====== Occipital Lobe Retraction ======

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[[Occipital lobe]] [[retraction]] refers to the surgical [[maneuver]] of gently displacing or pulling back the occipital lobe to access deep [[midline]] structures.

===== Indications =====
It is commonly used in:
  * Pineal region tumors (e.g., pineocytomas, meningiomas, germinomas)
  * Collicular plate cavernomas
  * Posterior tentorial lesions
  * Vascular pathologies (e.g., Galenic system aneurysms)

Approaches where occipital lobe retraction is typically employed:
  * Infratentorial supracerebellar approach
  * Occipital transtentorial approach

===== Risks =====
Because the occipital lobe contains the primary visual cortex (Brodmann area 17), retraction carries significant risks:
  * Transient or permanent cortical blindness
  * Homonymous hemianopia
  * Visual field deficits
  * Posterior cerebral artery (PCA) infarction (due to vascular compromise)

> ''Case example (BMJ Case Rep, 2025): A woman developed complete cortical blindness after occipital lobe retraction during pineal meningioma resection. Vision recovered over several days.''

===== Technical Recommendations =====
To minimize risks:
  * Prefer gravity-assisted retraction (head positioning)
  * Minimize fixed retraction pressure and duration
  * Perform CSF drainage (lumbar or cisternal) to relax the brain
  * Maintain optimal perfusion pressure and avoid hypotension or hypoxia

===== Case reports =====

In a **Single-[[patient]] [[case report]]** detailing [[transient cortical blindness]] following [[pineal region meningioma surgery]]
**Yip et al.**
from the University of [[Edinburgh]] and NHS Lothian, Edinburgh, UK.
published in *BMJ Case Reports*, **June 27, 2025**; Volume 18(6):e264865.
to highlight the occurrence of **transient cortical blindness** following [[occipital lobe retraction]] during a pineal meningioma resection and raise awareness about anatomical risk factors.

===== Key Clinical Course =====
- Middle-aged woman with pineal meningioma causing triventriculomegaly.  
- Underwent ETV followed by tumor resection via **parieto-occipital interhemispheric approach**.  
- Post-op: **complete cortical blindness**, no MRI evidence of ischemia.  
- Gradual visual recovery: partial by 3 weeks, full by 8 months.  
- Implicated cause: **bilateral occipital retraction injury** despite uneventful surgery
((Yip NZW, Barbour-Hastie C, Barron P, McKee JB, Kaliaperumal C. Transient cortical blindness following occipital lobe retraction in a pineal region meningioma resection. BMJ Case Rep. 2025 Jun 27;18(6):e264865. doi: 10.1136/bcr-2025-264865. PMID: 40579192.)).

===== Critical Review =====
- **Strengths**:  
  - Describes a rare but important surgical complication, especially relevant in posterior fossa and pineal surgery.  
  - Clear clinical timeline with good recovery documentation.  
  - Highlights subtleties of non-ischemic cortical dysfunction and relevance of fMRI in post-op assessment.

- **Limitations**:  
  - Lack of **functional imaging** (e.g., fMRI, perfusion studies) to correlate with presumed retraction injury.  
  - No intraoperative monitoring data (e.g., visual evoked potentials) or detail on retraction technique.  
  - Tentorial angle mention is appropriate, but no imaging shown to support that anatomical claim.  
  - Single case, hence anecdotal and non-generalizable.

===== Final Verdict =====
- **Score**: 4.5/10 — educationally useful for neurosurgical awareness but limited by lack of objective neurophysiologic or imaging data.

===== Takeaway for Neurosurgeons =====
[[Occipital lobe retraction]]—even absent radiographic ischemia—can cause **reversible cortical blindness**, particularly in posterior approaches. Gentle retraction and patient selection (tentorial angle, age) may reduce risk.

===== Bottom Line =====
Transient cortical blindness may follow [[occipital lobe]] manipulation without infarction; full recovery is possible but underscores need for cautious occipital retraction during pineal region surgeries.

===== Citation =====
Transient cortical blindness following occipital lobe retraction in a pineal region meningioma resection.  
Yip NZW, et al. *BMJ Case Rep.* 2025;18(6):e264865. doi:10.1136/bcr-2025-264865.  
Corresponding author: Catriona Barbour-Hastie, catriona.barbour-hastie@nhs.scot