Olfactory sphere cells are a cell source for γ-aminobutyric acid-producing neurons.

Olfactory sphere cells (OSCs) are stem cells generated by culturing olfactory mucosa. Adult rat OSCs express oligodendrocyte progenitor cell (OPC) markers and differentiate into mature oligodendrocytes. Although OSCs also express nestin, a marker of neural stem cells (NSCs), it remains unclear whether adult rat OSCs are multipotent and capable of giving rise to neurons as well as oligodendrocytes. Valproic acid (VPA) is a histone deacetylase inhibitor that has the contradictory capacity to induce both differentiation of NSCs and dedifferentiation of OPCs. This study investigates a potential role for VPA in inducing either differentiation or dedifferentiation of adult rat OSCs. Treatment of OSCs with VPA induced hyperacetylation of histones and decreased cell proliferation in the absence of changes in the number of nestin-positive cells. Furthermore, VPA promoted the genesis of γ-aminobutyric acid (GABA)-producing neurons identified by expression of Tuj1/GAD67/GABA while repressing oligodendrocyte production. These findings suggest that OSCs treated with VPA did not exhibit stem cell properties indicative of dedifferentiation but rather switched to a neuronal identity during their terminal differentiation. OSCs were then transplanted into the hippocampus of rats with kainic acid-induced temporal lobe epilepsy and were systemically given VPA. Although grafted OSCs expressed Tuj1 and GAD67, these cells did not sufficiently inhibit epileptic activity. These results suggest that OSCs are a transplantable cell source for GABA-producing neurons that can be modulated by VPA. However, further investigation is required to develop them for clinical applications.

Retro-odontoid synovial cyst resected via an anterolateral approach without fusion.

PURPOSE: Retro-odontoid synovial cysts are rare and attributable to degenerative changes in the atlantoaxial joints. An anterolateral approach facilitates access to lesions located anterior to the craniocervical junction without harming the atlantoaxial joints, and can also treat small lesions in the ventral mid-portion of the craniocervical junction without compression of spinal cord. METHODS: We present herein the case of a 70-year-old man with a retro-odontoid synovial cyst. A ventral midsection mass was present at the level of the atlantoaxial joint. The compressed anterior medulla led to neurological deficits. Slight atlantoaxial instability was radiologically present. An intradural cyst resection without fusion was performed via the anterolateral approach. The diagnosis of a synovial cyst was histologically confirmed. RESULTS: The patient was followed up for 3 years and exhibited improvements in the neurological deficits. There were no recurrence and postoperative deterioration of atlantoaxial instability. CONCLUSIONS: The anterolateral approach for the retro-odontoid synovial cyst had little effect on C1-2 instability and yielded neurological improvements.

Primary olfactory mucosal cells promote axonal outgrowth in a three-dimensional assay.

Among the possible sources of autologous cells and tissues for use in spinal cord injury grafts, one promising source is the olfactory mucosa containing olfactory ensheathing cells and neural progenitor cells. Olfactory mucosa transplantation for spinal cord injury has been effective in animal models and in pilot clinical trials. However, the contributions of olfactory ensheathing cells and neurons in olfactory mucosa are unclear. For the present study, we prepared primary olfactory mucosal cells and used a cortex-Matrigel coculture assay system to examine the axonal outgrowth of olfactory mucosa. Axonal outgrowth from cortical slices was significantly enhanced in olfactory mucosal cells compared with noncell controls and respiratory mucosal cells, which have few olfactory ensheathing cells and neurons. Axonal outgrowth was severely reduced after treatment with an antineurotrophin cocktail. A conditioned medium in the olfactory mucosa-derived cell group contained neurotrophin-3. Some olfactory ensheathing cells and almost all neurons were immunopositive for neurotrophin-3. Axons originating from cortical slices targeted mainly the astrocyte-like olfactory ensheathing cells. Our findings demonstrate that the axonal outgrowth effect of olfactory mucosa is supported by both olfactory ensheathing cells and neurons in olfactory mucosa.

