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PubMed2004

Dura-splitting decompression of the craniocervical junction: reduced operative time, hospital stay, and cost with equivalent early outcome.

OBJECT: The choice of surgical technique for decompressive surgery in patients with Chiari I malformation is controversial. Good preliminary postoperative outcomes have been achieved in patients with Chiari I malformation (without syringomyelia) after using a dura-splitting technique. The authors evaluated safety, resource use, and early outcome after this surgery in patients without syringomyelia and compared the findings associated with duraplasty in patients with syringomyelia. METHODS: A prospective series of 24 patients with Chiari I malformation (12 with a syrinx) underwent decompression of the craniocervical junction (CCJ). An allograft-augmented duraplasty was performed in patients with syringomyelia. Intraoperative ultrasonography confirmed adequate tonsillar decompression after lysis of the periosteal bands at the foramen magnum and C-1 arch as well as partial resection of the outer leaf of the dura in patients without syringomyelia. Patients in each group were of similar mean age (syringomyelia 10.8 years and no syringomyelia 7.6 years old; p = 0.07) and functional status. The mean follow-up period was 15.3 months (range 3-30 months). Dura-splitting decompression required significantly less mean operative time (99 minutes compared with 169 minutes, respectively; p < 0.001), total operating room time (166 minutes compared with 249 minutes, respectively; p < 0.001), duration of hospitalization (3 days compared with 3.75 days, respectively; p < 0.05), perioperative charges ($3615 compared with $5538, respectively; p < 0.001), and overall hospital charges ($7705 compared with $9759, respectively; p < 0.001) than the duraplasty. Mean clinical outcome scores were similar (syringomyelia 1.53 of 2; no syringomyelia 1.67 of 2; not statistically significant). CONCLUSIONS: Dura-splitting CCJ decompression in pediatric patients with Chiari I malformation and without syringomyelia is safe, provides good early clinical results, and significantly reduces resource use. A randomized controlled trial of dura-splitting decompression in a uniform population of patients with Chiari I malformation is indicated.

Adolescent↗
PubMed2005

Short-term results of microendoscopic posterior decompression for lumbar spinal stenosis. Technical note.

OBJECT: The authors applied the technique of microendoscopic discectomy to posterior decompression procedures for lumbar spinal stenosis. The purpose of this study was to determine the feasibility of using an endoscopic technique to treat lumbar spinal stenosis and to evaluate the clinical and radiographic results of microendoscopic posterior decompression (MEPD). METHODS: Microendoscopic posterior decompression, which involves a unilateral endoscopic approach for bilateral decompression, was performed in 47 patients. Clinical and radiographic/neuroimaging results were evaluated during the follow-up period (minimum duration 1 year). The clinical results were compared with those of the conventional laminotomy. Radiographic instability and the degree of surgical invasion of the facet joints were evaluated. In a control a group of 29 patients open laminotomy was performed. The clinical outcome was evaluated in 44 patients. The mean follow-up duration was 22 months. The mean rate of improvement was 72% based on the Japanese Orthopaedic Association score, and good results were obtained in 38 patients. Although the rate of morbidity decreased in the MEPD group, the incidence of complication was slightly higher. Effective decompression was demonstrated in the majority of the patients by using magnetic resonance imaging. Radiographic instability appeared in one patient postoperatively, and based on computerized tomography scanning, a tendency toward invasion of the facet joint on the approach side was noted. CONCLUSIONS: Microendoscopic posterior decompression is a minimally invasive procedure and is as useful as other conventional procedures in treating lumbar spinal stenosis; however, a few technical problems remain to be solved.

Adult↗
PubMedDate not supplied

Incidence and treatment of diplopia after three-wall orbital decompression in Graves' ophthalmopathy.

PURPOSE: To describe our experience treating diplopia after orbital decompression in patients with thyroid orbitopathy. PATIENTS AND METHODS: From May 1997 to July 2001, we performed orbital decompression on 102 patients (34 men and 68 women) with severe proptosis. In 10 (9.8%) of these patients who had no diplopia preoperatively, diplopia in primary gaze occurred after decompression. In 19 (18.6%) of the patients with diplopia in primary gaze before surgery, there was no modification of diplopia after decompression. In 24 (23.5%) of the patients with diplopia in primary gaze before surgery, a more severe imbalance occurred after decompression. Forty-four (83%) of these 53 patients underwent adjustable extraocular muscle surgery with the use of viscoelastic substances to gain single vision in primary position. In 9 (17%) of the patients, diplopia was resolved with the use of prismatic lenses. RESULTS: In 31 (70.4%) of 44 patients, we obtained a stable resolution of diplopia in primary position (minimum follow-up, 6 months). In 10 (22.7%) of these patients, a second surgery on the oblique muscles was necessary 6 months after the first surgery to resolve torsional diplopia. In 3 (6.8%) of the patients, diplopia has been resolved with prismatic lenses. CONCLUSION: Orbital decompression reduces proptosis, but may cause diplopia or worsen it.

