Mutism after surgery in the posterior fossa

A hitherto unsolved postoperative phenomenon after surgical removal of midline tumors of the cerebellum in children is the so-called "cerebellar mutism" or "posterior fossa syndrome". Although the symptoms are usually temporary, the children often suffer from social and cognitive deficits in later life and the associated restrictions in quality of life. It is possible that injuries to midline structures, which can occur during neurosurgical procedures to remove such tumors, are involved. Which brain structures play a decisive role in this is not yet fully understood.

In experimental work, we have already shown that in adolescent rats, bilateral lesions of the fastigial nucleus, a very small brain region in the midline area of the cerebellum, lead to reduced social interaction and motor coordination during further development. In adulthood, additional cognitive deficits occur, the pattern of which shows parallels to the cognitive-affective cerebellar syndrome in humans. Electrophysiological measurements during various behavioral tasks show altered neuronal activity in frontal cortex areas. These findings suggest a modulatory function of the fastigial nucleus for higher cognitive processes.