Brain Activity During Complex Walking in People With Atypical Parkinsonian Syndromes

• Assessment of brain activity with fNIRS and behavioural assessments (motor, motor-cognitive and cognitive) during three complex walking conditions. (Other): Dual-task walking with the auditory stroop task. Navigational walking - a course consisting of a distribution of 45 and 90 degrees turns to the left and right Navigational and dual-task walking (condition 1 and 2 together)

Primary outcomes

• Functional near infrared spectrometry (fNIRS) [Baseline]: The measurement of changes in concentration of HbO and HHb in the prefrontal cortex will be assessed using a NIRSPORT 2 (NIRx Medizintechnik, Berlin, Germany) device.
• Gait performance during all conditions [Baseline]: Gait variables such as stride time and/or velocity will be analyzed with the APDM mobility system.
• Dual-task performance-reaction time [Baseline]: Cognitive performance of the dual task will be assessed as errors in the response to the Auditory Stroop task.

Secondary outcomes

• Resting-state functional near infrared spectrometry (rsfNIRS) [Baseline]: The measurement of changes in concentration of HbO and HHb in the whole cortex will be assessed using a NIRSPORT 2 (NIRx Medizintechnik, Berlin, Germany) device during 2x 10min of rest, while seated in a comfortable chair.
• Cognitive function- composite score [Baseline]: The cognitive test battery comprised the following tests: The Color-Word Interference Test (CWIT), Verbal Fluency, Trail Making Test (TMT), Ray Auditory Verbal Learning Test (RAVLT), and Symbol Digit Modalities Test (SDMT). Cognitive function will be assessed as a composite measure of these tests together.
• Cognitive function - verbal fluency [Baseline]: Verbal function, initiation \& task-set switching with the Verbal Fluency test from D-KEFS (Delis-Kaplan Executive Function System).
• Cognitive function - Attention and psychomotor processing speed [Baseline]: Attention and psychomotor processing speed will be assessed with the Trail Making Test (TMT) from D-KEFS (Delis-Kaplan Executive Function System).
• Cognitive function - Episodic memory [Baseline]: Episodic memory will be assessed with the Ray Auditory Verbal Learning Test (RAVLT).
• Cognitive function - Inhibition & task-set switching [Baseline]: Inhibition \& task-set switching with the Color-Word Interference Test (CWIT) from D-KEFS (Delis-Kaplan Executive Function System)
• Self-reported level of physical activity [Baseline]: Assessed with the Frändin-Grimby Scale (score 1-6, higher score=better)
• Physical activity [Baseline]: Assessed with accelerometers (Actigraph GT3X+) for seven consecutive days after the clinical visit
• Motor function/disease severity [Baseline]: Assessed with the movement Disorders Society- Unified Parkinson's Disease Rating Scale (MDS-UPDRS). Higher scores = worse/more symptoms
• Balance performance [Baseline]: Assessed with the Mini-BESTest (Balance Evaluation Systems test), 0-28p,
• Anxiety and depression [Baseline]: Assessed with Hospital Anxiety and Depression Scale (HADS), 0-24 on the depression and anxiety part respectively. Lower score=better
• Walking ability [Baseline]: Self-assessed walking ability with the WALK-12G.
• Dual-task performance -errors [Baseline]: Cognitive performance of the dual task will be assessed as the reaction time to respond during the Auditory Stroop
• Disability [Baseline]: WHO Disability Assessment Schedule (WHODAS) version 2.0, 12 self-assessed questions (12 to 60) more points=worse

Sex: All

Inclusion Criteria:

* clinical diagnosis of PSP according to Movement Disorder Society (MDS) (2017) or
* MSA according to MDS criteria (2022)
* the ability to walk with or without a mobility device for ≤5 minutes continuously

Exclusion Criteria:

* cognitive difficulties affecting the ability to understand and/or follow verbal/written - instructions
* severe freezing of gait
* Severe hearing or visual impairments that affect participation in the assessments
* Other neurological diseases
* Other diseases that can affect gait or balance.

• Franziska Albrecht, PhD, Principal investigator, Karolinska Institutet
• Erika Franzén, Prof,, Principal investigator, Karolinska Institutet