Of a series of 15 children operated for cerebellar tumor at University Hospital Rotterdam-Dijkzigt, The Netherlands, 5 developed “cerebellar mutism” and subsequent dysarthria after surgery, and 2 had mild speech problems. Of 8 without speech problems, 7 had astrocytomas, with involvement of a cerebellar hemisphere. Of the 5 with mutism, 4 had medulloblastomas, and all had tumors that lined the fourth ventricle. Mutism was delayed for 1 to 2 days after surgery. Alternating movements of the tongue were impaired but no paresis of bulbar muscles was evident in mute patients. The duration of mutism varied from 3 to 8 weeks. Speech was regained suddenly and unexpectedly, and the severe dysarthria that followed lasted for 1 to 5 weeks. Recovery was associated with normalization of tongue movements. Factors predictive of mutism were 1) tumor filling and adherence to the floor of the fourth ventricle; 2) shunting for hydrocephalus prior to surgery; and 3) postsurgical edema of the pontine tegmentum. 
COMMENT. The authors cite 36 cases of cerebellar mutism from the literature. An additional 2 cases are reported in Progress in Pediatric Neurology Vol. II, Chicago, PNB Publishers, 1994, pp219-220. The complication was correlated with the amount of the posterior vermis resected. One tumor was a medulloblastoma and the other an astrocytoma. Speech was regained after 2 months.
A case of mutism followed by dysarthria and agrammatic speech is reported in an adult after a right cerebellar infarction.