(akinetic mutism)

Prevalence: occurs, according to the series, in 8 to 24 % of the patients operated for a tumor in the posterior cranial fossa. It is by definition the delayed appearance (within 48 hours but up to 8 days after surgery) in children of mutism (or a reduction of speech) associated with emotional lability after an intervention at the level of the cerebellum or the 4th ventricle. Frequently associated are: hypotonia, oropharyngeal dysfunction (dysphagia), motor cerebellar signs, and signs of dysfunction of the brainstem (involvement of the cranial nerves, pyramidal signs). This is a transient disease but the recovery is slow and often incomplete.

Risk factors: a tumor of the medulloblastoma type especially if it is located at the level of the vermis cerebelli or the median line, involvement of the brain stem, preoperative disorders of speech, radical resection, young age, incision of the vermis.

It seems to be a consequence of dysfunction of the dentothalamocortical track that plays an important role in the coordination of the functioning of the cerebellum and the cerebral cortex: this is an example of diaschisis, i.e. the complex interplay between focal lesions, a dynamic network and functional changes in remote areas. It is likely that post-operative edema and vasospasms have a central role in the process.

Anesthetic implications: 

keep this diagnosis in mind when faced with neurological problems appearing after a surgery of the posterior cranial fossa.

References : 

-         Chao JY, Liu C, Shetty N, Shah U.
Postoperative pediatric cerebellar mutism after posterior fossa surgery : a case report.
A&A Case Reports 2017; 8 : 213-5

Updated: April 2017