Yes, EEG can be bad for you. The consequences of being misdiagnosed with epilepsy are obvious and serious . When the diagnosis is based largely on an abnormal EEG, no amount of subsequent normal EEGs will 'cancel' the previous abnormal one, and the wrong diagnosis is very difficult to undo.
The consequences of misreading EEGs are many. First, it may delay arriving at the correct diagnosis. Once a patient is 'labeled' with a diagnosis, it is difficult to undo it. It requires obtaining the original EEG and reinterpreting it.
EEG review yielded 1-week accuracy in 10–52% of recordings, and 2-week accuracy in 28–75% of recordings (n = 146; Fig. 3E and F).
The EEG is abused
Over‐interpretation is an important cause of misdiagnosis of epilepsy. Developmental changes in the normal EEG, background EEG abnormalities, and “non‐epileptogenic epileptiform” abnormalities have all been used to erroneously support the diagnosis of epilepsy.
Abnormal results on an EEG test may be due to: Abnormal bleeding (hemorrhage) An abnormal structure in the brain (such as a brain tumor) Tissue death due to a blockage in blood flow (cerebral infarction)
Can anxiety cause abnormal EEG? Long-term anxiety and panic attacks can cause your brain to release stress hormones on a regular basis. This can increase the frequency of symptoms such as headaches, dizziness, and depression. All of which can alter the EEG.
This means that sometimes the EEG is described as 'abnormal' (that is 'not normal' brain activity) but does not 'prove' that the person has epilepsy. To complicate this further, some people have 'abnormal' EEGs but do not have epilepsy.
More than 10% of normal people may have non-specific EEG abnormalities and approximately 1% may have 'epileptiform paroxysmal activity' without seizures. The prevalence of these abnormalities is higher in children, with 2–4% having functional spike discharges.
Lights, especially bright or flashing ones. Certain medicines, such as sedatives. Drinks containing caffeine, such as coffee, cola, and tea (while these drinks can occasionally alter the EEG results, this almost never interferes significantly with the interpretation of the test) Oily hair or the presence of hair spray.
MRI has a higher spatial resolution than electroencephalography (EEG). MRI with hyperintense lesions on FLAIR and DWI provides information related to brain activity over a longer period of time than a standard EEG where only controversial patterns like lateralized periodic discharges (LPDs) may be recorded.
EEG identifies brain signal that correlates with depression and anxiety.
A normal EEG does not rule out the possibility of epilepsy. In fact, since the EEG records only a 30-minute snapshot of the brain's activity, many EEGs are normal. The sensitivity of the EEG—that is, the likelihood that the test will pick up abnormality—increases each time the test is run.
There is limited change in the EEG in the normal aging brain. After the age of 85 years, α rhythm frequency declines slightly to around 7-8 Hz. Isolated or intermittent temporal slow waves may be seen in up to one third of healthy subjects over the age of 65 years.
Electroencephalography (EEG) recordings after sleep deprivation increase the diagnostic yield in patients suspected of epilepsy if the routine EEG remains inconclusive. Sleep deprivation is associated with increased interictal EEG abnormalities in patients with epilepsy, but the exact mechanism is unknown.
An erroneous diagnosis of epilepsy is often the result of weak history and an "abnormal" EEG. Twenty-five to 30% of patients previously diagnosed with epilepsy who did not respond to initial antiepileptic drug treatment do not have epilepsy.
Abnormal EEG results can show up in two ways. First, normal brain activity may be suddenly interrupted and changed. This happens in epileptic seizures. In partial seizures, only part of the brain shows the sudden interruption.
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.
The low specificity and sensitivity of EEG (even in patients with clinical seizures as primary symptom of a brain tumor) underline that EEG does not contribute to diagnosis and a normal EEG might even delay correct diagnosis.
PNES are attacks that may look like epileptic seizures but are not epileptic and instead are cause by psychological factors. Sometimes a specific traumatic event can be identified. PNES are sometimes referred to as psychogenic events, psychological events, or nonepileptic seizures (NES).
EEG: If performed within 24-48 hours of a first seizure, EEG shows substantial abnormalities in about 70% of cases. The yield may be lower with longer delays after the seizure. If the standard EEG is negative, sleep-deprived EEG will detect epileptiform discharges in an additional 13-31% of cases.
Although dissociative seizures start as an emotional reaction, they cause a physical effect. Features of the seizure can include palpitations (being able to feel your heart beat), sweating, a dry mouth, and hyperventilation (over-breathing). Some features of dissociative seizures are very similar to epileptic seizures.
An electroencephalogram (EEG) is a noninvasive test that records electrical patterns in your brain. The test is used to help diagnose conditions such as seizures, epilepsy, head injuries, dizziness, headaches, brain tumors and sleeping problems. It can also be used to confirm brain death.
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.