The effects of N-methyl-D-aspartate (NMDA), glutamate, and glycine on the developmental axons of the neonatal rat spinal cord were investigated. Isolated dorsal column preparations from postnatal day (PN) 0 to 14 Long-Evans hooded rats (n = 119) were used in vitro. Compound action potentials (CAPs) were recorded from the cuneate and gracile fasciculi with a glass micropipette electrode. NMDA (100 μM) significantly increased CAP amplitude in PN 0-6 cords by 21.5 ± 9.2% (mean ± standard error of the mean, p < 0.001, n = 8) and in PN 7-14 cords by 6.7 ± 6.6% (p < 0.001, n = 10). NMDA (10 μM) significantly increased the CAP amplitude by 6.3 ± 2.9% in PN 0-6 cords (p < 0.01, n = 10). The increase of CAP amplitude induced by NMDA (100 μM) in PN 0-6 cords was significantly greater than that in PN 7-14 cords (p < 0.005). Glutamate (100 μM) significantly increased the CAP amplitude by 8.8 ± 8.1% in PN 0-6 cords (p < 0.001, n = 29) and 6.7 ± 7.5% in PN 7-14 cords (p < 0.01, n = 14), and glutamate (10 μM) significantly increased by 6.3 ± 2.9% in PN 0-6 cords (p < 0.01, n = 21). The amplitudes induced by glutamate (100 μM or 10 μM) did not significantly differ between PN 0-6 and PN 7-14 cords. Application of glycine (100 μM) did not significantly alter CAP amplitudes induced by NMDA (100 μM or 10 μM) and glutamate (100 μM or 10 μM). D(−)-2-amino-5-phosphonopentanoic acid (NMDA receptor antagonist) blocked the effects of NMDA and glutamate. These results suggest that NMDA receptor is present on afferent dorsal column axons and may modulate axonal excitability, especially during the 1st week after birth.
Otogenic intracranial infections usually require both neurosurgical and otolaryngological surgery. This prospective, non-randomized study investigated the value of combining both surgical procedures. Thirteen patients with otogenic intracranial abscess were treated by mastoidectomy and abscess removal through the same incision between 1993 and 2002. Another 12 patients underwent abscess removal or mastoidectomy followed by the other procedure within 7 days. The clinical features of the patients were compared. Four patients died in our series. All four patients had Glasgow Coma Scale (GCS) scores of 7 or less. The preoperative GCS score was the main factor in mortality. One patient had recurrence after the combined approach compared to nine patients with recurrence after separate procedures. The surgical procedure was the main factor affecting the recurrence rate. The combined approach and total capsule excision of the abscess may reduce the risk of recurrence of otogenic intracranial abscess.
A 51-year-old female presented with traumatic C6-7 subluxation associated with C-7 fracture due to an automobile accident. She underwent pedicle screw fixation at C-6, C-7, and T-1 for stabilization of the spinal column. A neuronavigation system was used to obtain accurate placement of the pedicle screws. The patient recovered well without further neurological compromise. Postoperative cervical radiography showed reasonable restoration of the vertebral column without delayed kyphotic deformity.
A 17-year-old man presented with sleeping tendency, tenderness of the back of the neck, and left upper monoplegia after a motorcycle accident. Three-dimensional computed tomography on the 2nd hospital day clearly revealed a type I odontoid fracture. His injuries were treated conservatively and he was discharged on the 60th hospital day, with sequelae due to the cervical root avulsion injuries. Type I odontoid fracture is rare and may be caused by coronal distraction of the head and neck area.
A 34-year-old man presented with occlusion of the left vertebral artery (VA) secondary to dissection of the left subclavian artery manifesting as vertigo, nausea, vomiting, and neck pain. On admission, he was alert with left limb and truncal ataxia. Magnetic resonance (MR) imaging and MR angiography showed left cerebellar infarction and occlusion of the left VA. Conventional angiography and three-dimensional computed tomography (3D-CT) angiography showed stenosis with thrombosed pseudo-lumen of the left subclavian artery, and occlusion of the left VA. Presumably the idiopathic dissection of the left subclavian artery had reached the orifice of the left VA, and an embolism from the dissection had caused occlusion of the VA, leading to cerebellar infarction. After one month, he was discharged without severe neurological deficits. Idiopathic dissection of the subclavian artery is very rare. 3D-CT angiography is very useful for the diagnosis of arterial dissection.
A 36-year-old female was treated for a perimedullary arteriovenous fistula (AVF) using intraoperative color Doppler sonography monitoring. Color Doppler sonography before interruption of the fistulous point clearly demonstrated an abnormal hyperechoic lesion. After interruption of the shunting point, the lesion had disappeared. Intraoperative angiography confirmed the disappearance of the perimedullary AVF. Intraoperative color Doppler sonography is a noninvasive, reliable, and cost-effective method for monitoring the effect of interruption on perimedullary AVF.
A 15-year-old boy with achondroplasia developed right hemifacial spasm associated with headache, vomiting, and hearing disturbance. Computed tomography showed hydrocephalus. A ventriculoperitoneal shunt was placed. His hydrocephalus subsequently resolved, the hemifacial spasm and headache disappeared, and his hearing disturbance improved. The episodes of hemifacial spasm were probably related to a small posterior cranial fossa volume, the so-called crowding of the posterior fossa. Increased intracranial pressure due to hydrocephalus apparently contributed to further reduction in the posterior cranial fossa volume and led to the hemifacial spasms. In addition, his hearing disturbance may have been the result of dysfunction of the cochlear nerve due to the increase in intracranial pressure caused by hydrocephalus.
A 33-year-old man presented with a minute tumor incidentally detected by magnetic resonance (MR) imaging screening. 1.5 Tesla MR spectroscopy indicated normal brain tissue whereas 3.0 Tesla MR spectroscopy indicated neoplasm. The tumor was completely resected. The histological diagnosis was fibrillary astrocytoma. Minute glioma, measuring less than 15 mm in diameter on MR imaging, can be completely resected, resulting in a good prognosis. 3.0 Tesla MR spectroscopy can establish the diagnosis in the early stage of glioma.
A 2-month-old female infant had had a parietal mass since birth. Neuroimaging revealed a lipoma under the splenium of the corpus callosum that was connected to the subcutaneous lipoma via a bone defect in the cranium bifidum of the parietal region. At the age of 5 months, partial resection of only the extracranial mass was carried out. The histological diagnosis was lipoma. She grew up normally without neurological disorders during follow up for 12 years after the surgery. In the present case, the intracranial lipoma was associated with the cranium bifidum, and dysraphism was possibly involved in the pathogenesis. Resection of only the extracranial subcutaneous tumor can be performed for cosmetic reasons.
Distal embolism is one of the major causes of morbidity and mortality associated with treating stenotic lesions by endovascular procedures, such as percutaneous angioplasty and stenting. Many devices have been designed and used to prevent this complication. The PercuSurge Guardwire system is recognized as the best system available to prevent distal embolism during stenting. However, this system is sometimes hard to pass through severe stenotic, tortuous lesions because of the poor selectivity and support. The PercuSurge device was safely introduced into two cases of severe stenotic and tortuous lesions with a triple coaxial system and the buddy wire technique, and stenting was performed successfully. These techniques are very helpful for introducing and maintaining this system in the correct position across stenoses with unfavorable configurations.