Assessment of cerebral circulation in the acute phase of subarachnoid hemorrhage using perfusion computed tomography

BACKGROUND AND PURPOSE

Primary brain damage, caused by acute ischemic changes during initial hemorrhage, is an important cause of death and disability following subarachnoid hemorrhage (SAH). However, the mechanism underlying the reduction in cerebral circulation in patients in the acute stage of SAH remains unclear. The goal of this study was to clarify this mechanism with the aid of perfusion computed tomography (CT).

METHODS

We prospectively evaluated 21 patients who had been undergone perfusion CT within 3 hours of SAH onset. Mean transit time (MTT) was estimated. Forty circular regions of interest 5 mm in diameter were delineated in the cortical region of the bilateral hemispheres on perfusion CT images. Neurological condition was graded with the Hunt and Hess scale, and initial CT findings were graded with the Fisher scale. We defined a good outcome as a modified Rankin scale (mRs) score of ≤2 at 3 months after SAH onset.

RESULTS

Global MTT was an independent predictor of outcome. The global MTT of patients with poor outcomes was longer than that of patients with good outcome. Furthermore, global MTT correlated significantly with Hunt & Hess grades, and disturbances in higher cerebral function.

CONCLUSION

Hemodynamic disturbances frequently occur after SAH. These abnormalities probably reflect the primary brain damage caused by initial hemorrhage. Perfusion CT is valuable for detecting hemodynamic changes in the acute stages of SAH.

Feasibility of 4D flow MR imaging of the brain with either Cartesian y-z radial sampling or k-t SENSE: comparison with 4D Flow MR imaging using SENSE

PURPOSE

A drawback of time-resolved 3-dimensional phase contrast magnetic resonance (4D Flow MR) imaging is its lengthy scan time for clinical application in the brain. We assessed the feasibility for flow measurement and visualization of 4D Flow MR imaging using Cartesian y-z radial sampling and that using k-t sensitivity encoding (k-t SENSE) by comparison with the standard scan using SENSE.

MATERIALS AND METHODS

Sixteen volunteers underwent 3 types of 4D Flow MR imaging of the brain using a 3.0-tesla scanner. As the standard scan, 4D Flow MR imaging with SENSE was performed first and then followed by 2 types of acceleration scan-with Cartesian y-z radial sampling and with k-t SENSE. We measured peak systolic velocity (PSV) and blood flow volume (BFV) in 9 arteries, and the percentage of particles arriving from the emitter plane at the target plane in 3 arteries, visually graded image quality in 9 arteries, and compared these quantitative and visual data between the standard scan and each acceleration scan.

RESULTS

4D Flow MR imaging examinations were completed in all but one volunteer, who did not undergo the last examination because of headache. Each acceleration scan reduced scan time by 50% compared with the standard scan. The k-t SENSE imaging underestimated PSV and BFV (P < 0.05). There were significant correlations for PSV and BFV between the standard scan and each acceleration scan (P < 0.01). The percentage of particles reaching the target plane did not differ between the standard scan and each acceleration scan. For visual assessment, y-z radial sampling deteriorated the image quality of the 3 arteries.

CONCLUSION

Cartesian y-z radial sampling is feasible for measuring flow, and k-t SENSE offers sufficient flow visualization; both allow acquisition of 4D Flow MR imaging with shorter scan time.

Microcystic meningioma with late-phase accumulation on thallium-201 single-photon emission computed tomography: case report

Microcystic meningiomas are rare but benign brain tumors. Previous reports have shown that Thallium-201 single-photon emission computed tomography ((201)Tl SPECT) demonstrated a higher late-phase accumulation of (201)Tl in malignant or recurrent meningiomas than in nonaggressive meningiomas. No study has reported (201)Tl SPECT findings in microcystic meningiomas. We here describe a case of a microcystic meningioma with a high (201)Tl SPECT retention rate in a 62-year-old woman who complained of headache. Computed tomography revealed an intracranial tumor in the right frontal lobe. Moreover, (201)Tl SPECT revealed a high uptake of (201)Tl in the tumor, which was particularly prominent in the delayed phase. The uptake index on an early image was 1.46 and that on a delayed image was 1.35. Therefore, the retention index was 0.92. After 2 years of tumor growth, we performed successful radical resection, and histological examination revealed the presence of a microcystic meningioma. Therefore, we concluded that (201)Tl SPECT may be useful for the preoperative diagnosis of microcystic meningiomas and that late-phase accumulation of (201)Tl is not a specific finding of malignant brain tumors. Therefore, we need to be careful in the evaluation and judgment of high retention in a delayed image of (201)Tl SPECT.

