Why do sleep deprived eeg

In any case, the results are provocative, since limited compliance effectively produces a sleep-reduced, rather than a fully sleep-deprived, condition in many outpatients. Another alternative is prolonged, "ambulatory" EEG monitoring. The downside of full sleep deprivation involves substantial, unaccounted economic burdens, nonspecific disruption and stress, potential accidents, and occasional seizures. Patients kept awake through the night need to be accompanied to the test for safety.

Thus, for tests done on an ambulatory basis, not only the patient but at least one other person typically loses time at work or school. Despite the clear preponderance of positive evidence noted herein, summarized in the and reviews 1 , 7 and confirmed in key intervening studies, 8 , 9 authors who have made recommendations have not suggested routine, full sleep deprivation for the first EEG for suspected seizure; its inconvenience 10 outweighs the added value of the activation provided Nathan B.

Fountain, MD, written communication, August 2, Since those authors who offered advice did not specify the quantitative burden of that inconvenience or what marginal yield would justify sleep deprivation, their recommendations although they may represent the best current judgment lack a balanced evidence basis.

Thus, while the literature contains some conflicting results, a more striking disparity exists between the research evidence and the negative practice recommendations for the initial EEG by these experts and by those included in the survey. The present state of guidance is perhaps best conveyed by 4 recent, authoritative articles. If again normal, prolonged EEG and video monitoring should be performed. In contrast, the latest edition of Harrison's textbook of internal medicine recommends that EEGs for suspected seizures should "ideally" be performed after sleep deprivation.

Little evidence, informed opinion, or guidance on sleep-deprived EEGs has penetrated to practitioners. Variable research results and uncertainty as to the added benefit vs burdens appear to have clouded the atmosphere of education and practice.

Even lacking a sufficient evidence basis to issue a formal practice guideline, the expected cascade of reasoned information and advisories from professional societies, textbooks, and Web sites has not materialized. Many epileptologists derive their personal recommendations for the first EEG in cases of suspected seizure from their overall judgment of good management, rather than simplistically from the evidence for the added yield of sleep deprivation.

Those whom I contacted have modified their own practices, typically to omit full sleep deprivation for the initial EEG, but to reemphasize obtaining, if possible, a sleep tracing acknowledging the difficulties of consistently inducing sleep. Full sleep deprivation is reserved for repeated testing when clinically indicated. Improvement of diagnostic practice may best be served by comparative assessment of other approaches. Many of the experts whom I interviewed predicted that patients would increasingly be tested initially by prolonged "ambulatory" outpatient, awake and asleep EEG monitoring, with or without video, in place of sleep deprivation.

Quite possibly the preferred diagnostic approach will become increasingly individualized, at least in the hands of neurologists, to capitalize on factors relevant to each case. Additional research is needed to demonstrate, for the initial EEG for suspected seizure, a net diagnostic benefit and acceptable cost of extended monitoring and similarly for partial sleep deprivation.

In the meantime, epileptologists should seek consensus on what advice to offer regarding full sleep deprivation for the initial EEG.

If sleep deprivation were to be ordinarily reserved for a follow-up EEG, should an attempted sleep tracing as part of the initial EEG with or without previous sleep reduction be established as a practice standard and "officially" publicized to nonneurologists?

Instead, do technological advances, such as computer-assisted, ambulatory EEG and video monitoring, provide attractive alternatives that should be further researched and perhaps recommended for the first EEG?

The neurologic profession, led by epileptologists, should accept the ongoing opportunity and responsibility to inform and guide its members and nonneurologists on current evidence and best practices for EEG diagnosis of suspected seizures.

Corresponding author and reprints: Thomas H. Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy Continue.

View Large Download. J Clin Neurophysiol. Google Scholar. Electroencephalogr Clin Neurophysiol. Clin Neurophysiol. In: Degen R, Niedermeyer E, eds. Epilepsy, Sleep, and Sleep Deprivation. Amsterdam, the Netherlands: Elsevier Science Publishers; Together, these results in the alpha band suggest a shift toward a path-like topology for patients after sleep deprivation and a shift toward a star-like topology for controls. Previous research has shown that functional networks change during seizure generation and propagation into a more regular network organization i.

Furthermore, long-term continuous evaluation of functional networks derived from intracranial recordings, revealed large fluctuations in clustering coefficient and path length during the day Kuhnert et al.

These fluctuations over time, largely attributed to daily rhythms, showed an increased regularization of functional networks during night-time in patients with focal epilepsy Kuhnert et al. Possibly, this shift toward a more regular network during sleep in patients with epilepsy explains why the epileptic brain is more susceptible to both epileptiform discharges and seizures during sleep.

