The spectrum of neurobehavioural deficits in the Posterior Fossa Syndrome in children after cerebellar tumour surgery
Introduction: The Posterior Fossa Syndrome (PFS) may occur in children after resection of cerebellar tumours. The most common feature is mutism, but also oropharyngeal dyspraxia, emotional lability and neuropsychiatric symptoms occur. We analysed the spectrum of behavioural abnormalities, speech and language characteristics during PFS. Methods: In order to identify PFS, all children with a cerebellar tumour admitted to our centre in the study period were prospectively assessed before and after tumour surgery. In the case of PFS, children were systematically followed by means of a standard protocol that included a daily neurological examination and assessment of speech behaviour. Speech was recorded on videotape before and immediately after surgery, and in cases of PFS at as short possible intervals for 4 weeks and subsequently every second week until the recurrence of speech and normalisation of behaviour. Data regarding clinical and behavioural features, duration of symptoms and mode of recovery were collected. Pre- and postoperative MRI data were studied. In 13 children with and two children without PFS a99mTc-hexamethylpropyleneamine oxime-Single Photon Emission Tomography (SPECT) scan could be performed. Results: PFS occurred in 41 of 148 children. During recovery all children were dysarthric, but only in a few speech features specific for cerebellar dysarthria occurred. A significant correlation was found between duration of mutism and severity of neurological symptoms. Significant correlations were also found between duration of mutism and abnormalities on SPECT scans of the left temporal lobe, the left and right basal nuclei, and the right frontal lobe. Conclusions: In this study, impairments of higher cognitive functions were observed in the context of PFS. They varied in severity and composition between children with symptoms fitting into the spectrum of the Cerebellar Cognitive Affective Syndrome. SPECT scan findings suggest that these impairments are secondary to supratentorial metabolic hypofunction following cerebellar surgery.