The intracranial internal carotid artery (ICA) is a muscular artery and lacks external elastic lamina (EEL). Stenosis of the intracranial ICA is relatively uncommon, but the most common site is the cavernous portion. The characteristics of the arterial wall structures were examined using serial 3-mm sections of 32 intracranial ICAs obtained from 50 cadavers to identify where the EEL disappeared. The portions of the ICA where the intima exhibited thickening were also determined. Both the internal elastic lamina (IEL) and EEL were observed in all 32 specimens of the petrous portion of the ICA. Only the IEL was observed in all 32 specimens of the intradural portion of the ICA. The EEL had disappeared in 31 of the 32 specimens of the horizontal segment of the cavernous portion of the ICA. Intimal thickening of the ICA was observed in 23 of 32 ICA specimens, and frequently appeared in the horizontal segment of the cavernous portion of the ICA. The EEL disappeared in the cavernous portion of the ICA, which is the most common site of stenosis of the intracranial ICA. Change in the elasticity of the arterial wall in the cavernous portion may be an important factor in the process of atherosclerosis in the intracranial ICA.
The efficacy of selecting non-responders to intravenous recombinant tissue plasminogen activator (rt-PA) for mechanical clot disruption (MCD) was investigated based on cerebral angiography in the acute stage following rt-PA therapy. rt-PA therapy using 0.6 mg/kg was performed in eligible patients within 3 hours of onset. Patients who did not show recanalization on cerebral angiography 1 hour after rt-PA initiation immediately underwent MCD. Clinical outcome was evaluated by National Institutes of Health Stroke Scale (NIHSS) score at baseline, 24 hours, and 1 month, and by modified Rankin scale (mRS) score at 3 months. Eighteen patients were initially treated with intravenous rt-PA, with mean time from stroke onset to rt-PA therapy of 120 ± 27 minutes. Eight of these patients underwent MCD. Seven of these eight patients had complete recanalization. Time to recanalization by percutaneous transluminal angioplasty from stroke onset was 258 ± 59 minutes. Final recanalization was achieved in 16 of the 18 patients. Baseline NIHSS score improved significantly at 1 month (median from 22.5 to 4). Twelve of the 18 patients treated according to our protocol were classified as independent (mRS scores 0-2). No patients had symptomatic hemorrhage. MCD for non-responders determined by cerebral angiography at the end of intravenous rt-PA infusion can decrease the time to recanalization and improve recanalization rates, leading to good clinical outcome after acute stroke.
Diffusion-weighted magnetic resonance (MR) imaging findings of 72 patients with subarachnoid hemorrhage (SAH) in the acute stage were investigated to determine the clinical implications of subarachnoid clots detected by diffusion-weighted MR imaging on admission. Correlations between SAH detected by diffusion-weighted MR imaging and clinical factors were analyzed retrospectively. Diffusion-weighted MR imaging detected SAH in 34 of the 72 patients on admission. Thirty-three of 46 patients classified as Fisher group 3 had SAH detected by diffusion-weighted MR imaging. SAH detected by diffusion-weighted MR imaging on admission was significantly associated with both SAH imaging score and chronic hydrocephalus. SAH was detected by diffusion-weighted MR imaging on admission in patients who had dense clots. Detection of SAH by diffusion-weighted MR imaging was correlated with pathological conditions associated with the volume of subarachnoid clot, such as chronic hydrocephalus.
The present study aimed to evaluate the impact of early surgical evacuation of sylvian hematoma caused by ruptured middle cerebral artery (MCA) aneurysm on clinical outcome after subarachnoid hemorrhage. Hospital records and computed tomography scans for 26 patients with MCA aneurysm who underwent surgical clipping between June 2001 and January 2008 were retrospectively reviewed. All patients presented with sylvian hematoma associated with subarachnoid hemorrhage and received surgery at 7.9 ± 3.6 (mean ± standard deviation) hours of ictus. They were divided postoperatively into two groups, achievement (n = 16) and non-achievement (n = 10) of extensive hematoma evacuation, and their clinical course and functional outcomes were compared. The frequencies of delayed ischemic neurological deficit and vasospasm-related cerebral infarction were significantly less (p < 0.05) in the achievement group. Better functional outcomes were obtained in patients with successful evacuation (p < 0.05), as assessed by improvement of hemiparesis on manual muscle testing scale at postoperative 1-month follow up and by the modified Rankin scale at postoperative 3 and 6 months. Clinical outcomes were also better in the achievement group. These results suggest that better clinical course and outcome can be expected in patients who undergo early successful hematoma evacuation with surgical clipping of a ruptured MCA aneurysm.
