PROCEDURES FOR BRAIN AUTOPSY IN PRION DISEASES
- The autopsy should be performed as soon as possible after death. However, the tissue can be examined successfully up to 48-72 hours post-mortem, especially if the body is refrigerated.
- The brain, the hemispheric dura and the pituitary gland should be split in half sagitally.
- The left cerebral hemisphere with the left dura and the left pituitary gland, left cerebellar hemisphere, left half of the vermis, and half of the brain stem should be fixed in formalin.
- The right cerebral hemisphere should be sliced coronally in ~1.5 cm (~1 inch) slices.
- The right cerebellum and brain stem should be sliced horizontally in slices of ~1.0 cm (3/4 inch).
- The right half of the dura and the right half of the pituitary gland should be frozen uncut.
- Each coronal section should be immediately heat-sealed in a heavy-duty plastic bag. The outside of the bag is assumed to be contaminated with prions and other pathogens. With fresh gloves or with the help of an assistant wearing uncontaminated gloves, place the bag containing the specimen into another plastic bag, which has an uncontaminated outer surface.
- The brain slices should be frozen in a -80°C freezer (or, lacking that, in a -20°C freezer). It is important that the slices be frozen individually (not piled up) inside plastic bags (to avoid drying) while lying flat on a tray. However, they can then be put together in a plastic bag after they are frozen. Alternatively, the right half of the brain can remain uncut surrounded by dry ice. If you wrap slices to be frozen, please use plastic or aluminum foil, not paper towels.
- Cutting and sampling of fixed brains should be performed using BSL-2/BSL-3 precautions as described above until the brain samples are treated with formic acid for 1 hour. If paraffin sections are submitted, please cut 1 section 5 micron thick (for H.E.) and 3 sections 8 micron thick (for PrP immunohistochemistry).
If the above procedure for freezing half of the brain cannot be followed, at the very minimum, a coronal section of the cerebral hemisphere containing the thalamus (i.e., a slice containing the mammillary bodies) and 1-5 gram samples of brain tissue from the frontal and occipital lobes, the cerebellum, and the brain stem must be obtained and frozen while the remaining brain is fixed as above.
IMPORTANT NOTICE: The NPDPSC requires that a Testing and Reporting form be signed before the prion protein gene sequencing results can be reported. Please submit a Testing and Reporting form with blood, frozen brain biopsy tissue, or frozen brain autopsy tissue.
In order to provide effective surveillance for CJD and other prion diseases, we strongly recommend that an effort be made to have an autopsy performed in all suspected cases of prion disease. We are available to coordinate autopsies, and all of our services are provided free of charge. Please contact one of our Autopsy Coordinators at 216-368-0587 for more information.