Validation of the National Institute of Neurological Disorders and Stroke Criteria for Psychosis in Parkinson Disease.

OBJECTIVES: Parkinson disease (PD) psychosis is a condition associated with several negative outcomes. Despite its impact, there is a lack of validated diagnostic tools for this condition. In this study, we aim to verify the validity of the proposed NINDS criteria for PD psychosis and explore its possible applications in clinical practice. DESIGN, SETTINGS, PARTICIPANTS: We prospectively selected 104 subjects with idiopathic PD referred to a movement disorder clinic for a cross-sectional evaluation. MEASUREMENTS: A neurological evaluation confirmed idiopathic PD and classified PD psychosis according to the NINDS criteria. A psychiatrist then classified the subject according to DSM-IV-TR criteria for psychosis, considered the reference standard. We used Cohen's kappa (κ) to quantify reliability between methods. Finally, we designed models assigning a weighted score to each characteristic psychotic symptom from the NINDS criteria (criterion A), and plotted receiver operating curves for each model. RESULTS: Of the total sample, 52 (50%) met proposed criteria for NINDS PD psychosis and 16 (15.6%) met reference standard criteria. Inter-rater reliability showed only a fair agreement (κ = 0.30). By using a scoring approach for each NINDS criteria item and a cutoff total score for the diagnosis of PD psychosis, we significantly increased the agreement for diagnosis reliability (κ = 0.72), with sensitivity of 94% and specificity of 91%. CONCLUSIONS: Although the NINDS criteria had limited reliability for diagnosing PD psychosis, a scoring approach for symptoms showed good reliability, with sensitivity and specificity above 90%. This scoring approach may be an accurate tool for identifying patients with PD psychosis.

Clinical Implications of the National Institute of Neurological Disorders and Stroke Criteria for Diagnosing Psychosis in Parkinson's Disease.

The effect of psychotic symptoms in Parkinson's disease (PD) is variable among patients, and different methods to assess psychosis may yield conflicting results. A sample of 102 patients with a diagnosis of idiopathic PD underwent neurological, psychiatric, and neuropsychological assessment. Participants were divided into three groups: those who met DSM criteria for psychotic disorder, those who had psychotic symptoms but did not meet DSM criteria, and those without any psychotic symptoms. The first group had significantly worse sleep and worse cognitive and psychopathological symptoms compared with the other two groups. Results suggested that patients meeting DSM criteria for psychotic disorder comprise a separate clinical category.

Fields of Forel Brain Stimulation Improves Levodopa-Unresponsive Gait and Balance Disorders in Parkinson's Disease.

BACKGROUND: Gait and balance disturbance are challenging symptoms in advanced Parkinson's disease (PD). Anatomic and clinical data suggest that the fields of Forel may be a potential surgical target to treat these symptoms. OBJECTIVE: To test whether bilateral stimulation centered at the fields of Forel improves levodopa unresponsive freezing of gait (FOG), balance problems, postural instability, and falls in PD. METHODS: A total of 13 patients with levodopa-unresponsive gait disturbance (Hoehn and Yahr stage ≥3) were included. Patients were evaluated before (on-medication condition) and 1 yr after surgery (on-medication-on-stimulation condition). Motor symptoms and quality of life were assessed with the Unified Parkinson's Disease Rating scale (UPDRS III) and Quality of Life scale (PDQ-39). Clinical and instrumented analyses assessed gait, balance, postural instability, and falls. RESULTS: Surgery improved balance by 43% (95% confidence interval [CI]: 21.2-36.4 to 35.2-47.1; P = .0012), reduced FOG by 35% (95% CI: 15.1-20.3 to 8.1-15.3; P = .0021), and the monthly number of falls by 82.2% (95% CI: 2.2-6.9 to -0.2-1.7; P = .0039). Anticipatory postural adjustments, velocity to turn, and postural sway measurements also improved 1 yr after deep brain stimulation (DBS). UPDRS III motor scores were reduced by 27.2% postoperatively (95% CI: 42.6-54.3 to 30.2-40.5; P < .0001). Quality of life improved 27.5% (95% CI: 34.6-48.8 to 22.4-37.9; P = .0100). CONCLUSION: Our results suggest that DBS of the fields of Forel improved motor symptoms in PD, as well as the FOG, falls, balance, postural instability, and quality of life.