Globus Pallidus Stimulation to Treat Insomnia

Inclusion Criteria: * 40-80 years of age * Symptomatic with Parkinsonism for 7-20 years * Severe insomnia based on ISI score Exclusion Criteria: * Clinically significant dementia (MMSE \<23) * Hoehn \& Yahr \[Hoehn, 1967 #1839\] stage I or V disease * Other significant neurological or psychiatric disease * Previous pallidotomy or thalamotomy * Previous placement of other implantable devices * Secondary parkinsonism (non-idiopathic parkinsonism) * Inability to travel to Jacksonville for post-operative study visits * Severe sleep apnea * Insomnia due to pain or untreated mood disorder * Contraindications to 3T MRI * Circadian rhythm sleep disorders. * Current use of hypnotics