Brain damage and quiet weapons

I was thinking today about the appropriate level of brain damage is necessary to dispatch with a zombie. A significant trauma is enough to take them out, but what defines significant?

Since a gunshot is probably the simpliest, most effective way of braining a zombie. We should examine what causes this significant level of damage. As we all know from countless police dramas, Mythbusters, and other crime scene investigation type shows, the real damage caused by a bullet, is not the impact it makes, but rather less graceful exit.

However, guns are not always the most appropriate way of taking out a zombie. Unless you have a silencer (which through extended use loses its silencing capabilities), gunshots are inevitably loud and attention drawing. Quieter alternatives are occasionally needed.

Max Brooks discusses quiet ranged weapons more in-depth on pages 38-41 of The Zombie Survival Guide, so I will just highlight some of his points,
The crossbow, and moreso, the handbow, are probably the best bet for a generally unskilled individual. They are easier to aim, and the ammo is relatively small. Brooks is rather quick to discount the compound bow because of the amount of skill necessary to use it. Since I grew up in deer-hunting country and have met quite a few bow hunters with lethal accuracy, I do feel that the select group of individuals who can handle the compound bow is a larger group than Brooks predicts. It should be noted that the time to reload means that you need to be effective in the first shot.
But do handbows and compound bows have the stopping power? Though they do not effect the larger area of damage produced by the exit wound of a gunshot, and accurately placed arrow seems to be just as lethal. Moreover arrows are reusable (for the eco-friendly zombie hunter who prefers not to litter), but this does necessitate retrieving them.

Brooks dislikes ninja-type weapons such as shuriken (throwing stars) and kunai knives (throwing knives) for the amount of skill necessary to operate them. Again, I would be interested in trying them before dismissing them so quickly. Though I do agree that they probably cannot deliver a lethal bow in the hands of an amateur, they may be able to serve a slowing function. Still there are many more drawbacks. Much like the katana, actual weapon-grade ninja weapons are difficult to find. Since much of the shuriken and kunai knives effectiveness depends on their sharpness and durability, only found in professional (non-showy weapons).
Penetration is another question here. Bullets and arrows have good penetration because much of the driving force is mostly dependent on the weapon, not quite as much on the user. However, shuriken and kunai are dependent on the user directly delivering the weapon. The amount of force generated is directly related to the talent, and strength of the user.

This brings us back to the original question about what defines significant damage. If one were to throw a shuriken and lodge it in the skull, but not penetrate the skull, would that be enough to kill a zombie? Or would it only destroy the function that part of the brain enables?

This definitely necessitates further research into both lethal brain damage, and alternative long-range weapons. With that in mind, I’m popping in Resident Evil and going to sleep.