Focal and global cortical hypometabolism in patients with newly diagnosed infantile spasms.

OBJECTIVE: To evaluate the occurrence and prognostic importance of focal defects in cerebral cortical glucose metabolism in infants with newly diagnosed symptomatic and cryptogenic infantile spasms. PATIENTS AND METHODS: Ten children with symptomatic and seven with cryptogenic infantile spasms underwent MRI, video-EEG, and PET using fluorodeoxyglucose as a tracer within 2 weeks of diagnosis. PET was repeated at 1 year of age in 12 patients. RESULTS: Cortical hypometabolic foci were found in 13 children (77%) with newly diagnosed spasms (six cryptogenic and seven symptomatic). The hypometabolic foci disappeared in seven of nine reexamined at age 1. The occipital foci disappeared in all (n = 6). Focal findings on PET correlated well with focal findings on video-EEG. There was no difference in quantitative cortical or subcortical glucose metabolic rate at the onset of infantile spasms between children with cryptogenic and symptomatic etiology of spasms. The glucose metabolic rate at the onset of spasms or focal lesions in glucose metabolism did not have prognostic value for seizure outcome. CONCLUSIONS: Infantile spasms are often associated with transient cortical, especially occipital, hypometabolic foci that are not necessarily associated with structural lesions and do not indicate a poor prognosis.

Resistance to exercise-induced increase in glucose uptake during hyperinsulinemia in insulin-resistant skeletal muscle of patients with type 1 diabetes.

Insulin and exercise have been shown to activate glucose transport at least in part via different signaling pathways. However, it is unknown whether insulin resistance is associated with a defect in the ability of an acute bout of exercise to enhance muscle glucose uptake in vivo. We compared the abilities of insulin and isometric exercise to stimulate muscle blood flow and glucose uptake in 12 men with type 1 diabetes (age 24 +/- 1 years, BMI 23.0 +/- 0.4 kg/m(2)) and in 11 age- and weight-matched nondiabetic men (age 25 +/- 1 years, BMI 22.3 +/- 0.6 kg/m(2)) during euglycemic hyperinsulinemia (1 mU. kg(-1). min(-1) insulin infusion for 150 min). One-legged exercise was performed at an intensity of 10% of maximal isometric force for 105 min (range 45-150). Rates of muscle blood flow, oxygen consumption, and glucose uptake were quantitated simultaneously in both legs using [(15)O]water, [(15)O]oxygen, [(18)F]-2-fluoro-2-deoxy-D-glucose, and positron emission tomography. Resting rates of oxygen consumption were similar during hyperinsulinemia between the groups (2.4 +/- 0.3 vs. 2.0 +/- 0.5 ml. kg(-1) muscle. min(-1); normal subjects versus patients with type 1 diabetes, NS), and exercise increased oxygen consumption similarly in both groups (25.3 +/- 4.3 vs. 20.1 +/- 3.0 ml. kg(-1) muscle. min(-1), respectively, NS). Rates of insulin-stimulated muscle blood flow and the increments in muscle blood flow induced by exercise were also similar in normal subjects (129 +/- 14 ml. kg(-1). min(-1)) and in patients with type 1 diabetes (115 +/- 12 ml. kg(-1). min(-1)). The patients with type 1 diabetes exhibited resistance to both insulin stimulation of glucose uptake (34 +/- 6 vs. 76 +/- 9 micromol. kg(-1) muscle. min(-1), P < 0.001) and also to the exercise-induced increment in glucose uptake (82 +/- 15 vs. 162 +/- 29 micromol. kg(-1) muscle. min(-1), P < 0.05). We conclude that the ability of exercise to increase insulin-stimulated glucose uptake in vivo is blunted in patients with insulin-resistant type 1 diabetes compared with normal subjects. This could be caused by either separate or common defects in exercise- and insulin-stimulated pathways.

Does dialysis therapy improve autonomic and peripheral nervous system abnormalities in chronic uraemia?

