Local Bone Grafting Is Sufficient for Instrumented Adolescent Idiopathic Scoliosis Surgery: A Preliminary Study

BACKGROUND

Several options for grafting exist; iliac crest bone grafting, allografts, and bone substitutes. Local bone graft (LBG) offers high-quality bone graft and no commercial cost. The aim of this study was to assess the clinical and radiologic results of adolescent idiopathic scoliosis (AIS) surgery with posterior instrumentation and fusion (PIF) in patients using only LBG and to measure the quantities harvested.

METHODS

A total of 218 AIS patients who underwent pedicle screw PIF surgery using only LBG with a minimum 1-year follow-up were reviewed. Bone was harvested during surgery from the excised facet joints, spinous processes (not from the end instrumented vertebrae) and decortication of laminae and transverse processes in the operative field. The harvested bone graft weight of 127 patients was recorded prospectively and then computed to graft weight per kilogram body weight (GWPK) and graft weight per motion segment (GWPMS).

RESULTS

The median follow-up time was 24.7 months (12.1 to 133 mo) with 128 of the 218 patients having over 2 years follow-up. A total of 280 curves were fused. One hundred fifty-six of the patients had single curve instrumentation and 62 had double curve surgery. The median preoperative primary Cobb angle was 57.0 (31 to 100) degrees and postoperatively was 20.0 (0 to 66) degrees, indicating a median correction of 65.3% (17.5% to 100%). The median graft weight was 30 g (14 to 62 g), GWPK was 0.54 g/kg (0.24 to 1.29 g/kg) and GWPMS was 3.3 g/motion segments (2.3 to 10.0 g/kg). Twelve of 218 patients (5.5%) required subsequent surgery. Only 2 patients developed pseudarthrosis (0.91%), noting that modern segmental instrumentation warrants longer follow-up for increased confidence of complete fusion.

CONCLUSIONS

LBG achieved successful fusion in over 99% of patients undergoing PIF for AIS. The described terms GWPK and GWPMS can be insightful for future studies. LBG offers a safe and low-cost solution for bone grafting in AIS surgery.

LEVEL OF EVIDENCE

Level IV.

Concerns About the Registered Behavior Technician™ in Relation to Effective Autism Intervention

In 2014, the Behavior Analyst Certification Board (BACB®) initiated a program for credentialing behavior technicians. The new credential, Registered Behavior Technician™ (RBT®), is for providers of behavioral intervention to a wide range of individuals with mental health needs and developmental delays, including individuals diagnosed with autism spectrum disorder (ASD). The RBT® would represent the entry-level position within the range of the BACB® credentials. Despite the increasing acceptance of this newest level of credential from the behavioral community, the authors of this paper have substantial concerns with the RBT® credential as it relates to the delivery of intervention to individuals diagnosed with ASD. The purpose of this paper is to detail these concerns and propose remedies that would ensure that individuals diagnosed with ASD receive effective behavioral intervention.

Laminated multi-segment rib graft in anterior column reconstruction

Rib harvested during thoracotomy can be effectively used for anterior column reconstruction. An innovative technique is described to convert multiple individual rib segments into a robust single anterior column reconstruction graft using cortical screws.

Anterior thoracoscopic surgery followed by posterior instrumentation and fusion in spinal deformity

Many authors believe thoracoscopic surgery is associated with a lower level of morbidity compared to thoracotomy, for anterior release or growth arrest in spinal deformity. Others believe that anterior release achieved thoracoscopically is not as effective as that achieved with the open procedure. We evaluated the clinical results, radiological correction and morbidity following anterior thoracoscopic surgery followed by posterior instrumentation and fusion, to see whether there is any evidence for either of these beliefs. Twenty-nine patients undergoing thoracoscopic anterior release or growth arrest followed by posterior fusion and instrumentation were evaluated from a clinical and radiological viewpoint. The mean follow-up was 2 years (range 1-4 years). The average age was 16 years (range 5-26 years). The following diagnoses were present: idiopathic scoliosis (n = 17), neuromuscular scoliosis (n = 2), congenital scoliosis (n = 1), thoracic hyperkyphosis (n = 9). All patients were satisfied with cosmesis following surgery. Twenty scoliosis patients had a mean preoperative Cobb angle of 65.1 degrees (range 42 degrees-94 degrees) for the major curve, with an average flexibility of 34.5% (42.7 degrees). Post operative correction to 31.5 degrees (50.9%) and 34.4 degrees (47.1%) at maximal follow-up was noted. For nine patients with thoracic hyperkyphosis, the Cobb angle averaged 81 degrees (range 65 degrees-96 degrees), with hyperextension films showing an average correction to 65 degrees. Postoperative correction to an average of 58.6 degrees was maintained at 59.5 degrees at maximal follow-up. The average number of released levels was 5.1 (range 3-7) and the average duration of the thoracoscopic procedure was 188 min (range 120-280 min). There was a decrease in this length of time as the series progressed. No neurologic or vascular complications occurred. Postoperative complications included four recurrent pneumothoraces, one surgical emphysema, and one respiratory infection. Thoracoscopic anterior surgery appears a safe and effective technique for the treatment of paediatric and adolescent spinal deformity. A randomised controlled trial, comparing open with thoracoscopic methods, is required.

