Epilepsy and epileptiform activity in late-onset Alzheimer disease: clinical and pathophysiological advances, gaps and conundrums

A growing body of evidence has demonstrated a link between Alzheimer disease (AD) and epilepsy. Late-onset epilepsy and epileptiform activity can precede cognitive deterioration in AD by years, and its presence has been shown to predict a faster disease course. In animal models of AD, amyloid and tau pathology are linked to cortical network hyperexcitability that precedes the first signs of memory decline. Thus, detection of epileptiform activity in AD has substantial clinical importance as a potential novel modifiable risk factor for dementia. In this Review, we summarize the epidemiological evidence for the complex bidirectional relationship between AD and epilepsy, examine the effect of epileptiform activity and seizures on cognition in people with AD, and discuss the precision medicine treatment strategies based on the latest research in human and animal models. Finally, we outline some of the unresolved questions of the field that should be addressed by rigorous research, including whether particular clinicopathological subtypes of AD have a stronger association with epilepsy, and the sequence of events between epileptiform activity and amyloid and tau pathology.

0820 Sleep and Oculopharyngeal Muscular Dystrophy: disease progression affecting ventilatory needs and treatment of sleep-disordered breathing

Introduction

Oculopharyngeal muscular dystrophy (OPMD) is an autosomal-dominant, late-onset, and progressive disease characterized by ptosis and dysphagia, sometimes proximal limb weakness and gait abnormalities. It often presents in patients in their 50s. The progressive functional decline of the pharyngeal muscles results in feeding difficulties and aspiration; however, patients may also have risk of nocturnal hypoventilation and sleep apnea, complicated by variable airway obstruction and compliance.

Report of Cases: Using retrospective chart review, we identified patients with a known diagnosis of OPMD treated at the Raymond G. Murphy VA Sleep Center. We present a case where OPMD progression necessitated increased ventilatory support and affected positive airway pressure (PAP) compliance. A 58-year-old male with OPMD, DMT2, depression, and memory impairment underwent home sleep apnea testing showing severe OSA (REI 32.7, SpO2 nadir 72%). He started Auto-PAP 6-16 cwp and presented to discuss issues tolerating PAP. Pressures were lowered, but he continued to require maximum pressures without increased utilization. An in-lab CPAP titration showed treatment-emergent centrals but did not find optimal pressures due to limited sleep time. Having failed CPAP, he returned for an ASV titration which controlled his apnea in lateral position. Patient was switched to auto ASV to increase efficacy and comfort. Two months later he discontinued ASV due to frustration with disease progression and feeling unable to breathe deeply with the machine. Nocturnal oxygen at 1L was ordered while he awaited Neurology consult for OPMD. Later, concerned about progressive dyspnea, he resumed ASV, now with 3L O2 bleed. Given suspicion of hypoventilation (bicarbs 27-30), and that ASV could not adjust to his continually changing airway tone with his OPMD, he was switched to iVAPS. This resulted in good control of his sleep apnea, tidal volumes and minute ventilation. However, he reported pressures felt too high, returned to ASV for a period, then discontinued PAP altogether.

Conclusion

Patients with OPMD and sleep apnea require close follow-up as their disease progression may affect their ventilatory support needs. These patients may require more complex PAP modalities, such as AVAPs, and routine PFTs to help determine timing of ENT involvement for surgical airway planning.

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0709 The Efficacy of Home Sleep Apnea Tests Alone in Determining Optimal Treatment Modality for Sleep Disordered Breathing During the Height of the COVID-19 Pandemic

Introduction

Home sleep studies have shown strong accuracy and reliability in diagnosing obstructive sleep apnea compared to PSG. Recent studies have suggested they can accurately detect central sleep apnea as well. The combination of better technology, stricter insurance requirements for in lab polysomnograms, and a rise in telemedicine has seen their utilization rapidly increase. Specifically, at the height of the COVID pandemic many sleep practices had to shut down their labs and rely on HSATs alone to evaluate patients with potential sleep disordered breathing.

Methods

The Albuquerque VA Sleep Center was one of these, which provided an opportunity to reflect on the effectiveness of this diagnostic modality over that timeframe. A total of 780 patients with suspected sleep disordered breathing were studied using ResMed ApneaLink II Machines from 3/16/21 to 7/1/21 while in lab PSGs were unable to be completed due to health and safety guidelines.

Results

Of these 780 patients, only 34 were determined to need further evaluation with an in lab titration study once the lab reopened. Given how few of these patients ended up with titration studies, no additional criteria were used to categorize them other than a provider deciding they needed the study. The charts of these patients were reviewed in detail to identify any common characteristics that could have contributed to them needing a more detailed evaluation with an in lab polysomnogram. This provided further information about the accuracy and reliability of HSATs, as well as traits of patients who would have been ideally studied with an in lab PSG instead.

