Improving Functional Disability and Cognition in Parkinson Disease: Randomized Controlled Trial

Assessment protocol:

• Cognitive Evaluation: The cognitive battery included assessments to evaluate processing speed, verbal learning and memory, visual learning and memory and executive functioning. All cognitive measures were converted into Z-scores based on the pooled PD group, and the sign of some measures was adjusted so that higher scores indicated better cognitive performance. All composite cognitive domains maintained satisfactory internal consistency. Processing Speed (Cronbach's α = 0.85) was quantified based on the Trail Making Test-A and Salthouse Letter Comparison Test. For verbal learning and memory (α = 0.88), learning and long-term recall performance on the Hopkins Verbal Learning Test (version 2 at baseline and 4 at post-treatment) were utilized. For visual learning and memory (α = 0.96), learning and long-term recall performance on the Brief Visual Memory Test (version 1 at baseline and 3 at post-treatment) were used (α = 0.96). Executive functioning (α = 0.78) was determined based on the Stroop test, using the word-color and interference scores.

Theory of mind (TOM). The strange stories test (Happé test) was administered to evaluate TOM. Four different stories (concerning double bluff, mistakes, persuasion and white lies) were administered at baseline and follow-up, and they were summed into a total TOM score with a possible range of 0 to 8. Higher scores indicate better TOM.

• Premorbid intelligence quotient and cognitive reserve. The Accentuation Reading Test (TAP), the Spanish version of the National Adult Reading Test (NART), was administered to calculate an estimation of each patient´s premorbid intelligence. The scale ranged from 0 to 30. Cognitive reserve was estimated using the Cognitive Reserve questionnaire. This 15-item multiple-choice questionnaire includes questions about education/culture, working activity, leisure and hobbies, physical activities and social activities. Higher scores indicate a better cognitive reserve, and the scale ranged from 0 to 26.
• Global cognitive status. The Mini-Mental State Examination (MMSE) was administered to obtain a general mental status score.
• Medication use. Medications, dosages and dose frequencies were used to calculate the levodopa-equivalent daily dose (mg/day) (LEDD).
• PD assessment. The Unified Parkinson's Disease Rating Scale and the Hoehn & Yahr scale were used for the assessment of the course and stage of the disease.
• Depressive symptoms. Geriatric Depression Scale (GDS-15) includes 15 items. Higher scores represent a higher degree of depression (range from 0 to 15).
• Neuropsychiatric symptoms. The NPI-Q was administered to evaluate neuropsychiatric symptoms. The test includes 10 items (delusions, hallucinations, agitation/aggression, depression/dysphoria, anxiety, euphoria, apathy, disinhibition, irritability and aberrant motor behavior). These sub-scales were summed into a total score with a possible range of 0 to 120. Higher scores indicate more frequent and severe neuropsychiatric symptoms.
• Apathy. The Lille apathy rating scale consists of 33 items, including 9 sub-scales (everyday productivity, interests, taking initiative, novelty seeking/motivation, emotional responses, concern, social life and self-awareness). These sub-scales were summed into a total apathy score with a possible range of -36 to 36. Lower scores indicate less apathy.
• Functional disability. Functional disability was self administered using the World Health Organization Disability Assessment Schedule II (WHO-DAS II), short version (12 items).

Description of the intervention: