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Biomedical subjects

R D Chervin

Publications and source records attributed to R D Chervin.

At least 19 recordsLinked to original sources
PubMed2003

Obstructive sleep apnea is related to a thalamic cholinergic deficit in MSA.

OBJECTIVE: To explore the neurochemical basis of obstructive sleep apnea (OSA) in multiple-system atrophy (MSA). METHODS: In 13 patients with probable MSA, nocturnal, laboratory-based polysomnography was used to rate the severity of OSA using the apnea-hypopnea index during sleep. SPECT with (-)-5-[123I]iodobenzovesamicol ([123I]IBVM) was utilized to measure the density of thalamic cholinergic terminals, which project from the brainstem pedunculopontine and laterodorsal tegmental nuclei. PET with (+)-[11C]dihydrotetrabenazine ([11C]DTBZ) was also used to measure the density of striatal monoaminergic terminals, which project from the brainstem. Findings in the patient group were compared with data from 12 normal control subjects scanned utilizing [123I]IBVM and 15 normal control subjects utilizing [11C]DTBZ. RESULTS: Age and gender distributions were similar in patient and control groups. The MSA subjects showed decreased [123I]IBVM binding in the thalamus (p < 0.001) and decreased mean [11C]DTBZ binding in the striatum (p < 0.0001) in comparison with the control subjects. In the MSA group, thalamic [123I]IBVM binding was inversely correlated with the severity of OSA (p = 0.011). Striatal [11C]DTBZ binding was not correlated with the severity of OSA (p = 0.19). CONCLUSION: Decreased pontine cholinergic projections may contribute to OSA in MSA.

Adult↗
PubMed2003

REM sleep behavior disorder is related to striatal monoaminergic deficit in MSA.

OBJECTIVE: To explore the neurochemical basis of REM sleep behavior disorder (RBD) in multiple-system atrophy (MSA). METHODS: In 13 patients with probable MSA, nocturnal, laboratory-based polysomnography was used to rate the severity of REM atonia loss by the percentage of REM sleep with tonically increased electromyographic (EMG) activity and the percentage of REM sleep with phasic EMG bursts. PET with (+)-[11C]dihydrotetrabenazine ([11C]DTBZ) was employed to measure the density of striatal monoaminergic terminals and SPECT with (-)-5-[123I]iodobenzovesamicol ([123I]IBVM) to measure the density of 123I]IBVM. RESULTS: Age and gender distributions were similar in patient and normal control groups. The MSA subjects showed decreased mean [11C]DTBZ binding in the striatum (p < 0.0001) and decreased [123I]IBVM binding in the thalamus (p < 0.001). Moreover, in the MSA group, striatal [11C]DTBZ binding was inversely correlated with the severity of REM atonia loss (p = 0.003). Thalamic [123I]IBVM binding, however, was not correlated to the severity of REM atonia loss. CONCLUSION: Decreased nigrostriatal dopaminergic projections may contribute to RBD in MSA.

Adult↗
PubMed2001

Periodic leg movements and sleepiness in patients evaluated for sleep-disordered breathing.

Most polysomnograms are performed because sleep-disordered breathing (SDB) is suspected, but periodic leg movements during sleep (PLMS) are frequent incidental findings, and their significance is not well understood. In a clinical series of 1,124 adult patients with suspected or confirmed SDB, we tested for an association between the rate of periodic leg movements and one important outcome, the severity of daytime sleepiness. Objective sleepiness was assessed by the Multiple Sleep Latency Test in all subjects, problem sleepiness by self-rating in 873, and subjective sleep propensity by the Epworth Sleepiness Scale in 201. Increased leg movements were associated with decreased objective sleepiness (p = 0.03) but explained less than 1% of the variance. When nocturnal arousals were scored (n = 321 subjects), rates of leg movements associated with arousals predicted less objective sleepiness (p = 0.008); rates of leg movements without arousals predicted nothing. The rates of leg movements showed no association with subjective problem sleepiness or sleep propensity. We conclude that incidental periodic leg movements during sleep are not associated with excessive daytime sleepiness, and therefore appear unlikely to contribute to this problem. Increased sleepiness may reduce the likelihood of arousal with each leg movement.

Adolescent↗
PubMed2001

Hyperactivity and polysomnographic findings in children evaluated for sleep-disordered breathing.

