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Biomedical subjects

E Achten

Publications and source records attributed to E Achten.

At least 55 records · Page 3Linked to original sources

Clinical and neurophysiological correlations in patients with refractory partial epilepsy and intracranial structural lesions.

Twenty patients (13 males, 7 females), who presented with refractory partial epilepsy and a CT and/or MR detected intracranial intra-axial structural lesion were admitted to the University of Gent Epilepsy Monitoring Unit. Mean duration of the epilepsy was 17 years (2-47 years). All patients were enrolled in a comprehensive presurgical protocol including neurological examination, video-scalp-EEG monitoring with prolonged interictal and ictal recording, neuropsychological assessment and positron emission tomography (PET). Intracranial EEG monitoring was performed in 5 patients in whom discrepancies between different tests were found during the non-invasive evaluation. Clinical neurological examination was normal in 16 patients; 4 patients had a mild contralateral hemiparesis. Lesions were mainly located in the temporal lobe (55%). Most patients presented with complex partial seizures (90%). Clinical seizure characteristics correlated well with the lesion location in 55% of patients. Interictal EEG showed focal epileptic activity and focal slowing in respectively 85% and 30% of patients. Interictal EEG lateralization was congruent with the side of the lesion in 17 patients (85%). Interictal EEG localization was congruent with the lobe of the lesion in 13 patients (65%). Ictal EEG lateralized correctly in 14 patients (70%) and localized correctly in 10 patients (50%). Neuropsychological assessment lateralized and localized congruently in respectively 8/17 (47%) and 7/17 (41%) of patients. Interictal PET showed focal interictal hypometabolism, congruent with the lesion, in 13/16 (81%) of patients. Intracranial EEG was congruent with the lesion location in 3 patients but non-congruent in 2 patients. All patients underwent surgical procedures: average follow-up was 14 months (6-24 months). Complete surgical removal of the lesion with free margins resulted in a more than 90% reduction of seizures without postoperative neurological deficit in 12/13 patients.

Adolescent↗

A large intracranial xanthoma in familial hypercholesterolemia.

Intracranial xanthomata occurring in patients with familial hypercholesterolemia are very rare. We present a young woman with a large intracranial xanthoma. The patient was treated for a familial hyperlipoproteinemia type IIa. MRI and morphological features are shown and discussed on reviewing the literature.

Adult↗

Sulfasalazine-associated encephalopathy in a patient with Crohn's disease.

We report a case of acute encephalopathy in a patient with Crohn's disease who had taken sulfasalazine for 1 month. The development of a toxic hepatitis and dermatitis prompted interruption of the drug. Four days later, neurological symptoms became evident. These included acute monoparesis of the left arm, the development of stupor and coma, with endorotation of both arms and a left Babinski sign. CT and magnetic resonance imaging revealed multiple lesions in the white and gray brain matter, suggesting diffuse cerebral microangiitis. All cerebrospinal fluid examinations were negative. Methylprednisolone was given intravenously. Complete clinical normalization followed. Neurotoxicity secondary to sulfasalazine has seldom been reported in the literature. We found certain similarities between this case and two previous case reports suggesting a hypersensitivity reaction to sulfasalazine or one of its metabolites. For ethical reasons, no rechallenge was performed.

Acute Disease↗

Sulfasalazine-associated encephalopathy in a patient with Crohn's disease.

We report a case of acute encephalopathy in a patient with Crohn's disease who had taken sulfasalazine for 1 month. The development of toxic hepatitis and dermatitis prompted interruption of the drug. Four days later, neurologic symptoms became evident. These included acute monoparesis of the left arm, the development of stupor and coma, with endorotation of both arms, and a left Babinski sign. CT and MR imaging revealed multiple lesions in the white and gray brain matter, suggesting diffuse cerebral microangiitis. All cerebrospinal fluid examinations were negative. Methylprednisolone was given intravenously. Complete clinical normalization followed. Neurotoxicity secondary to sulfasalazine has seldom been reported in the literature. We found certain similarities with two previous case reports suggesting a hypersensitivity reaction to sulfasalazine or one of its metabolites. For ethical reasons, no rechallenge was performed.

