Diabetic Neuropathy and Axon Reflex-Mediated Neurogenic Vasodilatation in Type 1 Diabetes

Objective: Axon reflex-mediated neurogenic vasodilatation in response to cutaneous heating may reflect early, pre-clinical small fibre dysfunction. We aimed to evaluate the distribution of the vascular flare area measured by laser doppler imaging (‘‘LDI FLARE area’’) in type 1 diabetes and in healthy volunteers. Research and Methods: Concurrent with clinical and electrophysiological examination to classify diabetic sensorimotor polyneuropathy (DSP), LDIFLARE area (cm 2) was determined in 89 type 1 diabetes subjects matched to 64 healthy volunteers. We examined the association and diagnostic performance of LDI with clinical and subclinical measures of DSP and its severity. Results: Compared to the 64 healthy volunteers, the 56 diabetes controls without DSP had significantly lower LDIFLARE area (p = 0.006). The 33 diabetes cases with DSP had substantially lower LDIFLARE area as compared to controls without DSP (p = 0.002). There was considerable overlap in LDIFLARE area between all groups such that the ROC curve had an AUC of 0.72 and optimal sensitivity of 70 % for the detection of clinical DSP. Use of a subclinical definition for DSP, according to subclinical sural nerve impairment, was associated with improved AUC of 0.75 and sensitivity of 79%. In multivariate analysis higher HbA1c and body mass index had independent associations with smaller LDIFLARE area. Conclusions: Axon reflex-mediated neurogenic vasodilatation in response to cutaneous heating is a biomarker of earl

Thermography after subcutaneous mastectomy and reconstruction with silicone gel prosthesis: a pilot study

Patients with subcutaneously placed silicone gel prostheses, for reconstruction after subcutaneous mastectomies, often complain of cold breasts as well as of slow regaining of warmth after cooling. We have used thermography in 7 such women and in 7 healthy women of the same age group as controls. Thermography has also been used in 3 women after repositioning of the subcutaneously placed prostheses to a submuscular position in order to study any possible changes in temperature. In 2 cases thermography also was found to aid in the diagnosis of a suspected subcutaneous displacement of a submuscular prosthesis; the technique has an advantage over mammographic examination, since thermography is a simple, less expensive, and safer method

Effect of local cold provocation on systolic blood pressure and skin blood flow in the finger

Demonstration of increased vascular cold reactivity in patients with Raynaud's syndrome is difficult. For medico-legal reasons, it is important to get objective measures of vasospasm in these patients. Evaluation of the degree of vasospasm also provides prognostic information which is useful for patient management. In this study, we compare two methods of arterial circulation measurement. The laser Doppler scanning is a new method, which uses the recently developed laser Doppler perfusion imaging (LDPI) instrument. The aim of the present study was to compare the effect on finger skin blood flow measured with LDPI with changes in finger systolic blood pressure during local cold provocation. The effect of such provocation, skin blood flow and systolic blood pressure, were studied in 15 healthy controls. Six patients with known traumatic vasospastic disease (TVD) were also tested with both methods. Finger skin blood flow was measured with LDPI on the distal phalanx of the index finger of the left hand, every minutes during 6 min of local heating at 40 degrees C followed by local cooling for 3 min at 15 degrees C and then for 3 min at 10 degrees C. Finger systolic blood pressure was measured with strain-gauge method before and after local cooling to 10 degrees C with a cuff perfused with water of desired temperature. The test was performed in the same finger within a week of the laser Doppler scanning. Local finger cooling to 15 degrees C and 10 degrees C caused a significant decrease in blood flow, most marked at 10 degrees C. There was, however, no correlation between the decrease in blood flow and blood pressure. In the TVD-patients decreases in skin blood flow were similar compared with the healthy controls. In contrast, the changes in systolic blood pressure, were outside normal range (systolic quotient <0.65) in five of the six patients (83%), and also in 11 of the 15 healthy controls (73%). In conclusion, there is no correlation between the decrease in finger skin blood flow and systolic blood pressure during local cold provocation. For diagnosis of traumatic vasospastic disease (TVD), local cold-induced changes in finger systolic blood pressure seems superior to changes in skin blood flow, but the ideal clinical method for demonstrating increased cold-induced vasospasm is, however, still lacking

Sympathetic dysfunction in patients with primary Sjogren's syndrome

OBJECTIVE: To investigate autonomic nervous system function in patients with primary Sjogren's syndrome (SS) and relate the findings to clinical variables. METHODS: Autonomic nervous system function was determined in 30 patients with primary SS using the finger skin blood flow test [vasoconstrictory (VAC) index], deep-breathing test [expiration/inspiration (E/I) ratio], and the tilt table (orthostatic) test [acceleration index (AI), brake index (BI), and orthostatic blood pressure]. The results were compared with age matched control materials (finger skin blood flow test, n = 80, and deep-breathing and tilt table tests, n = 56). RESULTS: The VAC index was found to be significantly increased and the E/I ratio significantly decreased in patients compared to controls, indicating both a sympathetic and a parasympathetic dysfunction. Further, the patients, especially the anti-SSA and anti-SSB antibody seropositives, were found to have an abnormal blood pressure reaction to tilt compared to controls. No correlations were found between autonomic nerve function variables measured and the clinical ophthalmologic or the oral tests, performed at the time of diagnosis. CONCLUSION: Patients with primary SS show signs of both sympathetic and parasympathetic dysfunction. Further, immunological mechanisms seem to influence blood pressure in patients with primary SS

Sympathetic skin vasoconstriction--further evaluation using laser Doppler techniques

The aim of this study was to quantify the reflex sympathetic vasoconstriction in skin at different depths. Twenty healthy subjects were studied. Finger skin blood flow was measured using laser Doppler perfusion imaging (LDPI) and laser Doppler perfusion monitoring (LDPM). In LDPM, a probe with fibres separated 0.25 mm (deep) and 0.14 mm (superficial) from the illuminating fibre was used. Local heating (40 degrees C) was achieved with a Peltier element, and reflex vasoconstriction induced by immersion of the contra-lateral hand and forearm for 3 min in water at 15 degrees C. The change in skin blood flow was measured and a vasoconstriction index (VAC: cooling/before cooling) calculated. VAC indices of LDPI, LDPM-0.25 and LDPM-0.14 were 0.60, 0.59 and 0.60, respectively. The two components of the LDPM perfusion value, blood cell velocity and concentration, were studied separately. Their contributions in LDPM-0.25 were roughly the same, whereas the velocity component dominated in LDPM-0.14, although their relative responses in the two channels were similar. We conclude that sympathetic skin vasoconstriction does not significantly differ in two compartments, as probed with fibres separated by 0.25 and 0.14 mm. Blood cell velocity is influenced in a proportional way, as is concentration