- Separate the hair and incise the scalp across the vertex from one mastoid process just behind the ear to another.
- Reflect the scalp forwards and backwards past the hairline. Note injury to skull or deeper tissues of scalp.
- Cut temporalis and masseter muscles on either side.
- Cut the calvarium with the saw in a slightly "V" shaped fashion. Remove the skull cap by inserting and twisting chisel at the sawline.
- Examine meninges and note extradural or subdural hemorrhage if any.
B. Removing the Brain:
- Open superior longitudinal sinus. Examine for antemortem thrombus.
- Cut dura along the sawline of skull and reflect towards the midline. Inspect the surface of brain.
- Retract the frontal poles and cut anterior attachments of falx cerebri (i.e cribiform plate).
- Elevate olfactory bulbs by inserting fingers between the frontal lobes and skull and drawing them backwards, retract the brain and cut: optic nerves, carotid arteries and other nerves.
- Retract brain medially and cut tentorial attachments along the petrous ridges.
- Retract brain posteriorly and cut remaining cranial nerves as close to bone as possible, vertebral arteries and spinal cord as distally as possible within the spinal canal.
- Retract cerebellum and brainstem. Support brain and cut remaining dural attachment with scissors. Remove the brain from the cranial vault.
C. Dissecting the brain:
- Brain can be fixed in 10% formalin to dissect later or it can be dissected at the moment.
- Remove brainstem and cerebellum by thin knife section across the the cerebral peduncle in a planes perpendicular to the brainstem and aqueduct.
- Perform serial cross-section of the brainstem along the same plane and inspect for substantia nigra in medulla.
- Cerebellum may be sectioned in a plane parallel to the long axis of brainstem. Observe the vermis and dentate nucleus.
- Carefully inspect for surface vessels, cranial nerves, midline structures i.e. cingulate gyri, unci, mammilary body, pineal recess and the remaining part of brainstem.
- Use serial coronal section at about 1 cm interval for the dissection of cerebral hemispheres. Examine the corpus callosum, thalamus, internal capsule and basal nuclei.
Postmortem brain dissection (Autopsy)