Rheoencephalography (REG) is a non-invasive method of investigating fluctuations in the volume of blood filling of the cerebral vessels and neck vessels, based on the graphic recording of synchronous pulse changes in impedance between electrodes placed on the scalp.
With rheoencephalography can judge the tone and elasticity of the cerebral and neck vessels, blood viscosity, pulse wave velocity, flow velocity, assess latency periods, the time course and severity of regional vascular reactions.
Indications for rheoencephalography
Rheoencephalography of the brain and neck vessels used by physicians in the diagnosis of the following diseases:
- Ischemic stroke, cerebral ischemia
- Vertebrobasilar insufficiency (VBI) with vertigo symptom
- Somatoform autonomic dysfunction
- Ischemic brain disease
- Dizziness, stuffiness in ear and tinnitus
- Increased intracranial pressure and hydrocephalus
- Headache, migraine
- Traumatic brain injury (concussion, contusion, brain hemorrhage, axonal shearing lesions)
- Cervicocranial syndrome and whiplash neck injury
- Parkinson's disease
- Pituitary microadenoma, macroadenoma and nonfunctioning adenomas (NFPAs), hyperprolactinemia syndrome
The physical basis the method of rheoencephalography is the difference between the electrical conductivity of blood and tissues of the body, and therefore the pulse fluctuations in blood supply caused primarily fluctuations conductivity of the test site. Since the detection of the pulse changes the electrical conductivity is only possible by passing through the fabric weak (2-2.5 A) high-frequency (100-200 kHz) the current common element for all types of rheograph a high-frequency generator.
Plate electrodes for rheoencephalography are coated with a thin layer of paste is applied to contact corresponding portions of the scalp, degreased with alcohol. At the most common frontomastoidalnom abduction rheoencephalography, one electrode is applied on the inner edge of the eyebrows, the other - on the mastoid.
To evaluate hemodynamics in the vertebral arteries using occipital-mastoid leads. As functional loads using hyperventilation (1-2 min), breath holding, inhalation of carbon dioxide, various (vasodilator and vasoconstrictor) pharmacological agents, orthostatic test, and to identify the extent of collateral circulation use alternate compression of the carotid or vertebral arteries.
An increase in vascular tone in the rheoencephalography increased pulse rise time curve, flattened top, additional waves disappear. The decrease of vascular tone is characterized by shortening the distance between the Q wave on the electrocardiogram and the beginning of the wave, the decrease rising time of the waves, pointed peaks in the presence of 2-3 additional waves on the descending part of the curve.
At reoentsefalogramm dynamic studies in patients with head injury, accompanied by subarachnoid hemorrhage, ranging from 4-5-x d. after injury, often marked increase in tone and pulse volume reduction of cerebral blood vessels in the normalization of these indicators on the 20-30th day. Please note that rates rheoencephalography may reflect fluctuations in blood supply to the scalp blood vessels that cause difficulty in the interpretation of results.