Brainstem biopsy

Comments

Uncommon as crosses the pia superior and inferior to the tentorium and places vital vasculature and cranial nerves at risk

For lesions of the lower midbrain, pons, and rostral medulla projects through the ipsilateral middle cerebellar peduncle, pain associated with muscle dissection before making the twist drill hole in the skull. A more decisive contraindication to this approach is the risk for posterior fossa subdural hematomas caused by blind puncture of the cerebellar cortex

Midbrain, upper pons, and medulla. For lower pons or medulla biopsies, an ipsilateral transfrontal approach necessitates a trajectory traversing the lateral ventricle before entering the anterior thalamus, cerebral peduncle, and then the brainstem. Lateral midbrain, a trajectory lateral to the ventricle suffices.Approaching the pons and medulla with this method often requires entering the frontal horn of the lateral ventricle, which violates two ependymal surfaces and places the patient at risk for intraventricular hemorrhage. Second, ventriculostomy may lead to intraoperative loss of cerebrospinal fluid, which may contribute to postoperative headache and shifting of intracranial contents, thereby possibly altering the location of the target. Third, this route is limited to midline regions of the pons and midbrain by the tentorial incisura

Lesions below lower pons, and lateral pontine lesions. An intraparenchymal trajectory is projected to avoid the lateral ventricle, the tentorium, major vessels, and the cerebral aqueduct