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L Solymosi

Publications and source records attributed to L Solymosi.

At least 55 records · Page 3Linked to original sources
PubMed1998

Depth electrode implantation in the length axis of the hippocampus for the presurgical evaluation of medial temporal lobe epilepsy: a computed tomography-based stereotactic insertion technique and its accuracy.

OBJECTIVE: An individualized computed tomography-based stereotactic technique for the longitudinal insertion of intrahippocampal electrodes is presented and its accuracy described. METHODS: The technique makes use of one well reproducible target in the hippocampal head and of the approximate inclination of the anteroposterior length axis of the hippocampus, for which the orbital floor is taken as an auxiliary landmark. It was used in 141 patients with medically intractable complex partial seizures. In 106 patients, magnetic resonance imaging (MRI) was available for assessment of implantation accuracy. Each of the 212 electrodes was plotted on topographic drawings and its goodness of fit rated. RESULTS: Whereas hippocampal head and body were hit by 97 and 96% of the electrodes, respectively, the amygdala was hit by only 75% of the electrodes and mainly at its basal margin. For 93% of the electrodes, the inclination in a sagittal plane corresponded exactly to that of the hippocampus. The implantation morbidity amounted to 5.7%, whereas permanent neurological deficit occurred in one (0.7%) of the 141 patients. CONCLUSION: This computed tomography-based protocol proved to be reliable and hence can be considered as an adequate alternative to MRI-based stereotactic implantation if MRI is not available or if a single MRI-based stereotactic set-up is unreliable because of intolerable distortions.

Amygdala↗
PubMed1998

Enlarged cerebrospinal fluid spaces in opiate-dependent male patients: a stereological CT study.

Computed tomography was performed in 9 male patients with a diagnosis of opiate dependence and in 9 age-matched psychiatric controls (neurotic depression). Patients with a history or diagnosis of another substance dependence (alcohol, cocaine, cannabis) were excluded from the study. The volumes of internal and external components of cerebrospinal fluid (CSF) were measured with a point-counting stereological method. Analysis of variance with age as a covariate revealed a significant enlargement of external and external CSF spaces in male patients with opiate dependence. There was no significant correlation between the length of opiate dependence and the volumes of internal and external CSF spaces. The present results suggest that opiate dependence is associated with structural brain alterations. However, the relationship between opiate dependence and structural brain changes is complex and still not well understood.

Adult↗
PubMed1998

Fusiform dilatations of the internal carotid artery following surgery for pediatric suprasellar tumors.

Fusiform dilatations of the internal carotid artery (FDCA) represent a vascular complication following surgery for suprasellar tumors in children. In a long-term follow-up of 62 children we identified 7 children (11.3%) with a FDCA. In all children the FDCA was present within 15 months following surgery. It was not related to radiotherapy or a distinct histology. In 3 children the FDCA remained unchanged during the follow-up, in 3 children there was a progression and 1 child revealed a regression within 6 months. Clinically the FDCA was inapparent in all cases and not treated. In a follow-up study of an adult population who underwent surgery for suprasellar tumors no case of FDCA was encountered. Potential pathomechanisms and indications for treatment are discussed.

Adolescent↗
PubMed1998

[An alternative dorsal fusion technique after transoral dens resection in basilar impression with atlas assimilation].

Current therapy of basilar impression includes transoral dens resection. The essential disadvantage of this procedure is the instability of C1/C2 due to loss of the transverse ligament. We describe two patients in whom this instability was treated by modified screwing. Using MAGERL-screws between C0-C2 an interposition of an iliac graft between the occiput and the arc of C2 was made. Neurological symptoms improved in both patients postoperatively. In both cases stable fusion C0/C2 was achieved with an additional treatment with a HALO-fixateur for eight weeks. In our opinion the combined transoral/dorsal procedure is most suitable and efficient in treatment of basilar impressions. By this approach both, decompression of the myelon as well as stable fusion C0/C2, is achieved.

Adolescent↗
PubMed1997

Diagnosis and treatment of frontobasal skull fractures.

