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Biomedical subjects

A Thron

Publications and source records attributed to A Thron.

At least 109 records · Page 6Linked to original sources
PubMed1993

Large thoracocervical intraspinal neuroma: unusual clinical and neuroradiological findings.

The clinical and radiological findings of a giant cystic intraspinal cervical tumour are presented. Symptoms and signs suggesting a polyneuropathy were misleading. On myelography the tumour appeared as a solid mass, but its size was distinctly underestimated. MRI demonstrated the true extent (from C4 to T4) and the cystic structure of the tumour. The histo-pathological diagnosis was fibrillary neuroma (WHO grade I).

Aged↗
PubMed1993

The case of aphasia or neglect after striatocapsular infarction.

The occurrence of aphasia or neglect was related to anatomo-structural (CT/MRI), functional [regional cerebral blood flow (rCBF)] and pathogenetic features [duration of middle cerebral artery (MCA) occlusion and degree of cortical leptomeningeal anastomoses] in 57 cases (26 with and 31 without aphasia or neglect) with strictly subcortical infarcts of one defined type, i.e. striatocapsular infarcts. No distinct pattern of language disturbances was found. Aphasic syndromes did not differ in the amount of involvement of the putamen, pallidum, head of caudate nucleus and white matter. Patients with aphasia or neglect had larger infarcts than those without. However, there was no specific involvement of the basal ganglia, the internal capsule or the deep white matter in patients with aphasia or neglect. Patients with aphasia or neglect had a significantly longer duration of MCA occlusion and mostly poor leptomeningeal collaterals. The cortical rCBF was significantly decreased in the cortical MCA territory in the patients with aphasia or neglect only. The rCBF remained low at follow-up after 1 year and corresponded to focal cortical atrophy on MRI, although neglect had subsided completely in all patients and aphasia had improved considerably in almost 75% of the cases. Aphasia or neglect after striatocapsular infarcts are most likely due to selective neuronal loss of the cerebral cortex due to prolonged MCA occlusion and insufficient collateral blood flow. Individual differences in recovery from aphasia after striatocapsular infarction can be explained in terms of the number of surviving cortical neurons.

Adolescent↗
PubMed1993

[Clinical course of paraneoplastic limbic encephalitis].

A 49-year-old woman presented with increasing memory loss without dementia. The EEG showed slow activity over the temporal lobe. MRT revealed temporal areas of increased signal intensity without gadolinium enhancement. The diagnosis of limbic encephalitis was made after detection of a bronchial carcinoma. A MRT control examination after chemotherapy showed resolution of the abnormalities. This observation may indicate that chemotherapy has modified that part of the immunological system responsible for induction of limbic encephalitis.

Carcinoma, Bronchogenic↗
PubMed1992

Bilateral anterior cerebral artery territory infarction in the differential diagnosis of basilar artery occlusion.

Two patients with bilateral anterior cerebral artery (ACA) territory infarction are presented whose initial diagnosis was basilar artery occlusion. Both had tetraparesis; in one it was asymmetrical. Both had their eyes open and did not respond to command except that after a delay they followed with their eyes a smoothly moving object; this was the only sign of awareness. One patient had a clear vertical gaze palsy in the upward and downward direction unaccompanied by pupillary abnormalities. Computed tomography revealed fresh bilateral ACA infarction in both patients; occlusion in the hind brain circulation was excluded by angiography in one. Both patients suffered from atrial fibrillation, so cardiac embolism was the most likely cause of the stroke. We conclude that bilateral ACA territory infarction should be considered in the differential diagnosis of basilar artery occlusion, even if accompanied by vertical gaze palsy.

Aged↗
PubMed1992

Type and extent of hemispheric brain infarctions and clinical outcome in early and delayed middle cerebral artery recanalization.

We evaluated the influence of time of recanalization or degree of initial leptomeningeal collateral blood flow in cardioembolic or arterio-arterial middle cerebral artery (MCA) occlusion on infarct size and clinical outcome in a series of 34 consecutive acute stroke patients with main stem (N = 31) or major branch (N = 3) occlusions using CT, initial cerebral arteriography (N = 21), repetitive close-meshed transcranial Doppler ultrasonography, and a neurologic stroke scale. We treated 15 patients with tissue plasminogen activator intravenously within the first 6 hours. The type and size of infarction depended on the location of the occluding lesions within the MCA trunk. Proximal MCA occlusion always led to infarction involving the striatum and internal capsule. Sixty-five percent of patients showed recanalization of the occluded MCA within 1 week. Following MCA recanalization, hyperperfusion was present in 38 to 44% of cases. There was a marginally significant relation between size of infarction on CT and recanalization time within the first 24 hours. The more rapidly recanalization occurred, the smaller the size of the infarct. When recanalization time was greater than 8 hours, the lesions always extended to the cortex. An additional good leptomeningeal collateral blood flow significantly reduced the size of the infarct and improved clinical outcome after 17 days and after 10 months. Early recanalization of embolic MCA occlusions within up to 8 hours, in conjunction with good transcortical collateralization, has a favorable impact on infarct size and outcome and may constitute the therapeutic window of opportunity.

