[Spinal cord tethering in myelomeningocele and lipomeningocele patients: the second operation]. / Reanclaje medular en pacientes con mielomeningocele y lipomeningocele: la segunda operación.

BACKGROUND: Spinal cord rethetering can occur after the primary surgical repair of myelomeningoceles (MMC) and lipomeningoceles (LMC) and produce devastating physical and psychological consequences. The inadvertent introduction of skin elements at the time of the initial surgery can lead to the growth of intraspinal epidermoid or dermoid cysts. OBJECTIVES: To review the incidence of spinal cord tethering following surgery for open and occult spinal dysraphism and to analyze factors that might influence the appearance of this complication. We also aimed to search technical measures at the time of the primary operation that might prevent the occurrence of symptomatic cord retethering. MATERIAL AND METHODS: We reviewed the medical records of patients submitted to surgical repair of MMC (n=162) or occult spinal dysraphism (n= 54) during the period 1975-2005 who developed symptomatic tethered cord syndrome. RESULTS: Eleven of 162 (6.79%) patients with MMC and 2 of 54 (3.7%) with LMC developed clinical symptoms and signs of spinal cord tethering after intervals ranging from 2 to 37 years after the initial surgical repair of their back lesions. Indications for surgical re-exploration were based mainly on clinical grounds. Postoperative fibrosis was a constant finding in all instances. Other surgical findings included inclusion tumors of cutaneous origin (n=3), lumbar canal stenosis (n= 2), foreign body reactions (n= 2), residual lipoma (n= 1), and a tight hyalinized filum (n=1). Interestingly, 3 of 162 (or 1.85%) myelomeningoceles were found to harbor an intradural epidermoid tumor at the time of spinal cord dethetering, accounting for an incidence of cutaneous inclusion tumors of 27% in cases of post- MMC repair tethering. After a mean follow-up time of 5.5 years, eight patients were improved, two were unchanged and one was worsened. CONCLUSIONS: Neurological deterioration is not a necessary consequence of the natural history of patients with MMC or LMC. Early or late clinical deterioration can be due to spinal cord re-tethering and deserves timely investigation and surgical exploration. Results of surgical intervention were rewarding as 92% of the patients showed improvement or stabilization in their otherwise deteriorating condition. We also report two infrequent causes of spinal cord deterioration: lumbar canal stenosis and intense foreign-body reactions to implanted materials.

Reanclaje medular en pacientes con mielomeningocele y lipomeningocele: la segunda operación / Spinal cord tethering in myelomeningocele and lipomeningocele patients: the second operation

Antecedentes. La médula espinal puede fijarse tras la reparación inicial en pacientes operados demielomeningocele (MMC) y lipomeningocele (LMC), produciendo graves lesiones físicas y psicológicas. Asimismo, la introducción accidental de restos cutáneos durante la reparación de estas lesiones puede dar lugar al desarrollo de tumores intraespinales de estirpe cutánea. Objetivos. Averiguar la incidencia del anclaje medular tras la cirugía de MMC y LMC y analizar los factores que puedan explicar su aparición. También, investigamos las maniobras técnicas durante la operación primaria susceptibles de evitar la aparición del síndrome de médula fijada. Pacientes y métodos. Revisión retrospectiva de las historias de los pacientes operados de MMC (n=162) y de espina bífida oculta (n=54) en el período 1975-2005 que desarrollaron cuadros de anclaje medular sintomático. Resultados. Once pacientes con MMC (6,79%) y dos con LMC (3,7%) presentaron manifestaciones de anclaje medular tras intervalos de 2 a 37 años después de la reparación primaria. Las indicaciones de reintervención se basaron fundamentalmente en criterios clínicos. Un hallazgo constante fue la fibrosiscicatricial que estuvo presente en todos los casos. Otros hallazgos operatorios causantes de la fijación medular consistieron en tumores cutáneos de inclusión (n=3),reacciones de cuerpo extraño (n=2), estenosis del canal lumbar (n=2), restos de lipoma (n=1), y filumhialinizado (n=1). En 3 casos de MMC se encontróademás un quiste epidermoide intradural (1,85% delos MMC), lo que supone una tasa de epidermoides en la reintervención de MMC de 27%. El periodo medio de seguimiento fue de 5,5 años y los resultados fueron: mejoría en 8, dos no experimentaron cambios, y uno sufrió empeoramiento. Conclusiones. El deterioro neurológico de los pacientes operados de MMC o LMC no constituye una consecuencia obligada o parte de la historia natural de estos procesos. El deterioro, precoz o tardío, puede estar motivado por el anclaje posquirúrgico de la médula espinal. Ello hace necesario realizar un seguimiento periódico de estos pacientes, acompañado de los oportunos estudios de neuroimagen y, en su caso, de exploración quirúrgica. Los resultados fueron satisfactorios, ya que el 92% de los pacientes reoperados experimentaron mejoría o estabilización de su enfermedad. Se describen además dos causas infrecuentemente descritas de deterioro tardío: la estenosis del canal y las reacciones fibrosas de cuerpo extraño a materiales implantados