Conclusion

Overall such a small percentage of patients, only 4%, needing further titration speaks to both the reliability of HSATs as diagnostic studies, and the effectiveness of remote titration through cloud based monitoring systems like AirView.

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797 Obstructive Sleep Apnea is a Risk Factor for Sudden Unexplained Death in Epilepsy (SUDEP)

Introduction

Epilepsy is associated with a substantial risk of morbidity and mortality, including sudden unexplained death in epilepsy (SUDEP). Prior data demonstrated a possible association between obstructive sleep apnea (OSA) based on nocturnal oximetry oxyhemoglobin saturation index (ODI) and risk of SUDEP. We aimed to evaluate the relationship between PSG-defined OSA and SUDEP risk using the revised SUDEP Risk Inventory (rSUDEP-7).

Methods

We identified adults with epilepsy who underwent PSG between January 2004 and December 2016 at Cleveland Clinic. OSA was defined as an apnea-hypopnea index (AHI) ≥5 and moderate-to-severe OSA as an AHI ≥ 15. SUDEP risk was determined by the rSUDEP-7. The higher the rSUDEP-7 score, the greater the risk for SUDEP. Associations between rSUDEP-7 score and OSA groups (AHI>15 vs. <15) used Wilcoxon rank sum tests, and multivariable linear models adjusting for age, sex, BMI, and smoking status. Spearman correlations measured relationships between rSUDEP-7 score with AHI and ODI.

Results

214 patients were identified; 134 (62.6%) had OSA, moderate-to-severe in 75 (35%). Those with AHI≥15 were older and more likely to have: pharmacoresistant epilepsy, nocturnal seizures, higher BMI, and longer epilepsy duration (all p<0.05). Median rSUDEP-7 score was 1(0,3), and > 35% had rSUDEP-7 score of > 3. Patients with moderate-to-severe OSA had higher rSUDEP-7 than those with AHI<15 (p=0.001). Higher AHI and ODI positively correlated with rSUDEP-7 (p=0.002 and p=0.016) while SpO2 nadir negatively correlated with rSUDEP-7 (p=0.007). After adjustment, those with AHI≥15 had mean rSUDEP-7 score 1.14 points (95%CI 0.55–1.72, p<0.001) higher than those with AHI<15.

Conclusion

Epilepsy patients with moderate-to-severe OSA, have higher risk of SUDEP based on the rSUDEP-7. Our findings provide further support for routine screening of OSA in epilepsy populations.

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802 Seizure-Associated Central Respiratory Events: What’s Sleep Go To Do With It?

Introduction

Seizure-related respiratory dysfunction has been reported in patients with epilepsy(PWE) on scalp EEG. We assessed this in Stereo-EEG(SEEG) recordings in patients with pharmacoresistant focal epilepsy.

Methods

PWE undergoing SEEG wore temperature/pressure-based airflow,RIP belts, SpO2, and EtCO2/TcpCO2. Interpretable recordings required SpO2 and at least one airflow and effort channel. Respiratory events including apneas, hypopneas(3%) and central pauses (5 to<10sec). Respiratory events, respiratory rate(RR), SpO2 nadir, total desaturation time, Peak EtCO2/TcpCO2, and hypercapnia duration were analyzed surrounding seizures. Frequency and duration of central events were compared in sleep-onset and awake seizures. Linear mixed-effects models evaluated relationships between respiratory variables and the frequency and duration of central events associated with seizures and compared respiratory variables between seizures with and without events.

Results

44 seizures were recorded in 23 patients. Seizures were focal-onset in 79.5%(n=35), GTC in 20.5%(9). Respiratory events accompanied 61.4%(27) of the seizures with median duration/seizure duration of 0.40(IQR: 0.27, 0.61). Of the 47 respiratory events, 42 were central events, and 66.6%(28) were central apneas. Respiratory events occurred during the seizure in 73.8%, postictal in 26.2%; median SpO2 nadir was 90%(77.0, 93.0), total desaturation duration 104.3(50.3, 195.0)sec, peak TcpCO2 41.3(38.7, 44.8) mmHg, hypercapnia duration 157.6(51.0, 367.9) sec, and ictal-postictal RR change 3.3 ± 4.0bpm. For every 1 sec duration increase in central event duration, there was a significant increase in peak TcpCO2 0.35(95%CI [0.09,0.62],p=0.015) and TcpCO2 change 0.25(95%CI [0.02,0.49],p=0.037). Presence of central events were associated with increased peak TcpCO2(9.82[3.77,15.9], p=0.006). Seizures with central events trended greater changes in RR, SpO2, and EtCO2/TcpCO2, desaturation and hypercapnia time, with negative changes in SpO2 nadir. No significant difference on central event frequency was found between sleep-onset and awake seizures.

