Computed diffusion-weighted imaging in patients with transient neurovascular symptoms with and without ischemic infarction.

PURPOSE: Detection of ischemic lesions in patients with transient neurovascular symptoms is relevant for the estimation of the risk of a subsequent stroke and etiological classification. To improve detection rates, different technical approaches have been used, such as diffusion-weighted imaging (DWI) with high b-values or higher magnetic field strength. Here, we sought to investigate the value of computed DWI (cDWI) with high b-values in these patients. METHODS: From an MRI report database we identified patients with transient neurovascular symptoms who underwent repeated MRI including DWI. cDWI was calculated with a monoexponential model with high b-values (2000, 3000, and 4000 s/mm2) and compared to the routinely used standard DWI with regard to presence of ischemic lesions and lesion detectability. RESULT: Overall 33 patients with transient neurovascular symptoms (71 [IQR 57-83.5] years; 21 [63.6%] male) were included. On DWI, acute ischemic lesions were observed in 22 (78.6%). Acute ischemic lesions were observed in 17 (51.5%) patients on initial DWI, and in 26 (78.8%) patients on follow-up DWI. Lesion detectability was rated significantly better on cDWI at 2000s/mm2 compared to standard DWI. In 2 (9.1%) patients, cDWI at 2000s/mm2 revealed an acute ischemic lesion proven on follow-up standard DWI which was not detected with certainty on the initial standard DWI. CONCLUSION: cDWI might be a valuable addition to routinely acquired standard DWI in patients with transient neurovascular symptoms since its use might result in improved ischemic lesion detection. A b-value of 2000s/mm2 seems most promising for clinical practice.

GLOS and HARM in patients with transient neurovascular symptoms with and without ischemic infarction.

BACKGROUND AND PURPOSE: Gadolinium leakage in ocular structures (GLOS) on fluid attenuated inversion recovery images (FLAIR) is a novel imaging marker in acute ischemic stroke and other neurological disorders. METHODS: In patients with transient neurovascular symptoms who underwent repeated MRI with intravenous contrast agent administration, the presence of acute ischemic lesions on diffusion-weighted images (DWI) as well as the frequency and pattern of blood-brain barrier and blood-retina barrier impairment as demonstrated by the hyperintense acute reperfusion marker (HARM) and GLOS respectively on postcontrast FLAIR were evaluated. RESULTS: Overall 28 patients with transient neurovascular symptoms (median age 70.5 years; 18 (64.3%) male) were included. Follow-up MRI was performed within 35 (IQR 21-47) hours after the initial MRI. On DWI, acute ischemic lesions were observed in 22 (78.6%). On contrast-enhanced FLAIR, GLOS was observed in 12 (42.9%) patients: in 1 (3.6%) only in the anterior chamber, and in 11 (39.3%) in the anterior chamber and vitreous body. HARM was observed in 3 (10.7%) patients. In one patient without ischemic lesion on DWI or HARM on FLAIR, GLOS was observed in the anterior chamber and vitreous body. Presence of GLOS was associated with higher age (p = 0.04) and detection of HARM (p = 0.03). CONCLUSIONS: In patients with transient neurovascular symptoms, GLOS is a frequent finding and associated with HARM on contrast-enhanced FLAIR. As GLOS was observed in one patient without an ischemic lesion or HARM, it might be useful as an additional imaging marker.

Asymmetrical Gadolinium Leakage in Ocular Structures in Stroke Due to Internal Carotid Artery Stenosis or Occlusion.

