Abstract Compensatory mechanisms in Parkinson’s disease are defined as the changes that the brain uses to adapt to neurodegeneration and progressive dopamine reduction. Motor compensation in early ...Parkinson’s disease could, in part, be responsible for a unilateral onset of clinical motor signs despite the presence of bilateral nigrostriatal degeneration. Although several mechanisms have been proposed for compensatory adaptations in Parkinson’s disease, the underlying pathophysiology is unclear. Here, we investigate motor compensation in Parkinson’s disease by investigating the relationship between clinical signs, dopamine transporter imaging data and neurophysiological measures of the primary motor cortex (M1), using transcranial magnetic stimulation in presymptomatic and symptomatic hemispheres of patients. In this cross-sectional, multicentre study, we screened 82 individuals with Parkinson’s disease. Patients were evaluated clinically in their medication OFF state using standardized scales. Sixteen Parkinson’s disease patients with bilateral dopamine transporter deficit in the putamina but unilateral symptoms were included. Twenty-eight sex- and age-matched healthy controls were also investigated. In all participants, we tested cortical excitability using single- and paired-pulse techniques, interhemispheric inhibition and cortical plasticity with paired associative stimulation. Data were analysed with ANOVAs, multiple linear regression and logistic regression models. Individual coefficients of motor compensation were defined in patients based on clinical and imaging data, i.e. the motor compensation coefficient. The motor compensation coefficient includes an asymmetry score to balance motor and dopamine transporter data between the two hemispheres, in addition to a hemispheric ratio accounting for the relative mismatch between the magnitude of motor signs and dopaminergic deficit. In patients, corticospinal excitability and plasticity were higher in the presymptomatic compared with the symptomatic M1. Also, interhemispheric inhibition from the presymptomatic to the symptomatic M1 was reduced. Lower putamen binding was associated with higher plasticity and reduced interhemispheric inhibition in the presymptomatic hemisphere. The motor compensation coefficient distinguished the presymptomatic from the symptomatic hemisphere. Finally, in the presymptomatic hemisphere, a higher motor compensation coefficient was associated with lower corticospinal excitability and interhemispheric inhibition and with higher plasticity. In conclusion, the present study suggests that motor compensation involves M1–striatal networks and intercortical connections becoming more effective with progressive loss of dopaminergic terminals in the putamen. The balance between these motor networks seems to be driven by cortical plasticity.
We report a Dystonia-Deafness syndrome patient treated by pallidal Deep Brain Stimulation with significant long-term benefits. Our study expands and confirms the complex phenotypic spectrum of ACTB ...gene-related disorders and supports the effectiveness of pallidal stimulation on motor outcomes and quality of life in dystonia due to ACTB p.Arg183Trp heterozygosity.
•Dystonia-Deafness syndrome (DDS) can result from several known or unknown molecular or genetic causes.•ACTB (cytoplasmic beta actin) gene mutations can produce complex phenotypic spectra, like DDS and late-onset parkinsonism.•Pallidal Deep Brain Stimulation may produce a significant long-term benefit on dystonic signs of DDS.
Brain iron homeostasis is disrupted in neurodegeneration and areas of iron overload partially overlap with regions of amyloid and tau burden in Alzheimer's disease (AD). Previous studies demonstrated ...alterations in brain iron accumulation in AD using quantitative susceptibility mapping (QSM).
Here, we investigate brain alterations of QSM values in AD and non-AD patients as compared to healthy controls (HC) in the superior temporal sulcus and its banks (BANKSSTS), one of the top AD-affected regions.
Thirty-four patients who underwent brain MRI including a multi-echo gradient-echo sequence were subdivided into AD (n = 19) and non-AD (n = 15) groups according to their clinical profile, CSF (Aβ42/40) and/or amyloid-PET status. Ten HC were also included. QSM values were extracted from left and right BANKSSTS and compared among groups. Correlation and binomial regression analyses between QSM values and CSF-AD biomarkers were conducted.
QSM in left BANKSSTS was significantly different among groups (p = 0.003, H = 11.40), being higher in AD. QSM values in left BANKSSTS were correlated with Aβ42 (rho -0.55, p = 0.005), Aβ42/40 (rho -0.66, p < 0.001), pTau (rho 0.63, p < 0.001), tTau (rho 0.56, p = 0.005), tTau/Aβ42 (rho 0.68, p < 0.001) and pTau/Aβ42 (rho 0.71, p < 0.001). No correlations between QSM values and amyloid-PET SUVR in the left BANKSSTS were found. QSM values in left BANKSSTS showed good accuracy in discriminating AD (AUC = 0.80, CI95 % 0.66-0.93). Higher QSM values were independent predictors of Aβ42 (B = 0.63, p = 0.032), Aβ42/40 (B = 0.81, p = 0.028), pTau (B = 0.96, p = 0.046), tTau (B = 0.55, p = 0.027), and tTau/Aβ42 (B = 1.13, p = 0.042) positivity.
