Asymptomatic cerebral aneurysm in stroke patients eligible for intravenous thrombolytic therapy.

PURPOSE: To report two cases of acute ischemic stroke with anterior communicating artery aneurysm presented to emergency room within 3 hours after onset, and to review the literature. CASE REPORT: Two cases of previously unreported anterior communicating artery aneurysm were candidates for intravenous thrombolysis for their acute stroke. Recombinant tissue plasminogen activator was eventually withdrawn by other reasons. The aneurysms presented as nodular lesions with slightly increased density just above sellae turcica on non-contrasted computed tomography and were later diagnosed by magnetic resonance angiography. CONCLUSION: Asymptomatic cerebral aneurysm could be undiagnosed by non-contrasted computed tomography.Careful reading at selected regions can reduce pitfalls. Computed tomographic angiography and magnetic resonance angiography are alternative screening tools for thrombolysis if available in ER.The composite effect of r-tPA on cerebral aneurysms is still uncertain. A more inclusive definition of cerebral aneurysms and miscellaneous vascular anomalies in current criteria of thrombolysis is recommended.

Lactate peak on brain MRS in children with syndromic mitochondrial diseases.

BACKGROUND: Brain magnetic resonance spectroscopy (MRS) has been reported to be a valuable noninvasive tool in the diagnosis of some rare diseases. In this study, our aim was to assess lactate peak on single-voxel proton MRS in children with syndromic mitochondrial diseases (MDs). METHODS: From March 2004 to November 2010, 14 patients who were diagnosed with syndromic MDs underwent single-voxel proton MRS examination. The volume of interest was positioned on axial magnetic resonance imaging (MRI), and voxels were sampled using short (35 milliseconds), intermediate (144 milliseconds), or long (288 milliseconds) echo times for determination of lactate at 1.33 parts/million. RESULTS: Twelve of fourteen patients (85.7%) exhibited lactate peaks on the initial single-voxel proton MRS, and all of them showed abnormal MRI findings. The correlations of lactate level in blood and lactate peak on single-voxel proton MRS were inconsistent. Among the 12 patients, eight (66.7%) had corresponding elevated levels of blood lactate, and four (33.3%) had normal levels of blood lactate. Compared with a positive rate of 85.7% for patients with lactate peaks on the single-voxel proton MRS, the positive rates for diagnosing syndromic MDs by using electron microscopic examination of muscle biopsy, oral glucose lactate stimulation test, and blood lactate level were 100%, 91.7%, and 71.4%, respectively. CONCLUSION: Lactate acquisition on single-voxel proton MRS provides a noninvasive and complementary tool for the diagnosis of syndromic MDs, especially in children with abnormal signal changes on the brain MRI or a normal blood lactate level.

Obscure manifestations of Salmonella subdural empyema in children: case report and literature review.

PURPOSE: Salmonella intracranial infections, including subdural empyema and brain abscess, are rare clinical manifestations in children. The aim of this study is to investigate the clinical course of Salmonella subdural empyema in infants and children. METHODS: We report a 9-month-old female infant diagnosed as Salmonella subdural empyema with clinical features of prolonged fever for more than 2 months and episodic focal seizures. Literature published between 1986 and 2010 relevant to Salmonella subdural empyema in children were reviewed. The clinical presentations and laboratory findings were analyzed. RESULTS: Seventeen cases with Salmonella subdural empyema, including our index case, has been reported with detailed clinical presentation. Fever (17/17; 100%), symptoms and signs of increased intracranial pressure (8/17; 47%), seizures (8/17; 47%), and limb paralysis (8/17; 47%) were the most frequent clinical features. Among these cases, unknown causative organism prior to surgery (11/17; 65%) and prolonged fever for more than 3 weeks (5/17; 29%) were also noticed. Sixteen out of 17 patients (94%) required surgical intervention for treatment. The morbidity rate and mortality rate were 29% (5/17) and 6% (1/17), respectively. CONCLUSION: Subdural empyema is considered to be a disease with rapid progression. However, the cases caused by Salmonella species may present a slow disease course. Surgical intervention is sometimes the only way to detect the pathogen.

Measurements of normal inner ear on computed tomography in children with congenital sensorineural hearing loss.

