HAND GRIPPING EFFECT ON CEREBRAL BLOOD FLOW iN NORMAL SUBJECT

HAND GRIPPING EFFECT ON CEREBRAL BLOOD FLOW iN NORMAL SUBJECT

Purpose: The changes of regional cerebral blood flow (rCBV) related to metabolic demand depends on both integrity of neuronal function and vascular blood flow. Therefore, we assessed the motor stimulus to blood flow velocity (BFV) changes of bilateral middle cerebral arteries (MCA) by transcranial Doppler (TCD) sonography in normal subjects. Methods: Sixteen subjects (8 female, aged 48.0±3.8 years; 8 male, aged 54.4±4.8 years) were investigated. Bilateral TCD sonography from both MCA were monitored during 10 cycles of 20 seconds when subjects are performing hand gripping with a frequency of one per second, and subsequently 20 seconds when they are rest to assess BFV changes on activated cortical motor areas. BFV increase was calculated off-line for each subjects. Results: Hand gripping showed a significant BFV increase on both MCA (p=0.000). These values were 19.2% on the left side, and 19.2% on the right side. There was no significant side to side difference between the absolute BFV values both at rest and during hand gripping. The left side, however, showed slightly higher absolute BFVs than that of right side. Additionally, the absolute BFVs and BFV increases were not significantly different between male and female subjects. However, male subjects hada lower BFVs at rest and during hand gripping comparing to female subjects. Conclusion: We, however, have a small sample size, and this test requires the subject cooperation. Our results suggest that hand gripping can successfully affect blood flow in both MCA without side to side differences. Finally, our suggestion is this test might be useful to assess the neurovascular integrity.