Remodeling of Epidural Fluid Hematoma after Uniportal Lumbar Endoscopic Unilateral Laminotomy with Bilateral Decompression: Comparative Clinical and Radiological Outcomes with a Minimum Follow-up of 2 Years

Methods@#Magnetic resonance imaging (MRI) and clinical evaluation were performed for patients with single-level uniportal endoscopic lumbar decompression with a minimum follow-up of 2 years. @*Results@#A total of 126 patients were recruited with a minimum follow-up of 26 months. The incidence of epidural fluid hematoma was 27%. Postoperative MRI revealed a significant improvement in the postoperative dura sac area at postoperative day 1 and at the upper endplate at 6 months in the hematoma cohort (39.69±15.72 and 26.89±16.58 mm2) as compared with the nonhematoma cohort (48.92±21.36 and 35.1±20.44 mm2), respectively (p <0.05); and at the lower endplate on postoperative 1 day in the hematoma cohort (51.18±24.69 mm2) compared to the nonhematoma cohort (63.91±27.92 mm2) (p <0.05). No significant difference was observed in the dura sac area at postoperative 1 year in both cohorts. The hematoma cohort had statistically significant higher postoperative 1-week Visual Analog Scale (VAS; 3.32±0.68) pain and Oswestry Disability Index (ODI; 32.65±5.56) scores than the nonhematoma cohort (2.99±0.50 and 30.02±4.84, respectively; p <0.05). No significant difference was found at the final follow-up VAS, ODI, and MRI dura sac area. @*Conclusions@#Epidural fluid hematoma is a common early postoperative MRI finding in lumbar endoscopic unilateral laminotomy with bilateral decompression. Conservative management is the preferred treatment option for patients who do not have a neurological deficit. Symptoms last only a few days and are self-limiting. A common endpoint is a remodeled fluid hematoma and the subsequent expansion of the dura sac area.

Narrative Review of Pathophysiology and Endoscopic Management of Basivertebral and Sinuvertebral Neuropathy for Chronic Back Pain

Chronic lower back pain is a leading cause of disability in musculoskeletal system. Degenerative disc disease is one of the main contributing factor of chronic back pain in the aging population in the world. It is postulated that sinuvertebral nerve and basivertebral nerve main mediator of the nociceptive response in degenerative disc disease as a result of neurotization of sinuvertebral and basivertebral nerve. A review in literature is done on the pathoanatomy, pathophysiology and pain generation pathway in degenerative disc disease and chronic back pain and management strategy is discussed in this review to aid understanding of sinuvertebral and basivertebral neuropathy treatment strategies.

Prospective Cohort Study with a 2-Year Follow-up of Clinical Results, Fusion Rate, and Muscle Bulk for Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion

Methods@#We evaluated patients who underwent EPTLIF with a minimum 24-month follow-up. Clinical parameters of the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were measured at the preoperative, 1-week postoperative mark, postoperative 3-month mark, and final follow-up. Preoperative and 1-year postoperative magnetic resonance imaging measurement of preoperative and postoperative Kjaer grade, right and left psoas muscle mass area, and right and left paraspinal muscle mass area was performed. @*Results@#EPTLIF with a minimum 24-month follow-up of 35 levels was included. The complication rate was 6%, and the mean Bridwell’s fusion grade was 1.37 (1–2). There was statistically significant improvement at 1 week, 3 months, and 2 years in VAS (4.11±1.23, 4.94±1.30, and 5.46±1.29) and in ODI (40.34±10.06, 46.69±9.14, and 49.63±8.68), respectively (p <0.05). Successful operation rate with excellent and good MacNab’s criteria at 2 years was 97%. There was an increment of statistically significant bilateral psoas muscle cross-sectional area, right side (70.03±149.1 mm²) and left side (67.59±113.2 mm²) (p <0.05). @*Conclusions@#Uniportal EPTLIF achieved good fusion and improved clinical outcomes with favorable paraspinal musculature bulk at the 2-year follow-up.

