Cerebellar Motor Function in Spina Bifida Meningomyelocele

Abstract

Spina bifida meningomyelocele (SBM), a congenital neurodevelopmental disorder, involves dysmorphology of the cerebellum, and its most obvious manifestations are motor deficits. This paper reviews cerebellar neuropathology and motor function across several motor systems well studied in SBM in relation to current models of cerebellar motor and timing function. Children and adults with SBM have widespread motor deficits in trunk, upper limbs, eyes, and speech articulators that are broadly congruent with those observed in adults with cerebellar lesions. The structure and function of the cerebellum are correlated with a range of motor functions. While motor learning is generally preserved in SBM, those motor functions requiring predictive signals and precise calibration of the temporal features of movement are impaired, resulting in deficits in smooth movement coordination as well as in the classical cerebellar triad of dysmetria, ataxia, and dysarthria. That motor function in individuals with SBM is disordered in a manner phenotypically similar to that in adult cerebellar lesions, and appears to involve similar deficits in predictive cerebellar motor control, suggests that age-based cerebellar motor plasticity is limited in individuals with this neurodevelopmental disorder.

Functional Plasticity in Childhood Brain Disorders: When, What, How, and Whom to Assess

“…For example, individuals with spina bifida meningomyelocele, who have significant cerebellar dysmorphologies (Juranek et al, 2010; Fig. 3) show preserved motor learning, but impaired motor functions requiring predictive signals and precise calibration of the temporal features of movement (Dennis et al, 2010). Assessing motor prediction is important, even if not often done, because many disorders of the brain involve cerebellar pathology (e.g., Fernandez et al, 2013).…”

“…At age 2, toddlers can remind a caregiver to get ice cream (Somerville et al, 1983), and prospective memory improves into adolescence (Kerns, 2000; Maylor et al, 2010; Yang et al, 2011). Prospective memory may be poor in individuals with spina bifida meningomyelocele even when other forms of memory are not deficient (Dennis et al, 2007; Dennis et al, 2010). Prospective memory is impaired in ADHD (Kerns and Price, 2001) and TBI (McCauley and Levin, 2004; Ward et al, 2004; Ward et al, 2007).…”

Evidence of Cerebellar Dysfunction in Children with Myelomeningocele?

“…They are all weakly correlated to each other but are definitely associated with structural changes in the brain. The variation in the magnitude of these functional deficits is thought to be related to the degree of structural changes in the cerebellum caused by ACM [11,23]. Because of the variation in functional deficits, children with SBM present with a mixed pattern of strengths and weaknesses often within the same areas.…”

“…Furthermore, children with SBM have a preference for looking and attending to left hemispace and to inferior hemispace [41]. Spatial biases have been noted as both a cause and a result of poor motor regulation [11]. Visual attention and function is crucial for later development of cognitive skills in children.…”

“…The anterior cerebellum enlarges while the posterior cerebellum is reduced. Cerebellar pathology plays a central role in causing the motor and perceptual findings in children with SBM [11].…”