Localization of focal cortical lesions influences age of onset of infantile spasms.

PURPOSE: To determine whether the localization of focal cerebral lesions affects age of onset of infantile spasms (IS).

METHODS

We reviewed 216 cases of IS and identified patients with focal cerebral lesions confined to frontal, centrotemporoparietal, or occipital regions. The age of onset of spasms in each of the three groups was analyzed.

RESULTS

Ninety-three patients were found to have focal cerebral lesions confined to one of the three regions previously described. The mean age of onset of IS was 3.36 +/- 1.71 months in patients with occipital lesions, 6.26 +/- 2.68 months in centrotemporoparietal lesions, and 9.83 +/- 2.56 in frontal lesions.

CONCLUSIONS

Occipital lesions are found to be associated with earliest onset of spasms, whereas frontal lesions are rare and associated with latest spasms onset. The age distribution pattern of spasms onset according to localization of cortical lesion is in close correlation with that of normal sequence of brain maturation. This supports the hypothesis that cerebral lesions located in critical areas of brain maturation have a role in the genesis of infantile spasms.