Three patients developed hemorrhage in the splenium of the corpus callosum 2 weeks after the onset of subarachnoid hemorrhage (SAH) associated with acute hydrocephalus. Computed tomography performed a few days after the onset showed a low density area in the splenium of corpus callosum in all three patients, and preventive measures against symptomatic vasospasm were begun, including vasodilator administration. Computed tomography showed hemorrhage in the splenium of the corpus callosum 17 to 22 days after onset of SAH, manifesting as mental deterioration or headache. Antivasospasm agents were immediately discontinued, and strict blood control measures were instituted. Splenial hematoma is another potential cause of neurological deterioration after surgery for SAH, in addition to vasospasm, hydrocephalus, and rebleeding.
An 81-year-old woman was transferred to our hospital after suffering loss of consciousness. Computed tomography revealed subarachnoid hemorrhage. Angiography revealed middle cerebral artery fenestration and a ruptured aneurysm arising from the inferior limb of the fenestrated artery. Coil embolization of the aneurysm and the proximal portion of the inferior limb was performed, and she showed good recovery after the procedure. Ruptured aneurysms associated with middle cerebral artery fenestration are very rare, but may occasionally have complex structures that complicate lesion treatment, so coil embolization should be considered in some cases.
A 58-year-old man presented with sudden onset of severe headache. Computed tomography demonstrated subarachnoid hemorrhage and right acute subdural hematoma. He had no neurological deficits. Cerebral angiography showed an anterior cranial fossa dural arteriovenous fistula (AVF) supplied by the bilateral ethmoidal arteries. A fistula was suggested on the right side, and the dural AVF drained into the superior sagittal sinus via the bilateral frontal cortical veins. Venous varix was observed at both drainage sites. Bifrontal craniotomy with right-side dural incision was performed and the fistula was interrupted. Postoperative angiography demonstrated a persistent fistula draining into the left cortical vein. Nineteen days later, bifrontal craniotomy with left-side dural incision was performed and the draining vein was completely coagulated with the aid of intraoperative angiography. Postoperatively, there was no detectable residual fistula. He was discharged without neurological deficits 2 weeks after surgery. The present case of anterior cranial fossa dural AVF with bilateral cortical drainers shows that drainer occlusion at two points may be needed for complete obliteration of the drainers because the fistulous connection may not be simple.
A 60-year-old woman with a history of intermittent headaches and frequent seizures for 30 years presented with a massive intracranial hematoma in the left medial temporal lobe with thick subarachnoid hemorrhage. She had been treated with anticonvulsant medication under a diagnosis of left mesial temporal sclerosis based on magnetic resonance imaging findings. Cerebral angiography on admission revealed occlusion of the P2 segment of the left posterior cerebral artery (PCA) and extravasation of contrast medium during the procedure. The patient underwent left temporal lobectomy including the lesioned mesial temporal cortex, and the ruptured P2 segment of the PCA was removed as well. The operative finding of the ruptured aneurysm was pseudoaneurysm. Histological examination of the resected PCA segment demonstrated a pleomorphic xanthoastrocytoma invading the outer wall of the PCA. Presumably the bleeding was caused by the rupture of a pseudoaneurysm secondary to leptomeningeal involvement of this typically benign tumor.
Rosette-forming glioneuronal tumor (RGNT) of the fourth ventricle is a rare tumor included as a novel glioneuronal neoplasm in the 2007 World Health Organization classification of brain tumors. A 15-year-old female patient presented with RGNT of the fourth ventricle manifesting as headache persisting for one month. Magnetic resonance imaging disclosed a nonenhanced solid mass in the fourth ventricle and vermis. The tumor was gross totally resected. Histological examination revealed biphasic neurocytic and glial architecture. The neurocytic component consisted of uniform neurocytes forming neurocytic rosettes and perivascular pseudorosettes. Only 31 cases of RGNT have been reported. RGNT of the fourth ventricle should be considered in the differential diagnosis of infratentorial lesions in young adults. The prognosis is benign, but relatively aggressive behaviors such as tumor growth, recurrence, and acute deterioration due to intratumoral hemorrhaging can occur. Surgical resection requires care to prevent major surgical morbidities associated with lesions invading the cerebellum or brainstem.
