Jo Verhoeven

The cerebellum: Its role in language and related cognitive and affective functions

The traditional view on the cerebellum as the sole coordinator of motor function has been substantially redefined during the past decades. Neuroanatomical, neuroimaging and clinical studies have extended the role of the cerebellum to the modulation of cognitive and affective processing. Neuroanatomical studies have demonstrated cerebellar connectivity with the supratentorial association areas involved in higher cognitive and affective functioning, while functional neuroimaging and clinical studies have provided evidence of cerebellar involvement in a variety of cognitive and affective tasks. This paper reviews the recently acknowledged role of the cerebellum in linguistic and related cognitive and behavioral-affective functions. In addition, typical cerebellar syndromes such as the cerebellar cognitive affective syndrome (CCAS) and the posterior fossa syndrome (PFS) will be briefly discussed and the current hypotheses dealing with the presumed neurobiological mechanisms underlying the linguistic, cognitive and affective modulatory role of the cerebellum will be reviewed.

A role for the cerebellum in motor speech planning: Evidence from foreign accent syndrome

A 3 year follow-up study was performed in a patient with foreign accent syndrome (FAS) as the sole cognitive manifestation of a left fronto-parietal stroke. The hypothesis of involvement of the right cerebellum in this motor speech planning disorder was investigated by means of functional neuroimaging (SPECT) and neurobehavioral assessments. Based on the close parallelism between the evolution of FAS symptoms and the perfusional changes in the right cerebellum, it is argued that FAS may result from a disruption of a close functional interplay between the supra- and infratentorial speech centers involved in motor speech planning.

Developmental Foreign Accent Syndrome: Report of a New Case

This paper presents the case of a 17-year-old right-handed Belgian boy with developmental FAS and comorbid developmental apraxia of speech (DAS). Extensive neuropsychological and neurolinguistic investigations demonstrated a normal IQ but impaired planning (visuo-constructional dyspraxia). A Tc-99m-ECD SPECT revealed a significant hypoperfusion in the prefrontal and medial frontal regions, as well as in the lateral temporal regions. Hypoperfusion in the right cerebellum almost reached significance. It is hypothesized that these clinical findings support the view that FAS and DAS are related phenomena following impairment of the cerebro-cerebellar network.

Cerebellar involvement in motor speech planning: some further evidence from foreign accent syndrome.

Background: Foreign accent syndrome (FAS) is a rare speech disorder that usually follows from damage to the motor speech areas of the language-dominant hemisphere. Recently, a vascular FAS patient was reported in whom a close parallelism was found between the infratentorial perfusional changes on SPECT and the regression of FAS symptoms. Based on the correlation between the near remission of a right cerebellar hypoperfusion and the near remission of FAS, it was hypothesized that the ‘linguistic cerebellum’ might be involved in the pathogenesis of motor speech planning disorders [Clin Neurol Neurosurg 2006;108:518–522]. Aim: In this article the presumed role of the cerebellum in FAS is further investigated on the basis of an additional FAS case. Methods: Phonetic, neurobehavioral and neuroimaging data were analyzed and clinical-anatomical correlations were investigated. Results: In both patients, a close correspondence was found between the neurolinguistic findings and the functional neuroimaging data. 99mTc ECD SPECT follow-up studies demonstrated that clinical recovery of FAS symptoms was accompanied by a remission of a right cerebellar hypoperfusion. Conclusion: The present study, in which the data of a new FAS patient are discussed, corroborates the view that FAS may follow disruption of a close functional interplay between the supra- and infratentorial motor speech centers.

Consensus Paper: Cerebellum and Emotion

Over the past three decades, insights into the role of the cerebellum in emotional processing have substantially increased. Indeed, methodological refinements in cerebellar lesion studies and major technological advancements in the field of neuroscience are in particular responsible to an exponential growth of knowledge on the topic. It is timely to review the available data and to critically evaluate the current status of the role of the cerebellum in emotion and related domains. The main aim of this article is to present an overview of current facts and ongoing debates relating to clinical, neuroimaging, and neurophysiological findings on the role of the cerebellum in key aspects of emotion. Experts in the field of cerebellar research discuss the range of cerebellar contributions to emotion in nine topics. Topics include the role of the cerebellum in perception and recognition, forwarding and encoding of emotional information, and the experience and regulation of emotional states in relation to motor, cognitive, and social behaviors. In addition, perspectives including cerebellar involvement in emotional learning, pain, emotional aspects of speech, and neuropsychiatric aspects of the cerebellum in mood disorders are briefly discussed. Results of this consensus paper illustrate how theory and empirical research have converged to produce a composite picture of brain topography, physiology, and function that establishes the role of the cerebellum in many aspects of emotional processing.

APRAXIC AGRAPHIA FOLLOWING A RIGHT CEREBELLAR HEMORRHAGE

Apraxic agraphia follows disruption of skilled movement plans of writing and is characterized by distorted, hesitant, incomplete, and imprecise letter formation. The causative lesion is located in the superior parietal lobe (storage of graphomotor plans) or the dorsolateral and medial part of prefrontal cortex (conversion of graphomotor plans to motor commands).1 Recently, the condition was also reported after left dorsomedial thalamic infarction with reduced oxygen metabolism in left premotor areas.2 ### Case report. A 72-year-old right-handed engineer acutely developed postural instability and gait disturbances. Neurologic examination showed a pure cerebellar deficit with distinct midline cerebellar dysfunction and less pronounced right appendicular ataxia. Apart from implantation of a pacemaker for sick sinus syndrome, his medical history was unremarkable. CT scan of the brain disclosed a hemorrhagic lesion in the right cerebellar hemisphere involving cortex and the medullary core (figure 1A). No supratentorial lesions were detected by repeat CT at 3 and 6 months after onset. Figure 1 CT scan and quantified Tc-99m-ethyl cysteinate dimer SPECT studies CT scan of the brain disclosing a hemorrhage in the right cerebellar hemisphere involving cortex and the medullary core (A). Quantified Tc-99m-ethyl cysteinate dimer SPECT studies conducted …

