Assessment of dural arteriovenous fistulas of the cavernous sinuses on 3D dynamic MR angiography

BACKGROUND AND PURPOSE

Flow voids within the cavernous sinuses and/or certain venous drainage on spin-echo MR imaging and time-of-flight (TOF) flow enhancement on MR angiography (MRA) have indicated high-velocity shunt flow and have been used for screening patients with dural arteriovenous fistulas (DAVFs) of the cavernous sinuses. In this investigation, the capabilities of 3D dynamic MRA as a flow-independent approach and those of conventional MR imaging techniques were compared with selective angiography for the diagnosis of DAVFs of the cavernous sinuses.

MATERIALS AND METHODS

This retrospective study involved 18 patients with angiographically proved DAVFs of the cavernous sinuses and 12 control subjects. Sixteen partially overlapping sequential MR images were acquired on contrast-enhanced 3D dynamic MRA between the petrosal bone and the orbital roof. Two experienced observers blinded to the clinical data and results of angiography independently graded 3D dynamic MRA, fast spin-echo T2-weighted imaging (FSE T2WI), and TOF MRA.

RESULTS

The average area under the receiver operating characteristic curve values and interobserver kappa scores for the diagnosis of DAVFs on 3D dynamic MRA, FSE T2WI, and TOF MRA were 0.99, 0.89, and 0.95; and 0.92, 0.71, and 0.73, respectively. Those for the diagnosis of anterior, posterior, and retrograde cortical venous drainage on 3D dynamic MRA were 0.72, 0.95, and 0.81; and 0.56, 0.50, and 0.49, respectively.

CONCLUSION

In this small series, screening 3D dynamic MRA directly demonstrates DAVFs of the cavernous sinuses and has improved diagnostic capability.

Interstitial spinal-cord oedema in syringomyelia associated with Chiari type 1 malformations

OBJECT

The pathophysiology of syringomyelia in Chiari type 1 malformations has not been clarified. Oedema-like spinal-cord swelling was recently reported in several pathological conditions, including Chiari type 1 malformations as a pre-syrinx state. However, the role of the pre-syrinx state in the development of syringomyelia is unknown. The purpose of this study is to investigate the parenchymal changes of the spinal cord in syringomyelia associated with Chiari type 1 malformations.

METHODS

Pre- and postoperative MRI findings in 14 patients who underwent foramen magnum decompression in our institute were reviewed. The analysis was focused on differences in visualisation of the syrinx between T1- and T2-weighted images and abnormal parenchymal signal changes. There were 6 men and 8 women, aged from 6 to 79 years. No patients showed hydrocephalus.

RESULTS

Twelve patients had large and expansive syrinx, whereas 2 patients showed small syrinx confined to the centre of the spinal cord. T2-weighted images displayed significantly larger intramedullary abnormal signal areas. Nine patients showed parenchymal hyperintensity areas around the enlarged central canal or base of the posterior white columns adjacent to the syringomyelic cavity. Such parenchymal hyperintensity areas markedly diminished with reduction of the syrinx after surgery and were considered to be interstitial oedema.

CONCLUSIONS

From this study, the interstitial oedema of the spinal cord commonly accompanies syringomyelia with Chiari type 1 malformations. Accumulation of the extracellular fluid due to disturbed absorption mechanisms may play an important role in the pathophysiology of syringomyelia associated with Chiari type 1 malformations.

[A case of tentorial meningioma presented with pure word deafness]

It has been known that an isolation of Wernicke's area from auditory input results in pure word deafness. In this report, a 73-year-old female case with tentorial meningioma suffering from pure word deafness is reported. The patient initially presented with hydrocephalus, and was treated with a ventriculo-peritoneal(V-P) shunt. A year after the V-P shunt, she suffered from a symptom of deafness. On admission, her repetition and auditory comprehension were severely impaired, while reading and visual comprehension were almost normal. Auditory brain stem response(ABR) revealed normal latency between wave I and V, while wave VI and VII was disappeared. Middle latency response(MLR) showed no wave peak. On MRI, tentorial meningioma compressed bilateral medial geniculate bodies, but not auditory radiation or temporal lobe. 99mTc-HMPAO single photon emission computed tomography(SPECT) showed hypoperfusion in the left temporal lobe, considered as a diaschisis resulting from the isolation of left temporal lobe from auditory input via bilateral medial geniculate bodies.

[Usefulness of galea suturing method for scalp closure]

A method for scalp closure to prevent alopecia along a suture line is described. Only the galea is sutured. By tacking a sufficient width of the galea on both sides with an absorbable suture material, the sutured wound forms a ridge. The outer layer is then closed with skin staples to keep the blood circulation undisturbed. This procedure contrasts with the traditional method in which the galea is sutured with the overlying subcutaneous tissue and consequently the hair follicles are strangled. By adopting the method of suturing the galea, development of alopecia along a suture line has been effectively prevented and scarring has become less conspicuous.