During a five-year-period (January 1990 to December 1994) a total of 67 patients were operated on for frontobasal skull fractures. The indication for surgical treatment was based on the evidence of fractures encroaching paranasal sinuses or the cribriform plate on high-resolution axial or coronal CT scans. The following clinical signs indicating frontobasal trauma were observed: 25 patients (37%) showed rhinoliquorrhea, 14 (21%) had raccoon's eyes, and 2 (3%) had meningitis. Distinct dura laceration was observed intraoperatively in 64 of 67 patients (96%). In our experience, high resolution CT has proven to be a sensitive diagnostic tool for frontobasal skull fractures. With respect to the high coincidence of fractures and dura lacerations, the indication for surgical treatment based on CT findings seems to be justified.

Adolescent↗
PubMed1997

Local intra-arterial fibrinolysis in thromboembolic "T" occlusions of the internal carotid artery.

Local intra-arterial fibrinolysis (LIF) is considered to support spontaneous recanalisation, which does not usually occur fast enough to prevent an infarct. Therefore, LIF may, at least theoretically, be especially useful in occlusions with large thromboembolic masses. We report our experience of LIF with urokinase in 12 patients with combined occlusions of the distal internal carotid, anterior and middle cerebral arteries (carotid "T" occlusions). There were 4 patients who survived with minor neurological deficits (Barthel index > 90), 4 with major deficits (Barthel index 40-55) and 4 patients died: in one of the last group a haematoma developed in a middle cerebral artery infarct. Recanalisation and clinical outcome were parallel in 10 of 12 patients. A patient with excellent leptomeningeal collaterals had a good clinical outcome despite only moderate recanalisation, and the patient with the parenchymal haematoma had good recanalisation. Recanalisation with urokinase in carotid "T" occlusions is often poor, but outcome can be good if treatment starts early, recanalisation succeeds and leptomeningeal collateral supply is good. Our results therefore encourage us, unlike previously reported series, to perform LIF in this type of occlusion.

Adult↗
PubMed1997

Improved CT diagnosis of acute middle cerebral artery territory infarcts with density-difference analysis.

A new postprocessing method is described for CT detection of acute middle cerebral artery (MCA) territory infarcts by histograph analysis of density values. The density values in each CT slice were histographically recorded for each hemisphere. A density-difference diagram was calculated by digital subtraction of the histogram of the left hemisphere from that of the right. Pixels within the highest density-difference ranges were highlighted. To investigate the value of this method CT studies of 30 patients with acute MCA territory infarcts and of 15 normal CT studies were analysed by two radiologists and neurosurgeons. CT images with and without postprocessing were assessed for the presence, site and size of infarcts. Follow-up CTwas used as control. With density-difference analysis (DDA) the detection rate for infarcts increased significantly (96 % compared to 61 %). In no case was a correct diagnosis made on the unpostprocessed images falsely revised with DDA. All normal CT studies were detected correctly using DDA.

Adolescent↗
PubMed1997

Sarcoidosis presenting as an intra- or extra-axial cranial mass: report of two cases.

Sarcoidosis may also present as an extra- or intra-axial mass involving the central nervous system. These lesions are sometimes operated upon, because a neoplasm is suspected. We report two cases of unusual tumour-like extra- and intra-axial sarcoidosis. The extra-axial mass was just medial to the jugular foramen. Its morphology and signal characteristics differed from the more common lesions in this area. The intra-axial mass was in the temporal lobe, with only minor leptomeningeal involvement. Extra-axial sarcoidosis can be confused with a meningioma because these lesions can give relatively low signal on T2-weighted images. Intra-axial masses are presumed to represent a propagation and fusion of multiple leptomeningeal granulomas through the Virchow-Robin spaces in the brain; this pattern can be sought on contrast-enhanced T1-weighted images.

Aged↗
PubMed1997

[Detectability of new medial infarcts by CT: appearance of ischemic signs].

