Biomedical subjects
Publications and source records attributed to P Huber.
Ten patients with suspected abnormalities or thrombosis of the superior sagittal sinus were studied by high resolution computed tomography using a thin slice technique after bolus injection. In all patients good visualization of the sinus pathology could be achieved, which correlated exactly with the findings in the 7 angiographically controlled cases.
A case of a 48 year old women is reported in whom a haemangiopericytic meningioma involving the middle third of the superior sagittal sinus was radically excised. The sinus was replaced by a saphenous vein graft and the Rolandic veins were reinserted. During clamping of the sinus the patient was heparinized and hypothermia, hypotension and barbiturates were used to prevent swelling of the brain. The postoperative course was uncomplicated and patency of the graft was demonstrated 2 weeks after the operation by Doppler sonography performed through a midline burr hole. The technical details of the operation and the pertinent physiology of cerebral venous flow are discussed.
A retrospective analysis of 45 patients with intra- and extracanalicular lumbar disc herniations (ICDH, ECDH), collected over a 3 year period, is presented. When an intra- or extracanalicular DH was suspected, 1.5 mm axial cuts were made with a GE9800 from the cranial pedicle through the intervertebral canal to the pedicle of the lower vertebral body. Constructions were then made in coronal and paraxial planes to identify the pathology and its relation to the nerve root. 47% of all ICDH and ECDH were found at the level L4/5, 24% each at the levels L3/4 and L5/S1 respectively and 4% at the level L2/3. In 78% of our patients, the disc fragment was extruded and found well above the level of the disc space, in 22% at the level of the disc space. The coronal reformated views were in general better for demonstrating the course of the compressed nerve root at the levels L2/3-L4/5, while at L5/S1 the paraxial reformated view may yield better images. The distance from the midline of the spinal canal to the medial and lateral edge of the ECDH averages 16.4 +/- 3.4 and 33.3 +/- 3.6 mm and in some cases the lateral edge was found 39-44 mm from the midline. Pitfalls in the diagnosis of ECDH may be caused by scar tissue, sometimes by an upwardly displaced nerve root or ganglion and, very rarely, by a neurinoma. Pitfalls in therapy, i.g. false negative intraspinal exploration in cases of intra- or extracanalicular disc herniations or exploration of the wrong intervertebral canal, may result due to insufficient neuroradiological analysis or from insufficient consideration of the anatomical situation by the neurosurgeon.
We report on 3 patients with meningoradiculoneuritis (MRN) due to Lyme-borreliosis (LB), which presented clinically as vertebral disc herniation. In 2 cases the underlying infection was discovered only after unsuccessful neurosurgical treatment. In the differential diagnosis between MRN and disc herniation the following criteria are suggestive of MRN and should raise suspicion of a non-discogenic aetiology: History of tick bite or erythema chronicum migrans, fever or general malaise, mono- or oligoradiculopathy with absent or insignificant lumbar pain and complaints of a burning character of the radiating pain. In suspicious cases we recommend blood investigations including antibody determination against borrelia burgdorferi and CSF investigations including cell count and cytology, protein and glucose determination, nephelometry and isoelectric focusing to exclude MRN and other conditions that may mimic disc herniation.
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Intraorbital and periorbital structures can be examined very accurately by computerized tomography and magnetic resonance imaging. On the basis of the data acquired during axial (or coronal) CT examination, reformations in any given plane are possible and the relations between a space-occupying lesion and intraorbital structures such as the globe, optic nerve, or extraocular muscles can be clearly demonstrated, as shown by several examples. The main advantage of CT over MRI is the shorter examination time. Hence CT is currently to be preferred for initial examinations.