Mechanical initiation of intervertebral disc degeneration

STUDY DESIGN

Mechanical testing of cadaveric lumbar motion segments.

OBJECTIVES

To test the hypothesis that minor damage to a vertebral body can lead to progressive disruption of the adjacent intervertebral disc.

SUMMARY OF BACKGROUND DATA

Disc degeneration involves gross structural disruption as well as cell-mediated changes in matrix composition, but there is little evidence concerning which comes first. Comparatively minor damage to a vertebral body is known to decompress the adjacent discs, and this may adversely affect both structure and cell function in the disc.

METHODS

In this study, 38 cadaveric lumbar motion segments (mean age, 51 years) were subjected to complex mechanical loading to simulate typical activities in vivo while the distribution of compressive stress in the disc matrix was measured using a pressure transducer mounted in a needle 1.3 mm in diameter. "Stress profiles" were repeated after a controlled compressive overload injury had reduced motion segment height by approximately 1%. Moderate repetitive loading, appropriate for the simulation of light manual labor, then was applied to the damaged specimens for approximately 4 hours, and stress profilometry was repeated a third time. Discs then were sectioned and photographed.

RESULTS

Endplate damage reduced pressure in the adjacent nucleus pulposus by 25% +/- 27% and generated peaks of compressive stress in the anulus, usually posteriorly to the nucleus. Discs 50 to 70 years of age were affected the most. Repetitive loading further decompressed the nucleus and intensified stress concentrations in the anulus, especially in simulated lordotic postures. Sagittal plane sections of 15 of the discs showed an inwardly collapsing anulus in 9 discs, extreme outward bulging of the anulus in 11 discs, and complete radial fissures in 2 discs, 1 of which allowed posterior migration of nucleus pulposus. Comparisons with the results from tissue culture experiments indicated that the observed changes in matrix compressive stress would inhibit disc cell metabolism throughout the disc, and could lead to progressive deterioration of the matrix.

CONCLUSIONS

Minor damage to a vertebral body endplate leads to progressive structural changes in the adjacent intervertebral discs.

Assessment in multisite randomized clinical trials of patients with autistic disorder: the Autism RUPP Network. Research Units on Pediatric Psychopharmacology

Assessment of autistic disorder (autism) symptoms, primary and secondary, poses more challenging problems than ordinarily found in multisite randomized clinical trial (RCT) assessments. For example, subjects may be uncommunicative and extremely heterogeneous in problem presentation, and current pharmacological treatments are not likely to alter most core features of autism. The Autism Research Units on Pediatric Psychopharmacology (RUPP Autism Network) resolved some of these problems during the design of a risperidone RCT in children/adolescents. The inappropriateness of the usual anchors for a Clinical Global Impression of Severity (CGI-S) was resolved by defining uncomplicated autism without secondary symptoms as a CGI-S of 3, mildly ill. The communication problems, compromising use of the patient as an informant, were addressed by several strategies, including careful questioning of care providers, rating scales, laboratory tests, and physical exams. The broad subject heterogeneity requires outcome measures sensitive to individual change over a wide spectrum of treatment response and side effects. The problems of neuropsychologically testing nonverbal, lower functioning, sometimes noncompliant subjects requires careful instrument selection/adaptation and flexible administration techniques. The problems of assessing low-end IQs, neglected by most standardized test developers, was resolved by an algorithm of test hierarchy. Scarcity of other autism-adapted cognitive and neuropsychological tests and lack of standardization required development of a new, specially adapted battery. Reliability on the Autism Diagnostic Interview (currently the most valid diagnostic instrument) and other clinician instruments required extensive cross-site training (in-person, videotape, and teleconference sessions). Definition of a treatment responder required focus on individually relevant target symptoms, synthesis of possible modest improvements in many domains, and acceptance of attainable though imperfect goals. The assessment strategy developed is implemented in a RCT of risperidone (McDougle et al., 2000) for which the design and other methodological challenges are described elsewhere (Scahill et al., 2000). Some of these problems and solutions are partially shared with RCTs of other treatments and other disorders.