PURPOSE: To evaluate the detectability of acute middle cerebral artery (MCA) infarctions by CT with regard to the time interval after symptom onset and to the infarction size. Analysis of the chronological appearance of signs of ischaemia. MATERIAL AND METHODS: Two examiners retrospectively and independently evaluated CT scans from 171 patients with acute MCA infarctions performed within 24 hours after onset of symptoms. RESULTS: 92, respectively 87% of the Infarctions were correctly diagnosed. The detection rate did not increase after the first hour after onset of symptoms. All MCA infarctions involving the lentiform nucleus, but only 83% of the infarctions covering < 33% of the MCA area, were recognised. The hyperdense middle cerebral artery sign (HMCA5) was present in 75% of the infarctions in the first 90 minutes and in 15% from hour 12 to 24. Hypodensity of the lentiform nucleus appeared within 150 minutes, hypodensity of the convexity cortex at the earliest 60 minutes after onset of symptoms. CONCLUSIONS: The detection rate of acute MCA infarctions corresponds with the infarction size, but does not significantly change after the first hour after symptom onset.

Adult↗
PubMed1997

Preoperative risk assessment for carotid occlusion by transcranial Doppler ultrasound.

OBJECTIVES: An endovascular carotid balloon occlusion test with continuous intracranial monitoring by transcranial Doppler sonography was performed in 55 patients for prediction of tolerance of a required permanent occlusion of the carotid artery. METHODS: Blood flow velocities of the ipsilateral middle cerebral artery during occlusion were recorded and compared with clinical tolerance during an occlusion test as well as with postoperative outcome after an eventual permanent occlusion. To stress the capacity of the cerebral circulation to tolerate the occlusion acetazolamide was injected before occlusion in all patients. RESULTS: The onset of neurological symptoms during temporary occlusion was dependent on the percentage fall of mean blood flow velocity relative to baseline rather than on absolute flow velocities during the time of occlusion. Patients with a fall of mean flow velocity of less than 30% tolerated temporary and permanent occlusion, with the exception of two patients who developed an infarction due to thromboembolism after iatrogenic sacrifice of the carotid artery. Patients with a major decrease developed neurological symptoms during occlusion in 55% and, in cases of carotid ligation, a haemodynamic infarction occurred. CONCLUSION: The results show that transcranial Doppler monitoring as a part of an endovascular balloon occlusion test may be a reliable technique for preoperative risk assessment for permanent occlusion of the carotid artery.

Adult↗
PubMed1997

Confirmation of CT criteria to distinguish pathophysiologic subtypes of cerebral infarction.

PURPOSE: To determine whether cerebral infarctions classified as embolic or hemodynamic by their appearance on CT scans reflect distinct pathophysiologic entities. METHODS: Cerebral infarctions were retrospectively classified into two groups according to their morphologic appearance on CT scans: territorial infarctions and watershed, or terminal supply area, infarctions. Specific CO2 reactivity for both groups of patients was determined with the xenon-133 method and 32 stationary detectors. Twenty-one patients with unilateral, supratentorial, ischemic cerebral infarctions were selected. CT findings were highly suggestive of a territorial infarction in 14 patients (mean age, 56 years) and of a watershed infarction in seven patients (mean age, 52 years). RESULTS: The initial slope index of the territorial and watershed infarction groups during CO2 inhalation was 55.1 +/- 2.4 sec-1 and 52.0 +/- 1.9 sec-1, respectively, in the infarcted hemispheres and 58.3 +/- 2.3 sec-1 and 55.1 +/- 1.5 sec-1, respectively, in the noninfarcted hemispheres. CO2 reactivity of the unaffected detectors was 1.75 +/- 0.3 sec-1 mm Hg-1 and 1.51 +/- 0.2 sec-1 mm Hg-1 for the territorial and watershed infarction groups, respectively. CO2 reactivity of the affected detectors was 1.75 +/- 0.3 sec-1 mm Hg-1 and 1.27 +/- 0.2 sec-1 mm Hg-1 for the two groups, respectively. The CO2 reactivity difference between affected detectors of the hemodynamic group and age-matched healthy control subjects was significant. CONCLUSIONS: The difference in CO2 reactivity between the two groups supports the concept that CT criteria can identify two pathophysiologic entities. In addition, we conclude that during the chronic stage, lower CO2 reactivity of the watershed infarction indicates that the global hemodynamic situation in these infarcts is more severely compromised than in territorial infarctions.

Aged↗
PubMed1997

[Incidence of lesions described by magnetic resonance imaging in the clarification of focal epilepsy of frontal and temporal origin].

