Expansion of spatial and host range of Puumala virus in Sweden: an increasing threat for humans?

Hantaviruses are globally distributed and cause severe human disease. Puumala hantavirus (PUUV) is the most common species in Northern Europe, and the only hantavirus confirmed to circulate in Sweden, restricted to the northern regions of the country. In this study, we aimed to further add to the natural ecology of PUUV in Sweden by investigating prevalence, and spatial and host species infection patterns. Specifically, we wanted to ascertain whether PUUV was present in the natural reservoir, the bank vole (Myodes glareolus) further south than Dalälven river, in south-central Sweden, and whether PUUV can be detected in other rodent species in addition to the natural reservoir. In total, 559 animals were collected at Grimsö (59°43'N; 15°28'E), Sala (59°55'N; 16°36'E) and Bogesund (59°24'N; 18°14'E) in south-central Sweden between May 2013 and November 2014. PUUV ELISA-reactive antibodies were found both in 2013 (22/295) and in 2014 (18/264), and nine samples were confirmed as PUUV-specific by focus reduction neutralization test. Most of the PUUV-specific samples were from the natural host, the bank vole, but also from other rodent hosts, indicating viral spill-over. Finally, we showed that PUUV is present in more highly populated central Sweden.

Spontaneous healing of intracranial aneurysms after subarachnoid hemorrhage. Case report.

A case of spontaneous intra-aneurysmal thrombosis, verified angiographically, is reported in a patient with subarachnoid hemorrhage and without surgical intervention. The frequency of such an occurence and the factors involved are reviewed and discussed.

The value of repeat pan-angiography in cases of unexplained subarachnoid hemorrhage.

Four-vessel angiography was repeated in 56 patients with confirmed subarachnoid hemorrhage in whom the initial investigation was negative. Only one aneurysm was demonstrated. The results suggested that, with good technique, careful observation, and a complete four-vessel cerebral angiography, a false negative rate of less than 2% can be achieved. It is suggested that to repeat pan-angiography is seldom justified unless further bleeding episodes occur.

Intracranial malignant lymphoma. Report of 30 cases and review of the literature.

Although primary malignant lymphoma is a rare entity in the gamut of intracranial tumors, it is more frequently seen than the secondary intracranial spread of a primary extracranial lymphoma. In general, the occurrence of lymphomas seems to be provoked by immunosuppression, as with medication (predominantly after transplantation) or with immunodepressive disease such as acquired immunodeficiency syndrome (AIDS). The usual age of onset of this disease is 55 to 65 years; and the male:female patient distribution is roughly 2:1. Characteristically, computerized tomography (CT) scans of lymphomas show a mass which is often large with regular contours, moderate mass effect, and hyper- or isodensity with marked and often homogeneous enhancement. In the series of 30 patients reported, the locations of lesions, in order of decreasing frequency, were the frontocallosal and temporal regions, the basal ganglia, and the cerebellum. Multiple lesions were present in 15% of these cases (20% to 40% in the literature). The following features should raise the suspicion of intracranial lymphoma: mirror lesions of the basal ganglia, bilateral subependymal infiltration, and leptomeningeal involvement contiguous with an intracerebral mass. According to the literature, the angiographic finding typical of lymphoma is an avascular tumor. A blush or vascular encasement of the mass seems to be rare, and the present series was in accordance with other reports in this respect. Differential diagnostic consideration should include meningioma, glioblastoma, metastatic disease, and focal infectious lesions such as toxoplasmosis or multifocal progressive leukoencephalitis, particularly in immunodepressed subjects. Diagnosing lymphoma from CT scans offers the alternative of substituting stereotaxic biopsy and neuropathological diagnosis for the more aggressive open surgical approach, since radiation therapy and possibly chemotherapy usually prove to be the treatment of choice.

Complications of intraarterial digital subtraction angiography in patients investigated for cerebral vascular disease.

