Pathological laughter and behavioural change in childhood pontine glioma.

Children with pontine glioma usually present classically with ataxia, motor deficits and cranial nerve palsies. The pons has generally not been regarded as a structure that mediates complex affective behaviour. However, we report nine children who either at the time of presentation or progression demonstrated marked behavioural changes manifesting as either "pathological laughter" or separation anxiety in the form of school refusal. A mechanism of how pontine lesions can cause such complex affective and cognitive behaviour has been suggested to consist of the disruption of a network of cerebro-ponto-cerebellar pathways and the evidence for this mechanism is discussed.