Posterior fossa syndrome (PFS) due to vascular etiology is rare in children and adults. To the best of our knowledge, PFS due to cerebellar stroke has only been reported in patients who also underwent surgical treatment of the underlying vascular cause. We report longitudinal clinical, neurocognitive and neuroradiological findings in a 71-year-old right-handed patient who developed PFS following a right cerebellar haemorrhage that was not surgically evacuated. During follow-up, functional neuroimaging was conducted by means of quantified Tc-99m-ECD SPECT studies. After a 10-day period of akinetic mutism, the clinical picture developed into cerebellar cognitive affective syndrome (CCAS) with reversion to a previously learnt accent, consistent with neurogenic foreign accent syndrome (FAS). No psychometric evidence for dementia was found. Quantified Tc-99m-ECD SPECT studies consistently disclosed perfusional deficits in the anatomoclinically suspected but structurally intact bilateral prefrontal brain regions. Since no surgical treatment of the cerebellar haematoma was performed, this case report is presumably the first description of pure, "non-surgical vascular PFS". In addition, reversion to a previously learnt accent which represents a subtype of FAS has never been reported after cerebellar damage. The combination of this unique constellation of poststroke neurobehavioural changes reflected on SPECT shows that the cerebellum is crucially implicated in the modulation of neurocognitive and affective processes. A decrease of excitatory impulses from the lesioned cerebellum to the structurally intact supratentorial network subserving cognitive, behavioural and affective processes constitutes the likely pathophysiological mechanism underlying PFS and CCAS in this patient.
BackgroundCerebellar mutism syndrome (CMS) or posterior fossa syndrome (PFS) consists of a constellation of neuropsychiatric, neuropsychological and neurogenic speech and language deficits. It is most commonly observed in children after posterior fossa tumor surgery. The most prominent feature of CMS is mutism, which generally starts after a few days after the operation, has a limited duration and is typically followed by motor speech deficits. However, the core speech disorder subserving CMS is still unclear.Case presentationThis study investigates the speech and language symptoms following posterior fossa medulloblastoma surgery in a 12-year-old right-handed boy. An extensive battery of formal speech (DIAS = Diagnostic Instrument Apraxia of Speech) and language tests were administered during a follow-up of 6 weeks after surgery. Although the neurological and neuropsychological (affective, cognitive) symptoms of this patient are consistent with Schmahmann’s syndrome, the speech and language symptoms were markedly different from what is typically described in the literature. In-depth analyses of speech production revealed features consistent with a diagnosis of apraxia of speech (AoS) while ataxic dysarthria was completely absent. In addition, language assessments showed genuine aphasic deficits as reflected by distorted language production and perception, wordfinding difficulties, grammatical disturbances and verbal fluency deficits.ConclusionTo the best of our knowledge this case might be the first example that clearly demonstrates that a higher level motor planning disorder (apraxia) may be the origin of disrupted speech in CMS. In addition, identification of non-motor linguistic disturbances during follow-up add to the view that the cerebellum not only plays a crucial role in the planning and execution of speech but also in linguistic processing. Whether the cerebellum has a direct or indirect role in motor speech planning needs to be further investigated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.