Anatomical consideration of the anterior and lateral cutaneous nerves in the scalp.

To better understand the anatomic location of scalp nerves involved in various neurosurgical procedures, including awake surgery and neuropathic pain control, a total of 30 anterolateral scalp cutaneous nerves were examined in Korean adult cadavers. The dissection was performed from the distal to the proximal aspects of the nerve. Considering the external bony landmarks, each reference point was defined for all measurements. The supraorbital nerve arose from the supraorbital notch or supraorbital foramen 29 mm lateral to the midline (range, 25-33 mm) and 5 mm below the supraorbital upper margin (range, 4-6 mm). The supratrochlear nerve exited from the orbital rim 16 mm lateral to the midline (range, 12-21 mm) and 7 mm below the supraorbital upper margin (range, 6-9 mm). The zygomaticotemporal nerve pierced the deep temporalis fascia 10 mm posterior to the frontozygomatic suture (range, 7-13 mm) and 22 mm above the upper margin of the zygomatic arch (range, 15-27 mm). In addition, three types of zygomaticotemporal nerve branches were found. Considering the superficial temporal artery, the auriculotemporal nerve was mostly located superficial or posterior to the artery (80%). There were no significant differences between the right and left sides or based on gender (P>0.05). These data can be applied to many neurosurgical diagnostic or therapeutic procedures related to anterolateral scalp cutaneous nerve.

Angiographic features, surgical management and outcomes of proximal middle cerebral artery aneurysms.

OBJECTIVE: Understanding the microanatomy of the proximal middle cerebral artery (M1) and its early branches is very important for aneurysm surgery in this region. However, few articles provide detailed descriptions of such aneurysms. We report the angiographic characteristics of a series of M1 aneurysms and our experience with M1 aneurysm surgery. MATERIALS AND METHODS: Twenty-three patients with 25 (combined) M1 aneurysms presented to our institution from January 2001 to December 2006. We examined the general characteristics and angiographic features of the M1 aneurysms, such as site, size, direction, and their association with early branches. RESULTS: Of the 23 patients with M1 aneurysms, 13 were women and 10 were men. Nineteen of the aneurysms had ruptured prior to presentation. Multiple aneurysms were observed in 10 of the patients. Angiography showed that 14 of the aneurysms were less than 5mm in size, and most of the aneurysmal projections were superior. Eighteen of the aneurysms involved early frontal branches and three involved the lenticulostriate arteries. Postoperative infarction was seen in eight patients. Five of the eight patients showed either no or slight neurological deficits at the follow-up visit. One patient, however, suffered from hemiparesis and aphasia that corresponded to the vascular territory of the early frontal branches and lenticulostriate arteries. Two patients had a total MCA infarction and a posterior fossa infarction, respectively. CONCLUSIONS: This study highlights the need for the critical management of M1 aneurysms, taking into consideration the size and number of aneurysms. By performing careful angiographic investigation of the aneurysm and related early arterial branches of M1, postoperative complications may be minimized.

Multiple intracranial aneurysms with intraventricular hemorrhage in a child with unilateral fibromuscular dysplasia of the renal artery.

A rare case involving multiple intracranial aneurysms with intraventricular hemorrhage (IVH) in a child, accompanied by unilateral fibromuscular dysplasia (FMD) of the renal artery, is reported. A 12-year-old girl presented with secondary hypertension and fourth-ventricle IVH. Cerebral angiography showed multiple aneurysms in the anterior communicating artery, right posterior cerebral artery, and right superior cerebellar artery. Abdominal angiography revealed marked stenosis and dilatation of the left renal artery. Coil embolization of the intracranial aneurysms was successfully performed. Then, a left nephrectomy and autotransplantation were performed. At the time of discharge, she was in an almost normal neurological condition. The association between renal artery FMD and aneurysmal rupture is extremely rare. This case is the first report of multiple intracranial aneurysms with IVH treated successfully with coils in a child concomitant with FMD of the renal artery.

Thrombosed giant aneurysm of the pericallosal artery with inconclusive findings of multiple neuroimaging studies.

