Comparison of Time-of-Flight-Magnetic Resonance Angiography From Silent Scan Magnetic Resonance Angiography in Depiction of Arteriovenous Malformation of the Brain.

OBJECTIVE: Silent magnetic resonance angiography (MRA) was compared with time-of-flight (TOF)-MRA in imaging of arteriovenous malformations (AVMs) of the brain. METHODS: Thirty-five consecutive patients with AVMs of the brain were included. Quantitative analyses were performed by measuring both signal-to-noise ratio and contrast-to-noise ratio of the nidus. Qualitative analysis (scores 1-4) was performed by evaluating depictions of feeding arteries and draining veins independently by 2 reviewers. RESULTS: Both signal-to-noise ratio and contrast-to-noise ratio in TOF-MRA were significantly higher than those in silent MRA. For both feeders and drainers, scores were significantly higher in silent MRA than in TOF-MRA for both reviewers. Interrater agreement was higher in silent MRA than in TOF-MRA. CONCLUSIONS: Silent MRA visualized feeders and drainers in AVMs significantly better than did TOF-MRA. Interrater agreement was also better in silent MRA.

Comparison of Rates of Growth between Unruptured and Ruptured Aneurysms Using Magnetic Resonance Angiography.

BACKGROUND AND PURPOSE: Growth is a key risk factor for rupture of unruptured cerebral aneurysms. There are few reports of investigations into the actual growth of ruptured intracranial aneurysms. The aim of the present study was to ascertain the risk of rupture of aneurysms based on the growth of unruptured and ruptured aneurysms. METHODS: Changes in size on magnetic resonance angiography (MRA) were examined in 50 patients with ruptured cerebral aneurysms. Images obtained before and after subarachnoid hemorrhage were used. Moreover, changes in aneurysm size were retrospectively examined in 73 patients with 100 unruptured cerebral aneurysms that were followed serially with MRA that was performed using a 1.5-T or 3-T system. The size of the aneurysm was determined by measuring the maximum diameter on maximum intensity projection MRA images. Based on these data, the annual growth rates (mm growth/year) of unruptured and ruptured aneurysms were calculated and compared. RESULTS: The median annual growth rate of ruptured aneurysms was significantly greater than that of unruptured aneurysms (.69 versus .077 mm/year, P < .01). The annual growth rates of ruptured aneurysms showed a negative correlation between the duration from initial MRA to the time of rupture. CONCLUSION: A high annual growth rate is a key risk factor for aneurysm rupture. This finding provides strong evidence for the treatment of unruptured cerebral aneurysms.

Hemifacial Spasm Caused by Compression of a Vertebral Artery Aneurysm Consequently Improved by Stent-assisted Coil Embolization.

Objective: We described a rare hemifacial spasm (HFS) caused by compression of a vertebral artery (VA) aneurysm that was consequently improved by stent-assisted coil embolization. Case Presentation: A 60-year-old man presented with a chief complaint of left HFS that had persisted for 1 month. It had initially appeared in the orbicularis oculi, spread to the orbicularis oris, and severely disrupted his quality of life. Both MRI and MRA revealed a wide-necked aneurysm of the left VA (neck 8.5 mm, dome 6.0 mm) compressing the left facial nerve root exit zone (REZ). We performed stent-assisted coil embolization because the VA was dominant at this side of the aneurysm and we tried to preserve normal antegrade flow. The HFS disappeared immediately after embolization without complications. After 6 month follow-up, the patient had no recurrence of symptoms and MRA showed no recurrence of the aneurysm. Conclusion: Stent-assisted coil embolization was effective for treating HFS caused by compression of a VA aneurysm and it might be the treatment of choice for this type of aneurysmal HFS.

Pathophysiology of cerebral circulatory disorders in idiopathic normal pressure hydrocephalus.

