The prevalence of fatigue following deep brain stimulation surgery in Parkinson's disease and association with quality of life.

Fatigue is a common and disabling nonmotor symptom seen in Parkinson's disease (PD). While deep brain stimulation surgery (DBS) improves motor symptoms, it has also been associated with non-motor side effects. To date no study has utilized standardized instruments to evaluate fatigue following DBS surgery.

Greater motor improvement in right hemibody Parkinson's patients after dopaminergic medications.

Due to motor and neuropathological asymmetries, Parkinson's disease (PD) patients with right hemibody onset (RHO) of symptoms may experience greater benefit from dopaminergic enhancing medications, relative to patients with left hemibody onset (LHO). We investigated this possibility by measuring UPDRS scores of 20 PD patients with LHO and 13 patients with RHO, both prior and subsequent to taking dopaminergic enhancing medications. Following treatment, the motor score from the UPDRS improved for both groups of patients.

Spreading activation of lexical-semantic networks in Parkinson's disease.

Although dopamine may act as a neuromodulator of spreading activation within semantic networks, this role of dopamine in lexical networks has not been investigated. Hence, we sought to investigate the effects of Parkinson's disease (PD), which is associated with dopamine depletion, on spreading activation in the lexical networks. Ten Parkinson's disease patients and 11 normal controls performed the controlled oral word association test and the average word frequency for their responses was calculated and used as an index of spreading activation.