Neurocognitive mechanisms of co-occurring math difficulties in dyslexia: Differences in executive function and visuospatial processing

Children with dyslexia frequently also struggle with math. However, studies of reading disability (RD) rarely assess math skill, and the neurocognitive mechanisms underlying co-occurring reading and math disability (RD+MD) are not clear. The current study aimed to identify behavioral and neurocognitive factors associated with co-occurring MD among 86 children with RD. Within this sample, 43% had co-occurring RD+MD and 22% demonstrated a possible vulnerability in math, while 35% had no math difficulties (RD-Only). We investigated whether RD-Only and RD+MD students differed behaviorally in their phonological awareness, reading skills, or executive functions, as well as in the brain mechanisms underlying word reading and visuospatial working memory using functional magnetic resonance imaging (fMRI). The RD+MD group did not differ from RD-Only on behavioral or brain measures of phonological awareness related to speech or print. However, the RD+MD group demonstrated significantly worse working memory and processing speed performance than the RD-Only group. The RD+MD group also exhibited reduced brain activations for visuospatial working memory relative to RD-Only. Exploratory brain-behavior correlations along a broad spectrum of math ability revealed that stronger math skills were associated with greater activation in bilateral visual cortex. These converging neuro-behavioral findings suggest that poor executive functions in general, including differences in visuospatial working memory, are specifically associated with co-occurring MD in the context of RD. RESEARCH HIGHLIGHTS: Children with reading disabilities (RD) frequently have a co-occurring math disability (MD), but the mechanisms behind this high comorbidity are not well understood. We examined differences in phonological awareness, reading skills, and executive function between children with RD only versus co-occurring RD+MD using behavioral and fMRI measures. Children with RD only versus RD+MD did not differ in their phonological processing, either behaviorally or in the brain. RD+MD was associated with additional behavioral difficulties in working memory, and reduced visual cortex activation during a visuospatial working memory task.

Brain bases of morphological awareness and longitudinal word reading outcomes

Children's spoken language skills are essential to the development of the "reading brain," or the neurocognitive systems that underlie successful literacy. Morphological awareness, or sensitivity to the smallest units of meaning, is a language skill that facilitates fluent recognition of meaning in print. Yet despite the growing evidence that morphology is integral to literacy success, associations among morphological awareness, literacy acquisition, and brain development remain largely unexplored. To address this gap, we conducted a longitudinal investigation with 75 elementary school children (5-11 years of age) who completed an auditory morphological awareness neuroimaging task at Time 1 as well as literacy assessments at both Time 1 and Time 2 (1.5 years later). Findings reveal longitudinal brain-behavior associations between morphological processing at Time 1 and reading outcomes at Time 2. First, activation in superior temporal brain regions involved in word segmentation was associated with both future reading skill and steeper reading gains over time. Second, a wider array of brain regions across the language network were associated with polymorphemic word reading as compared with broader word reading skill (reading both simple and complex words). Together, these findings reinforce the importance of word segmentation skills in learning to read and highlight the importance of considering complex word reading skills in building comprehensive neurocognitive models of literacy. This study fills a gap in our knowledge of how processing meaningful units in speech may help to explain differences in children's reading development over time and informs ongoing theoretical questions about the role of morphology in learning to read.

Phonological and morphological literacy skills in English and Chinese: A cross-linguistic neuroimaging comparison of Chinese-English bilingual and monolingual English children

Over the course of literacy development, children learn to recognize word sounds and meanings in print. Yet, they do so differently across alphabetic and character-based orthographies such as English and Chinese. To uncover cross-linguistic influences on children's literacy, we asked young Chinese-English simultaneous bilinguals and English monolinguals (N = 119, ages 5-10) to complete phonological and morphological awareness (MA) literacy tasks. Children completed the tasks in the auditory modality in each of their languages during functional near-infrared spectroscopy neuroimaging. Cross-linguistically, comparisons between bilinguals' two languages revealed that the task that was more central to reading in a given orthography, such as phonological awareness (PA) in English and MA in Chinese, elicited less activation in the left inferior frontal and parietal regions. Group comparisons between bilinguals and monolinguals in English, their shared language of academic instruction, revealed that the left inferior frontal was less active during phonology but more active during morphology in bilinguals relative to monolinguals. MA skills are generally considered to have greater language specificity than PA skills. Bilingual literacy training in a skill that is maximally similar across languages, such as PA, may therefore yield greater automaticity for this skill, as reflected in the lower activation in bilinguals relative to monolinguals. This interpretation is supported by negative correlations between proficiency and brain activation. Together, these findings suggest that both the structural characteristics and literacy experiences with a given language can exert specific influences on bilingual and monolingual children's emerging brain networks for learning to read.

Sources of Heterogeneity in Functional Connectivity During English Word Processing in Bilingual and Monolingual Children

Diversity and variation in language experiences, such as bilingualism, contribute to heterogeneity in children's neural organization for language and brain development. To uncover sources of such heterogeneity in children's neural language networks, the present study examined the effects of bilingual proficiency on children's neural organization for language function. To do so, we took an innovative person-specific analytical approach to investigate young Chinese-English and Spanish-English bilingual learners of structurally distinct languages. Bilingual and English monolingual children (N = 152, M(SD)_age = 7.71(1.32)) completed an English word recognition task during functional near-infrared spectroscopy neuroimaging, along with language and literacy tasks in each of their languages. Two key findings emerged. First, bilinguals' heritage language proficiency (Chinese or Spanish) made a unique contribution to children's language network density. Second, the findings reveal common and unique patterns in children's patterns of task-related functional connectivity. Common across all participants were short-distance neural connections within left hemisphere regions associated with semantic processes (within middle temporal and frontal regions). Unique to more proficient language users were additional long-distance connections between frontal, temporal, and bilateral regions within the broader language network. The study informs neurodevelopmental theories of language by revealing the effects of heterogeneity in language proficiency and experiences on the structure and quality of emerging language neural networks in linguistically diverse learners.