Aged↗
PubMed1992

[Diagnosis of complications of ventriculo-peritoneal and ventriculo-atrial shunts].

The value of imaging (cranial CT, cranial and abdominal sonography, plain film surveys) was examined retrospectively in 28 shunted children in whom 82 instances of suspected dysfunction arose. There were 23 obstructions, 12 dislocations, 1 disconnection, 6 infections, 3 overdrainages and 5 slit ventricle syndromes. Impaired absorption with ascites, a peritoneal liquor cyst and a seroma occurred in the peritoneal part of the shunt. Progressive dilatation of the ventricle system shown by CCT (89%) or ultrasound was the most sensitive sign of high-pressure hydrocephalus. Periventricular hypodensity and flattening of the gyri (15%) were found less often. An examination strategy in suspected shunt dysfunction is suggested on the basis of these findings.

Cerebrospinal Fluid Shunts↗
PubMed1991

[Vascular architecture of the skin in the postmortem microangiogram].

To demonstrate the detailed vascular architecture of the skin, barium sulphate suspension was injected into the arteries of nine amputated lower limbs. Sections of skin from the foot were fixed in formalin and embedded in paraffin and then examined by high resolution radiography. Subsequently histological sections were prepared and correlated with the micro-angiographic appearances. This technique provided demonstration of the detailed vascular structure of the skin with very little super imposition. The capillary loops in the papillae, the sub-papillary plexus, the glandular components (with the capillaries surrounding the sweat glands), the fine arteries and smallest veins in the cutis could be demonstrated over a prolonged course. Microangiographic and histologic sections were carried out in parallel. These eliminated artifacts and clarified the micro-angiographic appearances. The value of microangiography for demonstrating the vascularity of the skin under normal, pathological and experimental conditions is the subject of further studies.

Aged↗
PubMed1991

Microinfarction in classic migraine? A study with magnetic resonance imaging findings.

By means of magnetic resonance imaging we investigated a total of 45 patients suffering from classic migraine; 25 patients had been treated in our department for classic migraine over the past 2 years (group A), and 20 other patients investigated between 1976 and 1984 were reexamined for this study (group B). Thirty-two age- and roughly sex-matched healthy volunteers underwent magnetic resonance imaging and served as controls (group C). There was a trend for patients with classic migraine to have more subcortical patchy lesions on T2-weighted magnetic resonance imaging. In a comparison of our control subjects and patients with a history of greater than 20 attacks of classic migraine taken from groups A and B, this difference in number of lesions was significant (p = 0.02). The results suggest that patchy lesions in patients with classic migraine should be interpreted with particular caution before diagnosing a demyelinating disease since the lesions could be ischemic in origin.

Adult↗
PubMed1990

The large striatocapsular infarct. A clinical and pathophysiological entity.

We examined 29 patients with strictly subcortical large striatocapsular infarctions. Eight of them had aphasia or neglect. All patients underwent transcranial Doppler ultrasonography or selective carotid angiography, magnetic resonance imaging, and single photon emission tomography for assessment of cerebral blood flow, blood volume, and cerebral perfusion reserve. The signs were compatible with cortical territorial infarctions rather than lacunes. On both magnetic resonance imaging and computed tomographic scans, the lesions corresponded to the territories of the medial and lateral group of the lenticulostriate arteries, Heubner's artery, or the anterior choroidal artery. The infarctions were either due to cerebral embolization into the M1 segment of the middle cerebral artery or due to stenosis at the same site, ie, lesions that acutely and simultaneously occluded the orifices of the lenticulostriate or neighboring arteries. Persistent occlusion of the middle cerebral arteries and a decrease of cortical regional cerebral blood flow were only found in patients with aphasia or neglect. All patients without aphasia or neglect showed a rapid recanalization of the middle cerebral artery occlusion or a stenosis of the M1 segment and no cortical regional cerebral blood flow decrease. Large striatocapsular infarctions occur due to occlusive disease of the middle cerebral artery (large-vessel disease) and not due to a disseminated in situ occlusion of the long penetrating arteries (small-vessel disease), as in lacunes. Neuropsychological deficits can be explained by decreased cortical blood flow due to a persistent occlusive lesion of the middle cerebral artery.