Background. Spinal cord rethetering can occur after the primary surgical repair of myelomeningoceles (MMC) and lipomeningoceles (LMC) and produced evastating physical and psychological consequences.The inadvertent introduction of skin elements at the time of the initial surgery can lead to the growth of intraspinal epidermoid or dermoid cysts. Objectives. To review the incidence of spinal cord tethering following surgery for open and occult spinaldys raphism and to analyze factors that might influence the appearance of this complication. We also aimed to search technical measures at the time of the primary operation that might prevent the occurrence of symptomatic cord retethering. Material and methods. We reviewed the medical records of patients submitted to surgical repair of MMC (n=162) or occult spinal dysraphism (n= 54) during the period 1975-2005 who developed symptomatic tethered cord syndrome. Results. Eleven of 162 (6.79%) patients with MMCand 2 of 54 (3.7%) with LMC developed clinical symptoms and signs of spinal cord tethering after intervals ranging from 2 to 37 years after the initial surgical repair of their back lesions. Indications for surgical re-exploration were based mainly on clinical grounds. Postoperative fibrosis was a constant finding in all instances. Other surgical findings included inclusion tumors of cutaneous origin (n=3), lumbar canal stenosis(n= 2), foreign body reactions (n= 2), residual lipoma (n= 1), and a tight hyalinized filum (n=1). Interestingly,3 of 162 (or 1.85%) myelomeningoceles were found to harbor an intradural epidermoid tumor at the time of spinal cord dethetering, accounting for an incidence of cutaneous inclusion tumors of 27% in cases of post-MMC repair tethering. After a mean follow-up time of 5.5 years, eight patients were improved, two were unchanged and one was worsened. Conclusions. Neurological deterioration is not a necessary consequence of the natural history of patients with MMC or LMC. Early or late clinical deterioration can be due to spinal cord re-tethering and deserves timely investigation and surgical exploration. Results of surgical intervention were rewarding as 92% of the patients showed improvement or stabilization in their otherwise deteriorating condition. We also report two infrequent causes of spinal cord deterioration: lumbar canal stenosis and intense foreign-body reactions to implanted materials

Lower limb arterial incompressibility and obstruction in rheumatoid arthritis.

BACKGROUND: Despite increased cardiovascular morbidity and mortality in rheumatoid arthritis, the peripheral arteries remain understudied. OBJECTIVE: To examine the lower limb arteries in age and sex matched, non-smoking subjects with and without rheumatoid arthritis. METHODS: The ankle-brachial index (ABI) was measured at the posterior tibial and dorsal pedal arteries. Arteries were classified as obstructed with ABI < or =0.9, normal with ABI >0.9 but < or =1.3, and incompressible with ABI >1.3. Multinomial logistic regression was used to estimate differences in ABI between patients and controls, adjusting for cardiovascular risk factors, rheumatoid arthritis manifestations, inflammation markers, and glucocorticoid dose. RESULTS: 234 patients with rheumatoid arthritis and 102 controls were studied. Among the rheumatoid patients, 66 of 931 arteries (7%) were incompressible and 30 (3%) were obstructed. Among the controls, three of 408 arteries (0.7%) were incompressible (p = 0.002) and four (1%) were obstructed (p = 0.06). At the person level, one or more abnormal arteries occurred among 45 rheumatoid patients (19%), v five controls (5%, p = 0.001). The greater frequency of arterial incompressibility and obstruction in rheumatoid arthritis was independent of age, sex, and cardiovascular risk factors. Adjustment for inflammation markers, joint damage, rheumatoid factor, and glucocorticoid use reduced rheumatoid arthritis v control differences. Most arterial impairments occurred in rheumatoid patients with 20 or more deformed joints. This subgroup had more incompressible (15%, p< or =0.001) and obstructed arteries (6%, p = 0.005) than the controls, independent of covariates. CONCLUSIONS: Peripheral arterial incompressibility and obstruction are increased in rheumatoid arthritis. Their propensity for patients with advanced joint damage suggests shared pathogenic mechanisms.

