" Yes, they can occur at any age. We have some of the autoimmune causes in six-month-old babies and yet, we have autoimmune causes in people who are 90 years old. For CJD, the youngest sporadic patient I’m aware of is 12 years old, the oldest is 96. But the peak age is in the early 60s. That’s the most common age for CJD and probably for most rapidly progressive dementias. But I have patients in their 20s, 30s. When they’re that young, often it’s a genetic disorder, an inborn error of metabolism. They can be a little harder to diagnose. Sometimes we have to do more complicated, urine, blood, spinal fluid analyses to detect inborn errors of metabolism. "