CHERI: time to identify the syndrome?

Cognition in Chiari Malformation Type I: an Update of a Systematic Review

Chiari malformation has been classified as a group of posterior cranial fossa disorders characterized by hindbrain herniation. Chiari malformation type I (CM-I) is the most common subtype, ranging from asymptomatic patients to those with severe disorders. Research about clinical manifestations or medical treatments is still growing, but cognitive functioning has been less explored. The aim of this systematic review is to update the literature search about cognitive deficits in CM-I patients. A literature search was performed through the following electronic databases: MEDLINE, PsychINFO, Pubmed, Cochrane Library, Scopus, and Web of Science. The date last searched was February 1, 2023. The inclusion criteria were as follows: (a) include pediatric or adult participants with a CM-I diagnosis, (b) include cognitive or neuropsychological assessment with standardized tests, (c) be published in English or Spanish, and (d) be empirical studies. Articles that did not report empirical data, textbooks and conference abstracts were excluded. After the screening, twenty-eight articles were included in this systematic review. From those, twenty-one articles were focused on adult samples and seven included pediatric patients. There is a great heterogeneity in the recruited samples, followed methodology and administered neurocognitive protocols. Cognitive functioning appears to be affected in CM-I patients, at least some aspects of attention, executive functions, visuospatial abilities, episodic memory, or processing speed. However, these results require careful interpretation due to the methodological limitations of the studies. Although it is difficult to draw a clear profile of cognitive deficits related to CM-I, the literature suggests that cognitive dysfunction may be a symptom of CM-I. This suggest that clinicians should include cognitive assessment in their diagnostic procedures used for CM-I. In summary, further research is needed to determine a well-defined cognitive profile related to CM-I, favoring a multidisciplinary approach of this disorder.

Analysis of Visuospatial Abilities in Chiari Malformation Type I

The involvement of the cerebellum in visuospatial abilities has been evidenced in numerous studies, based on the cerebellar-cortical circuitry. This domain has been evaluated in several patients with cerebellar disorders, but the assessment of visuospatial processing in Chiari malformation type I (CM-I) is scarce. The aim of this study is to analyze the visuospatial performance between CM-I adult patients and healthy controls. Participants have been tested using Block Design and Visual Puzzles subtests of the Wechsler Adult Intelligence Scale (WAIS), the Benton Judgment of Line Orientation test, and the Rey-Osterrieth Complex Figure test. The anxious-depressive symptomatology, the physical pain, and the premorbid intelligence have been controlled for, as well. The CM-I patients showed a significantly lower performance; however, after analyzing and controlling for the effect of clinical variables and psychopathological symptomatology, the main effect was maintained for visual puzzles and line orientation tasks. The findings suggest that CM-I patients show a poorer performance in tasks that require an exercise of perceptual reasoning without motor demand, accompanied by visualization and mental imagery of the stimuli. This study contributes towards the reinforcement of the evidence on the cognitive alterations associated to CM-I.

A Systematic Review of Cognition in Chiari I Malformation

Displacement of the cerebellar tonsils in Chiari type I malformation (CMI) can affect functions controlled by the cerebellum and brainstem. While playing an integral role in the control of movement, the cerebellum also has widespread cortical connections, influencing a range of cognitive process. A systematic literature review was conducted to examine the relationship between cognition and CMI, assessing evidence for general or domain-specific cognitive change. The search protocol examined the AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus databases. Articles meeting the following criteria were included in this review (i) examined children or adults with a clinically defined diagnosis of CMI, (ii) assessed cognitive function with a prospective examination, (iii) included at least one standardized instrument designed to measure general or specific domains of cognitive function, and (iv) were published in English in a peer-reviewed journal. Twelve articles were identified, including 783 cases aged 3 months to 64 years. General cognition, processing speed, and learning and memory appeared less affected, while language deficits appeared to diminish with age. Executive dysfunction was the most commonly reported cognitive impairment, while attention and working memory, and visuospatial and perceptual skills also appeared vulnerable. Numerous methodological limitations were identified that should be considered in interpreting the impact of CMI and planning future investigations. Overall, there is currently insufficient evidence to describe a valid and reliable profile of cognitive impairment in CMI. Further research is required to confirm these preliminary psychometric results and integrate them with pathophysiological models.

Associated disorders of Chiari Type I malformations: a review

A single pathophysiological mechanism of Chiari Type I malformations (CM-I) has been a topic of debate. To help better understand CM-I, the authors review disorders known to be associated with CM-I. The primary methodology found among most of them is deformation of the posterior cranial fossa, usually with subsequent decrease in volume. Other mechanisms exist as well, which can be categorized as either congenital or acquired. In understanding the relationship of such disorders with CM-I, we may gain further insight into the process by which cerebellar tonsillar herniation occurs. Some of these pathologies appear to be true associations, but many appear to be spurious.

Chiari I malformation, delayed gross motor skills, severe speech delay, and epileptiform discharges in a child with FOXP1 haploinsufficiency

Human FOXP2 deficiency has been identified as a cause of hereditary developmental verbal dyspraxia. Another member of the same gene family, FOXP1, has expression patterns that overlap with FOXP2 in some areas of the brain, and FOXP1 and FOXP2 have the ability to form heterodimers. These findings suggest the possibility that FOXP1 may also contribute to proper speech development. However, no such role of FOXP1 has been established to date. Recently, a child was reported who presented with a 3p13-14.1 deletion of four genes, including FOXP1, and a constellation of deficits that included speech delay. In this study, we report the case of a patient with a single deletion of FOXP1. This patient presented with speech and motor developmental delays, a Chiari I malformation, and epileptiform discharges. The nature of the speech deficit is different from the primary oromotor verbal dyspraxia found in patients with FOXP2 deficiency. The patient's developmental deficits may support a role for FOXP1 in the development of verbal and motor skills.