From January 1981 to June 1986 116 patients with anticoagulation-related intracranial haemorrhage were referred to hospital. Seventy six of these haemorrhages were extracerebral, 69 were in the subdural and seven in the subarachnoid space. No epidural haemorrhages were identified. Compared with non-anticoagulation-related haematomas, the risk of haemorrhage was calculated to be increased fourfold in men and thirteenfold in women. An acute subdural haematoma, mostly due to contusion, was more frequently accompanied by an additional intracerebral haematoma than a chronic subdural haematoma. Trauma was a more important factor in acute subdural haematomas than in chronic. Almost half of the patients (48%) had a history of hypertension, more than a third (35%) had heart disease and about one fifth (18%) were diabetic. Headache was the most frequent initial symptom. Later decreased level of consciousness and focal neurological signs exceeded the frequency of headache. Three patients with subarachnoid haemorrhage and nine patients with acute subdural haematomas died, while those with chronic subdural haematomas all survived and had at the most mild, non-disabling sequelae. Myocardial infarction (22%), pulmonary embolism (20%), and arterial disease (20%) were the most frequent reasons for anticoagulant treatment. Critical review based on established criteria for anticoagulation treatment suggests there was no medical reason to treat a third of these patients. The single most useful measure that could be taken to reduce the risk of anticoagulation-induced intracranial haemorrhage would be to identify patients who are being unnecessarily treated and to discontinue anticoagulants.
Accurate assessment of blood flow velocities and diameter measurements in veins are possible by duplex-scanning. We used the technique for the measurement of venous blood flow velocity under different physiological conditions and after the administration of dihydroergotamine (DHE). In 15 healthy subjects (mean age 30.4 years) diameter, peak and mean flow velocity of the popliteal vein were measured in lying and standing position before and after intravenous administration of 1 mg DHE. Mean diameter of the popliteal vein was 0.62 +/- 0.06 cm in the recumbent position and was significantly larger in the erect position (0.84 +/- 0.1 cm). Peak flow velocity was 17.4 +/- 4.9 cm/s, mean flow velocity 6.0 +/- 2.4 cm/s in the recumbent subjects. There was a significant decrease (p less than 0.001) of both velocity parameters in erect position. DHE causes a significant (p less than 0.001) decrease in diameter of the popliteal vein (14.5%) at rest and the enlargement was less (p less than 0.001) marked when the subject got up. After DHE administration a statistically insignificant increase in peak and mean flow velocity at rest and a significant (p less than 0.001) increase in mean flow velocity in the upright position was observed. In addition DHE induced a more pulsatile venous flow. This finding may be of importance in the prevention of deep vein thrombosis. Our results show that duplex-scanning allows precise assessment of venous blood flow velocities under different conditions. The technique is useful for direct measurement of the efficacy of vein active drugs.
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Deep vein thrombosis of the upper extremity is rare. While its pathogenesis is not always evident, it often occurs in connection with tumors, thoracic outlet syndrome or intravenous catheter therapy. Acute thrombosis of the subclavian vein usually is a clinical diagnosis, but in doubtful cases diagnostic tests such as Doppler ultrasound and/or plethysmography may be useful. If necessary, verification of subclavian vein thrombosis can be done by phlebography. Considering the incidence of thromboembolic complications such as pulmonary embolism, anticoagulation is indicated in all cases of acute thrombosis. Under standard conservative treatment residual symptoms following the venous occlusion are few and the prognosis is favorable. Therefore, invasive treatment such as thrombectomy or thrombolysis should be considered only in special cases.
The transcranial Doppler sonographic findings of 61 patients with middle cerebral artery (MCA) disease were compared with those of 535 controls. According to computed tomographic, angiographic, and/or autopsy findings, the patients were classified as having MCA occlusive lesions in the central (sphenoidal) part or in peripheral branches or MCA stenosis. With MCA lesions, the MCA flow velocity (FV) was reduced. At the same time the anterior cerebral artery FV increased because of collateral flow over leptomeningeal anastomoses. Central MCA lesions showed less marked changes than did peripheral lesions. In MCA stenosis a steep rise of MCA FV appeared inside the stenotic segment. If there was a high-grade stenosis or occlusion of the internal carotid artery, a collateral circulation over the anterior part of the circle of Willis was seen in addition to the changes caused by the MCA disease. From these hemodynamic changes, transcranial Doppler sonographic diagnostic criteria for MCA occlusive and stenotic lesions were established.