Neuropsychiatric syndromes in lupus: prevalence using standardized definitions.

OBJECTIVE: The San Antonio Lupus Study of Neuropsychiatric Disease is a longitudinal study designed to characterize the spectrum of and important risk factors for specific neuropsychiatric systemic lupus erythematosus (NPSLE) syndromes. METHODS: Subjects must meet criteria for SLE and must be at least 18 years of age. A standardized medical history, neurologic, rheumatologic, and psychiatric examinations, computerized neuropsychological evaluation, and serologic testing are performed. RESULTS: This report is based on the first 128 subjects (120 women and 8 men) who completed the initial study visit. Data from this initial study visit were evaluated for the prevalence of NPSLE using the American College of Rheumatology case definitions for 19 NPSLE syndromes. One or more NPSLE syndromes were present in 80% of subjects: cerebrovascular disease (2, 2%; ischemic stroke); headaches (73, 57%); mononeuropathy (9, 8%; median 8, ulnar 1); movement disorder (1, 1%; chorea); neuropathy, cranial (2, 2%; trigeminal); polyneuropathy (29, 22%; sensorimotor); seizures (21, 16%; partial); anxiety disorder (27, 24%); major depressive-like episode (37, 28%); mood disorder with depressive features (21, 19%); mood disorder with manic features (3, 3%); mood disorder with mixed features (1, 1%); psychosis (6, 5%). In a subset of 67 patients who received standardized neuropsychological testing, 21% had normal results. In the remainder, the following levels of impairment were seen: 43% mild, 30% moderate, and 6% severe. CONCLUSIONS: The prevalence of NPSLE was high in this cohort of unselected patients with SLE. Headaches, cognitive dysfunction, and psychiatric disorders were the most common NPSLE syndromes seen. These results will be easily comparable to other studies also using standardized diagnostic criteria. However, the lack of ethnicity and language-matched normative neuropsychological data may make comparisons of cognitive dysfunction in SLE populations difficult.

Epidemiology and impact of rheumatic disorders in the United States Hispanic population.

The emergence of a sizable Hispanic population in the US is a relatively recent historical phenomenon, and thus much is still unknown about this group of North Americans. Data from national surveys suggest small differences between Hispanic and non-Hispanic white populations in the age-adjusted prevalence of self-reported arthritic conditions. However, the rate of activity-limitation attributable to arthritis is higher among Hispanic patients. This likely reflects the poorer socioeconomic conditions and lack of health insurance that prevail among Hispanic populations, which may limit their access to rheumatologic care. Osteoporotic vertebral and hip fractures are less frequent, and proximal femoral mineral density is higher, in Hispanic individuals than in non-Hispanic white individuals. The mechanisms for these observations are currently under investigation. There have been no studies of the prevalence of osteoarthritis, rheumatoid arthritis, or systemic lupus erythematosus among Hispanic populations. However, important immunogenetic, clinical, and psychosocial differences between Hispanic and non-Hispanic patients in regard to rheumatoid arthritis and systemic lupus erythematosus have been reported. There is no published information on the prevalence or characteristics of other rheumatic diseases in the US Hispanic population. Emerging evidence suggests considerable underuse of certain health services for arthritis among Hispanic patients, likely due in part to socioeconomic factors. Further research is needed to determine whether biologic, cultural or psychosocial factors contribute to underuse as well. There is clearly a need for data on the prevalence and characteristics of arthritis and other rheumatic and musculoskeletal diseases in this emerging US population.

High incidence of cardiovascular events in a rheumatoid arthritis cohort not explained by traditional cardiac risk factors.

