Effect of acute high-intensity resistance exercise on optic nerve sheath diameter and ophthalmic artery blood flow pulsatility

Exertional hypertension associated with acute high-intensity resistance exercise (RE) increases both intravascular and intracranial pressure (ICP), maintaining cerebrovascular transmural pressure. Carotid intravascular pressure pulsatility remains elevated after RE. Whether ICP also remains elevated after acute RE in an attempt to maintain the vessel wall transmural pressure is unknown. Optic nerve sheath diameter (ONSD), a valid proxy of ICP, was measured in 20 participants (6 female; 24±4yr, 24.2±3.9 kg m - 2) at rest (baseline), following a time-control condition, and following RE (5 sets, 5 repetition maximum bench press, 5 sets 10 repetition maximum biceps curls) using ultrasound. Additionally, intracranial hemodynamic pulsatility index (PI) was assessed in the ophthalmic artery (OA) by using Doppler. Aortic pulse wave velocity (PWV) was obtained from synthesized aortic pressure waveforms obtained via a brachial oscillometric cuff and carotid pulse pressure was measured by using applanation tonometry. Aortic PWV (5.2±0.5-6.0±0.7 m s -1, P<0.05) and carotid pulse pressure (45±17-59±19 mm Hg, P<0.05) were significantly elevated post RE compared with baseline. There were no significant changes in ONSD (5.09±0.7-5.09±0.7 mm, P>0.05) or OA flow PI (1.35±0.2-1.38±0.3, P>0.05) following acute RE. In conclusion, during recovery from acute high-intensity RE, there are increases in aortic stiffness and extracranial pressure pulsatility in the absence of changes in ICP and flow pulsatility. These findings may have implications for alterations in cerebral transmural pressure and cerebral aneurysmal wall stress following RE.