Biomedical subjects

T Yousry

Publications and source records attributed to T Yousry.

33 records · Page 2Linked to original sources

PubMed1996

MRI detection of epidural spinal abscesses at noncontiguous sites.

We report the cases of two patients with the very uncommon clinical finding of two noncontiguous spinal epidural abscesses, which were located in the cervical and lumbar spine. In each case the diagnosis of the second spinal abscess was made by MRI only after the appearance of a new neurological deficit. Decompressive spinal surgery and intravenous antibiotic therapy led to complete recovery in one patient; the other patient was moderately disabled. As epidural spinal abscesses can occur at noncontiguous sites, MRI of the entire spine may be necessary in selected cases.

Abscess↗

PubMed1996

Multiple sclerosis: prospective analysis of TNF-alpha and 55 kDa TNF receptor in CSF and serum in correlation with clinical and MRI activity.

The possibility of antagonizing tumor necrosis factor-alpha (TNF-alpha) in vivo with antibodies or soluble TNF receptor has focused much interest on the role of this cytokine in the natural course of MS. We studied nine patients prospectively and serially for one year (14 time points, 131 observations). TNF-alpha and the 55 kDa soluble TNF receptor were measured every 4 weeks in the serum and at defined time points in the CSF. Each value was correlated to clinical symptoms and to MRI measurements obtained on the same day. All patients with relapsing-remitting disease showed periodic increases of TNF concentrations. Overall, the association between serum TNF-alpha levels and bursts of Gd-DTPA enhancement on cranial MRI was not sufficiently tight to reach statistical significance. However, serum TNF levels > 50 pg/ml and measurable CSF levels were always associated with Gd-DTPA enhancing MRI lesions. Isolated high serum TNF peaks were noted during episodes of infection, hay fever or psychic stress. After treatment with glucocorticoids, TNF levels were suppressed for several months, whereas new Gd-DTPA enhancing lesions continued to appear. The concentrations of the soluble 55 kDa TNF receptor did not show marked fluctuations. These results are consistent with an active role of TNF-alpha in MS during periods of disease activity and provide further support for the clinical evaluation of anti-TNF therapies.

Adult↗

PubMed1996

Quantitative assessment of MRI lesion load in multiple sclerosis. A comparison of conventional spin-echo with fast fluid-attenuated inversion recovery.

In this study, we compared a fast fluid-attenuated inversion recovery (fast-FLAIR) sequence to conventional spin-echo (CSE) in the evaluation of brain MRI lesion loads of seven patients with clinically definite multiple sclerosis. Interleaved CSE (3000/20, 5 mm contiguous axial slices) and fast-FLAIR (9000/150/2200, 5 mm contiguous axial slices) sequences were performed on a 1.0 T machine. Lesions were counted consensually by two observers and then segmented independently by two other observers using a local thresholding technique, with subsequent manual editing in the case of poorly defined lesions. Four hundred and two lesions were detected in at least one of the two sequences: 128 were seen only on fast-FLAIR, 17 only on CSE. Forty-one lesions were larger on fast-FLAIR, while no lesion was considered larger on CSE. The numbers of periventricular (P = 0.05), cortical/subcortical (P = 0.02) and discrete (P = 0.05) lesions detected using fast-FLAIR were higher than those detected using CSE. The median lesion load was 7185 mm3 on CSE and 8418 mm3 on the fast-FLAIR, the average being 18% (range = 11.6-29%) higher on the fast-FLAIR images. Lesion contrast ratio was higher for lesions on the fast-FLAIR than on the CSE sequence (P < 0.0001). The percentages of poorly defined lesions which needed manual editing after the local thresholding technique was applied and the total time needed for the measurements were lower (P < 0.001) when fast-FLAIR images were used compared with CSE. This resulted in a reduced inter-rater coefficient of variation in measuring lesion volumes. Our data indicate that fast-FLAIR sequences are more sensitive than CSE in detecting multiple sclerosis lesion burden and that fast-FLAIR is a promising technique for natural history studies and clinical trials in multiple sclerosis.

Adult↗

PubMed1996

Reversible encephalopathy with cerebral vasospasm in a Guillain-Barré syndrome patient treated with intravenous immunoglobulin.

We report a patient with a reversible multifocal encephalopathy that developed 3 days after completion of treatment with intravenous immunoglobulin for Guillain-Barré syndrome. Magnetic resonance imaging showed reversible bioccipital white matter changes, and transcranial Doppler demonstrated transiently increased flow rates in all major cerebral arteries. We conclude that intravenous immunoglobulin therapy caused cerebral arterial vasospasm and a reversible encephalopathy.

Adult↗

PubMed1996

Comparison of triple dose versus standard dose gadolinium-DTPA for detection of MRI enhancing lesions in patients with MS.

