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G Schuierer

Publications and source records attributed to G Schuierer.

At least 19 recordsLinked to original sources
PubMed2002

[Presenile dementia in polycystic lipomembranous osteodysplasia].

We present a 36-year-old woman with a 3-year history of cognitive decline followed by development of a small stepped gait and urinary and fecal incontinence. Workup revealed multiple bone cysts documented by X-ray and idiopathic hyperprolactinoma. An MRI confirmed the CT finding of massive bilateral basal ganglia calcification. This is the first case of polycystic lipomembranous osteodysplasia described in Germany. We conclude that patients with presenile dementia, psychosis, or early-onset Parkinsonism associated with basal ganglia calcification should undergo X-rays of hand and feet to rule out polycystic lipomembranous osteodysplasia.

Adult↗
PubMed2001

Temporal hypometabolism at the onset of cryptogenic temporal lobe epilepsy.

Most patients with intractable temporal lobe epilepsy (TLE) exhibit temporal glucose hypometabolism. The reasons for the development of this abnormality are as yet unclear. The current notion is that an initial injury causes seizures, which in turn give rise to hypometabolism. The aim of this study was to assess whether temporal reductions in glucose metabolism in non-lesional TLE are the result of repeated seizures or whether hypometabolism represents an initial disturbance at the onset of disease. Glucose consumption was assessed with fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) in 62 patients with cryptogenic non-refractory TLE in different stages of disease. Twelve subjects without neurological illness served as controls. Patients with onset of epilepsy at least 3 years prior to the PET scan were defined as having chronic TLE. Using this criterion, the whole patient cohort included 27 patients with de novo TLE and 35 patients with chronic TLE. The groups were matched for age and sex. The appearance of high-resolution magnetic resonance images of the brain was unremarkable in all patients. In the total cohort, number, duration and frequency of seizures had a significant relation to the magnitude of hypometabolism. Temporal hypometabolism was exhibited by 26 of the 62 patients (42%), including 8 out of 27 (30%) with newly diagnosed TLE and 18 out of 35 (51%) with chronic TLE. The disturbances were more extensive and more severe in patients with chronic TLE. It is concluded that temporal hypometabolism may already be present at the onset of TLE, but is less frequent and less severe in newly diagnosed than in chronic TLE. The metabolic disturbance correlates with the number of seizures. These findings suggest that an initial dysfunction is present in a considerable number of patients and that hypometabolism is worsened by continuing epileptic activity.

Adolescent↗
PubMed2001

Disturbed benzodiazepine receptor function at the onset of temporal lobe epilepsy--lomanzenil-binding in de-novo TLE.

PURPOSE: Epileptogenic foci exhibit disturbed function at the level of the benzodiazepine receptor. The aim of our study was to investigate the incidence of focal reductions of temporal benzodiazepine receptor binding (BRB) as assessed by scintigraphy with 123I-iomazenil in patients with denovo temporal lobe epilepsy (TLE). METHODS: Forty adult patients (age: 34+/-12 years) with cryptogenic denovo TLE underwent scintigraphy with 123I-iomazenil. In all patients, symptomatic epilepsy was excluded by clinical investigation and MRI. The median duration of TLE was seven months, and the patients had a median of three documented seizures in their history of disease. BRB was quantified in four temporal regions covering the whole temporal lobe. Temporal asymmetry values (ASY) were compared with data determined in 13 age-matched controls yielding Z-scores for global and regional temporal BRB. RESULTS: A significant reduction of temporal BRB was found in 19 of the 40 patients (48 %), mainly in mesial temporal regions; temporal BRB asymmetries were also found in patients with a short history of seizures and low seizure frequency (< or = 1 year; n = 32, 13/32 (41 %)). Only in the entire cohort did the magnitude of temporal reduction of BRB correlate with the duration of TLE as well as with the number of previous partial seizures (r = 0.40 and r = 0.36; p < 0.03, respectively). CONCLUSIONS: Foci of decreased BRB can already be detected at the onset of TLE; their magnitude is related to ongoing epileptic activity.

Adolescent↗
PubMed2000

Cerebral MR perfusion imaging: first clinical application of a 1 M gadolinium chelate (Gadovist 1.0) in a double-blinded randomized dose-finding study.

