Impact of childhood epilepsy on reading and phonological processing abilities.

Although children with epilepsy tend to exhibit more reading difficulties than their classmates, no systematic studies have investigated the relationship between these difficulties and epilepsy. As functional neuroimaging studies have implicated both temporal and frontal lobes in the phonological aspect of reading [K.R. Pugh, B.A. Shaywitz, S.E. Shaywitz, et al. Brain 1996;119:1221-38], seizure activity originating in either region could interfere with phonological processing, whereas generalized seizures would not disturb this function as much. To explore this hypothesis, we compared the metaphonological skills of school-aged children with either temporal lobe epilepsy (TLE), frontal lobe epilepsy (FLE), or generalized absence seizures (ABS) with those of healthy controls. While the reading ability of all epileptic children was close to 2 years behind expectations, children with TLE did not differ from the controls on phonological tasks. In contrast, children with FLE exhibited significant deficits, whereas children with ABS showed difficulties restricted to phonemic segmentation. The results suggest that FLE and, to a lesser extent, generalized seizures may interfere with phonological processing, whereas TLE may affect other aspects of reading.

Impact of temporal lobe epilepsy on phonological processing and reading: a case study of identical twins.

In order to evaluate the possible consequences of temporal lobe epilepsy on reading acquisition, we first compared the reading skills and phonological awareness abilities in a set of 13-year-old identical twins, one of whom is affected by temporal lobe epilepsy (LB). We then compared their performances to those of an age- and IQ-matched control group. Both siblings have an intellectual quotient above average as well as normal memory and linguistic abilities. Results showed that the reading age of LB (assessed by the Lefabvrais French reading test) was more than two years behind expectations whereas that of her sister was above average. Further, in contrast to her sister and healthy control subjects, LB exhibited specific deficits in elaborate metaphonological awareness abilities (non-word repetition, rhyme production, phonemic segmentation and syllabic inversion). These could be linked to temporal lobe dysfunction, thus confirming the important role of the temporal lobes in reading acquisition.

Deep dyslexia in the two languages of an Arabic/French bilingual patient.

We present a single case study of an Arabic/French bilingual patient, ZT, who, at the age of 32, suffered a cerebral vascular accident that resulted in a massive infarct in the left peri-sylvian region. ZT's reading displays the characteristics of the deep dyslexia syndrome in both languages, that is, production of semantic, visual, and morphological errors, and concreteness effect in reading aloud and impossibility of reading nonwords. In the first part of this paper, using a three-route model of reading, we account for the patient's performance by positing functional lesions, which affect the non-lexical, the semantic lexical and the non-semantic lexical routes of reading. Phonological priming observed in a cross-language visual lexical decision task indicates that implicit assembled phonological recoding is possible. The above lesions and implicit nonword reading characterize the output form of deep dyslexia. However, error distribution reveals dissociations across languages (e.g. the semantic error rate is higher in French whereas translations are more frequent in the Arabic testing) that cannot be accounted for within a three-route model. In the second part, extensions to Plaut and Shallice's connectionist model (Cognitive Neuropsychology, 10 (5) (1993) 377) are proposed to account for the translinguistic errors observed. ZT's error distribution is compared to that obtained by Plaut and Shallice after lesions had been applied at different locations through the 40-60 network. The overall syndrome of deep dyslexia found in both languages is explained as resulting from lesions along the direct (O-->I) and output (S-->Ip, Ip-->P) pathways of reading. Lesions along the output pathway mostly affecting S-->Ip connections in French and Ip-->P connections in Arabic account for discrepancies in ZT's error pattern across tasks and languages. This case study demonstrates the superiority of a connectionist approach for predicting the error pattern in deep dyslexia.

Phonological awareness in French-speaking children at risk for reading disabilities.

We report the phonological awareness abilities of preliterate French-speaking children. The performance of a group of children identified At Risk (n = 26) for reading disabilities was compared to that of normally developing age-matched controls (n = 22) on a range of standardised and experimental tests. Results showed the At Risk children to have a selective impairment in expressive relative to receptive language, whereas Controls performed at equivalent levels on both measures. Although the children At Risk performed at a significantly lower level than Controls on all but one of the metaphonological tests, their pattern of performance was similar to that of Controls, suggesting a developmental delay. Interestingly, both groups showed a superiority of awareness for syllables over phonemes, reflecting the phonological structure of the French language.

