[Scribble]

Here I am again, really eager to find the answer. This may be interesting, actually:

Spoiler:

Read this:


Brain injury can occur in many ways. Traumatic brain injuries typically result from accidents in which the head strikes an object. This is the most common type of traumatic brain injury. However, other brain injuries, such as those caused by insufficient oxygen, poisoning, or infection, can cause similar deficits.

Mild Traumatic Brain Injury (MTBI) is characterized by one or more of the following symptoms: a brief loss of consciousness, loss of memory immediately before or after the injury, any alteration in mental state at the time of the accident, or focal neurological deficits. In many MTBI cases, the person seems fine on the surface, yet continues to endure chronic functional problems. Some people suffer long-term effects of MTBI, known as postconcussion syndrome (PCS). Persons suffering from PCS can experience significant changes in cognition and personality.
[/B]

Now, in the beginning of episode 2, Kei reads the newspaper article and is shocked. Then Rena appears with her machete, which scares the life out of Kei, who falls onto the wreckage....probably bumping his head in the process. This is perhaps the first step in making Kei go insane? Maybe the image of the knife and scary Rena is printed on his brain, and he associates it with the murder in the newspaper, the first step towards his downfall? I can't really explain it that well, but you get the jist.

As for the syringe, I don't think it exists.