Effects of backward bending on lumbar intervertebral discs. Relevance to physical therapy treatments for low back pain

STUDY DESIGN

Mechanical testing of cadaveric motion segments.

OBJECTIVES

To test the hypothesis that backward bending of the lumbar spine can reduce compressive stresses within lumbar intervertebral discs.

SUMMARY OF BACKGROUND DATA

Lumbar extension affects the distribution of compressive stress inside normal cadaveric discs, but little is known about its effect on mechanically disrupted and degenerated discs.

METHODS

Nineteen lumbar motion segments (mean donor age, 48 years) were subjected to complex mechanical loading to simulate the following postures: moderate lumbar flexion, 2 degrees of extension, 4 degrees of extension, and the neutral position (no bending). The distribution of compressive stress within the disc matrix was measured in each posture by pulling a miniature pressure transducer along the midsagittal diameter of the disc. Stress profiles were repeated after a mechanical treatment that was intended to simulate severe disc degeneration in vivo.

RESULTS

The "degeneration" treatment reduced pressure in the nucleus pulposus and generated stress concentrations within the anulus, in a manner similar to that found in severely degenerated discs in vivo. When all discs were considered together, 2 degrees of extension increased the maximum compressive stress within the posterior anulus by an average of 16%, compared with the neutral posture. The size of localized stress peaks within the posterior anulus was increased by 43% (P = 0.02). In 4 degrees of extension, changes observed between 0 degree and 2 degrees were usually exaggerated. In contrast, moderate flexion tended to equalize the distribution of compressive stress. In 7 of the 19 discs, 2 degrees of lumbar extension decreased maximum compressive stress in the posterior anulus relative to the neutral posture by up to 40%. Linear regression showed that lumbar extension tended to reduce stresses in the posterior anulus in those discs that exhibited the lowest compressive stresses in the neutral posture (P = 0.003; R2 = 41%).

CONCLUSIONS

The posterior anulus can be stress shielded by the neural arch in extended postures, but the effect is variable. This may explain why extension exercises can relieve low back pain in some patients.

Research Units on Pediatric Psychopharmacology (RUPP) Autism Network. Background and rationale for an initial controlled study of risperidone

This article has reviewed the background and rationale for the choice of risperidone as the first drug to be studied by the RUPP Autism Network. Risperidone has potent effects on 5-HT and DA neuronal systems, both of which have been implicated in the pathophysiology of autism. Unlike the typical antipsychotics, haloperidol and pimozide, which have been shown to be effective for reducing many of the maladaptive behaviors associated with autism, risperidone's 5-HT2A/DA D2 ratio of receptor blockade appears to produce a lower risk of acute and chronic extrapyramidal side effects, as well as enhanced efficacy for the "negative" symptoms of autism. Indirect clinical and preclinical evidence supports the use of risperidone to treat impaired social behavior, interfering repetitive phenomena, and aggression, targets of pharmacotherapy for many patients with autism. Numerous published open-label trials in children and adolescents with autism and related PDDs and one double-blind, placebo-controlled study in adults suggest that risperidone has promise for the treatment of children and adolescents with autism. Because most of these studies have been short-term, open-label trials in small samples, however, a large-scale controlled study of risperidone in children and adolescents with autism is needed to confirm these results. Finally, because it is likely that children who demonstrate short-term benefit from risperidone will remain on the medication indefinitely, the longer-term effectiveness and safety of risperidone in this population also needs to be determined. The design of this study and the assessments used are described separately.