Interaction between verbal and gestural language in progressive aphasia: a longitudinal case study.

The objective of this longitudinal study is to investigate the on-line interaction between praxis and linguistic abilities in a progressive aphasia case. During 3 years of evolution, procedural discourse of a progressive aphasic patient was videotaped five times, allowing us to analyze the progression of both language and gestural production as well as the interaction between these two. We anticipated that, in the absence of apraxia, the patient would compensate for her speech deficit by producing progressively more and more meaningful gestures. Our compensatory hypothesis was confirmed but the compensation was not as efficient as one would expect given the absence of apraxia. With the progression of the speech deficit, the patient could not replace some verbs by pantomimes that were otherwise accompanying her discourse in the preceding testing sessions. We suggest that such a compensatory ability may constitute one important characteristic of the progressive aphasia syndrome.

Laparoscopic investigation of the bovine ovary in the periovulatory phase of the cycle.

Laparoscopy, in combination with a rapid radioimmunoassay for plasma-LH determination, has been used to predict and observe ovulation in heifers. Experiments on three animals with typical progesterone levels, LH levels and apex formation are described. Ovulation was observed from 25 h to 29 h after the beginning of LH rise and from 17 h to 19 h after LH peak. The LH peak lasted for 9 h to 11 h. Cow ovulation was observed and photographed. The preovulatory follicle, apex formation, ovulation and freshly ruptured follicles are illustrated. The results presented here demonstrate that laparoscopy could offer valuable diagnostic assistance in clinical veterinary medicine.

[Ovulation prediction in cattle by rapid measurement of plasma LH and by laparoscopic observation]. / Prédiction de l'ovulation chez le bovin par dosage rapide de la LH plasmatique et observation de l'ovulation par laparoscopie.

The last hours of intrafollicular maturation are important to preserve the potential of oocytes for fertilization and development. To collect mature oocytes it is consequently essential to predict accurately the time of ovulation. Therefore we have modified a regular and specific plasma LH radioimmunoassay to a convenient assay providing reliable results within four to five hours. Using this technique we have been able to detect the LH peak with a delay small enough to predict the moment of ovulation; then we have been able to observe and photograph ovulation. The antigen-antibody reaction takes place during a two hour incubation at 37 degrees C. The immune complex is precipitated by addition of a rabbit anti-gamma-globulin and incubation at 22 degrees C for 30 minutes. The variation between fast and regular assays is lower than 15%. From a study of 25 cycles in 12 animals we suggest intervals of approximately 27 hours between the beginning of the LH peak and ovulation and of about 17 hours between the end of the peak and ovulation. Intervals between the beginning of heat and ovulation appear irregular and cannot be used with certainty as a reference point to predict ovulation. Five ovulations were observed closely and in the five cases, the formation of an apex was noted Our results clearly show that with the technique mentioned above we can predict rapidly and precisely bovine ovulation.

Prediction of bovine ovulation by a rapid radioimmunoassay for plasma LH.

A commonly used and specific plasma LH radioimmunoassay was modified to provide reliable results for cow LH concentrations in blood within 4-5 h. Blood samples were collected at 2- or 4-h intervals from at least 24 h before the expected oestrus until after its onset. Thereafter, samples were collected at intervals of 2 or 4 days until the next oestrus. For the assay, the antigen-antibody reaction took place during a 2-h incubation at 37 degrees C. The immune complex was precipitated by addition of rabbit anti-gamma-globulin and polyethylene glycol followed by an incubation at 22 degrees C for 30 min. The coefficient of variation between this assay and the standard assay was less than 15%. From a study of 25 cycles from 12 animals, we obtained intervals of congruent to 27.3 h between the beginning of the LH peak and ovulation and congruent to 17.5 h between the end of the peak and ovulation. This modified technique can be used to predict rapidly and precisely the time of ovulation in cattle.