Is Counterpulsation a Potential Therapy for Ischemic Stroke?

Wong, Ka Sing

doi:10.1159/000139655

Cited by 23 publications

(15 citation statements)

References 93 publications

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“…Blood flow to the ischemic penumbra is known to be CPP dependent as normal cerebral blood flow autoregulation is lost in the ischemic penumbra, 24 so ICP elevation would be predicted to reduce penumbral perfusion. The principle of increasing CPP to enhance collateral flow and penumbral perfusion has been exploited in several clinical trials; [25][26][27][28][29][30][31] however, to date, these have all focused on mean arterial pressure (MAP) rather than intracranial pressure (CPP = MAP − ICP).…”

Section: Discussionmentioning

confidence: 99%

Intracranial Pressure Elevation after Ischemic Stroke in Rats: Cerebral Edema is Not the Only Cause, and Short-Duration Mild Hypothermia is a Highly Effective Preventive Therapy

Murtha

McLeod

Pepperall

et al. 2014

J Cereb Blood Flow Metab

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In both the human and animal literature, it has largely been assumed that edema is the primary cause of intracranial pressure (ICP) elevation after stroke and that more edema equates to higher ICP. We recently demonstrated a dramatic ICP elevation 24 hours after small ischemic strokes in rats, with minimal edema. This ICP elevation was completely prevented by short-duration moderate hypothermia soon after stroke. Here, our aims were to determine the importance of edema in ICP elevation after stroke and whether mild hypothermia could prevent the ICP rise. Experimental stroke was performed in rats. ICP was monitored and shortduration mild (35°C) or moderate (32.5°C) hypothermia, or normothermia (37°C) was induced after stroke onset. Edema was measured in three studies, using wet-dry weight calculations, T 2 -weighted magnetic resonance imaging, or histology. ICP increased 24 hours after stroke onset in all normothermic animals. Short-duration mild or moderate hypothermia prevented this rise. No correlation was seen between ΔICP and edema or infarct volumes. Calculated rates of edema growth were orders of magnitude less than normal cerebrospinal fluid production rates. These data challenge current concepts and suggest that factors other than cerebral edema are the primary cause of the ICP elevation 24 hours after stroke onset.

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Section: Discussionmentioning

confidence: 99%

Intracranial Pressure Elevation after Ischemic Stroke in Rats: Cerebral Edema is Not the Only Cause, and Short-Duration Mild Hypothermia is a Highly Effective Preventive Therapy

Murtha

McLeod

Pepperall

et al. 2014

J Cereb Blood Flow Metab

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“…ECP could be used as a new method in treatment of ischemic stroke. 3 ECP operates through external pressure applied on pneumatic cuffs on lower extremities with advantages of easy manipulation, adjustable pressure, and good tolerance. Usually, ECP treatment takes 35 hours (daily 1 hourly session) and lasts for 7 weeks.…”

Section: Discussionmentioning

confidence: 99%

“…1,2 ECP has been investigated for ischemic stroke, 3 and a recent review suggests ECP is associated with a remarkable increase in the number of ischemic stroke patients with neurological improvement. 4 In the ECP system, there are 3 pairs of pneumonic cuffs applied to the calves, lower thighs, and upper thighs.…”

mentioning

confidence: 99%

External Counterpulsation Augments Blood Pressure and Cerebral Flow Velocities in Ischemic Stroke Patients With Cerebral Intracranial Large Artery Occlusive Disease

