Neurology -- Correspondence for Shy et al., 64 (7) 1209-1214

Correspondence published:

Reply to Padua et al: Michael E Shy, Karen M. Krajewski, Mary Reilly, Richard A. Lewis (19 July 2005)

Reliability and validity of the CMT neuropathy score as a measure of disability: Luca Padua, Irene Aprile, Pietro Caliandro, Costanza Pazzaglia, Irene Commodari, and Pietro Tonali (19 July 2005)

Reply to Padua et al 19 July 2005

Michael E Shy,
Wayne State University
421 East Canfield, Detroit MI 49201,
Karen M. Krajewski, Mary Reilly, Richard A. Lewis
Send Correspondence to journal:
Re: Reply to Padua et al

m.shy{at}wayne.edu Michael E Shy, et al.

We appreciate Dr. Padua et al's comments concerning our article. [1] We agree that validated measures such as the CMTNS are potentially important outcome measures for natural history studies and clinical trials for CMT. We also agree that quality of life measurements will be important to measure in CMT patients, something that the CMTNS does not address.
However, we hope that Padua et al will agree with us that before the CMTNS or any other scoring system can be used in longitudinal studies, it will be necessary to demonstrate that the scores are capable of detecting change over time. Without this information the utility of these scoring systems must remain speculative.

Reliability and validity of the CMT neuropathy score as a measure of disability 19 July 2005

Luca Padua,
Institute of Neurology, Universita Cattolica, Roma, Fondazione Don Gnocchi
Largo Vito, 00168, Roma, Italy,
Irene Aprile, Pietro Caliandro, Costanza Pazzaglia, Irene Commodari, and Pietro Tonali
Send Correspondence to journal:
Re: Reliability and validity of the CMT neuropathy score as a measure of disability

lpadua{at}rm.unicatt.it Luca Padua, et al.

We read with great interest the article by Shy et al. [1] The authors attempt to create and validate a measure of disability for CMT patients. We agree that a validated tool to measure disability in CMT is needed. Traditional outcome assessment in neurological diseases has often been based on non-standardized and measures that are not validated. However, as suggested by the outcome research movement, we do believe that only validated measures should be used in clinical trials. [2] In addition, the disability of CMT is not easily assessed. Patients develop progressive weakness first in the legs and later in the hands. Sensory disturbances may be present. Finally, there is also clinical variability in genetically homogenous cases. [3] These disorders can cause severe disability and deteriorate the quality of life of patients.
We recently performed a prospective multi-center study in patients with CMT (granted by Telethon) by using multiple measurements. From March 2003 until September 2004, we consecutively enrolled 211 patients: 84 men (40%) and 127 women (60%), the mean age was 42.5 years(SD 15, range 8-90) in Milan (D. Pareyson), Verona (N. Rizzuto), Genova (A. Schenone), Messina (G. Vita), Catanzaro (F. Quattrone), and Rome (L. Padua). In addition to conventional clinical, pathologic, neurophysiologic and genetic measurements, we adopted validated measures to assess QoL and disability. To assess the physical disability we used two common measurements: Barthel Index (BI) [4] and an adapted form (eight-point scale) of the physical therapy portion of the Patient Evaluation Conference System (Deambulation Index, DI). [5] Performing a comparison between the results obtained from the general disability measure (BI) and from the more specific measure (DI), we observed how less sensitive the general measure was.
By using BI we observed that only few patients had severe disability (7% had a score less than 81) but through DI we observed that 60% of patients were not able to walk independently and normally. A disease-specific disability measure in clinical trials would provide even more comprehensive data and would be more sensitive to detect changes.
References
1. Shy ME, Blake J, Krajewski K, et al. Reliability and validity of the CMT neuropathy score as a measure of disability. Neurology. 2005 Apr 12;64:1209-14.
2. Tonali P, Padua L, Padua R, Sanguinetti C, Romanini E, Amadio P. Outcome research and patient-oriented in the multiperspective assessment of neurological and musculoskeletal disorders. It J Neurol Sci 20, 139-140, 1999.
3. Thomas PK, Marques W Jr, Davis MB, et al. The phenotypic manifestations of chromosome 17p11.2 duplication. Brain 1997;120:465-478.
4. Cohen ME, Marino RJ. The tools of disability outcomes research functional status measures. Arch Phys Med Reahabil 2000; 81:S21-S29.
5. Korner-Bitensky N, Mayo N, Cabot R, Becker R, Coopersmith H. Arch Phys Med Rehab 1989;70:95-99.
The authors report no conflicts of interest.