Cortical bone trajectory fixation cause low compression force in anterior vertebral column.

Background: The cortical bone trajectory (CBT) screws follow a caudocephalad and lateral path from the pedicle to the vertebral body. The bone fusion rate of CBT fixation is equal to or lower than conventional pedicle screw fixation. It remains unclear whether or not CVT screws exert equally compressive forces across the vertebral column. In this study, we intraoperatively examined the insertional torque of CBT screws, and investigated the compression loading and pressure distribution in conventional and CBT fixation using pig bones. Methods: The insertional torque was measured for a total of 115 CBT screws. Detailed positions of these screws were retrospectively confirmed using CT scans. Screw loosening and interbody fusion were examined 1 year after surgery. In the experiment using pig bones, we inserted screws by conventional trajectory (n = 3) and CBT (n = 4). Results: Multiple regression analysis showed that the total screw length, the distance from the screw to the medial border of the pedicle and the distance from the superior endplate of the vertebrae were significant independent factors affecting the insertional torque. There was no significant association between the insertional torque and the radiographic bone fusion rate 12 months after surgery. The average pressure and the compression loading in the anterior column were significantly lower in CBT group. Conclusion: These results suggested that the long CBT screws as close to the endplate had high insertional torque, but the anterior column in CBT fixation showed low compression force leading to the insufficient holding intervertebral cage. CBT screws may cause the micromotion of cages, which lowers the bone fusion rate.

Bow hunter's stroke due to instability at the uncovertebral C3/4 joint.

Bow hunter's stroke is typically due to mechanical compression or stretching of the dominant vertebral artery (VA) during contralateral head rotation against the bony elements of the atlas and axis. We report a case of vertebrobasilar insufficiency due to bilateral vertebral artery occlusion at the left C3-4 and the right C1-2 junction on rightward head rotation. A 64-year-old man experienced ischemic symptoms during 90° head rotation to the right with complete resolution of symptoms after returning his head to the neutral position. Dynamic cervical angiography with rightward head rotation showed severe compression of the right VA at the transverse foramen of C3-4 and mechanical stenosis of the left VA at the C1-2 level. During head rotation, the flow of the right VA was decreased more than the left side. Cervical 3-D computed tomography (CT) on rightward head rotation demonstrated displacement of the uncovertebral C3-4 joint, with excessive rotation of the C3 vertebral body. Based on these findings, instability at C3-4 was suspected to be the main cause of the vertebrobasilar insufficiency. Anterior discectomy and fusion at the C3/4 level were performed. Postoperatively, the patient experienced complete resolution of symptoms, and dynamic cervical angiography showed disappearance of the compression of the right VA. To our knowledge, this is the first reported case of bow hunter's stroke diagnosed by dynamic cerebral angiography and cervical 3-D CT without angiography, and treated by anterior decompression and fusion without decompression of the VA.

An increase in the posterior subarachnoid space accelerates the timing of syrinx resolution after foramen magnum decompression of type I Chiari malformation.

Syrinx resolution has been associated with an increase in the size of the posterior subarachnoid space (pSAS) after foramen magnum decompression (FMD) for type I Chiari malformation (CM1). The present study investigated the influence of pSAS increase on syrinx resolution and symptom improvement after FMD. 32 patients with CM1 with syrinx were analyzed retrospectively. FMD was performed for the 24 patients with CM1 with syrinx. pSAS areas were measured on sagittal magnetic resonance images. Neurological symptoms were grouped into three clinical categories and scored. The rates of symptom improvement in the CM1 patients with syrinx after FMD was 19.7% ± 12.9%. The mean times to the improvement of neurological symptoms in CM1 patients with syrinx after FMD was 23.4 ± 50.2 months. There were no significant differences between the patients with and without improvement of syrinx after FMD with regard to the age, length of tonsillar herniation, BMI, and preoperative pSAS areas. The rate of increase in the pSAS areas was significantly higher in the group with syrinx improvement within 1 year (p < 0.0001). All patients with a > 50% rate of increase in the pSAS area showed syrinx improvement. Our results suggested that the increasing postoperative pSAS area accelerated the timing of syrinx resolution.

