Kaposiform hemangioendothelioma arising from the internal auditory canal

Kaposiform hemangioendothelioma is a rare vascular tumor and locally aggressive endothelial-derived spindle cell neoplasm, which occurs almost exclusively in infants and adolescents. Radiologically, hemangioendothelioma, including Kaposiform hemangioendothelioma, is seen as a highly vascularized well-enhancing tumor, but no characteristic findings differentiate Kaposiform hemangioendothelioma from other soft-tissue tumors, particularly when the tumor is too small to have any locally aggressive features or identifiable large vessels. We present a case of Kaposiform hemangioendothelioma in the internal auditory canal that had no differential features on initial MR images and rapidly grew into a huge mass in a few months.

Clinical analysis of vertebrobasilar dissection

BACKGROUND

The natural history of vertebrobasilar artery dissection (VAD) is not fully known. The purpose of this study was to review the clinical outcome of the patients with VAD, then to propose an appropriate management strategy for VAD.

METHOD

From 1992 to 2004, 35 VAD patients admitted to our institutes were retrospectively reviewed. There were 28 men and 7 women, whose age ranged from 4 to 67 years with a mean age of 44 years. Angiography was assessed to document the shape, and location of the dissecting aneurysm with respect to the posterior inferior cerebellar artery (PICA). A modified Rankin score was assigned for functional outcome. The functional outcome scores were analyzed according to the patient's age, gender, hypertension history, the pattern of initial manifestation, angiographic shape of VAD, angiographic location of VAD, treatment modality.

FINDINGS

There was no statistically significant difference between the functional outcome with age, gender, trauma history and past medical history of hypertension. Of 35 patients, 22 presented with SAH, 11 with ischemic symptoms and 2 were incidentally detected. The patients without SAH had a better functional outcome than those with SAH (p = 0.029). There was statistical significance between Hunt-Hess (H-H) grade and clinical outcome (p = 0.032). The shape and location of VAD was not significantly related to the functional outcome (p = 0.294, 0.840). But all the cases of rebleeding and mortality (except one case with initially poor H-H grade) developed exclusively in patients with aneurysms. There was no statistically significant correlation between the treatment modality and the outcome (p = 0.691).

CONCLUSION

The VAD patients with SAH would be recommended to be managed by either surgical or endovascular treatment, but those without SAH, could be managed conservatively with antiplatelet therapy and/or anticoagulation.

Neurologic aspects of infections in international travelers

BACKGROUND

As international travel for business and pleasure becomes part of contemporary lifestyle, the clinician today is confronted with an increasing number of travelers returning ill with unfamiliar syndromes. The physician will encounter a myriad of patients with exotic infections, emerging infectious diseases, or resurgent Old-World infections.

REVIEW SUMMARY

This review article will discuss salient points of important infectious diseases associated with overseas travel, provide a syndromic approach to the traveler who returns with neurologic manifestations, and list resources for additional diagnostic, therapeutic, and preventive information.

CONCLUSIONS

As many of infections acquired in other countries can directly or indirectly affect the nervous system, the care of the ill traveler often falls into the hands of neurologists. The contemporary neurologist should therefore be knowledgeable of the clinical manifestations, potential complications, and appropriate management of region-specific infections.

Anatomical and clinical outcomes after endovascular treatment for unruptured cerebral aneurysms. A single-center experience

SUMMARY

To describe the immediate and follow-up anatomical outcomes as well as procedure-related morbidity after endovascular procedures for unruptured cerebral aneurysms, we reviewed 68 patients with 78 unruptured aneurysms treated with detachable coils from may 1996 to february 2002. Angiograms were retrospectively reviewed for the nature of the aneurysms and the degree of therapeutic obliteration. Periprocedural complications, immediate clinical outcome and longterm neurological status were analyzed. Immediate anatomical outcomes were complete in 35 aneurysms (45%); residual neck in 24 (31%), partial contrast filling in 17 (22%), and failed embolization in two (2%). Of 27 aneurysms with follow-up angiography, 12 of the 13 aneurysms that were completely occluded in the initial treatment were still completely occluded at the end of a mean follow-up period of 17 months. Periprocedural complications were thromboembolic (n=6), haemorrhagic (n=3), coil protrusion (n=7) and other unrelated complications (n=3). Only two patients, with thromboembolic complications were moderately disabled with permanent neurological deficits in immediate clinical outcome, and their condition improved to independent in 1.5 and three months each. Small aneurysms and posterior circulation location showed more protective immediate results than aneurysms of large and anterior circulation after endovascular treatment (p values: 0.01 and 0.02). Our experiences of endovascular treatment for unruptured cerebral aneurysms were comparable to the results of recent series. Endovascular treatment for small posteriorly located aneurysms produced significantly better results than for large anteriorly located lesions.