The purpose of this study was to evaluate efficacy and safety of the 1 M gadolinium chelate Gadovist 1.0 for assessment of cerebral hemodynamics with dynamic susceptibility contrast-enhanced magnetic resonance (MR) imaging. Eighty-nine patients with carotid artery stenosis or cerebral infarcts were included in this multicenter, double-blinded study using five dose groups from 0.1 to 0.5 mmol/kg. Imaging was performed with 1-T scanners using a T2*-weighted fast low-angle shot (FLASH) sequence. Dose-dependent changes in quantitative and qualitative parameters describing signal-time curves and relative regional cerebral blood volume maps were investigated. For safety evaluation, vital signs, clinical and laboratory tests, and adverse events were assessed. The quantitative measurements revealed an optimal dose of 0.4 mmol/kg. The qualitative evaluation revealed that the required qualitative assessment for clinical purposes was already reached at a dose of 0. 3 mmol/kg. No significant changes in vital signs and laboratory tests were found. No serious adverse events were observed. The combined results revealed the dose of 0.3 mmol/kg as the diagnostically adequate dose given the gradient-echo sequence and field strength used. Gadovist 1.0 has been shown to be a safe and well-tolerated contrast agent. J. Magn. Reson. Imaging 2000;12:371-380.

Adolescent↗
PubMed2000

[Progressive multifocal leukoencephalopathy in AIDS. Overview and retrospective analysis of 17 patients].

We describe retrospectively the course of 17 AIDS patients with progressive multifocal leukoencephalopathy (PML) and give a review of their clinical symptoms and survival times. The relative frequency of PML in our cohort of AIDS patients was 2.6%. The mean of CD4-positive cells was 80.5 +/- 82.5/microliter. CD4-positive cells were > 200/microliter only in one patient and increased significantly under a combination of three antiretroviral drugs whereas, with the other patients, CD4-positive cells did not increase with a maximum of two antiretroviral drugs. The mean survival time was 6.6 (1.5-20) months and correlated positively with the number of CD4-positive cells. The diagnosis of PML can be regarded as confirmed when JC-virus DNA is detectable in cerebrospinal fluid, typical changes can be seen in MRI and typical clinical symptoms occur. No effective therapy is known to date. Single case reports on therapy with cidofovir, as in one of the cases described here, showed positive results.

AIDS-Related Opportunistic Infections↗
PubMed2000

Drug-induced changes in cerebral glucose consumption in bifrontal epilepsy.

PURPOSE: Positron emission tomography (PET) using 18F-radiolabeled deoxyglucose (18F-FDG) is a sensitive procedure for detection of epileptogenic foci. Although alterations in glucose consumption are not restricted to the area of seizure generation itself, the magnitude and extent of cerebral metabolic disturbances induced by epileptic discharges can be detected. Despite two decades of epilepsy research using 18F-FDG-PET, little is known about the metabolic changes during therapy of focal epilepsy. We report on a child with frontal epilepsy with severe glucose hypometabolism that was nearly completely normalized during drug therapy. METHODS: Interictal 18F-FDG-PET was performed at the onset of epilepsy and after optimized drug therapy in a 5-year-old boy with behavioral abnormalities and repetitive seizures of frontal origin with bifrontal interictal EEG slowing for 8 weeks. Both scans were anatomically matched; initial and intratherapeutic glucose metabolism were compared. RESULTS: In accordance with the epileptogenic focus as identified by EEG and ictal/interictal perfusion single-photon emission tomography (SPECT), bifrontal hypometabolism was depicted by 18F-FDG-PET. Magnetic resonance imaging (MRI) was unremarkable. After dual-drug therapy (valproate, carbamazepine), the boy became seizure free, and his initial behavioral deficits disappeared. A control PET study after 3 months of therapy showed restored glucose consumption; the frontal EEG slowing was normalized. CONCLUSIONS: This case demonstrates that reduction of glucose metabolism in epileptogenic foci may be a result of reversible neuronal dysfunction that correlates with the electroclinical follow-up.

Anticonvulsants↗
PubMed2000

Optimized activation of the primary sensorimotor cortex for clinical functional MR imaging.

