Simultaneous Ashworth measurements and electromyographic recordings in tetraplegic patients

OBJECTIVE

A recent prevalence study of 353 spinal cord injured (SCI) individuals in the greater Stockholm area showed problematic spasticity in 30% of this population. To treat spasticity, the evaluation becomes crucial. The modified Ashworth scale (MAS) is the clinically most-used scale to grade degree of spasticity. This study evaluated whether the MAS correlated with electromyographic (EMG) recordings of muscle activity.

STUDY DESIGN

This cross-sectional study was performed at an outpatient clinic that has the responsibility to do a standardized, yearly follow-up of all SCI patients in the greater Stockholm area. Thirty-eight SCI individuals met the inclusion criteria; 15 of the 38 were randomly selected for the study. They were all motor-complete tetraplegic men; mean age was 33 years and mean time since injury was 9 years. Spasticity evaluation was performed by flexing and extending the knees during simultaneous EMG recordings and MAS assessment of the thigh muscle activity.

RESULTS

Eighty percent of the individual EMG recordings correlated significantly with the corresponding Ashworth measurements. The spastic resistance, as measured both clinically and electromyographically, was stronger and lasted longer during extension than flexion movements. Spearman coefficients for correlation of quantitative spasticity measures with MAS grades were calculated. EMG and clinical measures of spasticity were more closely correlated for flexion movements. Among EMG parameters, duration of movement-associated electrical activity invariably correlated significantly with the MAS grades (p < .05). Furthermore, Ashworth measurements of movement-associated spasticity showed a positive correlation with the EMG parameters mean, peak, and start to peak of electrical activity. Each increasing grade on the MAS corresponded to increasing myoelectric activity levels for each movement.

CONCLUSION

EMG parameters were significantly positively correlated with simultaneous MAS measurements of the spastic muscle contraction. The Ashworth scale may therefore accurately reflect the movement-provoked spasticity in motor-complete tetraplegic patients.

Induction of beta-family chemokines mRNA in human embryonic astrocytes by inflammatory cytokines and measles virus protein

The cellular infiltration found during CNS inflammation consists of monocytes and activated T cells, suggesting the presence of cell-specific chemotactic signals during inflammatory responses. Astrocyte chemokine expression might contribute to site-specific leukocyte infiltration within the CNS. To investigate the factors that regulate astrocyte chemokine expression, we examined the ability of human fetal astrocytes to induce beta-family chemokine mRNA. Astrocyte-derived monocyte chemoattractant protein-1 (MCP-1), RANTES, macrophage inflammatory protein-1alpha (MIP-1alpha), and MIP-1beta mRNA were easily induced by lipopolysaccharide and/or the proinflammatory cytokines (IFN-gamma and/or TNF-alpha), respectively. Addition of both IFN-gamma and TNF-alpha together did not lead to an additive effect but resulted in the inhibition of MCP-1 and MIP-1beta mRNA expression, indicating that interaction between chemokines and cytokines may play a key role in regulating the local immune response of resident and infiltrating cells at the site of lesion. Interestingly, ultraviolet light-inactivated measles virus, but not cytomegalovirus, strongly induced expression of MCP-1, RANTES, MIP-1alpha, and MIP-1beta mRNA in human embryonic astrocytes, especially MCP-1 and MIP-1beta. An association occurs between the beta-family chemokine expression in astrocytes and inflammatory factors/virus, suggesting a possible role for beta-family chemokines in the pathogenesis of CNS inflammatory disease.

Regional distribution of nicotinic receptors during prenatal development of human brain and spinal cord