Olfactory mucosal transplantation after spinal cord injury improves voiding efficiency by suppressing detrusor-sphincter dyssynergia in rats.

PURPOSE: Several recent studies showed that olfactory mucosal transplantation after spinal cord injury promotes extensive regeneration of the injured spinal cord. We examined the efficacy of olfactory mucosal transplantation for bladder dysfunction after spinal cord injury in rats. MATERIALS AND METHODS: In adult female rats the Th9-10 spinal cord was completely transected, followed by olfactory mucosal transplantation or gelatin sponge filling as the control. Each group was examined by cystometrogram and external urethral sphincter electromyogram. Calcitonin gene-related peptide and growth associated protein 43 double positive expression in the L6/S1 dorsal horn was evaluated by immunohistochemistry. Transplant sites were examined by immunohistochemistry with antibodies against neurofilament M and neuronal class III beta-tubulin. RESULTS: On cystometrogram voiding efficiency was significantly higher in the transplantation group than in controls. On external urethral sphincter electromyogram with simultaneous cystometrogram the transplantation group showed a larger ratio of interburst silent periods to burst activity duration and a greater number of high frequency oscillations. In the transplantation group calcitonin gene-related peptide and growth associated protein 43 double positive expression in the L6/S1 dorsal horn was less dense than in controls. The transplantation group showed strong neurofilament M and neuronal class III beta-tubulin expression at the transplant site. CONCLUSIONS: Olfactory mucosal transplantation after spinal cord injury weakened external urethral sphincter excessive bursting and increased the urethral opening to improve voiding efficiency. Olfactory mucosal transplantation may modify emergence of the spinal micturition reflex after spinal cord injury. Transplantation resulted in new axons growing at the transplant site, implying the possible existence of interneuron bridging across the injured spinal cord.

Incarcerated herniation of the cervical spinal cord after laminectomy for an ossification of the yellow ligament.

A 74-year-old man showed a spastic gait and myelopathy in both the hands. Computed tomography revealed an OPLL on C3 and C4, bony spurs on the dorsal side of C4-C6, and an OYL on C3 and C4. We scheduled a two-stage decompression for both the OPLL and OYL. First, we performed laminectomy on the C3-C6 segments and resected the OYL. We did not observe any dural tear or CSF leakage in the dura. The patient's neurological symptoms improved. After the laminectomy, his myelopathy recurred. Postoperative MRI showed a spinal cord herniation. We had the C3/4 anterior cervical disectomy and fusion as we planned. In addition, we performed a surgery to repair the damaged dura mater at the site of spinal cord herniation at the same second surgery. The integrity of the arachnoid membrane was preserved. The patient's myelopathy gradually improved. There have been no reports on postoperative neurological deterioration caused by spinal cord herniation associated with a dural defect at the laminectomy site, without dural tear in the surgery after the resection of a posteriorly located cervical OYL. The possibility of a dural defect in OYL cases should be considered when planning a laminectomy for the resection of the OYL.

Bilateral interlaminar fenestration and unroofing for the decompression of nerve roots by using a unilateral approach in lumbar canal stenosis.