Transient paralysis by loculation of the injectant associated with epidural injection

@#Transient paralysis occasionally occurs after an epidural injection, but the reasons for this are still unknown. We present here a patient with transient paralysis following loculation of the injectant associated with the procedure. A 50-year-old woman with a history of two previous spinal operations complained of a burning sensation and radiating pain. A caudal block and right S1 transforaminal epidural block were performed. Loculation of the block injectant into the right L5 and S1 epidural space was confirmed through computed topographic imaging. She showed transient weakness of the right lower limb, which completely recovered after 1 day. This case shows that extra care should be taken when performing an epidural injection in a patient with adhesions around the injection site and appropriate adjustments should be made to the volume of the injectant.

Pusher syndrome improved by secondary newly developed stroke

@#Pusher syndrome is a neurological disorder where the patient actively pushes away from the non-hemiparetic side following brain damage. We experienced a case in whom intractable pusher syndrome associated with thalamic hemorrhage improved following a newly developed pontine infarction. A 63-year-old man showed severe pusher syndrome after an initial thalamic hemorrhage. After approximately 2 years, a pontine infarction developed and improved the persistent pusher syndrome. We postulate that it resulted from involvement of the medial lemniscus with interruption of the distorted upward proprioceptive signal of body orientation.

Analysis of Adjacent Fractures after Two-Level Percutaneous Vertebroplasty: Is the Intervening Vertebral Body Prone to Re-fracture?

STUDY DESIGN: Retrospective study. PURPOSE: This retrospective study aimed to determine the incidence of adjacent level new fractures in a sandwich constellation (one or two untreated vertebrae between two cemented vertebrae) compared with that in other constellations formed by two-level percutaneous vertebroplasty (PVP). It also aimed to investigate the potential factors contributing to adjacent new fractures in a sandwich constellation. OVERVIEW OF LITERATURE: There are few studies regarding the intervening intact vertebral body between two cemented vertebrae. Clinical data from previous studies investigation this sandwich situation, too, have been vague. METHODS: Clinical data were obtained from 132 patients who had two cemented vertebral bodies, irrespective of whether they had undergone one or two PVP sessions between January 2013 and June 2016 at a single institution. Cases with one or two intact vertebral levels between the two cemented vertebrae were classified into group 1 (n=47), and cases with two consecutive cemented bodies or more than three levels of intervening configurations were classified into group 2 (n=85). Demographic data and radiological parameters for new fractures after PVP were compared between the two groups, and the rates of subsequent adjacent fractures were investigated. RESULTS: The incidence of single-level sandwich constellations was quite uncommon (7.7%). The overall incidences of adjacent fracture were 29.8% (14/47) in group 1 and 14.1% (12/85) in group 2. This difference was statistically significant (p=0.03). Approximately 80% (11/14) of the adjacent new fractures in group 1 developed at an intervening level. The patient demographics and radiological parameters for subsequent fractures after PVP did not statistically correlate with the risk of adjacent new fractures in group 1. CONCLUSIONS: Because they were subjected to double-load shifts, sandwich constellations were prone to re-fractures after PVP. These vertebral configurations required more aggressive management for osteoporosis.

Postoperative Clinical Outcome and Risk Factors for Poor Outcome of Foraminal and Extraforaminal Lumbar Disc Herniation

OBJECTIVE: We evaluated postoperative outcomes in patients who have lumbar foraminal or extraforaminal disc herniation (FELDH) and suggested the risk factors for poor outcomes. METHODS: A total of 234 patients were selected for this study. Pre- and post-operative Visual Analogue Scale (VAS) and Korean version Oswestry Disability Index (KODI) were evaluated and the changes of both score were calculated. Outcome was defined as excellent, good, fair, and poor based on Mcnab classification. The percentage of superior facetectomy was calculated by using the Maro-view 5.4 Picture Archiving Communication System (PACS). RESULTS: Paramedian lumbar discectomy was performed in 180 patients and combined lumbar discectomy was performed in 54 patients. Paramedian lumbar discectomy group showed better outcome compared with combined discectomy group. p value of VAS change was 0.009 and KODI was 0.013. The average percentage of superior facetectomy was 33% (range, 0-79%) and it showed negative correlation with VAS and KODI changes (Pearson coefficient : -0.446 and -0.498, respectively). Excellent or good outcome cases (Group I) were 136 (58.1%) and fair or poor outcome cases (Group II) were 98 (41.9%). The percentage of superior facetectomy was 26.5% at Group I and 42.5% at Group II. There was significant difference in superior facetectomy percentage between Group I and II (p=0.000). CONCLUSION: This study demonstrated that paramedian lumbar discectomy with preservation of facet joints is an effective and good procedure for FELDH. At least 60% of facet should be preserved for excellent or good outcomes.

