Anterior vertebral artery decompression with an ultrasonic bone curette to treat bow hunter's syndrome.

We report a patient with bow hunter's syndrome who was treated by anterior decompression of the vertebral artery (VA) using an ultrasonic bone curette (SONOPET). This 60-year-old man reported almost losing consciousness upon head rotation. Although the right VA appeared normal at the natural head position, upon left head rotation it became completely occluded at the transverse foramen of C2. We performed anterior decompression of the right VA at the axis using a high-speed drill and SONOPET. For anterior decompression of the VA in a deep and narrow operative field, we recommend use of SONOPET, which permits safe, easy bone dissection.

Factors in neurological deterioration and role of surgical treatment in lumbosacral spinal lipoma.

The purpose of this study was to determine factors that might be involved in neurological deterioration and the role of surgical treatment in patients with lumbosacral spinal lipoma. Pre- and postoperative courses of 34 patients were retrospectively analyzed. The age at surgery ranged from 1 month to 47 years. The records of preoperative neurological status indicated that older patients had more severe deficits, while all 8 asymptomatic patients were under 5 years of age. Motor deficits were noted in 9 patients, in 7 of whom the lipoma extended cranially beyond the L5 level. Transitional-type lipomas were accompanied by more severe deficits (asymptomatic 1, symptomatic 17) than other types (asymptomatic 7, symptomatic 9). Postoperative follow-up periods ranged from 5 months to 13 years. During these periods, 7 of the 8 asymptomatic patients remained neurologically intact. Nine of the 26 symptomatic patients improved. Age, extension of the lipoma in the spinal canal and type of lipoma will influence the preoperative neurological status of the patients. Early untethering surgery is recommended in patients with large lipomas extending beyond the L5 level.

Small-field fractionated radiotherapy with or without stereotactic boost for vestibular schwannoma.

PURPOSE: To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas. METHODS AND MATERIALS: Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SB. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).dash;p > RESULTS: Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively. CONCLUSIONS: Small-field fractionated radiotherapy with or without SB provides excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results.

Comparison between observation policy and fractionated stereotactic radiotherapy (SRT) as an initial management for vestibular schwannoma.

PURPOSE: To compare the use of an observation policy with that of stereotactic radiotherapy (SRT) for treatment of vestibular schwannoma. METHODS AND MATERIALS: The study group consisted of 27 patients who underwent observation as an initial treatment (observation group) and 50 who received SRT (SRT group). The mean follow-up period was 35 months and 31 months, respectively. Stereotactic radiotherapy consisted of small-field fractionated radiotherapy (36-44 Gy in 20-22 fractions over 6 weeks) with or without a subsequent 4-Gy single irradiation boost. RESULTS: Actuarial tumor control rate of the SRT group was significantly better than that of the observation group (p < 0.0001). The mean growth was 3.87 mm/year in the observation group and -0.75 mm/year in the SRT group (p < 0.0001). Eleven patients (41 %) in the observation group and 1 (2 %) in the SRT group received salvage therapy (p < 0.001). There was no difference in the actuarial Gardner and Robertson's class preservation curves for 5 years after the initial presentation. CONCLUSION: Stereotactic radiotherapy using a fractionated schedule provides a better tumor control rate and a similar rate of deterioration for hearing levels compared to an observation policy. Initial SRT may be a reasonable alternative to a wait-and-see policy.

Photoluminescence imaging of phosphor particles using near-field optical microscope with UV light excitation.

We have developed fibre probes suitable for 325 nm UV light excitation and a photoluminescence near-field scanning optical microscope (NSOM) and demonstrated the photoluminescence imaging of phosphor BaMgAl10O17:Eu2+ (BAM) particles. The probe was fabricated by a two-step-etching method that we developed. The probe had a large taper angle at the top of the probe and a small taper angle at the root. The NSOM image was different from the topographical structure but roughly reflected the corresponding features of the particles. The inhomogeneity of the photoluminescence intensity between BAM particles was observed in the NSOM image. The photoluminescence intensity with various bandpass filters showed differences between the individual particles, which means that they have different spectra.

A surgical technique for a vertebral column autograft using the intervertebral disc for cervical disc disease.