PC-Based 3D Reconstruction of MR Angiography in Evaluation of Intracranial Aneurysms. The Value of Pre-Treatment Planning for Embolization and Post-Treatment Follow-up

SUMMARY

In this study, we present our experiences of personal computer-based 3D reconstructions of MRA for pre-treatment planning and post-treatment follow-up for cerebral aneurysms. Twentynine ruptured or unruptured intracranial aneurysm patients with 36 intracranial aneurysms, who underwent embolization and pretreatment and/or follow up 3D MRA were included in this study. All 29 patients were examined by DSA and MRA before (18 patients, 24 aneurysms) and/or after embolization (16 patients, 17 aneurysms). The MRA source images were transported to a personal computer in DICOM format for viewing, post-processing, and 3D reconstruction. DSA and PC based SSD 3D MRA equally well demonstrated most aneurysms before embolization (17 patients, 22 aneurysms). The depiction of aneurysm morphology, neck evaluation and branch vessel interpretation were much easier on 3D MRA, which has the ability to manipulate images in real time. When the vascular anatomy was complicated by another vascular system, the anterior or posterior circulations were separately reconstructed easily by using PC based reconstruction software. The 3D MRA also well demonstrated post-embolization recurrence or remnant aneurysmal cavities. In one giant aneurysm, the 3D MRA was unable to show the entire aneurysmal sac due to a blood flow saturation effect, but this was resolved by additional contrast material injection. PC-based 3D MRA proved to be a useful tool for the pretreatment planning of embolization procedures and for follow up after treatment in the case of cerebral aneurysms.

Bioterrorism and the nervous system

Recent events of war, terrorist attacks, and mail-borne anthrax exposure have produced increasing awareness of potential bioterrorism attacks in the United States and other parts of the world. Physicians and healthcare personnel play a key role in identifying potential bioterrorist attacks. Early recognition and preparedness for bioterrorism-associated illnesses is especially important for neurologists because most bioterrorism agents can directly or indirectly affect the nervous system. This article reviews the neurologic manifestations, diagnosis, and treatments of syndromes caused by potential bioterrorism agents, as well as the potential side effects of vaccines against some of these agents.

Procedure-related haemorrhage in embolisation of intracranial aneurysms with Guglielmi detachable coils

We reviewed the haemorrhagic complications of the endovascular treatment of intracranial aneurysms, in terms of frequency, pre-embolisation clinical status, clinical and radiological manifestations, management and prognosis. In 275 patients treated for 303 aneurysms over 7 years we had seven (one man and six women--2.3%) with haemorrhage during or immediately after endovascular treatment. All procedures were performed with a standardised protocol of heparinisation and anaesthesia. Four had ruptured aneurysms, two at the tip of the basilar artery, and one ach on the internal carotid and posterior cerebral artery, treated after 12, 5, 14, and 2 days, respectively, three were in Hunt and Hess grade 2 and one in grade 1. Bleeding occurred during coiling in three, after placement of at least four coils, and during manipulation of the guidewire to enter the aneurysm in the fourth. Haemorrhage was manifest as extravasation of contrast medium, with a sudden rise in systolic blood pressure in three patients. The other three patients had unruptured aneurysms; they had stable blood pressure and angiographic findings during the procedure, but one, under sedation, had seizures immediately after insertion of four coils, and the other two had seizures, headache and vomiting on the day following the procedure. Heparin reversal with protamine sulphate was started promptly started when bleeding was detected in four patients, and the embolisation was completed with additional coils in three. Emergency ventricular drainage was performed in the two patients with ruptured aneurysm and one with an unruptured aneurysm who had abnormal neurological responses or hydrocephalus. The bleeding caused a third nerve palsy in one patient, which might have been due to ischaemia and progressively improved.