PURPOSE: Gadolinium leakage in ocular structures (GLOS) on fluid-attenuated inversion recovery images (FLAIR) is a novel imaging marker in acute ischemic stroke. The present study sought to investigate the frequency and pattern of blood-retina barrier impairment in acute ischemic stroke due to internal carotid artery (ICA) stenosis or occlusion as demonstrated by GLOS. METHODS: From a magnetic resonance imaging (MRI) report database patients were identified with acute ischemic stroke due to ICA stenosis/occlusion who underwent repeated MRI with intravenous contrast agent administration and FLAIR and MR angiography (MRA). On FLAIR the presence of GLOS was noted in the vitreous body. RESULTS: Overall 51 patients with a median age of 70 years (interquartile range, IQR 63-77 years) were included. Of these, 22 (43.1%) patients had an ICA stenosis and 29 (56.9%) an ICA occlusion. On contrast-enhanced FLAIR, GLOS was observed in 29 (56.9%) patients: in 7 (13.7%) unilateral, in 15 (68.2%) bilateral asymmetrical and in 7 (31.8%) bilateral symmetrical. In unilateral asymmetrical GLOS, more pronounced enhancement was always found ipsilateral to ICA stenosis/occlusion. In 4 (5.9%) patients with asymmetrical GLOS a pre-existing signal increase in the vitreous body was found on native FLAIR. The presence of GLOS was associated with an impaired collateralization through the circle of Willis (p < 0.001) and external carotid artery branches (p = 0.03). CONCLUSION: In patients with ischemic stroke due to ICA stenosis/occlusion, GLOS is frequent, commonly unilateral or bilateral asymmetrical, and in some patients associated with pre-existing ocular signal abnormalities. An insufficient collateralization may contribute to the development of unilateral/asymmetrical GLOS.

A conceptual framework for an oral cancer awareness campaign in Northern Germany - Challenges in campaign development and assessment.

Initial impetus for action: Oral cancer is still an underestimated disease in terms of incidence as well as mortality rates; it requires urgent prevention and early detection. At present, there is no best-practice systematic approach to raising awareness and informing the public about about this type of cancer in Germany. This article describes a framework that covers the significant stages of conceptual development and campaign design to promote oral cancer awareness in Germany. Solution: The challenges of the development, as well as evaluation of an oral cancer awareness campaign are shared in this article. Four key stages of the campaign are defined: (1) mass media, (2) target groups, (3) health care professionals, and (4) epidemiology. For each section, the following levels of assessment are proposed: (a) campaign development (formative assessment), (b) controlling and optimising campaign implementation (process assessment) and (c) measuring outcomes (summative assessment). Outcome: A process-oriented assessment concept for each of the four campaign sections was developed and merged to form a matrix, which includes each of the above sections regarding the prevention and early detection of oral cancer, as well as the three stages of campaign assessment. Future implications and learning points: The conceptual framework demonstrated that systematic planning and evaluation of different components helped to describe and evaluate an oral cancer campaign: For future campaigns, the use of a matrix covering different campaign targets as well as the entire campaign process, is recommended as a basis for campaign design and evaluation.

Gadolinium leakage in ocular structures: A novel MRI finding in transient global amnesia.

BACKGROUND AND PURPOSE: We investigated the frequency and pattern of blood-brain barrier as well as blood-retina barrier impairment in transient global amnesia (TGA) as demonstrated by hyperintense acute reperfusion marker (HARM) and gadolinium leakage in ocular structures (GLOS) respectively on fluid attenuated inversion recovery images (FLAIR). METHODS: Patients with TGA who underwent repeated MRI after intravenous contrast agent administration were identified and the presence of GLOS in the anterior chamber and vitreous body and HARM noted on FLAIR. RESULTS: Overall 10 patients (IQR 64.25-71.75 years; 4 (40%) patients were male) were included. On contrast-enhanced FLAIR, GLOS was observed in 3 (30%) patients; in all of these in the anterior chamber and vitreous body as well as bilateral and symmetrical. HARM was observed in none of the patients. Frequency of hippocampal DWI lesions, as well as extent of age related white matter lesions did not differ significantly between patients with and without GLOS. CONCLUSIONS: In contrast to HARM, GLOS is a relatively common finding in TGA patients. As GLOS is thought to share its pathophysiology at least to some extent with HARM and is associated with HARM in ischemic stroke, it might be used as surrogate marker for blood-brain barrier impairment in TGA.

Hippocampal infarction: Identification of three new types.