We describe a surgical technique for a vertebral column autograft using the intervertebral disc for cervical disc disease for patients whose major problem is not spinal instability. Of a total of 41 patients with cervical disc disease suffering from cervical spondylotic radiculomyelopathy, 33 patients were operated on at one level and 8 patients were operated on at two levels. Postoperative X-ray film showed some movement at the "operated" disc level in all patients (average postoperative follow-up period was 43 months, range two years to 5 years). A significant decrease in motion in the extension position was observed postoperatively (p < 0.0001), but no significant difference was observed between the preoperative motion and the postoperative motion in the flexion position. Anterior angulation was found in two (5%) of the 41 patients. This surgical procedure has two major advantages: 1) no complications related to the iliac donor site, allowing early patient mobilization; 2) the extensive posterior spur can be removed safely and easily under a wide operative field. We believe that this surgical procedure is suitable for preserving the mobility of the spine and may avoid stress concentration at adjacent levels of the "operated" disc. However, in patients whose major problem is spinal instability, anterior cervical fusion should be performed.

Audiological assessment before and after fractionated stereotactic irradiation for vestibular schwannoma.

PURPOSE: To find the audiological outcome after LINAC-based fractionated stereotactic irradiation (STI). MATERIALS AND METHODS: Twenty-four patients with vestibular schwannoma treated by fractionated STI between 1991 and 1997 had measurable hearing before STI and were followed audiologically for more than 6 months. The pure tone average (PTA) was measured by averaging the air-conduction threshold for five main frequencies (250-4000 Hz) before and periodically after STI in the 24 patients. Several possible prognostic factors for hearing preservation (defined as a PTA change at the last follow-up of less than 10 dB) were investigated. The median follow-up time was 22 months, ranging from 5 to 69 months. The irradiation schedule was 36 Gy in 20 fractions in 5 weeks to 44 Gy in 22 fractions in 6 weeks followed by 4 Gy/1 fraction boost. RESULTS: The pure tone average before STI was distributed from 7 to 73 dB. Fifty percent of patients showed a change in PTA of less than 10 dB, 79.2% of patients showed a change in PTA of less than 20 dB and 20.8% of patients showed a change in PTA of more than 21 dB at the last follow-up. Only one patient (4%) became deaf. Cases with a sudden loss of hearing were more likely to experience hearing preservation than those with gradual loss of hearing (P<0.05). The mean age was younger in patients whose hearing was preserved (P<0.05). Poor pretreatment PTA appeared to linearly correspond to the changes in PTA (regression coefficient 0.78). The size of the tumor was not related to the change in PTA. No relationship was observed between the maximum or peripheral dose and the PTA change. The real benefit of stereotactic boost after small-field fractionated irradiation was not certain. CONCLUSION: Fractionated STI produced a hearing preservation rate compatible with meticulously collimated multi-spots single fraction irradiation. Further follow-up is required to confirm the long-term benefits of fractionation.

Intraoperative electrocorticography and successful focus resection in a case of Sturge-Weber syndrome.

This paper reports a surgically treated case of Sturge-Weber syndrome (SWS) in which the epileptic foci and haemangiomatosis were successfully resected under monitoring of intraoperative electrocorticography. The patient was a 19-month-old female infant who was referred to our hospital because of frequent hemi-tonic-clonic convulsions that were resistant to anticonvulsant therapy. Serial MRI showed progressive atrophy in the left fronto-parieto-temporal lobe, and gyral enhancement by gadolinium corresponded to venous haemangiomatosis of SWS. Three-dimensional reconstruction of the MR images was performed using the Viewing Wand System. Conventional EEG taken before the operation showed slow activity in the left frontal lobe. Intraoperative ECoG revealed spike focus at the posterior temporal cortex to the margin of the haemangiomatosis. Lesionectomy with lobar corticectomy of the total frontal and parietal lobe and part of the temporal lobe was performed. The epileptogenic focus detected by ECoG in the posterior temporal lobe was also resected. In post-excisional ECoG, epileptogenic activities had disappeared. The patient had hemiparesis and hemihypesthesia just after the surgery, but gradually recovered from the paresis and almost has normal motor function except for right-hand clumsiness up to 1 year after Surgery. The present study demonstrated that lobar corticectomy of the haemangiomatosis-affected cortex with resection of the neighbouring epileptogenic focus is a good surgical alternative even if a haemangiomatosis of the SWS affected multilobar corti of the hemisphere.