Vineland Adaptive Behavior Scale scores as a function of age and initial IQ in 210 autistic children

Human growth modeling statistics were utilized to examine how Vineland Adaptive Behavior Scale (VABS) scores changed in individuals with autistic disorder as a function of both age and initial IQ. Results revealed that subjects improved with age in all domains. The rate of growth in Communication and Daily Living Skills was related to initial IQ while rate of growth in Social Skills was not. Results should provide hope for parents and further support for the importance of functional social-communication skills in the treatment of autism.

Behavior and therapeutic efficacy of beta-glucuronidase-positive mononuclear phagocytes in a murine model of mucopolysaccharidosis type VII

Bone marrow transplantation (BMT) is relatively effective for the treatment of lysosomal storage diseases. To better understand the contribution of specific hematopoietic lineages to the efficacy of BMT, we transplanted beta-glucuronidase-positive mononuclear phagocytes derived from either the peritoneum or from bone marrow in vitro into syngeneic recipients with mucopolysaccharidosis type VII (MPS VII). Cell surface marking studies indicate that the bone marrow-derived cells are less mature than the peritoneal macrophages. However, both cell types retain the ability to home to tissues rich in cells of the reticuloendothelial system after intravenous injection into MPS VII mice. The half-life of both types of donor macrophages is approximately 7 days, and some cells persist for at least 30 days. In several tissues, therapeutic levels of beta-glucuronidase are present, and histopathologic analysis demonstrates that lysosomal storage is dramatically reduced in the liver and spleen. Macrophages intravenously injected into newborn MPS VII mice localize to the same tissues as adult mice but are also observed in the meninges and parenchyma of the brain. These data suggest that macrophages play a significant role in the therapeutic efficacy of BMT for lysosomal storage diseases and may have implications for treatments such as gene therapy.

End caps for the intramedullary nail: a help or a hindrance?

End caps on intramedullary nails are intended to facilitate removal and to allow length adjustment of the nail in situ. A case is reported in which the end cap made nail removal technically more difficult.

The extended lateral approach to the hindfoot. Anatomical basis and surgical implications

We have recently described an extended lateral approach to the hindfoot for the operative treatment of displaced intra-articular fractures of the calcaneum. It has the advantage of avoiding damage to the sural nerve and preserving blood supply to allow prompt healing. We dissected 15 formalin-preserved cadavers, taking photographs to show the structures of the posterolateral aspect of the hindfoot and ankle. We describe a superficial and a deep triangle: the deep triangle contains a constant posterior peroneal artery which supplies the skin of the posterolateral heel. An approach designed to expose the sural nerve will divide this important artery and cause ischaemia of the posterior skin. The extended lateral approach elevates the sural nerve in a thick flap and preserves the blood supply of the skin. We have reviewed 150 consecutive patients after the use of this approach to study the indications for operation, the quality of wound healing, any damage to the sural nerve and other complications. We recommend the careful use of this approach. Our understanding of its anatomical basis has allowed us to widen the indications for its use.

Blood loss in sequential bilateral total knee arthroplasty

This study was devised to determine whether blood loss for sequential bilateral knee arthroplasties was the same for the first and second knees. Twenty-eight patients who underwent this procedure were studied along with a control group of patients who underwent unilateral knee arthroplasties. Blood loss was greater in the second knee by a mean of 323 mL (P < .05). The control group and the first knee showed no significant difference in blood loss. Analysis of clotting studies showed a prolongation of prothrombin time, activated partial thromboplastin time, and thrombin time after release of the first tourniquet. Possible reasons for this greater blood loss are discussed.

Guidelines for evaluating intervention programs for children with autism

It is now well recognized that early diagnosis and intervention improves the prognosis for children with autism. It is crucial that professionals be aware and sensitive to the needs of autistic persons and their families. We must never lose sight of the long-term goal of treatment and must not become so infatuated with any one treatment that we fail to provide the education parents need. It is incumbent upon us, as professionals, to educate parents and help them evaluate the myriad of information with which they are bombarded. In this article a framework for thinking about autism and principles of evaluation are reviewed. Components of appropriate early intervention programs are then described and guidelines for evaluating alternative treatments are provided.

Spontaneous rupture of the anterior cruciate ligament after anabolic steroids

Anabolic steroids remain popular among body builders and power athletes despite numerous warning about their side effects. A case of spontaneous rupture of the anterior cruciate ligament is reported in a bodybuilder taking steroids. While there are many published reports of tendon rupture associated with steroid intake, the authors could find no report relating to ligament disruption.

