Hi Harriet!
Thanks for these questions! I’ll do my best to help!
1. The key here is that the patient is describing his dizziness as only imbalance. Someone with a unilateral vestibular hypofunction would likely experience imbalance AND dizziness (vertigo, lightheadedness, etc.) with head turns due to the asymmetry in left/right vestibular function. Similarly, we would expect a sensation of dizziness with BPPV (though this would likely be positional and not necessarily affect balance with all mobility) and central vestibular dysfunction. People with bilateral hypofunction often experience imbalance without dizziness. Another hint here is that the patient had a severe bacterial infection recently – and ototoxicity is a common cause of bilateral vestibular hypofunction.
2. This question is getting at the relatively slow progress expected with bilateral hypofunction (compared to unilateral hypofunction). The 2022 CPG recommends dosing balance exercises at 6-9 weeks minimum for bilateral hypofunction. It isn’t likely the patient will improve his FGA to 28/30 within one month. The MDC of 6 points is a great metric for goals and a reasonable goal for this patient would be meeting or exceeding the MDC to score >=27/30 within 2-3 months.
Hope this helps! 🙂
Chrissy