What do spikes in EEG mean?
Spikes or sharp waves are terms commonly seen in EEG reports. If these happen only once in a while or at certain times of day, they may not mean anything. If they happen frequently or are found in specific areas of the brain, it could mean there is potentially an area of seizure activity nearby.
What does a focal seizure look like on an EEG?
When a seizure happens during an EEG, the normal pattern of brain activity that is seen on the EEG reading changes, and different brain activity can be seen. In focal seizures the change in brain activity can be seen only on the electrodes on the part of the brain the seizure is happening in.
What is an abnormal variant in EEG?
The phrases “electroencephalogram (EEG) variant waves” or “normal EEG variants” refer to waves that are rare or unusual but not generally abnormal. They may be unusual in shape or in distribution. These variant waveforms include waveforms and patterns that are rare or unusual but are known to be generally benign.
How long do temporal lobe seizures last?
Sometimes temporal lobe seizures impair your ability to respond to others. This type of temporal lobe seizure usually lasts 30 seconds to two minutes. Characteristic signs and symptoms include: Loss of awareness of surroundings.
What is midline theta rhythm?
The midline theta rhythm consists of runs of theta waves occurring in the midline, especially in the central and parietal vertex regions. Few reports regarding this uncommon EEG finding have been published. It has been given various names, e.g. theta discharges in the middle-line, theta spindles, etc.
What causes slowing on EEG?
The slowing can be high or low amplitude. Several etiologies can cause diffuse slowing, including sedative medications, metabolic encephalopathy, toxic encephalopathy, cerebral infections like meningoencephalitis, or deep midline brainstem structural lesions.
Does an EEG show brain death?
Electroencephalography (EEG) is frequently used to assist the diagnosis of brain death.
What is sleep deprived EEG?
A sleep-deprived EEG, or an electroencephalogram, is a type of EEG that requires the patient to acquire less sleep than usual before undergoing the test.
What is rhythmic mid-temporal Theta of drowsiness?
Another example of EEG having very aptly named findings, rhythmic mid-temporal theta of drowsiness (RMT) is seen as sharply contoured, rhythmic theta activity restricted to the temporal regions; it is usually quite short, only a second or so.
What are theta rhythms in psychology?
Theta rhythms are commonly encountered in the frontocentral regions and are usually related to drowsiness or heightened emotional states. In the past, theta rhythms were associated with a variety of clinical conditions, including epilepsy, but their common occurrence is now better appreciated as a normal variant.
What is Delta slowing theta rhythm?
Theta and Delta Slowing Theta rhythms are commonly encountered in the frontocentral regions and are usually related to drowsiness or heightened emotional states. In the past, theta rhythms were associated with a variety of clinical conditions, including epilepsy, but their common occurrence is now better appreciated as a normal variant.
What is frontal midline theta rhythm?
This theta activity was a train of rhythmic waves at a frequency of 6–7 Hz with maximum amplitude around the frontal midline and was labeled as the frontal midline theta rhythm. The frontal midline theta rhythm is often associated with the hippocampal theta rhythms.