BACKGROUND AND PURPOSE: Hippocampal infarction (HI) is common but yet still not comprehensively studied. In the present study, we aimed to identify novel HI patterns and to describe additional ischemic lesions outside the hippocampus to draw conclusions regarding the underlying vessel occlusion. METHODS: In 222 patients (mean age 69.9 (±13.6) years; 129 (58.1%) male, 93 (41.9%) female) with HI, diffusion-weighted images were analyzed with emphasis on HI patterns and associated ischemic lesions outside the hippocampus. HI were classified as type 1 (complete), 2 (lateral), 3 (dorsal), and 4 (circumscribed). Further possible HI patterns were defined and classified as type 5 (ventral), 6 (ventrolateral), and 7 (dorsolateral). RESULTS: Unilateral HI was found in 218 (98.2%) patients. In these, type 5 and 6 were identified in 5 (2.3%) patients, and type 7 in 8 (3.7%) patients respectively. Type 1 was found in 62 (28.4%), 2 in 53 (24.3%), 3 in 57 (26.1%), and 4 in 28 (12.8%) patients. Further ischemic lesions were found in the territory of the anterior cerebral artery (3.6%), middle cerebral artery (14.9%), anterior choroidal artery (AChA) (7.2%), posterior cerebral artery (89.6%), and in the brainstem (6.3%) and cerebellum (20.3%). Type 5 and 6 were significantly associated with acute ischemic lesions in the AChA territory (6/10 (60%) vs. 11/200 (5.5%), P<0.001). CONCLUSIONS: We identified three novel HI types. Probably, type 5 and 6 can be attributed to occlusion of the AChA. Overall, these HI types are rare, possibly due to a better collateralization in the case of AChA occlusion.

Isolated punctuate hippocampal infarction and transient global amnesia are indistinguishable by means of MRI.

Background Small punctuate lesions in the hippocampus on diffusion-weighted images are a typical finding in transient global amnesia. Consequently, it has been suggested that diffusion-weighted images findings might corroborate the diagnosis of transient global amnesia. However, isolated punctuate hippocampal infarction might be a differential diagnosis of transient global amnesia. Aim Evaluation of isolated punctuate hippocampal infarction frequency and comparison of its clinical presentation and MRI findings to transient global amnesia. Methods From an MRI database, we identified 10 patients with isolated punctuate hippocampal infarction and compared these to 12 patients with transient global amnesia with diffusion-weighted images lesion with regard to clinical symptoms and MRI findings. Results Disorientation and memory deficits were more common in transient global amnesia patients, whereas dysphasia/aphasia and vertigo were more common in hippocampal infarction patients. MRI findings in isolated punctuate hippocampal infarction and transient global amnesia did not differ significantly, neither regarding the affected hemisphere, lesion distribution, size, nor relative ADC values. Conclusions Differentiation of isolated punctuate hippocampal infarction and transient global amnesia based on neuroimaging findings is not possible. Thus, in the case of isolated punctuate hippocampal diffusion-weighted images lesions the final diagnosis of hippocampal infarction or transient global amnesia should be based on the clinical presentation.

[Hyponatremia-induced life-threatening cerebral edema after ecstasy use]. / Hyponatriämieinduziertes lebensbedrohliches Hirnödem nach Ecstasykonsum.

Ecstasy, a psychoactive amphetamine derivative, is a popular party drug. We report the cases of 2 young adults who developed cerebral edema due to hyponatremia. One patient was released from the hospital without any sequelae, whereas the second patient died due to cerebral edema. Severe cases of symptomatic hyponatremia after ecstasy consumption are described in the literature with partially fatal clinical outcomes. Thus, physicians should be aware of early and consequent control of the sodium and choose an interdisciplinary treatment decision.

The pre-interventional psychiatric history - an underestimated confounder in benign intracranial lesions studies.

OBJECTIVES: The current study was designed to analyze the influence of a positive pre-interventional psychiatric history on the quality of life (QOL) after successful treatment of benign intracranial extra-cerebral lesions. METHODS: Patients treated due to meningioma WHO I or unruptured intracranial aneurysms in two German neurosurgical centers between 2007 and 2013 were screened for exclusion criteria including malignant/chronic diseases, recurrence of the tumor/aneurysm and neurological deficits among others. 131 patients who met the criteria of an objectively unaffected health status were included. The pre-interventional psychiatric histories and the rates of post-interventional headaches, sleeping disorders, symptoms of chronic fatigue syndrome (CFS), post-traumatic stress disorder (PTSD) and QOL were determined by questionnaires which were mailed to the patients. RESULTS: 103 patients returned the questionnaires. Despite the objectively unaffected health status, the patients with a positive pre-interventional psychiatric history demonstrated a post-interventionally significantly lower QOL (p=0.002), a significantly higher Pittsburgh Sleep Quality Index sum score (p=0.009), as well as significantly higher rates of symptoms of a chronic fatigue syndrome (p=0.003) and PTSD (p=0.024), compared to the patient collective with a negative pre-interventional psychiatric status. CONCLUSION: The results of the current study demonstrate the importance of taking the pre-interventional psychiatric history as a significant and independent confounder into consideration when evaluating the outcome after treatment of benign intracranial extra-cerebral lesions. A pre-interventional psychiatric screening and an early psychological intervention might help to improve the overall outcome after successful treatment of such lesions.

