[Case with L5 radiculopathy caused by far-out syndrome and lumbar canal stenosis].

Far-out syndrome (FOS) is caused by L5 nerve root entrapment at the L5-S1 extraforaminal area surrounded by the sacral alar and the transverse process. Here, we report a case with right L5 radiculopathy caused by L4-5 lumbar canal stenosis (LCS) and FOS. A 57-year-old man suffered from progressing right sciatica and leg pain in the L5 nerve root distribution. MR images showed canal stenosis and a slight disc herniation at the L4-5 level. He underwent surgical decompression for LCS, but he only obtained partial pain relief. Multiplanner reformatted CT scans showed that the right L5 nerve root was entrapped by the sacral alar and lateral disc bulging at the L5-S1 level. Selective radiculograpy demonstrated L5 nerve root compression in the far-lateral area, and a nerve root block provided temporary pain relief. He received a second operation for decompression of the L5 nerve root in the far-lateral zone by partial removal of the sacral alar and the transverse process. He was relieved completely from pain after the operation. He left our hospital on the 9th postoperative day, and returned to work on the 16th day. Visual analogue scales of pain and numbness were 8.7 and 8.7 respectively at first examination. These scores decreased to 5.5 and 3.7 two months after the first operation for LCS, and to 0 and 0 one month after the second operation for FOS. We recommend that more attention be paid to FOS when patients with L5 radiculopathy are diagnosed.

[Posttraumatic syringomyelia developing soon after spinal cord injury. A case report].

We report a case of posttraumatic syringomyelia (PTS) that developed 10 months after spinal cord injury (SCI), A 46-year-old man was involved in a motorcycle accident, in which he received a severe spinal cord injury due to a burst fracture at the T6 level. The patient underwent posterior fixation without decompression at another hospital, and was transferred to our hospital for rehabilitation. Ten months after the SCI, he complained of back and neck pain caused by bending his head backward. MRI showed syringomyelia shaped like a cone extending from the T6 to the C6 level, enlarged by cerebrospinal fluid (CSF) flow toward the syringomyelia at the T6 level. Pain was relieved by syringosubarachnoid shunt implantation and the syrinx disappeared after the operation. PTS emerging 10 months after spinal cord injury is relatively rare. From the radiological and operative findings, PTS was enlarged by the CSF flow, which was hindered at the T6 level by compression of the vertebral body to the spinal cord. In cases of SCI in patients who undergo posterior fixation with insufficient decompression, close attention to PTS is required in the postoperative follow-up.

Microscopic bilateral decompression through unilateral laminotomy for lumbar canal stenosis in patients undergoing hemodialysis.

OBJECT: Microscopic bilateral decompression through a unilateral laminotomy (MBDUL) is a minimally invasive technique used to treat lumbar canal stenosis (LCS). In the present study, MBDUL was performed to treat LCS in eight patients undergoing hemodialysis. METHODS: Surgical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scale (highest possible score 29). The JOA scale was administered preoperatively, at 1 month and 3 months postoperatively, and at the final follow-up examination. One patient refused to undergo the postoperative assessment after the 1-month examination; the mean follow-up duration of the remaining seven patients was 24 months (range 18-31 months). The mean age at the time of surgery was 62 years (range 48-76 years), and the mean duration of hemodialysis therapy was 21.4 years (range 3-28 years). All patients could walk within 2 days of surgery. The mean angle of the straight leg-raising (SLR) test was 53.8 degrees preoperatively, and this increased to 69.4 degrees postoperatively. Six patients felt enhancement of sciatica or leg pain when performing the SLR test preoperatively, a finding that was absent postoperatively at least until the final follow-up examination. The mean preoperative JOA score was 11.6 (range 4-22), and the score markedly improved to 19.8 (range 15-23) at 1 month and 20.6 (range 16-25) at 3 months. The mean JOA score decreased to 17.1 (range 12-25) at the final follow-up examination, but this decrease was attributed to other physical disorders. CONCLUSIONS: The authors conclude that MBDUL is a safe and effective surgical treatment for patients undergoing hemodialysis who are suffering from LCS.

[Natural history of unruptured cerebral aneurysms of the unoperated and observed cases].

PURPOSE: Natural history of unruptured cerebral aneurysms is still a matter of discussion. In this study, we investigated the prognosis of unruptured cerebral aneurysms of unoperated cases in a prospective design. METHODS: Between September, 1992 and December, 2001, we have encountered a 256 cases of unruptured cerebral aneurysms. Among them, 118 cases were observed and were checked every year for their status. The endpoint was designed as their death and aneurysm rupture. Their rupture rate, mortality due to aneurysm death, and the cause of death other than aneurysm were investigated. Univariate analysis, chi-square test was used as statistics. A p-value less than 0.05 was considered as significant. RESULTS: Annual rupture rate of unoperated unruptured cerebral aneurysms of size below 5 mm, between 5-15 mm, and over 15 mm increased according to the aneurysm size, 0.4%, 3.3% and 9.9% respectively. The sole risk factor for the feasibility of rupture of unruptured aneurysms was their size (p < 0.001). Aneurysm related mortality, however, was high in posterior circulation aneurysms. In patients under 70 years of age, 45% of patients died of cerebral aneurysms, but this rate decreased to 17% for patients over 70 years of age. CONCLUSION: The rupture rate of unruptured cerebral aneurysms over 5 mm in size is not low. Unruptured aneurysms of the posterior circulation may have a much higher risk of rupture, so further investigation is necessary.

Obliteration of bilateral dissecting aneurysms of the vertebral arteries following repeated subarachnoid hemorrhage: a case report.

