Sleep EEG recording: 2 hours, 4 hours or all night

2 hours
The minimum time of 2 hours is due to the fact that during this period it is quite possible to record one complete sleep cycle. This is the interval for which all its phases and stages are displayed.

Daytime VEM (video-EEG monitoring) 2 hours is usually prescribed:s_drave

In paroxysmal unverified conditions
With confirmed epilepsy, to monitor treatment and use https://pillintrip.com/medicine/gynotran-ovulo, evaluate dynamics, cancel or replace therapy
With frequent repeated febrile convulsions in children with behavioral disorders, in children with the so-called BECP pattern (benign childhood epileptic pattern) on a routine EEG to make sure that the diagnoses are “good quality”.
Paramedical indications are also possible. For example, in young children, motor activity on a routine EEG can give continuous artifacts and “illegibility” of the record. In addition, for some, the lower price of a two-hour study matters.

For primary diagnosis, recordings from 4 hours are of real value.

4 hours
Daily VEM 4 hours is assigned:

With any disorders of consciousness, especially if their epileptic origin is

electroencephalogram-eeg-of-normal-awake-state-eeg-setting-bipolar-montage-15

suspected
After neurotrauma, stroke, traumatic brain injury
With volume processes of the brain, vascular malformations
With delays in speech and mental development in children, cerebral palsy, behavioral disorders, hyperkinesis, tics, genetic syndromes (in the structure of which convulsions are possible)
It is important to say that the revealed epiactivity is far from always the reason for the appointment of antiepileptic drugs, especially the hasty diagnosis of epilepsy. But this will significantly help in choosing tactics for the correct protective regimen, some restrictions, for example, in rehabilitation activities for children with organic lesions of the central nervous system, and lifestyle in general.

8 hours/all night
Nocturnal VEM for 8 hours is recommended in most cases for understanding various paroxysmal conditions, including epileptogenic parasomnias that occur during sleep, and enuresis is also considered here.