Morphological awareness and its role in early word reading in English monolinguals, Spanish-English, and Chinese-English simultaneous bilinguals

Words' morphemic structure and their orthographic representations vary across languages. How do bilingual experiences with structurally distinct languages influence children's morphological processes for word reading? Focusing on English literacy in monolinguals and bilinguals (N = 350, ages 5-9), we first revealed unique contributions of derivational ( friend-li-est) and compound (girl-friend) morphology to early word reading. We then examined mechanisms of bilingual transfer in matched samples of Spanish-English and Chinese-English dual first language learners. Results revealed a principled cross-linguistic interaction between language group (Spanish vs. Chinese bilinguals) and type of morphological awareness. Specifically, bilinguals' proficiency with the type of morphology that was less characteristic of their home language explained greater variance in their English literacy. These findings showcase the powerful effects of bilingualism on word reading processes in children who have similar reading proficiency but different language experiences, thereby advancing theoretical perspectives on literacy across diverse learners.

Language combinations of multilinguals are reflected in their first-language knowledge and processing

Consequences of multilingualism vary from offering cognitive benefits to poor educational and cognitive outcomes. One aspect of multilingualism that has not been systematically examined is the typology of multilinguals' languages: Do differences and similarities between languages multilinguals are exposed to contribute to the development of their cognition and brain? We investigated n = 162 5-6-year-olds with various language backgrounds on a monolingual-to-quintilingual continuum. Our results show that typological linguistic diversity can be related to expressive vocabulary knowledge in the dominant language. On neural level, it relates to brain activation patterns in (among others) the PGa area in the bilateral IPL, a brain region previously associated with multilingual experience, but never with language typology. We propose an ecologically valid way of describing the continuum of multilingual language experience and provide evidence for both the cognition and the brain of multilingual kindergartners to be related to the typological linguistic diversity of their environment.

Brain bases of English morphological processing: A comparison between Chinese-English, Spanish-English bilingual, and English monolingual children

How do early bilingual experiences influence children's neural architecture for word processing? Dual language acquisition can yield common influences that may be shared across different bilingual groups, as well as language-specific influences stemming from a given language pairing. To investigate these effects, we examined bilingual English speakers of Chinese or Spanish, and English monolinguals, all raised in the US (N = 152, ages 5-10). Children completed an English morphological word processing task during fNIRS neuroimaging. The findings revealed both language-specific and shared bilingual effects. The language-specific effects were that Chinese and Spanish bilinguals showed principled differences in their neural organization for English lexical morphology. The common bilingual effects shared by the two groups were that in both bilingual groups, increased home language proficiency was associated with stronger left superior temporal gyrus (STG) activation when processing the English word structures that are most dissimilar from the home language. The findings inform theories of language and brain development during the key periods of neural reorganization for learning to read by illuminating experience-based plasticity in linguistically diverse learners.

Impacts of the COVID-19 disruption on the language and literacy development of monolingual and heritage bilingual children in the United States

Children who speak one language at home and a different language at school may be at higher risk of falling behind in their academic achievement when schooling is disrupted. The present study examined the effects of COVID-19-related school disruptions on English language and literacy development among monolingual and bilingual children in the US. All children attended English-only schools that implemented varied forms of virtual and hybrid schooling during the pandemic. Pre-COVID-19 and during-COVID-19 examinations were conducted with 237 children (M(SD) _age  = 7.78 (1.54) at Time 1) from relatively high SES homes, including 95 monolinguals, 75 Spanish-English and 67 Chinese-English bilinguals. The findings revealed different impacts of COVID-19 school disruptions on the present bilingual and monolingual participants. Specifically, between Time 1 and Time 2, monolingual children made age-appropriate improvements in all literacy measurements. Relative to monolinguals, both bilingual groups showed greater gains in vocabulary but lower gains in reading comprehension. Moreover, across groups, children's independent reading practices during COVID-19 were positively associated with children's literacy growth during the pandemic-related schooling disruptions. Taken together, these findings inform theoretical perspectives on learning to read in linguistically diverse children experiencing COVID-19-related schooling disruptions.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11145-022-10388-x.

Risk and resilience correlates of reading among adolescents with language-based learning disabilities during COVID-19

Students with language-based learning disabilities (LBLD) can face elevated socio-emotional well-being challenges in addition to literacy challenges. We examined the prevalence of risk and resilience factors among adolescents with LBLD (N = 93), ages 16-18, and the association with reading performance during the COVID-19 pandemic. Data were collected at the start and end of the first fully remote academic year of COVID-19 (2020-2021). Participants completed standardized word and text reading measures, as well as self-report surveys of executive functions (EF), and socio-emotional skills associated with resilience (grit, growth mindset, self-management, self-efficacy, and social awareness) or risk (anxiety, depression, COVID-19 related PTSD, and perceived COVID-19 impact). Survey data at the start of the school year (Time 1) captured three underlying factors associated with socioemotional risk, socioemotional resilience, and regulation (i.e., EF). Path analyses revealed that students' Time 2 oral reading scores were significantly and uniquely predicted by socioemotional resilience, even when controlling for word-level reading at Time 1. Socioemotional risk, EF, and perceived COVID-19 impact were not directly related to Time 2 oral reading scores; however, students' resilience mediated the associations between risk and reading outcomes. These results demonstrate that adolescents' mental health concerns, self-regulatory ability, and socioemotional resilience were all associated with their experiences of the COVID-19-related stress. However, despite the high-risk context of the pandemic, and socio-emotional challenges faced by students with LBLD, our findings indicate that resilience directly predicts end-of-year reading outcomes and mediates the impact of socioemotional risk on achievement.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11145-022-10361-8.

