Comparison between decompressed and non-decompressed Chiari Malformation type I patients: A neuropsychological study

Background: Previous studies have suggested an association of Chiari Malformation type I (CM-I) and cognitive deficits. CM-I is a neurological disorder characterized by a descent of cerebellar tonsils into the foramen magnum, resulting in overcrowding of the upper cervical spine region. Posterior fossa decompression (PFD) is the surgical treatment of choice, however, the literature on the consequences for patients is mainly reduced to the assessment of physical symptoms. Methods: Data from a neuropsychological assessment of 76 patients with CM-I, both with PFD (n = 37) and without PFD (n = 39) surgery, and 76 healthy controls, matched by gender, age and years of education are reported. Results: CM-I patients show a generally lower cognitive performance in executive function, verbal fluency, spatial cognition, language (naming), verbal memory, processing speed, emotional facial recognition and theory of mind, compared to control group. The results are maintained even after statistically controlling for the influence of perceived physical pain and the presence of anxious-depressive symptomatology. Data also illustrate a similar cognitive profile between both groups with CM-I. Conclusion: These findings provide evidence of a deficient cognitive profile associated with CM-I, regardless of the PFD surgery. According to these results, both physical and cognitive consequences must be considered in the treatment of CM-I.