OBJECTIVES: Autonomic nervous system (ANS) dysfunction and peripheral neuropathy occur in patients with chronic renal insufficiency. Adequate renal replacement therapy should prevent development or correct these abnormalities. DESIGN AND SUBJECTS: We studied retrospectively ANS and peripheral neuropathy in 32 patients with chronic uraemia who received either haemodialysis (16) or peritoneal dialysis (16) therapy, and compared the observed dialysis efficiency with changes in neurological function. METHODS: Heart rate variability (HRV) time domain indices and peripheral sensory nerve conduction studies were followed for a mean of 2.9 years. The adequacy of haemodialysis (HD) efficiency was estimated by Kt/V, an index of fractional urea clearance. Adequacy of continuous ambulatory peritoneal dialysis (CAPD) was estimated on the basis of the patient's wellbeing and nutritional status as excellent, satisfactory or poor. Based on observed changes in HRV time domain measures, the observations were divided in three subgroups: improved, unchanged or deteriorated. RESULTS: The peripheral sensory nerve conduction studies were abnormal in 38% of the patients and did not change significantly during the study. Improvement in HRV time domain measures occurred in HD patients with mean Kt/V > 1.20 or in CAPD patients with satisfactory or excellent response to dialysis treatment. Values of Kt/V < 0.85 in HD patients were associated with progressive deterioration of autonomic neuropathy. Diabetic patients (n = 4) differed from others as their HRV was grossly abnormal and did not improve. CONCLUSIONS: The adequacy of haemodialysis is a predictor of improvement of cardiac autonomic nervous function in chronic uraemia. The same trend of improvement was seen also in CAPD patients.

Distributed clinical neurophysiology.

We have developed a consultation forum for clinical neurophysiology in Finland. The system connects local digital electroencephalography (EEG) recording and analysing networks using a high-speed asynchronous transfer mode (ATM) network. Clinicians can obtain a second opinion using interactive data and video consultations or using data-only consultations. In addition, the system can be used for off-line review of pre-recorded data. During a one-month evaluation, 66 EEG recordings were made altogether in Satakunta Central Hospital and consultations were required on 12 occasions. Nine of them were data-only consultations and three were data and video consultations. A data consultation lasted 15-20 min and a data and video consultation 35-45 min. Clinically, there were numerous benefits for the hospitals. The system established a link to a centre of excellence for second opinions or continuing education. It also helped with on-duty arrangements and enabled the construction of national data banks.

Sleep disorders in patients with severe nasal obstruction due to septal deviation.

The role of nasal obstruction in etiology of the sleep apnea disease is controversial in literature. Forty-six subjects (3 women, 43 men) with severe nasal obstruction due to septal deviation were evaluated. The examination included case history, clinical ORL examination by ENT specialist, rhinomanometry and whole night sleep recording (SCSB, oximetry, EKG). Mean age of the patients was 40.0 years (from 17 to 68 years) and body mass index 26.0 kg/m2 (from 20.3 to 34.6 kg/m2). The chief complaint of the patients was a severe nasal obstruction. Thirty-one patients (67%) had also heavy disturbing snoring, and apnea periods during sleep were reported by 10 cases. The evaluation of the sleep recordings revealed 12 cases with partial upper airway obstruction (26%), 1 case with severe airway obstruction, 1 case with mixed type of obstructive apnea and 3 cases with periodic limb movements. Evaluation of the oxygen desaturation of the blood revealed only 6 cases with significant disturbance (pO2 below 90% level). As a final result we conclude that severe nasal obstruction can lead to breathing disturbance during sleep.

Detection of periodic leg movements with a static-charge-sensitive bed.

We evaluated the performance of the static-charge-sensitive bed (SCSB), a non-invasive movement sensor, in detecting nocturnal periodic movement activity using simultaneous bilateral anterior tibialis electromyography (EMGat) as a reference. Two different study setups were used, one with 500 random record extracts, another with 10 continuous recordings. The inter-rater reliability between two independent scorers was 0.92 in scoring EMGat and 0.91 in scoring SCSB. In an epoch based analysis, depending on the study setup and scorer, the sensitivity of the SCSB to detect periodic leg movements was 0.81-0.94 whereas the specificity was 0.84-0.89. In a movement-by-movement analysis, despite incomplete concordance between the two methods the total number of movements per hour were comparable. Our findings support the use of the SCSB as a non-invasive alternative to anterior tibialis EMG recordings to reveal the presence of nocturnal periodic movement activity and estimate its frequency.

Sleep apnea syndrome in children--secondary to adenotonsillar hypertrophy?