The development of nicotinic acetylcholine receptors (nAChRs) in brains from human fetuses of 4-12 weeks gestational age was studied. The expression of nAChR subunit mRNAs was analyzed using reverse transcriptase-polymerase chain reaction. Expression of alpha 3, alpha 4, alpha 5, alpha 7, beta 2, beta 3 and beta 4 mRNA were all detected in the prenatal spinal cord, medulla oblongata, pons, cerebellum, mesencephalon, subcortical forebrain and cortex during first trimester development. Relative quantification of mRNA showed that the highest levels for alpha 3, alpha 4 and alpha 7 were expressed in the spinal cord, alpha 5 was most abundant in the cortex and beta 3 was highest in the cerebellum. beta 4 seemed to be equally distributed in all regions whereas beta 2 was high in the cortex and cerebellum. A comparison of expression of nAChR subunit mRNAs in the cortex and cerebellum of prenatal and aged (54-81 years) brain showed that mRNA levels for alpha 4, alpha 5, alpha 7, beta 2 and beta 4 were significantly higher in the prenatal cortex and cerebellum than in aged brain, whereas the level of alpha 3 transcript was similar, and beta 3 significantly higher in aged cortex. Specific binding of [3H]-epibatidine to prenatal brain membranes was detected as early as 4-5 weeks of gestation in the spinal cord, medulla oblongata, pons and subcortical forebrain. A positive correlation between gestational age and [3H]-epibatidine and [3H]-cytisine binding was found in several brain regions. The highest specific binding of [3H]-epibatidine and [3H]-cytisine was detected in the spinal cord, pons and medulla oblongata and the lowest in the cortex. Saturation analysis of [3H]-cytisine binding in both prenatal and aged brain were best fit by a model for a single site, whereas binding data for [3H]-epibatidine revealed two classes of binding sites. The early presence of nAChR proteins and gene transcripts shown in the present study suggests an important role for nAChRs in modulating dendritic outgrowth, establishment of neuronal connections and synaptogenesis during development.

Interactions between human embryonic forebrain cells and the cytokines interferon-gamma and interleukin-4

In the present study we investigated the capacity of human first trimester forebrain cells at different gestational ages to produce IFN-gamma and IL-4. We also studied the effects of IFN-gamma on their proliferation, survival and expression of MHC antigens. IFN-gamma but not IL-4 was spontaneously produced after 24 h cultures. Furthermore, IFN-gamma exhibited anti-proliferative effects and induced MHC expression on these cells. However, the IFN-gamma exposed cultures showed significantly higher cell survival compared to un-exposed cultures. Co-culture with IL-4 blocked the IFN-gamma production and reversed its anti-proliferative effects. These interactions suggest important roles for cytokines in the survival, proliferation and differentiation of human embryonic and fetal forebrain cells.

Human embryonic spinal cord grafts in adult rat spinal cord cavities: survival, growth, and interactions with the host

The ability of solid pieces of transplanted human embryonic spinal cord to survive, grow, and integrate with adult rat host spinal cord tissue was investigated. Unilateral cavities were surgically created at vertebral level T12-T13 in 10 athymic nude rats and 5 regular Sprague-Dawley rats. Seven of the athymic rats acutely received a human spinal cord graft, while the remaining 8 rats served as controls, with cavities alone. After 6 months the morphological outcome was evaluated with cresyl violet and with immunohistochemistry using antibodies toward human-specific neurofilament (hNF), human-specific Thy-1 (Thy-1), neurofilament, glial fibrillary acidic protein, serotonin (5-HT), and tyrosine hydroxylase (TH). The in situ morphology of the human embryonic spinal cord was also investigated and compared with grafts that were six months older. Solid human embryonic spinal cord grafts showed a 100% survival rate, grew to fill the volume of the cavity in a noninvasive manner, and expressed human specific antigens 6 months postgrafting. Thy-1 immunoreactivity (IR) was demonstrated up to 8 mm rostral to the graft suggestive of graft-derived fiber outgrowth. hNF-IR fibers and 5-HT- and TH-IR fibers traversed the graft-host border for a few hundred micrometers, respectively. Finally, our findings suggest that grafted solid pieces of human embryonic spinal cord minimize cystic deformations seen in the adult rat spinal cord with a unilateral cavity.