Functional mapping and cooperation between the cerebellum and cerebrum during word reading

Multiple areas in the cerebellum have been reported to be engaged in reading. However, how these regions cooperate with the reading-related areas in the cerebrum remains unclear. Here, brain images of fifty-two adults were acquired via functional magnetic resonance imaging. By comparing the cerebellar activation across three localization tasks targeting orthographic, phonological, and semantic processing, we first identified three different reading-related areas in the cerebellum, biased toward orthography, phonology, and semantics, respectively. Then, functional connectivity (FC) analyses demonstrated that the mean FC between functionally corresponding areas across the cerebrum and cerebellum was greater than that between noncorresponding areas during silent word reading. FC patterns of functionally corresponding areas could significantly predict reading speed, with the FC driven from orthographic and semantic areas contributing the most. Effective FC analyses further showed that orthographic and semantic areas in the cerebellum had selective and direct connectivity to areas in the cerebrum with similar functional specificity. These results suggest that reading-related areas vary in their functions to reading, and cooperation between areas with corresponding functions was greater than that between noncorresponding areas. These findings emphasize the importance of functional cooperation between the cerebrum and cerebellum during reading from a new perspective.

The neurocognitive basis of morphological processing in typical and impaired readers

Morphological awareness, or sensitivity to units of meaning, is an essential component of reading comprehension development. Current neurobiological models of reading and dyslexia have largely been built upon phonological processing models, yet reading for meaning is as essential as reading for sound. To fill this gap, the present study explores the relation between children's neural organization for morphological awareness and successful reading comprehension in typically developing and impaired readers. English-speaking children ages 6-11 (N = 97; mean age = 8.6 years, 25% reading impaired) completed standard literacy assessments as well as an auditory morphological awareness task during functional near-infrared spectroscopy (fNIRS) neuroimaging, which included root (e.g., PERSON + al) and derivational (e.g., quick + LY) morphology. Regression analyses revealed that children's morphological awareness predicted unique variance in reading comprehension above and beyond demographic factors, vocabulary knowledge, and decoding ability. Neuroimaging analyses further revealed that children with stronger reading comprehension showed greater engagement of brain regions associated with integrating sound and meaning, including left inferior frontal, middle temporal, and inferior parietal regions. This effect was especially notable for the derivational morphology condition that involved manipulating more analytically demanding and semantically abstract units (e.g., un-, -ly, -ion). Together, these findings suggest that successful reading comprehension, and its deficit in dyslexia, may be related to the ability to manipulate morpho-phonological units of word meaning and structure. These results inform theoretical perspectives on literacy and children's neural architecture for learning to read.

Contributions of bilingual home environment and language proficiency on children's Spanish-English reading outcomes

This study examines the influence of language environment on language and reading skills and the cross-linguistic contributions to reading outcomes in 132 Spanish-English bilingual children ages 7-12 (52% female; 98% Hispanic). We present three major findings: children's language knowledge is separable into general (e.g., phonological awareness) and language-specific (e.g., meaning, grammar) skills; regular Spanish use positively relates to children's Spanish language and reading skills and does not limit English skills; and Spanish reading comprehension is positively associated with English reading comprehension. The model explains a significant percentage of the variance in English (R²  = .89) and Spanish (R²  = .87) reading comprehension outcomes. Findings shed light on the interdependence of Spanish and English as they relate to bilingual reading acquisition.

Cross-linguistic differences in the associations between morphological awareness and reading in Spanish and English in young simultaneous bilinguals

This study aimed to clarify the relations between morphological awareness and literacy skills in Spanish and English in young simultaneous bilingual learners. Guided by theoretical perspectives on the associations between morphological awareness and word- versus sentence-level literacy skills, and their transfer between bilinguals' two languages, we asked bilingual children (N = 90; M = 8.07 years old) to complete dual-language literacy assessments. First, we observed cross-linguistic differences in the associations between morphology and reading. In English, morphological awareness was directly related to word reading and reading comprehension, whereas in Spanish, the association with reading comprehension was fully mediated by vocabulary and single word reading. Second, we observed cross-linguistic associations from English word reading to Spanish reading comprehension, and from Spanish reading comprehension to English reading comprehension. Our findings inform bilingual literacy theory by revealing both cross-linguistic differences and bidirectional associations between literacy skills across typologically-distinct orthographies. In particular, children's word-level skills transferred from the language of schooling (English) into their heritage language (Spanish), and their broader reading comprehension skills transferred from the heritage language to support English. Taken together, these findings support the value of bilingual heritage language maintenance for reading achievement in children's dominant language of literacy instruction.