Synchronous proctocolectomy and ileoanal pouch formation and the risk of Crohn's disease

There is controversy on the advisability of one-stage proctocolectomy and the formation of an ileoanal pouch. Accurate preoperative diagnosis is essential to avoid the error of constructing a pouch in a patient with Crohn's disease. Twenty-four consecutive patients undergoing subtotal colectomy for inflammatory bowel disease were reviewed. All patients had been treated with systemic steroids, 23 were on 5-aminosalicylates and 11 on azathioprine. The preoperative diagnoses, based on a combination of clinical features, colonoscopy, barium enema and biopsy histology, were ulcerative colitis (19), Crohn's disease (four) and inflammatory bowel disease (unclassified) (one). The final diagnosis was made on histological examination of the resected specimen. A discrepancy between initial and final diagnosis occurred in eight patients. In three, the diagnosis was changed from ulcerative colitis to Crohn's disease. Three preoperative diagnoses of Crohn's disease were changed to ulcerative colitis (one), Behçet's disease (one) and diverticulitis (one) on final histology. These data suggest that caution should be exercised in performing synchronous proctocolectomy with the formation of an ileoanal pouch.

Field trial for autistic disorder in DSM-IV

OBJECTIVE

This project focused on the development of the definition of autism for DSM-IV.

METHOD

Multiple sites were involved in obtaining information regarding 977 patients with the following clinician-assigned diagnoses: autism (N = 454), other pervasive developmental disorders (N = 240), and other disorders (N = 283). A standard coding system was used, and the raters (N = 125) had a range of experience in the diagnosis of autism. Patterns of agreement among existing diagnostic systems were examined, as was the rationale for inclusion of other disorders within the class of pervasive developmental disorders.

RESULTS

The DSM-III-R definition of autism was found to be overly broad. The proposed ICD-10 definition most closely approximated the clinicians' diagnoses. Inclusion of other disorders within pervasive developmental disorders appeared justified. Partly on the basis of these data, modifications in the ICD-10 definition were made; this and the DSM-IV definition are conceptually identical.

CONCLUSIONS

The resulting convergence of the DSM-IV and ICD-10 systems should facilitate both research and clinical service.

Comparison between diagnostic instruments for identifying high-functioning children with autism

Two instruments for identifying autism in children and adolescents with intellectual abilities in the normal range were compared. Diagnostic tools consisted of the Autism Behavior Checklist (ABC) and the Autism Diagnostic Interview (ADI). The sample was composed of 18 children who were all diagnosed as having either infantile autism or infantile autism, residual state based on DSM-III criteria by a clinical team using observations, parental interviews, and interactions with the children. Only 4 of the children met diagnostic cutoffs for autism on the current ABC but all met criteria for diagnosis on the ABC using parental recall of the child's behavior at 3-5 years of age. The ADI had somewhat greater specificity in that 3 children did not meet criteria for diagnosis although 2 of these children also received ABC scores based on parental recollection that were in the borderline range.

Analysis of environmental deprivation: cognitive and social development in Romanian orphans

The cognitive and social developmental status of a representative group of Romanian orphans between the ages of 23 and 50 months living in the Leagan de Copii in Timisoara, Romania was assessed using a variety of traditional and nontraditional measures. Results indicated that the orphanage sample all exhibited deficits in cognitive and social functioning; the majority were severely delayed. Correlations between the traditional and nontraditional measures indicated that children's delays occurred across domains. Deficits were not related to length of time in the orphanage, age at entrance, Apgar scores, or birthweight. The children's greatest capability was in peer social interaction.

Clinical characteristics of mild autism in adults

Clinical descriptions of 14 adults with mild autism are presented. Structured questionnaires, extensive medical and social histories, and mental status examinations were conducted independently by several clinicians who concurred with the diagnoses of autism. These 14 patients demonstrate (1) that mild forms of autism can remain undiagnosed into adulthood; (2) that developmental histories and patients' reports may not provide evidence of developmental delays and characteristic symptoms during childhood despite their presence at adult mental status examination; (3) that mild previously undetected autism should be considered in the differential diagnoses of perplexing adult patients.

