Biomedical subjects

T Czech

Publications and source records attributed to T Czech.

At least 37 records · Page 2Linked to original sources

PubMed2000

Improvement of presurgical patient evaluation by generation of functional magnetic resonance risk maps.

Recent functional magnetic resonance imaging (FMRI) replication studies show a high variability of active voxels within subjects and across runs - a potentially harmful situation for clinical applications. We tried to reduce these uncertainties inherent in current presurgical FMRI. For this, a new high quality head fixation device was used to detect reliably activated voxels over repeated measurements. In addition high correlation thresholds were applied to define the areas with highest probability of activation. The results show a focussing of such functional high risk areas to only a few voxels which localized close to intraoperative cortical stimulation. The generation of such FMRI risk maps may improve validity of clinical localization and facilitate the development of currently missing standards for maximized but still safe tumor resection.

Adult↗

PubMed2000

Intra-arterial thrombolysis for the treatment of perioperative childhood cardioembolic stroke.

Local intra-arterial lysis using recombinant tissue plasminogen activator (rTPA) was performed in a 6 and 2/3-year-old patient with major cardioembolic ischemic stroke 48 hours after intracardiac surgery. Selective application of 2.5 mg rTPA (0.11 mg/kg body weight) resulted in recanalization of the occluded cerebral vasculature with good neurologic recovery.

Cardiac Surgical Procedures↗

PubMed2000

Apoplexy of a pituitary macroadenoma with reversible third, fourth and sixth cranial nerve palsies following administration of hypothalamic releasing hormones: MR features.

Pituitary apoplexy in patients with pituitary macroadenomas can occur either spontaneously or following various interventions. We present a case of a 71-year-old woman who developed third, fourth, and sixth cranial nerve palsies following administration of the four hypothalamic releasing hormones for routine preoperative testing of pituitary function. The MR examination showed interval tumor growth with impression of the floor of the third ventricle. There were also changes in signal intensity characteristics of the mass, suggestive of intratumoral bleeding. A transsphenoidal surgery with subtotal resection of the pituitary adenoma was performed. Microscopical examination revealed large areas of necrosis and blood surrounded by adenomatous tissue. Third, fourth, and sixth cranial nerve palsies completely resolved within 4 months. We conclude that MR imaging is useful in the demonstration of pituitary apoplexy following preoperative stimulation tests, but we suggest that these tests should be abandoned in patients with pituitary macroadenomas.

Abducens Nerve Diseases↗

PubMed2000

Ventricular cerebrospinal fluid and serum concentrations of sTNFR-I, IL-1ra, and IL-6 after aneurysmal subarachnoid hemorrhage.

Postsubarachnoid hemorrhage, systemic inflammatory response syndrome and associated organ system failure are more frequently found in patients in poor neurologic condition. Since subarachnoid hemorrhage causes a profound intrathecal inflammatory response with production of proinflammatory cytokines TNFalpha, IL-1beta, and IL-6, a possible explanation for this association is that brain-derived cytokines may enter the systemic circulation in the presence of postsubarachnoid hemorrhage blood brain barrier disruption to systemically activate inflammatory cascades and thereby contribute to the development of postsubarachnoid hemorrhage systemic inflammatory response syndrome and extracerebral organ system failures. In 44 patients with aneurysmal subarachnoid hemorrhage admitted within 3 days of the initial bleed, extracerebral organ system functions were assessed individually and in aggregate using the modified Multiple Organ Dysfunction Score. Serum and cerebrospinal fluid concentrations of soluble tumor necrosis factor-alpha receptor-I, interleukin-1beta receptor antagonist, and IL-6 were determined during the first 2 weeks after subarachnoid hemorrhage and tested for correlation with (1) admission Hunt-Hess grade, (2) development of systemic inflammatory response syndrome and extracerebral organ system failures, and (3) neurologic outcome. The development of postsubarachnoid hemorrhage systemic inflammatory response syndrome and extracerebral organ system failures was paralleled by a significant increase in serum but not in cerebrospinal fluid levels of soluble tumor necrosis factor-alpha receptor-I and IL-1ra, that is, patients with and without extracerebral organ system failures did not differ in pattern and time course of cerebrospinal fluid cytokine concentrations. In contrast, increasing soluble tumor necrosis factor-alpha receptor-I and interleukin-1beta receptor antagonist serum levels correlated with a higher Multiple Organ Dysfunction score and with individual organ system dysfunctions. Postsubarachnoid hemorrhage, systemic inflammatory response syndrome and extracerebral organ system failures could therefore not be linked to changes in cerebrospinal fluid cytokine concentration profiles.

