The present study evaluated whether technetium-99m sestamibi (99mTc-MIBI) single photon emission computed tomography (SPECT) characteristics of intracranial meningioma are correlated with the histological malignancy, proliferative potential, and P-glycoprotein (Pgp) expression, encoded by the multidrug resistance gene-1 (MDR-1) messenger ribonucleic acid (mRNA). Twenty-one patients with intracranial meningiomas, including 17 benign and four nonbenign meningiomas, underwent 99mTc-MIBI SPECT imaging at 15 minutes (early) and 3 hours (delayed) after injection. The tumor-to-normal pituitary gland ratio was calculated on both early (ER) and delayed (DR) images. Retention index (RI) was calculated using the following formula: (DR - ER)/ER × 100%. Meningioma specimens were examined by immunohistochemistry using anti-Pgp and MIB-1 monoclonal antibody. MDR-1 mRNA expression was also investigated using reverse transcription-polymerase chain reaction assay. 99mTc-MIBI was highly accumulated and retained in the tumors. 99mTc-MIBI SPECT findings were not related to MIB-1 labeling index. 99mTc-MIBI SPECT RI of the Pgp-positive group (-9.12 ± 22.27%) was significantly lower than that of the Pgp-negative group (28.79 ± 22.80%) (p = 0.0016). No significant difference was seen in ER and DR between the positive and negative groups. These results show that 99mTc-MIBI may not be useful for determining proliferative potential and histological malignancy, but could predict anticancer drug resistance related to the expression of MDR-1 mRNA and its gene product Pgp in patients with intracranial meningiomas.
The clinical features and endoscopic findings were investigated in 20 patients with isolated lateral ventricle treated by neuroendoscopic septostomy to establish cerebrospinal fluid communication and open an isolated ventricular compartment. The endoscopic procedure was incomplete because of thickened septum pellucidum and insufficient working space in two adults with postmeningitic hydrocephalus. Two children underwent second septostomy. In all other cases, results were good and there were no complications related to endoscopic procedures. Endoscopic septostomy is less invasive and has few complications. Intraoperative navigation and the biportal approach may be required in difficult cases with multiple septum formation and severe postmeningitic hydrocephalus. Adequate stomal size is required in high-risk groups including children under 2 years of age.
The risk of epileptic seizures after craniotomy is extremely important but the incidence of postoperative epilepsy varies greatly, depending on the patient's conditions such as primary diseases, severity of surgical insult, and pre-existing epilepsy. Animal studies suggest that neurosurgical insults lead to seizures by two different mechanisms: One mechanism is mediated by free radical generation and the other by impaired ion balance across the cell membrane caused by ischemia or hypoxia. Conventional antiepileptic agents such as phenytoin, phenobarbital, carbamazepine, and valproic acid are promising for the prevention of early seizures, but the effect in preventing postoperative epilepsy is still controversial. Studies on the prophylactic effect of newer antiepileptic agents in craniotomized patients were very limited. Zonisamide, an antiepileptic agent with antiepileptogenic, free radical scavenging and neuroprotective actions in experimental animals, showed promising effects against postoperative epilepsy in a randomized double blind controlled trial. Prophylactic treatment for craniotomized patients significantly prevented the development of partial seizures during the follow-up period. Most recent studies have not supported the prophylactic use of antiepileptic agents in craniotomized patients, but further studies are required.
A 50-year-old previously healthy woman presented with symptoms of subarachnoid hemorrhage. Initial cerebral angiography did not determine the site of the hemorrhage but repeat angiography disclosed an aneurysm-like image, probably in the medial posterior choroidal artery (PChA). Selective angiography performed using a microcatheter technique clearly revealed two medial PChAs arising from the ambient segment of the posterior cerebral artery. One medial PChA included an aneurysm on the cisternal segment, then ran peripherally to supply the plexus in the roof of the third ventricle. The other medial PChA mainly supplied the pineal body, tegmentum of the midbrain, and posterior border of the thalamus. The patient underwent open surgery following the zygomatic approach and the parent artery was clipped. She was discharged without neurological deficits or compromise of higher brain functions.
