Table 1b.

Design and Aims of Treatment Studies

Study	Design/aims	Setting/participants	Diagnosis/comorbidities	VR technology/task	Outcome measures	Comparison task
Bourellier et al. [39]	Validation study (Repeated measures): To assess the use of a VR training environment to Engage Motor and Postural Abilities.	Department of Geriatrics, University of Bourgogne, France. N = 7 patients, average MMSE 23.2, Average timed up and go test 13.3 s N = 14, controls matched for age/gender, average MMSE 28.5, Average timed up and go test 9.5 secs	MCI, NINCDS-ADRDA criteria; comorbidities not mentioned, all normal/corrected normal hearing and vision	CAVE System with dimensions 3.40 m3, 3D vision via NVidia 3D Vision Pro stereoscopic glasses and ART DTrack 2motion tracking. Simulated fruit harvesting task designed to induce stretching: fruit in from different start positions are selected for ripeness and placed in a basket. 6* 3-min sessions with 1-min break between each session.	Number of appropriate movements: Ripe fruit picked on implicit VR task versus targeted movement on explicit exercise task.	Explicit exercise task: Arm pointing task with physiotherapist.
White and Moussavi. [40]	Case study: To determine whether an individual with AD could learn to navigate in a simple VR navigation environment	Department of Biomedical Engineering, University of Manitoba, Canada. N = 1, 74-year-old male, masters level education, MoCA 24/30	MCI, probable AD (no criteria given), comorbidities not mentioned.	Oculus Rift DK2 HMD: Participant is shown a room on the outside of a building and asked to navigate to it. 45-min training sessions, 3*week for 7 consecutive weeks (total 16 h)	Navigation errors, serial MoCA score.	Not used.
Optale et al. [41]	Case study: To explore whether cognitive processes could be restored via procedures practiced repetitively within an environment which contains functional real-world demands	Department of Neuro-Rehabilitation, Villa Salus Hospital, Venice, Italy. N = 1 Patient from memory clinic, female, aged 65, high school education.	Early onset AD (no criteria given). Full details of all comorbidities mentioned. No family history of dementia.	Virtual Research System HMD with Intersense motion tracker and Joystick control. Three listening experiences alternated with three different virtual experiences using Superscape VRT software: re-experience of childhood, participating in a tournament, and walking the streets of a modern city. Tasks gradually more complex. 15 min, 3* week for 12 weeks, then reduced to 3*weekly sessions every two weeks for a further 12 weeks (13. 5 h total).	Subjective measures of improvement, Multiple Delayed Reaction Verbochronometry and Neuropsychology measures (MMSE, Wechsler Memory Scale, Digit span, Praxia Tests, Frontal Lobe measures (towers of Hanoi, Stroop test), Visual-spatial Tests Cubes, Global Deterioration Scale) at baseline, 5, 8, and 12 months	Not used.
Micarelli et al. [42]	Case Control: Explore the effect of a head motion-dependent VR racing game on vestibular rehabilitation in UVH patients encompassing MCI and cognitively unimpaired older adults.	ITER Center for Balance and Rehabilitation Research, Rome, Italy. N = 24 patients with MCI (mean age 74.4, 14 females, mean MMSE 25.5) N = 23 controls (mean age 75.6, 12 females, mean MMSE 28.1)	MCI diagnosis according to Albert criteria (2011). Chronic UVH diagnosed by a 25% reduction in vestibular response to bithermal water caloric irrigation on one side 3 months after the beginning of symptoms. Exclusion: Significant medical disorders.	VR Tech: 5.2” display of a Windows Phone placed in the HMD ‘Revelation’ VR Headset. Trackspeed 3D racing game 20 min per day: point of view never ending racing race in which the car is steered from the cockpit by tilting the head	Otoneurological testing: Head impulse testing, Postuography. Self-report: Dizziness Handicap Inventory, activities-specific balance confidence scale, dynamic gait index. Simulator sickness Questionnaire, nausea oculomotor stress, and disorientation.	Vestibular rehabilitation only, twice daily 30–40 min in total.

UVH, unilateral vestibular hypofunction. See Table 1A for remaining abbreviations.