AIM: Today, MRI is an integral part of the presurgical evaluation of patients suffering from partial epilepsy. These patients frequently show focal morphological abnormalities with potential epileptogenic character and surgical resection of these lesions is associated with superior postsurgical outcome as to seizure frequency. Apart from easily detectable defects, such as post-traumatic lesions or cerebral infarction, as wide variety of mainly small abnormalities can be detected using MRI. METHODS: In this study, 484 patients suffering from partial epilepsy of temporal or frontal onset were evaluated for the incidence of different lesions in this population. RESULTS: All lesions found were included without evaluating their potential epileptogenicity, which remains to be proven using other procedures (EEG, SPECT, PET, etc.). Involvement of the hippocampal formation was a major finding in temporal lobe epilepsy, which could be detected as sclerosis (T2w-images), atrophy (T2w-TSE or T1w-IR-images) or both (15%). In addition and in declining frequency various tumors (14%), post-traumatic lesion (-5%), and focal cortical dysplasia or other disturbances of cortical integrity (-4%) were found. These lesions are detectable with best contrast on different sequences. As a consequence it is suggested to acquire sequences in 3 dimensions including a T1w-SE, two (coronal and axial) double-echo-SE sequences and similarly two T1w-IR-sequences. The application of contrast media can be restricted to special questions, derived either from the first imaging results or from the patients history. CONCLUSION: Using qualitative data for interpretation, the sensitivity as to the detection of any focal pathology of a recent-generation MRI in this population was 75%, with 79% for temporal lobe epilepsies and 67% for frontal lobe epilepsies. Quantitative measurements of hippocampal volume or signal seem to be able to increase the sensitivity of the method.

Atrophy↗
PubMed1996

Herniation of the spinal cord 38 years after childhood trauma.

We report an unusual post-traumatic spinal cord herniation, which became symptomatic 38 years after the trauma. A 44-year-old man presented with a 2-year history of increasing impotence, neuropathic bladder dysfunction and dissociated sensory loss below the level of T6. At the age of 6 years he had a severe blunt spinal injury with transient paraparesis. MRI revealed right lateral and ventral displacement of the spinal cord at the T5/6 level. The spinal cord was surgically exposed and found to herniate through a ventral defect of the arachnoid membrane and the dura mater. As there were no other events that could have precipitated spinal cord herniation the reported blunt trauma in childhood is the most likely cause for the spinal cord herniation in this patient.

Adult↗
PubMed1996

[Endovascular balloon occlusion test of the internal carotid artery with increased hemodynamic monitoring for determination of circulatory reserve before planned carotid occlusion].

PURPOSE: To evaluate stroke risk assessment of balloon test occlusion of the internal carotid artery (ICA) with enlarged haemodynamic monitoring prior to permanent ICA occlusion. MATERIAL AND METHODS: 24 patients with cervical metastasis (n = 18), cavernous meningiomas (n = 3) or inoperable cavernous aneurysms (n = 3) were examined. The test occlusion was monitored by EEG, neurological examinations and transcranial Doppler sonography of the ipsilateral middle cerebral artery with evaluation of the cerebrovascular reserve capacity. Additionally 99mTc-HMPAO-SPECT imaging was added showing the perfusion during test occlusion. RESULTS: In one (4%) patient the test occlusion had to be interrupted previously due to an acute neurological deficit. This patient and two (8%) patients with highly pathological test results in SPECT and TCD were excluded from permanent carotid occlusion. In 6 (25%) patients quantitative TCD monitoring could improve the stroke risk assessment by differentiating the patients in a low and high risk group. 6 (25%) patients were definitely occluded without haemodynamic complications, but two patients suffered from embolic infarctions which cannot be predicted by this procedure. CONCLUSIONS: The multimodal balloon test occlusion with enlarged haemodynamic monitoring allows haemodynamic stroke risk assessment prior to permanent occlusion of the ICA.

Adult↗
PubMed1996

Subarachnoid hemorrhage of unknown etiology.

