Based on our experiences with medico-legal autopsies, we analyzed traumatic injury of the vertebrobasilar artery (VBA) in traffic accident victims. VBA rupture occurred in six cases with traumatic medullary lesions, but in none with cervical cord injury. A relatively small external force applied to the head or neck can induce isolated traumatic subarachnoid hemorrhage (SAH), which accounts for approximately 11% of fatal head injuries. We examined the relationship between site of impact and site of vascular injury in 16 cases of isolated traumatic SAH. The results showed that the vertebral artery (VA) on the side of impact tended to be longitudinally injured in victims experiencing an external force equivalent to that of a fist punch to the head or face. There was no clear relationship between the site of impact and the site of vascular injury in victims who had sustained an external force greater than that of a fist punch. However, our results suggest that an external force causing rotation of the head was likely to cause tearing of the artery. In cases in which an external force equivalent to that of a fist punch was applied to the head, a raised blood alcohol level was a significant risk factor for artery rupture. Furthermore, a difference in the diameters of the left and right VAs was a risk factor for artery rupture. To determine why the VA, the most frequent site of arterial dissection, is also frequently the site of injury, we histologically examined normal and dissected VBAs. We also discuss medico-legal issues of the causal relationship between external force applied and rupture or dissection of the VA.
The incidence and characteristics of microbleeds in hemodialysis (HD) patients were investigated to elucidate the clinical significance with T2*-weighted gradient-echo magnetic resonance (MR) imaging. The 57 patients with chronic renal failure maintained by HD had no previous history of stroke. The control group consisted of 53 patients without previous history of stroke or chronic renal failure. The incidence and the number of microbleeds were assessed in the HD and control groups. The findings of microbleeds with T2*-weighted gradient-echo MR imaging were compared with those of T1- and T2-weighted MR imaging in HD patients. The incidence of microbleeds was significantly greater in the HD patients compared with the control patients. T2*-weighted gradient-echo imaging revealed a total of 44 microbleeds in 11 HD patients. T2-weighted imaging demonstrated 13 of 44 microbleeds as hyperintensity, whereas T1-weighted imaging demonstrated 12 lesions as hypointensity. T2- and T1-weighted imagings did not demonstrate any findings in 31 and 32 lesions, respectively. T2*-weighted gradient-echo MR imaging is effective to detect microbleeds which may be a predictor of intracerebral hemorrhage in HD patients and should be included in the protocol for the study of cerebrovascular disease, because T2- and T1-weighted MR imaging recognizes microbleeds as lacunar infarction.
The correlation between volume embolization ratio (VER), the percentage of aneurysm volume occupied by coils, and aneurysm stability after endovascular treatment with platinum coils was studied in 86 patients who underwent embolization of 88 cerebral saccular aneurysms with standard platinum coils between March 1997 and January 2003. Radiographic follow up was possible of 62 aneurysms with greater than 70% obliteration on immediate post-procedure angiograms for more than 6 months. Immediate post-procedure evaluation found that 12 of 14 small (<4 mm), 12 of 38 medium (4-<10 mm), and two of 10 large (≥10 mm) aneurysms had high (≥25%) VER. In addition, the VER was high in 22 of 40 aneurysms with small (<4 mm) and four of 22 with wide necks (≥4 mm). Evaluation of 57 aneurysms at 6 months after coil embolization found recanalization in two of 25 aneurysms with high VER and 21 of 32 with low (<25%) VER, indicating that aneurysms with high VER are significantly more stable than those with low VER (p < 0.01). VER strongly affects aneurysm stability, so high VER is desirable and a useful predictor of aneurysm stability.
Silicone models of cerebral aneurysm and stroke pathology were produced by copying the images of clinical cases to evaluate the simulation of endovascular procedures. Conventional silicone models, silicone suture models made from separate aneurysm sac and parent artery sutured together, and animal vascular models made from vessels obtained from pigs were made. The models were incorporated in the training system for simulation of endovascular procedures under digital subtraction angiography control using a portable angiography system. The conventional silicone models provided very close reproduction of the aneurysm and vessels, even the fine branches. However, greater resistance or impact was felt, especially when passing the device through curved vessels. Stroke models were insufficiently dilated by percutaneous transluminal angioplasty or stenting. The silicone suture model was useful to avoid damage to models of giant aneurysm or models with small orifices during the lost wax procedure, whereas the projection of domes was somewhat inaccurate. The animal vascular model could not provide accurate aneurysm shape and vessel diameter, although the feel during manipulation was much more realistic.