Decoding the role of the cerebellum in the early stages of reading acquisition

Numerous studies have consistently reported functional activation of the cerebellum during reading tasks, especially in the right cerebellar hemisphere. However, it remains unclear whether this region is also involved in reading during the earliest stages of reading acquisition. Here, we investigated whether and how the cerebellum contributes to reading acquisition. We tested 80 5-6-year-old kindergarteners, who performed a visual word matching task during which functional MRI (fMRI) data were collected. We found that bilateral cerebellar hemispheres were significantly activated during visual word processing. Moreover, activation of left cerebellar lobule VII extending to lobule VIII negatively and significantly correlated with current reading ability, whereas activation of right cerebellar lobule VII extending to lobule VIII significantly and positively correlated with future reading ability. Functional decoding via functional connectivity patterns further revealed that left and right cerebellar lobules connected with different cerebral cortex regions. Our results suggest a division of labor between the left and right cerebellar lobules in beginning readers.

Morphological processing in Chinese engages left temporal regions

Morphological awareness, the ability to manipulate the smallest units of meaning, is critical for Chinese literacy. This is because Chinese characters typically reflect the morphemic, or morpho-syllabic units of language. Yet, the neurocognitive mechanisms underlying Chinese speakers' morphological processing remain understudied. Proficient readers (N = 14) completed morphological and phonological judgment tasks in Chinese, in both auditory and visual modalities, during fMRI imaging. Key to our inquiry were patterns of activation in left temporal regions, especially the superior temporal gyrus, which is critical for phonological processing and reading success. The findings revealed that morphological tasks elicited robust activation in superior and middle temporal regions commonly associated with automated phonological and lexico-semantic analyses. In contrast, the rhyme judgment task elicited greater activation in left frontal lobe regions, reflecting the analytical complexity of sound-to-print mapping in Chinese. The findings suggest that left temporal regions are sensitive to salient morpho-syllabic characteristics of a given language.

Spoken language proficiency predicts print-speech convergence in beginning readers

Learning to read transforms the brain, building on children's existing capacities for language and visuospatial processing. In particular, the development of print-speech convergence, or the spatial overlap of neural regions necessary for both auditory and visual language processing, is critical for literacy acquisition. Print-speech convergence is a universal signature of proficient reading, yet the antecedents of this convergence remain unknown. Here we examine the relationship between spoken language proficiency and the emergence of the print-speech network in beginning readers (ages 5-6). Results demonstrate that children's language proficiency, but not their early literacy skill, explains variance in their print-speech neural convergence in kindergarten. Furthermore, print-speech convergence in kindergarten predicts reading abilities one year later. These findings suggest that children's language ability is a core mechanism guiding the neural plasticity for learning to read, and extend theoretical perspectives on language and literacy acquisition across the lifespan.

Epidermal growth factor receptor (EGFR) expression in prostatic adenocarcinoma after hormonal therapy: a fluorescence in situ hybridization and immunohistochemical analysis

BACKGROUND

The progression of normal prostatic epithelium to androgen-dependent cancer and, eventually, hormone-refractory prostate cancer is a complex process involving many different growth regulatory signals. Activation of epidermal growth factor receptor (EGFR) has been implicated in prostate cancer cell growth.

METHODS

This study was undertaken to investigate both amplification of EGFR gene by fluorescence in situ hybridization (FISH) and over-expression of EGFR by immunohistochemical staining in prostate tissue from 71 patients treated by hormonal therapy.

RESULTS

EGFR gene amplification was present in 1 of 71 tumors, and polysomy of chromosome 7 was present in 24 of 71 tumors. Immunohistochemically, EGFR expression was demonstrable in 57 of 71 tumors. Membranous immunostaining for EGFR was observed in >75% of tumor cells in 11% of cases, in 51-75% of tumor cells in 20% of cases, in 26-50% of tumor cells in 21% of cases, in 11-25% of tumor cells in 21% of cases, and in 1-10% of tumor cells in 7% of cases. No immunostaining for EGFR was seen in 20% of cases. There was no correlation between EGFR protein expression and gene amplification. There was also no correlation between EGFR expression and clinicopathological characteristics or clinical outcome.

CONCLUSIONS

We found that EGFR gene expression was detectable in 35% of this large series of hormone-treated prostate cancer, and that EGFR protein is frequently expressed in tissue from these patients. EGFR over-expression may serve as a reasonable target for therapeutic intervention in this otherwise difficult to treat subset of prostate cancer.

Loss of heterozygosity identifies genetic changes in chronic myeloid disorders, including myeloproliferative disorders, myelodysplastic syndromes and chronic myelomonocytic leukemia

This study evaluates changes in genetic loci of chronic myeloid disorders using loss of heterozygosity (LOH) techniques. We present the combined results of three experiments. First, examination of a panel of genetic loci in groups of myeloproliferative disorders was evaluated. The second experiment involved microdissection of megakaryocytes from myeloproliferative disorders and comparison of their genetic changes to surrounding neoplastic marrow elements. Finally, we compared results of LOH studies of myeloproliferative disorders to those of myelodysplastic syndromes and chronic myelomonocytic leukemia. A total of 41 bone marrow biopsies were evaluated. Twenty-seven were myeloproliferative disorders (11 chronic idiopathic myelofibrosis, 11 essential thrombocythemia, 5 polycythemia vera). The remaining cases consisted of myelodysplastic syndromes (total=5; RAEB-1=2; RAEB-2=2; MDS, not otherwise specified=1) and chronic myelomonocytic leukemia (n=8). The abnormalities in myeloproliferative disorders were distributed as follows: D7S2554-4/14 (5/14); D8S263-4/15 (5/15); D9S157-5/15 (5/15); D9S161-7/17 (6/17); D13S319-5/14 (4/14); TP53-5/16 (5/16); D20S108-4/15 (4/15). In 75% cases diagnosed as essential thrombocythemia (6/8), both cases of polycythemia vera (2/2), and 29% cases of chronic idiopathic myelofibrosis (2/7), there were genetic differences between the megakaryocytes and the surrounding marrow. These results suggest that in some cases, megakaryocytes have different clonal abnormalities than surrounding hematopoietic tissue. The genetic profiles of myeloproliferative disorders had several differences from those of myelodysplastic syndromes. Although different from both, chronic myelomonocytic leukemia appeared more similar to myeloproliferative disorders using these techniques.

