Lesion-symptom mapping is an important method of identifying networks of brain regions critical for functions. However, results might be influenced substantially by the imaging modality and timing of assessment. We tested the hypothesis that brain regions found to be associated with acute language deficits depend on (1) timing of behavioral measurement; (2) imaging sequences utilized to define the “lesion” (structural abnormality only or structural plus perfusion abnormality); and (3) power of the study. We studied 191 individuals with acute left hemisphere stroke with MRI and language testing to identify areas critical for spoken word comprehension. We use the data from this study to examine the potential impact of these three variables on lesion-symptom mapping. We found that only the combination of structural and perfusion imaging within 48 hours of onset identified areas where more abnormal voxels was associated with more severe acute deficits, after controlling for lesion volume and multiple comparisons. The critical area identified with this methodology was the left posterior superior temporal gyrus, consistent with other methods that have identified an important role of this area in spoken word comprehension. Results have implications for interpretation of other lesion-symptom mapping studies, as well as for understanding areas critical for auditory word comprehension in the healthy brain. We propose that lesion-symptom mapping at the acute stage of stroke addresses a different sort of question about brain-behavior relationships than lesion-symptom mapping at the chronic stage, but that timing of behavioral measurement and imaging modalities should be considered in either case.
The objective of this prospective study was to report on the prevalence of hearing impairment in the neonatal unit population. From 15 February 2000 to 15 March 2000 and from 15 February 2001 to 15 May 2001, 401 neonates were screened using transient evoked otoacoustic emissions (TEOAE) followed by second-stage screening of those infants who failed the initial test. Eight (2 per cent) infants failed one ear and 23 (5.74 per cent) infants failed both ears, adding up to 7.74 per cent planned for second-stage screening. Five out of 22 infants who came for the follow up failed the screening, resulting in a prevalence of hearing impairment of 1 per cent (95 per cent confidence interval [95% CI]: 0.0–2.0). Craniofacial malformations, very low birth weight, ototoxic medication, stigmata/syndromes associated with hearing loss and hyperbilirubinaemia at the level of exchange tranfusion were identified to be independent significant risk factors for hearing impairment, while poor Apgar scores and mechanical ventilation of more than five days were not. In conclusion, hearing screening in high-risk neonates revealed a total of 1 per cent with hearing loss. The changes in the risk profile indicate improved perinatal handling in a neonatal population at risk for hearing disorders.
Introduction: Image-guided fine needle aspiration (FNA) of the musculoskeletal system is expensive to perform and repeat, so on-site evaluation of adequacy (OSEA) is increasingly used to ensure an optimal sample. Metastatic disease to the musculoskeletal system is not uncommon and often requires OSEA when sampled. At large academic centers, cytotechnologists have filled the increased demand for OSEA. However, the performance of cytotechnologists has not been compared with that of cytopathologists for OSEA in FNA of metastatic disease involving bone and soft tissue. Methods: We retrospectively analyzed 10 years of data in which both cytotechnologists and cytopathologists performed OSEA for 1,995 FNAs of bone and soft tissue sites in which metastatic malignancy was suspected or found. We calculated adequacy and accuracy statistics in conjunction with other variables including imaging modality, biopsy site, accompanying core biopsy, tissue type, final diagnosis, and number of smears. Results: A total of 1,995 aspirates of metastatic disease carcinoma, melanoma or lymphoma to bone or soft tissue had OSEA performed by cytotechnologists (681, 33.7%) or cytopathologists (1,314, 66.3%). The adequacy downgrade rate was statistically equivalent (4.1 vs. 3.6%; p = 0.64). Conclusion: Cytotechnologists and cytopathologists perform with reasonable equivalence at OSEA of aspirates from metastatic carcinoma, melanoma or lymphoma involving bone or soft tissue.
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