395 patients (236 males, mean age 55.6 years: 159 females, mean age 52.2 years) with suspected transient ischaemic attacks or previous strokes underwent intraarterial digital subtraction angiography (IADSA) over a 3-year period ending in March 1991. All procedures were performed via the femoral approach and the majority consisted of arch studies followed by selective catheterization. 253 (64.1%) of the patients had extracranial vascular disease confirmed at angiography. A retrospective analysis of the patients' records was made to extract all possible complications. Complications were defined as any untoward symptoms or signs occurring within 48 h and which could have been related to the angiogram. Neurological complications occurred in 15 (3.89%) patients. 10 (2.5%) patients had transient complications which resolved completely within 24 h. In three (0.8%) patients the neurological deficit was reversible, recovering fully within 6 days. Two (0.52%) patients were left with residual disability from stroke at 10 days. The permanent neurological complication rate is in the lower range of the rates recorded in previous conventional angiographic studies. We conclude that IADSA is a relatively safe and reliable form of investigation in patients with suspected cerebral vascular disease.

Development of feeding selectivity and consistency in food choice over 5 years in fallow deer.

In order to better understand the development and maintenance of feeding selectivity, several feeding experiments were performed with fallow deer (Dama dama L.). In experiments performed when the fawns were between ten and 27 days old, it was found that all fawns showed preferences for sucrose but aversions towards tannic acid and ascorbic acid. However, differences in selectivity towards tannic acid were present already before the fawns became functional ruminants and these individual differences lasted 5 years. Moreover, individuals that ingested overall less tannic acid, searched more thoroughly between food sources. When the foraging behaviour was compared with age (11-41 days old and 65-97 days old), it was found that the time a fawn spent eating, increased with age, and the time spent on exploration, smelling and tasting plants decreased with age. Furthermore, the fawns increased their intake of grass and herbs, while the intake of soil and dead plant material decreased with age.

Contrast enhancement of cranial lesions in computed tomography.

The time course of enhancement in apparently normal brain tissue, edema and focal lesions during 30 to 60 min after intravenous injection of vascular contrast medium was evaluated in a series of 41 patients with different intracranial lesions. The attenuation of apparently normal unenhanced brain tissue varied with the level of the scan, mainly an effect of beam hardening. Different types of enhancement response are discussed in terms of a 3-compartment model. The differential diagnostic potential of contrast enhancement in the early phase needs further evaluation using instruments with short scanning time, while the late phase of enhancement must be recorded with the use of a reliable head fixation to provide reproducibility of repeat measurements.

Prognostic significance of cerebral computed tomography results in supratentorial infarction.

In 69 patients with supratentorial cerebral infarction findings at computed tomography (CT) were related to clinical state on admission and course of recovery. In patients with initial disability of slight to moderate degree CT did not provide prognostically useful information; in patients with severe symptoms at onset location of lesion to the internal capsule or the right parietal lobe and the presence of the mass effect, as single factors or in combination, were ominous CT indicators in terms of functional recovery.

Quantitative estimation of intracerebral and intraventricular hematoma by computer tomography.

A method to quantify the size of intracerebral hematoma by computer tomography was tested experimentally. The size of the lesion could be calculated with an error of +/- 3 to 9 per cent. By correlating the volume of the hematoma to the level consciousness in 62 patients, it was found that the volume which induced coma was rather specific, corresponding to about 6 to 7 per cent of the intracranial volume. This observation may lead to a reassessment of present therapeutic concepts.

Computer tomography in post-mortem examination of the brain and other specimens.

A technique is described for post-mortem examination of brain specimens employing computer tomography, for accurate comparison with in vivo scanning, including subsequent cutting of specimens in sections corresponding to tomographic layers measured. Potential application of this technique to diagnosis of mammary tumours is discussed.

Cerebral medullary venous malformations. Report of four cases and review of the literature.