Adult↗

PubMed2000

Chromogranins in temporal lobe epilepsy.

PURPOSE: Chromogranins are neuropeptide precursors stored in large dense core vesicles. Because physiological functions have been postulated for peptides originating from chromogranins, we investigated the distribution of chromogranins A and B and secretoneurin (a peptide derived from secretogranin II) in the control and epileptic hippocampus of humans and rats. METHODS: Chromogranin immunoreactivity (IR) was investigated in paraformaldehyde-fixed hippocampal specimens from 24 temporal lobe epilepsy patients with intractable seizures, postmortem from 15 patients deceased from nonneurological disorders, in rats 30 days after kainate-induced limbic seizures, and in control rats. RESULTS: In control rats and in humans, chromogranin A and B IR and secretoneurin IR were present in mossy fibers. In addition, chromogranin B IR was found in granule cells, and chromogranin A IR was found in granule and CA2 pyramidal cells in the human hippocampus. In both species, chromogranin B and secretoneurin were unevenly distributed in the molecular layer of the dentate gyrus. The most intriguing change seen in human temporal lobe epilepsy specimens and in the kainic acid model of the rat was the prominent staining of the inner molecular layer, indicating storage of chromogranins A and B and secretoneurin in terminals of reorganized mossy fibers, from which they may be released upon nerve stimulation. CONCLUSION: Chromogranins A and B and secretoneurin are valid markers for hippocampal neurons and delineate epilepsy-induced reorganization of mossy fibers.

Animals↗

PubMed2000

De novo formation and rupture of an azygos pericallosal artery aneurysm. Case report.

An azygos pericallosal artery (APCA) aneurysm is a rare anomaly that is closely associated with saccular aneurysms. This is the earliest report to document de novo formation and rupture of an aneurysm at the bifurcation of an unpaired pericallosal trunk. The authors report the case of a woman who presented at the age of 52 years with subarachnoid hemorrhage (SAH) from the rupture of a newly formed APCA bifurcation aneurysm, 7 years after she had undergone surgery to clip a ruptured anterior cerebral artery aneurysm. De novo formation of aneurysms after SAH rarely occurs and certain risk factors like multiple and familial aneurysms, arterial hypertension, or smoking have been postulated. Late follow-up examination with angiography to detect de novo aneurysms should be considered in patients with this vascular anomaly after SAH.

Aneurysm, Ruptured↗

PubMed2000

Chronic granulomatous meningitis with multiple cranial nerve lesions hydrocephalus, stroke, sinus thrombosis, and epilepsy.

Most frequently, chronic granulomatous meningitis (CGM) is caused by infectious agents. However, in some cases the cause of CGM remains undetermined. It is unclear whether antimicrobial agents, including antituberculous drugs, are helpful in such cases. We describe a 61-year-old man who had multiple cranial nerve lesions, epilepsy, sinus thrombosis, stroke, and hydrocephalus attributable to CGM. Repeated extensive search for a causative agent in the cerebrospinal fluid (CSF) and the meninges remained negative. Only a single culture of the sputum revealed growth of Mycobacterium tuberculosis, which prompted antituberculous therapy with isoniazid, rifampicin, and ethambutol. After 6 months of therapy, neurologic abnormalities were slightly improved. We conclude that antimicrobial/ antituberculous agents have only a minor short-term effect in long-lasting CGM of undetermined cause.

Aged↗

PubMed1999

Genital automatisms in complex partial seizures.

OBJECTIVE: To determine which brain region is responsible for the generation of sexual automatisms. METHODS: Ninety consecutive patients with medically refractory focal epilepsy (74 with temporal lobe and 16 with frontal lobe epilepsy) referred to an epilepsy monitoring unit were studied. The occurrence of the following sexual automatisms was assessed during prolonged video-EEG monitoring: 1) repeatedly grabbing or fondling the genitals and 2) pelvic or truncal thrusting or similar movements. RESULTS: Five patients repeatedly fondled or grabbed their genitals during or immediately after some of their seizures. All five had temporal lobe epilepsy, as evidenced from prolonged video-EEG monitoring, high-resolution MRI, and good to excellent outcome after epilepsy surgery. Sexual automatisms did not occur with frontal lobe epilepsy. CONCLUSION: Sexual automatisms cannot be related exclusively to frontal lobe seizures. As previously proposed, apparently sexual hypermotoric pelvic or truncal movements are common in frontal lobe seizures, but this study suggests that discrete genital automatisms, like fondling and grabbing the genitals, are more common in seizures evolving from the temporal lobe.

Adult↗

PubMed1999

Delayed visual deterioration after surgery for pituitary adenoma.

