Evaluation of the cerebral circulation dynamics in patients with stroke soon after onset is extremely important for planning the optimum treatment. Perfusion computed tomography (CT) was evaluated in 118 patients with stroke within 10 hours of onset in whom initial CT showed no ischemic change. The mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume (CBV) perfusion CT maps were visually evaluated in three slices covering the body of the lateral ventricle, the basal ganglia, and the pons, and the ratios of the values in regions of interest (ROIs) in the ischemic lesion and the symmetrical location in the opposite hemisphere were calculated (ROI ratio of regional (r) MTT, rCBF, and rCBV). The location of occlusion was confirmed by angiography performed on the same day in 106 cases and the location of infarction by later magnetic resonance (MR) imaging. MTT maps correctly identified 44 of 46 cases of ischemia in the carotid system, 20 of 29 cases of ischemia in the vertebrobasilar system, and 11 of 35 cases of ischemia in perforator regions. Eight cases could not be identified by perfusion CT, angiography, or MR imaging. The ROI ratios at the upper boundary of infarction (n = 18) were: rCBF 0.574 ± 0.220 (mean ± SD) and rCBV 0.972 ± 0.276, and at the lower boundary of non-infarction (n = 24) were: rCBF 0.504 ± 0.247 and rCBV 0.815 ± 0.169; showing a statistical significance of p = 0.348 for CBF and p = 0.026 for CBV (unpaired t-test). The perfusion CT MTT maps correlated well with the angiographical findings for the carotid system, but poorly for the vertebrobasilar system and the perforator regions. A rCBF ratio of 0.5 and rCBV ratio of 0.9 were established for the boundaries of ischemia.
The effect of edaravone as an inhibitor of ischemic brain damage in addition to routine treatment was retrospectively examined in 70 patients with lacunar infarction who were admitted within 24 hours of symptom onset. Clinical status was assessed using the National Institutes of Health Stroke Scale (NIHSS). The modified Rankin Scale (MRS) was used to assess clinical outcomes at 3 months after onset, with a good outcome defined as MRS score ≤2. Risk factors were also evaluated, including evidence of hypertension, diabetes mellitus, hyperlipidemia, coronary heart disease, and a history of smoking longer than 2 months. The probability of a good outcome and independence at 3 months was assessed by backward stepwise logistic regression analysis based on the maximum likelihood ratio. Administration of edaravone yielded an odds ratio with multivariate adjustment of 6.49 (95% confidence interval, 1.35 to 50.32; p < 0.05) for a good outcome at 3 months. Higher baseline NIHSS score and higher age also adversely affected the outcome at 3 months (p < 0.005). Administration of edaravone improves the outcome of patients with lacunar infarction.
This study investigated whether the optic nerve evoked potential (ONEP) elicited by electrical stimulation of the optic nerve can serve as a reliable intraoperative indicator of visual function. In the experimental study, two silver-ball stimulating electrodes were placed on the dog optic nerve adjacent to the apex of the orbit and one recording electrode was placed on the optic nerve near the chiasm. The nerve was stimulated with 0.1 to 10 mA rectangular pulses. Stable and reproducible ONEPs were obtained. The ONEPs were not influenced by electromyographic potentials and were recorded more clearly on the optic nerve than on the surrounding tissue. Stepwise incremental transection of the thickness of the nerve resulted in incremental amplitude reduction proportional to the transected area. No response was recorded after complete sectioning of the nerve. In the clinical study, recordings were obtained from 15 patients after craniotomy to treat parasellar tumors or cerebral aneurysms. Reproducible ONEPs were recorded intraoperatively from the electrode placed on the optic nerve near the chiasm in 14 of 15 patients. In the remaining patient, the ONEP, recorded only after tumor removal because the optic nerve was stretched and extremely thin, was remarkably small and the patient developed unilateral blindness postoperatively. These experimental and clinical results suggest the possibility of intraoperative monitoring of visual function in patients undergoing craniotomy for the treatment of lesions near the optic nerve.
A 59-year-old healthy woman presented with sudden onset of severe headache. Computed tomography and digital subtraction angiography (DSA) demonstrated subarachnoid hemorrhage (grade I according to the Hunt and Hess classification) due to a ruptured small right posterior cerebral artery (PCA) aneurysm. The ruptured PCA aneurysm was completely embolized with three Guglielmi detachable coils (GDCs). However, follow-up DSA 3 months after the initial coiling confirmed refilling of the aneurysm. The aneurysm was successfully re-embolized with two GDCs. Follow-up DSA 10 months later revealed regrowth of the aneurysm. Surgical clipping was performed without compromising the parent vessels. Long-term angiographic follow up is necessary even in patients with small saccular aneurysms which are apparently completely embolized by endovascular coil treatment.