STUDY OBJECTIVES: Children with sleep-disordered breathing (SDB) or periodic leg movements during sleep (PLMS) often have hyperactive behavior that improves when the sleep disorder is treated. Some children with SDB also have PLMS. To determine what polysomnographic features of SDB might be associated with hyperactive behavior, we studied behavior, SDB, and PLMS in a series of patients. DESIGN: Prospective and observational. SETTING: University-based sleep disorders laboratory. SUBJECTS: Children (n=113) aged 2 to 18 years, referred for suspected SDB. INTERVENTIONS: Parents completed the hyperactivity index of the Connors' Parental Rating Scale, and results were converted to age-adjusted t-scores. Children underwent laboratory-based polysomnography, with esophageal pressure monitoring when requested (n=19) by referring physicians. RESULTS: Children with SDB (n=59) showed high hyperactivity scores (mean 59.5+/-18.3 SD, 95% C.I. [54.7, 64.2]) but these scores were no higher than those of children without SDB (59.0+/-15.1, [54.8, 63.1]). Hyperactivity showed no significant associations with the rate of apneas and hypopneas, minimum oxygen saturation, or most negative esophageal pressure (p>0.10), but was associated with the presence of 5 or more PLMS per hour (p=0.02). The rate of PLMS showed a linear association with hyperactivity among those subjects with SDB (p = 0.002), but no association among those subjects without SDB (p = 0.64). CONCLUSIONS: These findings suggest that hyperactive behavior is common among children referred for suspected SDB, regardless of the presence or severity of SDB. Current observations cannot prove causality, but they are consistent with the hypothesis that PLMS may contribute to hyperactivity and SDB may act as an effect modifier.

Adolescent↗
PubMed2001

Clinical prediction of periodic leg movements during sleep in children.

OBJECTIVE: To assess the utility of several symptoms and a questionnaire-based scale in the identification of children with periodic leg movements during sleep (PLMS). BACKGROUND: PLMS may have important consequences in some children, but the extent to which a diagnosis can be established by clinical history is unknown. METHODS: Subjects were patients aged 2-18 years who underwent polysomnography to assess for sleep-disordered breathing (SDB). Parents completed a Pediatric Sleep Questionnaire which contained items under consideration for inclusion in the desired scale. RESULTS: Subjects (n=113) had a mean age of 9.8+/-4.0 (SD) and 73 (65%) were male; 59 (52%) had SDB and 29 (26%) had five or more PLMS per hour of sleep (PLMI> or =5). Severity of SDB was not different among those with and without PLMI> or =5. Yes/no responses to several question-items--about restless legs, growing pains, leaving the bed at night, waking more than twice per night, waking feeling unrefreshed, and morning headaches--showed some association with PLMI> or =5 and were combined into a composite PLMS score artificially weighted toward the first two items. The PLMS score averaged 0.40+/-0.31 and ranged from 0.0 to 1.0; a 1 SD increase was associated with PLMI> or =5 (odds ratio=1.87, 95% confidence interval (1.15, 3.13), P=0.014) after adjustment for age, sex, and SDB severity. Sensitivity of a PLMS score>0.33 for PLMI> or =5 was 0.79, specificity was 0.56, positive predictive value was 0.38, and negative predictive value was 0.89. Internal consistency was reasonable (Cronbach's alpha=0.71), as was test-retest reliability (rho=0.62, P=0.0026, n=21 separate subjects). CONCLUSIONS: Restless legs, growing pains, sleep-maintenance insomnia, unrefreshing sleep, and morning headaches show moderate associations with polysomnographically-defined PLMS, but several other symptoms do not. These results require confirmation but suggest that clinical assessment and the PLMS score may be helpful but far from definitive.

Journal Article↗
PubMed2001

Quality of life in obstructive sleep apnea: a systematic review of the literature.

OBJECTIVE: To review the literature on obstructive sleep apnea (OSA) and health-related quality of life (HRQOL). BACKGROUND: OSA affects nearly one in four men and one in ten women aged 30-60 years in the United States. Health consequences of OSA can include neuropsychiatric and cardiovascular sequela that disrupt professional, family, and social life and negatively impact HRQOL. METHODS: We conducted a comprehensive review of the literature on HRQOL and OSA, with special attention paid to instruments developed specifically for OSA. RESULTS: Generic instruments used to study HRQOL and OSA include: Medical Outcomes Study Short Form-36, Nottingham Health Profile, Sickness Impact Profile, Functional Limitations Profile, EuroQol, and Munich Life Quality Dimension List. Specific instruments include: Calgary Sleep Apnea Quality of Life Instrument, Functional Outcomes of Sleep Questionnaire, OSA Patient Oriented Severity Index, the OSA-18, and Cohen's pediatric OSA surgery quality of life questionnaire. CONCLUSIONS: OSA patients have impaired HRQOL when compared with healthy age- and gender-matched controls. Treatment with continuous positive airway pressure appears to improve HRQOL. Other treatment modalities have not been rigorously studied. In addition, more data are needed from preference-based measures that allow conversion to utility scores, which can be used to calculate quality-adjusted life years and cost-effectiveness ratios.

