The effect of ionizing radiation on the expression of immunohistochemical proliferation markers was examined in the rat pituitary gland. Rats were irradiated in the pituitary region with a dose of 40 Gy, or were sham-irradiated as controls. Bromodeoxyuridine (BrdU) was given to the rats after one week, either one hour (Br-1 group) or 17 hours (Br-17 group) before perfusion fixation. Immunohistochemical staining for BrdU, topoisomerase II-alpha (TopoII), Ki-67 (MIB-5), p21WAF1/Cip1 (p21), and p27Kip1 (p27) was performed. Apoptotic cells were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling method. The mean BrdU labeling index (LI) and MIB-5 LI were significantly higher in the irradiated rats than in the sham rats in the Br-1 group. TopoII LI was higher in the irradiated rats than in the sham rats, although not significantly. p27-positive cells decreased in irradiated rats, but p21-positive cells increased more than in the sham rats. The number of apoptotic cells increased significantly after radiation. BrdU LIs were lower in the irradiated rats than in the sham rats in the Br-17 group. A few small BrdU-positive fragments with apoptotic features were phagocytosed in the anterior lobe cells. These results indicate that some “immunohistochemically proliferating cells” subsequently undergo apoptosis in the irradiated pituitary gland. The values of proliferative indices should be cautiously interpreted after irradiation of tissue.
B-flow ultrasonography can directly visualize blood streams by reflecting the intravascular red blood cells, and so can detect turbulent flow in vessels. B-flow sonography was used to evaluate flow abnormalities in patients with cervical carotid artery stenosis, and to investigate the mechanism of large embolus formation that may cause distal arterial occlusion. Twenty-two patients with ≥60% stenosis of the cervical carotid artery excluding cardiovascular embolism were examined by B-flow and color Doppler sonography. Two patients had distal embolism as revealed by digital subtraction angiography, 16 patients had lacunar infarction, and four patients had transient ischemic attacks. B-flow sonography demonstrated reverse flow at the poststenotic site in patients with ≥70% stenosis. Increased echogenicity at the site of the stenosis was seen in patients with at least 80% stenosis. Prestenotic reverse flow was seen in nine patients with ≥85% stenosis. The two patients with distal embolism had decreased echogenicity and flow velocity, and diastolic flow was absent. B-flow sonography could detect various turbulent flow patterns and changes in echogenicity associated with cervical carotid artery stenosis. Prestenotic reverse flow and decreased flow velocity may be potential causes of distal embolism. B-flow sonography is a useful method for the evaluation of flow abnormality in patients with carotid artery stenosis.
The characteristics of seizures associated with parietal lobe epilepsy were investigated in six consecutive patients with medically intractable epilepsy due to parietal lobe lesions. Intracranial electrode recordings were retrospectively reviewed to investigate the seizure onset symptoms and spreading patterns associated with the disorder. All six patients underwent implantation of subdural or depth electrodes and subsequent video/electroencephalography monitoring. Common symptoms included motionless stare, contralateral eye deviation, and head turn. Tonic posturing, contralateral sensory disturbance, and motor weakness were also seen. Asymmetrical generalized tonic and clonic seizures were seen in all six patients. All seizure activities began in the parietal lobe harboring the lesions, and then spread immediately to the adjacent lobes in most seizures, where the clinical symptoms were produced. The parietal lobe is a pure generator of seizures, whereas most clinical symptoms originate from adjacent lobes following seizure onset. No apparent specific symptoms other than sensory disturbance arising from the parietal lobe proper were recognized. Regardless of clinical symptoms, the seizure onset occurred in the parietal lobe harboring the lesion.
A 21-year-old woman with severe mitral valve regurgitation due to infectious endocarditis was transferred to our institute in a deep coma with intracerebral hemorrhage and acute subdural hematoma. She had no history of head injury. Brain computed tomography revealed left frontoparietal intracerebral hematoma and adjacent acute subdural hematoma that were evacuated on the day of admission, but the distal middle cerebral artery (MCA) aneurysm remained undetected. Follow-up cerebral angiography demonstrated the distal MCA aneurysm, which had enlarged by 25% at 2 weeks following the first operation. The aneurysm originated from a branch of the angular artery and was successfully resected on Day 22. Histological examination of the aneurysm section showed no infectious nature, but the final diagnosis was infectious intracranial aneurysm based on the presence of infectious endocarditis.