Similarity and disparity of obsessive-compulsive disorder and schizophrenia in MR volumetric abnormalities of the hippocampus-amygdala complex

OBJECTIVES

Given that obsessive-compulsive disorder (OCD) and schizophrenia may share clinical symptoms as well as functional brain abnormalities, this study was designed to clarify common and different morphological abnormalities in OCD and schizophrenia.

METHODS

Volumes of the hippocampus, the amygdala, and the thalamus were measured in three age and sex matched groups of 22 patients with OCD, 22 patients with schizophrenia, and 22 normal subjects using three dimensional magnetic resonance imaging. Volume tracing was performed manually on serial coronal slices with the references of sagittal or axial planes using internal landmarks.

RESULTS

Hippocampal volume was bilaterally reduced in both OCD and schizophrenic patients versus the normal controls. Left amygdala volume was significantly enlarged in patients with OCD but not in patients with schizophrenia versus the normal controls. The thalamus did not show any volumetric group differences.

CONCLUSIONS

Non-specific hippocampal reduction in both the OCD and schizophrenic groups is likely to link to a clinical overlap between the two illnesses, whereas the left amygdala enlargement observed only in the OCD patients seems to be suggestive of a unique role for the amygdala in the pathophysiology of OCD.

Volume of cervical lymph nodes using 3D ultrasonography. Differentiation of metastatic from reactive lymphadenopathy in primary head and neck malignancy

PURPOSE

To assess the usefulness of volume measurement using 3D US for depicting metastatic cervical lymph nodes.

MATERIAL AND METHODS

Thirty-five cervical lymph nodes in 13 patients with primary head and neck malignancy were included in this study. US with volume acquisition was prospectively performed with a 5-10 MHz linear mechanical volume probe. Volume measurement of the node was calculated using a 3D automatic volume calculation program. The excised nodes matched on US were examined histopathologically.

RESULTS

The volume of malignant nodes ranged from 0.444 to 4.442 cm3, the volume of the benign nodes from 0.143 to 1.176 cm3. Combinations of high positive (>80%) and negative (>90%) predictive values were obtained at a cut-off value of 0.7 cm3.

CONCLUSION

Volume measurement of cervical nodes using 3D US can be a useful tool for differentiating metastatic from benign nodes in patients with primary head and neck malignancy.

Volume of cervical lymph nodes using 3D ultrasonography. Differentiation of metastatic from reactive lymphadenopathy in primary head and neck malignancy

PURPOSE

To assess the usefulness of volume measurement using 3D US for depicting metastatic cervical lymph nodes.

MATERIAL AND METHODS

Thirty-five cervical lymph nodes in 13 patients with primary head and neck malignancy were included in this study. US with volume acquisition was prospectively performed with a 5-10 MHz linear mechanical volume probe. Volume measurement of the node was calculated using a 3D automatic volume calculation program. The excised nodes matched on US were examined histopathologically.

RESULTS

The volume of malignant nodes ranged from 0.444 to 4.442 cm3, the volume of the benign nodes from 0.143 to 1.176 cm3. Combinations of high positive (>80%) and negative (>90%) predictive values were obtained at a cut-off value of 0.7 cm3.

CONCLUSION

Volume measurement of cervical nodes using 3D US can be a useful tool for differentiating metastatic from benign nodes in patients with primary head and neck malignancy.

An angiographic lesion mimicking pseudo-aneurysm in cerebral arteriovenous malformation

In cerebral arteriovenous malformations (AVMs), a pseudo-aneurysm represents rupture site, and its presence is known as a factor for rebleeding. We report a case of cerebral AVM presenting with intracerebral haemorrhage in which cerebral angiography showed a lesion mimicking pseudo-aneurysm. Although the patient needed urgent surgical decompression, it was delayed because early haematoma evacuation would induce rebleeding from the rupture site. The authors attempted to occlude the pseudoaneurysm interventionally before surgery. After surgical excision, the lesion that was believed to be a pseudo-aneurysm was revealed as a partially thrombosed venous sac having a thick fibrous wall. In this report, the authors discuss the pitfalls in the interpretation of pseudo-aneurysms in angiographic AVM architecture.

