Defining pseudoprogression in glioblastoma multiforme.

BACKGROUND AND PURPOSE: Pseudoprogression is a frequent phenomenon observed since the introduction of postoperative therapy with radiotherapy and temozolomide (RT/TMZ) in glioblastoma multiforme (GBM) patients. However, the criteria defining pseudoprogression, its incidence, the time of occurrence and its impact on therapy and outcome remain poorly defined. METHODS: The objective of this study is to compare two sets of criteria (liberal and stringent), defining pseudoprogression, in a cohort of patients treated before and after the introduction of RT/TMZ in the standard postoperative treatment. This retrospective review includes 136 unselected and consecutively treated patients with pathologically diagnosed GBM. RESULTS: Pseudoprogression was observed in 10 (12%) cases applying the stringent criteria, and in 18 (23%) patients when using the liberal criteria, in the cohort treated with RT/TMZ. Pseudoprogression was observed in only one patient treated with RT alone. The median time to pseudoprogression was 4 weeks after the end of RT. Patients with pseudoprogression had a median survival time of 28 months, compared with 12 months for patients without pseudoprogression. CONCLUSIONS: The incidence of pseudoprogression after RT/TMZ strongly depends on the applied criteria. However, regardless of the stringency of the criteria, the impact on survival remains the same.

Conservative management of complicated Rathke's cleft cyst mimicking pituitary apoplexy.

Summary: Complicated Rathke's cleft cyst (RCC) is a rare occurrence of symptomatic bleeding or growth of a previously asymptomatic (and often undiagnosed) intrasellar cyst derived from remnants of Rathke's pouch, situated on the midline between the adeno- and neurohypophysis. Symptoms may be identical to those of pituitary apoplexy: acute onset of headache, hypopituitarism, and neurological disturbances. Both syndromes may also exhibit a similar appearance of a large haemorrhagic sellar mass at initial radiological evaluation. We report on two patients who presented with headache and complete hypopituitarism. Based on the initial MRI, they were first diagnosed with pituitary apoplexy but managed conservatively with hormone therapy alone because of the absence of severe visual or neurological threat. Upon follow-up at 4 months, clinical evolution was good in both patients but their pituitary mass had not reduced in size and, after careful radiologic reviewing, was more indicative of a large midline complicated RCC. In conclusion, the diagnosis of complicated RCC is challenging because it can mimic pituitary apoplexy clinically, biologically, and radiologically. Clinicians should distinguish between the two entities using specific radiological signs or evolution of the mass at MRI if the patient does not undergo surgery. To our knowledge, we report conservative management of this rare condition for the first time, though it seems appropriate in the absence of neurological compromise or visual compression. Long-term follow-up is however mandatory. Learning points: Complicated Rathke's cleft cyst can mimic pituitary apoplexy, presenting with sudden onset of headache, hypopituitarism, and visual and neurological compromise in the most severe cases. At diagnosis, pituitary MRI may not be able to differentiate between the two entities, showing a large haemorrhagic mass inside the sella, with little or no normal pituitary tissue visible. Patients are often diagnosed with apoplexy at this stage and may undergo pituitary surgery. When surgery has not been performed initially in these patients, repeat imaging at 3-6 months is unchanged and does not show the expected involution usually seen after adenoma apoplexy. Conservative management with hormonal replacement seems a valid option in the absence of visual or neurological deficits that would require trans-sphenoidal surgery.

Unenhanced brain CT is useful to decide on further imaging in suspected venous sinus thrombosis.

AIM: To assess the value of unenhanced brain computed tomography (CT) in the diagnosis of cerebral venous sinus thrombosis (CVST). MATERIALS AND METHODS: Unenhanced brain CT images of 26 patients with proven CVST were mixed with 26 age and sex-matched images from patients without CVST. Four readers reviewed the 52 brain CT images and were asked to score the examinations for the absence or presence of CVST on a scale from 0 to 4. The mean density in the different venous sinuses was measured by one radiologist. RESULTS: The sensitivity of unenhanced brain CT for the diagnosis of CVST was 73%. There were no false-positive readings. A receiver-operating characteristic (ROC) analysis on these data resulted in an area under the curve of 0.86. Density measurements proved to be helpful, but could not detect all cases of CVST. CONCLUSION: Unenhanced brain CT is a valid initial radiological examination in the diagnosis of CVST. Due to the absence of false-positives in the present series, unenhanced CT can be used to decide whether further imaging with CT angiography or magnetic resonance angiography is required.

