Taiji Yonezawa

Neuroprotective effect of suppression of astrocytic activation by arundic acid on brain injuries in rats with acute subdural hematomas

Acute subdural hematoma (ASDH) can cause massive ischemic cerebral blood flow (CBF) underneath the hematoma, but early surgical evacuation of the mass reduces mortality. The aim of this study was to evaluate whether arundic acid improves the secondary ischemic damage induced by ASDH. Our results confirmed that arundic acid decreases the expression of S100 protein produced by activated astrocytes around ischemic lesions due to cytotoxic edema after ASDH as well as reducing infarction volumes and numbers of apoptotic cells around the ischemic lesions. In this study, we also evaluate the relationship of brain edema and the expression of Aquaporin 4 (AQP4) in an ASDH model. The expression of AQP4 was decreased in the acute phase after ASDH. Cytotoxic edema, assumed to be the main cause of ASDH, could also cause ischemic lesions around the edema area. Arundic acid decreased the infarction volume and number of apoptotic cells via suppression of S100 protein expression in ischemic lesions without changing the expression of AQP4.

Extensive Parasellar Chondroma with Ollier's Disease

A 37-year-old woman with known Olliers disease presented with visual ®eld disturbance. Computed tomography and magnetic resonance imaging (Fig. 1 a) revealed a partially calci®ed or ossi®ed intracranial mass in the right parasellar region arising from the right upper clivus and cerebellopontine angle region. Three-dimensional axial reconstruction from axial CT data with contrast media demonstrated that the right internal carotid and anterior cerebral arteries were buried under the tumour (Fig. 1 b). Selective right internal and external carotid angiography revealed the large hypovascular mass to be displacing the carotid canal part of the right internal carotid artery antero-laterally and the anterior cerebral artery rostrally. Partial removal was performed through Le Fort I maxillotomy, revealing a soft, extradural, gelatinous tumour with a calci®ed component extending cranially. Histologically, the tumour cells, including double nucleated cells, demonstrated relatively high cellularity with mild atypia. The postoperative course was uneventful, and she returned to her job one month after the operation.

Giant true posterior communicating artery aneurysm

The case of a giant posterior communicating artery (PCoA) aneurysm is reported in which the clinical presentation was Korsakoffs syndrome. Left carotid angiography revealed a partially thrombosed giant PCoA aneurysm. Three-dimensional computed tomography angiography showed the precise neck of aneurysm and surrounding structures from a multidirectional view. Hypoperfusion of the bilateral frontal, temporal, and medial inferior thalamus was seen on single-photon emission computed tomography. According to previous reports, giant true PCoA aneurysms are rare; in fact, there has been only one report of a giant true PCoA aneurysm. We discuss the radiological characteristics and the clinical presentation of giant true PCoA aneurysms.

Evaluating the effect of superficial temporal artery to middle cerebral artery bypass on pure motor function using motor activation single photon emission computed tomography.

OBJECTIVE We evaluated and analyzed the effect of superficial temporal artery to middle cerebral artery bypass for internal carotid artery occlusion on pure motor function using motor activation single photon emission computed tomography. METHODS Motor activation single photon emission computed tomographic (SPECT) images were obtained for nine patients who had undergone superficial temporal artery to middle cerebral artery anastomosis for symptomatic internal carotid artery occlusion. All motor activation SPECT images using the finger opposition task on the affected side were obtained before bypass surgery and at 1 week, 1 month, and 3 months after bypass surgery. The results of motor activation single photon emission computed tomography were expressed as negative or positive. RESULTS Before bypass surgery, the resting SPECT images revealed reduction of cerebral blood flow (CBF) on the affected side in all nine patients. The results of motor activation single photon emission computed tomography in three patients were positive. One week after bypass surgery, the results of the resting and motor activation CBF studies did not demonstrate any marked changes. One month after bypass surgery, the resting CBF increased in four patients. The results obtained for two of the patients revealed preoperative positive motor activation. The results of motor activation single photon emission computed tomography obtained for five patients were positive. Three months after bypass surgery, eight patients experienced improvement in the resting CBF, and the results of motor activation single photon emission computed tomography obtained for seven patients were positive. Among these, the results of preoperative motor activation single photon emission tomography obtained for four patients were negative. CONCLUSION Superficial temporal artery to middle cerebral artery bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT images. From the preoperative motor activation study, it was concluded that patients with preoperative positive motor activation could attain the effect of bypass earlier than patients with preoperative negative motor activation.