A 62-year-old woman presented with right hemifacial spasm persisting for 6 months. Brain magnetic resonance imaging and digital subtraction angiography showed a wide-neck aneurysm of the intracranial portion of the right vertebral artery. The patient underwent endovascular trapping of the aneurysm by coil embolization of the parent vessel on both sides of the aneurysm. The patient experienced gradual disappearance of the hemifacial spasm within 3 months. No relapses occurred during a follow-up period of 3 years. Magnetic resonance imaging revealed shrinkage of the vertebral artery aneurysm which had compressed the facial nerve. Endovascular trapping of a vertebral artery aneurysm can be used to treat hemifacial spasm caused by an aneurysm instead of surgical microvascular decompression.
A 41-year-old woman presented with a small occipital arteriovenous malformation (AVM) manifesting as headache. Cerebral angiography showed an AVM in the right occipital lobe fed by the right temporooccipital artery and draining into the superior sagittal sinus and right transverse sinus. Single photon emission computed tomography showed the steal phenomenon in the ipsilateral temporal cortex fed by the main feeding artery preoperatively, and hyperperfusion in the same cortex after removal of the AVM. Postoperative systolic blood pressure was maintained between 100 and 120 mmHg to avoid disastrous hemorrhagic complications. Cerebral blood flow evaluation before and after surgery is important to avoid postoperative disastrous complications even in patients with small AVM.
A 67-year-old man presented with left lower cranial nerve paresis and dysfunction of the left cerebellar hemisphere 4 years after amputation of the left lower leg because of clear cell chondrosarcoma (CCC). Neuroimaging studies showed an osteolytic extradural mass with homogeneous enhancement in the left posterior fossa. Bone scintigraphy disclosed a single high-uptake lesion at the same site. The tumor was removed totally via a left suboccipital craniotomy. Histological examination found mainly clear cells arranged in a microlobular pattern separated by thin fibrovascular stroma. The nuclei were regular with few mitotic figures. Immunohistochemical staining showed the tumor cells reacted intensely for both S-100 protein and vimentin. Osteoclast-like multinucleated giant cells were found at the periphery of the lobules. The primary tumor showed the same findings and the metastatic tumor manifested no malignant change. The histological diagnosis was metastatic CCC. CCC is a very rare neoplasm with slow growth and low-grade malignancy. Distant metastasis is rare but can occur in the skull base bone despite radical resection of the primary tumor. Osteolytic findings of homogeneous enhancement on magnetic resonance imaging and a high uptake on bone scintigraphy are indicative of metastatic tumor from previous CCC.
A 63-year-old woman presented with a rare case of primary solitary fibrous tumor (SFT) occurring in the extramedullary thoracic spinal cord. T1-weighted magnetic resonance (MR) imaging showed the tumor as a mildly hypointense area with homogeneous enhancement by gadolinium. T2-weighted MR imaging showed a hypointense mass with peritumoral edema. The tumor arose from one of the posterior spinal roots, with no attachment to the dura. The tumor was clearly circumscribed from the surrounding cord tissue and easily removed. Histological examination showed the tumor predominantly consisted of spindle cells separated by abundant collagen matrix fibers. Tumor cells were strongly positive for vimentin and CD34, but negative for glial fibrillary acidic protein, S-100 protein, epithelial membrane antigen, myelin basic protein, and keratin. SFT should be considered in the differential diagnosis of spindle cell central nervous system neoplasms, although SFT is extremely rare in the spinal cord.
A 30-year-old man presented with an intradural spinal teratoma with thickened filum terminale manifesting as urinary and sexual disturbances, and low back pain persisting for 4 years. Spinal magnetic resonance imaging revealed thickened filum terminale containing a heterogeneously enhanced intradural lesion extending from the L-3 to L-4 levels and in contact with the conus medullaris. The filum terminale was incised and the tumor was totally resected. The histological diagnosis was mature teratoma consisting of three germ cell layers. The patient’s complaints had completely resolved 6 months later.
A 24-year-old woman presented with a lumbar spinal osteoblastoma manifesting as a 5-year history of low back pain radiating to the left foot. Neuroimaging showed suspicious hypertrophy of the left L4-5 facet which transformed in 3 years to an expansile mass lesion that compressed the dura mater and neural structures. Primary benign bone tumors such as osteoblastoma and osteoid osteoma should be considered in the differential diagnosis of back pain and the patients should be followed up carefully.