T. Schmitz-Hübsch

Bio: T. Schmitz-Hübsch is an academic researcher from University of Bonn. The author has contributed to research in topics: Spinocerebellar ataxia & Medicine. The author has an hindex of 22, co-authored 31 publications receiving 3030 citations. Previous affiliations of T. Schmitz-Hübsch include University Hospital Bonn.

Scale for the assessment and rating of ataxia: development of a new clinical scale.

Abstract: OBJECTIVE: To develop a reliable and valid clinical scale measuring the severity of ataxia. METHODS: The authors devised the Scale for the Assessment and Rating of Ataxia (SARA) and tested it in two trials of 167 and 119 patients with spinocerebellar ataxia. RESULTS: The mean time to administer SARA in patients was 14.2 +/- 7.5 minutes (range 5 to 40). Interrater reliability was high, with an intraclass coefficient (ICC) of 0.98. Test-retest reliability was high with an ICC of 0.90. Internal consistency was high as indicated by Cronbach's alpha of 0.94. Factorial analysis revealed that the rating results were determined by a single factor. SARA ratings showed a linear relation to global assessments using a visual analogue scale, suggesting linearity of the scale (p < 0.0001, r(2) = 0.98). SARA score increased with the disease stage (p < 0.001) and was closely correlated with the Barthel Index (r = -0.80, p < 0.001) and part IV (functional assessment) of the Unified Huntington's Disease Rating Scale (UHDRS-IV) (r = -0.89, p < 0.0001), whereas it had only a weak correlation with disease duration (r = 0.34, p < 0.0002). CONCLUSIONS: The Scale for the Assessment and Rating of Ataxia is a reliable and valid measure of ataxia, making it an appropriate primary outcome measure for clinical trials.

Spinocerebellar ataxia types 1, 2, 3, and 6 Disease severity and nonataxia symptoms

Abstract: Objective: To identify factors that determine disease severity and clinical phenotype of the most common spinocerebellar ataxias (SCAs), we studied 526 patients with SCA1, SCA2, SCA3. or SCA6. Methods: To measure the severity of ataxia we used the Scale for the Assessment and Rating of Ataxia (SARA). In addition, nonataxia symptoms were assessed with the Inventory of Non-Ataxia Symptoms (INAS). The INAS count denotes the number of nonataxia symptoms in each patient. Results: An analysis of covariance with SARA score as dependent variable and repeat lengths of the expanded and normal allele, age at onset, and disease duration as independent variables led to multivariate models that explained 60.4% of the SARA score variance in SCA1, 45.4% in SCA2, 46.8% in SCA3, and 33.7% in SCA6. In SCA1, SCA2, and SCA3, SARA was mainly determined by repeat length of the expanded allele, age at onset, and disease duration. The only factors determining the SARA score in SCA6 were age at onset and disease duration. The INAS count was 5.0 ± 2.3 in SCA1, 4.6 ± 2.2 in SCA2, 5.2 ± 2.5 in SCA3, and 2.0 ± 1.7 in SCA6. In SCA1, SCA2, and SCA3, SARA score and disease duration were the strongest predictors of the INAS count. In SCA6, only age at onset and disease duration had an effect on the INAS count. Conclusions: Our study suggests that spinocerebellar ataxia (SCA) 1, SCA2, and SCA3 share a number of common biologic properties, whereas SCA6 is distinct in that its phenotype is more determined by age than by disease-related factors.

Scale for the Assessment and Rating of Ataxia (SARA)

Abstract: The Scale for the Assessment and Rating of Ataxia (SARA) was published in 2006 as a standardized clinical assessment of ataxia severity. SARA had favorable metric properties, validity, and high reliability in groups of patients with spinocerebellar ataxias (SCAs) and other chronic ataxia disorders.

The natural history of spinocerebellar ataxia type 1, 2, 3, and 6: a 2-year follow-up study

Abstract: Objective: To obtain quantitative data on the progression of the most common spinocerebellar ataxias (SCAs) and identify factors that influence their progression, we initiated the EUROSCA natural history study, a multicentric longitudinal cohort study of 526 patients with SCA1, SCA2, SCA3, or SCA6. We report the results of the 1- and 2-year follow-up visits. Methods: As the primary outcome measure we used the Scale for the Assessment and Rating of Ataxia (SARA, 0–40), and as a secondary measure the Inventory of Non-Ataxia Symptoms (INAS, 0–16) count. Results: The annual increase of the SARA score was greatest in SCA1 (2.18 ± 0.17, mean ± SE) followed by SCA3 (1.61 ± 0.12) and SCA2 (1.40 ± 0.11). SARA progression in SCA6 was slowest and nonlinear (first year: 0.35 ± 0.34, second year: 1.44 ± 0.34). Analysis of the INAS count yielded similar results. Larger expanded repeats and earlier age at onset were associated with faster SARA progression in SCA1 and SCA2. In SCA1, repeat length of the expanded allele had a similar effect on INAS progression. In SCA3, SARA progression was influenced by the disease duration at inclusion, and INAS progression was faster in females. Conclusions: Our study gives a comprehensive quantitative account of disease progression in SCA1, SCA2, SCA3, and SCA6 and identifies factors that specifically affect disease progression.