Adult↗
PubMed2001

Efficacy of calcium sulfate plus decompression bone in lumbar and lumbosacral spinal fusion: preliminary results in 40 patients.

OBJECTIVE: To compare the efficacy of calcium sulfate pellets plus bone obtained from decompression with fresh autologous iliac crest bone in lumbar and lumbosacral spinal fusion with decompression. DESIGN: A prospective randomized clinical trial. SETTING: Four tertiary care centres in Halifax, NS. PATIENTS: All were consenting, skeletally mature and suffering from degenerative disc disease or spondylolisthesis. The first 40 patients from a single test centre are reported; 32 of these had completed 1-year follow-up. INTERVENTIONS: Posterolateral lumbar or lumbosacral spinal fusion with spinal canal decompression and randomized placement of test material (decompression bone plus an equal volume of calcium sulfate pellets) on one side and control material (autologous posterior iliac crest bone of equal volume to the test material) on the contralateral side, which allowed subjects to act as their own control. OUTCOME MEASURES: Assessment of bone formation by radiographic evaluation at 6 and 12 months after fusion by an independent musculoskeletal radiologist blinded to the placement of test material. RESULTS: At 6 and 12 months after fusion, 78% and 88% of patients, respectively, showed bone formation at the test site that was 75% to 100% of, equal to or more than that at the control site. Increases in bone formation at 6 and 12 months were almost identical at both sites. Smoking status, patient gender or age, instrumentation used and volume of graft used were not predictive of outcome. CONCLUSIONS: Calcium sulfate pellets plus decompression bone provided bone formation equivalent to autologous iliac crest bone in a majority of patients. Calcium sulfate pellets plus decompression bone may provide a viable alternative to autologous iliac crest as a graft material for spinal fusion.

Adult↗
PubMed2002

Vascular leukocyte sequestration in decompression sickness and prophylactic hyperbaric oxygen therapy in rats.

BACKGROUND: Evidence for a causal relationship between decompression sickness (DCS) and leukocyte sequestration was assessed in a rat model based on the effects of interventions which impede cell-to-cell adherence, including hyperbaric oxygen therapy (HBO2). HYPOTHESIS: We hypothesized that leukocyte adhesion to vessels may play a role in DCS. METHODS: Rats were subjected to decompression stress and their ability to ambulate on a rotating drum was assessed to quantify functional neurological deficits. Leukocyte adherence in the brain was measured by a myeloperoxidase (MPO) radioimmunoassay. Interventions included infusion of antibodies to render rats neutropenic or to inhibit leukocyte beta2 integrin adhesion molecules. Tissue gas bubbles were imaged and quantified using a transmission ultrasound camera. RESULTS: Decompressed rats manifested a deficit in their ability to ambulate and a five-fold elevation in concentration of MPO in brain. Neutropenic rats, and those infused with antibody fragments to inhibit leukocyte beta2 integrins, did not exhibit brain MPO elevations, nor a deficit in ambulatory function. HBO2 was used in a prophylactic manner to address its ability to inhibit leukocyte beta2 integrin-mediated adherence without reducing the presence of decompression-induced bubbles. Prophylactic HBO2 prevented cerebral leukocyte sequestration and the performance deficit. CONCLUSIONS: The results implicate beta2 integrin-mediated leukocyte adhesion in neurological deterioration after decompression stress, and offer new insight into the therapeutic action of HBO2. Immunomodulatory approaches, including prophylactic HBO2, may improve the safety of decompression procedures in undersea and space exploration.

Animals↗
PubMed2002

Endoscopic transnasal orbital decompression for thyrotoxic orbitopathy.

