About a year after Michael was diagnosed with the Chiari malformation, he underwent a three-and-a-half-hour procedure to remove a small piece of his skull and a piece of a vertebra to ease the pressure on his brain. At the same time, the surgeon repaired a portion of his dura, the outermost layer of the meninges. Dura should be tough, but the surgeon reported that Michael’s, for some reason, had the consistency of wet newspaper.
Even so, the surgery seemed to go well. Within 24 hours, though, Michael developed meningitis, a rare infection of the meninges. He recovered, but 10 weeks after the surgery, he began to have seizures. At first, they were sporadic, but within two years Michael was having a severe seizure every week. He would suddenly stop moving and then slowly begin to circle the room in a trancelike state. His lips would sometimes turn blue, signaling a lack of oxygen. Doctors suggested giving him Diastat (diazepam)—an anticonvulsant drug—if a seizure lasted more than five minutes. Even with the medication on hand, his mother sometimes panicked and called 911.
In June 2014, when Michael was 13 years old, he had his first convulsive seizure. His father was just drying him off after a shower when his 180-pound body went limp. His parents realized they could no longer keep him safe at home. That October, Michael moved into a residential facility in Media, Pennsylvania, a 10-minute drive from their house. Michael had his final seizure 18 months later.
When Michael died, Bolen’s Google search led her to Autism BrainNet, a network of brain banks set up in 2014 to preserve the brains of people with autism for research. (Autism BrainNet is funded by the Simons Foundation, Spectrum’s parent organization.) She called the network’s main number, and the organization worked with a local agency to collect Michael’s brain and ship it to Hof’s lab at Mount Sinai.
* * *
Brain banking is a finely tuned science, aimed at maximizing the research potential of each precious sample. Each brain is first dissected into its two halves, or hemispheres. One hemisphere is then cut into slabs about 1 centimeter thick; the slabs are quickly frozen in liquid nitrogen and stored in labeled bags. These can be kept in a deep freezer for years, if not decades.
The other hemisphere is typically submerged in a pungent formaldehyde bath that hardens the tissue and fixes each cell in place. Some brain banks keep this fixed hemisphere whole. Others cut it into slabs of tissue, also about a centimeter thick. They can store these slabs in tubs of formaldehyde in a walk-in refrigerator or embed them in paraffin wax and maintain them at room temperature. They can later shave the waxed blocks into delicate slices for inspection under a microscope as needed.
Imaging studies can provide clues to when and where brain development is altered in autism, but only postmortem tissue can reveal how development goes awry. “You have to be looking at the individual cells in those brain regions that appear to be developing differently,” says Cynthia Schumann, an associate professor of psychiatry and behavioral sciences at the University of California, Davis, MIND Institute.