A 51-year-old man presented with loss of consciousness when he underwent urological examination at another hospital. CT scans showed subarachnoid hemorrhage, and cerebral angiography showed bilateral dissecting aneurysms of the vertebral arteries. Following ventricular drainage, the lesion was managed conservatively with blood pressure control but again ruptured on day 8. Cerebral angiography revealed narrowing of both the dissecting aneurysms. On day 11, the right vertebral artery had been spontaneously obliterated and the right dissecting aneurysm was filled in a retrograde fashion via the left vertebral artery. Proximal occlusion of the right vertebral artery was performed to prevent recanalization. Two months later, cerebral angiography revealed that both vertebral arteries were obliterated and the basilar artery and right posterior inferior cerebellar artery were filled via the right posterior communicating artery. The present case demonstrated that the hemodynamic status of bilateral dissecting aneurysms of the vertebral artery changed variably indicating the necessity of careful angiographic observation.

Investigation of the surgically treated and untreated unruptured cerebral aneurysms of the anterior circulation.

BACKGROUND: The natural history of unruptured cerebral aneurysms and the surgical risks are modified by several factors including size, location, and presence of subarachnoid hemorrhage (SAH). The main confusion arises because the backgrounds of the past reports describing the natural history or the surgical complication of unruptured cerebral aneurysms were different. The present study aimed to adjust the backgrounds and investigate the surgical indication with close monitoring of both surgically treated and untreated unruptured cerebral aneurysms. METHODS: In the past 9 years, 201 patients who had unruptured anterior circulation aneurysms were monitored. The decision of the operation was not randomized. The patients were divided into three subgroups by the size of the aneurysms (small group: below 5 mm, medium group: between 5 and 15 mm, large group: over 15 mm). In both surgically untreated and treated patients, overall mortality and morbidity corresponding to Rankin score II or worse was counted as unruptured aneurysm related event. The ratio of event free was compared between surgically treated and untreated patients using Log-rank test. RESULTS: In untreated patients, SAH was noted in 1 in the small group and 4 in the medium group. The annual rupture rate of the medium group was 12 times higher than that of the small group. In surgically treated patients, overall mortality and morbidity of the surgery was 2.3% in the small group, 3.6% in the medium group, and 20% in the large group. One surgically treated patient had SAH because of regrowth of aneurysm. When ratio of event free was compared, no significant advantage of surgery was noted in the small group and in all of the patients. However, the benefit of surgery was significant in the medium group (Log-rank p = 0.0189). CONCLUSIONS: The present results indicated that prophylactic surgery has a benefit for the medium-size aneurysms (5-15 mm) of the anterior circulation. For large aneurysms, individual investigation is necessary because of the variety of surgical difficulties, and the complex symptoms because of rupture and the mass effect as well as cerebral embolism. In small aneurysms, careful observation may be a reasonable choice unless the aneurysm is at a specially high risk of rupture.

[Carotid endarterectomy in chronic renal failure patients: report of two cases].

Chronic renal failure is one of the risk factors for carotid atherosclerosis. We report two cases of stenosis of the carotid bifurcation treated by carotid endarterectomy. A 66-year-old man with a 17-year history of hemodialysis experienced repeated episodes of right hemiparesis. Cerebral angiography showed severe stenosis of the cervical carotid bifurcation bilaterally. Left and right carotid endarterectomy operations were performed one month apart. The postoperative course was uneventful, and the patient returned home without neurological symptoms. The second case was in a 49-year-old woman with a 15-year history of hemodialysis had vertigo of one month duration. Cerebral angiography revealed occlusion of the left subclavian artery, and the distal left axillary artery was filled by retrograde flow from the left vertebral artery. Stenosis of the right carotid bifurcation was also noted. Right carotid endarterectomy was performed without any complications. Although a high incidence of intraoperative complications and of recurrent stroke after carotid endarterectomy (CEA) has been reported in chronic renal failure patients, the poor prognosis of the natural history of severe carotid stenosis in chronic renal failure should be taken into consideration. The cases reported indicate that carotid endarterectomy is safe and justified for carotid stenosis in chronic renal failure patients.

Allodynia corresponding to the levels of cervical cord injury treated by surgical decompression: a report of 3 cases.

BACKGROUND: The role and timing of surgical decompression for SCI remains controversial, when the surgical outcomes are evaluated only by neurologic recovery. Other than neurologic deficits, severe pain after SCI is a significant problem, deteriorating the patient's activity of daily living. In the present report, allodynia of patients' upper limbs caused by cervical SCI was treated successfully by surgical decompression. CASE DESCRIPTIONS: Three male patients received cervical SCI through minor accidents. They complained of allodynia and motor dysfunction at the spinal level compressed by preexisting lower cervical spondylosis, but they lacked symptoms or neurologic abnormalities below that spinal level. Severe pain was induced by soft touch or exposure to water at room temperature preoperatively. Surgical decompressions of the spinal cord and nerve roots were performed between 20 and 83 days (mean, 48.7 days) after the SCI. Allodynia was reduced in all patients immediately after surgery. Pain induced by soft touch disappeared within 4 days of operations, whereas pain by water exposure diminished within months. Recurrence of allodynia has not been observed in patients at least until the last follow-up, within periods ranging from 15 to 39 months (average, 26 months). The mean preoperative VAS was 6.0, and this improved to 2.2 at 1 month and 0.8 at the final follow-up. CONCLUSION: We propose that patients with SCI with allodynia and motor dysfunction of the upper limbs related only to the compressed spinal levels are potentially treatable by surgical decompression.