OBJECTIVE: To evaluate the efficacy of endoscopic transnasal orbital decompression alone for thyrotoxic orbitopathy. DESIGN: Retrospective review of consecutive procedures. SETTING: Tertiary referral otorhinolaryngology centre. PATIENTS: Twenty-three eyes of 14 patients. INTERVENTION: Endoscopic transnasal orbital decompression. MAIN OUTCOME MEASURES: Proptosis reduction, intra-ocular pressure reduction, exposure keratitis reduction, visual acuity improvement, and complication rate. RESULTS: There were no surgical complications for the 23 orbital decompressions. Proptosis reduction was achieved in 22 (96%) eyes. The mean proptosis reduction was 4.6 mm (median, 5.0 mm; range, 1.0-8.0 mm). The postoperative intra-ocular pressure decreased after surgical decompression in 20 (87%) eyes with a mean reduction of 11 mm Hg (median, 6 mm Hg; range, 1-35 mm Hg). Of the 15 eyes with incomplete closure of the eyelid before the operation, 11 (73%) had complete eyelid closure after surgical decompression. Of the other four eyes that had incomplete closure, the gaps were reduced. The visual acuity was improved for 16 (70%) eyes with a median improvement of 3 Snellen lines (range, 1-8 lines). CONCLUSION: Endoscopic transnasal medio-inferior orbital wall decompression is a safe and adequate treatment for thyrotoxic orbitopathy with proptosis, exposure keratitis, and visual loss.

Adult↗
PubMed2000

[Alteration of free radical generation in pulmonary tissue after quick decompression].

The purpose of this experiment was to evaluate decompression-induced pulmonary injury by means of measurement of ascorbate free radical (Vc-.) alteration in pulmonary tissue of the rats which experienced rapid decompression. 29 male S-D rats were divided into 4 groups: A was executed at 45 min post-decompression; B was control for A; C was executed at 90 min; D was ontrol for C. Group A and group C were to compress up to 0.5 MPa(air) and stay for 60 min, then were decompressed smoothly to normbaric in 1 min. The 0.05 M N-tert-butyl-alpha-phenylnitrone (PBN) was given at 20 min after completion of decompression (groups A and B) or at 65 min (groups C and D). At 25 min after PBN injection the animals were killed by cutting arteria coeliaca, and 0.75 g pulmonary tissues were taken. These tissues were homogenized for electron paramagnetic resonance (EPR) assay. The results demonstrated that the ascorbate free radical (Vc-.) signals were obtained at all samples. The intensity of signals measured in group C rose markedly (P < 0.05) and that in group A was close to control's. So it can be concluded that rapid decompression would increase the generation of free radical in lung.

Animals↗
PubMed2003

Complications induced by decompressive craniectomies after traumatic brain injury.

OBJECTIVE: To find out the optimal approach to decompress externally the severe injured brain and to avoid possible complications caused by external decompression. METHODS: 68 patients who underwent external decompression after traumatic brain injury were admitted into Tianjin Medical University General Hospital for cranioplasty from 1995 to 2001. Complications were retrospectively investigated and analyzed in all patients. The findings were compared between the patients who accepted the decompressive craniectomy in our hospital and in local hospitals. chi(2)-test was employed for statistical analysis and complication evaluation. RESULTS: Large craniectomy definitely caused some side effects to patients. Among various complications, several of them showed significantly high incidence (P<0.05) in patients who underwent the decompressive operation in local hospitals such as shunt-dependent hydrocephalous, subdural fluid collection, and CSF leakage from scalp incision. The rest of the complications had no remarkable difference (P<0.05) between the two groups including dilation or/and migration of lateral ventricle underlying the cranial defect, skin flap concavity, encephalomalacia of the decompressive area, seizure and infection. CONCLUSIONS: To reduce the incidence of iatrogenic side effects, surgical craniectomy should be performed according to the strict indication and standard and any abuse should be avoided.

Adolescent↗
PubMed2003

[Study of platelet membrane glycoprotein expression in mice with decompression sickness].

OBJECTIVE: To investigate the role of expression of platelet membrane glycoprotein CD31, CD61 and CD62p in the pathogenesis of decompression sickness. METHODS: Mice were randomly divided into decompression sickness group and normal control group. The animals in decompression sickness group were exposed to 600 kPa compressed air for 60 minute, then they were rapidly decompressed to normal pressure in one minute. At 60th minute after reducing to normal pressure, the expression of CD31, CD61 and CD62p on platelet membrane in mice was measured by flow cytometry. RESULTS: The mean fluorescence intensity of CD31, CD61 and positive percentage of CD62p on platelet membrane [(18.64 +/- 1.01), (271.06 +/- 24.25), (4.48% +/- 0.43%) respectively] in decompression sickness group were significantly increased compared with normal control group [(16.89 +/- 1.69), (234.09 +/- 15.96), (3.00% +/- 0.66%) respectively] (P < 0.05, P < 0.01). CONCLUSION: Inadequately rapid decompression may induce up regulation of platelet membrane glycoprotein CD31, CD61 and CD62p expression in mice, which may lead to thrombosis.