Combined Interlaminar and Paraisthmic Approach for Co-existing Intracanal and Foraminal Lesion

OBJECTIVE: Stenosis or herniated nucleus pulposus (HNP) occupying lumbar intracanal and foraminal area is an important cause of double radicular symptoms. Using the combined interlaminar and paraisthmic approach, we performed decompression surgery in patients with co-existing intracanal and foraminal lesions. The objective of this study is to describe usefulness and outcome of combined interlaminar and paraisthmic approach surgery and to analysis the cause of poor outcome. METHODS: Between Apr 2009 and Apr 2014, 78 patients (42 males and 36 females) with intracanal and foraminal lesions were enrolled in this study. Patients with a vacuum disc, spondylolisthesis, instability or an isthmic defect on the preoperative dynamic view radiograph were excluded from this study. All patients underwent surgery through a combined approach for discectomy and decompression. The outcome of surgery was evaluated and classified into excellent, good, fair and poor. RESULTS: The results were excellent in 53 patients, good in 9, fair in 6 and poor in 10 during the follow-up. The outcome of the combined approach was excellent to fair in 87% (68 of 78) patients in our study. In the poor outcome group, three patients complained of early-onset relapsed pain (3 months). CONCLUSION: Combined approach for both intracanal and foraminal area lesions may be useful if selectively performed on patients whose facet joint is relatively intact, and that it is worthy of consideration as an alternative to fusion surgery; however, further studies are needed.

Influence of Alendronate and Endplate Degeneration to Single Level Posterior Lumbar Spinal Interbody Fusion

OBJECTIVE: Using alendronate after spinal fusion is a controversial issue due to the inhibition of osteoclast mediated bone resorption. In addition, there are an increasing number of reports that the endplate degeneration influences the lumbar spinal fusion. The object of this retrospective controlled study was to evaluate how the endplate degeneration and the bisphosphonate medication influence the spinal fusion through radiographic evaluation. METHODS: In this study, 44 patients who underwent single-level posterior lumbar interbody fusion (PLIF) using cage were examined from April 2007 to March 2009. All patients had been diagnosed as osteoporosis and would be recommended for alendronate medication. Endplate degeneration is categorized by the Modic changes. The solid fusion is defined if there was bridging bone between the vertebral bodies, either within or external to the cage on the plain X-ray and if there is less than 5degrees of angular difference in dynamic X-ray. RESULTS: In alendronate group, fusion was achieved in 66.7% compared to 73.9% in control group (no medication). Alendronate did not influence the fusion rate of PLIF. However, there was the statistical difference of fusion rate between the endplate degeneration group and the group without endplate degeneration. A total of 52.4% of fusion rate was seen in the endplate degeneration group compared to 91.3% in the group without endplate degeneration. The endplate degeneration suppresses the fusion process of PLIF. CONCLUSION: Alendronate does not influence the fusion process in osteoporotic patients. The endplate degeneration decreases the fusion rate.

