Search PubMed⌕ Search

Biomedical subjects

F Van Calenbergh

Publications and source records attributed to F Van Calenbergh.

51 records · Page 3Linked to original sources

Intracerebral primitive neuro-ectodermal tumor (PNET).

A case of intracerebral primitive neuro-ectodermal tumor (PNET) is presented. PNETs are rare, undifferentiated neoplasms occurring primarily in children and young adults. These tumors exhibit a highly malignant behaviour with a tendency to disseminate along the cerebrospinal fluid (CSF) pathways. Preoperative diagnosis is difficult, owing to the non-specific CT and MR appearances and to the rarity of this tumor. Our patient was 33 years old, which is uncommon. CT findings initially suggested an intracerebral hematoma. Later on, CT and MR findings were specific for a brain tumor and showed a solid, non-calcified invasive mass, with poor perilesional edema.

Adult↗

Isodense subdural haematomas on CT:MRI findings.

MRI findings are described in two patients with subdural haematomas isodense on CT. In one patient, admitted 6 weeks after trauma, a chronic subdural haematoma showed extreme hypointensity on T2-weighted images, suggesting acute trauma, and therefore acute rebleeding. In the second patient with severe anaemia, an acute subdural haematoma was hyperintense on T2-weighted images, suggesting chronic trauma; this may be explained by the low haematocrit and a possible mixture of blood with cerebrospinal fluid. The MRI features of subdural haematomas and hygromas have to be kept in mind, in order not to misjudge the age of the haematoma.

Female↗

Intraspinal juxta-facet cysts: a case of bilateral ganglion cysts.

Juxta-facet cysts are relatively uncommon intraspinal lesions, causing radiculopathy, neurogenic claudication or myelopathy. To the best of our knowledge, only 4 cases of bilateral synovial or ganglioncysts were described. We report the 5th case of bilateral ganglioncysts of the lumbar spine. Generally, juxta-facet cysts should be differentiated from other intraspinal lesions, such as herniated discs, meningiomas and neurinomas. Correct preoperative diagnosis is necessary for adequate treatment, namely the (microscopic) resection of the cyst. After adequate treatment, complete recovery may be expected.

Aged↗

Syringomyelia: a retrospective study Part II: Diagnostic and therapeutic approach.

In a retrospective study of 62 cases of syringomyelia, spanning thirteen years, we investigated the diagnostic value of the different imaging techniques, and the outcome of the several forms of therapy. Magnetic resonance imaging appears to be the examination of choice, being most informative and least invasive. When surgical treatment is indicated, syringoperitoneal shunting will stabilize or improve the condition in a substantial number of cases. Indications for the other surgical procedures are discussed.

Adolescent↗

Syringomyelia: a retrospective study. Part I: Clinical features.

We performed a retrospective study of 62 patients with syringomyelia. Most noteworthy among the clinical features in our patient population are the following: segmental sensory disturbances are usually less restrictive than the classical thermoanalgesia, pain is a presenting symptom in almost 50% of cases, and skeletal abnormalities of the "status dysraphicus" are very common. The different hypotheses about the pathogenesis are also discussed.

Adolescent↗

Diagnosis of foraminal and extraforaminal lumbar disk herniation.

Thanks to the more systematical use of CT scan, more and more foraminal and extraforaminal disk herniations are discovered. Some symptoms and signs can be suggestive. Association of negative myelography with important radicular signs should receive special attention. The extremely lateral herniation can be managed easiest and safest by a combined approach, both interlaminar paramedian and lateral to the facet joint, which should be preserved.

Acute Disease↗

[Pericerebral collections. Analysis of neuroradiologic and radionuclide tests and therapeutic results].

The authors retrospectively studied 32 neonates with macrocrania associated with a pericerebral collection. Differential diagnosis was made between external communicating hydrocephalus, atypical communicating hydrocephalus, subdural hygroma and local cerebral atrophy by means of CT scan, isotope cisternography, and isotope brain scintigraphy. Especially the two last examinations are of great interest. The most important arguments in favour of operation were a rapidly increasing and uncontrolled head circumference graph and a deterioration of the psychomotor development. In this regard, 13 out of 25 patients with external communicating hydrocephalus were operated upon (lumbo-peritoneal shunt). The analysis of the results reveals that rapidly increasing macrocrania is a good operative indication and gives excellent results but psychomotor deterioration turned into normal evolution only in 14% of the operated cases. Evacuation of a subdural hydroma first by external and followed later on by internal drainage normalizes the clinical picture.

Atrophy↗

Velocity discrimination in central and peripheral visual field.

Just-noticeable differences (jnd's) in velocity were measured as a function of reference velocity for central and peripheral vision. The velocity discrimination curves plotting jnd's in velocity, expressed as Weber fractions, as a function of reference velocity were U shaped at all eccentricities. Under almost every stimulus condition the increase in jnd in velocity with increasing eccentricity was significantly larger at low reference velocities than at high reference velocities. Consequently the shift toward higher velocities with increasing eccentricity was much clearer for the lower end of the velocity-discrimination curve than for the upper end. These results are in agreement with the predictions derived from the response characteristics of velocity-tuned cells. Control experiments involving direction discrimination have shown that the impossibility of making fine velocity judgments at high speeds is due not to too weak a contrast for the stimulus motion to be visible but to a limitation in the neural apparatus analyzing velocity.

Adult↗

Risk analysis of thrombo-embolic and recurrent bleeding events in the management of intracranial haemorrhage due to oral anticoagulation.

