Postoperative speech impairment (POSI) is the major component of a severe neurological complication of tumour surgery in the posterior fossa in children known as the cerebellar mutism syndrome.
In a prospective multicentre study, we included 500 children undergoing surgery of a brain tumour in the posterior fossa and followed them over time to detect clinical risk factors for the development of POSI and the subsequent improvement of speech.
POSI occurred in 30% of our patients. Half of the speech impaired patients regained the ability to speak within 16 days of surgery; however, several patients remained mute for more than 40 days.
We found that neither transvermian surgical approach, as compared with telovelar approach, nor left-handedness, as compared with right handedness, were associated with a higher risk of POSI. Yet we confirmed that younger children with high-grade tumours located in the midline were at the highest risk. Interestingly, we were the first to report a lower risk of POSI in secondary compared with primary tumour surgery.
These findings most importantly clarify that the decision of type of surgical approach for brain tumour surgery in the posterior fossa in children should not depend on an anticipated risk of POSI.