Cerebellar Mutism Syndrome (CMS)
Cranial Nerve Deficits
CNs VI–XII are especially at risk depending on tumor location.
May result in dysphagia, dysphonia, facial palsy, diplopia, or tongue weakness.
Ataxia
Due to direct damage or edema in the cerebellar hemispheres or vermis.
Hemiparesis or Quadriparesis
If the brainstem is involved or manipulated, especially the corticospinal tracts.
Hydrocephalus
Obstructive, either pre-existing or iatrogenic due to postoperative swelling or bleeding.
May require external ventricular drain (EVD) or ventriculoperitoneal (VP) shunt.
🧠 Vascular Complications Hemorrhage
Intraoperative or postoperative, possibly leading to mass effect or acute hydrocephalus.
Stroke
Ischemic damage due to manipulation or vasospasm of perforating arteries supplying brainstem/cerebellum.
🌡️ CSF-Related Complications CSF Leak
Due to violation of dura or poor closure; increases risk of meningitis.
Pseudomeningocele
Fluid collection under the skin at the surgical site.
Infection
Meningitis or abscess, especially if CSF leak is present.
🏥 Systemic Complications Respiratory Compromise
Especially in brainstem or lower cranial nerve involvement.
May require prolonged intubation or tracheostomy.
Dysphagia & Aspiration
Due to cranial nerve IX and X involvement; can lead to pneumonia.
🟡 Delayed or Chronic Issues Persistent Ataxia or Balance Problems
Neurocognitive Dysfunction
Especially in children; includes attention deficits, learning problems.
Hormonal Dysfunction
If surgery affects the hypothalamic-pituitary axis (less common in posterior fossa unless tumor extends rostrally).
Psychiatric Issues
Depression, emotional lability, or behavioral changes.