The UCLA-University of Utah epidemiologic survey of autism: Recurrent infections

Two hundred and forty-one children with autism were ascertained and diagnosed (DSM-III criteria) in an epidemiologic survey of Utah. Pediatric and other pertinent medical records were abstracted for 233 patients and 66 of their siblings without autism for otitis media, upper respiratory, and other infections. A significantly greater number of children with autism had recurrent otitis media, upper respiratory and other infections than their nonautistic siblings. A greater number of children with autisru with recurrent infections had lower IQ scores, seizures, hearing deficits, delayed motor milestones, poorer speech, congenital anomalies, feeding problems, vomiting, diarrhea, and other types of infections than children with autism with mild or no infections. The only significant pre-, peri-, or postnatal risk factors between children with autism with recurrent, mild or no infection was an increase in the maternal-fetal incompatibility (ABO or Rh) in the recurrent infection group. Half the families with more than one child with autism had recurrent infections and 72% of those children with concurrent diseases which effect the CNS had recurrent infections. Methodological limitations are discussed.

Complex segregation analysis of autism

A complex segregation analysis of autism in 185 Utah families was carried out using the mixed model. The 209 affected individuals in these families represent nearly complete ascertainment of the autistic cases born in Utah between 1965 and 1984. The sibling recurrence risk for autism was 4.5% (95% confidence limits 2.8%-6.2%). Likelihoods were maximized for major-gene models, a polygenic model, a sibling-effect model, and a mixed model consisting of major-gene and shared-sibling effects. The analysis provided no evidence for major-locus inheritance of autism. Subdivision of the sample according to the probands' IQ levels showed that sibling recurrence risk did not vary consistently with IQ level. A segregation analysis of families in which the proband had an IQ less than 50 also failed to provide evidence for a major locus. However, because of the etiologic heterogeneity of this disorder, genetic analysis of other meaningful subsets of families could prove informative.

The stability of cognitive and behavioral parameters in autism: a twelve-year prospective study

Sixty-two autistic patients enrolled in a prospective study an average of 12 years ago. Current retesting results are now available on 53 of the original 62 patients (85.5%). Results indicate that 36 (67.9%) achieved scores within their original IQ group. Twelve (22.6%) moved up IQ groups and five (9.4%) moved down. Of particular clinical importance is the observation that Vineland Adaptive Behavior Scores were consistently lower than cognitive scores, and maladaptive behaviors occurred with equal frequency in the high, medium, and low IQ groups. The implications of this new data for understanding the natural history of autism, educational and vocational planning, and future research are discussed.

The UCLA-University of Utah epidemiologic survey of autism: the etiologic role of rare diseases

Twelve rare diseases known to cause CNS pathology were found in 26 (11%) of 233 autistic probands identified during a recent epidemiologic survey of Utah. These 26 probands had significantly lower mean IQs than the remaining patients (43 versus 60) but similar sex distribution and prevalence of abnormal EEGs and seizures. The rarity and diversity of these 12 diseases make it highly unlikely that they randomly occurred with autism. Their presence in this epidemiologic survey is the most compelling evidence to date to support the hypothesis that different diseases producing different types of CNS pathology can play an etiologic role in autism.

The UCLA-University of Utah epidemiologic survey of autism: prenatal, perinatal, and postnatal factors

In a recent epidemiologic survey conducted in Utah, 241 autistic patients (DSM-III criteria) were found. Medical records of 233 autistics were surveyed for the presence of 36 potentially pathologic prenatal, perinatal, and postnatal factors. These results were compared with those of an identical survey of 62 of their nonautistic siblings, with the results of four previously published surveys, and with normative data. No potentially pathologic factor or group of factors occurred significantly more frequently among the autistic patients. Also, previous observations of significant differences in the occurrence of certain factors in the histories single vs multiple siblings with autism were not confirmed, with the exception of increased viral-type illness during gestation in single-incidence cases. Thus, the etiology of the brain pathology that characteristically disrupts normal development and produces the syndrome of autism remains obscure. Other data from the epidemiologic survey, however, suggest that the role of genetic factors needs to be explored further.

