Complex sentence: The helmet saves Kramer from an attack by "Crazy" Joe Davola, but leaves him suffering of unilateral neglect (forgets to dress half of his body properly, forgets to shave half his face, etc).
Split into simpler sentences: The helmet saves Kramer from an attack by "Crazy" Joe Davola. This attack leaves him suffering of unilateral neglect (forgets to dress half of his body properly, forgets to shave half his face, etc).