Yoshio Tokuda

Chronic hydrocephalus in elderly patients following subarachnoid hemorrhage

BACKGROUND With the aging of the population, surgery for ruptured intracranial aneurysms is increasing among the elderly. We sought to clarify the characteristics of chronic hydrocephalus following aneurysmal subarachnoid hemorrhage (SAH) in elderly patients. METHODS Of the 576 surgically treated patients, 289 were aged 59 years or younger, 169 were 60 to 69, and 118 were 70 years or older. The relationship between chronic hydrocephalus and the causative factors was analyzed for each age group. RESULTS Of the 576 patients, chronic hydrocephalus was observed in 215 (37%), with the incidence increasing significantly with age (p < 0.001) and being the highest in the oldest age group. In elderly patients, the incidence of chronic hydrocephalus was relatively high, even after mild SAH. The incidence of chronic hydrocephalus was high regardless of age in patients with severe SAH, such as in those with H&H grades III-IV, SAH grades III-IV, acute hydrocephalus, symptomatic vasospasm, and intraventricular hemorrhage, and in those with vertebro-basilar artery aneurysms. CONCLUSION In the elderly, the incidence of chronic hydrocephalus following SAH was significantly higher than in younger patients, even after mild SAH. In elderly patients, careful observation and individualized treatment are necessary even if SAH is mild.

The superoxide dismutase activities of cerebral tissues, assayed by the chemiluminescence method, in the gerbil focal ischemia/reperfusion and global ischemia models

Superoxide dismutase is well known to act as an effective antioxidant enzyme against cellular damage caused by oxidative stresses including ischemia/reperfusion-induced cerebral injury. However, it is still controversial whether or not the activity of endogenous superoxide dismutase changes during cerebral ischemia and reperfusion. In order to elucidate this phenomenon, we assayed the superoxide dismutase activity in the cerebral tissues of gerbils using the chemiluminescence method with a Cypridina luciferin analog. This method was demonstrated to be a sensitive and specific assay for the enzymatic activity of superoxide dismutase in cerebral tissues, which was not subject to interference from proteins or ascorbate. After 3 h of focal and global ischemia, there were no changes in the cerebral tissue superoxide dismutase activities. After 24 h of reperfusion following 1 h of ischemia, the superoxide dismutase activity decreased only approx 20%, whereas the adenylate kinase activities, measured in the same cerebral tissues as those used for superoxide dismutase assay, started to decline 1 h after reperfusion commenced and were approx 50% of the control levels after 24 h. These results show that almost all the activity of endogenous superoxide dismutase is maintained and does not decrease significantly as a result of ischemia/reperfusion-induced cerebral injury.

Metastasis of malignant struma ovarii to the cranial vault during pregnancy.

Malignant struma ovarii is a rare type of ovarian teratoma; only 16 cases with distant metastases have been reported previously. We report an extremely rare case of malignant struma ovarii metastatic to the cranial vault, which developed during pregnancy. A 28-year-old woman in the 26th week of pregnancy, who had undergone resection of an ovarian tumor 3 years previously, noticed a mass in her left frontal region that had enlarged gradually in 6 months. Magnetic resonance imaging revealed a massive extradural tumor growing through the cranium. Under fetal heart monitoring, the patient underwent total resection of the tumor, including the adjacent cranial bone and dura, and a healthy infant was delivered at full term. Pathological examination showed that the tumor was a follicular adenocarcinoma. Because there was no abnormality in the patients thyroid gland, this tumor was considered to be a metastasis from the ovarian tumor, a malignant struma ovarii, resected 3 years previously. The management of brain tumor during pregnancy is also discussed.

Ruptured de novo aneurysm induced by ethyl 2-cyanoacrylate : Case report

OBJECTIVE AND IMPORTANCE We report a rare case of a ruptured de novo aneurysm induced by ethyl 2-cyanoacrylate. CLINICAL PRESENTATION A 44-year-old woman had undergone microvascular decompression for a right-sided facial spasm. The preoperative vertebral angiogram did not show any aneurysmal dilation. The right anteroinferior cerebellar artery, which was compressing the exit zone of the facial nerve, was detached and fixed to the dura mater with ethyl 2-cyanoacrylate. Nine years later, the patient suffered a subarachnoid hemorrhage caused by the rupture of a newly developed aneurysm of the right anteroinferior cerebellar artery. INTERVENTION The aneurysm was clipped 2 days after onset of the subarachnoid hemorrhage. It consisted of two bulges in the arterial wall on the proximal side of the meatal loop. One bulge was stuck to the dura mater of the pyramis by ethyl 2-cyanoacrylate, which had been used in the microvascular decompression 9 years previously. CONCLUSION This is the first reported clinical case of a de novo aneurysm induced by a cyanoacrylate adhesive. Ethyl 2-cyanoacrylate can damage the arterial wall and induce a de novo aneurysm.

Retraction of the Internal Carotid Artery and Measurement of the Regional Cerebral Blood Flow in Basilar Top Aneurysmal Surgery

In the surgery of the basilar top aneurysm, the internal carotid artery is often retracted to obtain a clear surgical field, which may lead cerebral ischemia. To prevent this the followings are noted: 1. The cross circulation especially through the anterior communicating artery is estimated before surgery, 2. The internal carotid artery is retracted at the elastic, less arteriosclerotic portion, 3. Cerebral protecting agents are administered, 4. A time keeper is arranged, 5. The duration of retraction is basically five minutes, 6. The regional cerebral blood flow and the EEG are monitored, 7. The retraction of the internal carotid artery must be extracted when there is a marked reduction of the regional cerebral blood flow, 8. The retraction of the internal carotid artery must be extracted when the slowing of the EEG is observed. In this report, a 74-year-old female patient with a basilar top aneurysm associated with a persistent primitive hypoglossal artery is described. The surgery was performed on day 5 after subarachnoid hemorrhage through a pterional approach by retracting the internal carotid artery. A thermal diffusion flow probe was used to monitor the regional cerebral blood flow during surgery. The regional cerebral blood flow was not reduced, or was reduced little, by the retraction of the internal carotid artery, and returned to the level before retraction by the extraction in the early phase. But later, after several retractions, the reduction of the regional cerebral blood flow became rapid by the retraction, and postischemic hyperemia was observed after the extraction. In this case the reduction of the regional cerebral blood flow was not so severe (less than 50%) that the operation could be continued safely, and the aneurysm was clipped successfully. The usefulness and significance of monitoring the regional cerebral blood flow during retraction of the internal carotid artery are discussed.