Patient characteristics support unfavorable psychiatric outcome after treatment of unruptured intracranial aneurysms.

INTRODUCTION: Previous studies demonstrated an unfavorable psychological outcome after treatment of unruptured intracranial aneurysms despite an objectively favorable clinical and radiological outcome. The current study was therefore designed to analyze the psychiatric vulnerability of this specific patient collective. MATERIALS AND METHODS: Patients treated for a WHO grade I meningioma and incidental intracranial aneurysms in two German neurosurgical centers between 2007 and 2013 were screened for exclusion criteria including malignant/chronic diseases, recurrence of the tumor/aneurysm after more than 12 months and focal neurological deficits, among others. Seventy-five meningioma patients (M) and 56 incidental aneurysm patients (iA) met the inclusion criteria. The past medical psychiatric history, post-morbid personality characters and coping strategies were determined by questionnaires mailed to the patients in a printed version (Brief COPE, Big Five Personality Test). RESULTS: Fifty-eight M and 45 iA patients returned the questionnaires. Patients with iA demonstrated significantly higher pre-interventional rates of depressive episodes (p = 0.002) and psychological supervision (p = 0.038). These findings were especially aggravated in iA patients who received their cranial imaging for unspecific symptoms such as dizziness, headaches or tinnitus (n = 33, history of depressions: 39.4%; previous psychological supervision: 33.3%). Furthermore, the analysis of the Big Five personality traits revealed remarkably elevated neuroticism scores in the iA collective. CONCLUSION: The current study demonstrates an increased rate of positive pre-interventional psychiatric histories in the iA collective. Although those patients represent only a small subgroup, they still may play an important role concerning the overall outcome after iA treatment. Early detection and psychological support in this subgroup might help to improve the overall outcome. Further studies are needed to evaluate the influence of this new aspect on the multifactorial etiology of unfavorable psychiatric outcome after treatment of iA.

De novo aneurysm of the anterior communicating artery presenting with subarachnoid hemorrhage 7 years after initial cryptogenic subarachnoid hemorrhage: a case report and review of the literature.

Spontaneous subarachnoid hemorrhage (SAH) is usually caused by a ruptured cerebral aneurysm. Despite the use of initial four-vessel cerebral digital subtraction angiography (DSA), 15 % of all cases remain idiopathic. According to the initial computed tomographic scan, the spontaneous SAH can be divided into a perimesencephalic group associated with a benign nature and a nonperimesencephalic group with a similar clinical course as aneurysmal SAH. We present a case of a 49-year-old man with a de novo aneurysm formation of the anterior communicating artery with SAH 7 years after initial cryptogenic nonperimesencephalic SAH. This observation suggests that in some cases, long-term angiographic studies might be justified.

Dopamine treatment of brain-dead Fisher rats improves renal histology but not early renal function in Lewis recipients after prolonged static cold storage.