3.0-T diffusion images after clipping of middle cerebral artery aneurysm

AIM

Replacement of aneurysm clips or temporary parent artery occlusion during aneurysm clipping (AC) carries the risk of inducing postoperative neurologic deficits. When studying the risk of surgical complications associated with cerebral aneurysms, patients with similar conditions should be compared to eliminate the influence of rupture and location of aneurysm.

MATERIAL AND METHODS

We used 3.0-Tesla (3.0T) magnetic resonance diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA) to analyze surgical complications after AC. A total of 42 AC procedures for 40 unruptured and 2 delayed-phase ruptured MCA aneurysms were evaluated.

RESULTS

In six patients, temporary parent artery occlusion was performed. Asymptomatic hyperintensities were observed on DWI of three patients. In one patient, an asymptomatic lesion was most likely caused by a small contusion that occurred during dissection of an aneurysm attached to the brain surface. In two patients, asymptomatic cortical lesions were caused by brain surface contusions due to lacerations of the open dura. No symptomatic hyperintensities on DWI were observed after surgery. No fixed ischaemic neurologic deficits resulted from AC.

CONCLUSION

Although some postoperative abnormalities were observed with 3.0T DWI, we found clipping of MCA aneurysms to be a safe procedure with a low risk of ischaemic complications.

Pathophysiology and management of intracranial arterial stenosis around the circle of Willis associated with hyperthyroidism: case reports and literature review

Cases of moyamoya disease or intracranial arterial stenosis around the circle of Willis (M/IAS) associated with hyperthyroidism have been reported. However, most of these previous reports were of the ischemic form of M/IAS and primary hyperthyroidism. To the best of our knowledge, no studies have documented therapy for M/IAS associated with hyperthyroidism. We discuss four previously unreported cases, including those involving the intracerebral hemorrhage form and thyroid-stimulating hormone (TSH) secretion from a pituitary adenoma (secondary hyperthyroidism). We analyzed data from 52 previously reported cases, including the 4 cases presented here, and discuss M/IAS associated with hyperthyroidism, treatment options, pathophysiology, the ischemic and hemorrhagic forms, secondary hyperthyroidism, and the relevant literature. Hyperthyroidism results in thyrotoxicosis and the stimulation of the superior cervical ganglion by TSH antibodies and f-T3/f-T4. Consequently, hypercoagulability and stenosis of the cerebral artery can occur. There are many reports of ischemic M/IAS associated with hyperthyroidism. A conservative approach to treatment is important in such cases; for example, antithyroid therapy should be the first choice to treat ischemic M/IAS. There have been only a limited number of reports on hemorrhagic M/IAS. We presume that hemorrhagic M/IAS tears the weakened vasculature in a manner similar to that of normal M/IAS (with no complicating hyperthyroidism). The authors also reported M/IAS associated with secondary hyperthyroidism due to pituitary thyroid secreting hormone secreting adenoma.

Infantile cerebellar pilocytic astrocytoma with autism spectrum disorder

The etiology of autism remains unclear, but relationships to cerebellar factors have been reported. We report 2 cases of infantile cerebellar pilocytic astrocytoma in children with autism spectrum disorder. Cerebellar tumors may be related to the pathogenesis of autism.

Posttraumatic carotid-cavernous fistulae treated by internal carotid artery trapping and high-flow bypass using a radial artery graft--two case reports

Two patients presented with post-traumatic carotid-cavernous sinus fistulae (CCFs) that were successfully treated by high-flow bypass using a radial artery graft after initial unsuccessful attempts at obliteration by intravascular embolization. Case 1 was a 20-year-old man with a CCF detected by magnetic resonance imaging and angiography following an accident. Although the CCF appeared partially occluded by intravascular embolization, serial angiography revealed CCF recurrence. The CCF was trapped by placing a high-flow bypass. Case 2 was a 21-year-old man who presented with bilateral CCFs after sustaining face trauma. The bilateral CCFs were directly treated because of recurrence after balloon occlusion. At present, intravascular surgery is the first treatment choice, but placing a high-flow bypass with trapping of the CCF gained time to treat the CCF and may be useful for treating post-traumatic CCF that cannot be effectively eliminated by intravascular techniques.