OBJECTIVE: To compare the incidence of cardiovascular (CV) events in persons with rheumatoid arthritis (RA) with that in people from the general population, adjusting for traditional CV risk factors. METHODS: Two hundred thirty-six consecutive patients with RA were assessed for the 1-year occurrence of 1) CV-related hospitalizations, including myocardial infarction, stroke or other arterial occlusive events, or arterial revascularization procedures, or 2) CV deaths. Both outcomes were ascertained by medical records or death certificates. For comparison, we used CV events that occurred during an 8-year period among participants in an epidemiologic study of atherosclerosis and CV disease who were ages 25-65 years at study entry. We calculated the age- and sex-stratified incidence rate ratio (IRR) of CV events between the 2 cohorts and used Poisson regression to adjust for age, sex, smoking status, diabetes mellitus, hypercholesterolemia, systolic blood pressure, and body mass index. RESULTS: Of the 236 RA patients, 234 were observed for 252 patient-years, during which 15 CV events occurred. Of these, 7 incident events occurred during the 204 patient-years contributed by patients ages 25-65 years, for an incidence of 3.43 per 100 patient-years. In the comparison cohort, 4,635 community-dwelling persons were followed up for 33,881 person-years, during which 200 new events occurred, for an incidence of 0.59 per 100 person-years. The age- and sex-adjusted IRR of incident CV events associated with RA was 3.96 (95% confidence interval [95% CI] 1.86-8.43). After adjusting for CV risk factors using Poisson regression, the IRR decreased slightly, to 3.17 (95% CI 1.33-6.36). CONCLUSION: The increased incidence of CV events in RA patients is independent of traditional CV risk factors. This suggests that additional mechanisms are responsible for CV disease in RA. Physicians who provide care to individuals with RA should be aware of their increased risk of CV events and implement appropriate diagnostic and therapeutic measures.

Delineation of the human systemic lupus erythematosus anti-Smith antibody response using phage-display combinatorial libraries.

The anti-Smith (Sm) autoantibody response is highly specific for systemic lupus erythematosus and is predominantly targeted to the Sm-B/B' and -D1 polypeptides. In all animal species thus far studied, anti-Sm Abs initially recognize proline-rich epitopes in the carboxyl terminus of the Sm-B/B' protein and subsequently to multiple other epitopes in B/B' and D. The absence of appropriate mAbs has limited our understanding of the genetic and structural basis of this autoimmune response. Using phage-display technology and lymphocytes from a systemic lupus erythematosus patient we have generated the first and only panel of human IgG anti-Sm mAbs thus far available. These Abs reproduced to a remarkable extent the serological reactivity of the patient. Epitope mapping and genetic studies revealed that the anti-Sm response is produced by distinct B cell clones with restricted epitope reactivity. All of the Abs in our study were exclusively encoded by different members of the V(H)4 gene family. On the aggregate, our results demonstrate that combinatorial libraries can recapitulate the immune repertoire of peripheral blood B memory cells and that epitope spreading appears to occur through the sequential recruitment of nonclonally related autoreactive B cell clones.

Recipients of hip replacement for arthritis are less likely to be Hispanic, independent of access to health care and socioeconomic status.

OBJECTIVE: To compare the proportion of Hispanics among recipients of hip replacements for primary articular disorders, recipients of knee replacements for the same reason, and persons hospitalized for other reasons. METHODS: Twelve of the 17 accredited hospitals in Bexar County, Texas, in which hip or knee replacement surgery is performed permitted us to review their medical records. From 1993 through 1995, 3,100 elective, non-fracture-related, hip or knee replacements were performed. These individuals were matched by age, sex, hospital, and month of admission with 4,604 persons hospitalized for other reasons. Age, sex, ethnic background, type of medical insurance, median household income by zip code of residence, joint replaced, and surgical diagnosis were abstracted from the medical records. The validity of variables abstracted from the medical records was tested by comparison with self-report data in 115 patients interviewed prior to elective hip or knee replacement surgery. RESULTS: During the study period, 2,275 subjects had a total knee replacement and 825 had a total hip replacement. Recipients of hip replacements were significantly less likely to be Hispanic than were recipients of knee replacements (19.5% versus 29.9%; odds ratio [OR] 0.57, 95% confidence interval [95% CI] 0.46-0.71; P < or = 0.001) or persons hospitalized for other reasons (29.4% Hispanic; OR 0.67, 95% CI 0.55-0.81). The under-representation of Hispanics was more pronounced among persons undergoing hip replacement for osteoarthritis compared with recipients of knee replacements for the same disease (OR 0.48, 95% CI 0.37-0.62). This pattern persisted after adjusting for age, sex, type of medical insurance, and median household income by the zip code of residence. Concordance between medical records and self-report data on ethnic background was high (kappa = 0.93). CONCLUSION: Recipients of hip replacement are less likely to be Hispanic than are other hospitalized persons with a similar level of access to care. The reasons for this under-representation probably involve factors in addition to lack of access to health care and low socioeconomic status. Further research is needed to understand the nature of such factors.