Journal Article↗
PubMed2001

Assessment of sleepiness in children.

Excessive sleepiness is a common but under-recognized problem in children. This article examines the clinical and laboratory evaluation of sleepiness in children, including the use of polysomnography, the multiple sleep latency test, and other varieties of neurophysiologic testing. Where applicable, technical aspects of laboratory testing are reviewed. Alternative laboratory and neurobehavioral techniques used to investigate daytime sleepiness are also briefly covered.

Child↗
PubMed2001

Sleep problems seldom addressed at two general pediatric clinics.

OBJECTIVE: Sleep disorders can cause substantial morbidity but often remain undiagnosed among adults. We identified a series of children with sleep-related symptoms and reviewed medical chart notes for the previous 2 years to determine how often sleep problems had been addressed. DESIGN: Observational. Setting. Two university-affiliated but community-based general pediatrics clinics. PATIENTS: Children, ages 2.0 to 13.9 years, with clinic appointments. MEASURES: Parental and child responses to a validated Pediatric Sleep Questionnaire (PSQ) were used to identify patients at risk for chronic sleep-disordered breathing, periodic leg movements during sleep, insomnia, or excessive daytime sleepiness. Chart notes written within the previous 2 years were searched for sleep-related symptoms, diagnoses, or treatments. RESULTS: A total of 830 questionnaires were completed; 1395 chart notes of 86 symptomatic participants (mean age: 6.6 +/- 3.1 years; 51% male) with 103 identified sleep problems were reviewed. Fewer than 15% of patients had current chart notes that mentioned any of the PSQ-defined sleep problems; diagnoses were mentioned for 2 of 86 patients and no treatments were discussed. Among the 103 sleep problems, only 16 received mention in any past or current note; 10 had led to a diagnosis; 4 had led to intervention; and 3 were treated in a manner likely to be effective. Seventy-four of the sleep problems (72%) occurred in children whose charts did mention something about sleep, but such notations rarely related to concerns uncovered by the PSQ. CONCLUSIONS: Children with PSQ-identified sleep problems at 2 general pediatrics clinics seldom had these problems addressed, diagnosed, or treated, despite discussions about some aspect of their sleep in the large majority of cases. These findings support expansion of clinician and parent education about sleep disorders in children.

Adolescent↗
PubMed2000

The pathology of REM sleep behavior disorder with comorbid Lewy body dementia.

A patient with REM sleep behavior disorder who subsequently developed probable Lewy body dementia is now reported to have a definite pathologic diagnosis of Lewy body dementia. Examination of brain revealed Lewy bodies as well as marked neuronal loss in brainstem monoaminergic nuclei-particularly locus coeruleus and substantia nigra-that inhibit cholinergic neurons in the pedunculopontine nucleus mediating atonia during REM sleep.

Aged↗
PubMed2000

Decreased striatal dopaminergic innervation in REM sleep behavior disorder.

REM sleep behavior disorder (RBD) is a possible herald of neurodegenerative disorders with parkinsonism. The authors determined the density of striatal dopaminergic terminals with [11C]dihydrotetrabenazine PET in six elderly subjects with chronic idiopathic RBD and 19 age-appropriate controls. In subjects with RBD, there were significant reductions in striatal [11C]dihydrotetrabenazine binding, particularly in the posterior putamen.

Aged↗
PubMed2000

Sleep disordered breathing in patients with cluster headache.

OBJECTIVE: To study subjects with active or inactive cluster headache (CH) for occult sleep disordered breathing (SDB). BACKGROUND: CH frequently occurs during sleep. The authors previously found that symptoms of SDB predicted reported occurrence of CH in the first half of the night, which suggested that CH could be triggered in some cases by unrecognized SDB. METHODS: The authors performed polysomnography in 25 adults (22 men) with CH. Subjects were not selected for any sleep-related complaint. In addition to standard measures, studies included monitoring of end-tidal carbon dioxide (n = 22), and esophageal pressure (n = 20). RESULTS: The rate of apneas and hypopneas per hour of sleep was >5 in 20 subjects (80%; 95% CI, 64% to 96%), minimum oxygen saturation was <90% in 10 subjects, maximum negative esophageal pressure ranged from -13 to -65 cm H2O, and maximum end-tidal carbon dioxide was > or =50 mm Hg in eight subjects. The eight subjects with active (versus inactive) CH at the time of study had higher maximum end-tidal carbon dioxide levels (50 +/- 3 versus 44 +/- 5 mm Hg; p = 0.0007). More severe oxygen desaturation was associated with reports that CH typically occurred in the first half of the nocturnal sleep period (p = 0.008). CONCLUSIONS: SDB occurred in the majority of patients with CH. Evaluation of a patient with CH should include consideration that SDB may be present.