Conclusion

Central events including apneas and pauses are common in focal seizures arising from sleep and wake and are associated with hypercapnia. In addition to the significant association between TcpCO2 and the frequency and duration of central events, there is a positive trend of association of other respiratory dysfunction parameters. These findings suggest that central events may lead to a cascade of respiratory disturbance that may participate in the pathophysiology of sudden unexplained death in epilepsy.

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862 Volume-Assured Pressure Support improves outcomes in a patient with Congenital Central Hypoventilation Syndrome

Introduction

Congenital Central Hypoventilation Syndrome (CCHS) is a condition caused by a mutation of the PHOX2B gene and an incidence of 1 in 50,000 live births. Clinically the condition is characterized by autonomic nervous system dysfunction, the most prominent feature of which is the failure of respiratory homeostasis during sleep. In patients severely affected, life-long ventilatory support is required. This might start as early as the newborn period. Subsequent adjustments are required due to their growth and development. The role of Volume-Assured Pressure Support (VAPS) ventilation in treatment of CCHS was only described in a couple reports before.

Report of case(s)

A 17-year-old female patient born at term and diagnosed with CCHS at birth at our center with a PHOX2B mutation confirmed. Her daytime ventilatory support was weaned at age 18 months and the tracheostomy was removed at age 10 years old. She relocated to another state, was lost to follow-up, and returned this year for adjustments of her ventilator whose settings had not been adjusted for several years. She was on a Trilogy 100 ventilator, in pressure-controlled mode with settings of EPAP 5, IPAP 20, and a rate of 22/min without supplemental oxygen. Her measured weight is 69kg, body mass index (BMI) 27. The patient complained of difficulty breathing while on those settings and reported decreased desire to use the machine. The patient was empirically switched to VAPS due to titration availability limitations during the COVID-19 pandemic. Initial AVAPS settings were: EPAP 4–7, PS 3–12, breath rate 16/min, TV 350mL. Upon implementing the changes, the patient reported improved comfort and increased usage. Average minute ventilation decreased from 10.5 to 5.8 L/min, patient triggered breaths increased from 1.1% to 12.3%, average breaths per minute decreased from 22.0/min to 16.2/min, the average peak flow 31.8 to 26.2L/min, tidal volume decreased from 463 to 355mL.

Conclusion

AVAPS ventilation can be successfully used in managing patients with CCHS, and it might be superior to pressure-controlled mode in certain cases, improving patient comfort and compliance.

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Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM.

718 Investigating Decreased Positive Airway Pressure Compliance in a Veteran Affairs Sleep Medicine Clinic During the 2020 Pandemic

Introduction

Positive airway pressure (PAP) compliance for the treatment of sleep apnea at the Albuquerque Veterans Affairs (VA) Sleep Medicine clinic has been observed to be lower in new setup patients after the onset of the COVID-19 pandemic. The reasons for decreased PAP compliance during the COVID-19 pandemic are unclear. The primary outcome will be to identify if there is a common reason that patients at the Albuquerque VA were less compliant with PAP after the onset of the COVID-19 pandemic.

Methods

Compliance data for 4/1/2020 through 9/30/2020 was compared to compliance data for 4/1/2019 through 9/30/2019. Compliance after PAP machine setup was confirmed to be lower during the 2020 time period. Noncompliant patients will be selected by setup type, new versus machine replacement, and surveyed for reasons for noncompliance. The survey will be conducted at the Albuquerque VA Sleep Center and will include questions regarding beliefs, barriers, and challenges with the use of PAP therapy during the coronavirus pandemic. The definition for initial PAP compliance will be the use of PAP therapy for greater than or equal to four hours per night on at least 70% of nights.

Results

For the 6-month time period of 4/1/2019 through 9/30/2019, there were 758 PAP setups at the Albuquerque VA. The 30-day compliance for the 758 setups was found to be 61.4%. Comparatively, for the six-month period of 4/1/2020 through 9/30/2020, there were 462 setups with a 30-day compliance result of 49.7%. A survey consisting of questions designed to elicit barriers to use as well as beliefs regarding PAP and COVID-19 will be administered to 20% (n = 46) of the non-compliant patients who were set up with a PAP machine during the 2020 study period.