Clinical and Radiologic Analysis of Posterior Apophyseal Ring Separation Associated with Lumbar Disc Herniation

OBJECTIVE: We analyzed the clinical and radiologic features of posterior apophyseal ring separation (PARS) with lumbar disc herniation and suggest the proper management options according to the PARS characteristics. METHODS: We reviewed case series of patients with PARS who underwent surgery of lumbar disc herniation. Preoperative symptoms, neurologic status, Body Mass Index, preoperative and postoperative Visual Analogue Scale (VAS) and Korean-Oswestry Disability Index (K-ODI) scores, operation types were obtained. PARS size, locations, the degree of resection were assessed. RESULTS: PARS was diagnosed in 109 (7.5%) patients among 1448 patients given surgical treatment for single level lumbar disc herniation. There were 55 (50.5%) small PARS and 54 (49.5%) large PARS. Among the large PARS group, 15 (27.8%) had lower endplate PARS of upper vertebra at the level of disc herniation. Thirty-nine (72.2%) were upper endplate PARS of lower vertebra. Among the group with upper endplate PARS of lower vertebra, unresected PARS was diagnosed in 12 (30.8%) cases and resected PARS was diagnosed in 27 (69.2%) cases. VAS and K-ODI scores changes were 3.6+/-2.9 and 5.4+/-6.4 in the unresected PARS group, 5.8+/-2.1 and 11.3+/-7.1 in the resected PARS group. The group with upper endplate PARS of lower vertebra showed significant difference of VAS (p=0.01) and K-ODI (p=0.013) score changes between unresected and resected PARS groups. CONCLUSION: The large PARS of upper endplate in lower vertebra should be removed during the surgery of lumbar disc herniation. High level or bilateral side of PARS should be widely decompressed and arthrodesis procedures are necessary if there is a possibility of secondary instability.

The Clinical Characteristics of Lower Lumbar Osteoporotic Compression Fractures Treated by Percutaneous Vertebroplasty : A Comparative Analysis of 120 Cases

OBJECTIVE: The purpose of this study is to provide accurate understanding of clinical presentations and surgical outcomes as well as to identify the unique characteristics of lower lumbar osteoporotic compression fracture (OCF). METHODS: Clinical data were collected from 120 patients who had L3, L4 or L5 percutaneous vertebroplasty (PVP) performed from 2008 to 2012 at the single institute. L4 or L5 PVP patients were classified into group 1 and group 2 was for L3 PVP patients. Medical records were retrospectively investigated at 1 month after PVP. Long term follow-up results were obtained at a median value of 22 months after PVP. RESULTS: 75% of the patients in group 1 were not associated with traumatic events, 71% presenting with leg radiating symptoms and 46% requiring an additional decompressive surgery, more often than those in group 2. These differences are statistically significant (p<0.05). The short term medical record review demonstrated that only 73% of patients in group 1 were ameliorated with regard to back motion pain, whereas those in group 2 reported 87.7% rates of amelioration in identical category (p<0.05). The long term follow up confirmed a significantly worse outcome in group 1, with only 55.7% of patients reporting amelioration in their pain or functional status, but 71.7% rate of amelioration in group 2. CONCLUSION: The OCFs at the L4 or L5 level have different clinical characteristics from those at upper levels of the lumbar spine.

Recurrence Rate after Herniotomy only versus Discectomy in Lumbar Disc Herniation

OBJECTIVE: Lumbar disc herniation (LDH) recurrence necessitating reoperation can pose problems following spinal surgery, with an overall reported incidence of approximately (3-13%). The purpose of this study is to identify the rate of recurrent disc herniation, to discuss the radiologic indications for herniotomy and to analyze clinical outcomes compared with conventional discectomy. METHODS: This study is a retrospective case control study. The authors retrospectively reviewed 114 patients who underwent herniotomy & conventional discectomy by a single surgeon for single-level LDH between June 2009 and May 2012. Herniotomy group was 57 patients and conventional discectomy group was 57 patients that were selected from 631 patients using stratified randomization. Evaluation for LDH recurrence included detailed medical chart and radiologic review and telephone interview. Postoperative VAS and the Korean version of ODI were examined one week after surgery. Clinical outcome was investigated according to Odom's criteria from three months to three years. RESULTS: Of the 114 patients for whom the authors were able to definitively assess symptomatic recurrence status, four patients (7%) experienced LDH recurrence following single-level herniotomy and three patients (5.2%) conventional discectomy. There were no differences in the VAS and Korean version of ODI between herniotomy group and conventional discectomy group. The herniotomy group had better results than the conventional discectomy group in clinical outcome from three months to three years, but the difference was not significant. CONCLUSION: There were no significant differences in clinical outcome between herniotomy and conventional discectomy. Recurrence rates following herniotomy for LDH compare favorably with those in patients who have undergone conventional discectomy, lending further support for its effectiveness in treating herniotomy.