The relationship between the extent of surgical margin positivity and prostate specific antigen recurrence in radical prostatectomy specimens

The presence of positive surgical margins is a negative prognostic indicator in patients undergoing prostatectomy for prostate cancer; whether the extent of the positive margins affects the clinical outcome with regards to prostate-specific antigen (PSA) recurrence remains uncertain. We evaluated the linear extent of margin positivity as a prognostic indicator in a series of radical prostatectomy specimens. One hundred seventy-four consecutive margin-positive prostatectomy specimens were evaluated. The linear extent of margin positivity was measured with an ocular micrometer and ranged from 0.05 to 75.0 mm (mean, 8.94; median, 5.0). The linear extent of margin positivity was associated with tumor volume (P = .03) but was not associated with patients' age at surgery, preoperative PSA level, prostate weight, pathologic stage, Gleason score, extraprostatic extension, seminal vesicle invasion, perineural invasion, high-grade prostatic intraepithelial neoplasia, or PSA recurrence. In the full model multiple Cox regression, significant predictors for PSA recurrence were Gleason score (P = .001) and preoperative PSA (P = .01); extent of margin positivity was not predictive of PSA recurrence (hazard ratio, 1.00; 95% confidence interval, 0.98-1.02; P = .97) nor was tumor volume a significant factor when adjusted for other covariates (P = .27). Preoperative PSA, tumor stage, and Gleason score remained significant prognostic factors in evaluating the likelihood of PSA recurrence in patients with positive surgical margins; the extent of margin positivity, however, is not a prognostic factor for PSA recurrence and should, therefore, not necessarily be included in the final report for radical prostatectomy specimens.

Positive-block ratio in radical prostatectomy specimens is an independent predictor of prostate-specific antigen recurrence

Tumor volume has been considered an important variable in determining the probability of prostate-specific antigen (PSA) recurrence in prostatic adenocarcinoma. There have been many studies that have tried to determine an appropriate method of calculating tumor volume, but no single methodology has been agreed upon. We tested the hypothesis that the ratio of tumor positive tissue blocks to the total number of blocks submitted (positive-block ratio) can be used as an independent prognostic indicator for PSA recurrence. We analyzed 504 patients who underwent total radical retropubic prostatectomy between 1990 and 1998. None of the patients had preoperative radiation or androgen-deprivation therapy. Clinical records were reviewed. The mean positive-block ratio was 0.44 (median, 0.43; range, 0.05 to 1.0). The positive block-ratio was significantly associated with Gleason score, pathologic stage, surgical margin status, extraprostatic extension, seminal vesical invasion, lymph node metastasis, perineural invasion, and preoperative serum PSA level (all P<0.001). Using a multivariate Cox regression model, controlling for pathologic stage, Gleason score, lymph node metastasis, and surgical margin status, positive-block ratio was an independent predictor of PSA recurrence (hazard ratio, 2.3; 95% confidence interval, 1.06-4.83; P=0.03). Five-year PSA recurrence-free survival was 67% for those patients with positive-block ratio <or=0.43, as compared with 42% those with positive-block ratio >0.43 (P<0.001). Positive-block ratio is an independent predictor of PSA recurrence and this simple method of tumor measurement seems to be promising for quantifying tumor volume if our findings are validated by subsequent reports.

Nonoperative treatments for sciatica: a pilot study for a randomized clinical trial

OBJECTIVES

To assess the feasibility of patient recruitment, the ability of patients and clinicians to comply with study protocols, and the use of data collection instruments to collect cost-effectiveness data, and to obtain variability estimates for sample-size calculations for a full-scale trial.

STUDY DESIGN

Prospective, observer-blinded, pilot randomized clinical trial.

SETTING

Primary contact chiropractic and medical clinics.

PATIENTS

Ages 20 to 65 years, with low back-related radiating leg pain (sciatica).

OUTCOME MEASURES

Self-report questionnaires were administered at baseline and 3 and 12 weeks after randomization. The measures included leg and back pain severity, frequency and bothersomeness of symptoms, leg/back disability, medication use, global improvement, satisfaction, and health care utilization.

INTERVENTIONS

Medical care, chiropractic care, and epidural steroid injections.

RESULTS

A total of 706 persons were screened by phone to determine initial eligibility. Of these, over 90% of those persons contacted did not meet the entrance criteria. The most common reason for disqualification was that the duration of the complaint was longer than 3 months. Twenty patients were randomized into the study. All 3 groups showed substantial improvements in the main patient-rated outcomes at the end of the 12-week intervention phase. For leg pain, back pain, frequency and bothersomeness of leg symptoms, and Roland-Morris disability score, the percent improvement varied from 50% to 84%, and the corresponding effect sizes ranged from 0.8 to 2.2. Bothersomeness of leg symptoms was the most responsive outcome associated with the largest magnitude of effect size. All within-group changes from baseline were statistically significant (P <.01). No between-group comparisons were planned or performed because of the insufficient sample size and high risk of committing type I and type II errors.

