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Objective: To establish the normal values of the transcranial doppler sonography in healthy Korean adults according to the increasing age and sex.
Method: We examined 68 healthy adult volunteers who had no history of diabetes mellitus, hypertension, cerebrovascular disease or other neurological illness. The study included 54 subjects from whom good doppler signals from the middle, anterior, and posterior cerebral arteries could be obtained. Mean blood flow velocity (MBFV), Resistance index (RI), and Pulsatility index (PI) were analyzed by Angiodine 2 Doppler System operating at 2 MHz frequency.
Results: MBFV significantly decreased with the increasing age in the middle, anterior and posterior cerebral arteries (p＜0.05). There was a significantly decreased MBFV of the middle cerebral artery in the 4 th, 5 th, 6 th, and 7 th decades compared to the 3 rd decade (p＜0.05). RI and PI were significantly increased with the increasing age (p＜0.05). MBFV of the female subjects were greater than the male subjects (p＞0.05). There was no significant difference in the RI and PI between the male and female subjects.
Conclusion: We suggest that the transcranial doppler sonography can be used as one of the useful screening tools for the diagnosis of cerebrovascular diseases.
The importance of neuropathy in the pathogenesis of foot lesions has been well recognized in diabetes. Blood flow in ischemic limbs has been extensively investigated but the circulation of limbs affected by peripheral neuropathy has received little attention. Some studies on blood flow in peripheral neuropathy have shown a remarkable increase in resting flow, transcutaneous venous oxygen tension, and vascularity, along with loss of the spontaneous variations which occur normally with sympathetic activity of the foot in patients with diabetes. The aim of present study is to find out the effects of somatic and autonomic nervous function in early change of blood flow of foot in diabetic patients. We have studied fifty-one patients of non-insulin-dependent(type II) diabetes with no history of hypertension or diabetic foot ulcers. The evidence of neuropathy was screened by nerve conduction studies and sympathetic skin response of both lower extremities. Blood flow of dorsalis pedis and posterior tibial arteries was measured by portable doppler machine and presented as pressure index (ankle-to-arm systolic pressure ratio). The patients with sympathetic dysfunction showed significant decrease in pressure index compared to normal control and diabetic patients with normal sympathetic function, suggesting that changes of the blood flow occur in diabetic patients with sympathetic dysfunction.
Objectives: To investigate the lower extremity blood flow in hemiplegic patients with a quantitative Doppler ultrasound examination of the common femoral artery(CFA).
Methods: Cross-sectional area(CSA), peak systolic velocity(PSV) and inflow volume(IV) of CFA of normal and paralyzed limbs in 24 hemiplegic patients were measured with a Doppler ultrasound. Patients were divided into three groups according to the ambulation levels: 1) nonambulator, 2) assisted ambulator, and 3) independent ambulator. The results from Doppler images of paralyzed lower extremity were compared with the normal side in each three different groups.
Results: In the nonambulator group, the three parameters were not significantly different between normal and paralyzed lower extremity. In the assisted ambulator group, the CSA of the paralyzed lower extremity was significantly smaller than the normal side (p＜0.05). In the independent ambulator group, the CSA and IV of the paralyzed lower extremity were significantly smaller than the normal side (p＜0.05).
Conclusion: The results of this study proved that the blood flow of the paralyzed lower extremity was diminished than the normal side in hemiplegic patients especially for the independent ambulator group.
Objective: The purpose of this study was to evaluate hemodynamics for diabetes mellitus (DM) by transcranial Doppler sonography (TCD) and to evaluate the influences of risk factors to cerebral hemodynamics in DM.
Method: We examined 54 normal persons, 17 patients with DM without risk factors, and 15 patients with DM and risk factors. The risk factors were hypertension, smoking, and hyper lipidemia (total cholesterol ＞240 mg/dl, low density lipoprotein ＞160 mg/dl). Mean blood flow velocity (MBFV) was also analyzed by Angiodine 2 Doppler system operating at 2 MHz frequency from each subjects.
Results: There was a significant decrease of MBFV in the diabetes in comparison to control groups (p＜0.05). There was a significant decrease of MBFV in the diabetic risk group as compared to diabetic non-risk group (p＜0.05). There was significantly increased total cholesterol, low density lipoprotein, low density lipoprotein/high density lipoprotein ratio in the diabetic risk group as compared to diabetic non-risk group (p＜0.05). MBFV significantly decreased with increasing concentration of HbA1C and duration of DM (p＜0.05).
Conclusion: We suggest that transcranial Doppler sonography can be used as one of the useful screening tests for early detection of cerebrovascular diseases in DM.
Objective: To investigate the changes of cerebral and cardiovascular hemodynamics in response to postural change in tetraplegics after cervical spinal cord injury.
Method: We studied 5 healthy volunteers and 14 cervical cord injured patients with orthostatic hypotension. We continuously monitored heart rate (HR), blood pressure (BP) by volume clamp photoplethysmography, and cerebral blood flow velocity (BFV), pulsatility index (PI) of middle cerebral artery (MCA) by transcranial Doppler sonography at rest and during head-up-tilt (HUT). Tilt table set at 30o initially and then increased gradually 10o every 5 minutes up to 80o.
Results: In the control group, BP and BFV of MCA remained unchanged during HUT. Although a decrease of BFV observed in all patients during both systolic and diastolic phases, the degree of BFV drop during diastolic phase, especially early diastolic phase was much greater than that during systolic phase. The change of BFV of MCA was significantly correlated with that of systemic hemodynamic parameters, especially systolic BP. After rehabilitative therapy for one month, there was no definite evidence of the change in cerebral autoregulation.
Conclusion: This study suggests that we can use systemic hemodynamic parameters for predicting changes of cerebral blood flow in response to orthostatic hypotension, but we fail to observe any compensatory mechanism of cerebrovascular system to maintain cerebral blood flow against systemic hemodynamic collapse.
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