Each type of cerebral vascular malformation has its own unique clinical, radiological and pathological features, and a different pattern of natural evolution. With greater awareness and advances in neuroimaging, there is increasing recognition of Cerebral Medullary Venous Malformations (MVM), angiographically characterised by an 'Umbrella' or 'Caput Medusae' appearance. The clinical and radiological features of four patients with angiographically demonstrable features of cerebral medullary venous malformations, seen in our departments are presented to illustrate the features of cerebral MVMs. Three patients have been managed conservatively and one has been treated with stereotactic radiosurgery. The literature on cerebral MVMs has been reviewed and presented in this paper. It appears that most are benign and even in those cases where there has been a haemorrhage the outcome seems to be much better than with arteriovenous malformations. The rationale behind radiosurgical treatment is discussed. Before embarking upon any form of interventional therapy the natural course of these lesions should be considered.

Confusion, myoclonus and speech arrest: epileptic manifestations after metrizamide myelography.

The importance of accurate diagnosis of epileptic manifestations, even if unusual, as complications of diagnostic metrizamide exploration of the CSF space is emphasized on the basis of 2 case histories.

Computer intravenous angiography.

Computer tomography could be useful in demonstrating lesions of intracranial vascular structures. Experimental methods aimed at achieving this are presented and clinical examples using intravenous angiography are given. The factors involved by the demonstration of intracranial vessels are discussed.

Diaphanography in breast carcinoma. Correlation with clinical examination, mammography, cytology and histology.

Histologically classified carcinoma was present in 110 breasts of 108 symptomatic women. The results of diaphanography (DPG) were correlated with those obtained by clinical examination (CE), mammography (M) and cytology (C). A tumour was palpable in 87 cases (79.1%). A false negative diagnosis was made in 17 cases (15.5%) using DPG, in 13 cases (11.8%) using M and in 15 cases (13.6%) using C, but in 12 of the latter cases (10.9%) the specimen was not representative. The validity of the findings using DPG and M was also analysed. The calculations were based on the results obtained from the present investigation and from a study of diaphanography in 163 cases of benign breast disorders. For DPG the sensitivity was 85 per cent, the specificity 91 per cent, the positive predictive value 86 per cent and the negative predictive value 90 per cent. For M the sensitivity was 86 per cent, the specificity 80 per cent, the positive predictive value 75 per cent and the negative predictive value 91 per cent. The specificity for diaphanography was significantly different from mammography (p less than 0.05). The use of both M and DPG reduced the number of false negatives from 11.8 per cent to 5.5 per cent. In conclusion, DPG has been demonstrated to be a useful adjunct to CE and M.

Computer tomography of the brain and spectrophotometry of the CSF in cerebral concussion and contusion.

Computer tomography (CT) and spectrophotometry of CSF were performed in 30 patients with the clinical diagnosis of cerebral concussion or contusion. The patients with concussion all had normal CT-findings. Spectrophotometry of CSF was sometimes positive for cerebral contusion with normal CT-findings, but the two methods were complementary so that the extent of the lesion was determined by CT and spectrophotometry of CSF indicated the cause.

Chromosome analysis and sister chromatid exchange in encephalo-trigeminal angiodysplasia.

A female, aged 32, with facial birthmarks and suffering migraine headaches and a slight hemiparesis was examined with isotope scanning, CT and angiography. She was found to have a massive, unilateral angiodysplasia, transforming the right cerebral hemisphere into an expanding vascular sponge-like structure. There was a family history of red facial birthmarks. The patient and her father were analysed cytogenetically by estimating the frequency of chromosome aberrations and sister chromatid exchanges (SCE). The frequency of gaps and breaks was normal compared to healthy controls, but the patient showed a significantly higher level of spontaneous SCE's. The patient and her father also had a higher than normal number of SCE's after addition of mitomycin C (MMC) to the blood culture. Numerical and structural chromosome deviations markedly exceeded normal in both, possibly representing a genetic imbalance in this syndrome.

Growth failure secondary to moyamoya syndrome.

We describe a boy who presented at the age of 7 years with short stature due to hypopituitarism. Six months after starting appropriate hormone replacement treatment at the age of 8 he suffered his first generalised convulsion. Further neuroradiological investigation led to the diagnosis of moyamoya syndrome.