CONCLUSIONS

Pilot studies such as these are important for the determination of the feasibility of conducting costly, larger scale trials. Recruitment for a full-scale study of sciatica of 2 to 12 weeks duration is not feasible, given the methods used in this pilot study. Our results do indicate, however, that there are substantial numbers of patients with sciatica more chronic in nature who would be interested in participating in a similar study. In addition, collaboration with a local health maintenance organization would likely facilitate clinician referrals and optimize the recruitment process. Patient and provider compliance was high in the pilot study, which indicates that most study protocols are feasible. Additionally, we were able to collect complete outcomes data, including those regarding health care use. A suggested modification by investigators and outside consultants has resulted in the replacement of the medication group with a minimal intervention control group (ie, self-care advice). As a result, a second pilot study of patients with sciatica of more than 4 weeks duration has been planned before a full-scale trial is attempted.

Transcutaneous lumbar diskectomy for internal disk derangement: a new indication

BACKGROUND

Percutaneous diskectomy has been used effectively to treat lumbar disk herniation. The purpose of this review was to determine whether transcutaneous diskectomy is an effective surgical option for treating lumbar internal disk derangement.

METHODS

Comprehensive retrospective review via personal interview included 103 consecutive patients available for long-term follow-up. For determining results as excellent, good, fair, or poor, the criteria included subjective relief of back and/or leg pain, ability to perform preinjury job functions, residual physical restrictions, use of medications, and need for subsequent surgery. Factors affecting results were statistically analyzed.

RESULTS

The overall success rate was 83%, with no statistically significant differences in results based on sex, workers' compensation status, or levels of diskectomy.

CONCLUSIONS

The favorable results from this series illustrate the high success rate of transcutaneous lumbar diskectomy in a heterogeneous patient population. Coupling the rate of success with a low rate of complications, transcutaneous lumbar diskectomy appears to be an effective, minimally invasive treatment for internal disk derangement.

Spine fusion for discogenic low back pain: outcomes in patients treated with or without pulsed electromagnetic field stimulation

Sixty-one randomly selected patients who underwent lumbar fusion surgeries for discogenic low back pain between 1987 and 1994 were retrospectively studied. All patients had failed to respond to preoperative conservative treatments. Forty-two patients received adjunctive therapy with pulsed electromagnetic field (PEMF) stimulation, and 19 patients received no electrical stimulation of any kind. Average follow-up time was 15.6 months postoperatively. Fusion succeeded in 97.6% of the PEMF group and in 52.6% of the unstimulated group (P < .001). The observed agreement between clinical and radiographic outcome was 75%. The use of PEMF stimulation enhances bony bridging in lumbar spinal fusions. Successful fusion underlies a good clinical outcome in patients with discogenic low back pain.

Analgesic effect of bupivacaine on extraperitoneal laparoscopic hernia repair

Local anesthetics decrease postoperative pain when placed at the surgical site. Patients benefit from laparoscopic extraperitoneal hernia repair because this allows earlier mobilization than the more classical open surgical approach. The purpose of this study was to determine the pain-sparing efficacy of local anesthetics placed in the preperitoneal fascial plane during extraperitoneal laparoscopic inguinal hernia surgery. Forty-two outpatients were included in a double-blind, randomized, placebo-controlled, institutional review board-approved study. At the conclusion of a standardized general anesthetic, 21 patients received 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane before incisional closure, whereas the other 21 patients received 60 mL of the isotonic sodium chloride solution placebo. Postoperative pain was assessed 1, 4, 8, 24, and 72 h postoperatively. In addition, postoperative fentanyl and outpatient acetaminophen 500 mg/hydrocodone 5 mg requirements were recorded. All hernia repairs were performed by the same surgeon. Appropriate statistical analyses were used. There were no significant differences between the bupivacaine and isotonic sodium chloride solution groups with regard to postoperative pain scores, length of postanesthesia care unit stay, or analgesic requirements. Furthermore, neither unilateral versus bilateral repair nor operative time affected the measured parameters. The addition of 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane during extraperitoneal laparoscopic hernia repair did not significantly alter pain scores, supplementary analgesic requirements, or recovery room length of stay.

IMPLICATIONS

The placement of 60 mL of 0.125% bupivacaine into the preperitoneal fascial plane during extraperitoneal laparoscopic hernia repair did not significantly alter pain scores, supplementary analgesic requirements, or recovery room length of stay.

Gastric and hepatic infarction following embolization of the left gastric artery: case report

The authors report an initially successful left gastric artery embolization performed because of massive upper gastrointestinal bleeding; the procedure was complicated by focal gastric and hepatic infarctions. These complications occurred in the absence of underlying factors known to predispose to ischemia. Low-grade gastric bleeding persisting after seemingly successful embolization of the left gastric artery may indicate ischemic gastritis and is an indication for endoscopy. In addition, the presence of a left hepatic artery completely replaced to the left gastric artery should alert one to the potential for hepatic necrosis.

Primary squamous-cell carcinoma of the breast. Diagnosis by fine needle aspiration cytology

A primary squamous-cell carcinoma of the breast was evaluated by fine needle aspiration cytology in a 41-year-old female. The subsequent mastectomy specimen contained a well-differentiated keratinizing squamous-cell carcinoma. On electron microscopic evaluation, the tumor cells contained well-formed desmosomes and prominent bundles of tonofilaments, typical of squamous-cell carcinoma in other organs. Thorough evaluation of the patient did not reveal squamous-cell carcinoma elsewhere.

