Clinical and methodological confounders in assessing the cerebellar cognitive affective syndrome in adult patients with posterior fossa tumours

Abstract

The cerebellar cognitive affective syndrome (CCAS) was first described by Schmahmann and Sherman as a constellation of symptoms including dysexecutive syndrome, spatial cognitive deficit, linguistic deficits and behavioural abnormalities in patients with a lesion in the cerebellum with otherwise normal brain. Neurosurgical patients with cerebellar tumours constitute one of the cohorts in which the CCAS has been described. In this paper, we present a critical review of the literature of this syndrome in neurosurgical patients. Thereafter, we present a prospective clinical study of 10 patients who underwent posterior fossa tumour resection and had a detailed post-operative neuropsychological, neuropsychiatric and neuroradiological assessment. Because our findings revealed a large number of perioperative neuroradiological confounding variables, we reviewed the neuroimaging of a further 20 patients to determine their prevalence. Our literature review revealed that study design, methodological quality and sometimes both diagnostic criteria and findings were inconsistent. The neuroimaging study (pre-operative, n = 10; post-operative, n = 10) showed very frequent neuroradiological confounding complications (e.g. hydrocephalus; brainstem compression; supratentorial lesions and post-operative subdural hygroma); the impact of such features had largely been ignored in the literature. Findings from our clinical study showed various degree of deficits in neuropsychological testing (n = 1, memory; n = 3, verbal fluency; n = 3, attention; n = 2, spatial cognition deficits; and n = 1, behavioural changes), but no patient had full-blown features of CCAS. Our study, although limited, finds no robust evidence of the CCAS following surgery. This and our literature review highlight a need for guidelines regarding study design and methodology when attempting to evaluate neurosurgical cases with regard to the potential CCAS.

A case of cerebellar cognitive affective syndrome following left paramedian cerebellar tumor

“…The association of cerebellar dysfunction to cognitive, affective, and perceptual disturbances, although not a new concept is making its way back in relatively new literature [8]. The present case provides further support for the association of cerebellar dysfunction with disturbances in affect, perception and cognition [9][10][11][12][13][14][15][16][17][18].…”

Long-term supratentorial brain structure and cognitive function following cerebellar tumour resections in childhood

“…Studies aimed at investigating the cognitive role of the cerebellum critically rely on the assumption that resection of cerebellar tissue is the main causal factor explaining structural and cognitive outcomes. If hydrocephalus were to emerge as a more likely primary mechanism, conclusions based on these previous studies would need to be reevaluated (Aarsen et al, 2014;Omar et al, 2014). Therefore, our second aim was to investigate possible mechanisms underlying any group differences by assessing the unique contribution of hydrocephalus severity and cerebellar lesion volumes, respectively.…”

The Cerebellar Cognitive Affective Syndrome—a Meta-analysis

“…Some studies include children, thereby not differentiating between the CCAS and postoperative paediatric Cerebellar Mutism Syndrome (ppCMS) (11,12). Others include patients with cerebellar pathologies extending to the cerebrum, preventing any correlations between cerebellar structure and neuropsychological function (2,5,(13)(14)(15). Third, neuropsychological tests are not routinely performed in every patient with a cerebellar disorder.…”