Movement Artefacts and MR BOLD Signal Increase During Different Paradigms for Mapping the Sensorimotor Cortex

Summary. Summary.   Background: The authors evaluated the impact of motion artefacts on presurgical mapping of the sensorimotor cortex with functional magnetic resonance imaging (fMRI). Different mapping paradigms were compared with regard to the frequency of motion artefacts and the resulting signal increase.   Method: 94 surgical candidates with mass lesions near the central region were investigated using BOLD¹-contrast T2^* weighted multislice multi-echo EPI gradient echo sequences on a 1,5 T Philips Gyroscan. Three functional paradigms were performed: a) repetitive self-paced clenching of the hand to a fist (68 runs); b) repetitive finger-to-thumb opposition (46 runs); c) sensory stimulation by repetitive brushing of the palm (15 runs). Task-related haemodynamic changes were identified by statistical analysis with the Kolmogorov-Smirnov-test. MR signal increase in percent was calculated for each of the paradigms. Motion artefacts were rated on a scale from 1 to 3.   Findings: Severe motion artefacts occurred in 8 hand clenching runs and in 2 finger opposition runs. Artefacts were more pronounced in hand clenching than in finger opposition. There were no motion artefacts in any of the sensory stimulation runs. Concerning the percent MR signal change there was no significant difference between hand clenching and finger opposition (T-test: p>0,5) but a highly significant difference (p<0,0001) between both motor tasks and the sensory paradigm (hand clenching: 2.68±0.75; finger opposition: 2.76±0.79; sensory stimulation: 1.72±0.65).   Interpretation: Sensory stimulation causes by far less artefacts than motor paradigms but it also has to be considered less sensitive as it produces a smaller MR signal increase. Therefore in presurgical evaluation sensory stimulation should be kept in reserve for cases in whom motion artefacts are very likely to occur, i.e. patients with severe forms of paresis.     

Intramedullary hemangioblastomas: timing of surgery,microsurgical technique and follow-up in 23 patients

Hemangioblastomas are highly vascularised tumors of the central nervous system and account for 1.5–2.5% of all spinal cord tumors. Because of the rarity of these tumors, surgical experience is often limited and, therefore, treatment and indications for timing of surgery are discussed controversial. The authors reviewed their data of 23 consecutive patients with respect to timing of surgery, microsurgical technique, and follow-up. Clinical records of 23 consecutive patients with intramedullary hemangioblastomas who underwent first surgery in our department between 1990 and 2005 were reviewed. In three cases the tumors were localised at the craniocervical junction; four patients had a single tumor in the cervical spine, six patients multiple tumors in the cervical and thoracic spine, eight patients in the thoracic spine only, one patient in the conus region, and one patient had multiple tumors located in the thoracic and lumbar spine. In eight patients, a von-Hippel-Lindau disease (VHL) was associated. The neurological follow-up was evaluated according to the classification of McCormick. Operation was recommended to every symptomatic patient as early as possible. In asymptomatic patients with a sporadic tumor surgery was discussed for diagnostic purposes at any time. In VHL patients, surgery was recommended if tumor growth was observed on MRI in the next practicable time. All tumors were diagnosed by magnetic resonance imaging and in all cases but one a DSA was performed. All patients were treated microsurgically through a posterior approach. The tumors in the spinal cord were removed microsurgically through a partial hemilaminectomy (n = 1), a hemilaminectomy (n = 15), or laminectomy (n = 4) and at the craniocervical junction (n = 3) through a suboccipital craniotomy. During follow-up after 6 months, 18 patients remained neurologically stable (17 in McCormick grade I and 1 in McCormick grade II) and 5 patients recovered to a better status (3 from grade III to II, 2 from grade II to I). There was one complication with a CSF fistula and one recurrence/incomplete removal. Following the above-mentioned principles of microsurgical removal of intramedullary hemangioblastomas, operation is possible with a low procedure-related morbidity and can be recommended especially in VHL patients with progressive symptoms or tumor growth during follow-up. Patients without VHL most frequently require hemangioblastoma resection for diagnostic purposes and/or because symptoms prompted an imaging work-up that lead to the discovery of the tumor.     

捻针时真、假穴不同中枢激活效应的脑功能MRI

目的利用功能磁共振(fMRI)观察捻针针刺方法对大脑的作用。方法用盲法随机分别针刺13例正常人左侧太冲、丘墟和假穴，手法采用捻针和不捻针，利用1．5TMR仪行全脑功能成像，用SPM99b分析图像。结果发现只在真穴捻针针刺时有更强的激活效应，有显著性意义的Brodmann激活区域为：针刺太冲穴激活了左右顶叶BA40区，右额叶BA47和10区，右丘脑，左小脑；针刺丘墟穴激活了左右顶叶BA40区，右顶叶BA2区，左额叶BA9、10、44区，左岛叶BA13区，左颞叶BA22区，右颞叶BA42区，右壳核，左小脑。两真穴激活部位部分相同，部分不同。在假穴捻针对不捻针的研究中，未见到有显著性意义的激活区。结论真穴捻针时可能对皮层神经活动有较特异的作用，而假穴未观察到此种现象，推测这可能是针刺治疗作用的机制之一。     