Diagnosis of isolated perforation of the gallbladder following blunt trauma using sonography and CT scan

Perforation of the gallbladder from blunt abdominal trauma is relatively rare, and is usually diagnosed at laparotomy for associated visceral injury. Isolated injury of the gallbladder may be unrecognized leading to delayed diagnosis and its associated increased morbidity. Computerized tomography, sonography, and HIDA Tc99m may be used in the early diagnosis of the acutely perforated gallbladder.

Seasat visible and infrared radiometer

Visual and infrared images produced by the Seasat visible and infrared radiometer (VIRR) are adequate for the identification of cloud, land, and water features. A statistical comparison of VIRR-derived sea-surface temperatures in a cloud-free region with a National Oceanic and Atmospheric Administration analysis based on various surface measurements taken in the same region showed agreement to +/- 1.7 degrees K root-mean-square.

Accuracy of echocardiography in assessing left ventricular dimensions and volume

The accuracy of determining left ventricular function from echocardiography was assessed in 26 children (group I) with cineangiographically-determined normal left ventricular volume (LVV) and 28 children (group II) with large left ventricular volumes. Conventional LV echo dimensions were compared to the cineangiographic LV anterior-posterior minor axis (LVmA) and LVV. Very good correlations were found in group I between LV end-diastolic echo dimensions (LVEDD) and cine LVmA (r = 0.91) and between LVEDD and LV end-diastolic volume (LVEDV) by cine in group I (r = 0.86). In group II correlations were less accurate between LVEDD and diastolic LVmA and between LVEDD and LVEDV. There was poor correlation between the cine and echo percent of shortening (r = 0.41) and velocity of circumferential fiber shortening (VCF) (r = 0.51). This study demonstrates that M-mode echocardiography is a very useful method for determining LV dimensions in children with normal LV volume, but is less accurate in children with left ventricular volume overload or with abnormal septal orientation or postoperative status after ventriculotomy.

Pre and postoperative ventricular function in infants and children with right ventricular volume overload

Hemodynamic and ventricular volume parameters were evaluated in 21 patients (24 studies) with total anomalous pulmonary venous return (TAPVR), 11 patients with secundum atrial septal defect (ASD), and eight patients who had complete correction of TAPVR or ASD. Right and left ventricular (RV and LV) volume parameters were calculated according to Simpson's rule and the area length methods, respectively. In infants with TAPVR, RV end-diastolic volume was larger than normal, but RV ejection fraction was significantly less than normal. LV end-diastolic volume and LV ejection fraction were all less than normal in infants with or without pulmonary hypertension, and the values did not correlate with the cardiorespiratory symptoms. In children with TAPVR or ASD, RV end-diastolic volume and output were higher than normal preoperatively and decreased to normal or near normal values postoperatively. The data suggest that pulmonary venous obstruction and/or RV failure are responsible for cardiorespiratory symptoms in infants with TAPVR and early surgical intervention is recommended in these patients.

The effect of left ventricular pressure or volume overload on ventricular dimension in children. Left ventricular volume determination from one or two ventricular dimensions

The effect of pressure or volume overload on the geometry of the left ventricle (LV) was determined in order to examine the feasibility and accuracy of LV volume determinations from one minor axis or two dimensions (one minor axis and the longest length). The longest length (LL) and minor axis (MA) in both the anteroposterior (AP) view and lateral (LAT) view were determined from the LV cine silhouette in patients with normal LV volume and pressure (group 1), LV pressure (LVP) overload group (LVP greater than 140 mm Hg, group 2), and LV volume overload group (LV end-diastolic volume greater than 124% of normal, group 3). The ratio of the MA to the LL, which represents the spherical configuration of the LV, was less than "normal" in group 2, and higher than "normal" in group 3. In all groups the LV was less spherical at end-systole than at end-diastole. Additionally, the (MA)3 had a different relationship to true LV volume (biplane LV volume) in the three groups and from diastole to systole in each group. Left ventricular volume calculation from one minor axis was associated with a large error. In contrast, left ventricular volume can be accurately determined from two ventricular dimensions using either the anteroposterior or lateral ventricular image (r larger than or equal to 0.97).

Right and left ventricular volume characteristics in children with pulmonary stenosis and intact ventricular septum

Right (RV) and left ventricular (LV) volume variables were calculated in 27 patients with pulmonary stenosis (PS) during routine cardiac catheterization. These included 21 patients with isolated PS (group I) and seven studies in six patients (group II) with PS and right-to-left atrial shunt. Right and left ventricular volumes were calculated according to Simpson's rule and the area length methods respectively. In group I, right ventricular end-diastolic volume (RVEDV) was not different from normal, RVEF (0.70 +/- 0.02) was significantly higher than normal, and right ventricular stroke index (RVSI) (4.36/L/min/M2 +/- 0.23) was normal. The RVEDV/LVEDV ratio was significantly less than normal (P=0.001). Multiple regression analysis indicated that RVEDV (% of normal) decreased with both age and severity of RV outflow obstruction (r=0.77). In group II, RVEDV and RVSI were both less than normal (P less than 0.001), while RVEF was normal. LVEDV in the group was slightly higher than normal (P=0.026) while LVEF was less than normal (P=0.027) and resulted in normal LVSI. The data suggest that RV and LV function in children with isolated PS are normal, and that knowledge of the RV volume variables is not essential for the management of these patients. In contrast, hearts of patients with PS and right-to-left interatrial shunt have evidence that suggest depressed ventricular function, and the quantitation of RV volume may be helpful in the management of these patients.

