Cerebellar Mutism Syndrome in Children and Adults

Cerebellar mutism can be considered the hallmark feature of the cerebellar mutism syndrome (CMS), previously also frequently termed the posterior fossa syndrome (PFS). The syndrome consists of specific linguistic, cognitive, behavioral, and affective symptoms following acute posterior fossa damage in children and adults. Although the symptoms have been exceptionally associated with non-tumoral etiologies, CMS usually develops after a brief period of relatively normal functioning in the immediate postoperative phase following posterior fossa tumor surgery. The incidence of CMS in the pediatric population is estimated to range between 7% and 50%. Although similar symptoms have been occasionally reported in adults, CMS is typically viewed as a clinical condition affecting children. An international consensus as to the definition of CMS was recently reached. However, this accepted definition specifically addresses the pediatric variant of the syndrome associated with posterior fossa surgery (postoperative pediatric CMS, POPCMS). In this chapter, the more general term CMS (instead of POPCMS) will be used to denote similar symptoms also occurring in adults, and with non-tumoral etiologies. Although the semiology of CMS has extensively been described, the underlying pathophysiological mechanisms still remain largely unclear. This chapter presents a brief overview of the intriguing semiological combination of transient cerebellar mutism and cognitive, behavioral, and affective alterations following acute posterior fossa lesions. Furthermore, the most important pathophysiological hypotheses and the proposed therapeutic interventions will be briefly discussed.