Animals↗
PubMedDate not supplied

The usefulness of intraoperative needle decompression of the colon during radical gastrectomy--a prospective and randomized trial.

BACKGROUND/AIMS: Intraoperative colonic distension is associated with postoperative ileus, which contributes to delayed hospital discharge. A randomized and prospective study was conducted, to evaluate the usefulness of intraoperative needle decompression of the colon during radical gastrectomy for gastric cancer. METHODOLOGY: Fifty patients that had received subtotal or total gastrectomy for gastric cancer were randomly assigned to either a non-decompression (n=27) or a decompression group (n=23). Prior to the main procedure, the transverse or right colon was pulled up, and a 19-gauge disposable needle connected to suction was introduced to the colon through the taenia site of anterior wall. Gas collected in the colon was aspirated out. The time to the first postoperative passage of flatus or feces was measured precisely to evaluate the restoration of bowel function. Additional measures of outcome were the operation time, the complication rate, and hospital stay. RESULTS: Demographic details, pathologic features, operation time, complication rate and hospital stay were not different between the two groups. A collapsed colon was required for good surgical exposure and easy manipulation. No unexpected complication related to this procedure was found. The first flatus was 6.8 hours sooner in the decompression group than in the non-decompression, though this result was not statistically significant. CONCLUSIONS: This technique is a simple and safe procedure for intraoperative colon decompression during radical gastrectomy.

Colon↗
PubMedDate not supplied

Nasogastric decompression after total gastrectomy.

BACKGROUND/AIMS: Although it is clearly known that there is no need of routine nasogastric decompression after some abdominal operations, we still do not know whether it is necessary for esophageal anastomosis. Traditionally, nasogastric decompression is mandatory after total gastrectomy complemented with esophagojejunostomy. METHODOLOGY: Consecutive 66 patients with gastric cancer who underwent total gastrectomy and esophagojejunostomy were prospectively evaluated. Patients were divided into two groups, those with nasogastric decompression and those without decompression. RESULTS: Postoperative complications were similar among the groups. Vomiting, distention, belching, hiccupping, dysphagia complaints were similar among the groups, but sore throat (100% vs. 22%, p<0.001), nausea (32% vs. 13%, p=0.054), fever (35% vs. 16%, p=0.068) and pulmonary complications (26% vs. 9%. p=0.072) were much more in the nasogastric decompression than the no-tube group. Starting oral feeding and postoperative hospital stay were similar in both groups. CONCLUSIONS: Omission of nasogastric decompression after elective total gastrectomy complemented with esophagojejunostomy did not increase postoperative complications, on the contrary it decreased postoperative fever and pulmonary problems, and improved patient comfort by decreasing sore throat and nausea. Therefore, we do not recommend the routine use of nasogastric tubes after total gastrectomy complemented with esophagojejunostomy.

Adult↗
PubMedDate not supplied

[Growth dynamics and the largest size of gas bubbles emerging in body tissues due to decompression].

Symptoms of decompression sickness (DCS) develop when the total volume of gas bubbles due to decompression reaches the magnitude critical for a body tissue. Number of the bubbles is a function of random nucleation intensity before, during or after decompression and tissue superaeration dynamics, whereas their size is unambiguously dependent on a tissue, decompression phase and bubbling time. A mathematical model of bubble tissue dynamics has been proposed for calculating the dynamics of mathematical expectation of the total gas in tissues and mounting a method for comparative analysis of the maximal DCS probability as a result of implementation of different decompression tables. Unequal intensity of nucleation during spaceflight EVA and its ground simulation w/o spacesuit is the course of inequality of decompression safety of these operations.

Decompression Sickness↗
PubMedDate not supplied

Endoscopic orbital decompression for Graves' ophthalmopathy.