Human dorsal root ganglion neurons from embryonic donors extend axons into the host rat spinal cord along laminin-rich peripheral surroundings of the dorsal root transitional zone

Following dorsal root crush, the lesioned axons regenerate in the peripheral compartment of the dorsal root, but stop at the boundary between the peripheral and the central nervous system, the dorsal root transitional zone. We have previously shown that fibres from human fetal dorsal root ganglia grafted to adult rat hosts are able to grow into the spinal cord, but were not able to specify the route taken by the ingrowing fibres. In this study we have challenged the dorsal root transitional zone astrocyte boundary with human dorsal root ganglion transplants from 5-8-week-old embryos. By tracing immunolabelled human fibres in serial sections, we found that fibres consistently grow around the dorsal root transitional zone astrocytes in laminin-rich peripheral surroundings, and extend into the host rat spinal cord along blood vessels, either into deep or superficial laminae of the dorsal horn, or into the dorsal funiculus. Human fibres that did not have access to blood vessels grew on the spinal cord surface. These findings indicate, that in spite of a substantial growth capacity by axons from human embryonic dorsal root ganglion cells as well as their tolerance to non-permissive factors in the mature mammalian CNS, these axons are still sensitive to the repellent effects of astrocytes of the mature dorsal root transitional zone. Furthermore, this axonal ingrowth is consistently associated with laminin-expressing structures until the axons reach the host spinal cord.

Analysis of NMDA receptors in the human spinal cord

NMDA receptors in postmortem human spinal cord were analyzed using [3H]MK-801 ligand binding and immunoblotting with NMDA receptor subunit-specific antibodies. The average KD for [3H]MK-801 binding was 1.77 nM with a Bmax of 0.103 pmol/mg. The EC50 for stimulation of -3H-MK-801 binding with L-glutamate was 0.34 microM. None of these parameters were affected by postmortem intervals up to 72 h. Immunoblotting of native NMDA receptors showed that NR1, NR2A, NR2C, and NR2D subunits could all be found in the human spinal cord of which NR1 was preferentially located to the dorsal half. Immunoprecipitation of solubilized receptors revealed that NR1, NR2C, and NR2D subunits coprecipitated with the NR2A subunit, indicating that native human spinal cord NMDA receptors are heteroligimeric receptors assembled by at least three different receptor subunits. These results provide a basis for the development of drugs selectively aimed at spinal cord NMDA receptors for the future treatment of spinal cord disorders.

Sexuality in women with traumatic spinal cord injury

BACKGROUND

Sexuality in spinal cord injured women has largely been neglected. One reason may be the male dominance amongst traumatically spinal cord injured individuals. The purpose of this study is to elucidate sexual issues in women with spinal cord injuries.

METHODS

Survey of near-total prevalence population in the greater Stockholm area. Structured interview, based on a standardized questionnaire. Self-rating scales for evaluation of the importance of sexual activity before and after injury and for defining and rating the medical problem most significantly interfering with sexual activity. Marital status and/or partnership pre- and post-injury and information on sexual matters provided after injury were evaluated in detail. Out of a total 65 women, 62 participated in the study.

RESULT

Women with complete and incomplete cervical lesions rated the importance of sexual activity significantly lower after, as compared to before, spinal cord injury. No significant differences were found in women with lower-level lesions. Urinary leakage, spasticity and positioning problems were the medical problems most significantly interfering with partner-related sexual activity. Only six women had received information on sexual matters before discharge from hospital. None of the partners had received such information.

CONCLUSION

The women's neurological status affect their ability to adapt sexually after injury. Medical problems commonly interfere with sexuality and should be identified and treated. No adverse impact of spinal cord injury on marital status could be confirmed. Sexual counseling has yet to become an integral part of rehabilitation.

Obliteration of a posttraumatic spinal cord cyst with solid human embryonic spinal cord grafts: first clinical attempt

Cystic lesions of the spinal cord (syringomyelia) may occur after spinal cord injury. Posttraumatic syringomyelia may result in a myelopathy causing symptoms of sensory and motor loss, as well as worsening spasticity, pain, hyperhidrosis, and autonomic dysreflexia. Shunting of the cyst cavity along with untethering of the scarred spinal cord is widely accepted as the treatment of choice. However, the long-term stabilization of the progressive myelopathy caused by a posttraumatic cyst is suboptimal because of arachnoidal rescarring, shunt tube blockage, and cyst reexpansion. A new neurosurgical strategy to overcome the complication of cyst reexpansion was designed. Experimental studies have shown the successful use of embryonic spinal cord grafts, including human grafts, to obliterate induced spinal cord cavities in rats. The authors report the first use of solid human embryonic spinal cord grafts to successfully obliterate 6 cm of a large cyst cavity in a patient becoming myelopathic from a posttraumatic cyst. The grafts are well visualized by MRI to the 7-month postoperative follow-up and cyst obliteration is seen in the region where the grafts were placed.