Conclusion

PAP compliance after machine setup was lower at the Albuquerque VA sleep center in 2020 versus 2019 (49.7% versus 61.4%). The reasons for the lower observed compliance are attributed to the effects of the coronavirus pandemic. A random sampling of the non-compliant patients during the 2020 time period will be performed and the results will be presented once available.

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None

795 Real World Challenges and Barriers for Positive Airway Pressure Therapy Use in Acute Ischemic Stroke Patients

Introduction

Untreated obstructive sleep apnea (OSA) in patients with acute ischemic stroke (AIS) increases morbidity and mortality post-stroke. However, diagnosing and treating OSA in AIS is challenging. As such, we aimed to determine the feasibility of portable monitoring (PM) for diagnosis and positive airway pressure (PAP) therapy for treatment of OSA in an inpatient stroke population.

Methods

We recruited inpatients with AIS from the Cleveland Clinic. Those who consented underwent PM; participants with a respiratory event (REI) ≥10 were offered auto-titrating positive airway pressure therapy (APAP). Ease-of-use questionnaires were completed. We summarized categorical variables using n(%) and continuous variables using mean±SD or median [IQR].

Results

27 participants (age 59.8±11.8, 51.9% female, 51.9% African American, BMI 33.3±11.4) enrolled. The study ended early due to Medicare contracting that forced most patients to complete stroke rehabilitation outside the Cleveland Clinic health system. 69.6% had large vessel occlusions and 52% had moderate/severity disability (Modified Rankin score ≥2). PM was attempted in 23 participants and successful in 19. Nursing and patients rated the PM device as highly easy to use. 11 of 14 patients who had an REI ≥10 consented to APAP titration, but only 5 continued APAP after discharge. Four patients who initially said APAP was easy to use noted that their stroke interfered with their APAP use at home.

Conclusion

This study demonstrates the challenges in the assessment and treatment of OSA in an acute ischemic stroke population, highlighting the necessity for further research into timely and feasible screening and treatment.

Support (if any)

ResMed

Bidirectional relationships of sleep and epilepsy in adults with epilepsy

This targeted review addresses the best accepted and most intriguing recent observations on the complex relationships between sleep and epilepsy. Ten to 15% of all epilepsies are sleep-related. Included in these is sleep-related hypermotor epilepsy, renamed from nocturnal frontal lobe epilepsy by a 2016 consensus conference since 30% of cases are extra-frontal, seizures are related to sleep rather than clock time, and the predominant semiology is hypermotor. Stereo-EEG is providing crucial insights into network activation in sleep-related epilepsies and definition of the epileptogenic zone. Pathologic high-frequency oscillations, a promising biomarker for identifying the epileptogenic zone, are most frequent in NREM sleep, lowest in wakefulness and REM sleep, similar to interictal epileptiform discharges (IEDs). Most sleep-related seizures are followed by awakening or arousal and IEDs cause arousals and increase after arousals, likely contributing to sleep/wake complaints. Sleep/wake disorders are 2-3 times more common in adults with epilepsy than the general population; these comorbidities are associated with poorer quality of life and may impact seizure control. Treatment of sleep apnea reduces seizures in many cases. An emerging area of research is in circadian biology and epilepsy. Over 90% of people with epilepsy have seizures with circadian periodicity, in part related to sleep itself, and the majority of SUDEP cases occur in sleep. Recognizing these bidirectional relationships is important for patient and caregiver education and counseling and optimizing epilepsy outcomes.

Subjective and objective hypersomnia highly prevalent in adults with epilepsy

INTRODUCTION

Sleepiness is among the most common complaints of people with epilepsy, but objective documentation is lacking. We systematically investigated subjective and objective sleepiness in an observational cross-sectional cohort of adults with epilepsy (AWE).

METHODS

This is a prospective study of AWE consecutively recruited without foreknowledge of sleep/wake complaints. Polysomnography (PSG) with 18-channel electroencephalography (EEG) followed by multiple sleep latency testing (MSLT) was performed. Patients completed the Epworth Sleepiness Scale (ESS), a single-item question assessing excessive daytime sleepiness (EDS), and a 7-day sleep and seizure diary. Multivariable linear models were used to assess the association between MSLT mean sleep latency (MSL) and interests with adjustment of covariates of interest. Receiver operating characteristics (ROC) analysis was performed to evaluate the discrimination capability of ESS on MSL < 8 min and <5 min and investigate the optimal cutpoints.