Symptomatic stenosis of the cavernous portion of the internal carotid artery due to an irresectable medial sphenoid wing meningioma: treatment by endovascular stent placement.

A 48-year-old woman, with right-sided proptosis and decreased visual acuity, presented with acute left sensorimotor deficit. Recent ischemia in the right posterior watershed area was found on CT and MR imaging, as well as a right-sided medial sphenoid wing meningioma causing high-grade stenotic encasement of the cavernous portion of the right internal carotid artery. Because the patient was symptomatic and complete resection of the meningioma was impossible, the stenosis was successfully treated with a balloon-expanding stent.

Cerebral ischemia after filter-protected carotid artery stenting is common and cannot be predicted by the presence of substantial amount of debris captured by the filter device.

PURPOSE: Protected carotid artery stent placement is currently under clinical evaluation as a potential alternative to carotid endarterectomy. The current study was undertaken to determine the incidence of new ischemic lesions found on diffusion-weighted MR imaging (DWI) in nonselected patients after protected carotid artery stent placement using a filter device and to determine the potential relationship between these new ischemic lesions and the presence or absence of a clear amount of debris captured by the neuroprotection filter device. MATERIALS AND METHODS: A nonrandomized cohort of 52 patients (40 men, 12 women) presenting with carotid occlusive disease underwent protected carotid artery stent placement using a filter device. DWI obtained 1 day before stent placement was compared with that obtained 1 day after stent placement. In addition, the macroscopic and microscopic analysis of debris captured by the filter device during the carotid stent placement procedure was assessed. RESULTS: Neuroprotected carotid stent placement was technically successful in all 53 procedures but was complicated by a transient ischemic attack in 3 patients (5.6%). In 22 patients (41.5%), new ischemic lesions were found on DWI, and in 21 filter devices (39.6%), a substantial amount of atheromatous plaque and/or fibrin was found. No clear relationship between the presence of debris captured by the filter device and new lesions detected by DWI was found (P = .087; odds ratio 3.067). CONCLUSION: Neuroprotected carotid artery stent placement will not avoid silent cerebral ischemia. Systematic microscopic analysis of debris captured by the filter device has no predictive value for potential cerebral ischemia after carotid artery stent placement.

Diffusion-weighted MRI in sporadic Creutzfeldt-Jakob disease.

Diffusion-weighted MRI (DWI) was used in three patients with autopsy-proven sporadic Creutzfeldt-Jakob disease (CJD) to provide a rapid noninvasive way to make this sometimes confusing diagnosis. DWI prompted the diagnosis of CJD at an early stage and appears to be particularly useful for monitoring the progression of the disease. We suggest that patients with suspected CJD and no abnormalities on T2- and proton density-weighted images may have cortical involvement on DWI.

Familial temporal lobe epilepsy with febrile seizures.

Described are the clinical, EEG, MR, and genetic characteristics of 106 members of a family with autosomal dominant temporal lobe epilepsy (TLE) and febrile seizures (FS), with 22 affected individuals. Eleven patients had a history of FS, and 10 patients had TLE. EEG showed epileptic activity in five. None had hippocampal sclerosis. There was no evidence for linkage to 13 candidate loci. This large family with autosomal dominant TLE has a distinct phenotype and shows no linkage to known candidate regions for familial partial epilepsy and FS.

Blood pressure during long-term converting-enzyme inhibition predicts the curability of renovascular hypertension by angioplasty.

Percutaneous transluminal renal angioplasty (PTRA) was performed in 28 hypertensive patients with 50% or more unilateral renal artery stenosis. Prospectively, the study compared the extent to which systolic (SBP) and diastolic (DBP) pressure during long-term converting-enzyme inhibition (CEI) and the ipsi- to contralateral renal vein renin ratio (RVR) predicted success of PTRA, defined as SBP less than 160 mmHg and DBP less than 95 mmHg. Both SBP and DBP after PTRA were positively correlated with pressure during CEI (P less than 0.001) and negatively with RVR (P less than 0.03). In multiple regression these associations were independent and remained statistically significant. In discriminant analysis, a SBP during CEI less than 160 mmHg, a DBP during CEI less than 95 mmHg, and a RVR greater than or equal to 1.5 identified with equal accuracy the success of PTRA. Furthermore, in patients with a SBP during CEI less than 160 mmHg, the demonstration of a RVR greater than or equal to 1.5 increased (P less than 0.05) the prediction of a positive outcome from 50 to 67%. In contrast, in 92% of the patients with a SBP during CEI greater than 160 mmHg, PTRA was not successful. Thus, blood pressure measurements during long-term CEI predict the curability by PTRA of renovascular hypertension and can be employed either alone or in association with the RVR.

