Age and Etiology as Predictors of Language Outcome following Hemispherectomy

Abstract

We report on the effects of etiology and age on the linguistic outcomes in a large pediatric hemispherectomy population. Four populations were considered separately: cortical dysplasia (multilobar involvement), Rasmussen’s encephalitis, infarction as a primary etiology and, fourth, children who failed to develop language, regardless of etiology. We argue against the ‘the-earlier-the-better’ hypothesis and propose our own hypothesis that weds maturational factors to etiological factors to predict language outcomes following pervasive brain insult. The implications of our ‘critical impact point’ hypothesis are discussed.

Improvement of language development after successful hemispherotomy

“…We found a significant increase in LQ in patients with shorter duration of epilepsy (p = 0.004). Other reports have previously found that a shorter period of overt seizures might be positive for better general developmental progress [2,12,24,27], which also holds true for language abilities [8,9,16]. Additionally, our results corroborate the finding that children who were off medication after surgery showed significantly better language outcomes (p = 0.003).…”

“…However, most reports published so far on language outcomes following hemispheric surgery have concentrated on anatomic hemispherectomy [8][9][10]21,22,31,35]. These studies concluded that seizure freedom [8][9][10]16] may be a favourable predictor whereas developmental pathologies may be linked with unfavourable language outcomes. The effects of functional hemispherotomy on development have been less extensively studied and the results are inconsistent [1,24,26,27].…”

Spoken Language Outcomes after Hemispherectomy: Factoring in Etiology

“…In what we had termed the ''Critical Impact Point'' hypothesis, we proposed that the point in both neurological and functional maturation at which the insult is suffered will determine the subsequent outcome (Curtiss & de Bode, 1999). Our current results refine this hypothesis in that we have found that the variable of etiology, itself, turns out to be the umbrella construct for age, extent, and the mechanism of injury.…”

GCS: A grammatical coding system for natural language data

“…Thus, although both formal test performance and language samples were used to evaluate language performance, it was for the analysis of the spontaneous speech samples that GCS was developed. Aspects of this research may be reviewed in Caplan, Curtiss, Chugani, and Vinters (1996), Curtiss and de Bode (1998, 1999a, 1999b, 2003, Curtiss, de Bode, and Mathern (2001), Curtiss and Schaeffer (1997a, 1997b), de Bode (1998), and de Bode and Curtiss (1999.…”