However, this remains speculative as we cannot infer a causal relation between network alteration and an increased presence of interepileptic discharges after sleep deprivation based on our results. We did not investigate network alterations during sleep, but a similar mechanism could explain the increased presence of epileptiform discharges after sleep deprivation.

This study suggests that the network organization shift toward a more path-like topology in patients with epilepsy i. Considering the path-like network as a network wherein nodes are less centrally connected and share basic characteristics with a regular network, it might be possible that the mechanisms underlying sleep deprivation-induced network alterations mimic the changes of a functional network during the ictal state or during sleep. Interestingly, these changes in network organization could coincide with an increase of cortical excitability that has previously been described as a pro-convulsive effect, accountable for the induction of epileptogenic activity after sleep deprivation Badawy et al.

As mentioned previously, functional connectivity in EEG networks is based on the assumption that an increased synchronization of frequency specific neurophysiologic activity implies an improved communication between brain areas. The change toward a more path-like network in patients with focal epilepsy after sleep deprivation suggests an increased synchronization of spatially closely related brain areas. The underlying mechanism behind the increased synchronization could indeed be an increased cortical excitability, as repeatedly shown by studies combining high-frequency transcranial magnetic stimulation and EEG connectivity measures in healthy controls, particularly in the alpha frequency band Fuggetta et al.

To which extent this relation is also accountable for epilepsy remains speculative until further investigations will simultaneously map cortical excitability and associated changes in function network organization. Furthermore, we found the largest group difference in the alpha frequency band.

Previous studies have suggested that each frequency band is associated with distinct networks and cognitive processes Von Stein and Sarnthein, ; Basar et al.

For example, spontaneous alpha activity is typically found when eyes are closed whereas task-related alpha activity is typically found during sensory, motor and primarily top-down cognitive processes Von Stein and Sarnthein, Although it remains uncertain how our results relate to changes in the cognitive domain, they suggest an involvement of the alpha frequency band in normal sleep physiology.

However, the exact relationship remains an open question. The MST approach has been suggested as an appropriate method to overcome certain limitations of network studies, particularly in relation to differences in network densities between groups Van Wijk et al. Nevertheless, few studies have compared standard network measures, such as clustering coefficient and path length, to MST measures Boersma et al.

We found particular network alteration between controls and patients for the MST measures leaf number and diameter, suggesting that these measures are perhaps more sensitive to network alterations in patients with epilepsy. Larger studies investigating and comparing both approaches are needed to verify this. In addition, like clustering coefficient and path length, leaf number and diameter are highly correlated, arguing for more and distinct MST features to characterize networks.

To date, only one study has investigated the influence of sleep deprivation on functional networks Koenis et al. Koenis and others reported network alterations in the alpha frequency band during an eyes-closed condition, namely a shift toward a more random network. In our control group, we found an increase in clustering coefficient, a decreased diameter and increased leaf number in the delta frequency band.

Together, these results suggest a more star-like MST network in controls after sleep deprivation. Interestingly, a star-like MST network shares basic characteristics with that of a random network organization i. Although we found a similar shift in network organization as Koenis and others, it is challenging to explain the differences in frequency bands between both studies alpha vs. Possibly, a different patient population age and methodology different EEG recordings are accountable for these differences Van Wijk et al.

Besides network measures, we also measured the relative power spectrum. In accordance with previous literature, we found an increase in beta power spectrum after sleep deprivation in healthy subjects Gast et al.

Possibly, the lack of increased beta power in patients after sleep deprivation reflects an inadequate compensation of the epileptic brain to maintain beta frequency band specific functions, such as integration of multi-sensory information Von Stein and Sarnthein, Although our study provides further insight in the mechanism of increased sensitivity of EEG recordings after sleep deprivation, several limitations should be mentioned.

First, our patient sample is limited 21 children and included only children with focal epilepsy. One could therefore argue that our results might be restricted to this age range and type of patients.

Nevertheless, the increased sensitivity of SD-EEG recordings is particularly manifested in children suspected of focal epilepsy Shinnar et al. Secondly, the control group contained children who were initially suspected of having suffered from an epileptic seizure.

Although epilepsy was excluded after clinical evaluation and follow-up, this could have introduced a bias in our results. As compared to truly healthy children who never experienced any paroxysmal event, the network organization of our control group could be altered as well. As a consequence this might have reduced our statistical group differences.

Otherwise, it would be difficult to receive ethical approval for performing SD-EEG recordings in a healthy pediatric population. Furthermore, since we used clinical EEG recordings, there was only a limited fraction of EEG recording available from which we could select resting state epochs.

Based on previous research, we assume that four epochs is enough to ensure stable network measures Douw et al. The availability of more epochs would allow further exploration on the variability—and thus stability—of these network measures by, for instance, performing a leave-one-out analysis.

