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. The resulting handicaps include gait disturbance and fine motor dysfunction. Previous studies determined outcome after decompression mainly using subjective methods like questionnaires. Changes of fine motor dysfunction were not assessed thoroughly and objectively yet. We aimed at realizing an objective measurement of regeneration of fine motor dysfunction and gait disorder using advanced kinematic analysis tools.

Method: 22 patients with cervical myelopathy underwent specific standardized neurologic and MR assessment before surgery and 6 months after. The assessment included an advanced analysis of fine motor function using a digitizing graphic tablet (CSWIN). Furthermore, speed of gait, symptoms of gait ataxia (International Cooperative Ataxia Rating Scale, ICARS), Nurick score, and Visual Analogue Scale (VAS) were quantified. The extent of pathologic signal in MRI was determined on T2-weighted sagittal slices.

Results: 22 patients (6 female and 16 male) with a mean age of 60.2 ys (SD: 11.3, age span: 39–74 y) completed pre- and post-surgical assessment after 6 months. Kinematic parameters improved significantly for speed and automation in the task of writing continuously the letter “a” (Frequency of strokes: p=0.05, peak velocity: p<0.001, number of inversions: p=0.03, Wilcoxon test). In the task writing a sentence peak velocity was significantly higher. No significant changes were noted in the simple task of drawing a circle. Length of pathologic signal measured on the T2-weighted MRI decreased significantly (p=0.001). Furthermore, speed of gait (p=0.011), the gait subscore of ICARS (p=0.014) and VAS (p=0.008) improved significantly after the regeneration period, while Nurick score only trended to improve (p=0.058).

Conclusions: The present study objectifies and quantifies the potential of regeneration after decompression: Especially, the performance of complex fine motor challenges regenerated, while the execution of simple repetitive movement patterns remained on the same level. Fine motor dysfunction, gait disturbance and pain improved post-operatively, corresponding to a diminished pathologic signal in T2-weighted MRI. Thus, this study provides specific evidence to the occurrence of significant regeneration of motor dysfunction after decompression in patients with cervical myelopathy.