Adult↗

Deep cerebral venous thrombosis in thalamo-ventricular hemorrhage of the term newborn.

Unilateral thalamic bleeding with associated intraventricular hemorrhage is reported in three full-term neonates. The first presented within 48 hours from birth with early onset streptococcal meningitis, persistent pulmonary hypertension, tonic seizures and a tense fontanelle. The second presented 6 days after birth with irritability, opisthotonus, a tense fontanelle and tonic seizures. The third was admitted three days after birth with seizures and a tense fontanelle. In the latter two infants NMR and CT imaging documented thrombosed superficial and deep cerebral veins. The etiopathogenesis of intracranial venous thrombosis in the neonate is diverse: asphyxia, dehydration, polycythemia, sepsis-meningitis and difficult delivery are the main causes. In one of our patients jugular vein compression by the collar of a negative-pressure ventilation chamber probably initiated the intracranial events. More than half of the survivors sustain severe neurological impairment.

Cerebral Hemorrhage↗

Noninvasive diagnosis of superior sagittal sinus thrombosis in a neonate.

A newborn boy presented within the first day of life with moaning, anemia, and thrombocytopenia. The clinical syndrome resulted from thrombosis of the posterior part of the superior sagittal sinus due to impression at birth of the tip of the occipital squama. Both computed tomography and ultrasound scans were valuable noninvasive tools for documentation of the thrombus itself and the cerebral sequelae. Color Doppler ultrasound scan confirmed the absence and reappearance of flow in the superior sagittal sinus.

Birth Injuries↗

Nerve sheath tumors: evaluation with CT and MR imaging.

Tumors of nerves are classified into benign (schwannoma and neurofibroma) and malignant nerve sheath tumors. Schwannomas almost always occur as solitary lesions, whereas neurofibromas may occur alone or in a greater number, especially in patients with the peripheral form of von Recklinghausen's disease. Benign nerve sheath tumors often present as asymptomatic, slowly growing soft tissue masses. Although malignant nerve sheath tumors are relatively rare, a sudden increase in the size of a lesion, in particular in a patient with neurofibromatosis, should raise the suspicion of malignant change. On computed tomography (CT) and magnetic resonance imaging (MR) a benign nerve sheath tumor usually appears as a well-defined, oval, spherical or fusiform mass with smooth borders and distinct outlines, located in the subcutaneous tissue or centered at the expected anatomic location of a nerve, with displacement of adjacent soft tissues. Generally nerve sheath tumors have a low density on unenhanced CT scans. On MR they are isointense to muscle on T1-weighted images, whereas on T2-weighted images the signal intensity is high. Both on CT and MR the degree of contrast enhancement is moderate to marked and may be homogeneous or inhomogeneous. MR has become the method of choice for evaluating the anatomic location, contour, and relation of a nerve sheath tumor to adjacent neural, vascular, and muscular structures. The imaging criteria for malignant nerve sheath tumors are not specific enough to distinguish them from other malignant soft tissue tumors, so that neither CT nor MR can establish a definite diagnosis.

Adolescent↗

Elastofibroma dorsi: CT, MR and pathologic study in a new case.

As reported before elastofibroma dorsi is a rare benign tumor of elastic connective tissue with typical clinical and suggestive radiological features. We evaluated the CT and MR characteristics of this periscapular lesion in a new case, before and after contrast enhancement, and tried to determine in how far the nature and extent of the tumor can be predicted.

Back↗

Pancreatic encephalopathy. A case report and review of the literature.

Pancreatic encephalopathy is an uncommon condition found in patients with acute pancreatitis. The present report shows the interest of MRI in the diagnosis of this disorder. Patchy white matter signal abnormalities, resembling plaques seen in multiple sclerosis, may reflect the lesions that are found in the cerebral white matter of post-mortem confirmed cases.

Brain↗

31P-NMR spectroscopy and the metabolic properties of different muscle fibers.