RESULTS

Among 127 AWE (mean age: 38.7 ± 13.7 years), abnormal MSL (<8 min) was observed in 49.6% and MSL <5 min in 31.5%. While 78% reported feeling sleepy during the day on a single-item question, only 24% had elevated scores on the ESS (>10/24). The ESS score was associated with MSL even after adjusting for seizure frequency, antiseizure medication (ASM) standardized dose and number, age, gender, depression and insomnia symptom severity, and apnea-hypopnea index (HPI) and total sleep time on PSG (coefficients [95% confidence interval (CI)]: -0.26 [-0.48, -0.05], p = 0.018). The area under the curve (AUC) of the ESS ROC predicting MSL < 8 min and MSL < 5 min were similar: 0.62 (95%CI: 0.52-0.72) and 0.62 (95%CI: 0.51-0.74).

CONCLUSIONS

This is the largest prospective cross-sectional observational study to date using MSLT in AWE. We found subjective and objective daytime sleepiness highly prevalent in AWE and not explained by seizure frequency, ASM burden, symptoms of insomnia/depression, or PSG findings although those with MSL < 5 min were more likely to have obstructive sleep apnea (OSA). Pathologic sleepiness with MSL < 8 min was present in half of AWE. Nearly one-third of AWE unselected for sleep/wake complaints had MSL < 5 min, a range typical of narcolepsy.

Eyes wide open minds shut best identify disorders of arousal in adult sleepwalkers

Grigg-Damberger M, Foldvary-Schaefer N. Eyes wide open minds shut best identify disorders of arousal in adult sleepwalkers. J Clin Sleep Med. 2020;16(1):7–8.

Wake up to sleep: The effects of lacosamide on daytime sleepiness in adults with epilepsy

OBJECTIVE

The objective of the study was to investigate the effects of lacosamide (LCM) on daytime sleepiness ascertained by the Epworth Sleepiness Scale (ESS) in adults with focal epilepsy in a randomized, controlled design.

METHODS

Subjects taking ≤2 AEDs for ≥4weeks underwent polysomnography with EEG followed by the maintenance of wakefulness test (MWT) and completed the ESS and other patient-reported outcomes (PROs) at baseline, LCM 200mg/day, and LCM 400mg/day (Visit 4; V4). Primary endpoint was ESS change (V4 to baseline) between LCM and placebo. Noninferiority test on ESS used a one-sided t-test based on a hypothesized difference of 4-point change between groups. Superiority test used a two-sided t-test to investigate the difference in change in PROs and MWT mean sleep latency (MSL) between groups. Fifty-five subjects provided 80% power to show noninferiority of LCM assuming 10% dropout.

RESULTS

Fifty-two subjects (mean age: 43.5±13.2years, 69% female, median monthly seizure frequency: 1 [0, 4.0]) participated. Baseline group characteristics including age, sex, ethnicity, standardized AED dose, seizure frequency, and ESS were similar. Abnormal baseline ESS scores were found in 35% of subjects. Noninferiority test found a ≤4-point increase in ESS (mean [95% CI]) in LCM subjects vs. placebo (-1.2 [-2.9, 0.53] vs. -1.1 [-5.2, 3.0], p=0.027) at V4. No significant difference in change in PROs, MSL, seizure frequency, or AED standardized dose was observed between groups.

SIGNIFICANCE

Our interventional trial found that LCM is not a major contributor to daytime sleepiness based on subjective and objective measures. Inclusion of sleepiness measures in AED trials is warranted given the high prevalence of sleep-wake complaints in people with epilepsy.

Severity of self-reported insomnia in adults with epilepsy is related to comorbid medical disorders and depressive symptoms

BACKGROUND

Few studies have systematically investigated insomnia in adults with epilepsy.

METHODS

We performed a prospective cross-sectional investigation of the prevalence, severity, and comorbidities of insomnia in 90 adults with epilepsy using a battery of self-reported instruments and polysomnography. We quantified insomnia severity using the Insomnia Severity Index (ISI).

RESULTS

Fifty-nine of 90 (65.5%) adults with epilepsy reported insomnia (ISI≥8), moderate or severe (ISI≥15) in 28.9%. Good agreement between standard clinical diagnostic criteria and ISI was found for patients with ISI scores <8 and ≥15. Scores on the modified Beck Depression Inventory (mBDI) (r=0.25, p=0.021), the original BDI (r=0.32, p=0.002), and self-reported total sleep duration (TSD) (r=-0.3, p=0.006) were significantly related to ISI score. A multiple regression model found that decreased TSD (ß=-0.93, p=0.007), head trauma (ß=4.37, p=0.003), sedative-hypnotic use (ß=4.86, p=0.002), AED polytherapy (ß=3.52, p=0.005), and asthma/COPD (ß=3.75, p=0.014) were predictors of a higher ISI score. For 63 patients with focal epilepsy, an increased mBDI (ß=0.24, p=0.015), decreased TSD (ß=-1.11, p=0.008), asthma/COPD (ß=4.19, p=0.02), and epilepsy surgery (ß=5.33, p=0.006) were significant predictors of an increased ISI score. Patients with temporal lobe epilepsy (TLE) showed a trend for greater severity compared with those with extra-TLE (ß=-2.92, p=0.054).

