Electroencephalogram (EEG) is a common medical test used to monitor and record the electrical activity of the brain. While EEG is generally considered safe, there are some potential side effects that patients should be aware of.
Berger continued to advance in his attempts to record EEGs as technology improved. His colleagues at the Institute of Brain Research in Berlin made significant improvements in the quality of the EEG with the help of JF Tonnies, who was an engineer at the institute. From the initial 1-channel EEG, Tonnies is credited with developing the first ink-writing oscillograph, which he called the neurograph. He went on to develop the first differential amplifier as well as the concepts of impedance and volume conduction (27).
Headaches
Minimum technical standards are similar for routine (24) and continuous EEG as well as for EEG use in a hospital or outpatient setting (33). However, advances in computer science and internet technology with faster broadband connections and networking have enabled remote access to EEG. In addition, advances in digital EEG have allowed the electroencephalographer to reformat the record post hoc for greater flexibility during interpretation. Phase reversal refers to the principle means of localization in bipolar recording. The phase reversal reflects the maximal amplitude electrophysiological phenomenon of interest (eg, spikes or sharp waves) where waveforms “point” towards each other in adjacent channels.
One of the most common side effects of using an EEG machine is experiencing headaches. This can be due to the tightness of the electrodes on the scalp or the flashing lights that are sometimes used during the test. Patients who are prone to migraines or headaches may find that their symptoms are triggered by an EEG.
After the test is complete, the technician will remove the electrodes from your scalp. Hyperventilation is also commonly induced during an EEG to produce abnormalities. Some people may not be able to hyperventilate safely, such as people with a history of stroke, asthma, or sickle cell anemia. Our patients tell us that the quality of their interactions, our attention to detail and the efficiency of their visits mean health care like they’ve never experienced. A review of the “abnormal” EEG and an interpretation of the follow-up interictal EEG was performed. Interictal refers to the period between seizures, or convulsions characteristic of an epilepsy disorder.
Discomfort
EEG graphically displays voltage differences between two sites of the brain to represent intrinsic function recorded over time. Because surface electrodes are routinely used to record EEG, the scalp, skull, and meninges serve as barriers to influence the EEG; therefore, features of the cortical waveforms may be altered. To ensure the accuracy of the recording where very low amplitude electrophysiological potentials are encountered, the technical aspects of recording are important to understand and maintain.
If the healthcare provider performing the test does not review your results with you immediately, the provider will send the results to the ordering provider. In that situation, you may need to schedule a follow-up appointment with the ordering healthcare provider to review EMG test results. You can generally return to normal activities a few hours after the procedure. Resuming activities depends on when memory loss and confusion are resolved.
This is opposed to “in-phase” electrodes that commonly signal the brain as the generator. In addition, the frequency of a “spike” that is shorter than 15 msec is unlikely to be generated by the brain and instead more likely to be derived from a muscular source. When sustained, this may be recognized as a normal feature of the EEG known as the photomyogenic response. There are similarities between recording techniques, strategies of recordings, and interpretations of EEG features performed for both pediatric patients and adults.
Some patients may experience discomfort during an EEG test. This can be caused by the adhesive used to attach the electrodes to the scalp, as well as the need to sit still for an extended period of time. Patients who have sensitive skin may also develop redness or irritation from the adhesive.
Anxiety
Another side effect of an EEG machine is anxiety. Some patients may feel anxious or claustrophobic while undergoing the test, especially if they are required to lie still in a confined space for an extended period of time. It is important for healthcare providers to reassure patients and provide support during the test to help alleviate anxiety.
Seizures
In rare cases, an EEG machine may trigger a seizure in patients with epilepsy or a history of seizures. This is more likely to occur during a prolonged EEG test where the patient is sleep-deprived or exposed to flashing lights. Healthcare providers should be prepared to manage any seizure activity that occurs during an EEG test.
In conclusion, while EEG is generally safe, there are some potential side effects that patients should be aware of. These include headaches, discomfort, anxiety, and in rare cases, seizures. It is important for healthcare providers to discuss these potential side effects with patients before performing an EEG test and to provide support and reassurance throughout the procedure.