In this study we investigated the relationship between the size of adenoids and/or tonsils and obstructive sleep apnea syndrome (OSAS) in 19 children aged 3 to 7 years. After clinical examination by an ENT specialist, electrocardiogram (ECG), vectorcardiogram (VCG) and echocardiogram (EC) were performed while the patients were awake, and static charge sensitive bed (SCSB) method recording (noninvasive monitoring of ballistocardiogram, respiration and body movements) while asleep. After adenoidectomy and/or tonsillectomy, the volume of the tonsils and the adenoids was determined. RVH was found in 4 out of 19 children (21%). RVH findings correlated highly with the number of apneas but, surprisingly, not with measured adenotonsillar size in those children. However, at 6 months of follow-up, the VCG and EC changes had returned to normal. These results suggest that RVH is more common in children suffering from upper airway obstruction than previously believed, and that factors other than adenotonsillar size also have an influence on upper airway obstruction.

Sleep disturbances in hypertension: a double-blind study between isradipine and metoprolol.

This was a comparison of the effects of isradipine and metoprolol on sleep apnea syndrome in 12 hypertensive men who were habitual snorers. Each patient received double-blind isradipine 1.25-2.5 mg twice daily or metoprolol 50-100 mg twice daily after a 4-week placebo period. Static charge-sensitive bed examination was performed during the placebo period and 5-7 weeks after starting treatment. The number of obstructive breathing patterns was increased by metoprolol in five patients, remained the same with isradipine in four, and was decreased by metoprolol in one patient and by isradipine in two. Obstructive patterns increased in the metoprolol group from 24 +/- 26% to 32 +/- 31% and decreased in the isradipine group from 21 +/- 23% to 19 +/- 25% (p less than 0.05, Mann-Whitney U test). Neither drug had a significant effect on blood pressure values. There was no significant difference in oxygen desaturation or in the amount of quiet sleep in either treatment group. On the basis of these results, it would appear that isradipine is more suitable than metoprolol for the treatment of hypertension in patients who are habitual snorers.

Pathological heart rate responses associated with body movements in neurologically damaged infants during sleep.

Simultaneous electrocardiogram (ECG) and static charge sensitive bed (SCSB) method recordings were carried out in fifteen healthy and twenty-one neurologically damaged infants during sleep at the age of one week, one month and three months. The SCSB method allows continuous long-term recording of body movements without electrodes connected to the subject. The heart rate response to body movements was studied. Healthy newborns had clear heart rate (HR) acceleration response to body movements. A rapid HR deceleration response occurred at the end of body movements. In the neurologically damaged infants the HR response to body movements was significantly hyperactive or delayed. The abnormal heart rate acceleration-deceleration response to body movements in damaged infants can best be explained by disturbed function of the autonomic nervous system.

Subglottic stenosis in neonates and children. Clinical findings and therapy.

From 1978 through 1987, acquired subglottic stenosis was confirmed endoscopically in 31 children. The mean gestational age of the children was 32 weeks and mean birthweight 2,180 g. Of the children 84% were below 12 months of age at the time of diagnosis. Respiratory distress syndrome was confirmed in 17 children. Before diagnosis, 97% of the children had been treated by endotracheal intubation for ventilatory support, the mean duration of intubation being 37 days. In 10 children, subglottic stenosis was mild and mature and these children were followed up only. Endolaryngeal prosthesis was employed in 2 children and laryngotomy with autogenous bone graft in 5 children. Mean follow-up time was 5 years 4 months. At follow-up, 18 of the children showed good or excellent results.

SCSB method compared to EEG-based polygraphy in sleep state scoring of newborn infants.

Knowledge of the sleep state is important in physiological studies since many physiological variables show different properties in different sleep states. The recently developed static charge sensitive bed (SCSB) method allows long-term recordings of body movements, respiration and ballistocardiogram without electrodes attached to the subject. The recordings are easy to carry out and they do not disturb the subject in any way. The recorded variables are basic characteristics of different sleep states. SCSB-recordings and electroencephalography (EEG) based polygraphy as well as blind sleep state scoring were carried out in 8 newborn infants. The positive correlation between SCSB-scoring and EEG-based polygraphy scored by two clinical neurophysiologists was 68.1 and 64.1%. Only in 2% of all epochs was active sleep scored as quiet sleep or vice versa. The results indicate the usefulness of the SCSB method in sleep state scoring of newborn infants.

Pediatric bronchoscopy. A report of methodology and results.