Adult↗
PubMed1990

Intracranial arterial aneurysms in children. Clinical, neuroradiological and histological findings.

Of our five cases of intracranial arterial aneurysms in children, there were two typical saccular aneurysms and three with fusiform or large peripheral vascular anomalies. Angiographic and histological examinations pointed to an additional arteriovenous malformation in the area of the aneurysm in two cases, combined in a third case with a cutaneous hemangioma of the brow. Other characteristics were typical of aneurysms in children such as low frequency, male preponderance, and location at the internal carotid artery bifurcation. Large peripheral aneurysms are not unusual in childhood. However, neuroradiological and neuropathological criteria reveal that such 'aneurysms' are often part of a complex arteriovenous malformation as has been presumed by some authors.

Aneurysm↗
PubMed1990

Central spinal cord lesions in stenosis of the cervical canal.

34 patients suffering from cervical spondylotic myelopathy confirmed by myelography were examined by delayed CT 6-10 h after myelography. Twelve patients showed bilateral intramedullary collections of contrast medium, predominantly cranial to the stenosis. In these patients males predominated, the duration of clinical symptoms lasted longer although their age was lower. There was no correlation to the degree and the extension of the narrowing of the cervical spinal canal. Half of 20 patients undergoing consecutive decompressive surgery showed intramedullary contrast enhancement, and this was shown again by postoperative MRI in eight. The postoperative clinical and neurophysiological results revealed no change in the majority of patients, but three patients showing intramedullary contrast medium deteriorated in neurophysiological outcome, while only one of the patients in whom intramedullary contrast medium was not noticed got worse.

Adult↗
PubMed1990

Total surface of temporoparietal intrasylvian cortex: diverging left-right asymmetries.

Measurements of the total convoluted surface area of cortex buried in the temporoparietal transition of the Sylvian fissure were performed using "three-dimensional" magnetic resonance morphometry in 10 randomly selected human cadaver brains. The measurements comprised the planum temporale, which covers the superior temporal gyrus posterior to Heschl's first transverse gyrus, and the caudally adjacent walls of the descending and ascending rami of the Sylvian fissure. Also, the total convoluted surface of the planum temporale was compared with its superficially exposed surface as determined by photographical planimetry after brain section, so that the index of cortical folding of the planum temporale could be estimated. The following results were obtained: Cortical folding of the planum temporale did not differ significantly between left and right hemispheres (p greater than .6). The total and the superficially exposed surface of the planum temporale showed significant leftward asymmetry (p less than or equal to .0078). In contrast, the total surface of cortex buried in the caudal segments of the Sylvian fissure posterior to the planum exhibited significant rightward asymmetry (p less than or equal to .016). The combined cortical surface area buried in the whole posterior Sylvian fissure caudal to the first transverse gyrus did not show significant left-right asymmetry (p greater than 0.3). The data suggest divergent lateral asymmetries in the posterior intrasylvian region with excesses of superior temporal cortex in left hemispheres and of supramarginal cortex in right hemispheres.

Aged↗
PubMed1989

Computed tomographic patterns of proven embolic brain infarctions.

To define patterns of infarction on computed tomography that are characteristic of embolism, as opposed to hemodynamically or microangiopathically induced brain lesions, a consecutive series of 60 patients with acute brain embolism were studied. Strokes were embolic in origin; that is, hemodynamic and in situ thrombotic stroke mechanisms had been excluded. Embolically active, cardiac disease was proved in 42 and was clinically evident in 13 patients. Five patients had suffered a stroke due to catheter-related embolism. Computed tomography revealed pial artery territorial infarction in 55 patients (92%). In 5, the infarction had the size or location (or both) characteristic of lacunes, although shape and lack of multiplicity raised questions about this interpretation. No patient showed a low-flow type of infarction pattern. These findings strongly support the view that (1) except for in situ thrombosis, pial artery territorial infarctions are indicative of an embolic mechanism, and (2) that the mechanism underlying lacunes is hardly, if ever, embolic.

Adolescent↗
PubMed1989

Spinal arteriovenous malformations and fistulae: clinical, neuroradiological and neurophysiological findings.