Role of basic fibroblast growth factor in the pathogenesis of moyamoya disease.

The pathogenesis of moyamoya disease is still under investigation. In this study, the authors focus on the role of cytokines in the pathogenesis of moyamoya disease by using immunohistochemical analyses. The authors examined two specimens in the circle of Willis obtained at autopsy from two patients with moyamoya disease and two additional specimens obtained from control cadavers with atherosclerotic stenosis of the intracranial carotid arteries. Immunohistochemical examinations of the sections of the major intracranial arteries were performed using antismooth muscle cells (SMCs), monocytes, growth factor, cell nuclear antigen, and fragmented DNA antibodies. Basic fibroblast growth factor (bFGF) staining was present only in the endothelial cells of the moyamoya disease specimens and was not seen in control samples. In addition, the endothelial cells and SMCs in the media were positive for terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick-end labeling of fragmented DNA method but not in the SMCs in the intima in moyamoya disease specimens, which indicates that an apoptotic process is active in only SMCs in the media but not in the intima. In conclusion, it is suggseted that the presence of bFGF in the media specifically seen in moyamoya disease suppresses the apoptotic process of SMCs in the intima.

Surgical treatment supposed natural history of the tethered cord with occult spinal dysraphism.

We retrospectively evaluated the pre- and postoperative course of 34 tethered cord patients with occult spinal dysraphism in an attempt to infer the natural history of this disorder and to determine the effectiveness of the surgical treatment. There were 32 cases with lumbosacral lipoma and 2 with tight filum terminale. The age at surgery ranged from 1 month to 47 years old. Eight patients, aged 1 month to 4 years old, were asymptomatic; 26 had neurogenic bladder (26 cases) or motor problems affecting the legs (8 cases). None of the patients older than 5 years of age were asymptomatic. Untethering of the spinal cord was performed in all cases. The postoperative follow-up period ranged from 5 months to 11 years. During these periods, 7 (88%) of the 8 asymptomatic patients remained neurologically intact, 6 (23%) of the 26 symptomatic patients showed improved symptoms, and 15 patients (58%) remained unchanged. These results indicate that the neurological symptoms will appear progressively in the tethered cord patients, and that prophylactic surgery should be considered as early as possible.

Surgical treatment of syringomyelia associated with spinal dysraphism.

Clinical and radiological features of syringomyelia in 15 patients with spinal dysraphism are reported. There were 8 patients with occult spinal dysraphism (lumbosacral lipoma) and 7 with spina bifida aperta (meningomyelocele). Syringomyelia with spinal dysraphism can be radiologically divided into two types according to the dysraphic state. The syrinx in the patients with occult spinal dysraphism occurred immediately rostral to the lipoma and was localized to the lower thoracic to lumbar levels, while in the meningomyelocele patients the syrinx extended from the cervical to the thoracic level. Large syrinx formation was recognized in 1 of the 7 occult spinal dysraphism cases and 3 of the 8 meningomyelocele cases. For syringomyelia with occult spinal dysraphism, 4 patients underwent syringo-subarachnoid shunting (S-S shunt, 2 cases) or syringostomy (2 cases) during an untethering operation. In the case of meningomyelocele, S-S shunts were placed in 2 patients. Collapse of the syrinx was achieved in all 6 patients who underwent S-S shunting or syringostomy. Decreased size of the syrinx was also noted in 3 occult spinal dysraphism patients who underwent untethering operations alone. In conclusion, a large syrinx in the case of spinal dysraphism should be surgically treated. S-S shunting is effective in both types of syringomyelia. Foramen magnum decompression may be an alternative method of surgical treatment for syringomyelia in patients with meningomyelocele.

Anterior decompression and fusion using bone grafts obtained from cervical vertebral bodies for ossification of the posterior longitudinal ligament of the cervical spine: technical note.