Is the Cross-sectional Area after Unilateral Open Door Laminoplasty Wider than that after Midline Splitting Laminoplasty ? : Mathematical Approach

OBJECTIVE: The aim of this study was to compare geometrically cross-sectional areas of two different laminoplasty techniques in same opening size. Some investigators have studied the expanded areas of the two different techniques using imaging study. Although it is unclear that postoperative spinal canal is correlated with the surgical outcome we just focused on mathematical and geometrical correlation of the expandable area with surgical opening size in different laminoplasty techniques. METHODS: To predict the expandable area by a midline splitting technique and a unilateral open door technique, we placed an imaginary isosceles triangle in the spinal canal and drew graphs for the equation of the expandable areas in same opening size using the Pythagorean theorem and mathematical program. To substitute the constant figures of mathematical formula we estimated the normal cervical spine CT scans of 50 Korean adults. RESULTS: We subtracted the imaginary triangle from the spinal canal and were left with the remaining area of the spinal canal that was not changed before and after surgery. In same opening size the expandable area by the midline splitting technique was same but slightly wider than the unilateral open door technique, irrespective of the triangular shape. For a normal isosceles triangle the results were the same. CONCLUSION: Using mathematical proof, the expandable area after the midline splitting technique was same but slightly larger than that after the unilateral open door technique, irrespective of the size of the lamina opening.

Instrumented Fusion of Same-Level Lamina and Transverse Process for the Treatment of Lumbar Spondylolysis: A Preliminary Report

OBJECTIVE: There were many instruments introduced for direct repair of spondylolysis. But those instruments were not designed for direct repair of spondylolysis originally. Dynesys implants consist of pedicle screws and cords or laminar hooks that were designed for lumbar dynamic stabilization. We used pedicle screws and cord or laminar hook of Dynesys spinal system for repairment of spondylolysis. METHODS: July 2005 to March 2009, Six patients with lumbar spondylolysis were treated with a new technique using a pedicle screw with a u-shaped rod or laminar hook combined with bone grafting of the transverse process and lamina of the same level, bypassing the spondylolytic defect. There were 5 males and 1 female. Ages ranged from 18-48 years(average of 34.5 years). A total of 8 vertebral levels were fused(one patient had spondylolytic defects at 3 levels). Five defects were at L5, two at L4, and one at L3. The patients had low back pain that was unimproved after 3-6 months of conservative management. None demonstrated spondylolisthesis or instability, disc degeneration on MRI, nor radiculopathy. All symptoms resolved after isthmus block. The patients were followed-up for a period of 3-27 months(average of 14.8 months). The authors compared pre-operative and post-operative clinical symptoms and radiographic findings retrospectively. Success of the procedure was determined by the following criteria: impro- vement of clinical symptoms(VAS score), absence of isthmic motion on plain radiographs, and evaluation for the presence of a bone mass bridging the transverse processes and laminae using plain radiographs and reconstruction CT scan. RESULTS: All patients demonstrated improvement in pain scores(average of 8.3 to an average of 3.2). A fusion rate of 87.5% was achieved(7 out 8 levels). No complications were noted. The authors were able to demonstrate a potential benefit in using this new technique for the treatment of lumbar spondylolysis. CONCLUSION: Direct repair of spondylolysis with Dynesys spinal system is technically easy and fixes strongly biome- chanically.