A 34-year-old man presented with a case of anaplastic ganglioglioma with malignant features in both neuronal and glial components manifesting as seizure episodes over 11 months. The tumor was subtotally removed, followed by irradiation and chemotherapy. The histological diagnosis was anaplastic ganglioglioma. Atypical cells were morphologically estimated as glial and neuronal cells. Though these cells were weakly positive for synaptophysin and glial fibrillary acidic protein, the neural stem cell marker nestin was extremely expressed in both these cells. The MIB-1 index was 15%. Two months later, the tumor recurred with more pleomorphic appearance and higher cellularity with increased nestin expression level. Mitotic cells and multinucleated cells were found in the neuronal components. Cytological examination found dissemination to the leptomeningeal space. The patient died 6 months after the first surgery. This rare case of anaplastic ganglioglioma with both neuronal and glial components, which were extremely positive for nestin, showed progressive worsening of the clinical course. The expression of nestin may suggest that the origin or malignant transformation in anaplastic gangliogliomas is related to the undifferentiated neural stem cells.
Two patients presented with metastatic pineal tumors. A 69-year-old man had gait disturbance, dementia, and urinary incontinence but no history of previous malignancy. Magnetic resonance imaging of the brain revealed a 23-mm tumor in the pineal region and obstructive hydrocephalus. A 37-year-old man had been treated for thyroid cancer. He presented with vomiting and consciousness disturbance. Brain magnetic resonance imaging revealed a 28-mm pineal tumor associated with intratumoral hemorrhage and accompanying obstructive hydrocephalus. Both patients underwent neuroendoscopic biopsy and third ventriculostomy through the foramen of Monro, resulting in reliable histological diagnoses and subsidence of hydrocephalus.
A 74-year-old woman presented with malignant progression of remnant epidermoid cyst manifesting as sudden onset of right ptosis and double vision. She had right oculomotor nerve paresis. She had a history of surgery for right cerebellopontine angle epidermoid cyst 20 years previously. T1-weighted magnetic resonance (MR) imaging demonstrated a hypointense mass lesion in the right cerebellopontine angle and basal cistern, and an isointense mass in the right paraclinoid region which was strongly enhanced. Diffusion-weighted MR imaging showed hyperintense areas in the right cerebellopontine angle, ambient cistern, and basal cistern, and the paraclinoid mass as hypointense. Surgery was performed using Dolenc's approach. Histological examination revealed that the paraclinoid tumor adjacent to the epidermoid tumor remnant was malignant transformation of epidermoid cyst into squamous cell carcinoma. She was treated with 46 Gy linac radiotherapy. She has been without tumor recurrence for 17 months. Malignant change of epidermoid cyst is extremely rare, but rapid progress of the symptoms suggests malignant transformation. MR imaging with gadolinium is useful for diagnosis.
Ultrasonography performed at 21 weeks of gestation and magnetic resonance imaging at 23 weeks identified a huge tumor in the occipital region. Premature rupture of the membrane occurred at 28 weeks of gestation, so this baby boy was delivered by emergency cesarean section. Anemia and low blood pressure due to hemorrhage from the surface of the tumor required massive blood transfusion and hemostasis. The tumor was conservatively managed. He manifested symptoms of high output heart failure and persistent infection, necrotizing enterocolitis, and septicemia, and died 51 days after birth. Autopsy examination found the black tumor, weighing 885 g, with a clear boundary with the brain parenchyma. Histological examination showed the tumor was contiguous with the thickened dura mater. The tumor consisted of small, spindle-shaped, round, and polygonal cells without characteristic organized pattern, and positive for S-100 protein and neuron-specific enolase, and negative for HMB-45 and glial fibrillary acidic protein. Ultrastructural study revealed melanin granules within the tumor cells. The diagnosis was meningeal melanocytoma. His skin and spinal cord were unremarkable. Complete tumor resection is considered the best treatment option, followed by incomplete resection with postoperative radiotherapy, but we could not deliver aggressive treatment in our patient because of hemorrhage from the tumor surface and his poor general condition.
A 35-year-old female complained of right-sided watery nasal discharge persisting for 2 weeks. Neuroimaging investigations revealed a defect in the lateral side of middle cranial fossa, temporal lobe encephalocele protruding into the lateral extension of the sphenoid sinus, and cerebrospinal fluid (CSF) collection on the right side of the sphenoid sinus. The transcranial approach was performed for resection of the encephalocele and obliteration of the cranial base defect anterolateral to the foramen spinosum with transcranial multilayered closure of the defect using autologous fat, cranial bone graft, and vascularized split temporal muscle. At 1-year follow up, the CSF rhinorrhea had not recurred. Transcranial multilayered closure of the defect is safe and reliable, particularly for large CSF fistula at the far lateral sphenoid sinus.