CONCLUSIONS

Our findings indicate that severity of insomnia in adults with epilepsy is more likely to be associated with comorbid medical and depressive symptoms and less likely to be directly related to epilepsy. Good agreement between standard clinical diagnostic criteria for insomnia and the ISI for subjects without insomnia symptoms and for those with moderate-to-severe symptoms supports the use of this instrument in epilepsy research.

Sleep and epilepsy

Over a century of work has confirmed crucial links between sleep and epilepsy. Seizures and some antiepileptic drugs (AEDs) adversely affect the continuity of sleep. However, sleep is fragmented in the absence of seizures or medication, suggesting that sleep instability may be an inherent component of certain forms of epilepsy. In turn, sleep instability can promote seizures, thus forming a vicious cycle. Sleep deprivation provokes seizures and epileptiform discharges in some people with epilepsy. Synchronized nonrapid eye movement (NREM) sleep facilitates seizures, whereas desynchronized rapid eye movement (REM) sleep discourages seizure occurrence. The sleep electroencephalogram (EEG) is useful in the diagnosis and localization of epilepsy, as new epileptic foci can appear in sleep and REM sleep may demonstrate the narrowest localization of the primary focus. Polysomnography (PSG) with expanded EEG aids in the differentiation of seizures and parasomnias and in the diagnosis of primary sleep disorders, such as sleep apnea, that can exacerbate seizures. Treating sleep apnea may lead to improved seizure control. These observations underscore the importance of sleep in the diagnosis and treatment of people with epilepsy.

Development and results of the first ABMS subspecialty Certification Examination in Sleep Medicine

In November 2007, the first Certification Examination in Sleep Medicine was administered to 1,882 candidates under the cosponsorship of five member boards of the American Board of Medical Specialties (ABMS)--the American Board of Internal Medicine, the American Board of Family Medicine, the American Board of Otolaryngology, the American Board of Pediatrics, and the American Board of Psychiatry and Neurology. The pass rate was 73%. This paper chronicles the history of a certification examination in Sleep Medicine and the development of this new ABMS examination.