We studied whether a triple dose of gadolinium-DTPA alone or in combination with delayed scanning increases the sensitivity of brain MRI for detecting enhancing lesions in patients with MS. We obtained T1-weighted brain MRI scans in two sessions for 22 patients with clinically definite MS. In the first session, we obtained one scan 5 to 7 minutes after the injection of 0.1 mmol/kg gadolinium-DTPA (standard dose). In the second session, 6 to 24 hours later, we obtained one scan before the two scans 5 to 7 minutes (for all patients) and one hour (for 11 patients) after the injection of 0.3 mmol/kg gadolinium-DTPA (triple dose). We detected 83 enhancing lesions in 14 patients when the standard dose of gadolinium-DTPA was used. The numbers of enhancing lesions increased to 138 (average increase 66%; p = 0.001) and the numbers of patients with such lesions to 18 (increase 28%) when we used the triple dose of gadolinium-DTPA. In addition, the total area per patient occupied by such lesions was greater (p < 0.0001) and lesion signal intensity higher (p = 0.0001) on the triple-dose scans than the standard-dose scans. There was an increase in the number of large enhancing lesions (p = 0.03) in the scans obtained 1 hour after the injection of the triple dose of gadolinium-DTPA. These data indicate that in patients with MS, a triple dose of gadolinium-DTPA can reveal many more enhancing lesions, which also appear larger. This suggests that the pathologic nature of "active" lesions in MS is heterogeneous, which might have impact on planning clinical trials.

Contrast Media↗

PubMed1995

Comparison of triple dose versus standard dose gadolinium-DTPA for detection of MRI enhancing lesions in patients with primary progressive multiple sclerosis.

This study was performed to evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) increases the sensitivity of brain MRI for detecting enhancing lesions in patients with primary progressive multiple sclerosis (PPMS). T1 weighted brain MRI was obtained for 10 patients with PPMS in two sessions. In the first session, one scan was obtained five to seven minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, one scan before and two scans five to seven minutes and one hour after the injection of 0.3 mmol/kg Gd-DTPA (triple dose) were obtained. Four enhancing lesions were detected in two patients when the standard dose of Gd-DTPA was used. The numbers of enhancing lesions increased to 13 and the numbers of patients with such lesions to five when the triple dose of Gd-DTPA was used and to 14 and six in the one hour delayed scans. The mean contrast ratio for enhancing lesions detected with the triple dose of Gd-DTPA was higher than those for lesions present in both the standard dose (P < 0.0009) and the one hour delayed scans (P = 0.04). These data indicate that with a triple dose of Gd-DTPA many more enhancing lesions can be detected in patients with PPMS. This is important both for planning clinical trials and for detecting the presence of inflammation in vivo in the lesions of such patients.

Adult↗

PubMed1995

Rotational vertigo in embolic stroke of the vestibular and auditory cortices.

We describe the unique case of a woman with embolic infarction within the right middle cerebral artery territory who had nonepileptic rotational vertigo, nausea, and unsteady gait that gradually resolved within a week. A well-demarcated lesion of the posterior insula (homologous to parieto-insular vestibular cortex in monkeys) was probably the cause. This is supported by a contraversive tilt of perceived vertical and by involvement of the adjacent auditory (Heschl's) cortex. Dipole source analysis of late auditory evoked potentials revealed a decreased amplitude of a dipole source in the right insular cortex, whereas two other dipoles situated in the temporal lobe showed symmetric activity.

Acoustic Stimulation↗

PubMed1995

[The motor hand area. Noninvasive detection with functional MRI and surgical validation with cortical stimulation].

In this study, activation of cortical sites by specific motor tasks (opening and closing of the hand) was examined by fMRI utilizing the blood-oxygen-level-dependent (BOLD) technique. fMRI was employed in five volunteers and in six patients with tumors in the vicinity of the central region. In the patients, the fMRI data and intraoperative cortical mapping were compared. Our results indicate good correlation of these two methods and that there are no significant differences in the localization of the motor hand area.

Adult↗

PubMed1995

[Therapy of cerebral aneurysms and arteriovenous vascular malformations in hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease)].

Little is known about the course of cerebral aneurysms in hereditary hemorrhagic teleangiectasia (Rendu-Osler-Weber's disease). Thus, therapeutic decisions are often difficult. For the first time, we report the successful embolization of an arteriovenous fistula and multiple aneurysms of the posterior inferior cerebellar artery (PICA) of a patient with Rendu-Osler-Weber's disease after subarachnoid hemorrhage. Two years later she suffered another severe intracranial hemorrhage. Angiography revealed an aneurysm in the same artery (PICA), which spontaneously disappeared within 2 months. Spontaneous regression of aneurysms in Rendu-Osler-Weber's disease has not been reported before.

Cerebellum↗

PubMed1993

Diagnosis and results of different treatment regimens in patients with spinal abscesses.

