Amplification of fall risk in Parkinson's disease: the influence of comorbidities

Long term studies examining the progression of Parkinson's disease (PD) report the mean age of diagnosis to be in the mid sixties.' The diagnosis of PD typically .occurs after the presentation of motor deficits such as resting tremor, rigidity, hypokinesia, or postural instability. 2 Parkinson's disease in isolation results in worsening of motor deficits and progressive functional decline. While these problems are primarily the result of the degenerative process, underlying comorbidities may amplify or contribute to these deficits. In addition, given the typical age of onset, persons with PD will often present with a host of concurrent medical conditions (comorbidities). This is confirmed by research that estimated over 50% of Medicare beneficiaries had multiple comorbidities at the turn of the century.3