modeling was performed. RESULTS: We included 135 patients. All patients started optimal modern-era medical treatment at admission, and 62 (45.9%) underwent carotid revascularization (36 within the first 14 days and 26 beyond). At 90 days, 18 (13.3%) patients had experienced at least 1 stroke recurrence. The risk of recurrence increased progressively according to the SCAIL score (0.0% in patients scoring 0-1, 15.1% scoring 2-3, and 26.7% scoring 4-5; p = 0.04). The adjusted (age, smoking, hypertension, diabetes, carotid revascularization, antiplatelets and statins) hazard ratio for ipsilateral recurrent stroke per 1-point SCAIL increase was 2.16 (95% CI 1.32-3.53; p = 0.002). A score ≥2 had a sensitivity of 100% for recurrence. DISCUSSION: The SCAIL score improved the identification of early recurrent stroke in subgroups who did not experience benefit in endarterectomy trials. Randomized trials are needed to test whether a combined stenosis-inflammation strategy will improve selection for carotid revascularization when benefit is currently uncertain. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, in patients with recent anterior circulation ischemic stroke who do not benefit from carotid revascularization, the SCAIL score accurately distinguishes those at risk for recurrent ipsilateral ischemic stroke.

Plasma sICAM-1 as a Biomarker of Carotid Plaque Inflammation in Patients with a Recent Ischemic Stroke.

18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) identifies carotid plaque inflammation and predicts stroke recurrence in patients with atherothrombotic stroke. The aim of the study was to identify plasma inflammatory biomarkers associated with plaque inflammation according to 18F-FDG uptake. We conducted a prospective study of consecutive adult patients with a recent (< 7 days) anterior circulation ischemic stroke and at least one atherosclerotic plaque in the ipsilateral internal carotid artery. We included 64 patients, 57.8% of whom showed a carotid stenosis ≥ 50%. All patients underwent an early (< 15 days from inclusion) 18F-FDG PET, and a blood sample was obtained at days 7 ± 1 from the stroke. The plasma concentration of 16 inflammation-related molecules was analyzed in a Luminex using xMAP technology. Multivariable linear regression was used to assess the association between plasma biomarkers and the standardized uptake value (SUV) of 18F-FDG uptake. Soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), and fractalkine (FKN) were independently associated with plaque inflammation (ß = 0.121, 95% CI 0.061-0.181, p < 0.001; ß = 0.144, 95% CI 0.012-0.276, p = 0.033; ß = 0.136, 95% CI 0.037-0.235, p = 0.008). In a multivariable logistic regression analysis, sICAM-1 was associated with SUVmax ≥ 2.85 (OR = 1.02, 95% CI 1.00-1.03, p = 0.020). Multivariable Cox regression was used to assess the association between biomarkers and stroke recurrence. sICAM-1 was associated with stroke recurrence (HR = 1.03, 95% CI 1.00-1.05, p = 0.002). In summary, elevated concentrations of sICAM-1 were associated with carotid plaque inflammation and an increased risk of stroke recurrence in patients with recent ischemic stroke and carotid atherosclerosis.

Carotid Plaque Inflammation Imaged by PET and Prediction of Recurrent Stroke at 5 Years.