Despite its description in the literature there remains uncertainty about the incidence, the pathophysiological basis and the best management of a delayed visual deterioration in the presence of an empty sella after surgery for pituitary adenomas. Out of a series of 501 patients with pituitary adenomas operated on at our institution between 1984 and 1996, four patients (0.8%) developed a worsening of their visual function 3 to 37 months after surgery in the absence of tumour recurrence. None of the patients had received radiotherapy. Magnetic resonance imaging (MRI) ruled out compression by tumour and showed herniation of suprasellar structures into an empty sella. In three cases re-operation by a subfrontal approach with freeing of the optic structures from tethering scar tissue led to an improvement of visual deficits. In one case a spontaneous recovery was initiated by a minor head injury. Although apparently a rare event, our cases provide evidence for the occurrence of a potentially reversible delayed deterioration of visual function after surgery for pituitary adenomas. Based on our operative findings and our outcome we recommend re-operation by a transcranial approach in patients in whom repeated ophthalmological testing does not show spontaneous improvement within a short period of time.

Adenoma↗

PubMed1999

Multiple spinal "miliary" hemangioblastomas in von Hippel-Lindau (vHL) disease without cerebellar involvement. A case report and review of the literature.

We report on a 57-year-old male presenting with radicular pain in the nerve roots of L5 and S1 on the right side and dysuria. Magnetic resonance imaging (MRI) of the lumbar spine showed multiple (up to 20) small, intradural enhancing nodules attached to the cauda equina down to the sacrum, the largest 1 cm in diameter at the level Th12/L1 compressing the conus. Additionally, small nodules in the cervico-thoracal region adjacent to the cord, but no cerebellar or cerebral abnormalities, were detected in a consecutive MRI of the remaining neuroaxis. The histology of a resected lesion at Th12/L1 revealed hemangioblastoma of the reticular type. Together with a history of left eye enucleation performed 17 years ago for angiomatosis of the retina and the immunohistochemical detection of von Hippel-Lindau (vHL) protein within the removed spinal hemangioblastoma, a diagnosis of vHL disease was established. Family history and screening for visceral manifestations of vHL disease were negative. In contrast to cerebellar or solitary spinal hemangioblastomas, multiple spinal hemangioblastomas without cerebellar involvement in vHL represent unusual manifestations. Unlike the case for solitary lesions in non-syndromic patients, a surgical cure does not seem feasible in this case. The role of treatment modalities is discussed.

Biomarkers, Tumor↗

PubMed1999

Proliferative activity as measured by MIB-1 labeling index and long-term outcome of visual pathway astrocytomas in children.

Although most visual pathway tumors are low-grade gliomas their biologic behavior is highly unpredictable. In order to determine whether assessment of proliferative activity can assist in predicting tumor behavior, we studied the MIB-1 labeling indices (MIB-1 LIs) in surgical specimens and monitored tumor growth in 31 consecutive children operated on between 1978 and 1997. The MIB-1 LIs at diagnosis varied from 0-10.6% (mean +/- SD, 3.27 +/- 2.49%). Tumor progression occurred in 19 patients leading to death in seven, three of whom had neurofibromatosis type 1 (NF1). No association between MIB-1 LI at initial diagnosis and both progression free and overall survival was apparent. However, the MIB-1 LIs increased to 15.2% and 18% in two patients with NF1 who developed highly malignant gliomas 6 and 6.5 years after irradiation. In the remaining patients the MIB-1 LIs did not change significantly over time in a total of 17 repeat surgeries. Three patients with LIs of 6.8%, 10.6% and 8.8% are stable after 6, 4.5 and 3.5 years with partial resection, biopsy and subtotal resection, respectively, and no further therapy in the first two and chemotherapy in the latter. Three patients (10%) with LIs of 6.4%, 4.8% and 2.2% either presented with or developed leptomeningeal spread during follow-up. While MIB-1 LI does not appear to assist in clinical decision making patient numbers were too small to find out whether response to chemotherapy varies with proliferative potential.

Adolescent↗

PubMed1999

Resection of a Langerhans cell histiocytosis granuloma of the hypothalamus: case report.

The natural course and optimal treatment for isolated hypothalamic Langerhans cell histiocytosis (LCH) are unknown. We describe an adult female in whom total resection of a hypothalamic LCH granuloma was performed 12 years after transphenoidal resection of a pituitary adenoma. A retrospective review of the histological specimen of the first operation revealed CD1a positive cells characteristic of LCH along with a plurihormonal adenoma 12 years earlier. No other manifestations of LCH were found and MRI of the brain at the last follow-up 4 years after surgery did not show any recurrent or additional lesion. The diagnosis of isolated hypothalamic LCH is only possible by biopsy and our case demonstrates the feasability of a gross total resection in certain cases.