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A 7,022 bp BamHI-EcoRI fragment, located in the inverted repeat of spinach chloroplast, has been sequenced. It contains a 2131 codon open reading frame (ORF) homologous to both tobacco ORFs 581 and 1708, and to Marchantia ORF 2136. Relative to the Marchantia chloroplast genome, spinach ORF 2131 is located at the end of a large inversion; the other end point is close to trnL, the position of which is the same in Marchantia, tobacco and spinach. In Marchantia, two 8 bp direct repeats flanking two 10 bp indirect repeats are present near the end points of the inversion. These repeats may result from a transposon-mediated insertion which would have facilitated the subsequent inversion. From a comparison of the gene organization of the spinach, tobacco, and Marchantia genomes in this region, we propose a step-wise process to explain the expansion of the inverted repeat from a Marchantia-like genome to the spinach/tobacco genome.
In human brain tumours the extension of peritumoural brain oedema may vary considerably. 37 brain tumours of various pathology and 2 abscesses were examined to identify the factors and mechanisms responsible for the oedema spreading. Peritumoural oedema profiles were determined towards the white matter and ventricle by measuring the CT-numbers of consecutive tissue blocks of 3.0-3.6 mm from the tumour to the normal white matter or the ventricle. It was found that neither the size of the tumour nor the histology has a close relationship to the amount of peritumoural oedema. The distance of oedema spreading rather is determined by the amount of fluid accumulation in the white matter immediately bordering the tumour. This relationship corresponds to a semilogarithmic function and represents the relation between the tumour-adjacent accumulation of extracellular fluid volume and the distance of extracellular fluid movement. The analysis of this relation leads to the suggestion that pressure gradients and bulk flow are involved in the development of human peritumoural oedema.
A total of 153 consecutive patients with proven aneurysmal subarachnoid hemorrhages (SAHs) admitted immediately after diagnosis regardless of clinical condition were managed according to the same protocol. The initial evaluation included computed tomography (CT), transcranial Doppler ultrasound (TCD), angiography-CT, and/or angiography. Intravenous nimodipine (2 mg/hour) was started after confirmation of the diagnosis. The timing of operation was determined individually according to age, clinical course, and CT and TCD findings. Twenty-one Grade V patients treated with intensive care and ventriculostomy died or did not improve within 24 hours after SAH. Three patients with life-threatening intracerebral hematomas underwent emergency operation. Operation was early in 55 good risk patients and late in 57 patients because of poor initial grade, late admission, or logistic reasons. Seventeen patients had no operation because of old age, persistent poor clinical condition, medical complication, or lethal rebleeding before operation. In the total series, 90 patients (59%) made a full recovery, the overall morbidity rate was 14% (21 of 153 cases), and the mortality rate was 27% (42 of 153). Postoperative mortality including emergency evacuation of hematomas was 7.8% and mortality after elective operation was 6.2%. The causes of disability and death were the initial effect of the hemorrhage in 25 patients (16.3%), rebleeding in 15 (9.8%), delayed cerebral infarction in 8 (5.2%), surgical complications in 7 (4.5%), hydrocephalus in 4 (2.6%), and medical complications in 4 (2.6%).
The popliteal aneurysm as the cause of an acute arterial obliteration pattern is sometimes misinterpreted or overlooked. However, if a femoropopliteal aneurysm is confirmed, the therapeutic approach is substantially different. The article reports on the results of the radiological diagnosis of 17 popliteal aneurysms and the diagnostic relevance of the applied imaging processes is discussed. Real-time sonography and angiography complement each other in their findings and prove to be an indispensable part of preoperative diagnosis.
Neuroradiology, originally developed through invasive techniques arising out of cooperation between radiology and neurosurgery, has today become a specialty which, thanks to its new non-invasive methods, can provide much information about diseases of the nervous system. The diagnosis of affections of the brain parenchyma in vivo by computed tomography or magnetic resonance demands intensive cooperation between all the specialties in the field of neurosciences, especially neurobiochemistry. Beyond its diagnostic applications, interventional neuroradiology has opened up promising therapeutic perspectives.