A 65-year-old woman presented with a thrombosed giant pericallosal artery aneurysm manifesting as headache and memory loss that developed over a 2-year period. Computed tomography (CT), magnetic resonance (MR) imaging, and conventional and CT angiography could not establish the differential diagnosis. Open craniotomy revealed the mass as thrombosed giant aneurysm from the pericallosal artery. Direct clipping with thrombectomy was performed successfully with an uneventful postoperative course. Thrombosed giant aneurysm of the distal anterior cerebral artery should be considered in the differential diagnosis of an unusual mass in the mid-frontal area, particularly in the presence of inconclusive angiographic and MR imaging findings.

Arterial cerebral air embolism at the site of a spontaneous pontine hemorrhage in a patient receiving erroneous continuous positive pressure ventilation.

We report the case of a 48-year-old male with iatrogenic arterial cerebral air embolism at the site of a spontaneous pontine hemorrhage. The patient inadvertently received continuous positive pressure ventilation without exhalation for a few minutes, resulting in pneumothorax, interstitial emphysema, pneumoperitoneum, and arterial cerebral air embolism at the site of the intracerebral hemorrhage. This is the first report of pneumocephalus without head trauma or previous surgery in which the air embolism occurs at the site of a spontaneous intracerebral hemorrhage. We hypothesize that air preferentially leaked into the brain parenchyma through the weakened perforating pontine artery that caused the intracerebral bleeding.

Rapid disappearance of acute posterior fossa epidural hematoma.

A 34-year-old man presented with an acute epidural hematoma that resolved within 24 hours after a fall. On admission, neurological examination found no abnormalities. Computed tomography (CT) indicated a linear fracture in the occiput. Four hours after the injury, the patient's condition worsened and repeat CT showed a bilateral epidural hematoma in the posterior fossa extending over the bilateral transverse sinuses and severe brain swelling. The patient's family refused surgery. Conservative management with pentothal was performed in the intensive care unit. Follow-up CT 21 hours after the initial injury showed complete resolution of the hematoma and an increase in the CT density of the pericranial soft tissue near the hematoma. The pressure gradient between the subgaleal and epidural space may have been important in the rapid disappearance of this epidural hematoma.

Hyperostotic meningioma with minimal tumor invasion into the skull.

A 56-year-old man presented with a meningioma associated with hyperostotic bone containing little tumor cell infiltration. The patient presented with a growing mass on his right forehead and exophthalmos. Computed tomography (CT) taken 4 years previously revealed only hyperostosis without intracranial lesion. Repeat CT revealed an enhanced intracranial mass with overlying diffuse hyperostosis extending extracranially. The tumor and affected bone were widely removed. Histological examination confirmed rhabdoid meningioma in the intracranial and extracranial lesion. However, most of the hyperostotic bone showed no tumor cell infiltration. The cause of hyperostosis associated with meningioma is unclear, but tumor invasion is the generally accepted cause. In this case, hyperostosis occurred without tumor cell infiltration so another mechanism was probably involved. The extracranial extension occurred despite the disproportionately small tumor without global tumor cell infiltration of the bone or bony erosion.

Influence of interleukin-6 on the development of peritumoral brain edema in meningiomas.

OBJECT: Peritumoral brain edema (PTBE) is associated with perioperative neurological deficits in patients with meningiomas. However, the pathogenesis of meningioma-associated edema remains unclear. In the present study, the authors investigated the expression of interleukin-6 (IL-6) and its relationship with PTBE in resected meningiomas. METHODS: Thirty-six benign meningiomas obtained in 36 patients were studied retrospectively. Edema volume was assessed on MR images, and an edema index (EI) was calculated. Interleukin-6 mRNA and protein expression were examined by real-time reverse transcriptase polymerase chain reaction and immunohistochemical staining. RESULTS: Peritumoral brain edema was found in 16 patients (44%). Neither age, sex, histological subtype, nor tumor location were related to PTBE. The level of IL-6 mRNA was 7.72 times greater in the edema group (EI > 0.2) than in the nonedema group (EI < 0.2; p = 0.011). On immunohistochemical analysis, IL-6 protein was found localized in the cytoplasm of the tumor cells, and was detected in 12 (75%) of 16 cases of edematous meningiomas, but in only 6 (30%) of 20 nonedematous cases. There was a significant correlation between the severity of PTBE and IL-6 expression (p = 0.004). CONCLUSIONS: The authors' results in this study indicate that IL-6 expression may contribute to the development of brain edema associated with meningiomas.

