What does it mean when an EEG shows slowing?
Focal Slowing Focal slow wave activity on the EEG is indicative of focal cerebral pathology of the underlying brain region. Slowing may be intermittent or persistent, with more persistent or consistently slower activity generally indicating more severe underlying focal cerebral dysfunction.
What is paroxysmal EEG?
Generalized paroxysmal fast activity (GPFA) is an electroencephalographic (EEG) finding in patients with symptomatic generalized epilepsy consisting of 15–25 Hz frontal predominant generalized fast activity lasting 1–10 s seen predominately in sleep [1].
What is mild diffuse slowing on EEG?
Diffuse slowing: Diffuse slowing indicates global cerebral dysfunction. The slowing can be in the theta or delta ranges. The slowing can be high or low amplitude.
What does temporal slowing mean?
Temporal slowing just means that the brain waves in that area are slower frequency than would be expected. Sometimes this can occur from seizure activity arising from deeper areas of the brain but by the time it’s picked up on EEG, it’s just seen as slow waves and not as clear ‘epileptiform’ or seizure activity.
Can you have an abnormal EEG without having epilepsy?
To complicate this further, some people have ‘abnormal’ EEGs but do not have epilepsy. Also, many people who do have epilepsy will only have ‘abnormal’ activity on the EEG if they have a seizure at the time the test is happening.
Does an abnormal EEG mean epilepsy?
Medical issues to consider. An abnormal EEG doesn’t automatically mean that you, for example, have epilepsy. The EEGs of babies and young children can often record irregular patterns that don’t mean anything, or the irregularities may flag previously diagnosed neurological conditions such as cerebral palsy.
What is the meaning of photic stimulation?
pho·tic stim·u·la·tion. the use of a flickering light at various frequencies to influence the pattern of the occipital electroencephalogram and also to activate latent abnormalities.
Will EEG show previous seizure?
An EEG can usually show if you are having a seizure at the time of the test, but it can’t show what happens to your brain at any other time. So even though your test results might not show any unusual activity it does not rule out having epilepsy.
Can EEG detect anxiety?
EEG identifies brain signal that correlates with depression and anxiety.
What does a spike on an 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.
Can an EEG detect a previous seizure?
You may have had seizures in the past, such as brief absence seizures or auras, without knowing they were seizures. Doing an electroencephalogram (EEG), especially after sleep deprivation, may reveal abnormalities in the brain’s electrical activity that may help confirm the diagnosis of epilepsy.
What do sharp waves on an EEG mean?
What does generalized background slowing mean ON EEG?
Focal and Generalized Slowing and Significance. As previously discussed, generalized background slowing in the theta and delta frequency ranges is a normal finding on EEG when it represents developmental slowing in children, adolescents, and some young adults or the evolution of drowsiness and sleep activity.
How can eeeeg provide evidence of underlying cerebral dysfunction?
EEG can provide evidence for underlying diffuse or focal cerebral dysfunction through demonstration of background slowing. The two main types of slowing are focal and generalized slowing.
What does a normal EEG look like in dementia?
Early in the course of a slowly progressive neurodegenerative dementia, such as Alzheimer disease, the EEG may be normal during wakefulness and sleep. Later, as the disease progresses, there is frequently mild generalized background slowing. Focal slowing may also be seen.
What are the causes of abnormal EEG waveforms?
This is a very nonspecific EEG waveform abnormality that can be due to a wide variety of causes, most commonly as an effect of sedating medications, toxic metabolic derangements, or an underlying neurocognitive disorder. This is most often seen as polymorphic delta and/or theta activity which, in adults, is most often frontally predominant.