Reliability and validity of the scale for the assessment and rating of ataxia: A study in 64 ataxia patients

Abstract: The objective of this study was to test the reliability and validity of the Scale for the Assessment and Rating of Ataxia (SARA) in ataxia patients not suffering from autosomal dominant spinocerebellar ataxia (SCA). To this end, 64 patients with various ataxia disorders or stable cerebellar lesions were rated independently by two investigators. In addition to SARA, the following assessment instruments were applied: ataxia disease stage, Barthel index and part IV (functional assessment) of the Unified Huntington's Disease Rating scale (UHDRS-IV). Eighteen patients were rated twice. Inter-rater and intrarater reliability were very high with ICCs of 0.98 and 0.99. Internal consistency was high indicated by Cronbach's alpha of 0.97. Factorial analysis revealed that the rating results were mainly determined by one major factor with an eigenvalue of 6.34 which explained 52.8% of the variance. SARA score increased with disease stage (P<0.0001) and was closely correlated with Barthel index (r=-0.63, P<0.0001) and UHDRS-IV (r=-0.62, P<0.0001), but only weakly correlated with disease duration (r=0.44, P<0.001). The results suggest that SARA is a reliable and valid measure of ataxia in non-SCA ataxia patients.

Parkinson's disease: from monogenic forms to genetic susceptibility factors

Abstract: Research in Parkinson's disease (PD) genetics has been extremely prolific over the past decade. More than 13 loci and 9 genes have been identified, but their implication in PD is not always certain. Point mutations, duplications and triplications in the alpha-synuclein (SNCA) gene cause a rare dominant form of PD in familial and sporadic cases. Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are a more frequent cause of autosomal dominant PD, particularly in certain ethnic groups. Loss-of-function mutations in Parkin, PINK1, DJ-1 and ATP13A2 cause autosomal recessive parkinsonism with early-onset. Identification of other Mendelian forms of PD will be a main challenge for the next decade. In addition, susceptibility variants that contribute to PD have been identified in several populations, such as polymorphisms in the SNCA, LRRK2 genes and heterozygous mutations in the beta-glucocerebrosidase (GBA) gene. Genome-wide associations and re-sequencing projects, together with gene-environment interaction studies, are expected to further define the causal role of genetic determinants in the pathogenesis of PD, and improve prevention and treatment.

Epidemiology and etiology of Parkinson’s disease: a review of the evidence

Abstract: The etiology of Parkinson’s disease (PD) is not well understood but likely to involve both genetic and environmental factors. Incidence and prevalence estimates vary to a large extent—at least partly due to methodological differences between studies—but are consistently higher in men than in women. Several genes that cause familial as well as sporadic PD have been identified and familial aggregation studies support a genetic component. Despite a vast literature on lifestyle and environmental possible risk or protection factors, consistent findings are few. There is compelling evidence for protective effects of smoking and coffee, but the biologic mechanisms for these possibly causal relations are poorly understood. Uric acid also seems to be associated with lower PD risk. Evidence that one or several pesticides increase PD risk is suggestive but further research is needed to identify specific compounds that may play a causal role. Evidence is limited on the role of metals, other chemicals and magnetic fields. Important methodological limitations include crude classification of exposure, low frequency and intensity of exposure, inadequate sample size, potential for confounding, retrospective study designs and lack of consistent diagnostic criteria for PD. Studies that assessed possible shared etiological components between PD and other diseases show that REM sleep behavior disorder and mental illness increase PD risk and that PD patients have lower cancer risk, but methodological concerns exist. Future epidemiologic studies of PD should be large, include detailed quantifications of exposure, and collect information on environmental exposures as well as genetic polymorphisms.

The impact of non-motor symptoms on health-related quality of life of patients with Parkinson's disease.