BACKGROUND: Brain death (BD) and cold preservation are major risk factors for an unfavorable transplantation outcome. Although donor dopamine treatment in brain-dead rats improves renal function and histology in allogeneic recipients, it remains to be assessed if this also holds true for the combinations of BD and prolonged static cold preservation. METHODS: BD was induced in F344 donor rats, which were subsequently treated with NaCl 1 mL/h (BD, n = 11), NaCl/hydroxy ethyl starch (BD-norm, n = 10), or 10 µg/min/kg dopamine (BD-dopa, n = 10). Renal grafts were harvested 4 h after BD and transplanted into bilateral nephrectomized Lewis recipients 6 h after cold preservation in University of Wisconsin solution. Renal function was evaluated by use of serum creatinine and urea concentrations at days 0, 1, 3, 5, and 10. Ten days after transplantation, recipients were killed and the renal allografts were processed for light microscopy and immune histology. RESULTS: Serum urea concentrations at days 5 and 10 were significantly lower in recipients that received a renal graft from dopamine-treated rats; for serum creatinine, only a trend was observed at day 10. Immune histology revealed a lower degree of ED1-positive cells in the donor dopamine-treated group. Under light microscopy, Banff classification revealed significantly less intimal arteritis in these grafts (P < .05). CONCLUSIONS: Although donor dopamine treatment clearly improves renal histology in this model, the beneficial effect on early renal function was marginal. It remains to be assessed if donor dopamine treatment has a beneficial effect on renal function in long-term follow-up.

Robust detection of sleep apnea from Holter ECGs. Joint assessment of modulations in QRS amplitude and respiratory myogram interference.

INTRODUCTION: This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Studying Cardiovascular and Respiratory Systems". OBJECTIVES: Detect presence of sleep-related breathing disorders (SRBD) in epochs of 1 min by signal analysis of Holter ECG recordings. METHODS: In 121 patients, 140 synchronized polysomnograms (PSGs) and 8-channel Holter ECGs were recorded. The only excluded condition was persistent arrhythmias. Respiratory events as scored from the PSGs were mapped to a 1 min grid and served as reference for ECG-based detection. Moreover, 69/70 recordings of the Physionet Sleep Apnea ECG Database (PADB) were included. We performed receiver operating characteristics analysis of a single, novel time-domain feature, the joint local similarity index (jLSI). Based on cross-correlation, the jLSI quantifies the time-locked occurrence of characteristic low-frequency (LF) modulations in ECG respiratory myogram interference (RMI), QRS amplitude (QRSA) and heart rate. RESULTS: Joint oscillations in QRSA, RMI and the envelope of RMI identified positive epochs with a sensitivity of 0.855 (PADB: 0.873) and a specificity of 0.86 (PADB: 0.88). Inclusion of heart rate did not improve detection accuracy. CONCLUSIONS: Joint occurrence of LF-modulations in QRSA and RMI is a characteristic feature of SRBD that is robustly quantified by the jLSI and permits reliable and reproducible detection of sleep apnea in very heterogeneous settings.

Using an audience response system to improve learning success in practical skills training courses in dental studies - a randomised, controlled cross-over study.

INTRODUCTION: The aim of this study was to examine whether the use of an audience response system (ARS) in a high-quality study design, in a course in pre-clinical dentistry leads to an improvement in cognitive and psycho-motor performance. MATERIALS AND METHODS: As part of the Phantom Course I, a randomised, controlled study in cross-over design with 63 students was conducted over 4 weeks. The intervention was carried out by means of an ARS (TurningPoint(®) ), while a verbal question-and-answer session was conducted within the control group. Differences in learning success were determined via a formative multiple-choice (MC) test (cognitive) and a summative practical test (psycho-motor). RESULTS: Both groups achieved significantly better results in the MC tests with the use of the intervention, when compared with the control group (group A 11.6 vs. 9.5 and group B 13.7 vs. 12.1, maximum 16 points). A further analysis of the results showed that the overall effect was induced primarily by a marked improvement in below-average students. The practical tests showed no clear effect. Despite the careful selection and set-up of the conditions for the study in the regular course of the semester, a cohort effect emerged. This was due to varying degrees of performance between the two groups, because no adequate performance parameters were available, which could have been taken into account for the stratified randomisation. CONCLUSIONS: The results indicate that the use of the ARS leads to better results in cognitive performance, especially where independent learning is required and should be encouraged. Weaker students in particular seem to benefit.

Value of diffusion-weighted imaging in central pontine and extrapontine myelinolysis.

