Before clinical applications of neural stem/progenitor cells in neural transplantation, many basic problems need investigating; for example, how to induce the differentiation to neurons and how to improve the survival of grafted cells. Therefore, search and analysis for differentiation/survival factors are important areas of neural transplantation research. To for search differentiation/survival factors of dopaminergic (DAergic) neurons, we investigated enhanced trophic factor in the DA-depleted striatum using ELISA and a cDNA microarray. Expression of pleiotrophin (PTN), VEGF and GDNF were enhanced in the DA-depleted striatum. To ascertain the effect of PTN on survival and differentiation of DAergic neurons, cultured DAergic neurons from E15 ventral mesencephalon and ES-derived nestin positive cells were treated with PTN. Cultured DAergic neurons treated with PTN (50ng/ml) at 1 and 3day in vitro increased the number of TH-positive cells at 5day in vitro, although treatment with midkine (50ng/ml), a family protein, did not; indicating that PTN promoted survival specific to DAergic neurons. It was found that PTN treatment to ES-derived nestin positive cells increased the number of TH-positive cells after neural differentiation, showing that PTN promoted differentiation to DAergic neurons from neural stem cells. To ascertain the effect of PTN in neural transplantation, donor cells (E15 ventral mesencephalic tissue) were treated with PTN during cell preparation; cells were transplanted into the striatum of rat hemiparkinson model and methamphetamine-induced rotation testing was carried out until 5 weeks after transplantation. It was found that PTN treatment during cell preparation improved motor functional behavior as compared to controls, and that there were more surviving DAergic neurons in the striatum at 5 weeks after transplantation in ther PTN-treated group. The results showed that PTN treatment of donor cells promotes the recovery of disturbed motor function. Our data indicates that PTN, an enhanced trophic factor in DA-depleted striatum, is useful as a differentiation/survival factor for DAergic neurons in neural transplantation.

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The authors analyzed 16 patients requiring reoperation for lumbar disc herniation among 603 patients who had undergone lumbar disc surgery. The mean age of patients undergoing reoperation was 44 years (range, 23 to 57). Overall occurrence of reoperation was 2.7%. Lesions dissected at reoperation were located the same site as at the initial operation in 7 patients (1.2%), with instability being present in 1 patient (0.2%); at the same level but on the contralateral side in 3 patients (0.5%); and at a different level in 5 patients (0.8%). Microdiscectomy was performed at reoperation in these 15 patients, and the patient with instability underwent spinal fusion at the same level as the lesion. Outcome of microdiscectomy in this series was favorable; spinal fusion is not required routinely in patients undergoing repeat discectomy for recurrent disc herniation. In the absence of objective evidence of spinal instability, recurrent disc herniation may be adequately treated by repeating lumbar microdiscectomy alone.

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The anterior oblique keyhole approach does not require fusion manipulation, and is a useful surgical method that is less invasive for the treatment of discopathy of the cervical spine. This approach can be used even in the treatment of multilevel lesions. However, long-term follow-up study is required to determine the efficacy of this technique. We report 52 cases surveyed more than one year. The mean follow-up period was 36 months. The patients consisted of 30 men and 22 women with an average age of 58.1 years old (33-83 years old). The levels treated with this procedure involved C3/4, C4/5, C5/6, C6/7, and C7/T1. Pathology included: cervical disc hernia, 41 cases; cervical spondylosis, 10 cases; and ossification of the posterior longitudinal ligament, 1 case. The numbers of intervertebral spaces treated with this procedure were 1 (32 cases), 2 (17 cases), or 3 (3 cases). The neurological symptoms included radiculopathy alone in 34 cases, myelopathy alone in 10 cases, and both radiculopathy and myelopathy in 8 cases. Postoperative neurological evaluation was performed in accordance with the Neurosurgical Cervical Spine Scale. Cervical spine computed tomography and magnetic resonance imaging were used for postoperative and follow-up neuroradiological evaluation. The average improvement rate was 86.4% at one month after surgery, and it remained at this level even one year after surgery. We divided the cases into two groups, which were the cases represented with the radiculopathy alone (group 1) and the cases represented with the radiculopathy and myelopathy, myelopathy alone (group 2). Excellent or good outcome was observed in 88.9% of cases in group 1 and in 72.7% of cases in group 2. No patients had postoperative cervical spine instability. The width of anterior decompression was 6 to 12mm with an average of 8.7mm. The average hospitalization period was 10days. There was one case showed spinal cord injury as the postoperative complication. The patients domonstrated no limitation of activity the day after surgery and showed the preservatrion of the neck motion postoperatively because the procedure did not include disc fusion. This method is less invasive and can be performed in elderly patients to improve QOL.

