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Pedunculopontine nucleus region deep brain stimulation (DBS) is a promising but experimental therapy for axial motor deficits in Parkinson's disease (PD), particularly gait freezing and falls. Here, we summarise the clinical application and outcomes reported during the past 10 years. The published dataset is limited, comprising fewer than 100 cases. Furthermore, there is great variability in clinical methodology between and within surgical centers. The most common indication has been severe medication refractory gait freezing (often associated with postural instability). Some patients received lone pedunculopontine nucleus DBS (unilateral or bilateral) and some received costimulation of the subthalamic nucleus or internal pallidum. Both rostral and caudal pedunculopontine nucleus subregions have been targeted. However, the spread of stimulation and variance in targeting means that neighboring brain stem regions may be implicated in any response. Low stimulation frequencies are typically employed (20-80 Hertz). The fluctuating nature of gait freezing can confound programming and outcome assessments. Although firm conclusions cannot be drawn on therapeutic efficacy, the literature suggests that medication refractory gait freezing and falls can improve. The impact on postural instability is unclear. Most groups report a lack of benefit on gait or limb akinesia or dopaminergic medication requirements. The key question is whether pedunculopontine nucleus DBS can improve quality of life in PD. So far, the evidence supporting such an effect is minimal. Development of pedunculopontine nucleus DBS to become a reliable, established therapy would likely require a collaborative effort between experienced centres to clarify biomarkers predictive of response and the optimal clinical methodology. © 2017 International Parkinson and Movement Disorder Society.

The objective of our study was to compare Movement Disorder Society Task Force criteria for diagnosis of Parkinson's disease dementia (PDD) with the gold standard of traditional neuropsychological testing. A short checklist (Level I) and a protocol of neuropsychological tests (Level II) have been proposed by a Movement Disorder Society Task Force but not fully validated in clinical practice. Ninety-one Parkinson's disease (PD) subjects were categorized as having dementia or no dementia based on a battery of neuropsychological test results and clinical judgment. The isolated components needed for Level I and Level II diagnoses were then culled from the neuropsychological evaluations and independently used to designate PDD. Compared with traditional neuropsychological testing, the sensitivity and specificity of Level I criteria for PDD was 66.7% and 98.8%, and for Level II criteria 100% and 92.7%, respectively. Using Level II criteria, 6 additional subjects were diagnosed with PDD that were classified as having no dementia when full neuropsychological data were used for the diagnosis. These 6 subjects had more education years and were less impaired on cognitive tests. The Movement Disorder Society's Level II criteria more frequently classify subjects with PDD than does traditional neuropsychological testing. Whereas Level II criteria may overclassify subjects as having PDD, they are very accurate in ruling out dementia. Movement Disorder Society's criteria are practical and timesaving, although full neuropsychological testing may still be needed. © 2014 International Parkinson and Movement Disorder Society

The objective of this work was to evaluate the Movement Disorders Society (MDS) Task Force-proposed screening checklist for detecting Parkinson's disease dementia (PD-D) in relation to full neuropsychological testing. An MDS Task Force has proposed diagnostic procedures for PD-D, which have not been fully validated against more extensive neuropsychological testing. PD subjects were recruited from 2 specialty centers. A neuropsychologist evaluated them for dementia as part of routine clinical care. Independent clinical neurologists administered the MDS PD-D screening checklist. Diagnosis of PD-D by the 2 methods was compared. Ninety-one PD subjects had a mean age of 66.3 (SD = 9.7) years and a mean PD duration of 8.8 (SD = 6.1) years. Seven subjects (7.7%) met all 8 screening checklist criteria from the MDS PD-D screening tool and were classified as probable PD-D. Fifteen (16.5%) subjects were classified as PD-D by full neuropsychological assessment. The screening checklist showed 100% specificity, but only 46.7% sensitivity, for diagnosing PD-D compared to the full neuropsychological assessment. PD-D cases missed by the PD-D screening tool were largely due to 2 checklist items that were not endorsed (absence of depression and Mini-Mental State Examination [MMSE] scores

We review the impact of dystonia and its surgical treatment with deep brain stimulation (DBS) on cognitive function, psychiatric morbidity, and health-related quality of life. The current evidence suggests that globus pallidus internus (GPi) DBS does not cause cognitive decline in primary dystonia. However, we recommend general preoperative screening of cognition in patients with dystonia to evaluate baseline cognitive status and monitor for possible postoperative changes. Patients with mild to moderate depression appear to do well postoperatively; however, there are scant data about those with severe depression. This is particularly problematic given reports of postoperative suicide. Patients with tardive dystonia seem to do well post-GPi DBS despite often having a history of depression or even having active severe depression. We make recommendations for screening and basic management strategies of patients identified as having a major psychiatric illness pre- or postoperatively. Quality of life in dystonia patients quantified by generic measures such as the SF36 showed improvement in both mental and physical categories following DBS surgery. (C) 2011 Movement Disorder Society

To evaluate the effects of the dopamine D2-D3 agonist ropinirole in patients who developed apathy after complete withdrawal from dopaminergic medication following successful subthalamic nucleus (STN) stimulation for advanced Parkinson disease (PD). We assessed apathy (Apathy Scale, Apathy Inventory), mood (Montgomery-Asberg Depression Rating Scale), cognitive functions (Mattis Dementia rating scale, frontal score, executive tests) and motor state (UPDRS-III) in 8 PD patients treated with STN stimulation without dopaminergic treatment and who became apathetic. Assessments were made at baseline and after 6 weeks of ropinirole treatment (7.2 +/- 5.9 mg/d; range 1-18 mg/d). Apathy improved with ropinirole in all but 1 patient (54 +/- 24%; range 0-78%). Mood also improved (75 +/- 31%; range 0-100%), but not in correlation with the change in apathy. Cognitive performance was not modified. Stimulation contacts were located within the STN in all patients except the one who remained apathetic in spite of ropinirole treatment (zona incerta). We suggest that apathy, which was compensated for by an enhancement of D2-D3 receptor stimulation in PD patients with STN stimulation: (1) depends on a dopaminergic deficit in associativo-limbic areas of the brain and (2) can be avoided if a dopaminergic agonist is administered postoperatively.