Cerebellar mutism

Cerebellar mutism occurs in about 25% of children following posterior fossa tumor surgery. It is usually accompanied by other neurological and behavioral disturbances. Mutism is transient in nature lasting several days to months and is frequently followed by dysarthria. In addition, impairment of language and other neuropsychological functions can be found after long term follow up in the majority of patients. The pathophysiological background of mutism may be higher speech dysfunction mediated by crossed cerebello-cerebral diaschisis which is frequently found during the mute period. Foremost injury to the bilateral dentatothalamocortical tract appears to be critical for the development of cerebello-cerebral diaschisis and subsequent mutism. Direct cerebellar injury is the likely reason for persisting deficits after the mute period. Minimization of injury to the dentatothalamocortical tract during surgery may be promising in the prevention of mutism. While there is no established treatment of mutism, early speech and rehabilitation therapy is recommended.     

Pediatric traumatic brain injury: Language outcomes and their relationship to the arcuate fasciculus

Pediatric traumatic brain injury (TBI) may result in long-lasting language impairments alongside dysarthria, a motor-speech disorder. Whether this co-morbidity is due to the functional links between speech and language networks, or to widespread damage affecting both motor and language tracts, remains unknown.     

Speech motor deficits in cerebellar infarctions

Functional imaging studies demonstrated cerebellar activation during speech movements in the rostral cerebellar region. Ischemic lesions of this area, which is supplied by the superior cerebellar artery, induce dysarthria.     

Role of cerebellum in fine speech control in childhood: persistent dysarthria after surgical treatment for posterior fossa tumour

Dysarthria following surgical resection of childhood posterior fossa tumour (PFT) is most commonly documented in a select group of participants with mutism in the acute recovery phase, thus limiting knowledge of post-operative prognosis for this population of children as a whole. Here we report on the speech characteristics of 13 cases seen long-term after surgical treatment for childhood PFT, unselected for the presence of post-operative mutism (mean time post-surgery = 6y10 m, range 1;4-12;6 years, two had post-operative mutism), and examine factors affecting outcome. Twenty-six age- and sex- matched healthy controls were recruited for comparison. Participants in both groups had speech assessments using detailed perceptual and acoustic methods. Over two-thirds of the group (69%) with removal of PFT had a profile of typically mild dysarthria. Prominent speech deficits included consonant imprecision, reduced rate, monopitch and monoloudness. We conclude that speech deficits may persist even up to 10 years post-surgery in participants who have not shown mutism in the acute phase. Of cases with unilateral lesions, poorer outcomes were associated with right cerebellar tumours compared to left, consistent with the notion based on adult data that speech is controlled by reciprocal right cerebellar/left frontal interactions. These results confirm the important role of the cerebellum in the control of fine speech movements in children.     

Speech motor programming in hypokinetic and ataxic dysarthria

It is widely accepted that the cerebellar and basal ganglia control circuits contribute to the programming of movement. Converging evidence from neuroimaging, limb control, and neuropsychological studies suggests that (1) people with cerebellar disease have reduced ability to program movement sequences in advance of movement onset and (2) people with Parkinson's disease are unable to maintain a programmed response or to rapidly switch between responses. Despite a substantial supporting literature, no studies have addressed these potential areas of speech programming disruption for speakers with ataxic and hypokinetic dysarthria. Control participants and adults with dysarthria completed speech reaction time protocols designed to capture these aspects of utterance preparation. Results provided initial support for processing deficits in speakers with ataxic and hypokinetic dysarthria that are separable from motor execution impairments.