Early Radiological Analysis of Cervical Arthroplasty with Bryan and Mobi-C Cervical Disc Prosthesis

OBJECTIVE: We investigated whether there are any different results in the overall sagittal alignment, neutral functional spine unit (FSU) angle and segmental FSU ROM (range of motion) angle from the patients undergone by cervical arthroplasty with two kinds of artificial cervical disc prostheses, Bryan and Mobi-C cervical disc. METHODS: Twenty eight patients underwent anterior cervical discectomy and implantation of artificial cervical disc prosthesis; Eighteen of them underwent operation with Bryan and the rest of them with Mobi-C cervical disc prosthesis. These patients consist of fourteen females and fourteen males with mean age 46.9 years old and 9.4 months mean follow-up period. There were 4 cases of C 4-5, 18 cases of C 5-6 and 6 cases of C 6-7 level. We measured overall sagittal alignment, neutral FSU angle and segmental FSU ROM angle using lateral radiographs preoperatively and postoperatively. The clinical outcome was evaluated by neck disability index(NDI). RESULT: The average angle of overall sagittal alignments was changed from -17.45degrees preoperatively to -14.21degrees postoperatively in Bryan cervical disc group. It decreased 3.24degrees in cervical lordosis. However, in Mobi-C cervical disc group, the average angle of overall sagittal alignments was changed from -10.33degrees preoperatively to -16.89degrees postoperatively. It increased 6.56degrees in cervical lordosis. The averages of neutral FSU angles were -1.14degrees preoperatively and -3.26degrees postoperatively in Bryan cervical disc group, and were -0.93degrees preoperatively and -9.7degrees postoperatively in Mobi-C cervical disc group. The averages of segmental FSU ROM angles were 11.18degrees preoperatively and 10.61degrees postoperatively in Bryan cervical disc group, and was 8.31degrees preoperatively and 13.6degrees postoperatively in Mobi-C cervical disc group. NDIs were 24.0 preoperatively and 5.9 postoperatively in Bryan cervical disc group, and 24.7 preoperatively and 8.7 postoperatively in Mobi-C cervical disc group. CONCLUSION: Postoperative cervical lordosis and segmental FSU ROM angle were increased in Mobi-C cervical disc group (p<0.05). To preserve segmental motion and avoid adjacent segment degeneration is to the focus in cervical arthroplasty. To preserve cervical lordosis after operation is physiologic than postoperative cervical kyphosis. It remains controversial whether cervical kyphosis influences clinical outcome after anterior cervical operation. The results of this study show that the technical and mechanical improvement of Bryan cervical disc prosthesis may be considered.

Decompressive Surgery Alone for Lumbar Spinal Stenosis in Elderly Patients

OBJECTIVE: The authors conducted this study to investigate the safety and efficacy of decompressive surgery alone in the treatment of lumbar spinal stenosis in the elderly population. METHODS: All charts and records of 323 patients aged 65 years or older who underwent lumbar spinal decompressive surgery without fusion for lumbar spinal stenosis in the period from September 2003 to August 2007 were reviewed. RESULTS: A total of 323 patients were identified. Mean age among patients were 72.6years. 197 patients(60.9%) underwent wide decompression, 95 patients(29.4%) had microscopic partial decompression, and 31 patients(9.5%) underwent bilateral decompression via unilateral approach. Perioperative morbidity seen was among 16 patients(4.9%). There were 5 patients(1.5%) reoperated for hematoma formation. Another 5 patients(1.5%) developed wound infection. Cerebrospinal fluid(CSF) leakage were noted among 3 patients(0.9%). 2 patients(0.6%) had urinary difficulty, and Steven Johnson syndrome developed in one patient(0.3 %). Clinical outcome was evaluated using Macnab's classification. 40 patients(12.4%) had excellent results, 241 patients(74.8%) had good results, 34 patients(10.3%) had fair results and 8 patients(2.5%) had poor outcome. CONCLUSION: Decompressive laminectomy alone is a relatively safe and effective treatment option for the elderly.