Grey matter abnormalities in obsessive-compulsive disorder: statistical parametric mapping of segmented magnetic resonance images

BACKGROUND

Although a number of functional imaging studies are in agreement in suggesting orbitofrontal and subcortical hyperfunction in the pathophysiology of obsessive-compulsive disorder (OCD), the structural findings have been contradictory.

AIMS

To investigate grey matter abnormalities in patients with OCD by employing a novel voxel-based analysis of magnetic resonance images.

METHOD

Statistical parametric mapping was utilised to compare segmented grey matter images from 25 patients with OCD with those from 25 matched controls.

RESULTS

Increased regional grey matter density was found in multiple cortical areas, including the left orbitofrontal cortex, and in subcortical areas, including the thalamus. On the other hand, regions of reduction were confined to posterior parts of the brain, such as the left cuneus and the left cerebellum.

CONCLUSIONS

Increased grey matter density of frontal-subcortical circuits, consonant with the hypermetabolic findings from functional imaging studies, seems to exist in patients with OCD, and cerebellar dysfunction may be involved in the pathophysiology of OCD.

Effects of protein kinase CK2, extracellular signal-regulated kinase 2, and protein phosphatase 2A on a phosphatidic acid-preferring phospholipase A1

A soluble, phosphatidic acid-preferring phospholipase A1, expressed in mature bovine testes but not in newborn calf testes, may contribute to the formation or function of sperm. Here we incubated a recombinant preparation of the phospholipase in vitro with several enzymes including protein kinase CK2 (CK2), extracellular signal-regulated kinase 2 (ERK2), and protein phosphatase 2A (PP2A) to identify effects that might be of regulatory importance in vivo. Major findings were that 1) CK2 phosphorylated the phospholipase on serines 93, 105, and 716; 2) ERK2 phosphorylated the enzyme on serine 730; 3) there was cross-antagonism between the reactions that phosphorylated serines 716 and 730; 4) PP2A selectively hydrolyzed phosphate groups that were esterified to serines 716 and 730; 5) CK2alpha formed a stable, MgATP/MgGTP-dependent complex with the phospholipase by a novel mechanism; and 6) the complex showed reduced phospholipase activity and resembled a complex identified in homogenates of macaque testis. These results provide the first available information about the effects of reactions of phosphorylation and dephosphorylation on the behavior of the phospholipase, shed light on properties of CK2alpha that may be required for the formation of complexes with its substrates, and raise the possibility that a complex containing CK2alpha and the phospholipase may play a special biological role in the testis.

Mutational and kinetic evaluation of conserved His-123 in dual specificity protein-tyrosine phosphatase vaccinia H1-related phosphatase: participation of Tyr-78 and Thr-73 residues in tuning the orientation of His-123

Active-site cysteine strategically positioned in the P-loop of protein-tyrosine phosphatases has been suggested to be further stabilized by hydrogen bonding arrays radiating out from the P-loop to neighboring residues. In this work, we investigated the structural role of histidine array in HC(X)(5)RS motif of the vaccinia H1-related protein phosphatase (VHR), using site-directed mutagenesis in conjunction with an extensive kinetic analysis. Conserved His-123 was mutated along with neighboring residues Tyr-78 and Thr-73. The increased pK(a) values of active-site Cys-124 found in Y78F and T73A mutants (6.51 and 6.75, respectively) were comparable to those of H123A and H123F mutants. Kinetic evaluation of Y78F and T73A mutants further implicates that the mutations perturb the relative position of Cys-124 within the P-loop. These results imply that Tyr-78 and Thr-73 make up an essential part of the His-123 array and structurally tune the Cys-124 position. Tyr-78 of VHR turns out to be the invariant Tyr reported in several protein-tyrosine phosphatases by a structure-based sequence alignment. Therefore, orientation of the imidazole ring of His-123 by the invariant Tyr-78 is crucial for maintaining the proper position of Cys-124 in the P-loop.