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We present here a case of delayed onset of unilateral locked cervical facet after flexion injury. A man aged sixty-four was intoxicated with alcohol and fell from the stairs of a station striking his parietooccipital region. He complained of pain in the neck, and had difficulty with elevation of his left arm. The first radiographs of his cervical spine suggested flexion injury although these had been regarded as normal in the emergency room. He took bed rest overnight at home and returned to our hospital on the next day, not having recovered from the symptom. Further radiographs showed a right unilateral locked facet at C_4-C_5. After a failed closed reduction, an open reduction through a posterior approach, followed by anterior fusion was successful. Considering the type of cervical spine injury, particular care must be given to interpretation of radiographs. In a case of flexion injury, it is necessary to keep in mind that delayed onset of unilateral locked cervical facet may develop.

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We report a rare case of accessory schwannoma presenting with intratumoral hemorrhage. A 79-year-old man abruptly presented with vertigo, nausea, vomiting, and gait disturbance. Computed tomography revealed mass lesion located on cerebellopontine angle. Craniotomy was performed and demonstrated that the tumor contained a fair amount of hemorrhage and originated from the cranial root of the accessory nerve. The majority of tumors located on cerebellopontine angle are vestibular schwannomas, and other schwannomas are rare. It is often hard to distinguish between them with only symptoms and radiological findings before surgery. Therefore, we should imagine the possibility of rare schwannomas to avoid perioperative complications due to injury of the lower cranial nerves. To our knowledge, this is the first report of a cranial accessory schwannoma presenting with intratumoral hemorrhage. We reviewed the literature of schwannomas presenting with hemorrhage and reported pathological findings in this case.

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We present a case of asymptomatic colonic penetration by an abdominal catheter of a V-P shunt system in a 32-year-old female. Her first V-P shunt catheter was inserted at the age of 1 because of myelodysplasia and hydrocephalus. Her last shunt tubing was inserted at the age of 26. Though the shunt system had been functioning without signs and symptoms of infection or inflammation, an abdominal CT scan detected catheter migration into the descending colon incidentally. The past CT revealed that the catheter had been in the descending colon for about 2years. The shape of the distal catheter was changed in the abdominal X-ray at 46 months before admission, which suggested that the penetration occurred at that time. After removal and replacement of the distal catheter, she suffered from an abscess of the abdominal wall. Reconstruction of the whole shunt system resulted in the complete recovery of shunt functionality. In conclusion, the whole reconstruction may be necessary in patient with penetration that existed for years. We also recommend taking regular abdominal plain films to confirm the position of the distal catheter.

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A 47-year-old woman, who underwent a ventriculo-peritoneal shunt for obstructive hydrocephalus due to a pineal tumor 35years ago, was scheduled to have abdominal surgery for colon cancer. For the peri-operative period, the peritoneal shunt tube was removed and ventricular drainage was performed to control the intracranial pressure using a ventricular shunt tube. After a definitive diagnosis of aqueductal stenosis by drainage test occlusion and MRI, an endoscopic third ventriculostomy was performed. The risk of shunt infection and malfunction due to the abdominal surgery was avoided, and also the damaged, but still functioning, 35-year-old shunt system was removed without shunt revision.

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A 74-year-old Japanese male complained of gait disturbance and lt. hemiparesis. A magnetic resonance imaging (MRI) brain scan revealed multiple mass lesions occupying the rt. parietal lobe. Each lesion shown on MRI during the patient's hospitalization grew and new enhanced lesions occurred in the rt. parietal lobe. The patient underwent a brain biopsy and was diagnosised with toxoplasma encephalitis using an immunostaining technique. He was treated with a combined therapy of Acetylspiramycin and sulfadoxine-pyrimethamine. The mass lesion ceased growing, although his neurological symptoms did not change. The HIV course of infection was indistinct. He was transferred to a HIV specialty hospital afterwards.

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