Sympathetic Vasomotor Response of the Radial Artery in Patients With Diabetic Foot Syndrome

Abstract

ANJA VICTOR, BS 5OBJECTIVE -Neurophysiological assessment of the peripheral autonomic system is characterized by various limitations. An alternative approach to laser Doppler and venous plethymography is the assessment of the sympathetic vasomotor response of the radial artery obtained by continuous wave Doppler sonography. Nomogram data have been established and demonstrate the temporary disappearance of diastolic flow after coughing or deep inspiration. RESEARCH DESIGN AND METHODS -We assessed the sympathetic vasomotor response in 25 patients (mean age 64 years, range 43-76) with diabetic foot syndrome. The Doppler data were correlated with nerve conduction studies of the median and peroneal nerve, the extent of radiologically diagnosed media sclerosis, and compared with nomogram values (n ϭ 41).RESULTS -Although similar mean flow velocities were found under baseline conditions, the flow pattern was characterized by higher pulsatility in the diabetic group (resistance index [RI] 1.1 vs. 0.7). No significant difference in RI was observed after coughing. The latency of onset of the response was prolonged (2.1 vs. 1.5 s), while the duration of the response did not differ (18 vs. 15 s). Only the nerve conduction velocity of the peroneal nerve correlated inversely with the RI. The extent of radiologically proven calcification tended to correlate with the pulsatility of the baseline signal and the response latencies.CONCLUSIONS -The data obtained by this study suggest the concurrent existence of reduced vessel elasticity due to media sclerosis and dysfunction of the autonomic vasomotor system. Diabetes Care 26:2616 -2621, 2003A utonomic neuropathy is a frequent complication in diabetes and one of the major causes of cardiovascular death. Mortality rates vary from a 60% 5-year mortality (1) to a 10% 10-year mortality (2) and are about three times as high as in patients with neuropathy without clinical evidence of autonomic involvement (3). While extensive tests for cardiovascular autonomic functions are readily available (4,5), they may be of little help in the diagnosis of peripheral autonomic dysfunction (6). To date, laser Doppler flowmetry, which enables assessment of the capillary and arteriovenous blood flow, represents the most reliable test for the diagnosis of peripheral autonomic dysfunction (7-9). This technique can be applied under conditions at rest and during sympathetic stimulation by means of a deep inspiratory gasp (10) or an electric stimulus (9). Alternatively, venous plethysmography (6) and duplex Doppler sonography (11) have been used. These studies have confirmed the hypothesis of a hyperperfusion state in the lower extremities at an arteriovenous shunt volume that was increased up to threefold due to opening of the sympathetically controlled resistance vessels (7,10). Furthermore, other workers reported a reduction in the response to sympathetic stimulation (10,11). In ϳ50% of a cohort of diabetic patients, an abnormal skin blood flow has been observed at the index finger and a nondiscernible d...

Pulsed wave Doppler ultrasonography for the assessment of peripheral vasomotor response in an elderly population

“…In this study, PI increased, while Vmax, Vmin, and TAMaxV decreased in both the young and the older groups after coughing (Table 1 and 2). This finding is consistent with previous studies showing that sympathetic arterial vasoconstriction can be elicited in adults at any age 1, 3, 15. At rest, the vasomotor tone reflected by PI showed no significant difference between the two groups (Tables 1 and 2 and Figure 5).…”

“…The latency of SSR is known to increase significantly with age 14. Although SSR was previously considered to be age‐independent,1, 3, 15 few studies compared the magnitude of this response between young and older people. We therefore designed a study to evaluate the effect of aging on the sympathetic vasomotor response as shown by a change in vascular resistance indirectly reflected in the pulsatility index 16…”

Comparison of continuous wave Doppler ultrasound of the radial artery and laser Doppler flowmetry of the fingertips with sympathetic stimulation

“…Simultaneous comparison of laser Doppler flowmetry of the fingertips and flow changes in the radial arteries in patients with autonomic disorders has yet not been reported. However, our previous data, obtained from patients with a diabetic foot syndrome [5], were in accordance with LDF studies [9]. Both studies showed a decreased sympathetic vasoconstriction due to external stimuli, electrically induced or by cough.…”

“…Nomogram data have been established from our group and demonstrate the temporary disappearance of diastolic flow after coughing or deep inspiration [4,15]. Compared with healthy volunteers, the flow pattern in patients with a diabetic foot syndrome shows a different profile with a bior triphasic flow at baseline indicating a reduced distensibility of the vessel walls and a delayed onset of reaction as evidence of neuropathic damage of the sympathetic fibres [5]. As the flow profile of the radial artery is obtained in a vessel segment proximal to the vascular resistance vessels (i. e. arterioles), these data need to be correlated with LDF, the standard measurement of microcirculatory blood flow.…”

Pulsed Wave Doppler Ultrasound Is Useful to Assess Vasomotor Response in Patients with Multiple System Atrophy and Well Correlated with Tilt Table Study

“…Previous studies using continuous wave Doppler ultrasound to assess SVR in patients with diabetic neuropathy or carpal tunnel syndrome indicated that reduced elevations in pulsatility or resistive index after stimulation implied impairment in the corresponding sympathetic circuits [15, 16]. However, for patients with MSA, the deficit in sympathetic neurotransmission was known to be preganglionic, therefore the indicators for peripheral vasoconstriction like pulsatility index may remain normal as controls [3].…”