Case 08 of 8 · Clinician · BVP rehabilitation

Tracking rehabilitation in established bilateral vestibulopathy

A 45-year-old at 12 weeks of vestibular rehabilitation: DVA improved, vHIT gain unchanged.

CASE VIGNETTE

A 45-year-old man was diagnosed with idiopathic bilateral vestibulopathy 18 months ago after presenting with progressive oscillopsia and unsteadiness in darkness. Initial testing showed vHIT gain 0.4 bilaterally, caloric sum 4 °/s right, 5 °/s left — meeting Bárány 2017 BVP criteria. DVA loss at baseline was 0.5 logMAR symmetric in both directions.

He has been engaged in a structured vestibular rehabilitation programme for 12 weeks, attending physiotherapy twice weekly and performing prescribed gaze-stabilisation exercises daily. He reports subjective improvement in oscillopsia and is now able to read street signs while walking, which he could not do at presentation.

Repeat testing at 12 weeks: DVA loss has reduced to 0.25 logMAR symmetric. vHIT gain remains 0.4 bilaterally — unchanged from baseline. Caloric testing also unchanged. Tandem stance has improved from impossible at baseline to 8 seconds.

DVA SIGNATUREModerate

Bilateral vestibulopathy — established, on rehabilitation

DVA loss: Improved from 0.5 → 0.25 logMAR symmetric (50% functional improvement)
Laterality: Bilateral symmetric
Asymmetry: None
Corroborating tests: vHIT 0.4 bilaterally (unchanged) · caloric sum 4-5°/s (unchanged) · subjective oscillopsia improved · tandem stance improved

Key signature: The classic post-rehabilitation pattern in established BVP: DVA improves substantially without any change in measured peripheral VOR gain. The mechanism is well-timed covert catch-up saccades developing through gaze-stabilisation training, not hair-cell regeneration or recovered VOR.

Test-battery findings

DVA loss at baseline	0.5 logMAR symmetric
DVA loss at 12 weeks	0.25 logMAR symmetric (50% improvement)
vHIT gain at baseline	0.4 bilaterally
vHIT gain at 12 weeks	0.4 bilaterally (unchanged)
Caloric sum	Unchanged 4-5°/s per side
Tandem stance	Improved from impossible to 8 seconds
Subjective oscillopsia	Improved

Question

What is the most likely explanation for the improvement in DVA without any change in vHIT gain?

References

Cited references for this case (linked to the references page):

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Bilateral vestibulopathy — established, on rehabilitation

Test-battery findings

Question

Further reading

References