INTRODUCTION: Central pontine myelinolysis (CPM) and extrapontine myelinolysis (EPM) are rare neurological disorders characterized by demyelination in and/or outside the pons. Whether diffusion-weighted imaging (DWI) might facilitate an earlier diagnosis has not yet been studied systematically. METHODS: We describe demographics, clinical presentation, and early magnetic resonance imaging (MRI) findings with special emphasis on the relevance for diagnosis of CPM and/or EPM in eight patients. RESULTS: Of the analysed eight patients (aged 37-70 years; two men, six women), CPM was diagnosed in three, EPM in one, and a combination of CPM and EPM in four patients. Aetiology was rapid correction of sodium in two patients; a combination of hyponatremia, alcoholism and alcohol withdrawal in five patients and unclear in one patient. Seven patients suffered from chronic alcoholism and four from malnutrition. Demyelinating lesions were found in the pons, thalamus, caudate nucleus, putamen and midbrain. While the lesions could be clearly delineated on T2- and T1-weighted images, DWI demonstrated a strong signal in only six patients. Furthermore, DWI demonstrated lesions only to some extent in two patients and was completely negative in two patients on initial MRI. In none of the patients did the demonstration of hyperintense lesions on DWI precede detection on conventional MRI sequences. Apparent diffusion coefficient (ADC) values were heterogenous with a decrease in two cases and an increase in the remainder. CONCLUSIONS: We conclude that early DWI changes are a common finding in CPM/EPM but do not regularly precede tissue changes detectable on conventional MRI sequences. Heterogenous ADC values possibly represent different stages of disease.

[Dyspnea, fatigue and subpulmonary mass]. / Dyspnoe, Fatigue und subpulmonale Raumforderung.

A 52-year-old man was referred for progressive dyspnea and fatigue. The medical history was unremarkable and there were no signs of late infections or previous tumorous diseases. Physical examination revealed diminished breath sounds and a dull tone over the right lower side. Routine blood tests, arterial blood gas and body plethysmography were all within normal ranges. Chest X-ray and thorax computed tomography (CT) showed the presence of a homogeneous subpulmonary mass with a diameter of 10 cm which had a water-like density of approximately 1 Hounsfield unit (HU). The presence of an extraordinary large pericardial cyst compromising the right lower lobe and therefore causing dyspnea was confirmed by video-assisted thoracoscopic surgery (VATS). Pericardial cysts are rare congenital mediastinal masses. They are usually asymptomatic and are usually found incidentally during routine chest X-ray, CT, magnetic resonance imaging (MRI) or echocardiography. Most pericardial cysts are situated at the right cardiophrenic angle. When reaching a relevant size they can cause symptoms such as dyspnea, coughing, chest pain and fatigue. The imaging studies most useful for diagnosis are CT, MRI and echocardiography. Differential diagnoses are diaphragmatic hernia, trapped pleural effusion or other pleural or mediastinal tumors.

Recent trends in incidence and mortality of oral and pharyngeal cancer in Schleswig-Holstein in Northern Germany.

OBJECTIVE: Oral and pharyngeal cancer is still a serious public health problem with more than 10,000 new cases every year in Germany, more than 4,000 patients die of this tumour each year. Aim of the project was a detailed analysis on incidence and mortality rates by age, gender and tumour sites in Northern Germany. METHODS: The data on incidence and mortality rates from the population-based Cancer Registry of Schleswig-Holstein in Northern Germany were evaluated by age, gender and tumour sites from 2000 to 2006. RESULTS: Some 3,127 new cases of oral and pharyngeal cancer (72% men, 28% women) were registered. About half of all cases were aged 60-79 years. The incidence trends for 40-59 years described a slight decrease. Trends for pharyngeal cancer showed the highest incidence rates for both genders in those aged 60-79. This detailed analysis with subgroups showed interesting differences and revealed considerable variations, especially compared to the increasing trends in several European countries. CONCLUSIONS: These population-based data of Schleswig-Holstein showed interesting differences in the trends for incidence and mortality rates for age groups and tumour sites within the state and compared to the national German data and revealed noticeable different trends compared to several European countries. This population-based information informs effective cancer control.

[Diagnostic value of transthoracic ultrasound compared to chest radiography in the detection of a post-interventional pneumothorax]. / Diagnostische Wertigkeit der transthorakalen Sonografie vergleichend zur Thoraxübersicht beim Nachweis eines postinterventionellen Pneumothorax.