The effect of Methylprednisolone on Energy Metabolism in Acute Experimental Ischemia

The purpose of this study is to investigate the effect of methylprednisolone(M.P.) on the alterations of ATP, sum of adenosine nucleotides, adenylate energy charge(E.C.), glucose and lactate in the cats with acute focal ischemic cerebral edema. The acute occlusion of left middle cerebral artery(MCA) of forty cats for 1,3 and 5 hours respectively were accomplished by applying Heifetz clip through the transorbital approach operating microscope. Twelve cats were not recirculated as a untreated group, twelve cats were recirculated for 2 hours as a ecirculation group and twelve cats were recirculated for 2 hours and given M.P.(15mg/kg) at 30 minutes after occlusion initially, and then every one and a half hour as a treatment group. The experimental results are as follows. 1) In 1-hour untreated group, ATP was reduced to 34.0%, sum of adenosine nucleotides reduced to 72.2%, adenylate E.C. reduced to 60.6%, glucose reduced to 67.3% and lactate increased to 156.6% of the control value. In the recirculation group, ATP was reduced to 42.0%, sum of adenosine nucleotides reduced to 82.4%, adenylate E.C. reduced to 74.3%, glucose increased to 552.7% and lactate decreased to 79.8%. In the treatment group, ATP was increased to 143.9%, sum of adenosine nucleotides increased to 153.9%, adenylate E.C. decreased to 92.9%, glucose increased to 3334.5% and lactate decreased to 74.6%. 2) In 3-hour untreated group, ATP was decreased to 24.9%, sum of adenosine nucleotides reduced to 22.9%, adenylate E.C. reduced to 58.6%, glucose decreased to 45.5% and lactate increased to 161.3% of the control value. In the recirculation group, ATP reduced to 32.9%, sum of adenosine nucleotides reduced to 28.6%, adenylate E.C. reduced to 71.4%, glucose rose to 520.0% and lactate to 135.3% of the control value. In the treatment group, ATP reduced to 99.5%, sum of adenosine nucleotides increased to 103.5%, adenylate E.C. decreased to 84.3%, glucose rose to 1187.3% and lactate increased to 101.2%. 3) In 5-hour untreated group, ATP decreased to 5.3%, sum of adenosine nucleotides reduced to 9.0%, adenylate E.C. reduced to 58.6%, glucose decreased to 25.5% and lactate increased to 187.9%. In the recirculation group, ATP decreased to 4.4%, sum of adenosine nucleotides decreased to 5.8%, adenylate E.C. decreased to 57.1%. In the treatment group, ATP was reduced to 11.2%, sum of adenosine nucleotides and adenylate E.C. reduced to 70.0%, glucose rose to 103.6% and lactate to 157.2% of the control value. As the results shown above, the therapeutic beneficial effects of M.P. were observed in cats of 1 or 3-hour occlusion of MCA with 2-hour recirculation.

An Experiments Study of the Effect of Ischemic Edema on Cerebral Energy Metabolism

The author studied the effect of the recirculation on the energy metabolism in acute focal cerebral ischemia. Acute focal cerebral ischemia was produced by transorbital occlusion of the left middle cerebral artery with a Heifetz clip under the operating microscope. The animals were divided into three groups according to the duration of the ischemia. Each group was reperfused for 1, 4 and 7 hour by removing the clip from the artery. In 1-hour ischemic group ATP and GTP was reduced to 38% and IMP to 40% of the sham control. After 7-hour recirculation in this group ATP was resynthesized to 85%, GTP to 85%, and IMP to 180% of the sham control. In 3-hour ischemic group ATP was reduced to 19%, GTP to 23%, and IMP to 29% of the sham control. In this group ATP, GTP and IMP rose to 43%, 49% and 84%, respectively after 7-hour recirculation ATP, GTP and IMP were markedly reduced in 5-hour ischemic group, and despite recirculation these substances continued to decrease and none of them were detected after 7-hours of recirculation, It was suggested that the restoration of the circulation must be accomplished within 1-hour or at least within 3-hour of the ischemic insult of the cats to prevent the irreversible brain infarction.