Miniature postsynaptic currents depend on Ca2+ released from internal stores via PLC/IP3 pathway

Miniature postsynaptic currents (mPSCs) were examined on autaptic innervation of single rat retinal ganglion cells in low density cultures. Removal of Ca2+ from bath solution or blocking of Ca2+ channels by Cd2+ had no detectable effect on mPSC frequency or amplitude. Thapsigargin, an agent for mobilization of Ca2+ from internal stores, increased mPSC frequency 3-5-fold in control, Ca2+-free or Cd2+-containing solutions. The inositol 1,4,5-triphosphate (IP3) receptor antago- nist, heparin; the phospholipase C (PLC) inhibitor, U73122; and caffeine abolished mPSC or decreased mPSCs frequency. Calcium imaging showed that cytosolic Ca2+ was increased by thapsigargin and decreased by caffeine. These data demonstrate that internal store-released Ca2+ regulated by the PLC/IP3/IP3-receptor pathway has critical contribution to generation and control of miniature release in retinal ganglion cells.

Comparative analysis of MR imaging, positron emission tomography, and ictal single-photon emission CT in patients with neocortical epilepsy

BACKGROUND AND PURPOSE

MR imaging, positron emission tomography (PET), and single-photon emission CT (SPECT) play important roles in presurgical localization of epileptic foci. However, comparative study of these imaging methods for cases of neocortical epilepsy has been limited. The purpose of this study was to compare the sensitivities of these three imaging methods for presurgical localization of neocortical epileptogenic foci.

METHODS

We studied 117 consecutive patients who underwent surgery for intractable neocortical epilepsy. The pathologic substrates were neuronal migration disorder (n = 77), tumor (n = 15), and others (n = 25). MR imaging was compared retrospectively with (18)F-fluorodeoxyglucose PET and ictal technetium-99m hexamethylpropyleneamine oxime SPECT regarding their capability to correctly localize the epileptogenic foci. The pathologic findings were used as the standard of reference.

RESULTS

Overall, MR imaging, PET, and ictal SPECT correctly localized the lesions for 59.8%, 77.7%, and 70.3% of the patients, respectively, with a 38% concordance rate among the three methods. PET was most sensitive (71-100%) in detecting all substrates. MR imaging was as sensitive (100%) as PET in detecting tumor but was least sensitive (48.1%) in detecting neuronal migration disorder. Ictal SPECT was more sensitive (75.8%) than MR imaging in detecting neuronal migration disorder. Patients with imaging abnormalities achieved good outcomes in 81.4% of the cases, in contrast to 59.5% for those without imaging abnormalities (P <.05).

CONCLUSION

PET and ictal SPECT were overall more sensitive than was MR imaging, despite the low concordance rate and variable sensitivity depending on substrates. The detection of abnormalities by MR imaging was associated with good outcome. PET or ictal SPECT can be well used as complementary tools, particularly in cases of negative MR imaging findings.

Carotid artery involvement in Takayasu's arteritis: evaluation of the activity by ultrasonography

The purpose of this study was to investigate the ultrasonographic criteria for determining the activity of carotid lesions in Takayasu's arteritis. In 10 consecutive patients, common carotid arteries with active lesions (n = 8) and inactive lesions (n = 9) were included in the study. The activity of the carotid lesions was determined on the basis of clinical and laboratory findings and computed tomographic scans. Special focus was placed on thickness and echogenicity of the involved arterial wall and outer diameter of the involved arterial segment. All 17 common carotid arteries evaluated showed segmental or diffuse circumferential thickening of the involved wall. The wall thickness was 2.5 to 5.0 mm (mean +/- SD, 3.3 +/- 0.8 mm) in active lesions and 1.1 to 2.0 mm (mean, 1.6 +/- 0.4 mm) in inactive lesions. The outer diameter of the involved segment was 7.0 to 15.0 mm (mean, 10.0 +/- 2.4 mm) in active lesions and 4.9 to 9.5 mm (mean, 6.8 +/- 1.4 mm) in inactive lesions. Active lesions showed hyperechogenicity in the full thickness of the involved wall (n = 6) or concentric triple layers with a hyperechoic middle layer (n = 2). Inactive lesions showed hyperechogenicity (n = 7) or isoechogenicity (n = 2) of the involved wall. One active lesion showed intramural arteries. Although precise measurement to tenths of a millimeter is impossible with the transducer used, prominent wall thickening with a maintained outer diameter in the common carotid artery suggests an active lesion, whereas mild wall thickening with a decreased outer diameter suggests an inactive lesion. Triple layers of a thickened wall with intramural arteries can be an ultrasonographic finding of an active lesion.

