PEDIATRICS Vol. 114 No. 5 November 2004, pp. 1337-1338 (doi:10.1542/peds.2004-0906)
COMMENTARY |
To Sleep or Not to Sleep: That Remains the Question
Department of Pediatrics, Connecticut Children's Medical Center, Hartford, CT 06106
Abbreviations: EEG, electroencephalogram
In this issue, Gilbert et al1 have provided some new insights into the utility of sleep deprivation before recording of electroencephalograms (EEGs), to increase the likelihood of identification of interictal epileptiform discharges. A design flaw, which makes the results less universally applicable, is that the subjects and referring physicians both represented heterogeneous groups. The subjects included children who were known epileptics, patients with initial seizures, children with and without antiepileptic drug treatment, and children with a variety of other presenting complaints. The referring physicians were specialists and generalists treating differing populations. Nevertheless, by comparing 2 time periods during which subjects underwent EEG recording with a standard sleep deprivation protocol or a non–sleep-deprivation protocol, the authors were able to establish a large enough sample size to provide some important results.
Of the 820 eligible subjects who underwent EEG recordings during the study periods, sleep occurred for 22% of those with a non–sleep-deprivation protocol, 44% of those with a partial sleep deprivation protocol, and 57% of those with a standard sleep deprivation protocol. This finding was statistically significant and suggested that a standard sleep deprivation approach is much more likely to result in stage II sleep during EEG recording. Whether recording EEGs with the addition of stage II sleep enhances diagnostic capability is a matter of conjecture. The authors noted that the identification of potentially epileptiform discharges was quite similar among children studied with a non–sleep-deprivation protocol and those studied with a partial sleep deprivation protocol or a standard sleep deprivation protocol. In fact, there were few differences in the identification of epileptiform activity among groups whether or not they had sleep recorded, independent of their sleep deprivation protocols. What was not clear from the study was whether the actual epileptiform discharges were identified within the sleep portion of the study or merely at some time during the recordings. Clearly, epileptiform discharges during sleep may be more pertinent for specific diagnostic questions, because they are related to behavioral phenomena that occur during sleep.
Whether sleep is spontaneous, pharmacologically induced, or subsequent to a sleep deprivation protocol, sleep has been considered traditionally to be an activator for interictal and ictal abnormalities. Similarly, arousal from sleep may induce ictal abnormalities that may be specifically diagnostic of some epileptic syndromes. The EEG appearance of hypsarrhythmia may occur only in sleep, and concomitant infantile spasms may be more evident during arousal from sleep.2,3 In the benign epilepsies of childhood with central temporal spikes (Rolandic epilepsy) or occipital spikes (Panayiotopoulos syndrome), spike discharges are much more frequent during drowsiness and sleep.3 This confirms the diagnosis in the proper clinical setting. Less frequently encountered epileptic syndromes are also identified with EEG recordings during sleep. These syndromes include Landau-Kleffner syndrome, autosomal dominant frontal lobe epilepsy, and some epileptic encephalopathies (eg, Ohtahara syndrome).3 An important point to be extracted from the current discussion is that a routine EEG is rarely diagnostic of epilepsy, whether or not sleep is obtained. A definitive diagnosis can be made only when specific epileptiform discharge patterns unique to a specific childhood epileptic syndrome or actual seizures are recorded. Nonepileptic phenomena (eg, benign sleep myoclonus) also can be positively identified during sleep.3,4 Interictal spike discharges, during wakefulness or sleep, can be useful in identifying potential markers of epilepsy, reflecting focal brain irritability or structural abnormalities or representing drug effects or an underlying encephalopathy. Gilbert et al1 were unable to provide insight regarding whether definitive diagnoses of epilepsy, specific epileptic syndromes, parasomnia, nonepileptic behavioral phenomena, or other clinically useful information were obtained with EEGs obtained during sleep, compared with EEGs without sleep.
Although the authors concluded that sleep deprivation should not be used routinely to increase the yield of pediatric EEGs, the yield is related to the identification of epileptiform discharges. The true utility of performing EEG studies with and without sleep is in more precisely addressing appropriately framed clinical questions. The diagnosis of epilepsy depends on a complete clinical assessment and not merely a test (EEG). EEGs can be valuable for diagnosis in a few specific circumstances, and recording during sleep can facilitate diagnosis when judiciously requested. From a practical standpoint, even partial sleep deprivation may be helpful.
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FOOTNOTES |
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Accepted May 6, 2004.
Address correspondence to Francis J. DiMario, Jr, MD, Department of Pediatrics, Connecticut Children's Medical Center, 282 Washington St, Suite 2A, Hartford, CT 06106. E-mail: fdimari{at}ccmckids.org
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REFERENCES |
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 TOP REFERENCES |
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- Gilbert DL, DeRoos S, Bare MA. Does sleep or sleep deprivation increase epileptiform discharges in pediatric electroencephalograms?
Pediatrics. 2004;114
:658
–662
[Abstract/Free Full Text] - Wong M, Trevathan E. Infantile spasms. Pediatr Neurol. 2001;24 :89 –98[CrossRef][Web of Science][Medline]
- Panayiotopoulos CP. A Clinical Guide to Epileptic Syndromes and Their Treatment. Chipping Norton, United Kingdom: Bladon Medical Publishing; 2002
- Caraballo R, Yepez I, Cersosimo R, Fejerman N. Benign neonatal sleep myoclonus. Rev Neurol. 1998;26 :540 –544[Medline]
PEDIATRICS (ISSN 1098-4275). ©2004 by the American Academy of Pediatrics
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