OBJECTIVE: To describe a surgical technique of anterior decompression and fusion using bone grafts obtained from cervical vertebral bodies with ossification of the posterior longitudinal ligament of the cervical spine. This technique seeks to avoid complications associated with an anterior approach of decompression and bone fusion, which widely uses autogenous bone from the iliac crest. METHODS: Forty patients with cervical myelopathy were studied. The ossified ligament was localized to one, two, three, four, five, six, and seven vertebral bodies in 10, 18, 5, 4, 1, 1, and 1 patients, respectively. The ossified area of all posterior longitudinal ligament was completely removed using microsurgical techniques, and 11 patients were operated on at one level, 21 at two levels, and 8 at three levels. RESULTS: The symptoms of all patients improved after the operation. Postoperative x-ray films showed solid bone fusion in all patients at a mean follow-up time of 3 years (range, 1-5.25 yr). Anterior angulation was found in one of eight patients (13%) who underwent three-level fusion. CONCLUSION: Two major advantages were as follows: 1) no complications related to the iliac donor site occurred, and 2) early mobilization of patients was possible with a soft cervical collar. Anterior decompression and fusion should be used for cases with ossification of up to three consecutive vertebrae needing either one- or two-level fusions.

Stereotactic irradiation without whole-brain irradiation for single brain metastasis.

PURPOSE: The effectiveness of stereotactic irradiation (STI) alone without whole-brain irradiation (WBI) for a single metastatic brain tumor was analyzed retrospectively. METHODS AND MATERIALS: Forty-four patients with this condition were treated using radiosurgery (RS) alone or fractionated stereotactic radiotherapy (FSR) without WBI. RESULTS: The initial response rate was 92% and the overall local control rate was 84% (37 of 44 patients). A total of 39% (18 of 44) of patients experienced intracranial relapse outside the initial target area. Forty-eight percent (21 of 44) of patients required salvage treatment for intracranial relapse. All 7 patients who received WBI as salvage treatment required no further salvage treatment, but 5 of the 14 patients who received salvage STI without WBI required three to four treatments for brain metastasis. Late radiation damage was not seen with initial treatment but was observed with retreatment. The overall median survival time was 261 days, with a standard error of 64 days. Actuarial survival at 12 and 24 months was 34% and 9%, respectively. The actuarial survival rate was significantly affected by the existence of active extracranial disease (p = 0.041). CONCLUSION: The high response rate and short treatment period of STI alone are advantageous in the treatment of single brain metastasis in patients with active extracranial disease with WBI reserved for relapse. Because of the low complication rate, STI alone may be also useful in patients with good prognosis, without extracranial disease.

[Stereotactic irradiation for brain metastases using linear accelerator].

A stereotactic irradiation (STI) system using a linear accelerator was developed and its effectiveness for brain metastasis was investigated. The system consisted of a conventional linear accelerator, invasive fixation head frame (RADFRAME, Mizuho Ika Kogyo), and a tungsten collimator. The RADFRAME was developed to be used with any linear accelerators and with any dose planning systems. The accuracy of the irradiation was assured to be within +/-1.5mm. Fifty-one patients with metastatic brain tumors were treated using the system. The overall median survival time was 10 months. No difference in survival was observed between patients with a single lesion and patients with two or three lesions. Complete, partial, and minimal responses were obtained in 16 (39%), 18 (41%), and 7 (16%) lesions. These were comparable to the reported results of gamma knife treatment. A maximum dose of 25 Gy was suggested to be more effective than lower doses. Local control rate was higher in tumors with a diameter of less than 2.0cm (87.5%) than in larger tumors (60%). No difference in tumor response was observed among various histopathologic types. In a patient with a 25mm cerebellar metastasis from an adenocarcinoma of the lung, autopsy at 5 months after STI showed fibrinoid degeneration and hyaline deposition without residual tumor at the Gd-enhanced region on MRI. The efficacy of linac stereotactic irradiation was equal to that of gamma knife radiotherapy for metastatic brain tumors.

[New surgical technique of anterior decompression for cervical disc disease: vertebral column autograft with the intervertebral disc after anterior cervical decompression].

The authors describe the surgical technique of vertebral column autograft with the intervertebral disc after anterior decompression for cervical disc disease. This series consisted of 41 patients with cervical disc disease suffering from cervical spondylotic radiculomyelopathy. There were 27 men and 14 women, ranging in age from 27 to 72 years (mean age 49 years). 33 patients were operated on at one level and 8 patients at two levels. The average postoperative follow-up period was one year 10 months and ranged from 6 months to 3 years 3 months. The patients were generally allowed out of bed wearing a soft collar within 1 day postoperatively. The collar was used for 2 months after surgery. The postoperative course of all patients was uneventful and neurological symptoms improved. Postoperative X-ray films showed some movement in the operated disc level in all patients. The authors think that this surgical procedure may be suitable for preserving mobility of the spine.

