gms | German Medical Science

Objective: Patients with cervical myelopathy caused by degenerative stenosis of the cervical spinal canal suffer from loss of motor function and disturbances of sensibility. Type and degree of the symptoms vary strongly. Symptoms important for the limitation in every-day life, i.e. handicaps, include besides gait disturbance dysfunction of fine motor abilities like writing and drawing. Hitherto, only coarse description on ordinal scales of fine motor dysfuntion is given in the literature for these patients. We aim at realizing an objective measurement of fine motor dysfunction by performing an analysis of kinematic parameters using a digitizing graphic tablet.

Method: 28 patients with cervical myelopathy were administered to a measurement of standardized movement tasks with a sensor-equipped pencil on a digitizing graphic tablet including drawing of circles (task 1), writing of the German sentence “Ein Ball rollt ins Tor“ (task 2), and writing a row of the letter “a“ (task 3). Kinematic parameters for automation (mean number of changes of velocity per stroke, NCV), speed (frequency of strokes, F) and writing or drawing pressure (P) of movements were calculated using the software CSWIN.

Results: Movements of 28 patients (7 female and 21 male) with a mean age of 63 ys (SD: 11.4, age span: 39 – 80 y) were analyzed. 25 patients were right handed, 3 left handed. Maximum of the pathologic signal of the myelon was on the level of C3/4 or higher in 5 patients, of C4/5 in 11 patients, of C5/6 in 6 patients, and of C7-TH1 in 6 patients. Patients showed significantly lower speed in all tasks compared to healthy subjects (F of task 1: p = 0.01, task 2: p < 0.001, task 3: p < 0.001), significantly impaired automation (NCV of task 2: p = 0.03 and task 3: p < 0.001) and significantly elevated pressure in task 3 (P of task 3: p = 0.02).

Conclusions: Analysis of kinematic parameters of writing and drawing movements in patients with cervical myelopathy is capable to detect and objectify the type and degree of fine motor dysfunction and is easily available. Therefore, this analysis is a powerful tool to monitor fine motor dysfunction of patients with cervical myelopathy before, during, and after therapy to detect therapeutic effects. Longitudinal studies and correlational studies including electrophysiologic and magnetic resonance measurements are warranted to improve our understanding of the manifestation and process of cervical myelopathy and clinical significance of these diagnostic tools and therapeutic efforts.