Sodium transport in the early postischemic period was studied using Mongolian gerbils with right common carotid artery ligation. [22Na]sodium chloride ([22Na]NaCl) was infused immediately after, 10 minutes before, and 4 hours before carotid ligation, and the 22Na distribution was measured in symptomatic animals by autoradiography 1 hour after ischemia. Regional cerebral blood flow was determined by [14C]iodoantipyrine autoradiography. The specific gravity of the brain was measured in symptomatic gerbils 1 and 2 hours after carotid ligation by a gradient column. There was a low uptake of 22Na in the ischemic core and a high uptake in the ischemic periphery when the tracer was given 10 minutes before or immediately after ischemia. In contrast, tracer given 4 hours before ischemia showed an increased radioactivity in both the ischemic core and periphery. It is suggested that increased sodium in the ischemic core is due to a decreased sodium clearance rate and increased sodium in the ischemic periphery is due to some active transport process.
The authors describe a new photodynamic therapy (PDT) method for malignant brain tumors. Pheophorbide α (Ph-a), the photosensitizer, has low toxicity, causes no skin sensitization and is activated with an acoustic Q switched neodymium yttrium-argon-garnet (Nd:YAG) laser which achieves deep tissue penetration. The Ph-a distribution in Fisher 344 (F344) rats bearing rat T9 glioma at 24 hours after intravenous injection was very low in the normal brain tissue, but significantly higher in the T9 glioma giving a tumor to normal brain tissue concentration ratio of 7.5:1. The in vitro survival rate of T9 glioma cells pretreated with Ph-a was 68.8 ± 5.4% after laser irradiation for 20 minutes, significantly lower than in the control groups. This indicates that Ph-a was activated with the acoustic Q switched Nd:YAG laser causing the photodynamic effect. The survival rate after Ph-a pretreatment and laser irradiation in a waterbath at 44.0°C was further reduced to 15.8 ± 3.3%. In vivo PDT studies using T9 glioma cells inoculated into the dorsal region of F344 rats showed tumor eradication in four of six rats. The combination of PDT and laser hyperthermia produced tumor eradication in all six rats. The combination of PDT and hyperthermia is a promising method for tumor treatment.
The critical value and duration of intracranial pressure (ICP) causing cerebral function damage was evaluated in six head injury patients by monitoring the first negative cortical component (N20) of the somatosensory evoked potential (SEP). The SEP was elicited by stimulating the median nerve, and N20 (C3' or C4'-Fz on the affected side) and N13 (C2S-Fz) were monitored serially with a signal processor. The auditory brainstem response (ABR) was simultaneously recorded on the affected side (A1 or A2-Cz). A reversible loss of N20 occurred 7 times in six cases. In all cases, the N20 was restored by emergency decompression or hyperosmolar therapy. The minimum ICP at which N20 disappeared was 30 mmHg, and the N20 was restored when decompression was performed within 4.5 hours. However, when the disappearance persisted for more than 1.5 hours, the N20 latency was markedly prolonged after restoration. These changes appeared before the ABR showed definite abnormalities. These results show that the cerebral function may be damaged when ICP exceeds 30 mmHg, and that emergency decompression is required within 4.5 hours, preferably within 1.5 hours, to restore cerebral function. This critical ICP and duration should be of clinical value in patient management.
A rare aneurysm in the horizontal segment (A) of the right anterior cerebral artery was found in a 58-year-old male presenting with subarachnoid hemorrhage. No obvious bleeding source was observed on the day of onset, but 7 days later, a definite diagnosis was made based on the discovery of cerebral vasospasm by a repeat angiogram. The aneurysm was clipped via the right frontotemporal approach 15 days after onset. He suddenly developed neurological symptoms such as consciousness disturbance, right hemiplegia, and aphasia on the 4th postoperative day, when remission of the cerebral vasospasm was confirmed by transcranial Doppler ultrasound examinations and cerebral angiography. The ischemic symptoms were probably due to cerebral embolus caused by intraluminal thrombi, which had formed during the maximum phase of vasospasm and became detached during the remission phase.
A 26-year-old male with an intracranial teratoma, metastasizing from a testicular yolk sac tumor refractory to cis-diamminedichloroplatinum (CDDP), vinblastin, and bleomycin (PVB) therapy, was successfully treated with a combination of etoposide (VP-16), CDDP, and ACNU (salvage chemotherapy). Emergency surgery for subcortical hemorrhage discovered the metastasis, diagnosed as a yolk sac tumor. CDDP chemotherapy failed to prevent recurrence, and total removal was impossible due to subdural invasion. He underwent radiation therapy and salvage chemotherapy. A third operation found only scar tissue. Maintenance salvage chemotherapy was continued. He was doing well 30 months after the first operation.
The authors report a case of epithelial cyst, which recurred 32 years after the initial surgical treatment. Computed tomography showed no abnormality, but magnetic resonance (MR) imaging clearly demonstrated a well-demarcated mass in the prepontine cistern, extending into the fourth ventricle. The lesion showed extreme hyperintensity compared with the surrounding brain on both the T1- and T2-weighted images. The ultrastructural features of the cyst suggested an endodermal origin. MR imaging and electron microscopy are essential for correct diagnosis and exact pathogenetic identification of intracranial cystic lesions.
The authors report a case of sinus pericranii in a 22-year-old female presenting with severe headache, vomiting, bradycardia, and bradypnea following excessive distention of the tumor. After tumor removal, the symptoms were completely relieved. The symptoms were thought to be due to transient impairment of blood flow in the superior sagittal sinus.
We present a rare case of unilateral internal carotid artery (ICA) hypoplasia associated with arterial anomalies in the circle of Willis. The ipsilateral middle cerebral artery was supplied via anomalous arteries from the posterior cerebral artery and the ICA. The ipsilateral common carotid artery also originated from the anomalous brachiocephalic trunk. The etiology of the hypoplastic ICA is uncertain, but the associated multiple vascular anomalies support the congenital origin.
A 49-year-old female with subacute myelopathic symptoms due to thickened cervicothoracic yellow ligament and abnormal epidural fibrous tissue is reported. Myelography showed a complete block at the Th3 level. Magnetic resonance imaging demonstrated an extra-axial mass lesion in the spinal canal at the cervicothoracic junction causing the spinal cord compression. Laminectomy with resection of the lesion resulted in good neurological recovery. Histological examination revealed a thickened ligamenta flava and abnormal epidural fibrous tissue without calcification foci.