The objective of this study is to use standardized measurements of the inner ear to see whether there are subtle bony malformations in children with congenital sensorineural hearing loss (SNHL) whose temporal bone computed tomography (CT) are grossly normal. The study includes 45 ears with congenital SNHL and grossly normal temporal bone CT scans and 45 ears with normal inner ear structures and normal hearing. Standardized measurements of the inner ear structures were made on axial temporal bone CT scans. Student's t test was performed to compare the measurements of the two groups. There were significant differences in the measurements of the bony island width of the superior semicircular canal, bony island width of the lateral semicircular canal and maximal height of cochlea between two groups (P < 0.05). In conclusion, standardized measurements of bony labyrinth of inner ear on temporal bone CT can identify subtle abnormalities of inner ear in patients with congenital SNHL having grossly normal radiological images.

Angioplasty as the first-line therapeutic option for venous hypertension with outlet obstruction of dural sinus.

We describe a nonconventional endovascular approach to the treatment of pseudotumor cerebri with venous outlet stricture or obstruction. In three patients presenting with acute visual loss, angiograms showed sinus occlusion and stasis of contrast material, with an increased pressure gradient in the venous system. We used venous sinus angioplasty as the first therapeutic option. This treatment was effective, and symptoms and signs of all three patients subsided quickly. In our initial and limited experience, sinus balloon angioplasty appeared to be a good first-line treatment for patients with pseudotumor cerebri, sinus outlet obstruction and acute vision loss. We prefer to use sinus stent placement as a second-line option when initial attempts are unsuccessful, especially in pediatric and young-adult patients, as illustrated in our cases.

Transcutaneous puncture of the superior ophthalmic vein for embolization of dural carotid-ophthalmic fistula.

SUMMARY: Carotid-ophthalmic fistula is a rare disease, which can be treated by transvenous endovascular embolization. Here, we report a unique case with draining vein thrombosed, making a transvenous approach impossible. An old but valuable technique, direct transcutaneous puncture of the superior ophthalmic vein, was used to save the patient's right eye. The old technique, direct puncture of the superior ophthalmic vein, retains its irreplaceable usefulness in this special situation. Thus, interventional neuroradiologists should equip themselves with this essential technique.

Cerebral sinovenous thrombosis. Neuroimaging diagnosis and clinical management.

SUMMARY: Cerebral sinovenous thrombosis (CSVT) is an uncommon disorder that affects the dural venous sinus and cerebral vein. In our study, thirty- four patients were examined. Pre and/or post contrast-enhanced CT was done in 28 patients. MRI studies were done in 24 patients. 2-D TOF MR venography (MRV) and contrast-enhanced MRV (CEMRV) were done in 19 cases. Digital subtraction angiography (DSA) was done in 18 patients. Sixteen patients received systemic intravenous heparinization, and 12 received endovascular thrombolytic treatment with urokinase combined with anticoagulant therapy. Neuroimages of CSVT can be acquired by direct visualization of the thrombus within the dural sinus or by parenchymal changes secondary to venous occlusion. As there are some pitfalls to MRI in the diagnosis of CSVT, the combination of MRI and MRV is now the gold standard in the diagnosis of CSVT. Usually, accuracy can be improved by applying 2-D TOF MRV and CE MRV. Furthermore, the source image of MRV is critical in differentiating between normal sinus variations and diseased ones. DSA is the best tool for demonstrating dynamic intracranial circulation in CSVT and mostly is used for endovascular treatment. Systemic intravenous anticoagulant therapy with heparin is accepted as a first line treatment. Except for clinical manifestations after systemic heparinization, abnormal MR findings of parenchymal change can be used to determine when to initiate thrombolytic treatment. Endovascular therapy can be finished at the antegrade flow within the dural sinus and continuous anticoagulation is sufficient to facilitate clinical improvement. Clinical suspicion and excellent neuroimaging are crucial in making the diagnosis of CSVT. Proper management with anticoagulants and/or endovascular thrombolytic therapy is mandatory in preventing propagation of the thrombosis and improving the clinical outcome.

Nasal NK/T-cell lymphoma: computed tomography and magnetic resonance imaging findings.

