Table 1

Basic characteristics, diagnosis and symptoms of the four cases

Case 1Case 2Case 3Case 4
CF mutationCarrying one CF mutation dF508dF508/R117HdF508/Y1092XdF508/dF508
Age (years)35573544
Weight (kg)117505058
eGFR (mL/min)>60>60>60>60
Mean tobramycin dose (mg/kg/24 hours)4.911.810.48.8
Treatment duration (days)27211521
Clinical/outpatient administrationOutpatientClinicalOutpatientBoth
Time to vestibulotoxicity (days after first treatment day)21251330
Unilateral/bilateral vestibulotoxicityBilateralBilateralUnilateralUnilateral
Reversible/irreversible vestibulotoxicityIrreversibleIrreversibleReversibleReversible
Diagnosis of vestibular hypofunction (electro-nystagmography (ENG))Bilateral vestibulopathyNo central vestibular hypofunction, bilateral non-irritable labyrinthsNo central vestibular hypofunction, non-irritable right labyrinthNo central vestibular hypofunction, less irritable right labyrinth
Description of symptomsDizziness, imbalance, reduced memory and concentration, increased imbalance with head movementsDizziness, nausea, vomiting, increased dizziness with head movements, unable to walk, pressing headache, slurred speechDizziness, imbalance, increased dizziness with head movements, nausea and vomiting in the morningDizziness, cannot climb stairs, drive, cycle, walk alone
Follow-up of symptomsRehabilitation process, questioning symptoms, symptoms partly disappear and are stable, dependent on mobility scooterRehabilitation process, questioning symptoms, symptoms remain, dependent on mobility scooterQuestioning symptoms, symptoms partly disappearQuestioning symptoms, physiotherapy, disappear over time
Diagnosis hearing loss (audiogram)Conductive hearing loss indicated by PCDBilateral high frequency perceptual lossUnilateral left high frequency perceptual lossNormal hearing
  • CF, cystic fibrosis; PCD, primary ciliary dyskinesia.