Lecture on Skull Landmarks and Frontal Lobe Surgery

Skull Landmarks

Glabella: Reference point for measurement.
Coronal Suture:
- Located 0.13 cm behind the glabella.
- Opening made 6 cm above zygoma along the coronal suture.
- Coronal suture on the inside of the skull should be noted.
Sphenoidal Ridge: Critical to avoid penetrating behind this ridge to prevent artery laceration.

Sylvian and Rolandic Fissures: Bound the frontal lobe.
Corpus Callosum:
- Genu located on the mesial hemisphere.
- Association pathways are crucial.
Fascicular Singuli & Internal Capsule:
- Singuli skirts corpus callosum into temporal lobe.
- Internal capsule's anterior limb is important.
Caudate Nucleus & Thalamus:
- Lobotomy incision is anterior to caudate nucleus.
- Thalamus radiates into temporal, occipital, and frontal lobes.

Patient Preparation:
- Head shaved to the vertex.
- Markings:
  - 3 cm behind the lateral orbit rim.
  - 6 cm above the zygoma.
  - 13 cm from glabella in midline.
- Line drawn over vertex along coronal suture.
Surgical Steps:
- Local anesthesia possible if patient is cooperative.
- Incision exposes coronal suture; periosteum scraped.
- Bore hole in coronal suture, enlarged by rongeur for knife access.
- Dura opened, cortex punctured in avascular area.
Leucotome Insertion:
- Guided by neurologist to maintain coronal suture plane.
- First incision penetrates from one skull opening to the other.
- Locate faults in midline; avoid anterior cerebral artery.
- Avoid anterior perforated space.
- Upper quadrant cut in coronal suture plane.
Incision Irrigation and Management:
- Irrigated with saline to control hemorrhage.
- Radial stab incisions made to prevent bleeding and sever frontal lobe fibers.
- Disorientation possible during fiber severance.
Completion and Verification:
- Procedure repeated on opposite side.
- Iodized oil injection for x-ray location verification.
- Important for ensuring proper incision placement.