ABSTRACT
The consequences for cognitive ability of neuronal migration disorders (NMDs) remain a relatively unexplored area of neuropsychological research. One possible reason for this is the strong a priori probability that considerable variations in cognitive competence can be expected in patients who are united by a diagnostic category but who may have markedly different neural lesion sites. In addition to wide variation in the location of brain lesions, considerable variation with respect to lesion size and number has also been acknowledged in individuals with NMDs. The impact of the characteristic lesions seen in NMDs is further complicated by the possibility that lesions may also be epileptogenic foci. Given this variability and complexity, dissociating and quantifying the contribution of epilepsy and brain lesions to cognitive dysfunction has remained a substantial challenge.