Morphological characterization of the evolving rat spinal cord injury after photochemically induced ischemia

We have characterized the evolving morphological changes in the adult rat spinal cord following photochemically induced spinal cord ischemia. In cresyl violet-stained sections, disintegration of the tissue at the epicenter was evident at 6 h. This was preceded at 1 h post ischemia by an albumin immunoreactivity. The albumin immunoreactivity was increased at 6 and even more so at 24 h post ischemia. At 72 h post ischemia the albumin immunoreactivity was decreased. The size of the lesion was established by 3 days after the onset of ischemia. During the 1st week post ischemia, neurofilament (NF) immunohistochemistry showed swollen axons adjacent to the injured tissue. From 2 weeks post ischemia an increasing number of regrowing NF-immunoreactive axons could be seen in the center of the necrotic cavity. At 3 weeks after ischemia, a developing gliosis was observed around and rostral to the lesion cavity, as evidenced by increased glial fibrillary acidic protein (GFAP) immunoreactivity. The gliosis became more pronounced until 6 weeks post ischemia, at which time enlarged GFAP-immunoreactive cells could be seen in the remaining viable tissue bordering the necrotic areas. In this study we show that several traits in the development of a spinal cord lesion after photochemically induced ischemia are similar to those described previously after traumatic spinal cord lesions.

Clip compression injury in the spinal cord: a correlative study of neurological and morphological alterations

Rats subjected to experimental spinal cord compression of different degrees induced by aneurysm clips were neurologically tested 3 and 5 weeks postinjury. The development of spinal cord tissue destruction over time was similar to what has been described for other experimental spinal cord injuries with characteristics such as early edema, axonal swelling, and later necrosis. Three weeks after injury a reactive gliosis was found at the injury epicenter and regenerating axons could be identified in the otherwise necrotic cavity. The extent of degeneration was highly correlated with the closing force of the aneurysm clip. The results of a number of neurological tests were correlated to the degree of clip-induced compression, to lesion volume, and to the remaining area of white matter at the epicenter. The neurological tests with the highest correlation to morphological descriptors were beam walk (r(s) = 0.89-0.95) and motor performance score (r(s) = 0.88-0.92). We conclude that the motor performance score, previously validated for photochemically induced ischemic spinal cord injuries, is equally suitable for clip compression injuries as a fast and reliable neurological test paradigm.

No protective effect of the NMDA antagonist memantine in experimental spinal cord injuries

We have investigated the effect of memantine, a clinically used NMDA receptor antagonist, in two experimental animals models of spinal cord injury. The lesions were laser-induced photothrombosis to induce focal spinal cord ischemia and clip compression to mimic traumatic spinal cord injury. Pre- or posttreatment of rats with a dose of memantine (20 mg/kg ip) previously shown to be neuroprotective in cerebral ischemia, failed to affect both the neurological and morphological outcome of ischemic spinal cord injury. Likewise, memantine had no effects on neurological and morphological outcome after experimental traumatic injury. In view of the regional heterogeneity of NMDA receptors, the affinity of memantine for spinal cord NMDA receptors was also determined by studying displacement of [3H] (+)-5-methyl-10,11-dihydro-5-H-dibenzo[a,d]cyclohepten-5-10-imine (MK-801) to rat and human spinal cord homogenates. We found that memantine had an affinity for NMDA receptors in the spinal cord (Ki = 0.58 microM) that was significantly lower compared to that of the cerebral cortex (Ki = 0.23 microM) and that the affinity for NMDA receptors in human spinal cord was even lower. We conclude that in view of available data, memantine should not be chosen for clinical studies on neuroprotection in spinal cord injuries and that the lack of protective effect is most likely due to insufficient affinity of memantine for spinal cord NMDA receptors.

Tissue distribution of transplanted fetal liver cells in the human fetal recipient

OBJECTIVE

Our purpose was to study the tissue distribution and concentrations of transplanted fetal liver cells in the human fetus.