BACKGROUND: Conventional laminectomy is a simple procedure that provides adequate decompression in cases of lumbar spinal canal stenosis. However, with this surgical modality, important posterior osteoligamentous elements necessary for spinal stability are lost; and it is often accompanied by damage to the facet joint. Bilateral interlaminar fenestration and unroofing of the intervertebral foramen to achieve decompression of the nerve roots by using a unilateral microsurgical approach in lumbar spinal canal stenosis are less invasive compared with conventional laminectomy. METHODS: We carried out bilateral interlaminar fenestration and unroofing of the intervertebral foramen to decompress the stenosed nerve roots under a microscope by using a unilateral approach. In particular, we performed the decompression of the contralateral nerve root with this surgical method by using a Caspar retractor. Surgery was performed on 47 patients (18 women and 29 men; 29-85 years; median age, 62 years). All cases were with single-level lumbar spinal canal stenosis and bilateral radiculopathy. RESULTS: The mean preoperative NCOS was 29.8 (range, 8-48). The mean NCOS after a postoperative period of 3 months was 79.9 (range, 32-100). After a postoperative period of 2 years, the mean NCOS increased to 83.2 (range, 32-100). The satisfaction measures indicated that the procedure was "very successful" in 45 cases, providing "almost complete relief"; "fairly successful" in one case, providing "a good deal of relief"; and "not very successful" in another case, affording "only a little relief." CONCLUSIONS: This unilateral, minimally invasive decompression provided satisfactory results.

Percutaneous laser disc decompression for lumbar disc hernia: indications based on Lasegue's Sign.

OBJECTIVE: The present study was conducted to establish reasonable indications of patient neurological manifestations for use of percutaneous laser disc decompression (PLDD). BACKGROUND DATA: PLDD is a less invasive surgical procedure for lumbar disc hernia, whose indications have been described on the basis of radiographical findings. METHODS: Sixty-five consecutive patients (45 men and 20 women) with lumbar disc hernia were treated with PLDD by applying a diode laser (wavelength 805 nm). A total of 450-1,205 joules (average, 805.5 joules) were delivered per disc. All patients suffered from radicular pain. They were divided based on the presence of Lasegue's sign. The post-procedure results at 1 week and 1 year were compared between the groups. RESULTS: PLDD was effective for patients with Lasegue's sign (80.0%), but ineffective for those without the sign. CONCLUSION: The present study suggests that Lasegue's sign in patients is an indication of PLDD for lumbar disc hernia.

Report of a familial case of proatlas segmentation abnormality with late clinical onset.

Although proatlas segmentation abnormalities as developmental remnants around the foramen magnum have been reported in postmortem studies, they are rarely documented in a clinical setting. This report details the clinical and radiological characteristics of a rare case of proatlas segmentation abnormalities with clinical onset during the seventh decade of life. This case was suspected to have a familial factor. We also review the literature regarding this condition.

Promotion of astrocytoma cell invasion by micro RNA-22 targeting of tissue inhibitor of matrix metalloproteinase-2.

OBJECTIVE Diffuse astrocytomas (DAs) have a high recurrence rate due to diffuse infiltration into the brain and spinal cord. Micro RNAs (miRNAs) are small noncoding RNAs that regulate gene expression by binding to complementary sequences of target messenger RNA (mRNA). It has been reported that miRNA-22 (miR-22) is involved in the invasion of some cancer cell lines. The aim of this study was to identify the biological effects of miR-22 in regard to the invasion of human DAs. METHODS The authors evaluated whether the level of miR-22 is elevated in human spinal DAs by using miRNA chips. Next, the role of miR-22 in 1321N1 human astrocytoma cells was investigated. Finally, to elucidate whether miR-22 promotes invasion by astrocytoma cells in vivo, the authors transplanted miR-22 overexpressed astrocytoma cells into mouse thoracic spinal cord. RESULTS The miR-22 significantly upregulated the invasion capacity of 1321N1 cells. Computational in silico analysis predicted that tissue inhibitor of matrix metalloproteinase-2 (TIMP2) is a target gene of miR-22. This was confirmed by quantitative reverse transcription polymerase chain reaction and Western blotting, which showed that miR-22 inhibited TIMP2 mRNA and protein expression, respectively. Luciferase reporter assays demonstrated that miR-22 directly bound the 3'-untranslated regions of TIMP2. The authors further showed that miR-22 promoted invasiveness in 1321N1 astrocytoma cells when transplanted into mouse spinal cord. CONCLUSIONS These data suggest that miR-22 acts to regulate invasion of 1321N1 astrocytoma cells by targeting TIMP2 expression. Additional studies with more cases and cell lines are required to elucidate the findings of this study for a novel treatment target for spinal DAs.