Abstract: Background: Non-motor symptoms are detrimental to health-related quality of life (HRQoL) of Parkinson's disease patients. In this study, the Non-Motor Symptoms Scale (NMSS) was used to assess the impact of the non-motor symptoms on HRQoL of Parkinson's disease patients. Methods: In a multicenter, international, cross sectional study on 411 Parkinson's disease patients, the NMSS was applied along with clinical (Hoehn and Yahr staging and SCOPA-Motor) and HRQoL measures (PDQ-39, and EQ-5D). Prevalence of non-motor symptoms was determined also through the NMSS. The association of NMSS and SCOPA-Motor with HRQoL measures and the differences in HRQoL scores between patients with and without non-motor symptoms in each NMSS domain were estimated by non-parametric statistics. Predictors of HRQoL were sought through multiple linear regression analyses. Results: Nocturia (68.4% of the sample), fatigue (65.9%), and dribbling saliva (56.7%), were the most frequent complaints. Total NMSS score: (1) showed a higher correlation coefficient (rS = 0.70) with the PDQ-39 Summary Index (SI) than SCOPA-Motor (rS = 0.58); (2) showed high-moderate correlation (rS = 0.60 − 0.38) with all PDQ-39 domains; and (3) was the best predictor of HRQoL as measured by the PDQ-39 SI. For each NMSS domain, patients with symptoms had significantly worse HRQoL scores than patients without symptoms. Discussion: To our knowledge, this is the first study to determine in a holistic manner the impact of the non-motor symptoms on HRQoL of Parkinson's disease patients. The results show that non-motor symptoms have, as a whole, a greater impact on HRQoL than motor symptoms and non-motor symptoms progression contributes importantly to HRQoL decline in patients with Parkinson's disease. © 2011 Movement Disorder Society

Dye Sensitizers for Photodynamic Therapy.

Abstract: Photofrin® was first approved in the 1990s as a sensitizer for use in treating cancer via photodynamic therapy (PDT). Since then a wide variety of dye sensitizers have been developed and a few have been approved for PDT treatment of skin and organ cancers and skin diseases such as acne vulgaris. Porphyrinoid derivatives and precursors have been the most successful in producing requisite singlet oxygen, with Photofrin® still remaining the most efficient sensitizer (quantum yield = 0.89) and having broad food and drug administration (FDA) approval for treatment of multiple cancer types. Other porphyrinoid compounds that have received approval from US FDA and regulatory authorities in other countries include benzoporphyrin derivative monoacid ring A (BPD-MA), meta-tetra(hydroxyphenyl)chlorin (m-THPC), N-aspartyl chlorin e6 (NPe6), and precursors to endogenous protoporphyrin IX (PpIX): 1,5-aminolevulinic acid (ALA), methyl aminolevulinate (MAL), hexaminolevulinate (HAL). Although no non-porphyrin sensitizer has been approved for PDT applications, a small number of anthraquinone, phenothiazine, xanthene, cyanine, and curcuminoid sensitizers are under consideration and some are being evaluated in clinical trials. This review focuses on the nature of PDT, dye sensitizers that have been approved for use in PDT, and compounds that have entered or completed clinical trials as PDT sensitizers.

G51D α-synuclein mutation causes a novel parkinsonian-pyramidal syndrome.

Abstract: To date, 3 rare missense mutations in the SNCA (α-synuclein) gene and the more frequent duplications or triplications of the wild-type gene are known to cause a broad array of clinical and pathological symptoms in familial Parkinson disease (PD). Here, we describe a French family with a parkinsonian-pyramidal syndrome harboring a novel heterozygous SNCA mutation. Whole exome sequencing of DNA from 3 patients in a 3-generation pedigree was used to identify a new PD-associated mutation in SNCA. Clinical and pathological features of the patients were analyzed. The cytotoxic effects of the mutant and wild-type proteins were assessed by analytical ultracentrifugation, thioflavin T binding, transmission electron microscopy, cell viability assay, and caspase-3 activation. We identified a novel SNCA G51D (c.152 G>A) mutation that cosegregated with the disease and was absent from controls. G51D was associated with an unusual PD phenotype characterized by early disease onset, moderate response to levodopa, rapid progression leading to loss of autonomy and death within a few years, marked pyramidal signs including bilateral extensor plantar reflexes, occasionally spasticity, and frequently psychiatric symptoms. Pathological lesions predominated in the basal ganglia and the pyramidal tracts and included fine, diffuse cytoplasmic inclusions containing phospho-α-synuclein in superficial layers of the cerebral cortex, including the entorhinal cortex. Functional studies showed that G51D α-synuclein oligomerizes more slowly and its fibrils are more toxic than those of the wild-type protein. We have identified a novel SNCA G51D mutation that causes a form of PD with unusual clinical, neuropathological, and biochemical features.