STUDY DESIGN

Radiolabeled indium 111 fetal liver cells were injected in vivo under ultrasonographic guidance into 10 normal fetuses (13 to 17 weeks of gestation) before a prostaglandin abortion. Six fetuses were injected intraperitoneally and four intracardially. Another two fetuses serving as controls were injected with indium-labeled maternal plasma. The fetuses were all alive, at least until 6 hours before expulsion. After expulsion the fetuses were dissected, and radioactivity was measured in various fetal tissues. Results for each tissue were expressed as percentages of the total injected dose.

RESULTS

Significantly greater uptake of fetal liver cells in the liver, spleen, thymus, kidney, lung, and placenta was obtained with intracardiac than with intraperitoneal injection. Skeletal uptake did not differ in relation to mode of administration. With intracardiac injection uptake was greater in such parenchymal organs as the liver, spleen, and thymus (4.9%, 4.0%, and 3.9%, respectively). Uptake in the rib, clavicle, humerus, and sternum was 2.7%, 1.8%, 2.1%, and 1.1%, respectively. Placental uptake was 0.1%. The intracardiac route yielded a higher concentration of cells in different fetal organs than did injection of only radiolabeled maternal plasma, suggesting an active uptake of cells in different fetal hematopoietic organs.

CONCLUSION

The mode of administration of fetal liver cells seems to be a major determinant of donor cell concentration in the transplanted human fetus and may be a significant determinant of the rate of successful engraftment.

First trimester development of the human nigrostriatal dopamine system

The aim of the present study was to characterize the morphological and neurochemical differentiation of mesencephalic dopaminergic neurons in human embryos, derived from elective first trimester abortions. Embryonic brain tissue was taken for analysis of tyrosine hydroxylase (TH) by immunohistochemistry and Western blot, and for analysis of endogenous dopamine (A) content using HPLC-ED. TH expression was first detected at 3.5 weeks of gestational age (Carnegie stage 11) by immunohistochemical staining of the primordial sympathetic trunk along both sides of the neural tube. In sagittal sections of the intact 4.5-week-old embryo, a small, distinct population of rounded, densely packed TH-immunoreactive perikarya with short primary processes was seen in the midbrain. During the latter half of the first trimester, the number of TH-stained cells as well as the length and number of axonal processes projecting toward and into the developing neostriatum increased rapidly. At the end of the first trimester, varicose fibers could be detected in the striatal anlage. In order to verify that TH was the antigen recognized by the antibodies used for immunohistochemistry on human tissue specimens, mesencephalic tissue of 5-10 weeks gestation was analyzed by Western blot technique. A single, homogeneous band with the apparent molecular weight of approximately 60 kDa was clearly detected at 5 weeks of age. The amount of TH/mg total protein increased at least 10-fold between 5-10 weeks of gestation. For comparison, the mesencephalon and the forebrain/basal ganglia were analyzed for endogenous DA content using HPLC-ED. DA was first detected at 5.5 weeks of gestational age in both mid- and forebrain, and DA levels were found to increase exponentially from 7 to 7.5 weeks of age, reaching 4-5.5 ng DA/mesencephalon and 50-75 ng DA/g caudate nucleus-putamen anlage at the end of the first trimester. Together, morphological and biochemical data presented here constitute evidence for a very early appearance, migration, and differentiation as well as functional development of human mesencephalic dopaminergic neurons and their projections into target areas during the first trimester.

Lack of evidence of permanent engraftment after in utero fetal stem cell transplantation in congenital hemoglobinopathies

The use of fetal hematopoietic stem cells for in utero transplantation to create permanent hematochimerism represents a new concept in fetal therapy. In one fetus with alpha-thalassemia, one with sickle cell anemia, and one with beta-thalassemia, we have transplanted fetal liver cells obtained from legal abortions in gestational weeks 6-11. The fetus with alpha-thalassemia was transplanted twice during pregnancy, in the 15th (20.4 x 10(8) cells/kg) and in the 31st weeks of gestation (1.2 x 10(8) cells/kg), and is now two years of age. One fetus with sickle cell anemia received its transplant in the 13th week of gestation (16.7 x 10(8) cells/kg), and is now one year old. The fetus with beta-thalassemia was transplanted in 18th week (8.6 x 10(8) cells/kg), and is now three months old. Engraftment was evaluated by chromosomal analysis (sex chromosomes), red cell phenotyping, HLA class I and II typing, and PCR (polymerase chain reaction) for Y chromosome-specific sequences and DNA polymorphisms in cord and peripheral blood. The children with alpha- and beta-thalassemia underwent bone marrow aspirations at 3 and 7 months of age, respectively. In neither of these cases were we able to detect convincing evidence of stem cell engraftment. Thus, the administration of fetal stem cells to fetal recipients after the 12th week of gestation did not result in permanent hematochimerism. It remains to be determined whether the engraftment process can be promoted by earlier transplantations and/or higher cell doses.

