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Our results showed that insomnia is common in patients with essential hypertension and indicate an association between insomnia and gender, known duration of hypertension and number of hypertensive drugs taken. Untreated essential hypertension insomniacs were characterized by less pronounced nocturnal fall in both systolic and diastolic blood pressure compared with non-insomniacs.

Human heart rate is moderated by the autonomous nervous system acting predominantly through the sinus node (the main cardiac physiological pacemaker). One of the dominant factors that determine the heart rate in physiological conditions is its coupling with the respiratory rhythm. Using the language of stochastic processes, we analyzed both rhythms simultaneously taking the data from polysomnographic recordings of two healthy individuals. Each rhythm was treated as a sum of a deterministic drift term and a diffusion term (Kramers-Moyal expansion). We found that normal heart rate variability may be considered as the result of a bidirectional coupling of two nonlinear oscillators: the heart itself and the respiratory system. On average, the diffusion (noise) component measured is comparable in magnitude to the oscillatory (deterministic) term for both signals investigated. The application of the Kramers-Moyal expansion may be useful for medical diagnostics providing information on the relation between respiration and heart rate variability. This interaction is mediated by the autonomous nervous system, including the baroreflex, and results in a commonly observed phenomenon--respiratory sinus arrhythmia which is typical for normal subjects and often impaired by pathology.

IntroductionSolid pseudopapillary tumor of the pancreas is extremely rare in children; it usually occurs in young women between 18 and 35 years of age. It comprises less than 3 % of pancreatic tumors. It is of low malignancy; however, it may be locally aggressive. Surgical resection is the treatment of choice and its prognosis is excellent.Case presentationTwo Caucasian girls, 15 and 12 years of age were diagnosed with tumor of the pancreas. The first patient had severe abdominal pain. In the second case the tumor was asymptomatic, detected incidentally during ultrasound. Computed tomography confirmed pancreatic mass. In the first case, apart from the tumor located in the head and the body of her pancreas, focal change in her right kidney was found, which was an indication to biopsy that confirmed solid pseudopapillary tumor. In the second patient the tumor was located in the body of her pancreas, with portal vein occlusion and well-developed collateral circulation. In the first patient a pancreatoduodenectomy (Traverso-Longmire) was performed; there was no mass in her right kidney. In the second case, distal pancreatectomy and splenectomy were performed. In both cases histopathology revealed solid pseudopapillary tumor resected radically. Our first patient’s postoperative course was uneventful. In the second case, her postoperative course was complicated by necrosis of the remaining pancreatic head that needed pancreatoduodenectomy. Follow-up at 28 and 26 months revealed no evidence of tumor recurrence or metastases on magnetic resonance imaging.ConclusionsTypical radiological appearance of solid pseudopapillary tumor is an indication for surgery. The treatment of choice is tumor resection with sparing of pancreatic tissue. In one of our two cases we performed a preoperative biopsy because of an uncharacteristic mass in her right kidney. In our second patient, necrosis of her spared pancreatic head meant that we could not preserve pancreatic tissue. Our whole diagnostic process, treatment and possible complications analysis should be of interest and noteworthy not only to surgeons as the treatment of choice is radical resection, but also to pediatric oncologists because of differentiation from other pancreatic tumors in children.

IntroductionDesmoid tumor is a rare, benign, usually asymptomatic fibromatous lesion. The etiology is unknown and the diagnosis is based on histopathological examination. The treatment is complete resection of the tumor. Pancreatic desmoid tumor is extremely rare. In the literature there have been only 11 cases described, most of them as solid or solid-cystic masses. We report the case of a patient with an isolated cystic pancreatic desmoid tumor that is, to the best of our knowledge, the second reported case.Case presentationA 13-year old Caucasian boy presented with recurrent pain of two months’ duration in the left hypochondrium of his abdomen. An ultrasound examination and computed tomography scan revealed the presence of a cystic mass located in his splenic hilum, tightly adjacent to the pancreatic tail. A splenic cyst was suspected. Operative findings showed a 10x10cm cystic mass tightly connected to the pancreatic tail and left colonic flexure, adherent to the spleen, splenic vein and artery. Distal splenopancreatectomy with en bloc resection of the left colonic flexure was performed. Histological analysis confirmed that the resection was complete. The mass had infiltrated the pancreatic parenchyma. All tumor cells were positive for anti-beta-catenin staining characteristic for desmoid tumor. No abnormalities in the spleen and colon were found.ConclusionsIsolated sporadic pancreatic desmoid tumor with cyst formation is extremely rare and its diagnosis can be difficult, especially because of uncharacteristic symptoms and radiological findings, as in our patient. This case report should be of interest not only to surgeons, as the treatment of choice is radical resection, but also gastroenterologists, considering it is in close relation with familial adenomatous polyposis, and oncologists as the reason for differentiation with other pancreatic tumors.

We present an open, parametric system for automatic detection of EEG artifacts in polysomnographic recordings. It relies on independent parameters reflecting the relative presence of each of the eight types of artifacts in a given epoch. An artifact is marked if any of these parameters exceeds a threshold. These thresholds, set for each parameter separately, can be adjusted via "learning by example" procedure (multidimensional minimization with computationally intensive cost function), which can be used to automatically tune the parameters to new types of datasets, environments or requirements. Performance of the system, evaluated on 103 overnight polysomnographic recordings, revealed concordance with decisions of human experts close to the inter-expert agreement. To make this statement well defined, we review the methodology of evaluation for this kind of detection systems. Complete source code is available from http://eeg.pl; a user-friendly version with Java interface is available from http://signalml.org.

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The aim of the study was to compare electrophysiological parameters of night sleep in narcolepsy type 1 and hypersomnia associated with a psychiatric disorder. Forty-four patients: 15 with narcolepsy type 1, 14 with hypersomnia associated with a psychiatric disorder and 15 age-and sex-matched controls participated in the study. The study subjects filled in the Athens Insomnia Scale (AIS) and the Beck Depression Inventory (BDI). The severity of daytime sleepiness was quantified subjectively using the Epworth Sleepiness Scale (ESS) and the Stanford Sleepiness Scale (SSS), and objectively using the Multiple Sleep Latency Test (MSLT). All subjects underwent polysomnography (PSG) on the two consecutive nights. The data from the second night was analysed. The slow wave activity (SWA, 1-4 Hz) was calculated for the three consecutive sleep cycles, and topographic delta power maps were plotted. In contrast to narcoleptics, psychiatric hypersomniacs had undisturbed nocturnal sleep, high sleep efficiency, normal non-rapid eye movement (NREM) and rapid eye movement (REM) sleep proportions, normal REM latency and sleep latencies on MSLT and PSG. The subjective and objective sleepiness was significantly higher in narcolepsy group than in psychiatric hypersomnia group. In all the study groups SWA was the most prominent in frontal areas, while the greatest between-group differences were found in the central areas. There were significant differences between the groups in SWA in the second NREM episode. The highest SWA was observed in the hypersomnia group, while the lowest in the narcolepsy group. Psychiatric hypersomniacs and controls did not differ in the SWA exponential decline over consecutive NREM episodes, whereas narcoleptics exhibited a steeper dissipation of sleep pressure from the first to the second NREM episode. In conclusion, narcolepsy type1 and hypersomnia associated with psychiatric disorder differ in the SWA dynamics.Narcoleptics presented with the altered dynamics of sleep homeostasis, whereas psychiatric hypersomniacs showed normal nocturnal sleep and normal sleep homeostasis.