A previously healthy 61-year-old man presented with basal ganglia hemorrhage caused by rupture of a small aneurysm arising from the distal lenticulostriate artery associated with moyamoya-like disease and manifesting as left hemiparesis and dysarthria. The patient underwent frontotemporal craniotomy. Neck clipping of the aneurysm was performed through the hematoma cavity. He was transferred for rehabilitation with left hemiparesis. Three-dimensional computed tomography angiography was very useful for preoperative planning and evaluation of the anatomical correlation between the aneurysm and the hemorrhage.
A 29-year-old female presented with Basedow’s disease manifesting as sudden vomiting, diarrhea, fever over 38°C, transient aphasia, and numbness in her extremities. These symptoms were considered due to cerebral ischemia at a local clinic. Magnetic resonance angiography indicated stenosis of the bilateral distal internal carotid arteries and the bilateral proximal anterior cerebral and middle cerebral arteries. Thyroid swelling and exophthalmos were observed. She was transferred to our hospital. Endocrine function tests showed hyperthyroidism. The diagnosis was Basedow’s disease. Her symptoms disappeared after receiving intravenous drip infusion of fluid replacement, and antithyroid and antiplatelet medication. After she became euthyroid, cerebral angiography and magnetic resonance angiography revealed improvement of the stenosis of the cerebral arteries. Stenosis of the terminal portion of the internal carotid artery associated with Basedow’s disease is extremely rare. Conservative treatment mainly including antithyroid medications for Basedow’s disease, and antiplatelet drugs and intravenous replacement fluid for the ischemic manifestations should be the first choice of treatment unless immediate vascular reconstruction is necessary.
A 10-month-old boy presented with traumatic internal carotid artery (ICA) occlusion caused by blunt injury after falling from a baby carrier attached to a standing bicycle. Physical examination found bruises on the scalp in the right temporal region and the right shoulder, but no wound in the neck. Chest radiography showed a right clavicular fracture. He developed left hemiparesis at 19 hours after the injury. Computed tomography revealed cerebral infarct and angiography showed cervical ICA occlusion. Conservative therapy with hemodilution was given under a diagnosis of cervical ICA occlusion caused by extension and rotational head injury. Traumatic cervical ICA occlusion due to blunt injury is not uncommon in adults, but extremely rare in infants. We would like to emphasize the dangers of leaving a baby unattended in a carrier attached to a standing bicycle.
A 75-year-old woman presented with intracranial B-cell lymphoma associated with Behcet’s disease manifesting as headache and dizziness. She had been treated with prednisolone for 17 years, and colchicine for 4 years under a diagnosis of incomplete Behcet’s disease. Computed tomography revealed a 4-cm high density mass surrounded with diffuse edema in the right frontal lobe. Surgery removed a discolored red mass together with hematoma. The histological diagnosis was B-cell type malignant lymphoma. Malignant lymphoma is rarely associated with Behcet’s disease, as only 10 cases have been reported.
A 64-year-old woman presented with a rare anaplastic ganglioglioma in the right cerebellopontine angle manifesting as dizziness persisting for 2 weeks. Preoperative magnetic resonance (MR) imaging revealed a partially enhanced cystic lesion of the right cerebellopontine angle. The tumor was subtotally removed through a right lateral suboccipital craniectomy. The tumor was thought to originate from the brain stem with exophytic growth into the right cerebellopontine angle. Histological examination showed neoplastic ganglional and glial cells with anaplastic features such as mitosis, pleomorphism, and endothelial proliferation. The MIB-1 labeling index of the glial components was 40% to 60%. The diagnosis was anaplastic ganglioglioma (World Health Organization grade IV). She received postoperative radiotherapy but died of respiratory failure with tumor recurrence 11 months after the operation. Gangliogliomas usually have a good prognosis. Histological features of anaplasia and a high MIB-1 labeling index may be predictive of a poor clinical outcome.
A 37-year-old man presented with olfactory neuroblastoma, which apparently recurred as diffuse extension in the subdural space of the cranial vault and spinal column 3 years after initial resection. Head and spinal magnetic resonance imaging with gadolinium demonstrated a subdural lesion. Cytological examination of the cerebrospinal fluid was negative. Histological examination of a biopsy specimen suggested recurrence of the olfactory neuroblastoma. This type of recurrence is very unusual.
A 6-year-old girl, who had received a ventriculoperitoneal (VP) shunt using the Codman-Hakim programmable valve system at age 3 months, presented with intractable seizures. Neuroimaging studies showed migration of the proximal part of the system, including the prechamber, into the cranium through the right frontal burr hole. Electroencephalography showed spike-and-wave complexes in the right hemisphere including the site of the migration. The ictus was resolved following revision surgery. The clinical findings suggested the seizures were due to irritation of the brain parenchyma by the migrated system. Proximal migration of a VP shunt may cause both shunt failure and additional focal symptoms.