The Stockholm spinal cord injury study: 4. Psychosocial and financial issues of the Swedish annual level-of-living survey in SCI subjects and controls

In a series of articles from the Stockholm Spinal Cord Injury Study (SSCIS), the health status of a near-total regional SCI population comprising 353 subjects has been investigated. The present study describes the psycho-social and financial consequences of SCI in this group. It is based on a level-of-living survey that has been used annually on 8000-14,000 Swedes since 1974. The health-focused version of this survey was used for data collection in the subset of 326 subjects in the SSCIS that were residents of the Greater Stockholm area. The normative material consisted of 1978 interviews of residents of the same area, provided by the Swedish Bureau of Statistics. The results show that SCI subjects, although provided with basic material commodities up to par with the general population, have less financial reserves and more frequently express worry about their finances. Less than half of the subjects are gainfully employed, when part-time jobs are also included. Social activities are more restricted, and more centered on the core social network. Several items in the survey point to a preoccupation with personal rather than public matters. We feel that these factors, at least to some degree, are consequential to separation from the workplace, with resulting disadvantageous financial and social effects. Intensified vocational rehabilitation efforts might thus be justified from both an economic and a psycho-social point of view.

Motor performance score: a new algorithm for accurate behavioral testing of spinal cord injury in rats

To evaluate the usefulness of standard neurological tests in predictin g the neurological outcome after photochemically induced spinal cord lesions in rats, we inflicted injuries of different severity to adult female rats. The behavior of the rats was followed for 6 weeks and the results of the behavioral tests were correlated with morphological indicators of tissue destruction at the end of this period. We found many behavioral tests to be highly correlated with the loss of tissue, whereas some tests were inaccurate in correlating with degree of tissue destruction. Motor score, beam walk, and righting reflect were all highly correlated with the volume of the lesion as well as the depth of the lesion cavity at its epicenter. We propose a protocol for neurological evaluation of this type of spinal cord injury consisting of six individual tests, hierarchally organized such that injured rats can be divided into 11 groups ofn eurological deficit, scored from 10 to 0. This so-called motor performance score is fast and easy to perform and shows high correlation with the lesion volume, and is thus suitable for neurological evaluation of photochemically induced spnial cord injury.

The Stockholm Spinal Cord Injury Study. 3. Health-related issues of the Swedish annual level-of-living survey in SCI subjects and controls

In previous articles on the Stockholm Spinal Cord Injury Study (SSCIS), we have reported the frequent occurrence of medical problems in a near-total regional SCI population comprising 353 subject. This present study further investigates health-related issues in this SCI population, by a level-of-living survey that has been used annually on 8000-14,000 Swedes since 1974. The health-focused version of this survey was used for data collection in those 326 subjects in the SSCIS who were residents of the Greater Stockholm area. Subjects of the SSCIS living on the island of Gotland were excluded because they represented a sociodemographically different (rural) population. The normative material consisted of 1978 interviews of residents of the Greater Stockholm area, provided by the Swedish Bureau of Statistics. Results show a higher utilisation of health care resources among SCI subjects, shown by higher rates of long-term sick leave and sick pension, and more treatment as inpatients, emergency room attendees, and outpatients. Pain, bladder problems, and psychological symptoms are more commonly reported by SCI subjects. Medications such as antibiotics, analgesics, sedatives, hypnotics and laxatives are used more frequently in the SCI group. In contrast, no statistically significant differences were found as regards reported prevalence of diseases other than SCI, including diabetes, hypertension and cardiac disease. The results thus verify the impression from our previous studies of a clearly increased morbidity among these SCI subjects. The increased morbidity seems to be accounted for by the SCI itself, or conditions directly caused by it.

