Eugene Kosh
you probably never go out in the woods.
Walking through the woods on a Sunny day - shimmering flash.
and if not the bike is even better.
and you have a car ever went .. at least not the driver and passenger?? along the woods.. or groves.. at sunset.. when the sun is at the side - just ... and if the grove or forest close to the road(highway).. and even before and after lunch - a solid flash ( when the sun is sideways from the direction of movement)... (the trees provide shade and the spaces between the trees - quite clearly because the sun shines Smile
so solid flash.. what to do ? ride only at night? Smile))
PHOTOSENSITIVE EPILEPSY
Even in Ancient Rome, the slave market used the rotation of the Potter's wheel, rhythmically reflecting the sunlight, for revealing they have epilepsy. In 1934, ADRIAN and MAITHEWS installed the impact on human light flashes at the frequency of the alpha rhythm (8-12 Hz). In the future WANER (1946, 1949, 1951) studied in detail the influence of light flashes on people. It was noted that there was a reaction to photostimulation at
3-4% healthy of study in the form of dizziness or nausea, and in some cases numbness or a short disturbance of consciousness (
the transition to the ISS). Currently, the technique of photostimulation is used only in conjunction with electroencephalography (EEG).
PHOTOSENSITIVE EPILEPSY
S. I. Fomichev
Photosensitive (photosensitive) epilepsy is a condition in which a flickering light
high intensity causes epileptic seizures. It is sometimes called reflex epilepsy. Among people with epileptic seizures only
2-5% marked photosensitive seizures. Recently appeared information about the increase in cases of seizures that is associated with a massive passion for video games.
The prevalence of photosensitive epilepsy also depends on nationality and hereditary predisposition. Photosensitive epilepsy is particularly common in children aged 9 to 15 years. Rarely a first attack up to 5 years or after 20 years. Girls such attacks occur more frequently than in boys. The most frequent large seizures (tonic-clonic and tonic), absence seizures and myoclonia.
THE CONDITIONS OF THE STUDY
You must fulfill the following conditions in conducting EEG studies on photosensitivity:
- the study is conducted with closed eyes studied;
- distance from the light source to the eyes of 25-30 cm;
-
intensity the lights should be
maximum for this apparatus;
- the frequency of the light flashes, provoking epileptic activity depends on age and is located in the border of 5-30 flashes per second (the older the child, the greater the frequency of flashes is necessary to provoke change);
- frequency of light flashes is changed smoothly or in increments of 5 flashes every 10 seconds;
- photostimulation is carried out twice - before and after
hyperventilation.
The identification of photosensitivity also
contributes to sleep deprivation for 24 hours. When assessing the results of the study should be aware that photic stimulation induces epileptic changes on EEG in approximately
2% of people in the populationand they are found
genetic predisposition to such changes.
INTERPRETATION OF CHANGES
There are the following four groups of paroxysmal changes in the electroencephalogram:
1. bilaterally synchronous, high-amplitude, slow-wave activity, primarily in fronto-Central or occipital leads with generalized spikes and sharp waves or complexes peak-wave;
2. photoconversion effect with a fronto-prezentului complexes polipek-wave;
3. photobiologically effect (muscle tension in the head and neck with EMG and spycapture phenomena on EEG);
4. bilateral parieto-occipital slow waves.
Illustration - 32 kb - Generalized epileptic activity during photostimulation.
(where is the link?)
These changes often occur in people with epileptic seizures. However, it should be noted that myoclonic effect of photostimulation, as well as mastering the rhythm of the light flashes and bilateral slow waves in occipital leads can occur with non-epileptic diseases: hysteria, migraine, syncope conditions, cerebrovascular disorders, diencephalic pathology, etc.
In any case, the photosensitive detecting changes in EEG in healthy people should be very careful to treat their clinical interpretation.
There are two groups of photosensitive epilepsy with epileptic activity on EEG:
1. true photosensitive epilepsy (9% of epileptics) with the appearance of seizures, usually tonic-clonic, only when exposed to flashes of light;
2. epilepsy with photosensitivity in which photic stimulation induces changes on the EEG but the seizures can occur spontaneously.
The presence of a generalized paroxysmal activity during photostimulation helps in the differential diagnosis vereceklerini generalized and partial seizures.
Traumatic Genesis of epileptic seizures photostimulation practically does not cause changes.
Interesting material. Please add specific links, as expected. (Emphasis in red is mine - A. Patrushev)<