BACKGROUND: Primary nasal natural killer (NK)/T-cell lymphoma is the most common cellular subtype seen in nasal lymphomas. It is rare in the Western population but occurs more frequently in Asia, South America, and Mexico. The purpose of this study was to describe the computed tomography (CT) and magnetic resonance (MR) imaging findings of primary nasal NK/T-cell lymphoma. METHODS: During the period between January 1990 and June 2006, the CT (n=24) and MR (n=6) images of 24 patients with biopsy-proved nasal NK/T-cell lymphoma were reviewed retrospectively. Both CT and MR images were evaluated for site and extent of disease and for pattern of involvement of adjacent areas. RESULTS: The most common symptoms at presentation were nasal obstruction, nasal discharge, and epistaxis. There was involvement of the unilateral nasal cavity in 16, bilateral nasal cavity including nasal septum in 5 and nasal choana in 3. Sites of extension outside the nasal cavity included tumor extension into paranasal sinuses (n=15), nasopharynx (n=5), nasal labial fold (n=3), oropharynx (n=2), infratemporal fossa (n=2), other subcutaneous soft tissue of the face (n=2) and anterior cranial fossa base (n=1). Bony destruction was demonstrated in 18 cases, involving the sinus bony wall (n=15), nasal turbinate (n=10), lamina papyracea (n=6), orbital floor (n=3), and hard palate (n=2). Regional lymphadenopathy was also detected in 3 patients with nasal NK/T-cell lymphoma. CONCLUSION: The CT and MR appearances of nasal NK/T-cell lymphoma are nonspecific, and the diagnosis requires histologic confirmation. However, the differential diagnosis of nasal NK/T-cell lymphoma should be included if the images present soft tissue of the nasal cavity with bony erosion or destruction; involvement of the orbital cavity, nasopharynx and infratemporal fossa; and subcutaneous or nasolabial fold soft tissue infiltration, especially in Asian populations.

CT angiography and MR angiography in the evaluation of carotid cavernous sinus fistula prior to embolization: a comparison of techniques.

BACKGROUND AND PURPOSE: This study compared CT angiography (CTA), MR angiography (MRA), and digital subtraction angiography (DSA) in elucidating the size and location of carotid cavernous sinus fistulas (CCFs) before embolization treatment. METHODS: This was a retrospective study of 53 patients with angiographically confirmed CCF. All patients underwent pre- and postcontrast-enhanced CTA and DSA, and 50 patients also underwent MRA. Two neuroradiologists rated detectability of the fistula tract as "good," "moderate," or "poor" in source images obtained by using each procedure. The chi(2) test was used to compare the imaging modalities with respect to their ability to detect fistulas. RESULTS: CTA did not differ significantly from DSA (P = .155), and both CTA (P = .001) and DSA (P = .007) performed significantly better than MRA in the population as a whole. Differences in performance among the methods, however, depended upon the segmental location of the fistula along the internal carotid artery (ICA). CTA and MRA were similar in detection of CCFs in patients with a fistula at segment 3. CTA significantly outperformed MRA in patients with a fistula at segment 4, who accounted for approximately half of the population. CONCLUSIONS: CTA source imaging has proved itself as useful as DSA for detecting CCFs. Of the 2 noninvasive techniques, CTA performed better than MRA in the population as a whole and in most patients whose fistula was located at segment 4 or 5 of the ICA.

Nasopharyngeal carcinoma spreading along the eustachian tube: the imaging appearance.

Nasopharyngeal cancer (NPC) is one of the most common cancers in Taiwan. It can spread anteriorly, laterally, posteriorly, superiorly and inferiorly. Skull base invasion is the common presentation, in up to one-third of cases. We report a rare spreading pathway of NPC, via the eustachian tube. A 44-year-old male suffered from NPC and got radiotherapy about 2 years ago. He suffered from middle ear effusion and facial nerve palsy on the right side recently. The computed tomography and magnetic resonance image could clearly depict the infiltrating tumor over the mastoid region and tympanic cavity on the right side, spreading along the eustachian tube. It could result in eustachian tube dysfunction and middle ear effusion. The nature of the right facial palsy was most likely due to tumor infiltration.

Intraspinal extradural ganglion cyst of the cervical spine.

Intraspinal ganglion cyst is an uncommon lesion, which occurs most frequently in the lower lumbar region; occurrence in the cervical region is extremely rare. We report a case of ganglion cyst in the cervical region and describe its clinical pathological and radiological findings. A 59-year-old man presented with sudden lower limbs weakness and numbness below the nipple level. Magnetic resonance imaging revealed an intraspinal extradural lobulated cystic lesion at the level of C6-7 in contact with the left facet joint and posterior erosion of the spinal process at C7. The spinal cord was severely compressed by this lesion which was hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging and short T1 inversion recovery. The cyst wall was strongly enhanced after contrast injection. Intraoperatively, the mass was found to arise from the capsule of the C6-7 facet joint. The excised cyst contained jelly-like fluid. The patient's neurologic symptoms had fully recovered 20 days after the operation. The histopathologic analysis was consistent with ganglion cyst. Ganglion cyst of the cervical region is extremely rare, but must be considered in the differential diagnosis of intraspinal extradural compressive syndromes.