BACKGROUND AND OBJECTIVES: To determine whether carotid plaque inflammation identified by 18F-fluorodeoxyglucose (18FDG)-PET is associated with late (5-year) recurrent stroke. METHODS: We did an individual-participant data pooled analysis of 3 prospective studies with near-identical study methods. Eligible patients had recent nonsevere (modified Rankin Scale score ≤3) ischemic stroke/TIA and ipsilateral carotid stenosis (50%-99%). Participants underwent carotid 18FDG-PET/CT angiography ≤14 days after recruitment. 18FDG uptake was expressed as maximum standardized uptake value (SUVmax) in the axial single hottest slice of symptomatic plaque. We calculated the previously validated Symptomatic Carotid Atheroma Inflammation Lumen-Stenosis (SCAIL) score, which incorporates a measure of stenosis severity and 18FDG uptake. The primary outcome was 5-year recurrent ipsilateral ischemic stroke after PET imaging. RESULTS: Of 183 eligible patients, 181 patients completed follow-up (98.9%). The median duration of follow-up was 4.9 years (interquartile range 3.3-6.4 years, cumulative follow-up period 901.8 patient-years). After PET imaging, 17 patients had a recurrent ipsilateral ischemic strokes at 5 years (recurrence rate 9.4%, 95% confidence interval [CI] 5.6%-14.6%). Baseline plaque SUVmax independently predicted 5-year ipsilateral recurrent stroke after adjustment for age, sex, carotid revascularization, stenosis severity, NIH Stroke Scale score, and diabetes mellitus (adjusted hazard ratio [HR] 1.98, 95% CI 1.10-3.56, p = 0.02 per 1-g/mL increase in SUVmax). On multivariable Cox regression, SCAIL score predicted 5-year ipsilateral stroke (adjusted HR 2.73 per 1-point increase, 95% CI 1.52-4.90, p = 0.001). DISCUSSION: Plaque inflammation-related 18FDG uptake improved identification of 5-year recurrent ipsilateral ischemic stroke. Addition of plaque inflammation to current selection strategies may target patients most likely to have late and early benefit from carotid revascularization. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in individuals with recent ischemic stroke/TIA and ipsilateral carotid stenosis, carotid plaque inflammation-related 18FDG uptake on PET/CT angiography was associated with 5-year recurrent ipsilateral stroke.

"The added value of 18f-FDG PET/CT in the assessment of onset and steroid resistant polimyalgia rheumatica".

PMR is a common inflammatory rheumatic disease. Although its clinical characteristics are fully recognized, no specific test for its diagnosis has been established to date. Several studies have described a wide variety of diseases that present with polymyalgic symptoms. A 18FDG-PET/CT scan could help to deal with these differential diagnoses. The goal of our study is to describe the findings of the 18FDG-PET/CT scan in a cohort of PMR patients and to detail how the 18FDG-PET/CT scan improves accuracy when diagnosing other underlying conditions. This cross-sectional study enrolled patients with a diagnosis of PMR who underwent to a 18FDG-PET/CT scan to rule out other diagnosis. The 18FDG-PET/CT scan was performed either following clinical criteria at the onset of clinical symptoms or when the patient became PMR steroid resistant. Patients' demographic, clinical and analytical data at the moment of the 18FDG-PET/CT scan were recorded. The final diagnosis was confirmed according to clinical judgement. A total of 103 patients with PMR were included. In 49.51% of patients, the 18FDG-PET/CT scan was ordered to study resistance to steroid therapy. The final diagnoses of patients were PMR in 70.9% patients, large vessel vasculitis in 15.5%, neoplasms 4.8% and another diagnosis in the rest. The 18FDG-PET/CT scan is a very useful technique for the study of Polymyalgia Rheumatica, not only to help in the diagnostic process, but also due to its role in the identification of a variety of PMR-like patrons.

Brain metabolic changes in patients with treatment resistant schizophrenia treated with deep brain stimulation: A series of cases.

Deep brain stimulation (DBS) has been found to be effective in treatment resistant neurological and psychiatric disorders. So far there has been only one completed trial in schizophrenia, in which seven treatment resistant patients received DBS in the subgenual anterior cingulate cortex (sgACC, N = 4) or the nucleus accumbens (NAc, N = 3); four met symptomatic response criteria over the trial period. Six patients underwent 18 F-FDG PET at baseline and after at least 6 months of stimulation. Individual patient analysis indicated that DBS to both the sgACC and NAc was associated with local and distant changes in glucose metabolism. Increments and decrements of brain activity were observed in regions that included the medial prefrontal cortex, the dorsolateral prefrontal cortex, the anterior cingulate cortex, the caudate nucleus, the NAc, the hippocampus and the thalamus. Increased activity appeared to be associated with clinical improvement. These preliminary findings suggest that DBS acts by modulating cerebral activity in the cortico-basal-thalamic-cortical circuit in patients with schizophrenia who show improvement in psychotic symptoms.

