Jun-ichi Iida

Spinal dural arteriovenous fistula with perimesencephalic subarachnoid haemorrhage

A case is reported of a 66 year old woman presenting with perimesencephalic subarachnoid haemorrhage (SAH) which was caused by a spinal dural arteriovenous fistula at the C1 level. The fistula drained into the venous system of the posterior cranial fossa through a perimedullary vein. The bleeding was thought to result from venous hypertension induced by the fistula. This case may support the hypothesis that perimesencephalic non-aneurysmal SAH can be ascribed to venous bleeding and that venous hypertension is the key to its pathology.

Effect of Carotid Artery Stenting on Ocular Circulation and Chronic Ocular Ischemic Syndrome

Background: The authors evaluated the effect of carotid artery stenting (CAS) on ocular circulation and chronic ocular ischemic syndrome. Methods: We examined 38 patients with carotid artery stenosis (>80%) at its origin treated with CAS. Ocular circulation and symptoms were examined before, within 24 h, and 1 week, 1 month, and 3 months after CAS based on ophthalmic artery color Doppler flow imaging and ophthalmological examinations. Results: Ocular circulation: Before CAS, 13 patients showed reversed ophthalmic artery flow, and 25 antegrade flow. Average peak systolic flow velocity was –0.038 m/s. Within 24 h after CAS, all patients showed antegrade ophthalmic artery flow; reversed flow before CAS was thus resolved. Average peak systolic flow velocity rose significantly to 0.36 m/s (p < 0.05). One week, 1 month and 3 months after CAS, there were no significant changes compared to the findings at 1 week after CAS. Ocular symptoms: Before CAS, 8 patients showed chronic ocular ischemic syndrome. During the follow-up period (mean: 2.8 years), the visual acuity improved in 7 cases. Average retinal artery pressure and arm-to-retina circulation time improved significantly to the normal level (p < 0.05). The other 30 patients complained of recurrent and worsened visual symptoms during the follow-up period. Conclusion: CAS was effective in improving ocular circulation, and also improved the chronic ocular ischemic syndrome caused by the severe carotid artery stenosis.

Clinical features and management of brain arteriovenous malformations in elderly patients

Summary.Background. Brain arteriovenous malformations (AVMs) of the elderly have not received sufficient attention, given the increase in age of individuals in recent years. We therefore designed a retrospective study to clarify features of brain AVMs in this age group in comparison with their counterparts in the general population.Methods. A retrospective study was performed, based on data for AVMs treated in Nara Medical University Hospital and affiliated hospitals over the past 13 years. The series included all cases of brain AVMs, except for pure dural AVMs, diagnosed from June 1989 to June 2003. A total of 175 patients were diagnosed as having an AVM during this period, including 32 patients more than 60 years old. Clinical features and effective treatment of brain AVMs in those over and under 60 were explored and outcome at 3 to 6 months after surgery was evaluated according to a modified neurological scale.Findings. The most common mode of presentation was intracranial hemorrhage in both groups, and this was remarkable in the elderly. Epilepsy at presentation was less frequent in the elderly (P<0.05). In the elderly group infratentorial lesions were encountered more frequently (P<0.05). Good or excellent outcomes of surgery were accomplished in 82.6% of the non-elderly group, and in 69.6% of the elderly group. When restricted to the grades I or II of Spetzler and Martin (S & M) grading, postoperative neurological scores of both groups were significantly better than preoperative values (P<0.01). In the grade III cases, the non-elderly demonstrated significant improvement after surgery (P<0.01), but the elderly did not.Interpretation. Elderly patients with a brain AVM had clinical features of less frequent epileptic presentation and more frequent infratentorial lesions. It was suggested that surgery was acceptable in elderly patients with pallial AVMs of grade I and II. Surgery for grade III AVMs of the elderly remains to be clarified.

Ocular Circulation and Chronic Ocular Ischemic Syndrome before and after Carotid Artery Revascularization Surgery.

Background. We evaluated the effect of carotid revascularization surgery on ocular circulation and chronic ocular ischemic syndrome (OIS). Methods. We examined ninety patients with carotid artery stenosis (more than 50% stenosis) at its origin treated with carotid endarterectomy (N = 56) or carotid artery stenting (N = 34). Twenty-five patients (28%) complained of chronic OIS. Ocular circulation was examined before and after revascularization surgery using ophthalmic artery (OphAr) and central retinal artery (CRA) color Doppler flow imaging. Results. (1) Ocular circulation: preoperatively, the average OphAr peak systolic flow velocity (Vs) was 0.05 m/sec, and the average CRA Vs was 0.07 m/sec. At 1 week after surgery, the average OphAr Vs significantly increased to 0.32 (P < 0.05), and the average CRA Vs significantly increased to 0.11 m/sec (P < 0.05). These significant improvements were sustained throughout the three months of the followup. (2) OIS: during the follow-up period (mean: 3.6 years), 15 patients (60%) showed visual acuity improvement, and no patients complained of amaurosis fugax or worsening of the chronic OIS. Conclusion. Carotid revascularization surgery was effective in improving the ocular circulation, and it was also useful for the chronic OIS due to the carotid artery stenosis.

Wall imaging of cerebral aneurysms with a modified surface-rendering technique of spiral CT.

Summary¶ Background. There has been no detailed documentation of the advantages of three-dimensional (3D) wall imaging of cerebral aneurysms. The usefulness of such endoscopic images obtained with modified spiral computed tomography angiography (CTA) was therefore examined in comparison with conventional spiral CTA and digital subtraction angiography (DSA). Methods. Fifteen of 45 patients who underwent conventional spiral CTA in our department in the past 4 years, were further studied with a technical modification of surface-rendering reconstruction in spiral CT. Endoscopic images were obtained by regulating the lower and higher thresholds of spiral CT scans in processing. Digital subtraction angiography was also performed for 14 of the 15 patients. The 3D wall images of the cerebral aneurysms were assessed in comparison with findings from conventional CTA and DSA. Findings. The true orifice of the aneurysms could be visualized with the endoscopic mode in all of the 15 cases. In paraclinoid aneurysms, particularly below the anterior clinoid process, the relationships to associated vessels and bone structures were more clearly disclosed with this mode. The endoscopic images of aneurysms with rigid clots or neighboring distended veins were not as adversely affected as conventional CTA. In 4 of the 15 the wall imaging precisely located the branches arising from the dome of aneurysms which DSA could not. Interpretation. Wall imaging of complex or small cerebral aneurysms provided valuable information on their relationships to associated arteries and surrounding bony structures. The endoscopic mode, a simple modification of surface rendering, is easily available in commercial CT processing packages.