The utility of routine EEG in the diagnosis of sleep disordered breathing.

Sleep disordered breathing (SDB) is a common medical condition. Its manifestations of snoring, nocturnal choking, arousals, and sleep fragmentation can lead to excessive daytime sleepiness, neuropsychological slowing, lapses of consciousness, and accidents that can be misinterpreted as epileptic phenomena. Moreover, patients with documented epilepsy commonly exhibit similar symptomatology because of the undiagnosed coexistence of sleep apnea. Therefore, a large proportion of patients referred to the electroencephalogram (EEG) laboratory primarily to confirm or refute the diagnosis of epilepsy could suffer from latent sleep apnea and the routine EEG has the potential to divulge it. We retrospectively evaluated the reporting of sleep apnea symptomatology (snoring, choking, gasping/deep breath, apnea, desaturation, excessive drowsiness) in routine inpatient and outpatient adult EEG studies performed in our institution over the past 12 years (39,130 studies, approximately half of which recorded at least early stages of sleep). Comparisons were performed with the medical records to ascertain the coexistence of objectively diagnosed SDB with polysomnography before or after the EEG study and the importance of reporting variations in assisting with the diagnosis. Two illustrative examples are provided. Sixty-nine EEG studies were identified, performed primarily to confirm, or refute the diagnosis of epilepsy. The mean age of the subjects at EEG was 64 years (range 30-89), and 55 (80%) were male. 36% of them suffered from known epilepsy. Snoring was the most commonly reported sign in 48 (70%) of the studies, followed by arousals in 29 (42%), apnea in 16 (23%), excessive drowsiness in 13 (19%), gasping/deep breath in 9 (13%), and desaturation in 7 (10%). A sleep disorder was suggested in 25 (36%) of the interpretations and a direct recommendation for a sleep study was made in 22 of them (32%). This interpretation was included in the impression of the report in 21 (30%) of the cases, in the detail in 20 (30%) of the cases and in both in 28 (40%). Only 14 (20%) patients underwent polysomnography, and all of them were formally diagnosed with SDB. Seven (50%) of them were diagnosed with obstructive sleep apnea, 2 (14%) with central sleep apnea, 3 (22%) with both, 1 (7%) with upper airways resistance syndrome, and 1 (7%) with primary snoring. From these 14 patients, 9 (64%) were diagnosed with a sleep study performed after the EEG, 4 (29%) before the EEG interpretation, and 1 (7%) had a repeat study after the EEG. In the logistic regression model applied, with the exception of the presence of arousals (odds ratio = 4.63, P = 0.033), none of the aforementioned symptomatology or the reporting of suspicion for SDB or the location (impression vs. detail) of the reporting showed a statistically significant association with the completion of a sleep study. Routine EEG offers a unique opportunity of direct clinical observation along with electrophysiologic and cardiorespiratory monitoring. When sleep is recorded, it can help identify clinical and electrographic features of sleep apnea and prompt confirmation with a polysomnogram in the appropriate clinical context. It can therefore serve as a valuable, adjunctive tool for the diagnosis of SDB. Our data highlight that potential but unveil its decreased use in the neurology community. Increased awareness is required by the EEG technologists, interpreting neurologists, and referring physicians, regarding reporting and using sleep apnea features on the EEG.

Decreased seizure activity in a human neonate treated with bumetanide, an inhibitor of the Na(+)-K(+)-2Cl(-) cotransporter NKCC1.

Neonatal seizures have devastating consequences for brain development and are inadequately treated by available antiepileptics. In neonates, gamma-aminobutyric acid (GABA) is an excitatory neurotransmitter due to elevated levels of intraneuronal chloride achieved by robust activity of the Na(+)-K(+)-2Cl( -) cotransporter (NKCC1). This depolarizing action of GABA likely contributes to the lowered seizure threshold, increased seizure propensity, and poor efficacy of GABAergic anticonvulsants among infants. The diuretic bumetanide inhibits NKCC1 and silences seizure activity in rodent models of neonatal seizures, but its effect on seizures in human neonates is unknown. Continuous electroencephalography (EEG) monitoring was used to quantify the number, duration, and frequency of seizures 2 hours before and after the administration of bumetanide in a neonate with intractable multifocal seizures. Significant reductions in mean seizure duration and frequency were noted following treatment, with no associated clinical side effects or metabolic imbalances. These results suggest bumetanide may exert antiepileptic effects in human neonates.

The effects of consecutive night shifts on neuropsychological performance of interns in the emergency department: a pilot study.

STUDY OBJECTIVE: We obtain preliminary information on the neuropsychological performance of house officers at the beginning and end of a shift while they worked consecutive night shifts in the emergency department. METHODS: We prospectively studied interns working 12-hour consecutive night shifts in an urban Level I trauma center ED. All consecutive non-emergency medicine interns rotating for 1 month were eligible except those older than 40 years and those with sleep disorders or depression (identified by using the Profile of Mood Scale, Sleep Diagnostic Questionnaire). We tested research subjects at the beginning of a day shift and at the beginning and end of night shifts 1 and 3 of 4 consecutive night shifts at times of estimated baseline wakefulness (10 PM) and maximum fatigue (3 AM). We used 3 standardized neuropsychological tests: (1) Delayed Recognition Span Test (visual memory capacity); (2) Continuous Performance Test (attentional function, vigilance); and (3) Santa Ana Form Board Test (psychomotor speed, coordination). We analyzed data with mixed-model analysis, with research subject as a random effect. RESULTS: Thirteen interns were eligible, and 1 declined. Twelve interns (6 men and 6 women; age range 25 to 35 years) were enrolled. The Delayed Recognition Span Test (number correct before first error) revealed significant deterioration from the beginning of the shift to the end of the shift (mean difference -2.2; 95% confidence interval -3.1 to -1.3). This represents an 18.5% decrease in visual memory capacity. There were no significant differences found for the other tests. CONCLUSION: Interns working nights demonstrated a significant reduction in visual memory capacity across the night shift. Research involving neuropsychological performance during night shifts in the ED is important. It might provide valuable insights into ways to improve our performance during night shifts.