Twenty-six patients with myelographic signs suggestive of a spinal arteriovenous malformation (AVM) were examined neurologically and neurophysiologically. By selective spinal angiography it was possible to differentiate between dural arteriovenous fistulae (dAVF 20 patients) and intradural AVMs (iAVM, 6 patients). Initial complaints were nonspecific and variable, mainly consisting of sensory disorders and muscle weakness. Later, patients suffered involvement of both the upper and lower motor neurons. There was a high percentage of lower motor neuron lesions (95%), especially in dAVF patients, which were mostly of widespread distribution and included several myotomes. Electrophysiological examination regularly revealed lower neuron involvement, frequently with pathological spontaneous activity in several myotomes, pathological sensory-evoked potentials after tibial nerve stimulation, but normal sensory conduction velocities of the sural nerve, indicating sparing of the sensory ganglion. Frequently there was a discrepancy between the localization of the dural fistula or angioma and the spinal level responsible for clinical symptoms. This suggests that it may be the inadequacy of the venous drainage system to cope with the blood volume rather than the AV-shunt that is responsible for the symptoms. An early diagnosis is essential, as removal of the shunt before there has been progression to severe neurological deficits (paraplegia) is the only way to ensure a satisfactory outcome.

Adult↗
PubMed1989

[How certain is the diagnosis of intracerebral tumor bleeding in magnetic resonance tomography?].

Three patients with intracerebral malignant tumours were examined with high-field strength MRI and CT to determine what differences might exist between a haemorrhagic tumour and a genuine intracerebral haemorrhage. Recent literature hint on characteristic signal abnormalities in comparison to pure intracerebral haematoma. However, two of our three patients showed no significant variation, in particular no delay in the evolution of methaemoglobin and no irregular haemosiderin deposition. Up to now the MRI does not seem to be the method of choice to evaluate the aetiology of intracerebral bleeding.

Adenocarcinoma↗
PubMed1989

Hemodynamics of spinal dural arteriovenous fistulas. An intraoperative study.

Local hemodynamics were investigated during nine operations for spinal dural arteriovenous (AV) fistulas. In eight cases, microvascular Doppler sonography was used to measure flow velocities and vasomotor reactivity to CO2 changes. Intravascular pressure recordings of the draining veins on the medullary surface were performed in nine cases. The flow velocities in dural AV fistula feeding vessels were not as high as has been shown in cerebral angioma feeders. The AV fistula feeders often showed low end-diastolic flow velocities as a sign of increased vascular resistance, even in the presence of a downstream AV fistula, thus proving disturbance of venous outflow from the spinal canal. After excision of the fistula, the circulation of the spinal cord vessels improved, with higher inflow and outflow velocities. In the veins formerly draining the fistula, no further flow could be recorded; however, they did not collapse, indicating that some pressure remained. The mean venous pressure in the dural AV fistulas was about 74% of the systemic arterial pressure. It increased concomitantly with the arterial pressure, which may explain the clinical deterioration that occurs during physical activity. Fistulas with a high shunt volume on angiography showed only moderately increased venous pressures and a more pronounced pressure drop compared to low-volume fistulas. The CO2 reactivity of vessels supplying the spinal cord could be demonstrated in all cases, and was normal before and after removal of the fistula.

Aged↗
PubMed1989

Neurophysiological characteristics of spinal arteriovenous malformations.

The aim of the study was to identify the clinical and neurophysiological pattern of deficits in spinal arteriovenous malformations (AVM) to allow an early diagnosis which is the prerequisite for effective treatment by early surgery or embolization. Among 26 patients with myelographic signs of a spinal AVM, selective spinal angiography disclosed 20 cases with a dural AV-fistula (dAVF) and 6 patients with an intradural AV-malformation (iAVM). Although the main pathogenetic factor in both disorders may be different, clinical and neurophysiological findings proved to be of limited value in differential diagnosis. Clinical symptoms presented by the patients were a variable combination of lower motor neuron lesion, sphincter disturbance, sensory transverse lesion and partly additional signs of upper motor neuron involvement. Electromyography invariably showed an increased rate of polyphasia and frequently pathological spontaneous activity usually in several myotomes. Normal sensory conduction velocity of the sural nerve contrasted with almost regularly pathological SEP's after tibial nerve stimulation. The distribution if clinical and neurophysiological findings suggests rather widespread lesions of the lower cord and/or cauda equina, frequently at a lower level than the angiographically localized shunt. This suggests a vascular myelopathy on the basis of insufficient venous drainage at least for the frequent dural AV-anomaly.

Adult↗