Little is known about vestibular-related timing processes in patients with disequilibrium. Patients with a history of migraine headaches often complain of significant motion sensitivity and long-term vague imbalance inconsistent with a peripheral vestibular disorder. Some of these people have episodic spells of severe vertigo termed “vestibular migraines.” Other patients have no history of migraine but do report significant motion sensitivity. Motion sensitivity has typically been explained as a mismatch between the amplitude of vestibular and other (typically visual) sensory inputs.

Another possibility is that motion sensitive patients may suffer from a mismatch in the temporal integration of vestibular and other sensory inputs. Here, we compared the temporal binding window (TBW) of vestibular + auditory stimuli in normal subjects, subjects with motion sensitivity, and those with both migraine and motion sensitivity. We asked subjects undergoing earth-vertical sinusoidal rotations at 0.5 Hz, 12 deg/sec to identify whether a metronome-like series of tone bursts was synchronous with their cyclic motion. We calculated the TBW as the range in time encompassing the middle 68% of the area under the psychometric curve.

The TBW in normal subjects was 312 +/- 135 ms (mean +/- SD), in subjects with motion sensitivity was 454 +/- 103 ms, and in subjects with migraine and motion sensitivity was 451 +/- 124 ms. The TBW of normal subjects was significantly shorter than the other groups. Temporal errors in perception, as manifested by a prolongation of the TBW, are a plausible mechanism for imbalance in patients with migraine and motion sensitivity.