Supratentorial extraventricular anaplastic ependymoma in an adult with repeated intratumoral hemorrhage

We report the case of a 61-year-old man with supratentorial extraventricular anaplastic ependymoma who presented with repeated intratumoral hemorrhage. The patient was admitted with headache. Computed tomography and magnetic resonance imaging showed an enhancing mass with intratumoral hemorrhage in the right temporal lobe. Gross total resection was performed. The tumor was well demarcated from the brain tissue, and showed no continuity with the ventricular system. Histopathological examination revealed the features of anaplastic ependymoma. Therefore, additional radiation therapy and adjuvant chemotherapy were administered. Ten months later, the tumor recurred with hemorrhage in the spinal canal. This case showed rapid malignant progression and repeated intratumoral hemorrhage within a short period of time, both of which are characteristics of anaplastic ependymomas. Close observation of the central nervous system and adjuvant radiotherapy are mandatory, even if the ependymoma presents with repeated intratumoral hemorrhage.

Surgical technique for the prevention of cerebrospinal fluid leakage after bifrontal craniotomy

BACKGROUND

Cerebrospinal fluid leakage and meningitis caused by frontal sinus (FS) exposure are characteristic complications of bifrontal craniotomy used for treating skull base tumors and anterior communicating artery aneurysms. Prevention of these complications is of utmost importance. We describe in detail our procedure for sealing exposed FSs during bifrontal craniotomy and present the results and outcomes of the procedure.

METHODS

A total of 51 consecutive patients who had undergone bifrontal craniotomy for tuberculum sellae meningiomas, craniopharyngiomas, anterior cerebral artery aneurysms, or other frontal skull base lesions at our institute were selected for the study. Our technique for sealing exposed FSs is described below. The mucosa was sterilized using surgical cotton dipped in iodine. After craniotomy, the exposed mucosa was sealed using 7-0 nylon sutures, whereas Gelfoam with fibrin glue was used to ensure watertight closure. The exposed portions of the FSs were covered by bone covers made of internal table bone and sealed. As a final layer, frontal periosteal flaps were sutured to the frontal base dura mater.

RESULTS

Postoperative cerebrospinal fluid leakage or meningitis did not occur in any of our patients.

CONCLUSION

Our results indicate the effectiveness of our technique in the prevention of FS-related postoperative complications.

Subarachnoid hemorrhage of unknown etiology along the cortical convexity

BACKGROUND

Only 8% to 22% of cases of subarachnoid hemorrhage (SAH) are of nonaneurysmal origin. Among these, perimesencephalic nonaneurysmal SAH is a distinct clinical and radiologic entity with normal angiographic findings and a good prognosis. In contrast, SAH of nonaneurysmal origin occurring along the cortical convexity is rare and poorly understood. We report 2 cases of subarachnoid hemorrhage along the cortical convexity and discuss their possible etiologies.

METHODS

In a retrospective analysis of 234 patients with SAH, we identified 2 patients with a typical computed tomographic pattern of convexity SAH that was associated with no known etiology.

RESULTS

In these 2 cases, the source of hemorrhage could not be identified with computed tomography, magnetic resonance imaging, or digital subtraction angiography, although neurovascular outcomes were good. The patients reported such incidents as coughing or exertion immediately before headache developed. These incidents may have caused increased intracranial pressure.

CONCLUSION

We suggest the possible involvement of a brief increase in intracranial pressure, such as that accompanying coughing or exertion, in the occurrence of SAH along the cortical convexity.

Perioperative complications of superficial temporal artery to middle cerebral artery bypass for the treatment of complex middle cerebral artery aneurysms

OBJECT

Only a few studies have reported the risk of ischemic complications occurring when superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis is performed during surgery for complex MCA aneurysms.