Data for this article were obtained from a retrospective analysis of 386 pediatric bronchoscopies from 1979 through 1986. Endoscopic procedures were carried out under general anesthesia using a rigid open bronchoscope. There were 235 boys (61%) and 151 girls (39%). The mean age was 2 years, 3 months. Eight percent of the girls were under 1 month of age, compared with only 4 percent of the boys. The lightest patient weighed 650 g. In children under 1 year of age, the most common indications were dyspnea (32%) and anomaly or suspicion of anomaly (20%). In children over 1 year of age suspected foreign body (32%) and recurrent respiratory infections (30%) were the most common indications. In 15 percent of patients, laryngomalacia and/or an abnormal epiglottis was confirmed. Subglottic stenosis, congenital or acquired, was confirmed in 9 percent and tracheal compression in 12 percent of cases. Seventeen percent of the children showed totally normal findings. There were only eight complications in the whole series and no death or cardiac arrest. The authors confirm the safety of bronchoscopy when careful attention is paid to preoperative investigations, selection of the instruments used, and postoperative care.

Body movements during sleep in healthy and neurologically damaged infants.

The body movements of sixteen healthy and twenty-one neurologically damaged infants were recorded during sleep on the static charge sensitive bed (SCSB). The SCSB method allows long-term monitoring of body movements, respiration and ballistocardiogram. Different body movement variables were estimated at the ages of 1 week, 1 month and 3 months. The results showed a constant duration and number of body movements during active and quiet sleep at each studied age both in healthy and neurologically damaged infants. A decreasing tendency in the number of body movements could only be seen if no differentiation between sleep states was made. No statistically significant differences were found between healthy and neurologically damaged infants in any of the variables. The results suggest that quantitative changes--the duration and number--in motor patterns during sleep are inadequate criteria for differentiation between healthy and neurologically damaged infants.

Pediatric bronchoscopy during a 17-year period.

From 1969 through 1985, 1032 pediatric bronchoscopies were performed on a total of 748 children under 16 years of age. Of the children 27.4% were under 6 months of age and the smallest patient weighed 600 g. Rigid bronchoscopes with a diameter ranging from 2.5 to 6 mm were used. A flexible fiberoptic bronchoscope with a diameter of 3.5 mm was used only occasionally, mostly for the diagnosis of laryngeal dynamics. All the endoscopies were performed under general anesthesia, except for some laryngoscopies performed with a flexible bronchoscope. The most common indications for bronchoscopy were suspected foreign body (16.7%), stridor (14.5%), recurrent respiratory infections (12.3%) and dyspnoe (9.6%). Laryngomalacia was observed in 13.8% of the children investigated and in patients with inspiratory stridor laryngomalacia was diagnosed in 39.8% of the cases. Subglottic stenosis was confirmed in 7.0% of the children. Tracheal compression was found in 10.8% and tracheal stenosis in 2.5% of the cases. Bronchiectasis was observed in 2.5% and tuberculosis in only 0.5% of the cases. Bronchoscopy was completely normal in only 10.6% of the patients investigated. The complications of pediatric bronchoscopy in this series were infrequent.

Radiological parameters of the bony nasopharynx and the adenotonsillar size compared with sleep apnea episodes in children.

The role of enlarged adenoids and tonsils in recurrent respiratory infections and upper airway obstruction has become well-established earlier. In this study we investigated the relationship between the X-ray properties of the nasopharynx and the sleep quality by using a new sleep registration method: The Static Charge Sensitive Bed (SCSB). The estimation of the bony nasopharyngeal dimensions, the measurement of adenotonsillar volume and the sleep recordings were performed as adenoidectomy, tonsillectomy or adenotonsillectomy in hospitalized children. A surprisingly high frequency of sleep apnea episodes was found in sleep recordings of about 8 h. No correlations could be established between the X-ray anatomical estimates and sleep apnea episodes.

Heart rate response related to body movements in healthy and neurologically damaged infants during sleep.

Sixteen infants were studied with the static charge sensitive bed (SCSB) method. This method is newly developed for neonatal recordings and it allows recording of body movements, respiration and of the ballistocardiographic signal. Eight healthy newborn infants and eight infants with clear neurological dysfunction were recorded and the heart rate acceleration-deceleration responses to body movements during sleep were studied. Healthy infants had a constant heart rate response to body movements but infants with neurological symptoms had either too weak or hyperactive reactions. This finding can be explained by abnormal function of the autonomic nervous system in infants with disturbance of the central nervous system.