The Added Value of Tau-PET in the Assessment of Progressive Supranuclear Palsy.

Progressive supranuclear palsy (PSP) is rare neurodegenerative disorder characterized by deposition of fibrillar aggregates of 4R tau-protein in neurons and glial cells. This disorder is underdiagnosed due to the overlap of the clinical syndrome with other related conditions. The clinical manifestations include cognitive impairment associated with behavioral changes, akinetic rigid syndrome, and prominent oculomotor dysfunction. We present the F-FDG and F-THK5351 PET images of a 71-year-old man diagnosed of probable PSP. This image highlights the hopeful results of the new tau-PET ligands radiotracers, because it allows to assess the distribution of tau-protein over time, closely associated with neurodegeneration in PSP.

A Risk Score Including Carotid Plaque Inflammation and Stenosis Severity Improves Identification of Recurrent Stroke.

Background and Purpose- In randomized trials of symptomatic carotid endarterectomy, only modest benefit occurred in patients with moderate stenosis and important subgroups experienced no benefit. Carotid plaque 18F-fluorodeoxyglucose uptake on positron emission tomography, reflecting inflammation, independently predicts recurrent stroke. We investigated if a risk score combining stenosis and plaque 18F-fluorodeoxyglucose would improve the identification of early recurrent stroke. Methods- We derived the score in a prospective cohort study of recent (<30 days) non-severe (modified Rankin Scale score ≤3) stroke/transient ischemic attack. We derived the SCAIL (symptomatic carotid atheroma inflammation lumen-stenosis) score (range, 0-5) including 18F-fluorodeoxyglucose standardized uptake values (SUVmax <2 g/mL, 0 points; SUVmax 2-2.99 g/mL, 1 point; SUVmax 3-3.99 g/mL, 2 points; SUVmax ≥4 g/mL, 3 points) and stenosis (<50%, 0 points; 50%-69%, 1 point; ≥70%, 2 points). We validated the score in an independent pooled cohort of 2 studies. In the pooled cohorts, we investigated the SCAIL score to discriminate recurrent stroke after the index stroke/transient ischemic attack, after positron emission tomography-imaging, and in mild or moderate stenosis. Results- In the derivation cohort (109 patients), recurrent stroke risk increased with increasing SCAIL score (P=0.002, C statistic 0.71 [95% CI, 0.56-0.86]). The adjusted (age, sex, smoking, hypertension, diabetes mellitus, antiplatelets, and statins) hazard ratio per 1-point SCAIL increase was 2.4 (95% CI, 1.2-4.5, P=0.01). Findings were confirmed in the validation cohort (87 patients, adjusted hazard ratio, 2.9 [95% CI, 1.9-5], P<0.001; C statistic 0.77 [95% CI, 0.67-0.87]). The SCAIL score independently predicted recurrent stroke after positron emission tomography-imaging (adjusted hazard ratio, 4.52 [95% CI, 1.58-12.93], P=0.005). Compared with stenosis severity (C statistic, 0.63 [95% CI, 0.46-0.80]), prediction of post-positron emission tomography stroke recurrence was improved with the SCAIL score (C statistic, 0.82 [95% CI, 0.66-0.97], P=0.04). Findings were confirmed in mild or moderate stenosis (adjusted hazard ratio, 2.74 [95% CI, 1.39-5.39], P=0.004). Conclusions- The SCAIL score improved the identification of early recurrent stroke. Randomized trials are needed to test if a combined stenosis-inflammation strategy improves selection for carotid revascularization where benefit is currently uncertain.

Agreement of amyloid PET and CSF biomarkers for Alzheimer's disease on Lumipulse.