BACKGROUND AND PURPOSE: One application of functional MR imaging is to identify the primary sensorimotor cortex (M1 and S1) around the central sulcus before brain surgery. However, it has been shown that undesirable coactivation of nonprimary motor areas, such as the supplementary motor area and the premotor area, can interfere with the identification of the primary motor cortex, especially in patients with distorted anatomic landmarks. We therefore sought to design a simple functional MR imaging paradigm for selective activation of the primary sensorimotor cortex. METHODS: Different paradigms using finger tapping for motor activation were examined and compared with respect to the distribution of activated voxels in primary and nonprimary cortical areas. Studies were conducted in 14 healthy volunteers using a blood oxygen level-dependent multislice echo-planar imaging sequence. RESULTS: The most selective activation of the primary sensorimotor cortex was obtained with a paradigm combining right-sided finger tapping as the activation condition with left-sided finger tapping as the control condition. Analysis of the signal time course of primary and nonprimary areas revealed that the highly selective primary motor activation was due to it being restricted to contralateral finger movements, as opposed to the nonprimary motor areas, which were activated by ipsilateral, contralateral, and bilateral finger movements alike. CONCLUSION: When performing functional MR imaging to determine the location of the primary sensorimotor cortex, one should compare unilateral voluntary movements as the activation condition with contralateral movements as the control condition to accentuate activation of the primary motor area and to suppress undesirable coactivation of nonprimary motor areas.

Adult↗
PubMed1999

Lipoprotein (a) and genetic polymorphisms of clotting factor V, prothrombin, and methylenetetrahydrofolate reductase are risk factors of spontaneous ischemic stroke in childhood.

Ischemic stroke is a rare event in childhood. In approximately one third of cases no obvious underlying cause or disorder can be detected. We investigated the importance of genetic risk factors of venous thromboembolism in childhood or stroke in adulthood as risk factors for spontaneous ischemic stroke in children. One hundred forty-eight Caucasian infants and children (aged 0.5 to 16 years) with stroke and 296 age-matched controls from the same geographic areas as the patients were analyzed for increased lipoprotein (a) [Lp(a)] levels >30 mg/dL; for the presence of the factor V (FV) G1691A mutation, the prothrombin (PT) G20210A variant, and the TT677 genotype of methylenetetrahydrofolate reductase (MTHFR); and deficiencies of protein C, protein S, and antithrombin. The following frequencies (patients v controls), odds ratios (ORs), and confidence intervals (CIs) of single risk factors were found: Lp(a) >30 mg/dL (26.4% v 4.7%; OR/CI, 7.2/3.8 to 13.8; P <.0001), FV G1691A (20.2% v 4%; OR/CI, 6/2.97 to 12.1; P <.0001), protein C deficiency (6% v 0.67%; OR/CI, 9.5/2 to 44.6; P =.001), PT G20210A (6% v 1.3%; OR/CI, 4.7/1.4 to 15.6; P =.01), and the MTHFR TT677 genotype (23.6% v 10.4%; OR/CI, 2.4/1.53 to 4.5; P <.0001). A combination of the heterozygous FV G1691A mutation with increased Lp(a) (n = 11) or the MTHFR TT677 genotype (n = 5) was found in 10. 8% of cases, but only 0.3% of controls (OR/CI, 35.75/4.7 to 272; P <. 0001). Increased Lp (a) levels, the FV G1691A mutation, protein C deficiency, the prothrombin G20210A variant, and the MTHFR TT677 are important risk factors for spontaneous ischemic stroke in childhood.

Adolescent↗
PubMed1999

Metabolic characterization of AIDS dementia complex by spectroscopic imaging.

Prospective proton chemical shift imaging (CSI) of the brain was performed in 30 HIV- 1-seropositive patients and 11 healthy controls. Significant (P < 0.05) reductions in the N-acetyl-L-aspartate (NAA)/total creatine (Cr), and NAA/total choline (Cho) ratios and significant increases in Cho/Cr occurred in patients with 1) AIDS-defining diagnoses; 2) <200 CD4 lymphocyte counts/microl; 3) neurological evidence for an AIDS dementia complex (ADC); 4) magnetic resonance imaging (MRI) signs of cerebral atrophy. The basal ganglia and the insula were affected to approximately the same extent and without indications of spatial variations within these areas. Reduced NAA seems to indicate progressive neuronal injury or loss due to productive HIV infection in the brain and its clinical picture ADC. Spectroscopic abnormalities were, however, also observed in neurologically normal HIV patients or those with normal MRI results. Proton CSI may therefore serve as an early quantitative marker of central nervous system involvement in AIDS.

AIDS Dementia Complex↗
PubMed1999

[Cidofovir (vistide) in therapy of progressive multifocal leukoencephalopathy in AIDS. Review of the literature and report of 2 cases].