SUBJECTS AND METHODS

This is a retrospective study of 10 patients (age 52-73) with MCA aneurysms treated with revascularization surgery. The aneurysms were 10-50mm in size (mean: 21mm). We studied the causes and frequency of ischemic complications by analyzing postoperative magnetic resonance imaging.

RESULTS

Postoperative diffusion-imaging confirmed ischemic complications in six of the 10 patients (in two of the five ruptured aneurysms and in four of the five unruptured). The ischemic complications that observed were infarction of the lenticulostriate artery territory in three cases, cortical infarction in two cases, and cerebral infarction that was likely to be due to cerebral vasospasm in one case. In one case, both cortical infarction and infarction of the lenticulostriate artery territory were observed. The Glasgow Outcome Scale (GOS) scores at the time of discharge indicated good recovery (GR) and moderate disability (MD) in seven cases, severe disability (SD) in two cases, and death (D) in one case.

CONCLUSIONS

The present study suggests the possibility that STA-MCA anastamosis in surgeries for MCA aneurysms can be performed with comparatively better safety. However, the temporary occlusion time with this surgery is longer than that with a temporary clipping for aneurysmal surgery; thus, we believe that adequate countermeasures are required to prevent ischemic complications.

Intraoperative Matas test using microscope-integrated intraoperative indocyanine green videoangiography with temporary unilateral occlusion of the A1 segment of the anterior cerebral artery

OBJECTIVE

The aim of the present study was to assess a new technique of surgical microscope-based indocyanine green (ICG) videoangiography (VAG) to confirm the patency of the anterior communicating artery (AcomA) after clipping AcomA aneurysms.

METHODS

Aneurysmal clipping of five cases of unruptured, broad-neck AcomA aneurysm was performed using the Carl Zeiss Surgical Microscope OPMI Pentero INFRARED 800.

RESULTS

In all five patients, after clipping AcomA aneurysms, the patency of AcomA was confirmed using ICGVAG findings and temporary unilateral occlusion of the A1 segment of the anterior cerebral artery using temporary clips. Images were excellent and enabled a real-time surgical assessment because the structures of interest, including vessels, perforating arteries, or residual aneurysm neck, were visible to the surgeon's eye under the microscope in all five patients.

CONCLUSIONS

ICGVAG and temporary unilateral occlusion with clips provides a simple, reliable, real-time, and rapid intraoperative assessment of the patency of AcomA. This technique may help to improve the quality of neurosurgical procedures.

Activation of protein kinase A and C prevents recovery from persistent depolarization produced by oxygen and glucose deprivation in rat hippocampal neurons

Intracellular recordings were made from rat hippocampal CA1 neurons in rat brain slice preparations to investigate whether cAMP-dependent protein kinase (PKA) and calcium/phospholipid-dependent protein kinase C (PKC) contribute to the membrane dysfunction induced by oxygen and glucose deprivation (OGD). Superfusion of oxygen- and glucose-deprived medium produced a rapid depolarization ∼5 min after the onset of the superfusion. When oxygen and glucose were reintroduced immediately after the rapid depolarization, the membrane depolarized further (persistent depolarization) and reached 0 mV after 5 min from the reintroduction. The pretreatment of the slice preparation with PKA inhibitors, H-89 and Rp-cAMPS, and an adenylate cyclase inhibitor, SQ 22, 536, significantly restored the membrane toward the preexposure potential level after the reintroduction of oxygen and glucose in a concentration-dependent manner. On the other hand, a phospholipase C inhibitor, U73122, a PKC inhibitor, GF109203X, and a nonselective protein kinase inhibitor, staurosporine, also significantly restored the membrane after the reintroduction. Moreover, an inositol-1,4,5-triphosphate receptor antagonist, 2-aminoethyl diphenylborinate, and calmodulin inhibitors, trifluoperazine and W-7, significantly restored the membrane after the reintroduction, while neither an α-subunit-selective antagonist for stimulatory G protein, NF449, a Ca(2+)/calmodulin-dependent kinase II inhibitor, KN-62, nor a myosin light chain kinase inhibitor, ML-7, significantly restored the membrane after the reintroduction. These results suggest that the activation of PKA and/or PKC prevents the recovery from the persistent depolarization produced by OGD. The Ca(2+)/calmodulin-stimulated adenylate cyclase may contribute to the activation of PKA.