The Stockholm Spinal Cord Injury Study: 2. Associations between clinical patient characteristics and post-acute medical problems

The Stockholm Spinal Cord Injury Study (SSCIS) is an extensive evaluation of a sample of 353 subjects with traumatic SCI, constituting 93% of the known regional prevalence population with this diagnosis. In a previous analysis of this group, symptoms such as pain, incontinence, sexual dysfunction and neurological deterioration, as well as secondary complications, such as decubitus ulcers, urinary tract infections, spinal deformity and fractures, were found to be common. In the present report, we investigate associations between a few commonly used patient characteristics, ie gender, age at injury, duration of injury and extent of neurological compromise, and the occurrence of such problems, to assess differences in vulnerability in SCI subgroups. Results generally indicate an increased vulnerability in subjects with extensive neurological deficits, as well as a cumulation of complications with the increasing duration of injury. However, some exceptions are found, possibly indicating differences in temporal patterns of the occurrence of various complications, as well as certain gender-, age-, and lesion-associated variations in vulnerability. Symptoms directly related to the spinal cord lesion, eg neurogenic pain and neurological deterioration, seem to present rather soon post-injury. Males are more prone to experience excessive spasticity and sexual problems. Females experience more fractures and spinal deformity. Younger age at injury is associated with more spinal deformity but less severe pain problems. Higher age at injury is not found to be associated with more medical problems, with the exception of neurogenic pain, among post-acute, post-discharge survivors. The latter finding does not, however, preclude more such problems in the acute stage, since the present study neither addresses the pre-discharge period, nor includes information about mortality. Finally, the ASIA/IMSOP Impairment Scale Grade E-rated subjects were found to report problems to an extent that underlines the restricted sensorimotor sense in which this rating reflects recovery.

In vivo studies on NMDA-evoked release of amino acids in the rat spinal cord

In the present study, spontaneous and evoked release of selected amino acids in the rat spinal cord was studied using in vivo microdialysis. Perfusion of the microdialysis probe with 100 K+ evoked a 2-4-fold increase in release of the putative neurotransmitters aspartate, glutamate and taurine while glutamine was decreased. K(+)-evoked release of glutamate was almost completely Ca(2+)-dependent while that of aspartate was partially Ca(2+)-dependent. Taurine release was not affected by substituting Ca2+ with Co2+. Perfusion with 5 mM N-methyl-D-aspartate (NMDA) evoked 3-9-fold release of glutamate, glycine and taurine and a small increase in extracellular beta-alanine. No significant changes in glutamine and serine were found. 5 mM of the competitive NMDA antagonist 3-((+/-)-2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) reduced NMDA-evoked release of glutamate and taurine by approx. 50%. 5 mM 3-amino-1-hydroxypyrrolid-2-one (HA-966), an agonist at the glycine site of the NMDA receptor with very low efficacy, completely inhibited NMDA-evoked release of taurine and reduced the levels of released glutamate below baseline, similar to the effect of 1 mM CPP alone. The present results show that in situations of excessive release of excitatory amino acids such as spinal ischemia and trauma. NMDA receptor-evoked release of glutamate may amplify the deleterious process and spread the damage.

The Stockholm spinal cord injury study: 1. Medical problems in a regional SCI population

Out of a regional traumatic spinal cord injury population consisting of 379 individuals, 353 (93.1%) participated in the present study. Subjects were individually interviewed using semi-structured protocols. In addition, previous medical records were available for over 96% of subjects, and were used in all these cases to minimise recall bias. Cause of injury, prevalence of present medical symptoms and occurrence of medical complications in the post-acute, post-discharge phase were recorded. Neurological classification was verified by physical examination according to ASIA/IMSOP standards. Many subjects had experienced complications since discharge from initial hospitalisation, especially urinary tract infections, decubitus ulcers, urolithiasis, and neurological deterioration. Prevalence of medical symptoms was also high. More than 41% of subjects with spastic paralysis reported excessive spasticity to be associated with additional functional impairment and/or pain. Almost two-thirds of subjects reported significant pain, with a predominance of neurogenic-type pain. Bladder and bowel dysfunction were each rated by nearly 41% of subjects as a moderate to severe life problem. As expected, sexual dysfunction was also commonly reported. Prevalence of reported symptoms by general systems review was high, particularly fatigue, constipation, ankle oedema, joint and muscle problems, and disturbed sleep. However, lack of adequate normative data precludes comparison with the general population. The frequent occurrence of reported medical problems and complications support advocacy of comprehensive, life-long care for SCI patients. The commonly reported problems of neurogenic pain and neurological deterioration, in particular, require more attention, as these symptoms are not seldom ominous, either by virtue of their impact on quality of life, or because of underlying pathology.

