Michael Orth

Publications (3)9.01 Total impact

• Article: Rate of change in early Huntington's disease: a clinicometric analysis.

  Christina Meyer, Bernhard Landwehrmeyer, Carsten Schwenke, Adam Doble, Michael Orth, Albert C Ludolph
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  ABSTRACT: Sensitive outcome measures for patients with Huntington's disease (HD) are required for future clinical trials. Longitudinal data were collected from a 3-year study of 379 patients suffering from early HD who were not treated by antipsychotics. Progression of UHDRS item scores was evaluated by linear regression and slope, whereas correlation coefficient, standard error, and P values were estimated on the basis of the data of eight evaluations from screening to study end (36 months). For the functional assessment dimension, the proportion of "no" responses at baseline and at study end was determined. Linear progression was observed for the motor score and for all three functional measures (i.e., functional assessment score, independence assessment score, and total functional capacity score). In contrast, there was little evidence for progression of the behavioral assessment score over the study period, whereas the cognitive assessment score was intermediate. Twenty-two motor-score items showed linear progression, with a slope of >0.003. These included all chorea items, finger tapping and pronation/supination (left and right), gait, tongue protrusion, and tandem walking. Different symptom domains and individual items evolved at different rates in this group of patients suffering from early HD. It may be possible to select sensitive items to create a simplified version of the UHDRS, which would be more efficient and more sensitive for the assessment of disease progression in clinical trials and natural history studies.
  Movement Disorders 11/2011; 27(1):118-24. · 4.51 Impact Factor
• Article: What is the impact of education on Huntington's disease?

  Jose Luis López-Sendón, Ana Royuela, Patricia Trigo, Michael Orth, Herwig Lange, Ralf Reilmann, Jennifer Keylock, Hugh Rickards, Silvia Piacentini, Ferdinando Squitieri, Bernhard Landwehrmeyer, Marie-Noelle Witjes-Ane, Caroline K Jurgens, Raymund A C Roos, Victor Abraira, Justo G de Yébenes
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  ABSTRACT: Huntington's disease (HD) is a neurodegenerative disease caused by a cytosine adenosine guanine (CAG) expansion in the huntingtin gene. The length of the triplet repeat is the most important factor in determining age of onset and the severity of the disease, but substantial variability of these parameters is attributed to other factors. To investigate the relationship between the years of education and the age at onset and the severity of the phenotype in patients with HD, we applied multiple linear regression analysis to examine the impact of education on the age at onset and the severity of the clinical scores assessed by the Unified Huntington's Disease Rating Scale (UHDRS) of 891 patients with HD from the multinational observational study "Registry" conducted by the European Huntintgton's Disease Network. The model was adjusted for CAG repeat length and age at the time of assessment. Patients with lengthier education exhibited earlier estimated age at onset but less severe clinical scores (motor = -3.6, P = 0.006; cognitive = 27.0, P < 0.001; behavioral = -3.0, P < 0.001; and functional capacity = 1.1 points, P < 0.001) than those with shorter education, after controlling for age and number of CAG repeats. These differences persisted throughout all quartiles of disease severity. An earlier recognition of symptoms and manifestations among the more educated patients could explain the earlier estimated age at onset in this group. The link between better clinical UHDRS scores and higher education might reflect a beneficial effect of education or its covariates on the course of HD.
  Movement Disorders 03/2011; 26(8):1489-95. · 4.51 Impact Factor
• Article: Age-at-onset in Huntington disease.

  Michael Orth, Carsten Schwenke
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  ABSTRACT: Background: In Huntington disease, the accurate determination of age-at-onset is critical to identify modifiers and therapies that aim to delay it. Methods: Retrospective data from the European Huntington's Disease Network's REGISTRY and PREDICT-HD, a longitudinal study in prodromal huntingtin gene expansion mutation carriers. Data (age, gender, CAG repeat length, parent affected, and Unified Huntington's Disease Rating Scale motor score, total functional capacity) from at least three visits in 423 REGISTRY and 124 PREDICT-HD participants were included. Data based extrapolations of individual age-at-onset using generalized linear mixed models based on individual slopes of motor score or total functional capacity, and predictions using the Langbehn, or Ranen formula, were compared with clinicians' estimates. Results: Concordance was best for the observed age-at-onset in PREDICT-HD and the calculated onset using the PREDICT-HD UHDRS longitudinal motor scores. This was superior to the REGISTRY data. For total functional capacity, the investigator's estimate was 4 years before the data derived age-at-onset. The concordance of predictions of probability of age-at-onset is better with the observed age-at-onset in the PREDICT-HD data (difference in 25%tile -5 to 10 years) than the REGISTRY data (±20 years). Conclusions: Estimating or predicting age-at-onset in Huntington disease may be inaccurate. It can be useful to 1) add in the manifest population motor score regression derived age-at-onset as additional motor onset and 2) add total functional capacity regression derived age-at-onset for the onset of functional impact of Huntington disease when patients are in mid- to late-stage.
  PLoS currents. 01/2011; 3:RRN1258.