Autonomic function testing

1.Heart rate variability

How is the examination performed?

First, you lie in a relaxed atmosphere on the tilting table. We register the circulatory values with an automatic sphygmomanometer and an ECG. Once the body has become accustomed to the conditions of rest, we will ask you to breathe in a predetermined rhythm. For this you will be given exact instructions. Afterwards it will be necessary to squeeze as much air as possible from the lungs through a mouthpiece.

2. Autonomic function testing

How is the examination performed?

First, you lie in a relaxed atmosphere on the tilting table. We register the circulatory values with an automatic sphygmomanometer and an ECG. Once the body has become accustomed to the conditions of rest, we will ask you to breathe in a predetermined rhythm. For this you will be given exact instructions. Afterwards it will be necessary to squeeze as much air as possible from the lungs through a mouthpiece.

Norepinephrine lab test:

Some circulatory disorders include changes in plasma noradrenaline between lying and standing. A slight increase in the level of stress hormone while standing is normal. For special questions, the plasma norepinephrine level is examined while lying down and standing. This information helps, for example, in the diagnosis of causes and treatment of circulatory disorder. Occasionally there is a very strong pulse and norepinephrine rise while standing in the context of circulatory disorders. In contrast, certain forms of Parkinson's disease have a particularly low noradrenaline level. The blood is drawn under standardized conditions (fasting without medication or previous alcohol / caffeine consumption). The examination takes about 15-30 minutes.

3. Sudoscan

The sudoscan gives us an important brief information about the sweat gland function (sudomotor function). The test lasts only about 5 minutes and allows a screening of the function of so-called small fibers in the skin. Small Fibers is the name that summarizes all unmyelinated and myelin-deficient nerve fibers. With the sudoscan, the sudomotor nerve fibers are electrically stimulated, which transmit signals to the sweat glands. For this, hands and feet are placed on the contact surfaces of the device. In response to a single, barely noticeable electrical stimulus on the skin surface, the sweat glands receive the signal to release sweat. The resulting minor change in skin moisture is registered as a skin resistance change by the device. The test provides an overview of whether the sudomotor nerve function deviates from the norm, how pronounced the deviation is, and whether side differences exist in the function of these small fibers.
With a further development of the stimulation method, the EzScan, a prediction can be made of the risk of developing a metabolic, eg diabetic polyneuropathy, in the coming years.

4. Quantitative Sensitivity Test (QST)

The purpose of this test is to investigate the function of slow-conducting, non-myelinated small fiber nerves. These mediate vibration, pain and temperature stimuli and control the functions of vegetative organs (eg circulation, bladder, gastrointestinal tract, sweat glands). By determining the lower sensory threshold of various stimuli qualities, that is, when a stimulus is just perceived, it can be assessed whether a malfunction of the Small Fibers is present. The comparison of the results for different stimuli helps to localize the damage in the tissue, spinal cord or brain. The examination is standardized, takes about 45-60 minutes and is not invasive.

5. Quantitative Sudomotor Axon Reflex - Test (QSART)

The purpose of this test is to investigate the function of slow-conducting, non-myelinated small fiber nerves that control sweat gland function. Since the test measures the change in skin moisture, it also provides information about the performance of the sweat glands at the examined body site. It can be under-and over-functions that hypohidrosis and hyperhidrosis (as in excessive sweating) capture. Since the sweat gland function with the QSART can be detected at up to four body regions at the same time, the comparison between arms and legs or the comparison between right and left side of the body is easily possible. In contrast to galvanic examination methods, the test response in the Quantitative Sudomotor Axon Reflex Test is triggered by the natural messenger acetylcholine. This is applied to up to four skin areas. In order to be able to measure the resulting moisture at the corresponding parts of the body, small measuring chambers are positioned before the start of the test.

6. Sympathetic skin response

When examining the sympathetic or also the galvanic skin response, it does not result in stimulus responses after application, for example, of an electrical skin irritation not only along the nerve tracts in the corresponding skin area but also to changes in electrical skin resistance in almost all other body regions. These electrical voltage changes are well measurable, especially in regions with high sweat gland density, such as on the palms and soles of the feet. Test duration about 15 to 30 min.