Lateralizing ability of single-voxel proton mr spectroscopy in hippocampal sclerosis: comparison with mr imaging and positron emission tomography

BACKGROUND AND PURPOSE

Proton MR spectroscopy (MRS) is still in the early stages in the evaluation of epilepsy, and comparisons with MR imaging and positron emission tomography (PET) in the same patients have rarely been documented. The purpose of this study was to evaluate the lateralizing ability of single-voxel MRS in comparison with MR imaging and PET in patients with hippocampal sclerosis.

METHODS

Thirty-three patients with intractable temporal lobe epilepsy whose MR imaging diagnosis was unilateral hippocampal sclerosis and who underwent anterior temporal lobectomy and had good postsurgical outcome over 1-year follow-up were included in the study. MR spectra were obtained from the hippocampus bilaterally, using the point-resolved spectroscopy sequence. Metabolite ratios of NAA/Cho and NAA/Cr were calculated from the relative peak height measurements. An NAA/Cho ratio of 0.8 or less and an NAA/Cr ratio of 1.0 or less were regarded as abnormal. The MRS results were compared retrospectively with those of MR imaging and PET as to the ability to lateralize the epileptogenic focus.

RESULTS

The sensitivity of MRS and PET (concordance with MR imaging) was 85% each in the lateralization of the ipsilateral lesion side. Bilateral abnormalities were seen in 30% of the patients. False-lateralization rates for MRS and PET were 3% and 6%, respectively. The concordance rate of MRS and PET was 73%, when comparing the results of the ipsilateral lesion side.

CONCLUSION

MRS may be used as an adjunct tool in the evaluation of hippocampal sclerosis, like PET, although its sensitivity has to be improved and the clinical significance of bilateral abnormality is still to be determined.

Spinal intradural extramedullary capillary hemangioma: MR imaging findings

SUMMARY

Spinal intradural extramedullary capillary hemangiomas are extremely rare. We present the MR imaging and histologic findings in three patients with this abnormality. The three patients were men who had symptoms of either myelopathy (n = 2) or radiculopathy (n = 1). The tumors were well demarcated, 1.5-2.0 cm in diameter, and were located at the posterior or posterolateral portion of the thecal sac (one at the L1 level and the other two at the midthoracic level). On MR images, the tumor showed isointensity relative to the spinal cord on T1-weighted images, hyperintensity on T2-weighted images, and strong homogeneous enhancement on contrast-enhanced T1-weighted images in all three patients. In two patients, the dural tail sign was observed. Capillary hemangioma should be included in the differential diagnosis of a spinal intradural extramedullary tumor.

Malignant melanoma of the sinonasal cavity: explanation of magnetic resonance signal intensities with histopathologic characteristics

PURPOSE

To evaluate the magnetic resonance (MR) findings of malignant melanoma of the sinonasal cavity and compare these findings with those of the histopathological examination.

MATERIALS AND METHODS

The MR images of 11 patients with malignant melanoma of the sinonasal cavity were retrospectively reviewed. Ten patients had primary malignant melanoma of the sinonasal cavity and one had a local recurrence. The imaging findings were evaluated with special attention given to the signal intensity of the tumor, internal characteristics, and growth pattern on MR. Signal intensity and enhancement patterns of the tumors were compared with the histopathological findings.

