Interictal hemodynamic abnormality during motor activation in sporadic hemiplegic migraine: An explorative study
1National Neuroscience Institute, Singapore; Singapore General Hospital, Singapore; Duke-NUS Medical School, Singapore.
Introduction:
The motor weakness in sporadic hemiplegic migraine (SHM) is a poorly understood aura manifestation. Cortical spreading depression affecting motor excitability and alterations of neurovascular coupling may be integral to the development of migraine aura.
Methods:
We studied 10 right-handed SHM patients and 17 healthy controls with functional near-infrared spectroscopy (fNIRS) in the interictal period. Subjects performed a finger opposition task and had real time determination of oxyhemoglobin (OxyHb) and deoxyhemoglobin (deOxyHb) changes. Recordings were completed with 10 left and 10 right sided cortical channels.
Results:
Mean baseline to peak changes were significantly reduced in SHM patients as compared to controls bilaterally only for OxyHb measurements in the anteromedial channels. Mean time to peak changes were significant delayed in SHM patients compared to controls bilaterally largely for OxyHb measurements in the posterolateral channels, with the exception of 2 recording channels.
Conclusions:
Our findings suggest presence of abnormal interictal hemodynamic responses to increased metabolic demands during motor activation in SHM. These bilateral cerebrovascular changes involve OxyHb to a much larger degree than deOxyHb. Baseline to peak changes were evident more in the anteromedial channels, whereas time to peak changes were more evident in the posterolateral channels. These findings suggest that oxygen inflow into specific brain regions may be defective in SHM as opposed to oxygen utilization. Our findings suggest that in SHM, enduring hemodynamic deficits in response to an impending motor task are evident, which can be further explored in future studies, and possibly therapeutic trials.