Our preliminary data support the potential role of increased QSM values in the left BANKSSTS as an auxiliary imaging biomarker in AD diagnosis.
Background
Mutations in ANO3 are a rare cause of autosomal dominant isolated or combined dystonia, mainly presenting in adulthood.
Cases
We extensively characterize a new, large ANO3 family with six ...affected carriers. The proband is a young girl who had suffered from tremor and painful dystonic movements in her right arm since the age of 11 years. She later developed a diffuse dystonic tremor and mild extrapyramidal signs (ie, rigidity and hypodiadochokinesis) in her right arm. She also suffered from psychomotor delay and learning difficulties. Repeated structural and functional neuroimaging were unremarkable. A dystonic tremor was also present in her two sisters. Her paternal aunt, father, and a third older sister presented episodic postural tremor in the arms. The father and one sister also presented learning difficulties. The heterozygous p.G6V variant in ANO3 was identified in all affected subjects.
Literature review
Stratification by age at onset divided ANO3 cases into two major groups, where younger patients displayed a more severe phenotype, probably due to variants near the scrambling domain.
Conclusions
We describe the phenotype of a new ANO3 family and highlight the need for functional studies to explore the impact of ANO3 variants on its phospholipid scrambling activity.
ABSTRACTF-choline PET/CT was performed for suspected prostate cancer relapse in a 67-year-old man with hip pain and a rapid rise in prostate-specific antigen values (1.1 ng/mL). PET imaging showed an ...area of increased F-choline bone uptake in the right ischium. Coregistered CT images showed a lytic bone lesion. The infrequent CT appearance of a possible prostate carcinoma metastasis led to additional laboratory testing that showed a monoclonal γ-peak and to subsequent biopsy, which revealed a solitary plasmocytoma.
Purpose
To characterise tissue sites of immune activation and HIV replication we performed FDG-PET in ART-treated and ART-naive HIV-infected individuals. Specific aims were to establish whether ...HIV-infected patients can be differentiated on the basis of the detection of specific locations of viral replication, even in the presence of an apparently optimal immunovirological response to ART, and whether these FDG-PET findings can be related to immunovirological variables and AIDS history status.
Patients and methods
Patients were divided into five groups as follows: subgroup A1 (full responders,
n
= 8): current ART treatment, CD4+ T lymphocytes >500/mL, viral load <50 copies/mL; subgroup A2 (full responders,
n
= 5): same criteria as A-1, but with a previous history of AIDS; subgroup A3 (immunological non responders,
n
= 5): current ART treatment, viral load <50 copies/mL, low CD4+ T lymphocytes (<200/mL); group B (virological non responders,
n
= 2): current ART treatment, CD4+ T lymphocytes around 500/mL, viral load >50,000 copies/mL; group C (ART-naïve,
n
= 5): no current or previous ART treatment, increased viral load.
Results
PET images revealed different patterns of FDG uptake. All ART-treated patients with either suppressed (<50 copies/mL; Group A) or high viremia (group B) showed a normal pattern of FDG uptake. On the contrary, the ART-naïve subjects with high viraemia (group C) displayed multiple foci of increased glucose metabolism in the lymph nodes. In the ART-naïve subjects, FDG uptake, apparently related to viraemia level, was observed in the upper torso mainly in the axillary nodes bilaterally in patients with viraemia below 100,000 copies/mL; in those with viraemia higher than 100,000 copies/mL, FDG uptake was also observed in the inguinal lymph nodes.
Conclusions
The emergence, in our study, of a correlation between the percentage of CD8+/CD38+/RO+ T cells (well established markers of progression to AIDS independently of CD4+ T lymphocytes) and positive FDG-PET in ART-naive patients is a novel finding that seems to confer prognostic value on FDG uptake. FDG uptake is strongly associated with response to ART independently of a previous AIDS diagnosis. Notably, no differences were observed between ART-treated subjects classed as immunological responders and those classed as non responders. Data herewith indicate that FDG uptake and immunological variables are unrelated when ART is being administered. This is evidence of the complementarity of immunological and FDG measures. FDG uptake is a sensitive marker of disease state and its relation with CD8+/CD38+/CD45RO+ T cells indicates that it can be considered a marker of disease status. The lack of a correlation between FDG uptake and immunological variables in patients under ART warrants further investigation.
Radionuclide therapy using iodine-131 is widely employed in the work-up of differentiated thyroid carcinoma. After a brief introduction on physical and dosimetry characteristics of radioactive ...iodine, this paper suggests state of the arts protocol for the ablation of thyroid remnants and for the treatment of metastatic disease. Diagnostic applications of Nuclear Medicine in these tumors are critically evaluated as well, from the use of iodine-131 whole-body scan to 18F-FDG PET and other new diagnostic tools. Finally, a brief description of new radionuclide treatments is reported