Relationship Between Clinical Features and T2-Weighted Magnetic Resonance Images in Symptomatic Rathke Cleft Cysts

BACKGROUND It is not known when surgery is appropriate for the treatment for incidental Rathke cleft cysts because knowledge of their natural history is lacking. In this study, we sought to determine whether symptomatic Rathke cleft cysts could be distinguished by their signal intensities in magnetic resonance (MR) images. We analyzed the relationship between these signal intensities and clinical manifestations of the cysts and their patterns of expansion. METHODS MR signal intensities on T1-weighted (T1W) and T2-weighted (T2W) images for 52 cases were categorized into 3 types. Type 1 (20 cases) showed low signal intensities on T1W images and hyperintensity on T2W images. Type 2 (10 cases) showed hyperintensity on both T1W and T2W images. Type 3 (22 cases) showed hypointensity on T2W images. RESULTS A significantly higher proportion of patients with type 1 signal intensities had large cysts compressing their third ventricle than patients with the other 2 types of signal intensities. Patients with type 1 signal intensities also frequently had visual disturbances. Anterior pituitary dysfunction was observed more often in patients with type 2 or 3 signal intensities than in patients with type 1 intensities. CONCLUSIONS We conclude that Rathke cleft cysts that show an MR signal intensity similar to that of cerebrospinal fluid grow slowly and are frequently diagnosed as cysts associated with visual disturbance when they become large. It may be possible to predict the clinical progression of Rathke cleft cysts by assessing MR signal intensities.

Pituitary Apoplexy Caused by Hemorrhage From Pituitary Metastatic Melanoma: Case Report

Melanoma metastases to the pituitary gland are extremely rare, with only a few reported cases. We report an unusual case of pituitary metastatic melanoma in which the patient presented with pituitary apoplexy. A 68-year-old man presented general fatigue and anorexia following sudden headache. Neurological examination disclosed bitemporalhemianopsia. Computed tomography (CT) scans revealed a suprasellar mass including intratumoral hematoma. Magnetic resonance (MR) images demonstrated a circumscribed mass lesion in the intra- and suprasellar regions, compressing the optic chiasm. Surgical exploration was performed through a transsphenoidal approach, and a mixture of tumor and necrotic tissue with old hematoma was obtained. The histological examination of the specimen revealed a partly necrotic, malignant tumor with focal melanotic pigmentation. Histopathologically, the diagnosis was consistent with pituitary apoplexy caused by hemorrhage from pituitary metastatic melanoma.

Transdural Indocyanine Green Videography for Superficial Temporal Artery–to–Middle Cerebral Artery Bypass—Technical Note