Unfortunately, in this study we did not have sufficient data to do so, but we suggest future studies to characterize this variability using long-term EEG recordings. In three patients anti-epileptic drugs were started before the SD-EEG recording patients 1, 11, and Considering the potential influence of anti-epileptic drugs on functional networks Van Diessen et al.

In all three patients, however, treatment started only a few days before SD-EEG recording and was therefore still at a very low dosage. An additional analysis, after excluding these patients, revealed similar results. Finally, our sample size is small and the FDR-correction to minimize inflation of the type I error might not be perfect. Additional validation is therefore needed to confirm our findings.

Despite these limitations, we believe that our results legitimate a larger network study wherein the mechanism of increased sensitivity of EEG recordings after sleep deprivation will be investigated more thoroughly.

To enable a subanalysis of different epilepsy syndromes and allow correlation analysis between network measures and clinical characteristics such as age, gender and use of anti-epileptic drugs a larger study cohort is required. In conclusion, this study provides insights into the mechanisms behind the increased presence of epileptiform abnormalities after sleep deprivation in children with focal epilepsy. We suggest that an inadequate compensatory shift of the epileptic network toward a more path-like topology after sleep deprivation is accountable for the increased epileptiform abnormalities often found in patients with epilepsy.

Designed the experiments: Eric van Diessen, Willem M. Otte, Kees P. Braun, Cornelis J. Stam and Floor E. Performed the experiments: Eric van Diessen, Willem M. Wrote the graph analysis software: Cornelis J. Analyzed the data: Eric van Diessen, Willem M. Wrote the paper: Eric van Diessen, Willem M. Eric van Diessen, Willem M. Otte, and Kees P. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Badawy, R. Sleep deprivation increases cortical excitability in epilepsy: syndrome-specific effects. Neurology 67, — Epilepsy: ever-changing states of cortical excitability.

Neuroscience , 89— Basar, E. Gamma, alpha, delta, and theta oscillations govern cognitive processes. Bassett, D. Do not eat or drink anything containing caffeine between midnight and the time of your test. A sleep-deprived EEG takes about hours. This test is similar to a regular EEG, as described above, except without video.

You will complete your testing at home. Once your test is completed and equipment is returned, your neurologist will compare your brain waves to what is considered normal for your age. Actively scan device characteristics for identification.

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Develop and improve products. List of Partners vendors. 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.

Like standard EEGs, this non-invasive test is used to record the electrical activity of the brain and can pick up on abnormal brain waves through electrodes attached to the scalp. A standard EEG can detect seizures and diagnose epilepsy, but a sleep-deprived EEG may better detect more subtle seizures, like absence seizures or focal seizures. Learn about sleep-deprived EEGs, their purpose in diagnosing seizures, potential risks, and costs, and what to expect before, during, and after the testing is completed.

The relationship between sleep and epilepsy has been studied for years. The latter are abnormal electrical patterns that are characteristic of epilepsy and occur between clinical seizures.

A board-certified neurologist may recommend a sleep-deprived EEG after a person with suspected seizures has had a standard EEG test that failed to show any unusual electrical activity. Sleep deprivation can improve the accuracy of the diagnosis of epilepsy and increase the probability of detecting the characteristic electrical patterns known as epileptiform discharges.

Standard EEGs may detect many findings, including evidence of:. A sleep-deprived EEG further assesses changes in brain activity that can indicate various brain disorders, like epilepsy or other seizure disorders. A sleep-deprived EEG can be used to diagnose and differentiate various types of epilepsies. Sometimes seizure activity can manifest with psychiatric symptoms. Therefore, in some psychiatric presentations, a sleep-deprived EEG may be ordered by your healthcare provider to identify abnormalities that are typically seen with seizures.

The amount of sleep the person obtains the night before, the duration of the EEG, and the time of day the examination is administered are not specific to the test. These may contribute to some differences in the results at times encountered when comparing studies done at different institutions.

A sleep-deprived EEG is safe, painless, and poses no significant risk. Most people experience little or no discomfort during an EEG. Remember, the electrodes do not transmit electrical charges, they only pick up electrical activity from the brain itself. Like in alternative activation procedures involving photic stimulation fast, flashing lights or patterns or hyperventilation very quick breathing , sleep deprivation can trigger a seizure during the exam.

If you are undergoing a sleep-deprived EEG, you will be carefully monitored throughout the procedure. In case you have a seizure, which is a possibility among those who are predisposed to this condition and thus undergoing the testing, you would be treated with a fast-acting anti-seizure medication immediately. If the seizure is prolonged, as would occur in a condition called status epilepticus, oxygen and the appropriate safety equipment are kept nearby the monitoring room and a protocol would be followed to quickly end the disturbance.