Clinical rating scale for pantothenate kinase-associated neurodegeneration: A pilot study.

BACKGROUND: Pantothenate kinase-associated neurodegeneration is a progressive neurological disorder occurring in both childhood and adulthood. The objective of this study was to design and pilot-test a disease-specific clinical rating scale for the assessment of patients with pantothenate kinase-associated neurodegeneration. METHODS: In this international cross-sectional study, patients were examined at the referral centers following a standardized protocol. The motor examination was filmed, allowing 3 independent specialists in movement disorders to analyze 28 patients for interrater reliability assessment. The scale included 34 items (maximal score, 135) encompassing 6 subscales for cognition, behavior, disability, parkinsonism, dystonia, and other neurological signs. RESULTS: Forty-seven genetically confirmed patients (30 ± 17 years; range, 6-77 years) were examined with the scale (mean score, 62 ± 21; range, 20-106). Dystonia with prominent cranial involvement and atypical parkinsonian features were present in all patients. Other common signs were cognitive impairment, psychiatric features, and slow and hypometric saccades. Dystonia, parkinsonism, and other neurological features had a moderate to strong correlation with disability. The scale showed good internal consistency for the total scale (Cronbach's α = 0.87). On interrater analysis, weighted kappa values (0.30-0.93) showed substantial or excellent agreement in 85% of the items. The scale also discriminated a subgroup of homozygous c.1583C>T patients with lower scores, supporting construct validity for the scale. CONCLUSIONS: The proposed scale seems to be a reliable and valid instrument for the assessment of pediatric and adult patients with pantothenate kinase-associated neurodegeneration. Additional validation studies with a larger sample size will be required to confirm the present results and to complete the scale validation testing. © 2017 International Parkinson and Movement Disorder Society.

Pain in Parkinson disease: a review of the literature.

Parkinson's disease (PD) is a degenerative neurological disease presenting with motor and non-motor signs and symptoms. Approximately 30-50% of the patients experience pain. There is no consensus regarding the mechanisms and classification of pain in PD. This paper reviews current data on the possible mechanisms, classifications, evaluation and potential risk factors for pain in PD. Literature searches were performed to identify clinical trials and reviews covering patho-physiology, classification, type, evaluation and risk factors associated with pain in PD. Pain in PD could be related to pathologic changes in the anatomic structures involved in nociceptive mechanisms. Studies on pain mechanisms have been mostly conducted in animals. The mechanism of pain is complicated and influenced by different factors. There are several methodological differences between the studies trying to classify pain and to characterize its subtypes. Potential risk factors for pain in PD include: age, gender, and duration of the disease. Although pain is one of the non-motor symptoms most frequency experienced by patients, it is often under recognized and inadequately treated in contrast to motor symptoms Multicenter studies are needed that include a large cohort of subjects evaluated in multiple dimensions including pain in order to obtain more data and to allow improved management of pain in patients with PD.