BACKGROUND: Graves' ophthalmopathy generates a volume excess for the orbital cavity, which may produce proptosis, pain, exposure keratitis, diplopia, and optic neuropathy. Endoscopic orbital decompression expands the orbital cavity into the ethmoid cavity and medial maxillary sinus. This retrospective study documents the outcomes after endoscopic orbital decompression for patients with Graves' ophthalmopathy. METHODS: Data collected included demographic information, symptom resolution, complications related to the surgery, reduction in proptosis, subsequent need for eye muscle surgery, and hospital length of stay. Between July 1989 and April 2003, 62 patients were referred for endoscopic orbital decompression (often unilateral). RESULTS: Three patients refused use of their medical records for research purposes. Seventy percent were women; the average age of the study group was 49 years. Preoperatively, 63% of the patients had diplopia and optic neuropathy was noted in 27%. Two patients had a cerebrospinal fluid leak identified and managed during the decompression. No postoperative leaks occurred. Twenty-five percent of patients did not require eye muscle surgery. Forty-eight percent of the patients underwent one procedure to manage diplopia. The average reduction in proptosis was 2.5 mm. Fifty-four percent were managed as an outpatient and 27% underwent a 23-hour observation period. CONCLUSION: This data supports the safety, efficiency, and efficacy of endoscopic orbital decompression for unilateral and bilateral Graves' ophthalmopathy. Eye muscle surgery frequently will be required to manage diplopia after decompression.

Adult↗
PubMed2006

Percutaneous lumbar disc decompression.

Chronic low back pain is a major social, economic, and healthcare issue in the United States. Various techniques are utilized in managing discogenic pain, with or without disc herniation. Percutaneous techniques are rapidly replacing traditional open surgery in operations requiring discectomy, decompression, and fusion. The percutaneous access to the disc was first used in the 1950s to biopsy the disc with needles. Percutaneous access to the disc using endoscopic techniques was developed in the 1970s. Technical advances in the use of intradiscal therapies led to the development of intradiscal electrothermal annuloplasty (IDET), DISC Nucleoplasty, and DeKompressor, along with laser-assisted, endoscopic, and Nucleotome disc decompressions. The indications for percutaneous lumbar disc decompression include low back and lower extremity pain caused by a symptomatic disc. Internal disc disruptions and disc herniations are common causes of low back and/or lower extremity pain which may become chronic, if not diagnosed and treated. Annular tears lead to migration of the nuclear material and deranged internal architecture. In the chronically damaged intervertebral disc, leakage of nuclear material from annular tears can initiate, promote, and continue the inflammatory process and delay or stop recovery of vital remaining intradiscal tissue. The most often stated goal of central nuclear decompression is to lower the pressure in the nucleus and to allow room for the herniated fragment to implode inward. Provocative discography prior to percutaneous lumbar disc decompression is recommended. Percutaneous disc decompression may result in a small number of complications but occasionally, these could be serious.

Decompression, Surgical↗
PubMed2006

[Orbital-bony decompression in patients with dysthyroid orbitopathy--first Croatian experiences].

INTRODUCTION: Dysthyroid orbitopathy or Graves's orbitopathy is an entity made of symptoms and signs found within ocular apparatus, orbit and adnexal tissue in patients with thyroid dysfunction. Orbital pathogenesis is based on organ-specific autoimmune reaction, resulting in extra ocular muscle dysfunction and retro bulbar tissue changes. These changes are characterized by different stages of orbital inflammation, swelling and passive congestion. No infiltrative or inactive stage of the disease is most commonly seen in younger population as mild, orbital inflammation, lid retraction, variable proptosis and retro bulbar discomfort. Infiltrative or active stage of the disease usually affects older people and is characterized by a broad spectrum of clinical symptoms such as moderate or severe orbital inflammation, retro bulbar pain, lid retraction, periocular edema, proptosis with corneal exposure, extra ocular muscle dysfunction, conjunctival and episcleral congestion and optic nerve compression with loss of visual acuity. The current treatment concept for dysthyroid orbitopathy is to achieve euthyroidism with antithyroid drugs, radioiodine and thyroidectomy. Subsequently, for the treatment of dysthyroid orbitopathy immunosuppressive drugs such as corticosteroids, cyclophosphamide, methotrexate, cyclosporine, octreotides, orbital radiotherapy and surgical decompression can be used. Indications for orbital decompression are differentiated as urgent and elective. Current opinion is that only severe proptosis with corneal exposure and damage and compressive optic neuropathy urge orbital bony decompression combined with aggressive medical treatment. Persistent, active orbitopathy, retro bulbar discomfort or pain and disfiguring proptosis are indications for elective orbital bony decompression. Orbital bony decompression is a surgical method based on principle of opening the confined orbital bony space and allowing herniation of orbital fat into paranasal sinuses, thus decreasing orbital pressure. PATIENTS, METHODS AND RESULTS: A series of patients surgically treated for dysthyroid orbitopathy from July 2004 till November 2005, were followed-up. The group included 8 patients previously treated for thyroid dysfunction. Five patients (10 eyes) were operated on by the "swinging eyelid" approach (group 1) and three patients (6 eyes) by "inferomedial approach" (group 2). In group 1 proptosis reduction occurred in all patients, varying from 4 to 6 mm within 6-10 months postoperatively; retrobulbar pain or discomfort decreased in all patients few days after the surgery; and 2 patients still felt numbness in the n. infraorbitalis innervation area at 10 months of follow up. In group 2, all patients had proptosis reduction by 3-4 mm within 6-10 months postoperatively; retro bulbar discomfort disappeared in all patients a few days after the surgery. In this group none of the patients complained of infraorbital numbness 6 months of the surgery. All patients filled out a brief questionnaire before and 4 months after the surgery, ranking their symptoms and complaints. CONCLUSION: Our patient series was rather small and selected, the data obtained are not representative of larger series. Based on these preliminary results and current literature data, we believe that orbital bony decompression is a highly effective, safe and quick procedure, easily adjustable to the surgeon as well as to the patient in achieving optimal results. We also believe that there is a need of better education of our patients considering the disease itself and treatment modalities through patient support groups or better physician-patient-nurse communication.