A 66-year-old man presented with clival chordoma associated with subarachnoid hemorrhage. Computed tomography showed subarachnoid hemorrhage in the right ambient cistern and a well-enhanced tumor in the petroclival region. Surgical exploration performed on the day of admission showed a clot in the tumor. The tumor was totally removed. Histological examination showed hemorrhage between the tumor and the dura. The diagnosis was clival chordoma. Subarachnoid hemorrhage in chordoma seems to occur by spreading of intratumoral hemorrhage into the subarachnoid space due to dural invasion.
A 67-year-old man died of subarachnoid hemorrhage (SAH) resulting from dissection of the distal part of the anterior cerebral artery (ACA). A saccular aneurysm in the anterior communicating artery had ruptured and was successfully clipped on Day 0. The patient recovered consciousness after surgery but his condition deteriorated due to another SAH on Day 1. A second surgical procedure disclosed bleeding from a laceration in the opposite wall of the ACA distal to the clipped aneurysm. Histological examination of the autopsy specimens revealed damage to the internal elastic lamina and inflammatory infiltration of leukocytes. The fatal dissection may have resulted from atherosclerosis, hemodynamic stress caused by hypertension, or trauma due to surgical manipulation.
Two cases of very rare intramedullary spinal cord metastasis from colon carcinoma and renal carcinoma were treated primarily by microsurgical excision. A 44-year-old female presented with colon carcinoma metastasis manifesting as complete neurological deficit. She had undergone colon resection 2 years previously for colon carcinoma. The tumor was excised by microsurgery with megadose steroid therapy but she remained paraplegic. A 43-year-old man presented with renal carcinoma metastasis manifesting as incomplete neurological deficits. He had undergone nephrectomy one year previously for renal carcinoma. The tumor was removed by microsurgery. He made a remarkable neurological recovery and became ambulatory after physical therapy.
An 11-year-old male presented with subependymal giant cell astrocytoma (SEGA) without other manifestations of tuberous sclerosis such as facial angiofibroma, epilepsy, or mental retardation. The diagnosis was “possible tuberous sclerosis complex” (TSC). Total resection of the tumor was performed. Immunohistochemical study revealed positive tuberin expression. In general, loss of tuberin is thought to be critical to the TSC phenotype. Our case demonstrated clear expression of tuberin in the SEGA specimen.
A 35-year-old male presented with a variant of neurocutaneous melanosis with leptomeningeal malignant melanoma. He had three pigmented nevi from birth. He suffered diplopia followed by headache. T1-weighted magnetic resonance (MR) imaging revealed hydrocephalus and a small linear hyperintense lesion in the right frontal cortex. Several parts of the cortical sulci and the brain surface were slightly enhanced by gadolinium. Ventriculoperitoneal shunting was performed and extensive pigmented leptomeninges were recognized. Open biopsy established the diagnosis of leptomeningeal malignant melanoma. Combined chemoimmunotherapy was repeated every other month with monitoring of the 5-S-cysteinyldopa (5-S-CD) level in the cerebrospinal fluid (CSF). The 5-S-CD level decreased after each treatment, but the basal level steadily increased prior to the next treatment. Two years after the onset, he showed paraplegia caused by an extramedullary mass at the T-6 level. MR imaging showed that melanoma had involved the entire subarachnoid space including the whole spine. He underwent emergent removal of the spinal tumor and showed transient marked improvement. Further intensive chemotherapy was given. However, he died 31 months after the onset of massive proliferation of intracranial leptomeningeal melanoma. Measurement of CSF 5-S-CD levels is valuable for evaluating the therapeutic efficacy and for monitoring the progression of melanoma.
A 30-year-old male patient presented with chronic spontaneous cerebrospinal fluid (CSF) rhinorrhea. He had sustained a mild head injury in childhood. Magnetic resonance imaging of the brain showed aqueductal stenosis associated with moderate supratentorial hydrocephalus, and erosion of the cribriform plate. Following insertion of ventriculoperitoneal shunt, the CSF rhinorrhea completely ceased and no direct repair of the CSF fistula was necessary. Long-standing spontaneous CSF rhinorrhea indicates the possibility of concurrent intracranial pathology, such as aqueductal stenosis.