Clinical Case · clinician

Diplopia, imbalance and subtle reflex findings

History

A 36-year-old presents with intermittent diplopia and imbalance. Pure-tone hearing is normal bilaterally. Tympanometry is type A. Ipsilateral reflexes are normal; contralateral reflexes are absent bilaterally.

Findings

Pure-tone audiogram

0204060801002505001k2k4k8kFrequency (Hz)Hearing level (dB HL)
○ Right ear✕ Left ear

Acoustic reflex grid

Stim. Right
Stim. Left
Probe Right
Present
Absent
Probe Left
Absent
Present

Reflex decay (affected side)

0s2s4s6s8s10s0%50%100%50% criterion
Negative (normal) decay — amplitude is well maintained across the 10-second hold.

Which interpretation best fits the crossed-uncrossed dissociation?