A 49-year-old female with a history of systemic hypertension and diabetes mellitus suffered transient right hemiparesis. Carotid angiography with arch-aortography detected severe stenosis of the proximal portion of the left common carotid artery. The left carotid bifurcation was surgically exposed and retrograde catheterization was performed to approach the proximal common carotid artery stenosis. The lesion was dilated with a balloon catheter and successfully stented without complications. The left internal carotid artery was clamped during the procedure to avoid embolism. Retrograde carotid stenting for stenosis of the proximal common carotid artery is a safe and effective alternative to conventional surgery in selected patients.
A 67-year-old woman presented with a ruptured aneurysm of the left internal carotid artery bifurcation. Three-dimensional computed tomography angiography (3D-CTA) demonstrated the first segment of the basal vein of Rosenthal passing in front of the internal carotid artery and the anastomosis with the cavernous sinus, the partially hypoplastic second segment, and the superficial sylvian vein entering the lateral side of the sphenoparietal sinus. Dissection of the sylvian fissure toward the distal direction enabled transfer of the superficial sylvian vein to the temporal side, but the bridging vein had to be sacrificed to secure adequate operating space. Postoperative CT demonstrated hemorrhagic infarction at the left caudate head and surrounding region. Postoperative venous infarction is not an uncommon complication of various approaches. 3D-CTA can provide important information about the venous anatomy indispensable for avoiding postoperative venous infarction.
A 21-year-old male patient presented with a rare cerebellopontine angle medulloblastoma manifesting as cerebellar and long tract involvement signs and symptoms. The clinical and radiological characteristics of the lesion were similar to extraaxial lesions of cerebellopontine angle. The histological diagnosis of the lesion was medulloblastoma. Surgery achieved partial removal and was followed by radiotherapy and chemotherapy. The patient remained well after 18 months. Medulloblastoma of the cerebellopontine angle is a relatively rare clinical entity and may occur as a dural-based extraaxial mass.
A 33-year-old pregnant woman presented with intratumoral hemorrhage in an astrocytoma of the left optic nerve and chiasm manifesting as poor vision in her left eye. Visual examination found no light perception in the left eye and deteriorated acuity with temporal hemianopsia in the right eye. Computed tomography demonstrated a round high-density mass in the suprasellar region. T1-weighted magnetic resonance (MR) imaging showed the center of the mass as mildly hypointense and T2-weighted MR imaging as hypointense. Both T1- and T2-weighted MR imaging showed the rim of the mass as hyperintense. She delivered a healthy baby by cesarean section. A left frontotemporal craniotomy was then performed. Incision of the lateral surface of the left optic nerve revealed clotted blood from the left optic nerve and the left side of the chiasm. No vascular malformation was noted in the hematoma cavity. Histological examination revealed a neoplasm composed of well-differentiated astrocytic cells. No Rosenthal fibers were identified. The patient made an uneventful postoperative recovery. Her right visual acuity returned to normal, but the temporal hemianopsia in the right eye and the blindness in the left eye persisted. Gliomas of the anterior visual pathways are rare, especially in adults. The hemorrhage may have been caused by the hypercoagulable state associated with pregnancy. Optic nerve astrocytic glioma with intratumoral hemorrhage should be considered in the differential diagnosis of suprasellar hematoma.
A 6-year-old boy presented with mental disturbance and progressive left hemiparesis. Magnetic resonance imaging demonstrated large intracranial mass lesions with ring-like enhancement. His neurological condition deteriorated rapidly. Open biopsy via craniotomy was performed under the suspicion of tumor. Histological examination showed massive demyelination and axon preservation, but no tumor cells. The diagnosis was myelinoclastic diffuse sclerosis (MDS). He was treated with high-dose methylprednisolone and improved dramatically. MDS is a rare demyelinating disorder of the central nervous system that affects mainly children and may mimic a brain tumor. MDS must be included in the differential diagnosis in young patients with a brain tumor with atypical radiological appearance.
A 71-year-old male presented with multiple central nervous system tuberculomas including spinal intramedullary tuberculoma manifesting as occipitalgia and left hemiparesis. He had received medical treatment for lung and testis tuberculosis. Magnetic resonance imaging revealed an intramedullary lesion at the C-2 level as well as multiple small extramedullary and intracranial lesions. His neurological symptoms gradually worsened despite intensive antituberculous therapy. The C-2 intramedullary lesion responsible for left hemiparesis was surgically extirpated. Postoperatively, his neurological symptoms improved gradually, and no recurrence was evident at the resected site. Surgical intervention is mandatory in patients with intramedullary tuberculoma if neurological symptoms deteriorate or lesions enlarge despite continuous antituberculous therapy.