PURPOSES: Intracranial haemorrhage (ICH) is a rare but potentially devastating complication of oral anticoagulants (OAC). This raises the difficult clinical choice between either permanent cessation of OAC, or continuing OAC and if so, when to restart. To make this choice, one needs to balance the thrombo-embolic risk after cessation of OAC against the risk of recurrent intracranial haemorrhage when OAC are restarted. There are few published data to base this difficult clinical decision on. METHODS: We present an observational study of a consecutive series of 108 patients, collected prospectively and admitted to our department, with an OAC-related intracranial haemorrhage, in whom we assessed the thrombotic event rate and the recurrent intracranial bleeding rate during follow-up. RESULTS: In the 25 patients in whom OAC were reinstituted no new thrombo-embolic events occurred (0/506 unprotected patient-days). In the group of patients in whom OAC were not restarted (n = 81), the thrombo-embolic event rate was 8/11590 unprotected patient-days, of which only 2 were cerebrovascular thrombo-embolisms. The overall risk of a thrombo-embolic complication can be estimated to be 0.66 events/1000 patient-days at risk (95% exact confidence limits of 0.3 to 1.3 events/1000 patient-days at risk). In three patients the thrombo-embolic event was fatal. We saw recurrent intracranial bleeding in eight patients, 2 of which were fatal. Seven of these occurred before the restarting of the OAC. CONCLUSIONS: In OAC-related intracranial haemorrhages, OAC can be stopped safely for a considerable period, with a very low overall thrombotic event rate. The recurrent bleeding risk after restarting OAC is low. Recurrent bleeding mostly occurred before restarting OAC and is probably caused by insufficient or unsustained correction of the initial coagulation deficit. Immediate reversal of anticoagulation provides the patient with the best possible treatment options including surgery. OAC-related intracranial haemorrhages can therefore be actively treated.

Administration, Oral↗

Thickening of dura surrounding meningiomas: MR features.

Thickening of the dura in continuity with a convexity meningioma was noted on T1-weighted magnetic resonance (MR) images in seven patients. In five cases the corresponding CT image of the lesions was typical of meningioma. In two other cases the CT image of the lesions was atypical, owing to cyst formation in one and extensive edema in the other. After intravenous injection of paramagnetic contrast medium in four patients, the thickened dura demonstrated contrast enhancement at a variable distance from the tumor. In three patients the thickened dura was confirmed surgically. Pathology, available in one case, showed the thickened dura to correspond to tumoral extension within or around the dura. Magnetic resonance demonstration of thickening of the dura in continuity with a mass at the cerebral convexity may prove to be of importance in the differentiation of atypical lesions on CT and MR, especially with lower field magnets. Moreover, it could provide useful information to the neurosurgeon for more complete resection of the tumor.

Aged↗

Localized 1H NMR spectroscopy in fifty cases of newly diagnosed intracranial tumors.

Fifty patients with newly diagnosed, untreated intracranial tumors were examined with 1H nuclear magnetic resonance single-volume spectroscopy (MRS) using a 1.5 T whole-body MR system. Prior to the MRS, contrast enhanced MR and/or CT imaging studies were carried out. Histological verification was obtained in all patients except one. All tumor spectra revealed distinct abnormalities as compared with the normal brain spectra. Although most meningiomas showed a rather characteristic spectral pattern, generally features specific for the various tumor types were not observed. For instance, though a strong lactic acid signal was seen in most malignant tumors, this signal was also evident in five benign neoplasms.

Adult↗

Prominent dural enhancement adjacent to nonmeningiomatous malignant lesions on contrast-enhanced MR images.

Prominent dural enhancement was noted in 10 (16%) of 61 superficial malignant intracranial tumors studied with contrast-enhanced MR imaging during a 2-year period. Included were six glioblastomas, three parenchymal metastases, and one case of dural metastasis. Seven patients had surgery. In four, there was extensive leptomeningeal invasion in the center of the lesion. In two of these lesions there was firm attachment of the center of the tumor to the dura, but without dural invasion despite extensive external carotid artery supply to the tumor in one case. In two cases the overlying dura was normal, and there was no leptomeningeal tumoral invasion. In the case of dural metastasis, huge nodular lesions were present along the inner aspect of the dura. In none of the cases did prominent dural enhancement adjacent to the tumor correspond with tumoral invasion or extension to the dura. Prominent dural enhancement on contrast-enhanced MR images appears to be much less frequent in malignant tumor than in meningioma, where it is seen in up to 60% of the cases. We believe this finding is more likely to represent reactive changes of the dura than tumoral invasion.

Brain Neoplasms↗

CT and MR in infants with pericerebral collections and macrocephaly: benign enlargement of the subarachnoid spaces versus subdural collections.

PURPOSE: To compare CT and MR in the differentiation of benign enlargement of the subarachnoid spaces and subdural collections in infants with macrocephaly. METHODS: MR was performed in 19 infants with macrocephaly, showing bifrontal enlargement of the subarachnoid spaces on CT. RESULTS: In 11 patients, a single fluid layer could be distinguished on MR of the pericerebral collections, suggesting benign enlargement of the subarachnoid spaces. In eight patients, two separate layers were clearly differentiated, an outer layer that was hyperintense on all sequences and an inner layer with the same intensity as the cerebrospinal fluid. This indicated the presence of subdural collections. These collections were mainly frontal in six and extended over the entire hemisphere in two patients. On CT, these separate lesions were seen only in three patients and missed in three others. In two final patients, CT findings were equivocal with evidence of membrane formation within the hypodense collections. In seven patients with a subdural collection, subdural-external drainage was performed. In three patients, the collection was hemorrhagic. The protein content of the fluid showed a mean of 1381.7 +/- 785.6 mg/dL. The MR and surgical findings of a subdural collection correlated with the absence of a family history of macrocrania, an age under 5 months, and acute clinical signs of vomiting, somnolence, and hypotonia. CONCLUSION: MR appears essential in the differential diagnosis between benign enlargement of the subarachnoid spaces and subdural collections in infants.

Brain Diseases↗