Effect of reperfusion on myocardial infarct, and the accuracy of estimating infarct size from serum creatine phosphokinase in the dog

This study was designed to determine the effect of coronary reperfusion on (1) myocardial infarct size and (2) the accuracy of previously reported methods for estimation of infarct size serum creatine phosphokinase (CPK) values. Thirty mongrel dogs, chronically prepared, were studied in the awake state, and were divided into four groups according to the period or left circumflex coronary artery (LCCA) occlusion. Group 1: permanent occlusion (24 h) in nine dogs; group 2: 45 min occlusion (eight dogs); group 3: 1 h occlusion (five dogs); and group 4: 3 h occlusion (eight dogs). Serial blood samples were drawn for 24 h following the beginning of occlusion and were used to determine total and isoenzyme levels of CPK, and lactic dehydrogenase isoenzymes. All dogs were sacrified 24 h after the beginning of occlusion and were anatomically examined. The extent of anatomical myocardial infarction was determined and compared with the extent of myocardial infarction as estimated from serial serum CPK values. Total serum CPK increased significantly in all groups and was associated with the appearance of CPK-MB isoenzyme and an increase in LDH1,2 (LDH1 greater than LDH2) in most dogs. Total serum CPK increased within an hour after reperfusion and the mean values in groups 2, 3, and 4 were significantly high (P less than 0.05) than serum CPK values in group 1 in the period from 110 min to 4 after occlusion. These data demonstrate that reperfusion after 45 min to 3 h of coronary occlusion results in an earlier appearance of total serum CPK. The anatomical infarction in group 1 averaged 28% +/- 3% (SEM) of the total heart and was significantly larger than infarct size in all groups with reperfusion. In contrast, estimated infarction calculated from total CPK in group 1 was not significantly different from the reperfused groups. Although there was correlation between estimated and anatomical infarction, the data in each group showed that anatomical infarct size could not be accurately estimated from total serum CPK.

Right ventricular function in children with tetralogy of Fallot before and after aortic-to-pulmonary shunt

Right and left ventricular volume variables were obtained in 43 tetralogy patients undergoing diagnostic cardiac catheterization. The patient population consisted of 25 preoperative patients (group 1) and 18 patients who had undergone aortic-to-pulmonary shunt procedure (group 2). Volumes were calculated from biplane cineangiocardiograms using Simpson's rule method for the right ventricle (RV) and the area-length methods for the left ventricle (LV). In group 1, RV end-diastolic volume (RVEDV) was not different from normal in the total group and averaged 93 +/- 4% (SEM) of normal. In patients with hemoglobin (Hgb) greater than or equal to 16 g%, however, this variable was significantly (P = 0.044) less than normal. Right ventricular ejection fraction was normal and RV systolic index was significantly (P less than 0.001) reduced, averaging 3.35 +/- 0.18 (SEM) L/min/m2. Left ventricular volume variables in this group were not significantly different from RV volume variables. In group 2, RVEDV in patients with Hgb greater than or equal to 16 g% was significantly (P = 0.037) less than normal, but was normal in patients with Hgb less than 16 g%. Right ventricular ejection fraction averaged 0.52 +/- 0.03 in this group and was significantly (P less than 0.001) less than normal. Right ventricular systolic index (RVSI) averaged 3.51 +/- 0.24 L/min/m2 and was significantly (P = 0.009) less than normal. RVSI in patients with Hgb less than 16 g% averaged 3.90 +/- 0.31 and was not different from normal. In contrast, this variable in patients with Hgb greater than or equal to 16 g% averaged 3.21 +/- 0.34 and was significantly (P = 0.005) less than normal. Left ventricular end-diastolic volume (LVEDV) and LV systolic output in group 2 were significantly higher than RVEDV and RV systolic output. Right ventricular and LV ejection fractions in group 2 were not different. The relatively decreased ejection fraction fraction in tetralogy patients, as compared with patients with valvular pulmonic stenosis and similar volumes and pressures, suggests that the decreased ejection fraction was not due to decreased preload or increased afterload and might be due to impaired ventricular function secondary to chronic hypoxia. Early corrective surgery in these patients might reverse this process. However, patients with severe tetralogy who have small ventricular volume and reduced output might benefit from shunt procedure rather than complete correction.

Echocardiographic determination of left atrial volumes in children with congenital heart disease

The feasibility of determining left atrial volumes (LAV) from LA echo dimensions was assessed in 36 children (group I) with normal cineangiographically determined LAV and 16 children (group II) with LAV overload. Conventional LA echo dimensions, obtained within 24 hours of cardiac catheterization, were compared to the angiographic LA anterior-posterior minor axes (LAmA) and LAV. There was excellent correlation betweeh the LA echo dimensions and the LAmA. In all patients, the LA echo less than LAmA, the differences being more pronounced in group II. Good correlations were found between the LAV and the LA echo, and were expressed by the equations LAV = 7.5 LA echo1.8 (r = .85) and LAV = 8.1 LA echo2.1 (r = .86) for groups I and II, respectively. Changes in LA configuration with volume overload were shown to cause a disproportionate increase in LAmA compared to the other LA dimensions and the LA echo dimension, thus necessitating the separate regression equations. Echo LA to aortic ratios were 0.86 +/- 0.11 and 1.21 +/- 0.23 (mean +/- SD) for groups I and II, respectively. This method of estimating LAV can be useful in the management of left-to-right intracardiac shunts and mitral regurgitation in infants and children.