"Off" gait freezing and temporal discrimination threshold in patients with Parkinson disease.

OBJECTIVE

To investigate the relationship between temporal discrimination threshold (TDT) and "off" period gait freezing (OGF) in patients with fluctuating Parkinson disease (PD).

METHODS

TDT values were measured at the dorsum of the toes in 11 control subjects and 22 patients with PD with a wearing-off phenomenon (16 patients with OGF and 6 patients without OGF).

RESULTS

During the l-dopa "off" period, TDT values increased abnormally in both patient groups but were significantly higher in patients with OGF than in those without OGF. A positive correlation was found between the severity of OGF and TDT values measured by different point stimulation. In patients with OGF, a single dose of l-dopa treatment normalized TDT values and ameliorated OGF.

CONCLUSIONS

Dopa-responsive abnormal discriminative sensory processing may be a possible cause of "off" period gait freezing observed in patients with fluctuating Parkinson disease.