This study was conducted to elucidate the pathologic conditions of cerebral circulatory disorders in idiopathic normal pressure hydrocephalus (iNPH). Among 44 possible iNPH patients, 40 patients underwent shunt surgery based on diagnostic flow charts plotted by the Southern Tohoku method and were evaluated to be shunt-effective at the end of the first post-surgical month. The cerebral blood flow (CBF) was measured by N-isopropyl-((123)I)-P-iodo-amphetamine single photon emission computed tomography (mean, mCBF; cortical region, cCBF; thalamus-basal ganglia region, tbCBF on autoradiography [ARG] method) and the perfusion patterns of the cerebral cortex were measured based on three-dimensional stereotactic surface projection (3D-SSP) Z-score images, before and 1 month after the surgery in all 40 subjects. The mCBF rose significantly from 32.1 +/- 2.74 ml/100 g/min before surgery to 39.8 +/- 3.02 ml/100 g/min after surgery (p < 0.03). Investigation of the change of CBF revealed reductions in the cCBF (3 cases), tbCBF (9 cases), and cCBF + tbCBF (28 cases), with the reduced-cCBF group totaling 31 cases and the reduced-tbCBF group totaling 37 cases. Investigation of cerebral cortex hypoperfusion by 3D-SSP Z-score revealed 31 cases with hypoperfusion (frontal lobe type [19 cases], occipitotemporal lobe type [5 cases], mixed type [7 cases]) and nine cases with cortical normoperfusion (N). The pattern of reduction of the cortical blood flow on ARG method was favorably correlated with the pattern of hypoperfusion of the cerebral cortex on 3D-SSP Z-score images before surgery. A reduction of blood flow was found in the thalamus-basal ganglia region of all N type cases. The blood flow improved in 19 of 31 (61.3%) cases of the reduced-cCBF group and in 32 of 37 (86.5%) cases of the reduced-tbCBF group. All of the cases without detectable improvement exhibited increased blood flow in non-reduction areas. Investigation of the hypoperfusion patterns of the cerebral cortex on 3D-SSP Z-score images, revealed a reduction or disappearance of the hypoperfusion site in 19 of 31 (61.3%) cases, either no-change or a shift of the hypoperfusion site in 12 of 31 (38.7%) cases, and a correlation between the pattern of cortical blood flow reduction on ARG method and the pattern of cerebral cortex hypoperfusion on 3D-SSP Z-score images after surgery. Cerebral circulatory disorders in iNPH manifest as either of two pathophysiological conditions: the "circulatory disorder of the cerebral cortical region" and the "circulatory disorder of the thalamus-basal ganglia region." Various patterns develop according to the disease stage.

[Postoperative patterns of improvement of symptoms and degrees of satisfaction in families of patients after operations for definite idiopathic normal pressure hydrocephalus: a long-term follow-up study].

PURPOSE: To clarify the patterns of improvement of pre- and post-operative symptoms and family satisfaction in patients with definite idiopathic normal pressure hydrocephalus (iNPN) who responded well to shunt intervention. SUBJECTS AND METHODS: The subjects included 40 patients definitively diagnosed with iNPH and who were followed up for one year or longer (age, 61-85; male-to-female ratio, 18: 22). The study focused on (1) preoperative clinical symptoms, (2) improvements in symptoms at 1, 3, 5, and 12 months after surgery, and the satisfaction of the families based on medical results of the Zarit caregiver burden interview, and infomation through questionnaires to medical personnel. RESULTS: (1) The major symptoms were gait disturbance (G, n=38), dementia (D, n=10), and urinary incontinence (U, n=23). G and D appeared as initial symptoms in 30 and 10 cases, respectively. (2) The rates of postoperative improvement at 1, 3, 5, and 12 months were 94.7%, 94.7%, 97.4%, and 94.7% for G, 43.8%, 62.5%, 71.9%, and 84.4% for D, and 78.3%, 86.96%, 86.96%, and 91.3% for U, respectively. G and U cases improved during the postoperative early stage, and D improved gradually from after the third postoperative month. The family satisfaction before surgery and at 1, 3, 5, and 12 months after surgery was 72.5 +/- 12.8, 68.1 +/- 15.4, 55.7 +/- 9.6, 52.9 +/- 11.4, and 47.3 +/- 7.9 points, respectively. The rate of improvement in satisfaction was higher for D. The satisfaction of the medical personnel was 88 percent (+) at 1 month and tended to remain high for 12 months. CONCLUSION: (1) Preoperative gait disturbance is a major initial symptom in definitively diagnosed iNPN. (2) Postoperative improvement of G and U is obtained at an early stage. In contrast, D tends to improve gradually from after the third postoperative month. The family satisfaction increases as the symptom of D improve. The satisfaction of the medical personnel tends to remain high after the first postoperative month. This study investigated the results of quantitative analyses of the patients symptoms.

Experimental model of intracranial arteriovenous shunting in the acute stage.

A model of intracranial arteriovenous (AV) shunting must incorporate local hypoperfusion and simulate the hemodynamics of arteriovenous malformations. In this study, the hemodynamics of an intracranial AV shunt model in the acute stage were clarified. End-to-side anastomoses with a femoral vein graft were performed between a cortical branch of the middle cerebral artery (MCA) and the superior sagittal sinus in anesthetized dogs. Local cerebral blood flow (l-CBF) was measured by laser Doppler blood flowmetry. l-CBF decreased suddenly by 34.2% when the shunt was opened in the ipsilateral MCA territory. Upon re-occlusion, l-CBF immediately equaled or exceeded the pre-opening value and returned to the pre-opening value within the next 15 minutes. Opening the shunt produced little change in l-CBF in the territory of the ipsilateral or contralateral anterior cerebral artery. The decrease in l-CBF was correlated with shunt volume only in the MCA territory. l-CBF manifested a PaCO(2)-dependent increase before shunt opening, but CO(2) reactivity was impaired after opening the shunt only in the MCA territory. This dog model features local hypoperfusion due to intracranial AV shunting and disturbance of CO(2) reactivity in the acute stage. The hemodynamics of this model will be confirmed in the chronic stage.