Mitochondrial DNA sequences in prehistoric human remains from the Alps

The spread of agriculture that started in the Near East about 10 000 years ago caused a dramatic change in the European archaeological record. It is still unclear if that change was caused mostly by movement of people or by cultural transformations. In particular, there is disagreement on what proportion of the current European gene pool is derived either from the pre-agricultural, paleolithic and mesolithic people, or from neolithic farmers immigrating from the south-east. To begin to characterise the mtDNA gene pool of prehistoric Europe we examined five human remains from the Eastern Italian Alps, dated between 14 000 and 3000 years ago. Three of them yielded sufficient amount of mtDNA for analysis. DNA extracts were prepared in two independent laboratories, and PCR products from the first hypervariable segment of the mtDNA control region were cloned and sequenced. Together with the 5200 year old 'ice man', these DNA sequences show that European mtDNA diversity was already high at the beginning of the neolithic period. All the neolithic sequences have been observed in contemporary Europeans, suggesting genealogical continuity between the neolithic and present-day European mtDNA gene pool. The mtDNA sequence from a 14 000 year-old specimen was not observed in any contemporary Europeans, raising the possibility of a lack of continuity between the mesolithic and present-day European gene pools.     

Fulminante Mycoplasma-pneumoniae-assoziierte Meningoenzephalitis des Erwachsenen

Mycoplasma pneumoniae (M. pn.) commonly causes respiratory tract infections in humans. In a certain percentage of cases it may also be associated with various peripheral and central nervous system manifestations. We report a case of a 38-year-old previously healthy man who presented with hemiplegia and somnolence after he had suffered from a febrile respiratory infection 10 days earlier. Clinical features and laboratory investigations supported the diagnosis of an acute M. pneumoniae-associated meningoencephalitis. He was treated by an aggressive antibiotic and immunomodulatory regimen over the course of several weeks in the neurocritical care unit. Decompressive hemicraniectomy was performed due to life-threatening raised intracranial pressure. However, the patient recovered almost completely and presented with a mild neurological deficit after 3 months. Based on this case we give a review of the literature and discuss potential pathomechanisms and diagnostic approaches.     

Vergleichende Untersuchungen über den Gehalt des menschlichen Serums an Gesamtlipiden,Lipokonjuenen und -peroxyden

Ohne Zusammenfassung     

Alternative shift models and the quality of patient care

On 1 January 1996, the German Arbeitszeitgesetz (working-time regulation) came into effect for hospital physicians. It states that working hours must not exceed 8 h per day, even for physician in hospitals. As a consequence, the prevalent two-shift model is legally inadmissible. The intention of this law is to protect the physician and to create better conditions for the patients. However, a systematic evaluation of the postulated benefits is still lacking. AIM: The aim of our study was to analyze the influence of the length of daily working hours on the quality of patient care by measuring the outcome of patients in intensive care units (ICUs), comparing the two-shift model (2-SM)--two 12-h shifts--with the three-shift model (3-SM)--three 8-h shifts. MATERIALS AND METHODS: In a prospective multicenter study, we compared the outcome of patients in six ICUs (organized by surgeons) with different models of working hours. The health status of each patient and the course on ICU [described by hospital mortality, number of complications, readmission to the ICU, reinterventions, duration of the stay in an ICU and hospital, the course of the Acute Physiology and Chronic Health Evaluation (APACHE) II score] were uni- and multivariately analyzed. In addition, the technical and personnel resources of the ICUs and the hospitals were documented. RESULTS: Three hundred and forty seven patients (103 2-SM, 244 3-SM) were included. The epidemiological and the health status on admission to the ICU were comparable. Patients in the 3-SM stayed 1.6 days longer on ICU and 2.3 days longer in the hospital than the 2-SM patients. The frequency of complications, reinterventions, and readmissions to ICU was higher in the 3-SM. The median of the APACHE-II score decreased more for 2-SM than for 3-SM patients. This means a significantly quicker recovery of the patients in 2-SM (P < 0.05). The multivariate analysis with individual outcome measures as dependent variables revealed a significant positive effect of the 2-SM on the physicians' assessment of postoperative course, on the relative frequency of therapeutic procedures, and to a lesser extent on the duration of stay in the ICU.     

Effect of gender and highly active antiretroviral therapy on HIV-related pulmonary arterial hypertension: results of the HIV-HEART Study

Background

Idiopathic pulmonary arterial hypertension (PAH) is a rare disease. HIV‐infected patients exhibit a considerably higher rate of development of this condition compared to the general population.

Methods

This cross‐sectional study of 802 (83.4% male; age 44.3±10.3 years) HIV‐positive patients aimed to evaluate the male‐to‐female ratio in HIV‐related PAH and to elucidate whether PAH is more likely to occur in patients receiving highly active antiretroviral therapy (HAART) than in HIV‐treatment‐naïve patients. All patients were examined by Doppler echocardiography to estimate systolic pulmonary arterial pressure (sPAP). Manifest PAH was defined as sPAP >35 mmHg at rest in combination with symptoms of dyspnoea.

Results

A total of 38 (4.7%) patients were diagnosed with elevated sPAP >35 mmHg. Fourteen (1.7%; 11 male) of these patients presented with symptoms of dyspnoea, resulting in a male‐to‐female ratio of manifest HIV‐associated PAH of 1:1.4. Patients with symptoms of dyspnoea and sPAP>35 mmHg were more likely to receive HAART (13/14 patients).

Conclusions

In HIV patients, sPAP occurs more frequently than has been reported previously; the condition is possibly associated with HAART. Furthermore, HIV‐positive females exhibit a higher prevalence of HIV‐related PAH (HIV–PAH) than HIV‐positive males.