We applied 3D MR cisternogram/angiogram fusion imaging to 9 cases of the idiopathic trigeminal neuralgia for the preoperative assessment of the offending vessels for microvascular decompression (MVD). Fusion images of the 3D MR cisternogram/angiogram were reconstructed by a perspective volume-rendering algorithm from the volumetric data set of MR cisternography (black blood image), obtained by a T2-weighted 3D fast spin-echo sequence, and composed with the co-registered MR angiography (bright blood image), obtained by a 3D time-of-flight sequence with and without contrast medium. The complex anatomical relationship of the offending vessels, including superior cerebellar artery, anterior inferior cerebellar artery, posterior inferior cerebellar artery, vertebral artery and superior petrosal vein, to the root entry zone of the trigeminal nerve was preoperatively assessed on the fusion images from various viewpoints in the cerebellopontine angle cistern and through the simulated surgical approach. The 3D visualization of the nerve-vessel relationship with fusion images was comparative to the intraoperative findings. Fusion imaging of 3D MR cisternogram/angiogram may prove useful in preoperative assessment of MVD for the idiopathic trigeminal neuralgia.

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In 2004, Japanese guidelines for idiopathic normal pressure hydrocephalus (iNPH) were created to diagnose it more precisely and treat it more effectively. The guidelines suggested the importance of a tight cerebrospinal fluid (CSF) space at the high convexity area. We reviewed MRI/CT findings in 38 cases of probable iNPH during Jan. 1998 to Dec. 2003. We noted the tightness in the interhemispheric fissure on axial MRI/CT view. Thirty-three cases were shunt-responsive among 38 cases (shunt effectiveness: 86.8%). MRI/CT findings of iNPH on axial view were classified into typical, almost typical and atypical. Major findings of typical cases showed: l) ventricular dilatation, 2) tight interhemispheric fissure, 3) dilated Sylvian fissure. Almost all of the typical cases were a little bit questionable on findings for 2) and/or 3). Atypical cases showed an absence of finding 2) or showed aqueductal stenosis. Among 33 the shunt-responding cases, ten cases (30%) were typical, 16 cases (49%) were almost typical and seven cases were atypical. Among the 5 cases of non-responders, they were divided into 2, 2 and 1 cases, respectively. Atypical cases included 2 cases of aqueductal stenosis and 5 cases of open interhemispheric fissure; the latter were difficult to differentiate form brain atrophy. Thus, about 80% of iNPH cases could be diagnosed or highly suspected on axial MRI/CT findings. Although MRI/CT findings were not definitive for making a diagnosis of iNPH, they were highly useful to idenitify patients for a CSF tap test.

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Fenestration of the anterior communicating artery (ACoA) associated with saccular aneurysm are infrequent experienced anomaly. In previous reports, the neck clipping against the saccular aneurysm on fenestration has been difficult to perform. We present a case report of saccular aneurysm at the site of ACoA fenestrations. A 56-year-old man presented with an intraventricle hemorrhage underwent the cerebral angiography, which confirmed a ruptured saccular aneurysm of the ACoA. We performed neck clipping on the first day after the onset of intraventricle hemorrhage. During surgery we found that the fenestrated vessels were adhered to the aneurysmal sac and were trapped with aneurysm. Complete neck clipping is the ideal procedure for the aneurysm at the fenestration. As a postoperative result, the patient remained in memory disturbance. We discussed the neurosurgical strategies for the saccular aneurysm on the fenestration of the ACoA.

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We report a case of coil embolization of a recurrent aneurysm following complete prior clipping. A 75-year-old woman suffered from a second subarachnoid hemorrhage due to regrowth and rerupture of the left internal carotid posterior communicating aneurysm. Ten years previously, the patient had been treated by a complete neck clipping for the ruptured aneurysm. We performed coil embolization of the recurrent aneurysm followed by ventriculo-peritoneal shunting. She was discharged with good performance status. Effective obliteration of the aneurysm lasted during the follow-up period of one year. We consider coil embolization to be an effective treatment for recurrent aneurysm following a prior clipping surgery.

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We report two cases of polycystic kidney disease (PKD) associated with rapidly enlarging intracranial aneurysms. In the first case, a 38-year-old woman developed a subarachnoid hemorrhage (SAH) due to a ruptured anterior communicating aneurysm. Four years later, she developed a second SAH due to the rupture of a rapidly growing right middle cerebral artery (MCA) aneurysm. A de novo aneurysm was also found at the distal portion of the right MCA. In the second case, a 58-year-old woman presented with a 3.3-mm basilar tip aneurysm detected by screening MR angiography (MRA). A follow-up MRA, conducted 5 years later, showed that the aneurysm had grown to 6.6mm. An angiography showed other aneurysms at both the right and left sites of the MCA, in addition to the basilar tip aneurysm. In light of our experience, we emphasize that aneurysms complicated with PKD may enlarge relatively quickly. Therefore, close follow-up is needed for PKD associated cerebral aneurysms.

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We experienced a patient with acute progressing floating thrombus (FT) in the cervical carotid artery (CCA). A 66-year-old man presented with a transient ocular ischemic attack and was treated with oral antiplatelets just after diagnosis of a mild-grade stenosis of the left carotid artery by ultrasound scan (US). But during 6 days after the onset, several ocular ischemic attacks occurred and repeated carotid US revealed a pulsatile FT on the lesion. Thirteen days later, despite the patient being placed on anticoagulant and antiplatelet therapy, carotid US demonstrated no remarkable regression of the floating thrombus. The patient underwent carotid artery stenting using intraprocedual carotid US, which was valuable to visualize the safe conduit through the floating thrombus. The details of the procedure were described.

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We report a case treated successfully by carotid endarterectomy (CEA) combined with balloon PTA of a long severe stenotic lesion of the internal carotid artery (ICA). A 77-year-old male was admitted with brain infarction. Carotid angiography showed a long stenotic lesion from the origin to the petrous portion of the ICA. Immediately after standard CEA, balloon percutaneous transluminal angioplasty (PTA) using intraoperative digital subtraction angiography (DSA) was performed for treating the residual distal stenotic lesion. Histopathological findings showed that newly formed vessels in the atheromatous plaque indicated recanalization of the occluded ICA. Well-planned surgery and endovascular techniques can be complementary in the management of patients suffering from such long stenotic lesions of the ICA.

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We present a 61-year-old immunocompetent man with cerebellar abscess caused by Nocardia spp. The patient came to our hospital because of progressive consciousness disturbance. The patient's past medical history was not significant for immunodeficiency. CT demonstrated a right cerebellar mass lesion and obstructive hydrocephalus. Contrast Enhanced MRI demonstrated multiple ring-enhanced cerebellar cystic lesions. Intra-cystic fluid showed remarkable hyper-intensity on diffusion-weighted MRI. Posterior fossa decompression and echoguided aspiration were performed. The diagnosis of Nocardial cerebellar abscess was obtained by culture. Though the residural lesions were not diminished by TMP/SMX (ST) and meropenem (MEPM), these lesions were diminished by oral administration of minocycline (MINO). Due to drug-induced hepatitis, it was necessary to discontinue MINO after 6 weeks. However, there have not been any relapses of cerebral nocardiosis for 11 months postoperatively. Brain abscesses caused by Nocardia are rare, especially in immnocompetent patients. Standard treatment guidelines for cerebral nocardiosis were unavailable, and the mortality rate remains high. Though long-term follow-up remains necessary, stereotactic aspiration and sensitive antibiotic therapy have been successful in the short term.

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