The UCLA-University of Utah epidemiologic survey of autism: genealogical analysis of familial aggregation

To assess familial aggregation of autism, 86 autistic subjects were linked to the Utah Genealogical Database. Kinship coefficients were estimated for all possible pairs of autistic subjects and then averaged. Fifty replicate sets of matched control subjects (86 members in each set) were drawn randomly from the database, and the average kinship coefficient was computed for all possible pairs of individuals in each set. The average kinship coefficient for the autistic subjects was approximately 1/1,000, while the average kinship coefficients for the 50 control groups ranged from 4/100,000 to 1.6./10,000. These results indicate a strong tendency for autism to cluster in families. When kinship was analyzed by specific degrees of relationship, it was shown that the familial aggregation of autism is confined exclusively to sib pairs and does not extend to more remote degrees of relationship. This finding indicates that a single-gene model is unlikely to account for most cases of autism.

The UCLA-University of Utah epidemiologic survey of autism: recurrence risk estimates and genetic counseling

The authors recently reported, in this journal, an epidemiologic survey of autism in Utah. Twenty (9.7%) of the 207 families ascertained had more than one autistic child. Analyses of these data revealed that autism is 215 times more frequent among the siblings of autistic patients than in the general population. The overall recurrence risk estimate (the chance that each sibling born after an autistic child will develop autism) is 8.6%. If the first autistic child is a male the recurrence risk estimate is 7%, and if a female 14.5%. These new recurrence risk estimates should be made available to all individuals who have autistic children and are interested in family planning.

A magnetic resonance imaging study of autism: normal fourth ventricle size and absence of pathology

Magnetic resonance imaging did not diagnose neuropathology in 15 autistic patients. Measurements of the midsagittal area and volume of the fourth ventricle did not differ between these patients and matched control subjects.

Psychometric assessment of first-degree relatives of 62 autistic probands in Utah

The Wechsler Intelligence Scales, Wide Range Achievement Test, and the Shipley-Hartford Test were administered to 122 parents and 153 siblings of 62 autistic probands in Utah. Scores were distributed as expected within the published normative ranges for each scale. Parents' scores correlated with those of their nonautistic children, but neither parents' nor siblings' scores correlated with the IQ level of the autistic probands. These results do not confirm prior reports from England and the United States of a high rate of cognitive and learning problems in the siblings of autistic individuals, nor the aggregation of such problems in the siblings of probands with high or low levels of cognitive function.

The UCLA-University of Utah epidemiologic survey of autism: prevalence

The authors conducted an epidemiologic survey in Utah using a four-level ascertainment system, blind current diagnostic assessments, and DSM-III criteria. Of 483 individuals ascertained, 241 were diagnosed as having autism. The best estimate for the prevalence rate was 4 per 10,000 population. Autism was not associated with parental education, occupation, racial origin, or religion. Sixty-six percent of the autistic subjects scored below 70 on standardized IQ tests, and females scored proportionately lower than males. Twenty (9.7%) of 207 families had more than one autistic sibling, which supports the authors' previous finding that there may be a familial subtype of autism.

Platelet size, number, and serotonin content in blood of autistic, childhood schizophrenic, and normal children

Platelet volumes were measured in 19 autistic, 26 normal, and 6 schizophrenic children with similar blood serotonin concentrations. The groups did not significantly differ in platelet volumes, nor did platelet volumes and blood serotonin concentrations correlate. These results do not support the hypothesis that the hyperserotoninemia in some autistics reflects increased platelet volume.

Electroretinograms in autism: a pilot study of b-wave amplitudes

The authors recorded electroretinograms for 27 autistic patients and 20 age- and sex-matched healthy volunteers. Thirteen (48%) of the autistic patients demonstrated subnormal b-wave amplitudes, which may indicate abnormal retinal function. One patient was tested serially at two sites; his low b-wave amplitude did not vary over time or between the two sites. If this retinal finding can be confirmed at other laboratories and in larger samples of autistic patients, it might provide a marker for a specific subtype of autism.

Patterns of intellectual functioning in non-retarded autistic and schizophrenic children

The WISC-R factor scores of non-retarded children meeting DSM III criteria for autism and schizophrenia were compared. The scores of the schizophrenic children on factor 3 were significantly lower than those of the autistic children, below the range of normal children, and significantly lower than the scores they obtained on the verbal comprehension and perceptual organization factors. The autistic children scored in the superior range on the block design subtest and did not show gross impairments in language function as indexed by scores on the verbal comprehension factor. The only subtest autistic children were impaired on was the comprehension subtest.