gms | German Medical Science

Objective: Transient cerebellar mutism is a dramatic behavioural alteration in children operated for a posterior fossa tumour occuring several hours or days after surgery. Several predictive factors have been discussed.

Methods: Twenty-five boys and 22 girls (mean age: 6.8 years, range: 12 months to 16 years) had in total 55 surgical interventions (47 primary and 8 recurrent tumours) for a cerebellar astrocytoma (n=39) or ependymoma (n=8). 43 children were retrospectively and 4 prospectively evaluated. The occurrence of cerebellar mutism was correlated with several clinical factors such as age, sex, tumour location, size, and histology, first or repeat surgery, surgical approach, extent of resection, presence of hydrocephalus as well as preoperative symptoms.

Results: The incidence of cerebellar mutism 1 to 3 days after surgery was 30.9%. There was no significant influence on the occurrence of cerebellar mutism by age, sex, tumour location (vermal versus hemispheric), recurrent tumour, size of the tumour, hydrocephalus or preoperative symptoms. In contrast, predictors were the kind of surgical approach (81.3% incidence of mutism after incision of cerebellar vermis versus 16% without, P=0.0004), the extent of resection (63.6% incidence of mutism after subtotal versus 32.3% after gross total resection, P=0.048), and to a certain extent the histology (34% incidence in astrocytomas versus 18% in ependymomas).

Conclusions: It has been reported that splitting of the cerebellar vermis is frequently followed by postoperative mutism. This is the first report showing that the extent of surgical resection and also tumour histology are predictive factors for the occurrence of cerebellar mutism.