OBJECTIVE: To determine the cutoffs that optimized the agreement between 18 F-Florbetapir positron emission tomography (PET) and Aß1-42, Aß1-40, tTau, pTau and their ratios measured in cerebrospinal fluid (CSF) on the LUMIPULSE G600II instrument, we quantified the levels of these four biomarkers in 94 CSF samples from participants of the Sant Pau Initiative on Neurodegeneration (SPIN cohort) using the Lumipulse G System with available 18 F-Florbetapir imaging. METHODS: Participants had mild cognitive impairment (n = 35), AD dementia (n = 12), other dementias or neurodegenerative diseases (n = 41), or were cognitively normal controls (n = 6). Levels of Aß1-42 were standardized to certified reference material. Amyloid scans were assessed visually and through automated quantification. We determined the cutoffs of CSF biomarkers that optimized their agreement with 18 F-Florbetapir PET and evaluated concordance between markers of the amyloid category. RESULTS: Aß1-42, tTau and pTau (but not Aß1-40) and the ratios with Aß1-42 had good diagnostic agreement with 18 F-Florbetapir PET. As a marker of amyloid pathology, the Aß1-42/Aß1-40 ratio had higher agreement and better correlation with amyloid PET than Aß1-42 alone. INTERPRETATION: CSF biomarkers measured with the Lumipulse G System show good agreement with amyloid imaging in a clinical setting with heterogeneous presentations of neurological disorders. Combination of Aß1-42 with Aß1-40 increases the agreement between markers of amyloid pathology.

Carotid Plaque Inflammation Imaged by 18F-Fluorodeoxyglucose Positron Emission Tomography and Risk of Early Recurrent Stroke.

Background and Purpose- Plaque inflammation contributes to stroke and coronary events. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) identifies plaque inflammation-related metabolism. Almost no prospective data exist on the relationship of carotid 18F-FDG uptake and early recurrent stroke. Methods- We did a multicenter prospective cohort study BIOVASC (Biomarkers/Imaging Vulnerable Atherosclerosis in Symptomatic Carotid disease) of patients with carotid stenosis and recent stroke/transient ischemic attack with 90-day follow-up. On coregistered carotid 18F-FDG PET/computed tomography angiography, 18F-FDG uptake was expressed as maximum standardized uptake value (SUVmax) in the axial single hottest slice. We then conducted a systematic review of similar studies and pooled unpublished individual-patient data with 2 highly similar independent studies (Dublin and Barcelona). We analyzed the association of SUVmax with all recurrent nonprocedural stroke (before and after PET) and with recurrent stroke after PET only. Results- In BIOVASC (n=109, 14 recurrent strokes), after adjustment (for age, sex, stenosis severity, antiplatelets, statins, diabetes mellitus, hypertension, and smoking), the hazard ratio for recurrent stroke per 1 g/mL SUVmax was 2.2 (CI, 1.1-4.5; P=0.025). Findings were consistent in the independent Dublin (n=52, hazard ratio, 2.2; CI, 1.1-4.3) and Barcelona studies (n=35, hazard ratio, 2.8; CI, 0.98-5.5). In the pooled cohort (n=196), 37 recurrent strokes occurred (29 before and 8 after PET). Plaque SUVmax was higher in patients with all recurrence ( P<0.0001) and post-PET recurrence ( P=0.009). The fully adjusted hazard ratio of any recurrent stroke was 2.19 (CI, 1.41-3.39; P<0.001) and for post-PET recurrent stroke was 4.57 (CI, 1.5-13.96; P=0.008). Recurrent stroke risk increased across SUVmax quartiles (log-rank P=0.003). The area under receiver operating curve for all recurrence was 0.70 (CI, 0.59-0.78) and for post-PET recurrence was 0.80 (CI, 0.64-0.96). Conclusions- Plaque inflammation-related 18F-FDG uptake independently predicted future recurrent stroke post-PET. Although further studies are needed, 18F-FDG PET may improve patient selection for carotid revascularization and suggest that anti-inflammatory agents may have benefit for poststroke vascular prevention.

Cortical atrophic-hypometabolic dissociation in the transition from premanifest to early-stage Huntington's disease.