PURPOSE: Chest radiography is standard for the diagnosis of a pneumothorax. However, also ultrasound of the chest has considerable value in the detection of a pneumothorax. A typical sonographic feature is the lack of the lung gliding sign. Aim of our trial was to evaluate the significance of ultrasound of the chest in the diagnosis of a pneumothorax supplemented by using power colour Doppler imaging. PATIENTS AND METHODS: Following transbronchial biopsy, patients received transthoracic ultrasound of the chest for evaluation of a pneumothorax. Immediately afterwards, a chest radiograph was performed and results were compared. RESULTS: 1023 patients (321 female, 702 male, median age 47 years) were examined. In 30 patients (2.9%) chest radiograph revealed a pneumothorax, while in ultrasound of the chest a pneumothorax was diagnosed in 36 of the cases. Defining chest radiography as gold standard, ultrasound of the chest had a sensitivity of 100%, a specificity of 83% and an accuracy of 99%. CONCLUSION: Transthoracic ultrasound of the chest is a highly sensitive and specific diagnostic tool in the diagnosis of a pneumothorax. In comparison to chest radiography, it is better available and prevents administration of ionizing radiation. However, a disadvantage of ultrasound is the lack of quantification of a pneumothorax and the assessment of the indication for chest tube drainage.

[Dyspnea in a 45-year-old man with liver cirrhosis]. / Dyspnoe bei einem 45-jährigen Patienten mit Leberzirrhose.

HISTORY AND ADMISSION FINDINGS: During evaluation for a liver transplantation in a 45-year-old man with alcoholic liver he complained of exertional dyspnea. He had grade 3 chronic obstructive pulmonary disease (COPD) after nicotine abuse of 50 pack-years. One and a half years earlier the patient had been treated for tuberculosis. INVESTIGATIONS: The diagnostic procedures showed a respiratory insufficiency with a PO(2) of 52 mm Hg. Notable was a missing improvement of oxygenation after the supply of 100 % oxygen. Lung perfusion scintigraphy showed a shunt of about 14 %, a contrast-medium echocardiography demonstrating a right-to-left shunt. These findings indicated that the patient had a hepatopulmonary syndrome. TREATMENT AND COURSE: The only causal therapy of a hepatopulmonary syndrome was a liver transplantation. However, the tuberculosis diagnosed one and a half years earlier had not been treated adequately, so that an antituberculotic therapy was essential before starting an immunosuppression. Therefore the only option of treatment was to continue the long-term oxygen therapy. As a matter of differential diagnosis and because of the intrapulmonary shunt, a pulmonary venous disconnection for a shunt caused by tuberculous cavities or by the COPD had to be taken into account. CONCLUSION: Treating patients with advanced liver cirrhosis and dyspnea a hepatopulmonary syndrome must be taken into consideration. Typically there will be found a right-left-shunt. In addition, coexistent comorbidities as a reason for dyspnea have to be excluded.

Classification of sleep stages using multi-wavelet time frequency entropy and LDA.

BACKGROUND: The process of automatic sleep stage scoring consists of two major parts: feature extraction and classification. Features are normally extracted from the polysomnographic recordings, mainly electroencephalograph (EEG) signals. The EEG is considered a non-stationary signal which increases the complexity of the detection of different waves in it. OBJECTIVES: This work presents a new technique for automatic sleep stage scoring based on employing continuous wavelet transform (CWT) and linear discriminant analysis (LDA) using different mother wavelets to detect different waves embedded in the EEG signal. METHODS: The use of different mother wavelets increases the ability to detect waves in the EEG signal. The extracted features were formed based on CWT time frequency entropy using three mother wavelets, and the classification was performed using the linear discriminant analysis. Thirty-two data sets from the MIT-BIH database were used to evaluate the performance of the proposed method. RESULTS: Features of a single EEG signal were extracted successfully based on the time frequency entropy using the continuous wavelet transform with three mother wavelets. The proposed method has shown to outperform the classification based on a CWT using a single mother wavelet. The accuracy was found to be 0.84, while the kappa coefficient was 0.78. CONCLUSIONS: This work has shown that wavelet time frequency entropy provides a powerful tool for feature extraction for the non-stationary EEG signal; the accuracy of the classification procedure improved when using multiple wavelets compared to the use of single wavelet time frequency entropy.