[A case of metastatic choriocarcinoma associated with cerebral thrombosis and aneurysmal formation].

A rare case of metastatic choriocarcinoma with cerebral thrombosis and subsequent neoplastic aneurysm formation and rupture is reported. Three months after normal pregnancy and normal delivery, a 16-year-old woman was admitted with the chief complaints of speech disturbance and paresthesia of her right upper extremity on June 4, 1992. Both CT and MRI demonstrated cerebral infarction in the left insula. A cerebral angiogram revealed that the left middle cerebral artery (about 2 mm in diameter) was occluded in the distal M2 segment. On the 34th day, a follow up angiogram demonstrated a fusiform aneurysm at the same point of the arterial occlusion that had been already recanalized. On the 37th day, she suddenly had severe headaches and consciousness disturbance. CT showed subarachnoid hemorrhage. Resection of the aneurysm and left STA-MCA anastomosis were performed. Histological examination revealed that the aneurysmal walls were invaded by choriocarcinoma. On the 60th day, she was transferred to the department of obstetrics and gynecology for chemotherapy. On the 65th day and the 71st day, the patient suffered from intracerebral hemorrhage in the left basal ganglia, which originated from a different point of aneurysmectomy. She died because of the rapid growth of liver metastases 7 months after initial admission. Because chest CT and roentgenogram detected no lesion in the lungs, neoplastic embolus was unlikely as a cause of occlusion of the cerebral artery of about 2 mm in diameter. It would be more reasonable to believe that choriocarcinoma metastasized to the cerebral arterial walls initially and formed a thrombus which occluded the artery. As the neoplastic invasion weakened the arterial wall, a fusiform aneurysm was formed when the vessel was recanalized. There has been no case reported in the literature of neoplastic aneurysms of choriocarcinoma in which the course from aneurysmal formation to rupture was followed angiographically.

[Two cases of ossified spinal meningioma].

It is generally known that meningioma has histological pleomorphism and ossification is one of them. In the cases of spinal meningioma, osteoblastic type is rare. We encountered two different types of ossified spinal meningioma. Two cases of ossified spinal meningioma are reported in this paper. One case is that of a 45-year-old male who had a sudden transient tetraparesis with a tumor located in the upper cervical spinal column. The tetraparesis was caused by the patient's head having been hit. Another case is a 74-year-old female, who had progressive paraparesis and hypesthesia in her lower extremities, with a tumor located in the 9th thoracic spinal column. The MRI findings in these cases suggested that an ossified area was included in the tumor. We performed surgical therapy in both cases, and an operative finding was that these tumors had a very hard component. Histopathological diagnosis in both cases was meningioma. The former included isolated matured bone tissue with fat marrow mixed with the tumor tissue, and the latter included scattered matured lamellar bone tissue. These tumors are considered to be osteoblastic in type.

Intra-operative monitoring by facial electromyographic responses during microvascular decompressive surgery for hemifacial spasm.

The facial electromyographic response was monitored intraoperatively in 40 patients with hemifacial spasm who were operated on by microvascular decompression of the facial nerve. All 40 patients showed an abnormal facial electromyographic response (lateral spread response) with a latency of about 10 msec after stimulation. The abnormal response resolved before decompression in 22, resolved immediately with decompression in 16, and failed to resolve in two. Of the 38 patients in whom the abnormal response disappeared during surgery, 36 were postoperatively free from hemifacial spasm and two had mild hemifacial spasm. The two patients in whom the lateral spread response did not disappear during surgery showed persistent hemifacial spasm. In conclusion. Disappearance of the lateral spread response during surgery correlated with the absence of hemifacial spasm in the early postoperative period. The prognosis of hemifacial spasm was good in cases in whom the lateral spread response disappeared. Therefore, the authors think that intra-operative facial electromyography is very useful in assessing the efficacy of microvascular decompression and in predicting the prognosis of hemifacial spasm.