During a 10-year-period, 80 of 510 (16%) patients with primary subarachnoid hemorrhage (SAH) had negative angiographic studies. On admission, 70 of 80 patients (88%) were in grades I-II according to Hunt and Hess, 9 (11%) in grade III, and 1 (1%) in grade IV. The most frequent CT feature was preponderance of subarachnoid blood in the peripontine cistern as observed in 35 of 51 cases (69%) in whom blood was visible on CT. During hospitalization, 3 patients (4%) rebled, and 3 others (4%) had an infarction. However, in all of these complicated cases maximum hemorrhage was outside the peripontine cistern. Outcome after hospitalization as assessed by the Glasgow-Outcome-Scale (GOS) was favorable (GOS 1 and 2) in all patients who had maximum blood in the peripontine cistern, but only in 62% showing preponderance of blood outside the peripontine cistern, and 4 of them (25%) had died (GOS 5). These differences are statistically significant (p < 0.001). Long-term outcome of 56 patients as graded according to the Activities of Daily Living (ADL) system was favorable in 88% of cases with peripontine hemorrhage who returned to normal activities (ADL 1). At the same time, another patient with diffuse hemorrhage had died. Thus, overall mortality was 8.9% at a mean observation time of 5.5 years. In conclusion, SAH of unknown etiology generally has a good prognosis, although a nonneglegible percentage of patients have persistent minor side-effects. In our experience, maximum blood in the peripontine cistern particularly indicates a favorable outcome, since all patients with this CT pattern survived in a good condition.

Adult↗
PubMed1996

Surgical treatment of extratemporal epilepsy: clinical, radiologic, and histopathologic findings in 60 patients.

PURPOSE AND METHODS: The aim of this study was to analyze clinical, radiologic, and histopathologic findings in 60 consecutive patients with medically intractable extratemporal epilepsy who were operated on between November 1987 and May 1993. RESULTS: Histologically, there were distinct structural abnormalities in 50 (83%) of the surgical specimens. Signal abnormalities on magnetic resonance imaging (MRI) were present in all patients with neoplastic lesions (n = 17) and in 94% of patients with nonneoplastic focal lesions (n = 32). Overall, structural abnormalities were detected by MRI in 47 (96%) of 49 patients with focal lesions. During a mean follow-up of 4 years, 30 (54%) patients remained completely seizure free, 11 (20%) had < or = 2 seizures per year, seven (12%) showed a seizure reduction of > or = 75%, and eight (14%) had < 75% reduction in seizure frequency. The fraction of seizure-free patients was 12 (80%) of 15 in patients with neoplastic lesions, 16 (52%) of 31 in patients with nonneoplastic focal lesions, and two (20%) of 10 for those without histopathologic abnormalities. The differences in seizure outcome between patients with and without focal lesions were statistically significant (p < 0.05), if seizure-free outcome was compared with persistent seizures. CONCLUSIONS: Focal lesions and particularly neoplasms are associated with improved postoperative seizure control compared with patients without histopathologic abnormalities. We advise caution in considering surgery to treat extratemporal epilepsy in patients who have normal MRI scans, because the outcome with the approach described in this study is poor in such cases.

Adolescent↗
PubMed1996

Presence and removal of arteriovenous malformation: Impact of regional cerebral blood flow, as assessed with xenon/CT.

In 26 patients with supratentorial AVMs and 1 patient with a dural arteriovenous fistula, the regional cerebral blood flow (rCBF) was assessed by means of xenon-enhanced computed tomography (Xe/CT) before and after complete resective surgery. Each assessment comprised an acetazolamide challenge in order to check the cerebrovascular reserve capacity. While scanning through the AVM was purposely avoided, a single brain slice at the level of the basal ganglia was examined. Five regions of interest (ROIs) in gray matter of the AVM-bearing hemisphere were compared to the contralateral ROIs and categorized into 7 CBF groups. Interhemispherical differences exceeding 20% of the contralateral value in either direction were considered to the significant. AVM-related (AVM-R) and AVM-non-related (AVM-NR) ROIs were looked at separately. Before surgery, all possible rCBF patterns were found, including a normal rCBF as well as a reduced or an increased rCBF, either in AVM-R, AVM-NR, or both. After AVM removal, a rCBF increase in AVM-R is relatively rare, whereas a rCBF decrease is twice as frequent. A rCBF drop to a level of impaired reserve capacity correlates with the occurrence of post-operative neurological deficit.

Acetazolamide↗