Bilateral renal cell carcinoma diagnosed as renal abscesses.

The history of a patient with bilateral renal cell carcinoma, simulating bilateral renal abscesses is reported. Since hypernephroma can present with misleading systemic effects, all diagnostic tools concerning space-occupying lesions of the kidney must be interpreted with care before treatment. Punctures for cytology can be indicated when both kidneys are affected.

Simultaneous occurrence of developmental venous anomalies and cavernous angiomas.

PURPOSE: To study the clinical and radiologic findings in 15 patients presenting with both developmental venous anomalies and cavernous angiomas and to determine which lesions caused the acute clinical symptoms. METHODS: Lesions were infratentorial in 7 patients and supratentorial in 7 other patients. In one patient the developmental venous anomaly was infratentorial and the cavernous angioma supratentorial. In all 15 patients clinical examination and CT were performed. In 10 patients MR was performed at the time of the initial CT scan. In 5 patients only late MR is available. RESULTS: Acute clinical signs were present in 9 patients (epilepsy, hemiplegia, meningeal signs, cranial nerve deficit). On CT the cavernous angioma was missed in 9 patients, in 6 patients because of acute hemorrhage. On MR the cavernous angioma was missed in 1 of 2 cases with acute hemorrhage but seen in all other patients. On repeat MR all cavernous angiomas were correctly identified. On CT, 11 developmental venous anomalies were seen. On MR all developmental venous anomalies were seen. CONCLUSIONS: The frequent association of developmental venous anomalies and cavernous angiomas is confirmed. MR is superior to CT in the detection of both cavernous angiomas and developmental venous anomalies. Furthermore our data support the hypothesis that cavernous angiomas and not the developmental venous anomalies cause the acute clinical symptoms because of hemorrhage.

Gyriform calcifications in tuberous sclerosis simulating the appearance of Sturge-Weber disease.

Two cases of tuberous sclerosis are presented. Extensive superficial occipital calcifications were found as classically described in Sturge-Weber syndrome. Other radiologic signs of tuberous sclerosis, such as subependymal calcifications in both patients and surgically proved giant cell astrocytoma in one patient, were present. At pathologic examination, the calcifications appeared to be located in extensive cortical tubers.

Orbital fat edema in anorexia nervosa: a reversible finding.

Orbital fat edema was found in a patient with long-standing severe anorexia nervosa. The changes disappeared after the patient gained weight. The underlying mechanisms remains unexplained, but the changes most likely coincide with the disappearance of fat tissue and the appearance of edema following disturbance of the electrolyte/fluid balance.

Endovascular treatment of a ruptured paraclinoid aneurysm of the carotid syphon achieved using endovascular stent and endosaccular coil placement.

We herein report a case of a ruptured superior hypophyseal aneurysm of the left supraclinoid carotid artery that could not be treated with a Guglielmi detachable coil (GDC), even in combination with a supporting nondetachable balloon. After an unsuccessful attempt at surgical clipping, treatment consisted of the placement of a stent over the neck of the aneurysm, advancement of a microcatheter through the stent mesh, and endosaccular embolization with a GDC. The late clinical outcome was excellent.

Lyme disease in childhood presenting as primary leptomeningeal enhancement without parenchymal findings on MR.

We report the MR appearance of a rare case of Lyme disease presenting as diffuse leptomeningeal enhancement in the absence of parenchymal lesions. In the appropriate clinical setting, one should consider Lyme disease in the differential diagnosis of meningeal enhancement.

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.

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.

The radiological differentiation of acoustic neurinoma and meningioma occurring together in the cerebellopontine angle.

A patient with right hearing loss, in whom computed tomographic scanning demonstrated a mass in the right cerebellopontine angle with widening of and extension into the internal auditory canal, but with important posterior extension and broad implantation on the surface of the petrous bone, is reported. On both T2-weighted and gadolinium-enhanced T1-weighted magnetic resonance images, there were clearly two separate tumoral lesions: an acoustic neurinoma extending into the internal auditory canal and a meningioma with broad implantation on the petrous apex. These findings were confirmed at surgery.