Ventriculopleural shunting with new technology valves.

Ventriculoperitoneal shunting constitutes the standard procedure for draining cerebrospinal fluid (CSF) in children with hydrocephalus. Ventriculoatrial and ventriculopleural shunting are alternative methods of CSF drainage, which have gained less acceptance. Ventriculopleural shunts are seldom used owing to justified fears of pneumothorax and symptomatic effusions of CSF. The addition of an antisiphon device to standard shunt systems seems to have prevented CSF pleural effusion. From 1988 to 1998, we treated each of six hydrocephalic children with a ventriculopleural shunt. In five cases we used new-technology valves designed to prevent the effects of siphoning with current differential pressure valves. Peritoneal adhesions, recent peritonitis, ascites, and obstruction of a previous ventriculoatrial shunt were the indications for pleural shunting. After a mean follow-up period of 2.5 years all shunts were functioning adequately. Only one patient showed transient symptoms of CSF overdrainage, which were corrected by up-grading the valve setting with the magnet. A late death was unrelated to the pleural shunting procedure. The use of valves of a new design designed to prevent overdrainage seems to account for the satisfactory outcomes observed in this series. We suggest that ventriculopleural shunting should be considered as the preferred alternative to peritoneal drainage in children with intra-abdominal adhesions or with a history of recent peritoneal infection.

Symptoms of depression and psychological distress among Hispanics with rheumatoid arthritis.

OBJECTIVE: To explore the roles played by Hispanic ethnic background and acculturation to the mainstream English language culture of the United States in the depressive symptoms and mental health of rheumatoid arthritis (RA) patients. METHODS: Members of a consecutive cohort of patients with RA were studied cross-sectionally. All underwent a comprehensive clinical and psychosocial evaluation. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression Scale (CES-D), and psychological distress was measured with the Medical Outcomes Study Short Form 36 (SF-36) mental health scale. RESULTS: Two hundred thirty-six patients were studied. Women had significantly higher median CES-D scores than men (19 versus 14, P = 0.0004), Hispanics scored higher than non-Hispanics (14 versus 8, P = 0.0002), and foreign-born scored higher than US-born patients (14 versus 10, P = 0.009). Compared with those who were fully acculturated, patients who were partially acculturated were more likely to have a score > or = 16 on the RA-adjusted CES-D (odds ratio [OR] = 1.79, 95% confidence interval [95% CI] 1.37 to 2.35, P < or = 0.001). Among unacculturated patients, the likelihood of a score > or = 16 increased 6-fold (OR = 6.68; 95% CI 3.50 to 12.72; P < or = 0.001). A similar, inverse pattern was observed for the SF-36 mental health scale. In multivariate models accounting for age, sex, education, income, articular pain, deformity, and the level of disability, low acculturation was independently associated with high depressive symptoms, and a Hispanic background was independently associated with lower SF-36 mental health. CONCLUSIONS: In this consecutive series of RA patients, Hispanics, particularly those who are not fully acculturated to the mainstream Anglo society, had more depressive symptoms and psychological distress than did non-Hispanics.

How much disability in rheumatoid arthritis is explained by rheumatoid arthritis?