To study the in vivo recruitment of different fiber types and their metabolic properties, 31P-nuclear magnetic resonance spectroscopy (31P-NMRS) of the human calf muscle was performed in seven normal sedentary subjects. In the exhaustive exercise protocol used, the work load was increased every minute during 5 min. This resulted in a prominent split of the Pi resonance in all subjects, indicating pH compartmentation in the muscles studied. From the chemical shift of the Pi peaks relative to phosphocreatine (PCr) at the end of the exercise, intracellular pH (pHi) averaged 6.92 +/- 0.05 (SD) in compartment 1 and 6.23 +/- 0.15 in compartment 2. The recovery of both Pi resonances after exercise could be followed easily in five of these subjects. The recovery rate of the Pi peak is a good estimate of the oxidative metabolism at the end of the exercise. A monoexponential regression analysis showed that the mean initial recovery rate S0 was 2.49 +/- 0.17%/s in compartment 1 and only 0.87 +/- 0.12%/s in compartment 2, indicating aerobic function three times higher in compartment 1 at the end of exercise. The mean relative ATP fraction dropped significantly (P less than 0.001), from 20.0 +/- 1.0% of the total 31P signal integral before exercise to 14.0 +/- 1.6% at the end of exercise. The simultaneous visualization of two compartments, in good order, one with high pHi and fast recovery and another with low pHi and slow recovery, is rationalized by the different metabolic behavior of type I and II fibers in human calf muscle in response to exhaustive exercise. This study demonstrates that 31P-NMRS is an excellent noninvasive procedure to quantify aerobic metabolism in both fiber types simultaneously.

Adenosine Triphosphate↗

An unusual case of cystic lymphangiomatosis of the spleen.

Isolated lymphangiomatosis of the spleen is rare. When present, it is usually considered to be accompanied by splenomegaly. We describe a case of cystic lymphangiomatosis in a patient with a normal-sized spleen. While ultrasound, angiography and computed tomography are considered to complement each other in reaching a preoperative diagnosis of splenic lymphangiomatosis, in the present case, magnetic resonance imaging proved to be an additional helpful non-invasive diagnostic method.

Female↗

Malignant schwannoma. A case report and review of the literature.

A rare case of a malignant schwannoma presenting as a central fracture-dislocation of the acetabulum is reported. Histological examination showed a high-grade sarcoma. A pleural metastasis was present. A local reconstructive procedure consisting of local tumor excision with an acetabular prosthetic replacement and adjunctive radiation therapy was elected for the patient, who had a short-term prognosis.

Acetabulum↗

Pre- and peroperative diagnosis of metastatic pheochromocytoma in multiple endocrine neoplasia type 2a.

A 37-year-old woman with a multiple endocrine neoplasia type 2a underwent bilateral adrenalectomy and total thyroidectomy with parathyroidectomy in 1977. The left-sided pheochromocytoma was considered to be malignant. Seven yr after the initial operation, an enhanced urinary excretion-ratio of N-methyladrenaline/adrenalin suggested the possible presence of either persistent or metastatic pheochromocytoma Iodine-123-labeled metaiodobenzylguanidine scintigraphy (I-123 MIBG) showed a hot spot in the right lung. However, repeated chest-X-rays and computed tomographic scanning of the thorax remained negative. Anatomical localization of the lesion was finally obtained with magnetic resonance imaging. The surgical removal of the small pheochromocytoma was guided by the gamma-ray emission of I-123 MIBG administered iv before the operation. This case report illustrates the usefulness of new analytical methods and of new imaging techniques in the diagnosis and management of metastatic pheochromocytoma.

Adult↗

Two motion-detection algorithms for projection-reconstruction magnetic resonance imaging: theory and experimental verification.

In this paper, projection-reconstruction (PR) magnetic resonance (MR) imaging is considered. We present two new quantitative techniques that allow to check when motion was present during a PR MR experiment. No a priori information about the motion is required since only the measured MR signals are used in the calculations. Moreover, the proposed methods can be implemented on a standard personal computer or workstation. It is experimentally shown that both methods are able to detect motion intervals with an accuracy of one repetition time.

Artifacts↗