Cognitive dysfunction in patients with Chiari malformation type 1 and its relationship with the degree of cerebellar tonsil ectopia

Abstract

The use of neuroimaging diagnostics of Chiari malformation type 1 (CM1) allows us to expand our understanding of both the spectrum of clinical manifestations of the anomaly and its radiological characteristics. New approaches in the study of the CM1 symptom complex include cognitive dysfunction and the mechanisms of its formation. Of great research interest is the previously unexplored relationship of cognitive dysfunction in patients with CM1 with different degree of tonsils ectopia. Objective : to identify the features of the cognitive status in patients with CM1 and to assess the relationship of CM1 with the degree of cerebellar tonsil ectopia. Patients and methods . The study included 110 adult patients with CM1 aged 25.61±6.9 years. The control group consisted of 50 people aged 26.36±5.0 years without signs of CM1 and other organic brain pathology. The assessment of neuroimaging parameters was carried out on a magnetic resonance tomograph with a magnetic field induction of 1.5 T. Cognitive status was assessed using the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA) and the Trail Making Test (TMT; subtests A and B – TMTA, TMTB). Results and discussion . When assessing the cognitive status of patients with СM1 and those of the control group, statistically significant differences were determined in the domains of executive functioning, visuospatial skills, attention, delayed recall, and speech. All patients, regardless of the degree of cerebellar tonsil ectopia, had lower cognitive performance compared to the control group. There was a trend towards an increase in cognitive deficit with an increase in the degree of ectopia of the cerebellar tonsils. The most pronounced cognitive deficit with a significant decrease in the domains of executive functioning, visuospatial skills, attention, delayed recall and speech was noted in a subgroup of patients with a high degree of tonsil ectopia. Conclusion . The presence of a specific cognitive deficit in patients with СM1 was revealed, and a significant relationship between cognitive dysfunction and the degree of cerebellar tonsil ectopia was established.