Medical application of an infrared free-electron laser: selective removal of cholesterol ester in carotid artery atheromatous plaques.

OBJECT: . The purpose of this study was to determine the effectiveness of infrared free-electron laser (FEL) irradiation of cholesterol esters in human carotid artery (CA) atheromas. METHODS: The degradation of cholesterol ester was estimated from changes in the infrared absorption spectra acquired using microscopic transmission Fourier transform infrared spectroscopy. An FEL emitting radiation at 5.75-microm wavelengths and a power density of 15.9 W/cm2 was used to treat intimal slices of extirpated human arterial atherosclerotic plaques. Peak signals derived from an ester bond of cholesterol ester decreased in height as irradiation time increased and disappeared completely after 180 seconds. No other change was observed in the infrared absorption spectrum after 180 seconds of irradiation, and no histological damage was noted. CONCLUSIONS: The authors concluded that FEL irradiation can remove cholesterol ester selectively from human atheromatous CA plaques. This novel technique differs from previous approaches involving conventional lasers.

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.

Radiological Evaluation of the Initial Fixation between Cortical Bone Trajectory and Conventional Pedicle Screw Technique for Lumbar Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective study. PURPOSE: To compare initial fixation using the cortical bone trajectory (CBT) technique versus conventional pedicle screws (PS) in radiographs of postsurgical lumbar degenerative spondylolisthesis. OVERVIEW OF LITERATURE: Few reports have documented the holding strength of CBT technique for spondylolisthesis cases. METHODS: From October 2009 to June 2014, 21 cases of degenerative spondylolisthesis were surgically treated in our institution. Ten were treated with conventional PS technique and 11 of with CBT technique. Mean lumbar lordosis and percent slippage were evaluated preoperatively, immediately after surgery, and 6 months and 1 year postoperatively using radiographs. We also investigated percent loss of slip reduction. RESULTS: There were statistically significant differences between preoperative percent slippage and postoperative slippage in both PS and CBT procedures over 1 year, and both techniques showed good slip reduction. On the other hand, lumbar lordosis did not change significantly in either the PS or CBT groups over 1 year. CONCLUSIONS: CBT technique showed similarly good initial fixation compared with the PS procedure in the treatment of lumbar degenerative spondylolisthesis.

Significance of the Pars Interarticularis in the Cortical Bone Trajectory Screw Technique: An In Vivo Insertional Torque Study.

STUDY DESIGN: Retrospective study. PURPOSE: Cortical bone trajectory (CBT), a more medial-to-lateral and shorter path than the traditional one for spinal fusion, is thought to be effective for severely degenerated vertebrae because screws are primarily stabilized at the posterior elements. We evaluated the efficacy of this approach through in vivo insertional torque measurement. OVERVIEW OF LITERATURE: There has been only one prior in vivo study on CBT insertional torque. METHODS: Between January 2013 and April 2014, a total of 22 patients underwent posterior lumbar fusion using the CBT technique. The maximum insertional torque, which covers the radial strength needed for insertion, was measured for 113 screws, 8 of which were inserted for L5 spondylolysis. The insertional torque for cases with (n=8) and without (n=31) spondylolysis of L5 were compared using one-way analysis of variance (ANOVA). To evaluate vertebral degeneration, we classified 53 vertebrae without spondylolysis by lumbar radiography using semiquantitative methods; the insertional torque for the 105 screws used was compared on the basis of this classification. Additionally, differences in insertional torque among cases grouped by age, sex, and lumbar level were evaluated for these 105 screws using ANOVA and the Tukey test. RESULTS: The mean insertional torque was significantly lower for patients with spondylolysis than for those without spondylolysis (4.25 vs. 8.24 in-lb). There were no statistical differences in insertional torque according to vertebral grading or level. The only significant difference in insertional torque between age and sex groups was in men <75 years and women ≥75 years (10 vs. 5.5 in-lb). CONCLUSIONS: Although CBT should be used with great caution in patient with lysis who are ≥75 years, it is well suited for dealing with severely degenerated vertebrae because the pars interarticularis plays a very important role in the implementation of this technique.