[Reinvestigation of CSF outflow resistance value in idiopathic normal pressure hydrocephalus--comparing epidural pressure monitoring with lumbar subarachnoid cerebrospinal fluid pressure monitoring].

PURPOSE: To compare the cerebrospinal fluid (CSF) outflow resistance values (Ro) with epidural pressure (EDP) monitoring and lumbar subarachnoid CSF pressure (L-CSFP) monitoring. SUBJECTS AND METHODS: The subjects were 14 patients with possible iNPH (age: 59-74 years old, ratio of male and female 8:6). All the patients were subjected to an infusion test by a single bolus injection method (1 ml/sec., deltaV: 5 ml, t2: 2 min) as prescribed in the Standard of SINPHONI. EDP was monitored by continuous monitoring and the L-CSFP values By intermittent simple glass tube method (SINPHONI) were measured simultaneously. The Ro (RoEDP, RoL-CSFP) calculated from both methods, (1) the correlation of Ro and (2) the Ro threshold in a shunt effective group (E: nine cases) and a non effective group (NE, five cases) were compared. RESULTS: (1) Although a favorable correlation was found between both Ro measurements (r=0.784), the RoEDP was always higher than the RoL-CSFP. (2) The mean Ro values in the E and NE groups were 36.8 +/- 15.7 mmHg/ml/min, and 10 +/- 2.05 mmHg/ml/min for Ro-EDP, 22.1 +/- 13.95 mmg/ml/min and 6.4 +/- 1.7 mmHg/ml/min for RoL-CSFP, respectively. The approximate thresholds in the E and NE groups were 15 mmHg/ml/min for RoEDP and 10 mmHg/ml/min for RoL-CSFP. CONCLUSION: (1) Although the RoEDP is always higher than the RoL-CSFP, a favorable correlation is found between the RoEDP and RoL-CSFP, (2) The Ro thresholds of the E and NE groups in the infusion test are about 15 mmHg/ml/min for RoEDP and 10 mmHg/ml/min for RoL-CSFP. (3) After this, Ro calculation ought to execute by standard of SINPHONI and the Ro threshold of the E and NE groups is about 10 mmHg/ml/min.

[Significance of shunt efficacy decision of SPECT on idiopathic normal pressure hydrocephalus].

PURPOSE: The purpose of this study was to investigate the significance of the shunt-effect evaluation of SPECT in idiopathic normal pressure hydrocephalus (iNPH). SUBJECTS AND METHODS: The subjects were 15 patients with possible iNPH, aged 62-83 (mean 75.3, the ratio of males to females to 6:9), who were treated at our department during the period from June to September, 2004. All patients received the lumbar tap test (LTT) at the outpatient section before surgery. An L-P shunt was conducted on patients whose the LTT positive or negative with cerebrospinal fluid outflow resistance value (Ro) was 10 mmHg/ml/min. or higher patients. As for SPECT, a 3D-SSP Z-score, as well as an mCBF, was conducted before and after the LTT and within one month after surgery. Comparisons were made for (1) the shunt effect, (2) mCBF before and after the LTT and after surgery, (3) mean cerebral blood flow increase rate (mIR) after the LTT, and (4) 3D-SSP before and after surgery. RESULTS: (1) The shunt was effective for all the patients. (2) The mCBF levels was 30.8 +/- 4.02 ml/100 g/min. before the LTT, 37.1 +/- 100 g/min. after the LTT, and 38.6 +/- 3.4 ml/100 g/min. after surgery. A significant increase in mCBF was observed both after the LTT and after surgery (p < 0.05). (3) The mean mIR after the LTT was 21.2 +/- 8.01%, with all the patients showing 10% or higher. (4) The ischemic patterns in the SD-SSP Z-score before surgery were the frontal type (F: 10 cases, 66.7%), the occipitotemporal type (OT: 3 cases, 20%), and the mixed type (M: 2 cases, 13.3%), but not the parietal localized type. The post-operative course showed no-change in 4 cases, disappearance-reduction in 9 cases, and shift to OT in 2 cases. CONCLUSION: The evaluation factors in the measurement of the cerebral blood flow for evaluation of the shunt effect were the following two items. (1) The mIR of mCBF after the LIT was 10% or higher. (2) As for the preoperative cerebral ischemic patterns, there were many F cases and no parietial localized types found.