This may be a weird question to you, but...how's your weather? Is it hot and sticky, or raining (or trying to)? I think there's always a reason for any behavior, even if it's not evident on tests. If you have hot and humid weather, or you're getting ready to, he may be in pain from it. This is not a joke! Many of us experience severe changes in CSF pressure that result in pain, and they aren't necessarily obvious on test results. He may also be having some type of mild seizure. For 25 years, I had these annoying things several times a year for several days that went unIDed until I realized they were auras to bigger szs and they were then properly dx'ed as simple partial szs. They generally coincide with radical changes in the weather, such as season change and other things, such as hormonal irregularities or sleep disturbances.

Also, you say he's behaving this way for "no reason," but keep in mind that CT won't necessarily tell you everything you need to know. MRI is always better, and it can even take pressure monitoring to get to the bottom of what's going on. CSF pressure changes all the time, according to things like weather, body position, or illness (even minor ones, like colds or allergies). If he's super-sensitive to pressure changes, it would explain his behavior. This does not necessarily mean something is wrong with the shunt. Depending on the degree or impact of the hydro before treatment and the effectiveness of shunting, among other things still being IDed, pressure sensitivity can feel like shunt failure to some in certain situations. I will never drive (or even be a passenger) through a mountain range again, which is sad, because I used to attend college in the valley in the middle of the Blue Ridge. Last time I went anywhere near it, I was sure my shunt was failing. I was utterly miserable!

Just some things to consider...

LIZARD