The visual scoring of sleep and arousal in infants and children

Age is probably the single most crucial factor determining how humans sleep. Age and level of vigilance significantly influence the electroencephalogram (EEG) and the polysomnogram (PSG). The Pediatric Task Force provide an evidence-based review of the age-related development of the polysomnographic features of sleep in neonates, infants, and children, assessing the reliability and validity of these features, and assessing alternative methods of measurement. We used this annotated supporting text to develop rules for scoring sleep and arousals in infants and children. A pediatric EEG or PSG can only be determined to be normal by assessing whether the EEG patterns are appropriate for maturational age. Sleep in infants at term can be scored as NREM and REM sleep because all the polysomnographic and EEG features of REM sleep are present and quiet sleep, if not NREM sleep, is at least "not REM sleep." The dominant posterior rhythm (DPR) of relaxed wakefulness increases in frequency with age: (1) 3.5-4.5 Hz in 75% of normal infants by 3-4 months post-term; (2) 5-6 Hz in most infants 5-6 months post-term; 3) 6 Hz in 70% of normal children by 2 months of age; and 3) 8 Hz (range 7.5-9.5 Hz) in 82% of normal children age 3 years, 9 Hz in 65% of 9-year-olds, and 10 Hz in 65% of 15-year-old controls. Sleep spindles in children occur independently at two different frequencies and two different scalp locations: 11.0-12.75 Hz over the frontal and 13.0-14.75 Hz over the centroparietal electrodes; these findings are most prominent in children younger than 13 years. Centroparietal spikes are often maximal over the vertex (Cz), less often maximal over the left central (C3) or right central (C4) EEG derivation. About 50% of sleep spindles within a particular infant's PSG are asynchronous before 6 months of age, 30% at 1 year. Based on this, we recommend that: (1) sleep spindles be scored as a polysomnographic signature of NREM stage 2 sleep (N2) at whatever age they are first seen in a PSG, typically present by 2 to 3 months post-term; (2) identify and score sleep spindles from the frontal and centroparietal EEG derivations, especially in infants and children younger than 13 years. NREM sleep in an infant or child can be scored if the dominant posterior rhythm occupies <50% of a 30-second epoch, and one or more of the following EEG patterns appear: (1) a diffuse lower voltage mixed frequency activity; (2) hypnagogic hypersynchrony; (3) rhythmic anterior theta of drowsiness; (4) diffuse high voltage occipital delta slowing; (5) runs or bursts of diffuse, frontal, frontocentral, or occipital maximal rhythmic 3-5 Hz slowing; (6) vertex sharp waves; and/or (7) post-arousal hypersynchrony. K complexes first appear 5 months post-term and are usually present by 6 months post-term, whereas clearly recognizable vertex sharp waves are most often seen 16 months post-term. Vertex sharp waves are best seen over the central (Cz, C3, C4) and K complexes over the frontal (Fz, F3, F4) electrodes. Slow wave activity (SWA) of slow wave sleep (SWS) is first seen as early as 2 to 3 months post-term and is usually present 4 to 4.5 months post-term. SWA of SWS in an infant or child often has a peak-to-peak amplitude of 100 to 400 microV. Based on consensus voting we recommended scoring N1, N2, and N3 corresponding to NREM 1, 2, and SWS whenever it was recognizable in an infant's PSG, usually by 4 to 4.5 months post-term (as early as 2-3 months post-term). Epochs of NREM sleep which contain no sleep spindles, K complexes, or SWA would be scored as N1; those which contain either K complexes or sleep spindles and <20% SWS as N2, and those in which >20% of the 30-second epoch contain 0.5 to 2 Hz >75 microV (usually 100-400 microV) activity as N3. The DPR should be scored in the EEG channel that is best observed, (typically occipital), but DPR reactive to eye opening can be seen in central electrodes. Because sleep spindles occur independently over the frontal and central regions in children, they should be scored whether they occur in the frontal or central regions. Because sleep spindles are asynchronous before age 2 years, simultaneous recording of left and right frontal and central activity may be warranted in children 1-2 years of age. Simultaneous recording of left, right, and midline central electrodes may be appropriate because of the asynchronous nature of sleep spindles before age 2 years, but reliability testing is needed. Evidence has shown that the PSG cannot reliably be used to identify neurological deficits or to predict behavior or outcome in infants because of significant diversity of results, even in normal infants. Normal sleep EEG patterns and architecture are present in the first year of life, even in infants with severe neurological compromise. Increasing evidence suggests that sleep and its disorders play critical roles in the development of healthy children and healthy adults thereafter. Reliability studies comparing head-to-head different scoring criteria, recording techniques, and derivations are needed so that future scoring recommendations can be based on evidence rather than consensus opinion. We need research comparing clinical outcomes with PSG measures to better inform clinicians and families exactly what meaning a PSG has in evaluating a child's suspected sleep disorder.

Sleep and epilepsy: what we know, don't know, and need to know

Long-term video-EEG and, more recently, video-polysomnography, have provided the means to confirm and expand on the interconnections between sleep and epilepsy. Some of these relationships have become firmly established. When one of the authors (N.F.S.) presented part of this paper at a symposium on the Future of Sleep in Neurology at an American Clinical Neurophysiology Society annual meeting in 2004, the purpose was to summarize what we know, don't know, and need to know about the effects of sleep on epilepsy and epilepsy on sleep. Here we seek to summarize some of the more firmly established relationships between sleep and epilepsy and identify intriguing associations that require further elucidation.

Why a polysomnogram should become part of the diagnostic evaluation of stroke and transient ischemic attack

Neurologists need to recognize, diagnose, and treat obstructive sleep apnea (OSA) in patients with stroke or transient ischemic attack (TIA). Increasing medical evidence suggests that OSA is an independent risk factor for stroke and TIA. Stroke (or TIA) is more likely a cause, rather than a consequence, of OSA because PSG studies have shown: 1) apneas in stroke are typically obstructive, not central or Cheyne-Stokes in type; 2) apneas are just as frequent and severe in patients with either TIA or stroke; 3) OSA severity is not influenced by the acuteness or location of the stroke; 4) untreated OSA patients have more strokes, stroke morbidity, and mortality than those who are treated. OSA alone can induce hypertension, especially in younger men. A causal relationship has recently been demonstrated between OSA and hypertension. A distinctive feature of OSA-induced hypertension is loss of the normal nighttime fall in blood pressure ("nondippers"). Data from the Sleep Heart Health Study showed a dose-response association between OSA severity and the presence of hypertension 4 years later. Hypertension or ischemic heart disease usually develops in untreated patients with OSA over time without particular worsening of OSA. Studies have shown sleep itself is not a risk factor for stroke because most stroke and TIAs begin between 6 am and noon, while the individual is awake. However, OSA promptly be considered in stroke beginning during sleep because 88% of strokes that develop during sleep occur in "nondippers." Premature death in OSA patients is most often cardiovascular, but occurs while the patients are awake. The risk of myocardial infarction is increased 20-fold in untreated OSA. Treating OSA patients with continuous positive airway pressure can prevent or improve hypertension, reduce abnormal elevations of inflammatory cytokines and adhesion molecules, reduce excessive sympathetic tone, avoid increased vascular oxidative stress, reverse coagulation abnormalities, and reduce leptin levels. If all this can be achieved by a polysomnogram, then this test should become part of a neurologist's armamentarium for stroke and TIA.