A Foreign Speech Accent in a Case of Conversion Disorder

Objective: The aim of this paper is to report the psychiatric, neuroradiological and linguistic characteristics in a native speaker of Dutch who developed speech symptoms which strongly resemble Foreign Accent Syndrome. Background: Foreign Accent Syndrome is a rare speech production disorder in which the speech of a patient is perceived as foreign by speakers of the same speech community. This syndrome is generally related to focal brain damage. Only in few reported cases the Foreign Accent Syndrome is assumed to be of psychogenic and/or psychotic origin. Method: In addition to clinical and neuroradiological examinations, an extensive test battery of standardized neuropsychological and neurolinguistic investigations was carried out. Two samples of the patients spontaneous speech were analysed and compared to a 500,000-words reference corpus of 160 normal native speakers of Dutch. Results: The patient had a prominent French accent in her pronunciation of Dutch. This accent had persisted over the past eight years and has become progressively stronger. The foreign qualities of her speech did not only relate to pronunciation, but also to the lexicon, syntax and pragmatics. Structural as well as functional neuroimaging did not reveal evidence that could account for the behavioural symptoms. By contrast psychological investigations indicated conversion disorder. Conclusions: To the best of our knowledge this is the first reported case of a foreign accent like syndrome in conversion disorder.

Developmental Coordination Disorder: Disruption of the Cerebello-Cerebral Network evidenced by SPECT

Little is known about the neurobiological substrate of developmental coordination disorder (DCD), a neuro-developmental syndrome with significant, negative impact on the motor, cognitive and affective level throughout lifespan. This paper reports the clinical, neurocognitive and neuroradiological findings of a 19-year-old patient with typical DCD. As demonstrated by mild ataxia and a close semiological correspondence with the recently acknowledged ‘cerebellar cognitive affective syndrome’, clinical and neurocognitive investigations unambiguously indicated functional disruption of the cerebellum. Structural MRI of the brain confirmed cerebellar involvement revealing a slight anterior/superior asymmetry of vermal fissures consistent with rostral vermisdysplasia. Although this abnormality of vermal fissuration is generally considered an incidental neuroradiological finding without any clinical relevance, a potentially subtle impact on the developmental level has never been formally excluded. In addition to a generally decreased perfusion of the cerebellum, a quantified Tc-99m-ECD SPECT disclosed functional suppression of the anatomoclinically suspected supratentorial regions involved in the execution of planned actions, visuo-spatial processing and affective regulation. Based on these findings, it is hypothesised that the cerebellum is crucially implicated in the pathophysiologcial mechanisms of DCD, reflecting disruption of the cerebello-cerebral network involved in the execution of planned actions, visuo-spatial cognition and affective regulation.

Neurogenic foreign accent syndrome: articulatory setting, segments and prosody in a Dutch speaker

Foreign accent syndrome (FAS) can be defined as a motor speech disorder in which patients develop a speech accent which is notably different from their premorbid habitual accent. This paper aims to provide an explicit description of the neurolinguistic and phonetic characteristics of a female speaker of Belgian Dutch who suffered from neurogenic FAS in which she developed a French/German foreign accent after a left hemisphere stroke. A detailed phonetic analysis of the speaker’s pronunciation errors revealed problems at both the segmental and suprasegmental level. At the segmental level a wide variety of pronunciation errors were observed which are consistent with a tense articulatory setting: creaky voice, strengthening of fricatives into stops and more carefully articulated consonants and vowels. The data suggest that the perception of the French accent may have resulted from a combination of speech pathology features and unaffected regional pronunciation characteristics of the patient’s Standard Dutch. In contrast to the traditional view in the literature that FAS represents a primary dysprosodic disturbance, a detailed analysis of the speaker’s intonation contours by means of the stylization method revealed the entirely correct implementation of the most common pitch contours of Standard Dutch. This unique finding shows that FAS does not by definition follow from disruption of prosodic processing. However, the frequency of occurrence of the different types of pitch contours was clearly deviant since the patient very frequently used the Dutch continuation rise. It is hypothesized that this might represent a deliberate strategy of the speaker to stay in control of the speaking situation by keeping the speaking turn which she is at continuous risk of losing as the result of long and frequent pausing.

Belgian standard Dutch

Dutch is a language spoken by about 20 million people in the Netherlands and Belgium. This region is not only characterised by a complex dialect situation, but also by the use of two institutionalised varieties of the Standard language: Netherlandic Dutch is spoken in the Netherlands and is documented in Collins & Mees (1982), Mees & Collins (1983) and Gussenhoven (1999), while Belgian Dutch is spoken in the northern part of Belgium (Flanders) by approximately 6 million speakers. This variety is the same as what is commonly referred to internationally as ‘Flemish’. However, the term ‘Flemish’ is avoided here since it erroneously suggests that this language is different from the one spoken in the Netherlands: the lexical and syntactic differences between the two language varieties are very small. Nevertheless, there are significant phonetic differences as well as substantial regional variability within the two speech communities.