The progressive multifocal leukoencephalopathy (PML), a complication of the acquired immunodeficiency syndrome (AIDS) in 4%-5% of all cases, is an encephalitis caused by the JC papovavirus. The prognosis is very poor with a mean survival time after diagnosis of 3 to 6 months. No effective therapy is known to date. Therapeutic trials in small groups of patients with alpha-interferon, didanosine, and arabinoside were of minor success. A controlled study with cytarabine did not show any efficacy. Single case reports on a therapy with cidofovir (Vistide), an approved nucleotide-analogone in the therapy of cytomegalovirus-retinitis in AIDS-patients without renal dysfunction, showed positive results. We describe 2 more cases of a therapy of cidofovir in AIDS-associated PML. Out of 22 cases described in the literature, including these 2 cases, with a therapy of cidofovir in AIDS-associated PML, 16 patients improved under therapy, 2 remained stable, and only 4 patients still worsened fulminantly. These results indicate an additive antiviral effect of cidofovir against JC-virus. This may be used in the therapy of PML in AIDS-patients because no alternative antiviral therapy of PML is available at present. The efficacy of cidofovir for the therapy of PML is suggested by case reports. The exact mechanisms leading to an improvement under a therapy with cidofovir in the 16 cases described so far should be evaluated in a randomised, controlled study with an adequate size of cohorts.

AIDS-Related Opportunistic Infections↗
PubMed1999

Clinical applications of functional MRI at 1.0 T: motor and language studies in healthy subjects and patients.

In this article we describe clinical applications of functional MRI (fMRI) at 1.0 T. All experiments were performed on a commercially available 1.0-T system (Magnetom Impact Expert, Siemens AG, Erlangen, Germany) using a blood oxygen level-dependent (BOLD)-sensitive multi-slice EPI technique (TE 66 ms, 4 mm slice thickness, 210 mm field of view, 64 x 64 acquisition matrix). Different paradigms for localization of the motor cortex and for language lateralization were tested in healthy subjects and patients. Methodological considerations concerning the development of the paradigms are also described. In all healthy subjects, motor activation elicited BOLD signal changes in the sensorimotor cortex, permitting identification of primary motor and sensory cortical areas. Furthermore, focal activation of different cortical areas by a language task was possible in 6 of 10 subjects. Nineteen motor studies were performed in 18 patients with supratentorial lesions, in most cases prior to neurosurgical procedures. In 14 studies, fMRI results demonstrated the localization of the motor hand areas relative to the lesion. The results proved valuable for preoperative planning and contributed to therapeutical decisions. We conclude that functional MRI for clinically relevant applications, such as localization of motor and language function, is feasible even at a field strength of 1.0 T without dedicated equipment.

Adult↗
PubMed1999

Craniocervical artery dissection: MR imaging and MR angiographic findings.

Dissection of the carotid and vertebral arteries is a not so uncommon cause of stroke and has to be considered as a differential diagnosis especially in younger patients. Therapeutic and prognostic implications are different from those in extracranial atherosclerotic disease. Dissection results from hemorrhage into the vessel wall usually between the layers of the media. Digital subtraction angiography (DSA) depicts the resulting luminal compromise that may reveal some typical, but not specific, findings. The same is true for non-invasive angiographic techniques such as time-of-flight magnetic resonance angiography (MRA) and computed tomography angiography (CTA), which have shown accurate results compared with DSA. The main advantage of these techniques is the direct visualization of the vessel wall confirming the intramural hematoma. This is achieved best with MR imaging due to the high signal of blood degradation products on T1- and T2-weighted images. Therefore, MRI in combination with MRA is presently the method of choice for initial diagnosis and follow-up of craniocervical artery dissection (CCAD). In some questionable cases, CTA is a non-invasive alternative that is independent of flow phenomena.

Adolescent↗
PubMed1999

Echocontrast-enhanced ultrasound of extracranial internal carotid artery high-grade stenosis and occlusion.

