Metalinguistic Deficits in Patients with Cerebellar Dysfunction: Empirical Support for the Dysmetria of Thought Theory

Abstract

The cerebellar cognitive affective syndrome (CCAS) includes disruption of linguistic processing such as verbal fluency, verbal working memory, grammar, and speech perception. We set out to examine linguistic capabilities in patients with cerebellar lesions to determine which domains are spared and which impaired and to evaluate the underlying cognitive structure of these deficits. Forty-four patients with cerebellar disease were compared to 40 healthy controls on the Oral Sentence Production Test (OSPT) which assesses production of sentences with correct syntactic structure and semantic quality. Twenty-five of these cerebellar patients and 25 controls received the Test of Language Competence-Expanded (TLC-E) that assesses metalinguistic ability. The OSPT failed to reveal differences between patients and controls. In contrast, all cerebellar patients were impaired on each of the four TLC-E subtests. Differences between isolated cerebellar and complex cerebrocerebellar patients were nonsignificant. These results confirm and extend prior observations of the TLC-E in patients with cerebellar lesions and suggest three separate but related language impairments following cerebellar dysfunction: (1) disruption in automatic adjustment of intact grammatical and semantic abilities to a linguistic context in sentence production, (2) disruption in automatic adjustment to a linguistic context in sentence interpretation, and (3) disruption of cognitive processes essential for linguistic skills, such as analysis and sequential logical reasoning. These findings are consistent with the unifying framework of the universal cerebellar transform and the dysmetria of thought theory and provide new insights into the nature of the cognitive impairments in patients with the CCAS.

The largest caucasian kindred with dentatorubral‐pallidoluysian atrophy: A founder mutation in italy

“…34 The peculiar cognitive and behavioral profile in this DRPLA pedigree reflects "dysmetria of thought," which is a key element of cerebellar cognitive-affective syndrome. [35][36][37][38] Neuroimaging in these DRPLA patients demonstrated atrophy of the cerebellum and midbrain at all ages, confirming the presence of cerebral Caucasians matter lesions only in adult and elderly patients 6 ( Supplementary Table 4).…”

“…The qualitative analysis of drawing indicated by the Qualitative Scoring MMSE Pentagon Test score of the MMSE pentagon copy task also suggested semantic deficits related to the degradation of the mental representation of the figure, rather than graphic visuoperceptual difficulties . The peculiar cognitive and behavioral profile in this DRPLA pedigree reflects “dysmetria of thought,” which is a key element of cerebellar cognitive‐affective syndrome …”

Functional Territories of Human Dentate Nucleus

“…Identifying and mapping these macro-scale networks in different brain territories is relevant for the characterization of functional and structural abnormalities in psychopathology (Darby et al 2018, Palaniyappan & Liddle 2012, Whitfield-Gabrieli & Ford 2012, and necessary for the development of targeted brain stimulation interventions (Esterman et al 2017). In the specific case of cerebellar cortex, damage to the cerebellar posterior lobe, which provides inputs to the DN, causes the cerebellar cognitive affective syndrome, characterized by deficits in executive, linguistic, visuospatial and affective processing (Guell et al 2015;Hoche et al 2016Hoche et al , 2018Schmahmann & Sherman 1998, Schmahmann et al 2009, Stoodley et al 2016). In addition, multiple studies have reported cerebellar cortical abnormalities in numerous disorders such as Alzheimer's disease (Guo et al 2016, Jacobs et al 2018, autism spectrum disorder (Arnold Anteraper et al 2018, D'Mello & Stoodley 2015, and schizophrenia (Moberget et al 2018), with preliminary evidence suggesting that cerebellar cortical stimulation might improve symptoms in these diseases (Brady et al 2019, Demirtas-Tatlidede et al 2010, Di Lorenzo et al 2013, Garg et al 2016, Stoodley et al 2017, Tikka et al 2015.…”

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