BACKGROUND Neurosurgical application of indocyanine green (ICG) videography before performing a dural opening, known as transdural ICG videography, has been used during surgery of meningiomas associated with venous sinuses as well as cranial and spinal arteriovenous malformations. However, its use for a superficial temporal artery (STA)-to-middle cerebral artery (MCA) bypass has not been reported. METHODS We performed a retrospective analysis of medical records of patients who underwent transdural ICG videography during STA-MCA bypass performed between January 2012 and March 2015. The primary outcome was visualization of recipient cortical arteries; secondary outcomes were surgical modifications and complications as well as any adverse events associated with transdural ICG videography. RESULTS We analyzed 29 STA-MCA bypass procedures performed in 30 hemispheres with atherosclerotic steno-occlusive disease and found that the proper recipient was identified in 28 hemispheres. Subsequently modified procedures for those were a tailored dural incision and craniotomy correction. No complications associated with ICG administration were encountered; during the postoperative course, transient aphasia was noted in 1 case, chronic subdural hematoma was noted in 1 case, and subdural effusion was noted in 2 cases. CONCLUSIONS Transdural ICG videography for atherosclerotic steno-occlusive disease facilitates modifications during STA-MCA bypass procedures. Recognition of the proper recipient cortical arteries before a dural incision allows the neurosurgeon to perform a tailored dural incision and extension of the bone window, although the contribution to surgical outcome has yet to be determined.

Blooming artery sign in proximal posterior inferior cerebellar artery dissection.

A 46-year-old man developed vertigo and vomiting, and came to us the next day. The patient had no risk factors related to cerebrovascular disease except for current smoking status. Neurological examinations demonstrated a left-beating horizontal nystagmus and cerebellar sign on the left side. Non-contrast computed tomography (CT) revealed a low-density area in the left cerebellum in the area of the posterior inferior cerebellar artery (PICA) (Fig. 1a). In magnetic resonance (MR) angiography findings, the left PICA was invisible and the vertebral artery (VA) was intact (Fig. 1b), while a hypo-intense ‘‘blooming’’ artery sign was noted in the left PICA in T2*weighted MR image (Fig. 1c). Digital subtraction angiography (DSA) demonstrated abruption of the PICA without definite aneurysmal dilatation (Fig. 1e). We treated the patient with an intravenous administration of glycerol and the free radical scavenger edaravone. No anticoagulant or antiplatelet agents were given. Seven days after the ischemic onset, the patient had a sudden severe headache and vomiting, and CT demonstrated a newly developed diffuse subarachnoid hemorrhage (SAH) (Fig. 1d). DSA revealed a saccular-like aneurysm at proximal PICA just after branching off from the left VA (Fig. 1f). Emergency surgery was performed via a lateral suboccipital approach. Intraoperatively, the aneurysm was saccular in shape and arose at the bend of the PICA itself just after branching off from the intact VA, while the aneurysmal sac and continuous distal PICA wall were dark purple in color. The PICA was occluded by surgical clipping at its origin. No new ischemic lesions developed after the operation.

Endovascular Therapy for the Steal Phenomenon due to the Innominate Artery Severe Stenosis and Bilateral Internal Carotid Artery Severe Stenosis

BACKGROUND Symptomatic innominate artery stenosis presenting as hemodynamic bilateral cerebral ischemia is uncommon. We present a rare case of the severe stenosis of the origin of an innominate artery and severe stenosis of bilateral internal carotid artery that induced hemodynamic cerebral ischemia after ipsilateral axillary artery-bilateral femoral artery bypass and was treated with stent replacement of the innominate artery and right internal carotid artery. CASE REPORT A 64-year-old woman who previously had undergone right axillary artery-bilateral femoral artery anastomosis for abdominal aorta high obstruction had been suffering from chronic dizziness and so visited our department. Findings of the examination included the severe stenosis of the origin of an innominate artery and severe stenosis of bilateral internal carotid artery, causing hemodynamic cerebral ischemia. She underwent stent replacement of the innominate artery and right carotid artery stenting via a right transbrachial approach. Her symptoms were relieved postoperatively. DISCUSSION For the sake of improving the hemodynamic cerebral ischemia, we performed stent replacement for innominate artery stenosis and right carotid artery stenting. Endovascular treatment of subclavian and innominate artery disease is a safe procedure. In addition, for the protection of thromboembolic migration, we performed balloon protection of the external carotid artery and filter protection of the internal carotid artery. CONCLUSIONS Stent replacement for these lesions can be performed safely with the right approach and protection methods, even when the only accessible route is the right brachial artery.