A novel computer-based technique for the assessment of tremor in Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disease and the diagnosis of its idiopathic form remains challenging. The diagnosis of idiopathic form is based on clinical features which can have poor sensitivity with about 25% of patients diagnosed as having the disease actually having other conditions. In this study we assess the suitability and clinical value of a low cost computer-based system as an aid to diagnosis of PD, in particular the presence of tremor. All participants (12 patients and 10 controls) performed a shape-tracing task using a graphic tablet attached to a laptop. To assess the presence of tremors in the collected data, a statistical spectral analysis of the moment-to-moment fluctuations in the position signal of the output from the digitising tablet was performed. This allowed the comparison of power spectrums obtained from the control and patient responses respectively. A peak in log power between the 5 Hz & 6 Hz can clearly be identified in the patient's spectrum and is indicative of Parkinson's related tremor and no similar peak could be seen in the control's spectrum, suggesting this type of sequential task and automated data analysis may be useful in the diagnosis of tremor.