Adult↗
PubMed1990

A case of decompression sickness at 2,437 meters (8,000 feet).

Among aviators, decompression sickness is a condition that occurs almost exclusively at altitudes above 6,098 m (20,000 ft). Several reports have been published describing the development of decompression sickness after altitude exposures of 3,049 to 4,878 m (10,000-16,000 ft). In most of these cases, the affected individual had a previous history of pain in the involved area due to prior trauma or surgery, or had other risk factors for decompression sickness, such as obesity. Few of these reports have confirmed the presence of decompression sickness by a test of pressure. A case is reported here of multiple joint pains developing after a rapid decompression at 2,439 m (8,000 ft), which improved during descent and rapidly resolved with recompression therapy. There was no prior history of joint pain, trauma, or diving. A brief discussion of decompression sickness is included.

Adult↗
PubMed1984

Health risk factors for the development of decompression sickness among U.S. Navy divers.

The relationship between the health status and physical characteristics of 185 U.S. Navy divers and their risk for experiencing decompression sickness was examined utilizing historical cohort design. Data on multiphasic medical examinations performed on these men between 1972-1978 were obtained. Cases of decompression sickness before and after examination were identified. Divers who did experience decompression sickness either before or after examination had significantly higher measures of skinfold thickness and weight when compared to those who remained free of decompression sickness. Those divers in the highest quartile of each of three significant skinfold thicknesses measured had risks for decompression sickness that were generally 9 to 10 times as great as those calculated for the combined lower 3 quartiles and 5 to 6 times as great as the average crude risk calculated for all Navy divers over the past 5 yr. These findings suggest that obesity may be a contributory factor to the occurrence of decompression sickness.

Body Weight↗
PubMed1982

Changes in blood-brain barrier permeability to drugs in decompressed rats.

A study has been made of changes in permeability of the blood-brain barrier (BBB) to drugs following exposure to compression-decompression. Fifty-five rats were exposed to 6.1 b (abs) air for 90 min and subsequently linearly decompressed to the ambient pressure during a period of 3 min. Thirty-five rats serving as controls were kept at the ambient pressure. Catalepsy, which is mediated through the striatal dopamine receptors, was used as a behavioral indicator for the penetration of drugs into the brain. A comparison was made between drugs that normally pass the BBB (atropine, 10 mg/kg; haloperidol, 2 mg/kg) and drugs that do not readily pass the BBB as a rule (methylatropine, 10 mg/kg; domperidone, 10-20 mg/kg). Evans blue, injected intravenously, was used for the visualization of possible changes in the BBB permeability. It was found that methylatropine significantly prevented haloperidol-induced catalepsy in decompressed rats, in comparison with control rats. However, this prevention was not so intense as that found after injection of a similar dose of atropine. Domperidone induced a weak catalepsy in decompressed rats, but failed to induce any catalepsy in control rats. Gross and fluorescence-microscopic examination revealed an increased penetration of Evans blue into the brains of the decompressed rats. It is concluded that compression-decompression exposure can induce a limited but significant breakage of the BBB, leading to an increase in the central effects of the drugs that normally display poor penetration of the BBB. The measurement of behavioral changes provided a new and relevant technique for studying the changes of BBB permeability to drugs.

Animals↗