Table 2 Inclusion and exclusion criteria

Inclusion criteria (all)

≥18 years old; and

The individual has given written consent to participate in the study; and

New acute onset dizziness or vertigo since ≥24 h with pathological spontaneous or gaze-evoked nystagmus (i.e., acute vestibular syndrome, AVS). The nystagmus as described above must be present at screening (between 24 h and 7 days from onset) spontaneously, gaze-evoked or head-shake-evoked, and documented; and

Screening and inclusion within 7 days of onset of continuous symptoms; and

Symptomatic at inclusion

Exclusion criteria (any)

Pre-existing vestibular disease or neurological disease anticipated to affect the ability to participate in the study or the effect of the intervention. N.B: Recurring AVS with no set diagnosis before inclusion is accepted, as is past transient neurological diseases such as TIA or migraine; or

Inability to use the online rehabilitation tool, e.g., due to not having access to a computer, tablet, or smartphone, not having access to the internet or lacking in experience with such tools; or

Mental inability, reluctance or language difficulties that result in difficulty understanding the meaning of study participation; or

Medical and/or physical contraindications to making the required head movements (e.g., vertebral dissection) or otherwise participating in the training and testing exercises or data collection; or

Medication or other substance intake which can affect the ability to participate in the study or the reliability of the measurement methods. These medications include regular use of anticonvulsants, antiemetics/motion sickness medications, benzodiazepines, and neuroleptics. Transient corticosteroid and/or antiemetic treatment related to the current vertigo is accepted.