Neurologic disorders masquerading as pediatric sleep problems

Neurologic disorders may present or masquerade as pediatric sleep problems and fool the pediatrician, which may delay diagnosis and treatment. Many of the sleep problems in children with neurologic disorders arise directly from primary dysfunction or delayed maturation of their sleep-wake regulation systems. It is important to realize that nocturnal frontal lobe seizures or cluster headaches can be mistaken for night terrors, and craniopharyngiomas or myotonic dystrophy may present as narcolepsy-cataplexy. Hypothalamic dysfunction may explain not only the impaired circadian rhythm disorders in children with profound mental retardation but also excessive sleepiness and hyperphagia in Prader-Willi and Kleine-Levin syndromes. Intellectually challenged children perform better, learn more, and are better behaved with sufficient restorative sleep.

Practice parameters for the use of light therapy in the treatment of sleep disorders. Standards of Practice Committee, American Academy of Sleep Medicine

These clinical guidelines were developed by the Standards of Practice Committee and reviewed and approved by the Board of Directors of the American Academy of Sleep Medicine. The guidelines provide recommendations for the practice of sleep medicine in North America regarding the use of light therapy for treatment of various sleep disorders. This paper is based on a series of articles in the Journal of Biological Rhythms and also includes evidence tables from an updated Medline review covering the period January 1994 to December 1997. Evidence is presented by grade and level. Recommendations are identified as standards, guidelines, or options. Recommendations are provided for delayed sleep phase syndrome (DSPS), advanced sleep phase syndrome (ASPS), non-24-hour sleep-wake syndrome, jet lag, shift work, dementia, and sleep complaints in the healthy elderly. Light therapy appears generally safe if used within recommended intensity and time limits. Light therapy can be useful in treatment of DSPS and ASPS. Benefits of light therapy are less clear and treatment is an option in jet lag, shift work, and non-24-hour sleep-wake syndrome in some blind patients.

The indications for polysomnography and related procedures

This paper is a review of the literature on the use of polysomnography in the diagnosis of sleep disorders in the adult. It is based on a search of MEDLINE from January 1966 through April 1996. It has been reviewed and approved by the Board of Directors of the American Sleep Disorders Association and provides the background for the accompanying ASDA Standards of Practice Committee's Parameters for the Practice of Sleep Medicine in North America. The diagnostic categories reviewed are: sleep-related breathing disorders; other respiratory disorders; narcolepsy; parasomnias and sleep-related epilepsy; restless legs syndrome and periodic limb movement disorders: insomnia; and circadian rhythm sleep disorders. Where appropriate, previously published practice parameters papers are cited and discussed. The relevant published peer-reviewed literature used as the basis for critical decisions was compiled into accompanying evidence tables and is analyzed in the text. In the section on the assessment of sleep apnea syndrome, options for estimating pretest probability to select high risk patients are also reviewed. Sleep-testing procedures other than standard polysomnography are also addressed (daytime polysomnography, split-night studies, oximetry, limited full respiratory recordings, and less-than-full respiratory recording) and treatment-related follow-up studies are discussed.

Polyclonal lymphoid tumor of the choroid plexus presenting as an intraventricular mass in a young gorilla

An unusual lymphoid lesion with reactive germinal centers, occurring in the choroid plexus of a young gorilla, is reported. It presented as a large mass in the lateral ventricle with hydrocephalus and neurological symptoms. A work-up did not reveal any underlying cause for this lesion. No similar lesion of the choroid plexus has been reported in either human or veterinary literature. Histological work-up, including flow cytometry, gene rearrangement studies and T and B cell markers, favored the lesion being a non-neoplastic lymphoid proliferation of unknown etiology. The prognosis is unknown, although, following complete removal, the animal is well and free of tumor at the time of this report.