A 55-year-old man presented with a rare case of both intracranial and intraspinal inflammatory pseudotumors manifesting as progressive motor weakness in his lower extremities. Magnetic resonance imaging revealed a 24-mm diameter tumor-like lesion in the left parietal lobe and an intramedullary 24-mm diameter lesion at the C7 and T1 levels of the spinal cord. These lesions were resected by sequential operations. Histological examination of the resected lesions revealed the presence of excessive collagen fibers infiltrated with polyclonal lymphocytes and plasma cells, and the diagnosis was inflammatory pseudotumor. Immunohistochemical staining with anti-immunoglobulin G4 (IgG4) antibody found no accumulation of IgG4-positive cells. The serum IgG4 level was normal. Thus, this case did not meet the criteria for IgG4-related disease.
A 63-year-old patient presented with cerebral hyperperfusion manifesting as transient aphasia and general tonic convulsions 3 and 4 days after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. Diffusion-weighted magnetic resonance (MR) imaging revealed a focal low-intensity area at the site of anastomosis in the left temporal lobe, with high apparent diffusion coefficient, together with focal intense increase in cerebral blood flow in the same region. This lesion was considered to be pure vasogenic edema caused by cerebral hyperperfusion. Additional treatment with intravenous drip infusion of free radical scavenger and reduction in blood pressure with nicardipine improved the patient's symptoms and brain edema. The brain edema gradually decreased on MR imaging and completely disappeared at 3 months after bypass surgery. Cerebral hyperperfusion is often encountered after recanalization of occlusive arteries, removal of arteriovenous malformations, and carotid endarterectomy, but may also occur after STA-MCA anastomosis.
A 32-year-old, right-handed man presented with chronic headache persisting for the past 5 years. On admission, neurological examination revealed mild papilledema and bitemporal defects of the visual fields. Computed tomography showed a hypodense lesion in the suprasellar region. Magnetic resonance imaging revealed a 2.2 × 2.4 × 2.5-cm heterogeneously hyperintense lesion in the suprasellar region and an infarct region in the right basal ganglia on the T1- and T2-weighted images. The lesion was subtotally removed because part of the capsule was tightly adherent to important surrounding neurovascular structures. Histological analysis confirmed the diagnosis of dermoid cyst. Ruptured intracranial dermoid cyst may manifest as infarction in the basal ganglia caused by localized arterial inflammatory reaction combined with compression of the right internal carotid artery.
A 71-year-old woman with a 25-year history of levodopa (LD)-responsive Parkinson's disease (PD) developed on-off motor fluctuation and severe peak dose dyskinesia. She underwent deep brain stimulation of the subthalamic nucleus (STN-DBS). STN-DBS induced attenuation of her cardinal PD symptoms and marked improvement of dyskinesia without reduction of LD dosage perioperatively. STN-DBS thus markedly attenuated the cardinal symptoms of PD. LD-induced dyskinesia can also be controlled via reduction of LD dosage as an indirect effect of STN-DBS. The present case provides evidence of the direct antidyskinetic effect of STN-DBS, and suggests that LD-induced dyskinesia can be inhibited by stimulation in the area above the STN.
A 72-year-old woman presented with a metastatic brain tumor around the pituitary stalk compressing the chiasm anteriorly and upward. After tumor resection by a left pterional approach failed, a three-dimensional (3D) image of the area of interest was reconstructed using the Vecter Vision2 navigation system and iPlan Cranial planning software version 2.5. Preoperative 3D computed tomography and magnetic resonance imaging data were fused to demonstrate the anatomical relationship between vessels, nerves, and tumor. Clearer demonstration of the optic nerves utilized thin slice axial and sagittal views along the nerves. The 3D reconstructed image demonstrated the spatial relationship of the tumor and surrounding tissue, and suggested the necessity of a right orbitozygomatic approach to create adequate working space for tumor resection. Second surgery according to this preoperative planning was successful. High quality multimodal fusion images in a navigation system has distinct advantages in preoperative assessment of essential structural relationships allowing adequate exposure of certain lesions and surrounding structures in individual patients by defining specific surgical approaches.
Bonnet bypass is recommended for the rare patients in whom no alternative revascularization procedure is available. Fixation and protection of the interposition graft are important for stable anastomosis, and to avoid mechanical injury after operation. Here, we describe a new technique for fixation and protection of the interposition graft in bonnet bypass. The interposition graft is passed through a bone groove created in the skull, and covered with microplates, temporal fascia, and muscle. The method prevents the interposition graft from slipping out during the anastomosis, and can also protect the graft from mechanical injury after the operation.