Posterior fossa syndrome following brain tumour resection: review of pathophysiology and a new hypothesis on its pathogenesis.
BACKGROUND
Posterior fossa syndrome (PFS), also known as cerebellar mutism syndrome (CMS), is a severe complication affecting children following surgery for posterior fossa brain tumours. Its incidence varies between 8 and 31 %, and its exact pathogenesis remains unclear. In this article, we aim to review the existing theories on its pathogenesis and propose a new hypothesis.


CONCLUSIONS
There is varying level of evidence on existing theories on the pathogenesis of PFS following surgery. These include cerebellar perfusion deficits due to vasospasm, oedema or axonal injury due to direct surgical injury and neuronal dysfunction. There is emerging evidence that interruption of the dentato-thalamo-cortical (DTC) pathway is responsible for PFS. Based on our experience with intraoperative MRI, radiological and pathological evidence on heat-related brain injury, we propose a new hypothesis implicating thermal injury resulting from the use of the Cavitron Ultrasonic Aspirator (CUSA) as an important mechanism in the pathogenesis of PFS.


CONCLUSIONS
The pathogenesis of PFS is likely to be multifactorial with direct injury from surgery being a major factor. We believe that thermal injury in addition to mechanical injury to the proximal segment of the DTC plays an important role in the pathogenesis of PFS and should be considered in future research related to the aetiology, prevention and management of PFS.
Department of Radiology, Alder Hey Children's NHS Foundation Trust, Eaton Road, Liverpool, L12 2AP, UK. shivaram.avula@alderhey.nhs.uk.
Shivaram
http://orcid.org/0000-0003-1742-7206
S
Avula
Department of Neurosurgery, Alder Hey Children's NHS Foundation Trust, Liverpool, UK.
Conor
C
Mallucci
Department of Neurology, Alder Hey Children's NHS Foundation Trust, Liverpool, UK.
Ram
R
Kumar
Department of Oncology, Alder Hey Children's NHS Foundation Trust, Liverpool, UK.
Barry
B
Pizer
D001932:Brain Neoplasms / Q000601:surgery; D002526:Cerebellar Diseases / Q000209:etiology*; D003388:Cranial Fossa, Posterior / Q000473:pathology*; D006801:Humans; D015192:Infratentorial Neoplasms / Q000209:etiology / Q000601:surgery; D009155:Mutism / Q000209:etiology*; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011183:Postoperative Complications / Q000209:etiology*
CUSA; Cerebellar mutism syndrome; Hypothesis; Pathophysiology; Posterior fossa syndrome; Review