Female↗

PubMed1999

Extracerebral organ dysfunction and neurologic outcome after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: To analyze the influence of extracerebral organ system dysfunction after aneurysmal subarachnoid hemorrhage (SAH) on mortality and neurologic outcome. DESIGN: Observational study with retrospective data extraction. SETTING: Neurosurgical intensive care unit (NICU) at a primary level university hospital, supervised and staffed by both members of the Clinic of Neurosurgery and the Clinic of Anesthesiology and General Intensive Care. PATIENTS: Two hundred forty-two patients treated for intracranial aneurysm rupture within 7 days of the most recent SAH. INTERVENTIONS: Routine neurosurgical interventions for obliteration of the ruptured aneurysm (microsurgery, Guglielmi Detachable Coils embolization) and for treatment of posthemorrhagic hydrocephalus (ventriculostomy, cerebrospinal fluid shunt implantation). MEASUREMENTS AND MAIN RESULTS: Respiratory, renal, hepatic, cardiovascular, and hematologic organ system functions were evaluated both individually and in aggregate by using a modified version of the Multiple Organ Dysfunction (mMOD) score. Of 1,452 organ system functions assessed in 242 patients during their NICU stay, 714 organ system functions were intact (cerebral: 0, extracerebral: 714), 556 organ systems had mild-to-moderate dysfunctions (mMOD scoremax 1-2 for the affected organ system; cerebral: 153, extracerebral: 403), and 182 organ systems failed (mMOD scoremax 3 for the affected organ system; cerebral: 89, extracerebral: 93). Severity of extracerebral organ system dysfunctions correlated with the degree of neurologic impairment (Hunt and Hess [H&H] score) in a graded fashion. Similarly, the chance to develop systemic inflammatory response syndrome (SIRS) during the NICU stay increased with increasing admission H&H grade. The incidence of SIRS and septic shock was 29% and 10.3%, respectively. The mortality rate was 40.2% in patients with SIRS and 80% for patients suffering septic shock. Seventy-seven percent of extracerebral organ system failures (OSFs) occurred in conjunction with SIRS: 51% of respiratory OSFs, 97% of renal OSFs, 100% of hepatic OSFs, 96% of cardiovascular OSFs, and 73% of hematopoietic OSFs. Both CNS dysfunction and extracerebral organ system dysfunctions were significantly related to neurologic outcome. The probability of unfavorable neurologic outcome significantly increased with both decreasing cerebral perfusion pressure (CPP) and increasing severity of extracerebral organ dysfunction. CONCLUSION: Aneurysmal SAH and its neurologic sequelae accounted for the principal morbidity and mortality in the current series. Development of extracerebral organ system dysfunction was associated with a higher probability of unfavorable neurologic outcome. Systemic inflammation (SIRS) and secondary organ dysfunction were the principal non-neurologic causes of death.

Adult↗

PubMed1999

Chronic shunt-dependent hydrocephalus after early surgical and early endovascular treatment of ruptured intracranial aneurysms.

OBJECTIVE: The goal of this study was to document the influence of the treatment method (early surgery versus early endovascular treatment) on the development of chronic shunt-dependent hydrocephalus in a series of 242 patients treated within 7 days after aneurysmal subarachnoid hemorrhage (SAH). METHODS: The following parameters were prospectively recorded in a computerized database and retrospectively analyzed for association with chronic shunt-dependent hydrocephalus: 1) Hunt and Hess grade, 2) Fisher computed tomographic grade, 3) incidence of repeat SAH, 4) aneurysm location, and 5) treatment method (early surgery versus early endovascular treatment). RESULTS: Forty of 187 patients (21.4%) who survived the SAH and its neurological and/or medical sequelae underwent definitive shunting for treatment of chronic hydrocephalus. The rate of shunt dependency was positively correlated with a higher Hunt and Hess grade (P < 0.001), a higher Fisher computed tomographic grade (P = 0.003), the occurrence of intraventricular hemorrhage (P < 0.001), repeat SAH (P = 0.003), and aneurysms arising at the anterior communicating artery (P < 0.001). CONCLUSION: The results of the present study indicate that the treatment method used does not affect the risk of the later development of chronic shunt-dependent hydrocephalus (early surgery, 23.2% [29 of 125]; early endovascular treatment, 17.7% [11 of 62]; P = 0.45).

Adult↗

PubMed1999

A case of startle epilepsy and SSMA seizures documented with subdural recordings.