Rapid progression of early delayed radiation effect in pleomorphic xanthoastrocytoma.

Early delayed radiation effects are known to occur within several months after completing radiotherapy for brain tumors. We present marked changes of magnetic resonance imaging (MRI) scan that occurred one month after radiotherapy in a patient with a pleomorphic xanthoastrocytoma, which was eventually diagnosed as an early delayed radiation effect. Such an early development of dramatic MRI change has not been reported in patients treated with radiotherapy for pleomorphic xanthoastrocytomas.

Brain stem hemorrhage following burr hole drainage for chronic subdural hematoma-case report-.

A 76-year-old man presented with brain stem hemorrhage after burr-hole drainage for bilateral chronic subdural hematomas. Neuroimaging demonstrated resolution of the transtentorial herniation but also detected new brain stem hemorrhage, manifesting as gait disturbance. He recovered after conservative treatment. Asymmetrical and rapid decompression, which leads to vascular disruption and/or sudden increase in cerebral blood flow, was probably responsible for the secondary brain stem hemorrhage. Therefore, simultaneous and bilateral decompression with a slow rate of evacuation of massive bilateral chronic subdural hematomas is recommended to prevent serious complications such as secondary intracranial hematoma.

Upregulation of VEGF and FGF2 in normal rat brain after experimental intraoperative radiation therapy.

The expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)2 in the irradiated brain was examined to test how a single high dose radiation, similar to that used for intraoperative radiation therapy given to the normal cerebrum, can affect the vascular endothelium. After a burr hole trephination in the rat skull, the cerebral hemisphere was exposed to a single 10 Gy dose of gamma rays, and the radiation effect was assessed at 1, 2, 4, 6, and 8 weeks after irradiation. Histological changes, such as reactive gliosis, inflammation, vascular proliferation and necrosis, were correlated with the duration after irradiation. Significant VEGF and FGF2 expression in the 2- and 8-week were detected by enzyme-linked immunosorbent assay quantification in the radiation group. Immunohistochemical study for VEGF was done and the number of positive cells gradually increased over time, compared with the sham operation group. In conclusion, the radiation injuries consisted of radiation necrosis associated with the expression of VEGF and FGF2. These findings indicate that VEGF and FGF2 may play a role in the radiation injuries after intraoperative single high-dose irradiation.

Outcome of postoperative intratumoral bleomycin injection for cystic craniopharyngioma.

Total excision is a treatment of choice in preventing the relapse of craniopharyngioma, but for tumors involving an extensive area, it is often associated with an increased risk of complications. We have performed a partial or subtotal tumor removal followed by repeated injection of bleomycin into the remaining tumor through a subcutaneous reservoir as postoperative adjuvant therapy. A retrospective review of clinical, radiological, and surgical data was performed for 10 patients (5 males and 5 females; age, 3-65 yr; follow-up duration, 12-79 months) with cystic craniopharyngiomas. The measurements of lactate dehydrogenase (LDH) level at each aspiration were performed. The shrinkage and/or stabilization of tumor was initially noted in all cases. The recurrence of tumor was seen in 4 cases (40%). The decreased or increased level of LDH was interpreted as tumor shrinkage or recurrence, respectively. The transient toxic reactions were observed in 3 patients (30%). Our study demonstrates that postoperative bleo-mycin injection for cystic craniopharyngioma, although does not appear to eradicate the tumor, decreases and stabilizes the tumor size, when used as an adjuvant therapy in young patients.