The Effect of Enhanced External Counterpulsation on Regional Cerebral Blood Flow in Patients with Cerebral Arteriosclerosis Without Cerebral Infarction
Author Information and Affiliation
Xu Zhongbang, Yang Liangming
The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
Source: usecp.com (Compiled and reviewed by Gong Guoji)
Abstract
Background: Enhanced External Counterpulsation (ECP) has been shown to improve cerebral rheoencephalographic parameters. To further investigate the effect of ECP on regional cerebral blood flow (rCBF), we observed the changes in rCBF before and after ECP in a group of patients with cerebral arteriosclerosis but without cerebral infarction, using Single-Photon Emission Computed Tomography (SPECT).
Methods: This study enrolled 22 hospitalized patients (16 males, 6 females; mean age 61.9±8.1 years) diagnosed with cerebral arteriosclerosis and confirmed to be free of cerebral infarction by clinical assessment and head CT scans. rCBF was measured using a Siemens ZLC3700 SPECT device with 99mTc-ECD (740 MBq dose) as the radiotracer under resting conditions. Each patient underwent SPECT scanning before the initiation of ECP treatment and after completing 36 sessions of ECP. ECP was administered using a USECP device once daily for 60 minutes per session.
Results: Before ECP treatment, a total of 65 regions of reduced rCBF were detected across the 22 patients, averaging 2.9±1.3 regions per patient. The reduced rCBF areas were predominantly found in the frontal, parietal, and occipital lobes.
- Patient Level: 10 patients (45.4%) showed a return to normal cerebral blood flow; 8 patients (36.4%) showed improvement in cerebral blood supply. The total effective rate was 18 patients (81.8%). Four patients (18.2%) showed no improvement in rCBF.
- Regional Level: Among the 65 reduced rCBF regions, 30 regions (46.2%) returned to normal; 22 regions (33.8%) showed improvement; and 13 regions (20.0%) showed essentially no change.
Conclusion: ECP treatment effectively improves reduced regional cerebral blood flow in patients with cerebral arteriosclerosis without cerebral infarction. ECP may improve local blood supply in ischemic areas by increasing the diastolic perfusion pressure and blood flow to the brachiocephalic arterial system, potentially playing a role in preventing or mitigating the occurrence of ischemic stroke.
Methods
1. Study Participants
A total of 22 hospitalized patients with cerebral arteriosclerosis were enrolled, including 16 males and 6 females. Their ages ranged from 40 to 72 years, with a mean age of 61.9±8.1 years.
The diagnosis of cerebral arteriosclerosis was based on the criteria established at the Second National Academic Conference of Neuropsychiatry in 1978, and cerebral infarction was excluded by clinical assessment and head computed tomography (CT) scans.
Clinical Manifestations
- Dizziness/Vertigo: 21 cases
- Headache: 6 cases
- Head spinning/Lightheadedness: 10 cases
- Transient Ischemic Attack (TIA): 10 cases (Vertebrobasilar system: 6 cases; Carotid system: 4 cases)
- Hypertension: 12 cases
- Hypercholesterolemia: 7 cases
- Hypertriglyceridemia: 15 cases
2. Regional Cerebral Blood Flow (rCBF) Measurement
Equipment and Radiotracer: A Siemens ZLC3700 SPECT device was used. The radiotracer was 99mTc-ECD at a dose of 740 MBq, administered intravenously while the patient was in a resting state. Brain tomography scans were performed 30 minutes post-injection, and the transverse, coronal, and sagittal images of the brain were reconstructed.
Procedure: rCBF was measured once before the ECP treatment and once after its completion, using the same conditions and methods to compare the changes in rCBF in the corresponding brain regions.
3. Enhanced External Counterpulsation (ECP) Treatment
Device and Protocol: The USECP Enhanced External Counterpulsation device was used according to standard operating procedures. Treatment was administered once daily for 60 minutes per session. Each patient completed a total of 36 ECP sessions before the post-treatment rCBF measurement.
Results
1. Distribution of Reduced rCBF Regions Before ECP
Before ECP treatment, a total of 65 regions of reduced rCBF were detected in the 22 patients. The distribution of these reduced rCBF areas is presented in Table 1.
Table 1. Distribution of Reduced rCBF Regions Before ECP (N=65)
| Brain Lobe | Left Side (n) | Right Side (n) | Total (n) |
|---|---|---|---|
| Frontal Lobe | 8 | 7 | 15 |
| Temporal Lobe | 4 | 6 | 10 |
| Parietal Lobe | 12 | 6 | 18 |
| Occipital Lobe | 10 | 7 | 17 |
| Basal Ganglia Area | 3 | 2 | 5 |
Table 2. Distribution of Reduced rCBF Regions Across Patients
| Number of Reduced rCBF Regions per Patient | Number of Patients (n) |
|---|---|
| 1 region | 2 |
| 2 regions | 8 |
| 3 regions | 7 |
| 4 regions | 3 |
| 6 regions | 2 |
The average number of reduced rCBF regions per patient was 2.9±1.3.
2. ECP Treatment Efficacy
Efficacy at the Patient Level (N=22)
| Outcome | Number of Patients (n) | Percentage (%) |
|---|---|---|
| Cerebral blood flow returned to normal | 10 | 45.4 |
| Cerebral blood supply improved | 8 | 36.4 |
| Total Effective Rate | 18 | 81.8 |
| No improvement in rCBF | 4 | 18.2 |
Efficacy at the Regional Level (N=65)
Among the 65 regions of reduced rCBF, the post-treatment changes were as follows:
- Returned to normal: 30 regions (46.2%)
- Improved: 22 regions (33.8%)
- Essentially unchanged: 13 regions (20.0%)
Discussion
Cerebral arteriosclerosis, a key underlying pathology, can be broadly categorized into large artery (15∼60 mm diameter) and small artery (2∼14 mm diameter) hardening. The former is mainly related to atherosclerosis, while the latter is often associated with hypertension and senile arterial wall degeneration. Both conditions lead to luminal narrowing, reduced wall compliance, and decreased blood flow. Our previous observations indicated that 60% of patients with cerebral arteriosclerosis (without infarction) and 85% of patients with TIA exhibited reduced rCBF, with some of these patients developing cerebral infarction within a short period. Therefore, timely and effective treatment to enhance cerebral blood supply and improve cerebral circulation in patients with reduced rCBF who have not yet developed complications is crucial for preventing cerebral infarction.
The mechanism of ECP involves increasing the aortic diastolic pressure. This action not only enhances diastolic perfusion to the coronary arteries but also elevates the diastolic pressure of the brachiocephalic arterial system (including the carotid arteries) originating from the aortic arch, thereby increasing cerebral blood perfusion. Both animal experiments and clinical studies have confirmed that ECP can increase carotid artery blood flow.
In the present study, 22 patients with cerebral arteriosclerosis without cerebral infarction exhibited varying degrees of reduced rCBF. After 36 sessions of ECP, 45.4% of the patients (corresponding to 46.2% of the ischemic regions) showed a return to normal cerebral blood flow, and 36.4% of the patients (corresponding to 33.8% of the ischemic regions) showed improved cerebral blood supply, resulting in a total effective rate of 81.8%. This result suggests that ECP not only increases the overall blood flow to the brachiocephalic arterial group but, more importantly, directly improves the local blood supply to the ischemic areas, normalizing rCBF or mitigating the degree of ischemia. For patients with reduced rCBF, ECP may play a protective role in preventing or lessening the occurrence of ischemic stroke.