Late Component of the Trigemino-Cervical Reflex: Clinical and Neuroradiological Correlations

The authors aimed to analyze the possible relationship of the late response of trigemino-cervical reflex (TCR) with various clinical conditions having brainstem lesions and lesion localizations in the brainstem.

The authors enrolled 30 healthy subjects, 16 patients with stroke, 14 patients with multiple sclerosis (MS), and 9 patients with neuro-Behçet disease. All patients had at least one MRI, and lesion localization was classified into midbrain, pons, medulla oblongata, or their combinations. The TCR was recorded simultaneously from bilateral sternocleidomastoid and splenius capitis muscles.

There was no significant difference based on lesion localization within the brainstem. Trigemino-cervical reflex latency was significantly longer in patients with MS compared with all other groups (P < 0.005 for each comparison). The Receiver Operating Characteristic curve analysis of sternocleidomastoid showed a cut-off value of 76.9 ms with 44% sensitivity and 92.7% specificity to predict MS. Similarly, the authors determined a cut-off value of 61.5 ms of splenius capitis latency with 38.5% sensitivity and 91.5% specificity to predict MS.

This study showed that TCR might be abnormal in a given patient with one brainstem lesion, independently from the lesion localization. This may be attributed to a broad network of TCR at the brainstem. Thus, abnormally delayed TCR responses can be used as a tool for the discrimination of MS among other brainstem lesions.