Utility of the orbitocranial approach for clipping of anterior communicating artery aneurysms: significance of dissection of the interhemispheric fissure and the sylvian fissure

OBJECTIVE

To investigate the importance of sufficient dissection of the interhemispheric and sylvian fissures, an orbitocranial approach was used for clipping of ruptured anterior communicating artery aneurysms.

PATIENTS AND METHODS

From January 1998 through March 2009, 41 patients underwent surgery for subarachnoid hemorrhage caused by rupture of an anterior communicating artery aneurysm. Their mean age was 58.4 years, with a range of 37 to 84 years. The preoperative World Federation of Neurosurgical Societies grade was I to III in 32 patients and IV to V in 9 patients. The direction of the aneurysm was upward in 23 patients, forward in 14 patients, and backward in 4 patients. Seven patients had a large aneurysm.

RESULTS

All patients underwent surgery during the acute stage following the subarachnoid hemorrhage (day 0-2). A right orbitocranial approach was used for most patients, but a left orbitocranial approach was used for 9 patients because of the presence of a complicated aneurysm and the positional relationship of the left-right A2 segment. In 12 patients, external decompression was performed. The outcome, using the Glasgow Outcome Scale, was good recovery in 24 patients, moderately disabled in 8 patients, and severely disabled in 4 patients, and 5 patients died. Temporary eye movement disorders developed after surgery in 5 patients but resolved in all patients within 2 months. No patients had olfactory disturbance.

DISCUSSION

Using the orbitocranial approach and sufficient dissection of the interhemispheric and sylvian fissures, we could secure a broad field of vision and surgical field, which contributed to a safe operation. The only postoperative complication caused by the surgical approach was temporary eye movement disorder. Thus, for some patients with aneurysms of the anterior communicating artery, the orbitocranial approach contributes to improved outcomes.

Indocyanine green videoangiography of optic cavernous angioma - case report -

The intraoperative findings of an indocyanine green videoangiography (ICG-VAG) study of a cavernous angioma located in the optic chiasm are reported. A 23-year-old Japanese man suddenly developed visual field loss, and magnetic resonance imaging suggested the presence of a suprasellar tumor in contact with the optic chiasm. Preoperative angiography did not clearly show any tumor shadow. Right fronto-temporal craniotomy was performed, and an aggregation of blood vessels was seen on the right surface of the optic chiasm. Cavernous angioma was suspected. ICG-VAG was begun 22 seconds after the beginning of contrast agent infusion via a peripheral blood vessel. The lesion remained unstained, although the brain surface, an artery superior to the optic nerve, and veins were visualized. The cavernous angioma was resected following surface coagulation. ICG-VAG is currently being evaluated for future application in the differential diagnosis based on imaging findings, and the present case provides an important example of intraoperative ICG-VAG imaging of an unoperated cavernous angioma.

Cerebral artery restenosis following transluminal balloon angioplasty for vasospasm after subarachnoid hemorrhage

Background:

Although percutaneous transluminal angioplasty (PTA) is a widely used less invasive method to treat coronary artery stenosis, 10% of treated patients experience restenosis. Restenosis also occurs in approximately 5% of patients subjected to carotid artery stenting. Animal and human data suggested that restenosis is a response to injury incurred during PTA. As PTA has come into wide use to manage symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH) we studied the incidence of restenosis after PTA for cerebral vasospasm.

Methods:

Our study population consisted of 32 patients who had undergone PTA. They were followed by cerebral or 3DCT angiography or MRA for 6 126 months post-PTA (mean 48.65 months) to diagnose restenosis of the cerebral artery. We compared the size of the cerebral artery on the PTA and the contralateral side.

Results:

All 32 patients underwent successful PTA of 38 vascular territories and all manifested angiographic improvement of vasospasm. None suffered restenosis during the follow up period.

Conclusion:

PTA resulted in a significant improvement in the vessel diameter in patients with vasospasm after SAH and they did not suffer restenosis in the course of prolonged follow-up.