PURPOSE: Huntington's disease (HD) is a fatal neurodegenerative disorder with no effective treatment currently available. Although the pathological hallmark of HD is massive striatal atrophy, it has been suggested that cortical deterioration may concomitantly occur and play a major role in the patient's functional independence. Our objective was to characterize cortical structural and metabolic neurodegeneration in the transition from premanifest to early-stage Huntington's disease (HD). METHODS: Using a surface-based neuroimaging approach, we compared cortical thickness and intracortical FDG-PET uptake in 19 early-symptomatic HD patients with respect to 21 premanifest HD individuals. RESULTS: Early-HD patients showed significant cortical atrophy and intracortical hypometabolism when compared to premanifest subjects (p < 0.05, corrected for multiple comparisons). However, whereas the atrophy pattern was restricted to precentral and parieto-occipital regions, a pronounced frontotemporal hypometabolism was observed. Importantly, structural changes correlated with motor and cognitive performance, and metabolic changes were associated with the presence and severity of apathy in this population, a core neuropsychiatric feature of this disorder. CONCLUSION: Our findings reveal an asynchronous neuronal loss and metabolic compromise across the cerebral cortex in early HD. Hence, the use of structural and metabolic imaging indicators to characterize disease progression in this population should take into consideration the dissociation which occurs between cortical atrophy and hypometabolism.

The impact of bilingualism on brain structure and function in Huntington's disease.

INTRODUCTION: Bilingualism exerts neuroprotective effects against neurodegeneration. In Huntington's disease (HD), the systems involved in bilingual control show early compromise, but the effect of bilingualism on the course of HD is unknown. METHODS: We addressed the impact of livelong use of bilingualism on the clinical features, brain structure and function in 30 early-mild stage HD patients. Using voxel-wise regression analysis, we explored the effect of levels of use of bilingualism on grey-matter volume (GMV) and 18F-FDG metabolism. RESULTS: Higher use of bilingualism was associated with better performance in inhibitory control and set-shifting independently of age and education and with higher GMV in the inferior frontal gyrus. 18F-FDG data revealed a significant effect on multiple fronto-temporal regions, specifically, in the dorsal anterior cingulate cortex, the anterior insula, the ventromedial orbital prefrontal cortex and the inferior frontal gyrus. These changes contributed to better inhibitory control and set-shifting and to more preserved motor and functional capacity. CONCLUSION: In HD, lifelong use of bilingualism is associated with structural and metabolic brain changes that have an impact on cognition, movement and functionality. These findings highlight the importance of stimulating cognitive and brain reserve in HD and in other neurodegenerative conditions.

Structural and metabolic brain correlates of apathy in Huntington's disease.

BACKGROUND: Apathy is the most prevalent and characteristic neuropsychiatric feature of Huntington's disease. Congruent with the main early pathological changes, apathy is primarily associated with subcortical damage in frontal-striatal circuits. However, little is known about its precise subserving mechanisms and the contribution of regions other than the basal ganglia. OBJECTIVES: We aimed to define the neural correlates of apathy in Huntington's disease based on gray matter volume and PET/CT of 18 F-fluorodeoxyglucose metabolism. METHODS: We rated the severity of apathy in 40 mild Huntington's disease participants using the Problem Behaviors Assessment for Huntington's disease. Voxelwise regression analysis was performed, controlling for effects of potential confounders, and PET/CT results were corrected for the effects of gray matter atrophy. RESULTS: Apathy was strongly associated with decreased gray matter within a spatially distributed cortico-subcortical network, with major compromise of the bilateral amygdala and temporal cortex. PET metabolism was significantly decreased in frontotemporal and parietal regions. Metabolic uptake and gray matter values in the identified clusters showed significant correlations with multiple clinical measures. CONCLUSIONS: Our findings indicate that apathy in Huntington's disease is not exclusively a consequence of basal ganglia and related frontal-executive alterations. It is subserved by a complex cortico-subcortical network where critical reward and emotional-related prefrontal, temporal, and limbic nodes contribute strongly to its severity. This highlights the contribution of damage in regions other than the basal ganglia to the clinical expression of Huntington's disease. © 2018 International Parkinson and Movement Disorder Society.