Screening of fetal stem cells for infection and cytogenetic abnormalities

Fetal stem cell transplantation may rely on material from therapeutic abortions. It is essential that the stem cell transplant does not transmit any microorganisms that may affect the fetus and that genetically abnormal cells are avoided. To evaluate such contamination, human fetal stem cells collected February 1992 - December 1993 were analyzed for bacterial and fungal growth, and the placentas were karyotyped. Four samples of 70 were positive for different pathogens. Serological screening of 43 women during this period resulted in five seroconversions and revealed one carrier of anti-HCV. Karyotyping revealed two abnormal findings out of 72 samples. Thus, the concept of using material from therapeutic abortions is safe.

Neuronal development in embryonic brain tissue derived from schizophrenic women and grafted to animal hosts

The distribution of schizophrenia in families supports the hypothesis of heritable risk factors in schizophrenia, but there is as yet no identification of an inherited neurobiological defect. Human embryonic brain tissue fragments, derived from first trimester abortions, can be transplanted into rat hosts, where they continue neuronal development and are accessible for neurobiological investigation. Hippocampal transplants derived from three schizophrenic women and a larger series of normal women have been studied. If there are heritable neuronal defects associated with schizophrenia, a proportion of the transplants from schizophrenic women would be expected to carry these defects. The transplants from the first two schizophrenic women showed profound abnormalities in survival and growth, compared to the series of transplants from normal women. The transplants from the third schizophrenic woman showed normal growth and development, as well as typical histological and electrophysiological features. The data must be regarded as preliminary, because of the small number of subjects that have been studied. However, they are consistent with the transmission of a defect in neuronal development to some of the offspring of schizophrenic women, a possibility consistent with other studies of the pathogenesis of schizophrenia. The mechanism of the defect in development remains to be identified.

Decreased GABA immunoreactivity in spinal cord dorsal horn neurons after transient spinal cord ischemia in the rat

The number of GABA-like immunoreactive (LI) cells in lamina I-III of the rat spinal cord was significantly decreased bilaterally 48-72 h after photochemical induction of transient spinal cord ischemia compared to sham-operated controls. No significant changes in the number of GABA-LI cells were observed at cervical level. The number of GABA-LI cells was restored 2 weeks after ischemia. These data, together with recent behavioral and electrophysiological findings, suggest that decreased intraneuronal GABA levels after spinal cord ischemia may underlie the development of the temporary pain-like response to innocuous mechanical stimuli (allodynia) in rats after transient spinal cord ischemia.

NBQX, a competitive non-NMDA receptor antagonist, reduces degeneration due to focal spinal cord ischemia

We have used the laser-induced photochemical thrombosis model in adult rats to evaluate the significance of the non-N-methyl-D-aspartate (non-NMDA) subtype of glutamate receptors in situations of focal spinal cord ischemia. The animals were pretreated with the selective non-NMDA antagonist 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)-quinoxaline (NBQX) or, for comparison, the NMDA antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5-10-imine (MK-801). Neurological function was quantified using evaluations of motor score and inclined plane. The MK-801-treated rats had higher motor scores during the 3-week observation period while NBQX-treated rats only performed significantly better at 1 week. Both treatments caused significantly better performance in the inclined plane test. NBQX and MK-801 reduced the volume of necrosis by approximately 47% at 3 weeks postlesion. We conclude that blockade of both NMDA and non-NMDA subtypes of glutamate receptors reduces ischemic necrosis, possibly by preventing excessive stimulation of these receptors by released excitatory amino acids in the lesion area.