BACKGROUND AND PURPOSE: Proper assessment of extracranial internal carotid artery high-grade stenosis and occlusion by extracranial color-coded duplex sonography (ECCD) is occasionally made difficult by shadowing, an unfavorable insonation angle, low flow velocity or volume, or a deep insonation depth. In these cases, echocontrast could be helpful to quantify the degree of stenosis and to diagnose occlusion. METHODS: We investigated 17 arteries with poor precontrast investigation conditions and suspected high-grade stenosis or occlusion by contrast-enhanced ECCD. RESULTS: Compared with the precontrast scans, echocontrast allowed for significantly more segments to be evaluated by pulsed Doppler sonography (P<0.001) and for longer lumen segments to be displayed on color mode (P<0.001). Because it was now possible to place the sample volume right into the jet of the stenosis, the maximal flow velocity registered increased in all patients with stenosis. CONCLUSIONS: Echocontrast-enhanced ECCD of the carotid arteries is helpful for stenosis classification in a small group of preselected patients with poor original examination conditions.

Adult↗
PubMed1998

Surgical management of intraosseous skull base tumors with aid of Operating Arm System.

Invasion of bone and critical neurovascular structures often impedes complete resection of intraosseous skull base neoplasms, and these lesions tend to recur unless all infiltrated bone is removed. Evolving experience with image guidance over the past few years indicates the potential value of neuronavigation in skull base lesions diffusely infiltrating or fixed to bone structures. We report our early experience with the Radionics Operating Arm System (OAS), specifically emphasizing its utility as an adjunct in the treatment of intraosseous skull base tumors, mainly meningiomas. In April 1995 the OAS was introduced into clinical use at the neurosurgical university clinic in Münster, Germany. Since then, the system's utility has been explored in 10 patients out of the total neuronavigation series presenting with intraosseous skull base tumors (nine females and one male, mean age 47 years; nine meningiomas, one chordoma). For navigational planning, both 3-mm computed tomography scans and a set of 3-mm fat-suppression magnetic resonance images were chosen. At least four adhesive skin markers were used for system calibration. The system was technically usable in all cases in this small series. Because of the relative immobility of the bone structures and/or the tumor, no significant deviation from the preoperative registration accuracy was noted at the end of the procedures. The main advantages were easier localization and resection of infiltrated bone, which is often not grossly identifiable, even under the microscope. Our preliminary experience with the OAS suggests that image guidance is helpful in this type of lesion, providing better anatomical orientation during surgery and delineating tumor margins and their relation to critical neurovascular structures. The problem of a possible intracranial tumor and brain shift can be neglected in these lesions. The system facilitates resection by volumetric contour information, allowing more aggressive and complete resection.

Adult↗
PubMed1998

Localized proton NMR spectroscopy in the striatum of patients with idiopathic spasmodic torticollis.

Single voxel proton spectroscopy was used to study brain metabolism in idiopathic spasmodic torticollis. Peak metabolite ratios in long echo time (135 ms) spectra were evaluated in the basal ganglia of 16 patients (29-65 years). Eight of them were untreated; the other eight were examined 4-6 weeks after administration of botulinum toxin type A. As compared with 60 control spectra, patients showed a significant, therapy-resistant decrease in N-acetyl-L-aspartate (NAA)/choline (Cho). NAA/creatine (Cr) and Cho/Cr were close to normal in the post-treatment group but significantly reduced in untreated patients. This result is consistent with the hypothesis that striatal Cr is reversibly elevated in chronic muscle stimulation. The right and left striatum were affected to the same extent.

Aspartic Acid↗
PubMed1998

[Aneurysmal hemorrhage as a complication of paracentesis].

Aneurysms of the temporal part of the carotid artery are unusually rare. The literature contains only a few previous reports dealing with hemorrhage from such malformations. In the present case massive bleeding occurred from a right-sided intrapetrous aneurym after myringotomy, which was performed as treatment for bilateral secretory otitis media. Due to the absence of any specific symptoms and the masking effect of middle ear glue preoperative identification of the aneurysm was not possible. Subsequent angiography showed the large fusiform extension of the intrapetrous aneurysm as well as multiple intracranial aneurysms. Leakage from the aneurism was closed definitively with muscle, fascia lata and a gelatin-resorcin-formalin-glue (Cardial). In order to apply the tissue patch the hypotympanic site of the aneurism was exposed using a posterior otosurgical approach. Due to extensive intracranial collateralization to the vertebral arteries bleeding persisted even after ligation of both carotid arteries. Temporary cardiac asystole was then induced to allow safe closure of the aneurysm. Following surgery the patient sustained loss of hearing in her ear and a partial peripheral facial palsy.

Aneurysm, Ruptured↗