Bacterial abscesses involving the spinal canal are associated with a high morbidity and mortality. Most frequently, these lesions are found in the epidural, rarely in the subdural space. In this report, our clinical material consists of a series of 16 patients treated during the last seven years. The clinical presentation included local neurological signs (back pain, para-/tetraparesis, bladder dysfunction), disturbances of consciousness (ranging from drowsiness to deep coma) and general inflammatory signs (meningism, fever). All patients presented with risk factors (septic foci, chronic diseases, and iatrogenic causes). Laboratory investigations revealed typically pathological blood sedimentation rate, leucocytosis and CSF-pleocytosis. Radiologically, the diagnosis was confirmed by myelography, CT and preferably MRI. The abscesses were located epidurally in 14 and subdurally in 2 cases. The surgical treatment included laminectomy, or multiple flavectomies in extensive lesions. Drainage systems (either simple silicon outflow drains or suction-/irrigation systems) were installed in all cases, as well as antibiotic treatment. Results of treatment: Following an observation period of 0.5-6 years, we found complete recovery in six (38%) cases, six (38%) others were mildly disabled and four (25%) patients died. Focussing on the results of the two different drainage systems, we found a statistically significant superiority of the inflow-/outflow system. Complications included mandatory re-exploration, post-inflammatory hydrocephalus, syringomyelia, spinal instability, surgical treatment of peripheral septic foci and therapy resistant septicaemia. In conclusion, we propose that spinal epi- or subdural abscesses require surgical evacuation, using a suction-/irrigation drainage system, as well as antibiotic and intensive care treatment.

Abscess↗

PubMed1991

Role of magnetic resonance imaging in the radiological management of musculoskeletal tumors.

The treatment of bone tumors has developed from amputation surgery to refined methods of therapy in the last 20 years. Limb-preserving operations in particular require exact documentation of the intra- and extraosseous extent of the tumors. Our clinical study showed that magnetic resonance imaging (MRI) is equal to or even superior to computed tomography (CT) in regard to the most important radiological criteria. For this reason, MRI can be considered of great value in the radiological management of bone tumors. While CT is in most cases inferior to MRI, there are still special cases which require angiography.

Adult↗

PubMed1989

[Magnetic resonance tomography imaging of Botallo's duct--a case report].

In a female patient suffering from renal insufficiency in whom angiography could not be performed, it was possible to confirm the diagnosis of a ductus arteriosus (Botallo's duct) by magnetic resonance imaging. The present case report shows that it is possible to visualise this congenital heart disease by MRI. This can be of importance especially if angiography cannot be performed (as in this case) because of renal insufficiency or because of contrast medium allergy.

Adult↗

PubMed1989

[Magnetic resonance tomographic studies of stress fractures].

Stress fractures can represent a diagnostic problem especially in their differentiation from bone tumours. 6 patients with 7 lesions were examined. MRI visualised the stress fractures and established the diagnosis of stress fracture vs. tumour in 6 cases. In the seventh, biopsy having been performed, a tumour was ruled out. MRI is more sensitive than radiography in the detection of stress fractures, showing the characteristic changes earlier. MRI, being a very sensitive method in the diagnosis of stress fractures and a reliable one in their differentiation from bone tumours, can be applied in cases of unusual clinical course and difficult radiological diagnosis prior to biopsy.

Adolescent↗

PubMed1988

[Clinical use of gradient echo sequences of longer repetition times].

Studies designed to optimise image contrasts of gradient echo sequences showed, that especially repetition times between 250 and 500 ms in combination with adequate echo times and flip angles provide new image contrasts. The clinical purpose of gradient echo sequences with longer TR was systematically evaluated in 450 patients. A major advantage of GE sequences was the low signal intensity of fat and bone tissue. On the other hand different pathologic changes showed a high signal intensity in comparison to T2 weighted spin echo sequences as well. With the possibility of multiple slices GE sequences were of outstanding diagnostic value especially in MR of soft tissue and of the musculoskeletal system. T2 weighted SE sequences provided no additional informations and could therefore be omitted in a great number of examinations.

Abdomen↗

PubMedDate not supplied

Bilateral loss of eighth nerve function as the only clinical sign of vertebrobasilar dolichoectasia.

The case of a 55-year-old female is presented, in whom first a loss of the vestibular and hearing function on the left side occurred with sudden onset, and 3 days later an additional loss of functions on the right side occurred. No other neurological symptoms were present. Angiography and MRI scan revealed vertebrobasilar dolichoectasia with a thrombus attached to the wall of the basilar artery. Anticoagulative therapy improved hearing function on the right side sufficiently to allow conversation. Vestibular organs remained unresponsive to caloric irrigation. This bilateral loss of eighth nerve function is discussed as a rare case of bilateral ischemia of the labyrinthine artery due to basilar dolichoectasia.

Aneurysm↗