Lin

Xiong

Han

et al. 2012

Stroke

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Background and Purpose— External counterpulsation (ECP) is a novel noninvasive method used to improve the perfusion of vital organs, which may benefit ischemic stroke patients. We hypothesized that ECP may augment cerebral blood flow of ischemic stroke patients via induced hypertension. Methods— We recruited ischemic stroke patients with cerebral intracranial large artery occlusive disease and healthy elderly controls into this study. Bilateral middle cerebral arteries of subjects were monitored using transcranial Doppler. Flow velocity changes before, during, and after ECP were, respectively, recorded for 3 minutes while continuous beat-to-beat blood pressure data were recorded. Cerebral augmentation index was the increase in percentage of middle cerebral artery mean flow velocity during ECP compared with baseline. Transcranial Doppler data were analyzed based on ipsilateral or contralateral to the infarct side. Results— ECP significantly increased mean blood pressure of stroke patients and controls. During ECP, middle cerebral artery mean flow velocities of stroke patients increased on both ipsilateral and contralateral sides when compared with baseline (ipsilateral cerebral augmentation index, 9.64%; contralateral cerebral augmentation index, 9%; both P <0.001), but there was no increase in difference between the 2 sides when compared with each other. Mean flow velocities of controls did not change under ECP. After ECP, blood pressure and flow velocity of stroke patients returned to baseline level. Conclusion— ECP provides a new method of cerebral blood flow augmentation in ischemic stroke by elevation of blood pressure. Flow augmentation induced by ECP suggests the improvement of cerebral perfusion and collateral supply from infarct ipsilateral and contralateral sides.

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“…This is supported by further studies. However, most of these studies show methodological shortcomings [14,15]. Last but not least, the effect of ECP on CBFV even in healthy subjects is controversial due to limited and conflicting data.…”

Section: Introductionmentioning

confidence: 99%

Does External Counterpulsation Augment Mean Cerebral Blood Flow in the Healthy Brain? Effects of External Counterpulsation on Middle Cerebral Artery Flow Velocity and Cerebrovascular Regulatory Response in Healthy Subjects

Junge-Huelsing

Liman²,

Brunecker³

et al. 2010

Cerebrovasc Dis

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Background and Purpose:External counterpulsation (ECP) noninvasively improves myocardial and organ perfusion via diastolic augmentation. The effects on cerebral blood flow velocities (CBFV) and hemodynamics are controversial. In this study, the effect of active ECP treatment on CBF in healthy subjects was continuously measured. Methods: In 9 healthy volunteers (mean age 34.1 ± 11.1 years, 4 females), 20-min active ECP treatment was performed. CBFV in the middle cerebral artery were detected via transcranial Doppler. CBFV were registered continuously before, during and after ECP. The protocol was repeated twice. Results: At onset of ECP, immediate changes in CBFV were observed: peak diastolic blood flow velocities increased from baseline to treatment (63 vs. 76 cm/s; p < 0.001) and diastolic blood flow augmentation was maintained throughout ECP. Peak systolic (87 vs. 78 cm/s; p < 0.001) and end-diastolic velocities (40 vs. 28 cm/s; p < 0.001) decreased significantly, while mean CBFV maintained constant (59 vs. 58 cm/s; not significant). The pulsatility index and resistance index as indirect parameters for peripheral vascular resistance increased during ECP (pulsatility index 0.79 vs. 0.89, p < 0.001; resistance index 0.54 vs. 0.64; p < 0.001). Conclusions: ECP did not increase mean CBFV in healthy subjects even though peak diastolic CBFV were significantly augmented. Changes in CBFV and transcranial Doppler waveform characteristics suggest that the mean flow of the middle cerebral artery is maintained stable via cerebrovascular autoregulatory mechanisms.

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Is Counterpulsation a Potential Therapy for Ischemic Stroke?

Cited by 23 publications

References 93 publications

Intracranial Pressure Elevation after Ischemic Stroke in Rats: Cerebral Edema is Not the Only Cause, and Short-Duration Mild Hypothermia is a Highly Effective Preventive Therapy

Intracranial Pressure Elevation after Ischemic Stroke in Rats: Cerebral Edema is Not the Only Cause, and Short-Duration Mild Hypothermia is a Highly Effective Preventive Therapy

External Counterpulsation Augments Blood Pressure and Cerebral Flow Velocities in Ischemic Stroke Patients With Cerebral Intracranial Large Artery Occlusive Disease

Does External Counterpulsation Augment Mean Cerebral Blood Flow in the Healthy Brain? Effects of External Counterpulsation on Middle Cerebral Artery Flow Velocity and Cerebrovascular Regulatory Response in Healthy Subjects

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