Adult↗
PubMed2000

Parkinsonism after correction of hyponatremia with radiological central pontine myelinolysis and changes in the basal ganglia.

Parkinsonism has been rarely described following central pontine and extrapontine myelinolysis. We report a case of parkinsonism developing following rapid correction of hyponatremia with radiological evidence of central pontine myelinolysis and changes in the basal ganglia. A 56-year-old man developed drooling and bilateral hand tremors 3 weeks after correction of hyponatremia from 103 to 125 mmol/L over 14 h. He had a prominent 6 Hz resting tremor which worsened with action and mild cogwheel rigidity. Magnetic resonance imaging (MRI) showed changes consistent with central pontine myelinolysis and increased signal on T1-weighted images in the putamen bilaterally. His tremor responded well to L-dopa therapy. There have been several other cases of parkinsonism developing after central pontine/extrapontine myelinolysis. Increased signal in the basal ganglia on T1-weighted images has been described in another case of central pontine myelinolysis imaged about the same time after sodium correction as our case.

Antiparkinson Agents↗
PubMed2000

Sleep onset REM periods during multiple sleep latency tests in patients evaluated for sleep apnea.

Although 2 or more sleep onset rapid eye movement (REM) periods (2omSOREMPs) on a Multiple Sleep Latency Test (MSLT) raise the possibility of narcolepsy, patients with obstructive sleep apnea (OSA) also can have 2omSOREMPs, which may then cause diagnostic uncertainty. To explore what features among OSA patients predict 2omSOREMPs on an MSLT that follows nocturnal polysomnography, we reviewed data from 1,145 consecutively studied patients suspected or confirmed to have OSA rather than narcolepsy. Overall, 4.7% of the subjects had 2omSOREMPs. Variables that were independently predictive of 2omSOREMPs in logistic regression models included male gender (OR = 4.4, 95% CI = 1.9 to 12.7), a 5-min decrease in the MSLT-derived mean sleep latency (OR = 1.9, 95% CI = 1.3 to 2.8), a 90-min decrease in nocturnal latency to REM sleep (OR = 1.6, 95% CI = 1.1 to 2.5), and a 15-unit decrease in minimal recorded oxygen saturation (OR = 1.6, 95% CI = 1.3 to 2.0). We conclude that among patients suspected or confirmed to have OSA, one or more of these four variables-male sex, sleepiness, nocturnal REM sleep latency, and extent of oxygen desaturation-could reflect neurophysiological mechanisms responsible for 2omSOREMPs. Consideration of these variables, and especially gender, may be useful in clinical practice when 2omSOREMPs are found unexpectedly.

Adolescent↗
PubMed2000

Sleepiness, fatigue, tiredness, and lack of energy in obstructive sleep apnea.

STUDY OBJECTIVES: Sleepiness is a key symptom in obstructive sleep apnea syndrome (OSAS) and can be objectively assessed with a multiple sleep latency test (MSLT). We studied the terms that patients prefer to describe their symptoms-sleepiness, fatigue, tiredness, or lack of energy-and how these terms relate to objective findings. DESIGN: Observational. SETTING: University-based sleep laboratory. PATIENTS: Consecutive OSAS patients referred for diagnostic polysomnography and an MSLT. METHODS: Data were obtained from sleep studies and questionnaires. RESULTS: Subjects included 117 men and 73 women, with a mean (+/- SD) age of 49 +/- 13 years, an apnea and hypopnea rate of 32 +/- 28/h of sleep, and an MSLT mean sleep latency of 7 +/- 5 min. Subjects more frequently reported problems with fatigue, tiredness, and lack of energy than sleepiness (57%, 61%, and 62% vs 47%). When required to select the one most significant symptom, more patients chose lack of energy (about 40%) than any other problem, including sleepiness (about 22%). Objective measures of sleepiness and apnea severity showed little or no association with any symptom, but female gender showed significant associations with each. CONCLUSIONS: Complaints of fatigue, tiredness, or lack of energy may be as important as that of sleepiness to OSAS patients, among whom women appear to have all such complaints more frequently than men. The diagnosis of OSAS should not be excluded based only on a person's tendency to emphasize fatigue, tiredness, or lack of energy more than sleepiness.

Circadian Rhythm↗