"Do Not Follow the Tail": A Practical Approach to Remove a Sheared Lumbar Catheter Fragment Avoiding Its Migration into the Spinal Canal.

BACKGROUND: Catheter shearing is one of the most common complications of various neurosurgical modalities that use an intrathecal lumbar catheter. The sheared catheter fragment often can spontaneously migrate into the spinal canal; however, in some cases, the end of the fragment will remain outside the spinal canal. In this situation, the consulting neurosurgeons may try to retrieve the catheter fragment by approaching it directly through the catheter tract. This simple maneuver, however, can cause the fragment to slip into the spinal canal before it is secured, as we experienced recently in 2 cases. Because the fragment of the sheared catheter slipped while manipulating it within the catheter tract, we suggest that surgeons not approach the fragment along the tract to prevent it from migrating downward. METHODS: Using the operative findings of an illustrative case, we describe how to avoid downward migration of the catheter fragment when retrieving a sheared lumbar catheter. RESULTS: We found that the sheared catheter of a lumbar-peritoneal shunt was slowly slipping along with the pulsatile movement of cerebrospinal fluid within the catheter tract. We successfully retrieved the fragment by approaching it from outside the catheter tract. CONCLUSIONS: We propose that surgeons approach the fragment from outside of the catheter tract. One should keep in mind a simple phrase, 'Do not follow the tail', when retrieving the sheared lumbar catheter fragment.

A Pilot Clinical Study of Olfactory Mucosa Autograft for Chronic Complete Spinal Cord Injury.

Recent studies of spinal cord axon regeneration have reported good long-term results using various types of tissue scaffolds. Olfactory tissue allows autologous transplantation and can easily be obtained by a simple biopsy that is performed through the external nares. We performed a clinical pilot study of olfactory mucosa autograft (OMA) for chronic complete spinal cord injury in eight patients according to the procedure outlined by Lima et al. Our results showed no serious adverse events and improvement in both the American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade and ASIA motor score in five patients. The preoperative post-rehabilitation ASIA motor score improved from 50 in all cases to 52 in case 2, 60 in case 4, 52 in case 6, 55 in case 7, and 58 in case 8 at 96 weeks after OMA. The AIS improved from A to C in four cases and from B to C in one case. Motor evoked potentials (MEPs) were also seen in one patient, reflecting conductivity in the central nervous system, including the corticospinal tract. The MEPs induced with transcranial magnetic stimulation allow objective assessment of the integrity of the motor circuitry comprising both the corticospinal tract and the peripheral motor nerves.We show the feasibility of OMA for chronic complete spinal cord injury.

Motor evoked potential and voluntary EMG activity after olfactory mucosal autograft transplantation in a case of chronic, complete spinal cord injury: case report.

The efficacy of olfactory mucosal autografts (OMAs) for chronic spinal cord injury (SCI) has been reported, but there is no report documenting electrophysiological conductivity via the emergence of motor evoked potentials (MEPs). We report the case of a 39-year-old man with chronic, complete SCI at T8, who exhibited MEPs after OMA transplantation, and, with intensive rehabilitation, was ultimately able to ambulate with short leg braces and Lofstrand crutches. The initial injury occurred in a motor vehicle accident in November 1999 and resulted in a complete loss of sensorimotor function below T8. OMA transplantation to the injury site was performed in March 2010 in combination with intensive pre- and postoperative rehabilitation. The patient exhibited voluntary electromyograph (EMG) activity and MEPs at 96 and 144 weeks after transplantation and he was was ambulatory with short leg braces and Lofstrand crutches at 144 weeks after transplantation. We were able to elicit MEPs after OMA with intensive rehabilitation. To our knowledge, this is the first report of recovery of electrophysiological conductivity in the spinal cord after any type of treatment for chronic, complete SCI.