OBJECTIVE: To measure the proportion of disability explained by disease manifestations compared with nondisease factors in rheumatoid arthritis (RA). METHODS: A hypothetical model of the disablement process specific for RA was constructed using the demographic, sociocultural, and clinical characteristics of a consecutive cohort of RA patients. Disability was measured with the modified Health Assessment Questionnaire (M-HAQ) and the physical function scale of the Medical Outcomes Study Short Form 36 (SF-36) questionnaire. Independent variables, grouped according to their position in the RA disablement process model, were sequentially entered in a series of hierarchical regression models. The proportion of variance in disability explained by each group of variables was measured by the group's incremental R2. RESULTS: The overall proportion of disability explained by the full model was 59%. Factors in the main disease-disability pathway explained 33%, of which 3% was explained by disease duration, 5% by the Westergren erythrocyte sedimentation rate, 14% by articular signs and symptoms, and 11% by performance-based functional limitations. External modifiers and contextual variables explained 26% of the variance in disability, of which age and sex accounted for 2%, formal education 4%, psychological status 17%, and symptoms of depression 3%. CONCLUSION: Both the main disease-disability pathway and factors external to this pathway contribute significantly to disability in RA. These findings provide evidence of the relative influence of psychosocial factors, compared with disease manifestations, on the disability of patients with RA.

HLA-DRB1 alleles associated with susceptibility or resistance to rheumatoid arthritis, articular deformities, and disability in Mexican Americans.

OBJECTIVE: To study the genetics (HLA-DRB1 allele associations) of rheumatoid arthritis (RA) susceptibility and severity among Mexican Americans, an important, but understudied, US population. METHODS: HLA-DRB1 alleles were compared between 141 Mexican American patients with RA and 54 unrelated Mexican Americans without RA, and the association of these alleles with articular deformities and disability was examined. HLA-DRB1 alleles were typed using polymerase chain reaction-sequence-specific primer amplification and were classified according to the 1996 World Health Organization nomenclature. RESULTS: Of the 141 patients, 105 (74%) had at least 1 copy of the shared epitope (SE) sequence, compared with 29 (54%) of the 54 controls (P = 0.007). A significant gene-dose effect was observed, with 31 patients (22%) being homozygous for the SE compared with 1 (2%) of the controls (P = 0.004). In terms of disease severity, only 3% of RA patients who were "null" for the SE were outliers in the rate of development of articular deformities, compared with 10% of heterozygotes and 27% of homozygotes (P = 0.002). Patients who were DRB1*08 positive had significantly fewer deformities per year of disease and a slower rate of development of disability than did patients with other DRB1 alleles. CONCLUSION: HLA-DRB1 alleles containing the SE are associated with susceptibility to RA in Mexican Americans, and may also be associated with a more rapid development of articular deformities and disability. HLA-DRB1*08 appears to have a protective influence on RA susceptibility and disease severity in Mexican Americans.

Cross-cultural equivalence of a brief helplessness scale for Spanish-speaking rheumatology patients in the United States.

OBJECTIVE: To show evidence of the cross-cultural equivalence between the original English version of a 5-item scale for measuring helplessness and a translated Spanish version. METHODS: English and Spanish versions of the 5 items that constitute the helplessness factor of the Rheumatology Attitudes Index were tested in 3 separate groups of patients: 1) 20 bilingual rheumatology patients; 2) 100 consecutive English- and 50 consecutive Spanish-speaking monolingual rheumatology patients; and 3) 192 English- and 44 Spanish-speaking patients with rheumatoid arthritis who were consecutively enrolled in a cohort to study disease outcomes. English-Spanish concordance among bilingual subjects was measured using intraclass correlation coefficients (ICC). Internal consistency was measured by Cronbach's coefficient alpha. Associations between the helplessness scale and variables measured simultaneously in English- and Spanish-speaking patients were measured by correlation analysis. RESULTS: Agreement between the English and Spanish versions of the helplessness scale among bilingual subjects was excellent (ICC = 0.87), and internal consistency among monolingual subjects was acceptable (coefficient alpha = 0.73 in English and 0.87 in Spanish). The correlation between helplessness and most other measured variables was of similar size and direction in English as in Spanish (10-point pain scale r = -0.53 and -0.52; modified Health Assessment Questionnaire physical disability r = -0.45 and -0.43; self-assessed joint count r = 0.36 and 0.36; Medical Outcomes Study Short Form 36 [SF-36] physical function r = 0.37 and 0.39; SF-36 mental health r = 0.27 and 0.35; Center for Epidemiological Studies Depression scale r = -0.37 and -0.33, respectively). CONCLUSION: The evidence shown supports the cross-cultural equivalence between the original 5-item helplessness scale developed in English and our translated Spanish version.