Sofia Tsouli

Assessment of Tremor Activity in the Parkinson’s Disease Using a Set of Wearable Sensors

Tremor is the most common motor disorder of Parkinsons disease (PD) and consequently its detection plays a crucial role in the management and treatment of PD patients. The current diagnosis procedure is based on subject-dependent clinical assessment, which has a difficulty in capturing subtle tremor features. In this paper, an automated method for both resting and action/postural tremor assessment is proposed using a set of accelerometers mounted on different patients body segments. The estimation of tremor type (resting/action postural) and severity is based on features extracted from the acquired signals and hidden Markov models. The method is evaluated using data collected from 23 subjects (18 PD patients and 5 control subjects). The obtained results verified that the proposed method successfully: 1) quantifies tremor severity with 87 % accuracy, 2) discriminates resting from postural tremor, and 3) discriminates tremor from other Parkinsonian motor symptoms during daily activities.

Pathogenesis, detection and treatment of Achilles tendon xanthomas

Tendon xanthomatosis often accompanies familial hypercholesterolaemia, but it can also occur in other pathologic states. Achilles tendons are the most common sites of tendon xanthomas. Low‐density lipoprotein (LDL) derived from the circulation accumulates into tendons. The next steps leading to the formation of Achilles tendon xanthomas (ATX) are the transformation of LDL into oxidized LDL (oxLDL) and the active uptake of oxLDL by macrophages within the tendons. Although physical examination may reveal Achilles tendon xanthomas (ATX), there are several imaging methods for their detection. It is worth mentioning that ultrasonography is the method of choice in everyday clinical practice. Although several treatments for Achilles tendon xanthomas (ATX) have been proposed (LDL apheresis, statins, etc.), they target mostly in the treatment of the basic metabolic disorder of lipid metabolism, which is the main cause of these lesions. In this review we describe the formation, detection, differential diagnosis and treatment of ATX as well as the relationship between tendon xanthomas and atheroma.

Regression of Achilles tendon thickness after statin treatment in patients with familial hypercholesterolemia: An ultrasonographic study

OBJECTIVE Achilles tendon xanthomas (ATX) have been associated with increased cardiovascular risk in patients with familial hypercholesterolemia (FH). The aim of this study was to evaluate clinical and ultrasonographic changes of ATX in patients with FH under statin treatment. METHODS Achilles tendon thickness (ATT) and echostructure were studied by ultrasonography (US) in 80 unrelated heterozygous FH patients and in 80 age- and sex-matched controls. For ATT measurements the anterioposterior diameter (mm) of the Achilles tendon was measured on sagittal scans. Patients were treated with atorvastatin (mean dose 20+/-10mg/day) and a follow-up examination was performed 12 months later. RESULTS Clinical examination revealed xanthomas in 15 patients. On US normal fibrillar echostructure (grade 1) of the Achilles tendon (AT) was observed in 42 patients, abnormal echostructure with diffuse heterogeneous echo pattern (grade 2) in 30 patients and focal hypoechoic lesions (grade 3) in 8 patients. At baseline, ATT of all patients (5.23+/-0.91 mm) was significantly larger compared with controls (4.20+/-0.70 mm) (p<0.05). Patients with grades 2 (5.20+/-0.60 mm) and 3 (6.98+/-1.07 mm) had significantly larger ATT than those with grade 1 (4.90+/-0.55 mm), p<0.05. Patients with grade 1 showed significant reduction in ATT after statin treatment (from 4.90+/-0.55 mm to 4.50+/-0.43 mm, p<0.01). In patients with grades 2 and 3 abnormal echostructure remained unchanged and no significant reduction in ATT was observed. CONCLUSION Statin treatment reduces ATT in FH patients with normal AT echostructure. Ultrasound detects AT structural involvement and is useful in the monitoring of response to treatment.

Lack of Association Between Carotid Intima-Media Thickness and PAF-Acetylhydrolase Mass and Activity in Patients with Primary Hyperlipidemia:

Carotid intima media thickness (IMT), represents an important clinical indicator of early atherosclerosis. Human plasma platelet-activating factor acetylhydrolase (PAF-AH) is an enzyme primarily associated with low-density lipoprotein (LDL) while a small proportion of enzymatic activity is also associated with high-density lipoprotein (HDL). Plasma paraoxonase 1 (PON1) is an esterase exclusively associated with HDL. The authors investigated the possible relationship between carotid IMT and the plasma levels of PAF-AH mass and activity as well as the PON1 activity in hyperlipidemic patients. One hundred unrelated patients with primary hyperlipidemia and 67 age- and sex-matched normolipidemic apparently healthy volunteers participated in the study. The PAF-AH activity in total plasma and in HDL-rich plasma (HDL-PAF-AH activity), the plasma PAF-AH mass, and the serum PON1 activities toward paraoxon and phenyl acetate were determined. The plasma PAF-AH mass and activity were higher in hyperlipidemic patients compared to controls, whereas the HDL-PAF-AH activity, as well as the serum PON1 activities were not significantly different between the studied groups. When hyperlipidemic patients were divided into 2 subgroups according to their IMT values (IMT <0.7 mm and IMT ≥0.7 mm) patients with IMT ≥0.7 mm had significantly higher age, and serum triglyceride concentrations, whereas no difference was found in the plasma PAF-AH mass and activity as well as in the HDL-PAF-AH activity between the 2 studied subgroups. The same phenomenon was observed for serum PON1 activities. In a multivariate analysis, only the age was significantly correlated with IMT values (p<0.05). Neither the total plasma PAF-AH mass and activity nor the HDL-PAF-AH activity are associated with early carotid atherosclerosis.

