Louise Gagnon

Questioning the Validity of the Semantic-Pragmatic Syndrome Diagnosis

The classification of developmental language disorders has recently witnessed the birth of a subsyndrome, semantic-pragmatic syndrome, used to describe the case of children with specific language and communication impairments. However, there are striking similar-ities between children with semantic-pragmatic syndrome and those with high-functioning autism on a communicative, behavioural and cognitive level. This article questions the validity of semantic-prag-matic syndrome as a diagnostic concept distinct from high-function-ding autism and, consequently, its use as a clinical entity.

CACNA1A haploinsufficiency causes cognitive impairment, autism and epileptic encephalopathy with mild cerebellar symptoms

CACNA1A loss-of-function mutations classically present as episodic ataxia type 2 (EA2), with brief episodes of ataxia and nystagmus, or with progressive spinocerebellar ataxia (SCA6). A minority of patients carrying CACNA1A mutations develops epilepsy. Non-motor symptoms associated with these mutations are often overlooked. In this study, we report 16 affected individuals from four unrelated families presenting with a spectrum of cognitive impairment including intellectual deficiency, executive dysfunction, ADHD and/or autism, as well as childhood-onset epileptic encephalopathy with refractory absence epilepsy, febrile seizures, downbeat nystagmus and episodic ataxia. Sequencing revealed one CACNA1A gene deletion, two deleterious CACNA1A point mutations including one known stop-gain and one new frameshift variant and a new splice-site variant. This report illustrates the phenotypic heterogeneity of CACNA1A loss-of-function mutations and stresses the cognitive and epileptic manifestations caused by the loss of CaV2.1 channels function, presumably affecting cerebellar, cortical and limbic networks.

Superior estimation abilities in two autistic spectrum children

Anecdotal reports of superior estimation abilities in autistic individuals (e.g., Sacks, 1985) have never been confirmed empirically. We present here case studies of 2 children with autistic spectrum diagnoses and report remarkable abilities in estimation for several quantifiable dimensions. K.T. and G.T. were tested at 9 years of age for estimation of rank, numerosity, time, weight, length, surface, distance, and precise enumeration for small numbers. Their performances were compared to those of 6 age- and IQ- matched comparison children. K.T. demonstrated a superior level of performance in estimating rank (e.g., which set has larger numerosity?) but his performance in other tasks was average. G.T. displayed outstanding performance in estimating numerosity, time, weight, surface, length, and distance, with average performance in other tasks. These results show that certain autistic spectrum individuals may develop superior and highly specialized abilities in estimation. We discuss these findings in relation to the role of “veridical mapping” in the development of special ability (Mottron, Dawson, & Soulières, 2009; Mottron, Dawson, Soulieres, Hubert, & Burack, 2006a). Veridical mapping is the detection of isomorphism within a code, between two codes, or between one code and isomorphic elements of the world. Within this framework, it is proposed that estimation abilities, like absolute pitch, rely on the ability to map a verbal code with a specific magnitude of a psychophysical dimension.

Neuropsychological functioning in children with temporal lobe epilepsy and hippocampal atrophy without mesial temporal sclerosis: A distinct clinical entity?

Unilateral hippocampal atrophy (HA) is considered as a precursor of mesial temporal sclerosis (MTS) in some patients with temporal lobe epilepsy. However, in other cases, it has been suggested that HA without MTS may constitute a distinct epileptic entity. Hippocampal atrophy without MTS was defined as HA without T2-weighted hyperintensity, loss of internal architecture, or associated lesion seen on the MRI data. To date, no study has focused on the cognitive pattern of children with epilepsy with HA without MTS. The objectives of the present study were to characterize the cognitive profile of these children and to investigate the presence (or the absence) of material-specific memory deficits in these young patients, as found in patients with MTS. Toward this end, 16 young patients with epilepsy with either left or right HA without MTS completed a set of neuropsychological tests, assessing overall intelligence, verbal memory and nonverbal memory, and some aspects of attention and executive functions. Results showed normal intellectual functioning without specific memory deficits in these patients. Furthermore, comparison between patients with left HA and patients with right HA failed to reveal a material-specific lateralized memory pattern. Instead, attention and executive functions were found to be impaired in most patients. These results suggest that HA may constitute a distinct epileptic entity, and this information may help health-care providers initiate appropriate and timely interventions.