PURPOSE: To study the mechanisms of startle-induced supplementary sensorimotor area (SSMA) seizures. METHODS: We present a patient investigated with indwelling subdural grid electrodes covering both the SSMA and the dorsolateral frontal lobe. RESULTS: We found a simultaneous seizure onset in the right dorsolateral premotor cortex and the right SSMA. High-resolution magnetic resonance imaging (MRI) showed a small subcortical lesion adjacent to the right SSMA. The patient became seizure free after resection of the lesion and the ictal-onset zone. CONCLUSIONS: We conclude that an extended region of abnormally excitable tissue within the frontal lobe could facilitate the generation of startle-induced seizures. We speculate that a widespread epileptogenic zone could help to explain why some patients with SSMA or dorsolateral frontal lobe seizures are more likely to have startle-induced seizures.

Adult↗

PubMed1999

Regional cerebral blood flow during temporal lobe seizures associated with ictal vomiting: an ictal SPECT study in two patients.

PURPOSE: Ictal vomiting represents a rare clinical manifestation during seizures originating from the temporal lobes of the nondominant hemisphere. The precise anatomic structures responsible for generation of ictal vomiting remain to be clarified. Ictal single photon emission computed tomography (SPECT), which allows one to visualize the three-dimensional dynamic changes of regional cerebral blood flow (rCBF) associated with the ongoing epileptic activity, should be useful to study the brain areas activated during ictal vomiting. METHODS: We performed ictal Tc-HMPAO SPECT scans in two patients with mesial temporal lobe epilepsy (MTLE) whose seizures were characterized by ictal retching and vomiting. MTLE was documented by typical clinical seizure semiology, interictal and ictal EEG findings, hippocampal atrophy on magnetic resonance imaging (MRI) scan, and a seizure-free outcome after selective amydalohippocampectomy. In both patients, seizures originated in the nondominant temporal lobe. We obtained accurate anatomic reference of rCBF changes visible on SPECT by a special coregistration technique of MRI and SPECT. We used ictal SPECT studies in 10 patients with MTLE who had seizures without ictal vomiting as controls. RESULTS: In the two patients with ictal vomiting, we found a significant hyperperfusion of the nondominant temporal lobe (inferior, medial, and lateral superior) and of the occipital region on ictal SPECT. In patients without ictal vomiting, on the contrary, these brain regions never were hyperperfused simultaneously. CONCLUSIONS: Ictal SPECT provides further evidence that activation of a complex cortical network, including the medial and lateral superior aspects of the temporal lobe, and maybe the occipital lobes, is responsible for the generation of ictal vomiting.

Adult↗

PubMed1999

Growing blood clot mimicking an aneurysm on postoperative computerized tomography and magnetic resonance imaging studies. Case report and review of the literature.

The authors describe the case of a 15-year-old boy who underwent resection of a large left temporal tumor. During a normal postoperative course, computerized tomography (CT) scanning demonstrated a spherically hyperdense structure near the internal carotid artery, enlarging on a control CT scan. A suspected false aneurysm was confirmed on magnetic resonance imaging; angiographic studies were negative. The authors believed they were dealing with a thrombosed false aneurysm and they performed operative revision. Intraoperatively the "aneurysm" could be dissected off the internal carotid artery and no lesion of the arterial wall was obvious. Histological findings showed a fresh blood clot. This case demonstrates that a blood clot may mimic an aneurysm on CT and magnetic resonance studies, which has not been described earlier. The origin of the blood clot remains unclear.

Adolescent↗

PubMed1998

Hyaluronidase additional to standard chemotherapy improves outcome for children with malignant brain tumors.

Ex vivo experiments with vital brain tumor samples show that hyaluronidase enhances the permeation of carboplatin into tumor tissue with a matrix rich in hyaluronic acid. We achieved long-lasting second remissions for children with relapsed malignant brain tumors treated with carboplatin, etoposide and this enzyme. Thereafter, we initiated a pilot study where we added hyaluronidase to the first line standard therapy to prevent the deadly relapses right from the beginning. All 19 patients with malignant brain tumors admitted to our pediatric neurooncological center from 1992 to 1994 were included in the study. Kaplan-Meier estimation of event-free survival and overall survival after 3 years follow-up indicates a significantly better outcome for the hyaluronidase-treated group. The children receiving supportive hyaluronidase suffered significantly less relapses (P = 0.034) and had a significantly better chance for survival (P = 0.045) compared to the historical control of 21 children treated with the same standard regimen but without supportive hyaluronidase (product limit analysis and the log-rank test, P < 0.05). Children aged >3 years receiving hyaluronidase together with primary treatment seemed to gain the most benefit.

Antineoplastic Combined Chemotherapy Protocols↗