Tania Gavilán Iglesias, Pablo Martínez-Martín, Lidia Vela, Fuencisla Gutiérrez, Luis González Gutiérrez, Leonidas Stefanis, Vincenzo Lupo, Paula Pires, Miguel Coelho, Julio Ramos Lizana, Miguel Tomás Vila, Belén Pérez Dueñas, Joaquim Ferreira, Carlos Hernández Lahoz, Laura Martí Sánchez, Nardo Nardocci, María Josep Martí, Ana Castro Caldas, Montserrat Pujol, Cristina Garrido, Giovanna Zorzi, Itziar Gastón, Paulo Rego, Fradique Moreira, Loreto Martorell, Jean Pierre Lin, Kylee Tustin, Gustavo Lorenzo Sanz, Marina Magalhães, Alejandra Darling, Carmen Espinós, Leonor Correia Guedes, María Stamelou, Cristina Costa, Cristina Tello, Marcos Madruga, Sergio Aguilera-Albesa, Carmen Rodríguez-Blazquez, Teresa Temudo, Daniel Cuadras Pallejà, Juan Darío Ortigoza Escobar, Pedro J. García, Roser Pons
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