Autoantibody titers against OxLDL are correlated with Achilles tendon thickness in patients with familial hypercholesterolemia

Achilles tendon xanthomas are associated with increased cardiovascular risk in patients with familial hypercholesterolemia (FH). Oxidized low density lipoprotein (OxLDL), the antibodies against OxLDL, and the LDL-associated phospholipase A2 (Lp-PLA2) may play important roles in atherogenesis. We investigated the possible association between plasma levels of OxLDL, Lp-PLA2 activity, and autoantibody titers against various types of mildly OxLDL with Achilles tendon thickness (ATT). ATT was determined by sonography in 80 unrelated heterozygous FH patients. Three different types of mildly OxLDL were prepared: OxLDLL, OxLDLP, and OxLDLD, at the end of the lag, propagation, and decomposition phases of oxidation, respectively. Similar types of OxLDL were also prepared after inactivation of the LDL-associated Lp-PLA2. These types were denoted OxLDL(−)L, OxLDL(−)P, and OxLDL(−)D. FH patients exhibited significantly higher plasma OxLDL levels and serum IgG titers against OxLDLP and OxLDLD compared with 40 normolipidemic apparently healthy controls. ATT values were positively correlated with autoantibody titers against OxLDLP and OxLDLD; however, in multiple regression analysis, ATT was independently associated only with the autoantibody titers against OxLDLD. We conclude that the IgG autoantibody titers against OxLDLD but not OxLDL or Lp-PLA2 may play an important role in the pathogenesis of Achilles tendon xanthomas in FH patients.

Combined Treatment With Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers: A Review of the Current Evidence

Several studies have shown that angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are useful in the treatment of hypertension, cardiovascular disease, chronic heart failure, and some types of nephropathy. In this context, dual renin-angiotensin system blockade with both angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers may be more effective than treatment with each agent alone. Many clinical trials have demonstrated the beneficial effect of this combined treatment on proteinuria, hypertension, heart failure, and cardiovascular events. Moreover, these studies demonstrated that dual renin-angiotensin system blockade is generally safe and well tolerated. Long-term studies are under way to confirm these effects and also investigate the effectiveness of dual reninangiotensin system blockade on cerebrovascular disease and prevention of type 2 diabetes mellitus. These studies are expected to define the optimal use of combination treatment in everyday clinical practice. This review considers the most important clinical trials that evaluated the effect of dual renin-angiotensin system blockade on blood pressure, heart failure, and renal function.

Voxel‐Based Morphometry and Voxel‐Based Relaxometry in Parkinsonian Variant of Multiple System Atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative disorder divided into a parkinsonian (MSA‐P) and a cerebellar variant. The purpose of this study was to assess regional brain atrophy and iron content using Voxel‐based morphometry (VBM) and Voxel‐based relaxometry (VBR) respectively, in MSA‐P.

Should a statin be prescribed to every patient with heart failure

Chronic heart failure (HF) represents an emerging epidemic since its prevalence is continuously increasing despite advances in treatment. Many recent clinical studies have clearly demonstrated that statin therapy is associated with improved outcomes in HF irrespective of aetiology (ischaemic or not) or baseline cholesterol levels. Indeed, most of the conducted large statin trials and trials in HF have demonstrated a positive effect of statins in HF patients. Furthermore, the use of statins in HF seems to be safe as none of the recent trials has resulted in worse outcomes for HF patients treated with statins. Potential mechanisms through which statins could benefit the failing myocardium include non-sterol effects of statins, as well as effects on nitric oxide and endothelial function, inflammation and adhesion molecules, apoptosis and myocardial remodelling and neurohormonal activation. This review discusses the pathophysiological basis of statin effects on HF and focuses on clinical data for the benefit from statin use in this setting. Until today there are no official recommendations in both the American and the European guidelines regarding the use of statins in HF patients, as the available data come from small observational or larger but retrospective, non-randomised studies. Therefore, HF patients should be treated according to current lipid guidelines. Large randomised clinical trials are underway and will further delineate the role of statin therapy in HF patients. Until more data are available, we could not recommend statin use to every patient with HF irrespective of HF aetiology and baseline cholesterol levels.

PERFORM: A platform for monitoring and management of chronic neurodegenerative diseases: The Parkinson and Amyotrophic Lateral Sclerosis case

In this work we present a system for the monitoring and management of neurodegenerative diseases, such as the Parkinsons Disease (PD) and Amyotrophic Lateral Sclerosis (ALS). The purpose of the system is to monitor patients motor symptoms, and assist the clinician in the evaluation of both the current patient status and the disease progression. The system progresses one step further and suggests appropriate patient treatment changes, based on previously stored or accumulated medical knowledge. In this work, we focus on the description of the wearable platforms used to monitor the patient motor status at the patients environment.

On Assessing Motor Disorders in Parkinson's Disease

In this paper we propose an automated method for assessing motor symptoms in Parkinson’s disease. Levodopa-induced dyskinesia (LID) and Freezing of Gait (FoG) are detected based on the analysis of signals recorded from wearable devices, i.e. accelerometers and gyroscopes, which are placed on certain positions on the patient’s body. The signals are initially pre-processed and then analyzed, using a moving window, in order to extract features from them. These features are used for LID and FoG assessment. Two classification techniques are employed, decision trees and random forests. The method has been evaluated using a group of patients and the obtained results indicate high classification ability, being 96.11% classification accuracy for FoG detection and 92.59% for LID severity assessment.