Is hemiplegia due to a porencyphic cyst a type of birth defect?

Cyst is the defect. The porencephalic cyst by itself is considered a birth defect. The neurological consequence of the cyst, the hemiplegia is more a side effect than a birth defect. This is similar to the lower limb paralysis that would be expected with an open spine defect -spina bifida. In both cases, function of normal nerves is distorted or lost due to the defect.