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B Stemper

Publications and source records attributed to B Stemper.

24 records · Page 2Linked to original sources
PubMed1999

Quantitative thermal perception testing in adults.

In 225 adults aged 18 to 80 years, normative warm and cold perception thresholds were assessed at the volar distal forearm, thenar eminence, lower medial calf, and lateral dorsal foot using the method of limits and a Thermotest (Somedic, Stockholm, Sweden). A 1.5-cm x 2.5-cm thermode, a 1 degrees C/s stimulus change rate, and a 32 degrees C baseline temperature were applied. Thresholds of five consecutive stimuli were averaged. At the thenar eminence a 3 degrees C/s stimulation was applied in addition to the 1 degree C/s stimulation. Effects of spatial summation were studied at the calf and forearm by additional testing with a 2.5-cm x 5.0-cm thermode. To evaluate the influence of skin temperature, thresholds were correlated with the pretest skin temperature at the tested sites. Reproducibility of stimulus perception was determined by comparing the lowest to the highest response to five consecutive stimuli. Results showed sufficient accuracy of thermal perception thresholds. Thresholds were higher with the 3 degrees C/s stimulation than with the 1 degree C/s stimulation. Thresholds were lower with the large than with the small probe. Skin temperature had only minimal influence on thresholds. The use of a 32 degrees C baseline temperature and a 1 degree C/s stimulus change rate is recommended. The large probe should be used at body sites where the entire thermode surface adjusts planely to the skin. Warming up the tested skin area is not necessary before thermotesting.

Adolescent↗
PubMed1999

Cold face test demonstrates parasympathetic cardiac dysfunction in familial dysautonomia.

In familial dysautonomia (FD), i.e., Riley-Day syndrome, parasympathetic dysfunction has not been sufficiently evaluated. The cold face test is a noninvasive method of activating trigeminal brain stem cardiovagal and sympathetic pathways and can be performed in patients with limited cooperation. We performed cold face tests in 11 FD patients and 15 controls. For 60 s, cold compresses (0-1 degrees C) were applied to the cheeks and forehead while we monitored heart rate, respiration, beat-to-beat radial artery blood pressure, and laser-Doppler skin blood flow at the first toe pulp. From these measurements heart rate variability parameters were calculated: root mean square of successive differences (RMSSD), coefficient of variation (CV), low- and high-frequency (LF and HF, respectively) power spectra of the electrocardiogram, and the LF transfer function gain between blood pressure and heart rate. All patients perceived cold stimulation and acknowledged discomfort. In controls, heart rate and skin blood flow decreased significantly during cold face test; in patients, both parameters decreased only briefly and not significantly. In controls, blood pressure, RMSSD, CV, and heart rate HF-power spectra increased but remained unchanged in patients. Respiration, as well as heart rate LF power spectra, did not change in either group. In controls, LF transfer function gain between blood pressure and heart rate indicated that bradycardia was not secondary to blood pressure increase. We conclude that the cold face test demonstrated that patients with FD have a reduced cardiac parasympathetic response, which implies efferent parasympathetic dysfunction.

Adolescent↗
PubMed1998

Quantitative thermal perception testing in 225 children and juveniles.

Quantitative Thermotesting evaluates peripheral small nerve fiber function. The method of limits is a widely used algorithm of perception threshold determination. Normative data are needed to apply the method of limits in children and juveniles. In 225 healthy boys and girls, aged 7 to 17.9 years, warm and cold perception thresholds were established with the method of limits at the volar distal forearm, the thenar eminence, the lower medial calf, the lateral dorsal foot, and the cheek. A 1 degree C/s stimulus velocity, a 32 degrees C thermode baseline, and a 1.5-cm x 2.5-cm Thermotest stimulator were used. Accuracy of stimulus perception was studied by comparing the lowest to the highest response of five consecutive stimuli. The influence of different stimulator sizes on thresholds was tested at the lower calf and distal forearm with an additional 2.5-cm x 5.0-cm thermode. To determine the impact of the pretest skin temperature on thresholds, skin temperature was correlated with thresholds. Results showed good intratrial reproducibility of thresholds. The large thermode yielded lower thresholds than the small probe. Skin temperature had only minor influence on thresholds. The large probe should be used at body sites where it adjusts planely.

Adolescent↗
PubMed1998

Highly abnormal thermotests in familial dysautonomia suggest increased cardiac autonomic risk.

OBJECTIVE: Patients with familial dysautonomia have an increased risk of sudden death. In some patients with familial dysautonomia, sympathetic cardiac dysfunction is indicated by prolongation of corrected QT (QTc) interval, especially during stress tests. As many patients do not tolerate physical stress, additional indices are needed to predict autonomic risk. In familial dysautonomia there is a reduction of both sympathetic neurons and peripheral small nerve fibres which mediate temperature perception. Consequently, quantitative thermal perception test results might correlate with QTc values. If this assumption is correct, quantitative thermotesting could contribute to predicting increased autonomic risk. METHODS: To test this hypothesis, QTc intervals were determined in 12 male and eight female patients with familial dysautonomia, aged 10 to 41 years (mean 21.7 (SD 10.1) years), in supine and erect positions and postexercise and correlated with warm and cold perception thresholds assessed at six body sites using a Thermotest. RESULTS: Due to orthostatic presyncope, six patients were unable to undergo erect and postexercise QTc interval assessment. The QTc interval was prolonged (>440 ms) in two patients when supine and in two additional patients when erect and postexercise. Supine QTc intervals correlated significantly with thermal threshold values at the six body sites and with the number of sites with abnormal thermal perception (Spearman's rank correlation p<0.05). Abnormal Thermotest results were more frequent in the four patients with QTc prolongation and the six patients with intolerance to stress tests. CONCLUSION: The results suggest that impaired thermal perception correlates with cardiac sympathetic dysfunction in patients with familial dysautonomia. Thus thermotesting may provide an alternative, albeit indirect, means of assessing sympathetic dysfunction in autonomic disorders.

Adolescent↗
PubMed1995

Vibrameter testing facilitates the diagnosis of uremic and alcoholic polyneuropathy.

The diagnostic sensitivity of Vibrameter and tuning fork examination towards uremic and alcoholic neuropathy was tested in 75 patients. In 40 uremic and 35 alcoholic patients, we compared the sensitivity of neurological examination, nerve conduction studies (NCS) and vibration thresholds assessed at the malleoli by means of Vibrameter and scaled tuning fork. Vibrameter results were correlated with NCS. Polyneuropathy was diagnosed in 52 patients, but in 16 patients diagnosis depended upon inclusion of Vibrameter testing in the examination protocol. In uremic patients, Vibrameter (47.5%) showed abnormalities as often as NCS (45%), and more often than clinical (32.5%) or tuning fork examination (2.5%). In alcoholic patients, Vibrameter revealed abnormalities more often (60%) than NCS (34.3%) or tuning fork (14.3%). Correlations between NCS and vibratory thresholds were low (-0.52 < or = Rs < or = -0.35). Vibrameter studies are far more sensitive than tuning fork tests. The technique complements NCS and refines the diagnosis of uremic and alcoholic neuropathies.

Adult↗