[A case of peripheral, fusiform type aneurysm originating from the superior cerebellar artery]

We reported a case of a 33-year-old woman who presented a subarachnoid hemorrhage due to rupture of an aneurysm arising from the ambient segment of the superior cerebellar artery (SCA). The patient who complained of severe headache and nausea was admitted on April 6, 1996. A CT scan revealed subarachnoid hemorrhage in the left cerebellopontine cistern. Left vertebral angiography showed a fusiform type aneurysm of the ambient segment of the left SCA. Trapping of the aneurysm was successfully performed via the subtemporal approach on the day of admission, April 6, 1996. She was discharged with no deficits on May 2, 1996. Fusiform type aneurysm arising from SCA is very rare. Only 3 cases have been reported in the literature. We discussed the pathogenesis of this aneurysm and the timing of surgery.

Cerebral venous sinus thrombosis associated with systemic multiple hemangiomas manifesting as chronic subdural hematoma--case report

A 35-year-old male was admitted with headache, nausea, and vomiting persisting for 2 days. Computed tomography (CT) revealed a left chronic subdural hematoma. Cerebral angiography demonstrated cerebral venous sinus thrombosis (CVST). He had presented with a subcutaneous mass involving the neck at age 2 years, which was shown to be a cavernous angioma, and thereafter shown signs of consumptive coagulopathy with systemic multiple hemangiomas. Burr hole aspiration of the hematoma was performed. Seventy-two-hours later, he developed clouding of consciousness and right hemiparesis. CT revealed a fresh hematoma in the operated subdural cavity and hemorrhagic diathesis manifested. A frontotemporoparietal large craniotomy was performed to remove the hematoma. Extensive electrocauterization was required. He had a satisfactory postoperative course. Collateral venous pathways, resulting from the CVST due to systemic multiple hemangiomas, may have caused hemodynamic stress in the bridging veins which subsequently induced chronic subdural hematoma.

[A case of cerebral aneurysm located at the leptomeningeal artery associated with occlusion of the middle cerebral artery]

A case is presented of a ruptured aneurysm located at a leptomeningeal artery associated with an occlusion of the anterior trunk of the middle cerebral artery. A 60-year-old male had a sudden onset of severe headache and hemiplegia. CT showed a left frontal subcortical hematoma. Cerebral angiograms demonstrated an occlusion of the anterior trunk of the left middle cerebral artery with moyamoya phenomenon. In addition, an aneurysm was found arising from the leptomeningeal artery. The parent artery was filled with contrast medium from the middle internal frontal artery. We have reviewed literature and discussed the cause of an aneurysm located at the leptomeningeal artery. Hemodynamic factors were strongly suggested as the reason for the aneurysmal formation in this case.

[Traumatic occlusion of the bilateral vertebral arteries associated with fracture of the cervical spine--a case report]

A case of traumatic occlusion of the bilateral vertebral arteries associated with fracture of the cervical spine is reported. A 34-year-old man, having no previously noted medical problems, fell to the bottom of a bathtub with a depth of 80 cm, and hit the vertex fronto-parietal region of his head. He was transferred to our hospital 6 hours after his fall with a crush fracture of the cervical spine at the C6 level. On admission he was alert, but having pain in the vertex region, dysarthria, blurred vision and hemiparesis. Roentgenograms confirmed a crush fracture of the C6 vertebral body. Computed tomograms of the brain revealed a high density of basilar artery. Cervical traction with a Halo brace was then carried out. Twelve hours after the trauma, left oculomotor and right facial palsy appeared followed by bilateral oculomotor palsy and respiratory difficulty. At the 14th hour, he displayed bilateral Babinski's signs and tetraparesis. Tetraparesis became complete with right-side Horner's syndrome at 16 hours. Cerebral arteriograms performed 20 hours after the trauma showed a complete occlusion of the right vertebral artery and an incomplete occlusion of the left vertebral artery at the C6-7 intervertebral disk space. Conscious level deteriorated to a 200 level on the Japan coma scale 28 hours after the trauma and to a 300 level after 32 hours. Computed tomograms revealed a marked low density on the cerebellum and brain stem 38 hours after the accident. He expired on the 22nd day after the trauma.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative evaluation of tablet lubricants: effect of application method on tablet hardness and ejectability after compression

The effect of four lubricants (stearic acid, magnesium stearate, calcium stearate, and talc) on the ejectability and hardness of statically compressed tablets of a lactose granulation was examined. Two methods of application of these lubricants, incorporation into the granulation and mixing with the granulation, were compared. In both methods, the energy consumption curves during ejection and the hardness curves with lubricant concentration were similar and showed complicated behavior at a lower concentration. The mixing method gave better results for ejectability and hardness than the incorporation method.