RESULTS

On T1-weighted image, 6 tumors were hyperintense (5 melanotic and one amelanotic melanoma), and 5 tumors were isointense or hypointense (4 amelanotic and one melanotic). On T2-weighted images, 2 amelanotic tumors showed hyperintensity, and 5 melanotic tumors showed hypointensity. Four tumors (one melanotic and 3 amelanotic) were isointense. Four of the 7 tumors with hyperintensity on T1-weighted images showed patchy, higher-signal intensity areas. In 3 of them, patchy areas of a higher degree of pigmentation were found on histopathological examination. There were multiple linear dark signal intensities on T2-weighted images and/or linear-enhancing areas on enhanced T1-weighted images within the masses in 5 of the 11 patients. These findings could be explained as intratumoral vessels in 4 tumors and fibrous septa in one tumor on histopathological examinations.

CONCLUSION

Malignant melanoma of the sinonasal cavity shows characteristic MR signal intensity, which is mainly attributable to the degree and distribution of melanin pigmentation, and partly attributable to hemorrhage within the mass. The linear, low-signal intensity on T2-weighted images or enhanced lines are intratumoral vessels or fibrous septa.

Diffusion-weighted MRI in cystic or necrotic intracranial lesions

Our purpose was to investigate the signal intensities of cystic or necrotic intracranial lesions on diffusion-weighted MRI (DWI) and measure their apparent diffusion coefficients (ADC). We examined 39 cystic or necrotic intracranial lesions in 33 consecutive patients: five malignant gliomas, seven metastases, two other necrotic tumours, a haemangioblastoma, three epidermoids, an arachnoid cyst, seven pyogenic abscesses, 12 cases of cysticercosis and one of radiation necrosis. DWI was performed on a 1.5 T unit using a single-shot echo-planar spin-echo pulse sequence with b 1,000 s/mm2. The signal intensity of the cystic or necrotic portion on DWI was classified by visual assessment as markedly low (as low as cerebrospinal fluid), slightly lower than, isointense with, and slightly or markedly higher than normal brain parenchyma. ADC were calculated in 31 lesions using a linear estimation method with measurements from b of 0 and 1,000 s/ mm2. The cystic or necrotic portions of all neoplasms (other than two metastases) gave slightly or markedly low signal, with ADC of more than 2.60 x 10(-3) mm2/s. Two metastases in two patients showed marked high signal, with ADC of 0.50 x 10(-3) mm2/s and 1.23 x 10(-3) mm2/s, respectively. Epidermoids showed slight or marked high signal, with ADC of less than 1.03 x 10(-3) mm2/s. The arachnoid cyst gave markedly low signal, with ADC of 3.00 x 10(-3) mm2/s. All abscesses showed marked high signal, with ADC below 0.95 x 10(-3) mm2/s. The cases of cysticercosis showed variable signal intensity; markedly low in five, slightly low in three and markedly high in four.

Palliatively treated cerebral arteriovenous malformations: follow-up results

The purpose of this study was to evaluate the benefits of palliative embolisation of patients with inoperable intracranial AVMs. It involved the analysis of the long-term clinical follow-up results of 27 patients with inoperable intracranial AVMs. Sixteen patients were treated medically and 11 patients received partial embolisation. The mean size of the lesions was 7.2 +/- 2.6 cm, and the mean follow-up period was 99 +/- 44 months (range 52-192 months). There were no significant statistical differences in the sex, age, size, venous drainage pattern, location of the lesions or presented symptoms. The analysis of the long-term clinical follow-up results showed no significant difference in either the risk of haemorrhage or clinical status of the patients in the two treatment groups. Of the 16 patients in the medical treatment group, 8 (50%) showed a clinical improvement, 3 no improvement and 5 (31%) deterioration. Of the 11 patients in the embolisation group, 5 (45.5%) showed clinical improvement, 3 no improvement and 3 (27.3%) deterioration (P = 0.871). Twenty-five percent (4 cases) of patients in the medical group and 45.5% (5 cases) of patients in the embolisation group suffered from haemorrhage during the follow-up period (P = 0.270). Complications related to embolisation occurred in three cases. This comparative study shows that palliative partial embolisation of intracranial AVMs, in all probability does not produce better clinical results than medical treatment.