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Cognition in Pediatric Chiari Malformation Type 1 Before and After Posterior Fossa Decompression
Tomas Adolfsson1, Erik Edström1, Jenny Pettersson Segerlind2
1Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
Insights
Chiari malformation type 1 (CM1) surgery significantly improved cognitive abilities in children. Postoperative assessments revealed enhancements in overall cognition, visuospatial skills, and executive functions, suggesting neurosurgery benefits beyond symptom relief.
Area of Science:
- Pediatric Neurosurgery
- Neurodevelopmental Disorders
- Cognitive Neuroscience
Background:
- Chiari malformation type 1 (CM1) involves hindbrain structural changes.
- Diagnosis relies on cerebellar tonsil descent below the foramen magnum.
- While often asymptomatic, CM1 can present with headaches and neurological deficits, with cognitive impacts less explored.
Purpose of the Study:
- To investigate cognitive symptoms in children with CM1.
- To evaluate the impact of posterior fossa decompression surgery on cognitive function in pediatric CM1 patients.
Main Methods:
- Cognitive assessments were performed on 11 pediatric CM1 patients before and after surgery.
- Standardized tests included WISC-V, BNT, RAVLT, FAS, and RCFT.
- Preoperative and postoperative cognitive data were compared.
Main Results:
- Preoperative cognitive function was generally within average ranges, with exceptions in picture naming.
- Significant improvements were observed post-surgery in global cognitive ability, visuospatial skills, nonverbal reasoning, and processing speed.
- Executive functions and visuospatial memory also showed significant gains.
Conclusions:
- Pediatric CM1 patients demonstrated average cognitive performance pre-surgery.
- Posterior fossa decompression led to significant cognitive improvements in several domains.
- These findings may inform surgical decision-making for CM1 management in children.
Objective:
Chiari malformation type 1 (CM1) is a condition that affects the hindbrain. The diagnosis is based on the radiologic finding of a descent of the cerebellar tonsils 5 mm or more below the level of the foramen magnum. Although often asymptomatic, CM1 can cause occipital headache or neurologic symptoms. Cognitive symptoms in patients with CM1 have not been explored extensively. This study aimed to fill the knowledge gap regarding cognitive symptoms in children with CM1 and the effects of neurosurgery on these symptoms.
Method:
Eleven consecutive pediatric surgical patients with CM1, without known comorbidities (mean age, 11 years), were evaluated cognitively before and after posterior fossa decompression. The assessments included the Wechsler Scales of Intelligence in Children, fifth edition (WISC-V), Boston Naming Test (BNT), Rey Auditory Verbal Learning Test (RAVLT), verbal fluency test (FAS), and Rey Complex Figure Test (RCFT). Results from preoperative and postoperative tests were compared.
Results:
All presurgical results, except for picture naming, were within the average range. However, significant postsurgical improvements were observed in overall cognitive ability, visuospatial skills, nonverbal logical reasoning, and processing speed. Significant improvements also were found in executive functions and visuospatial memory.
Conclusions:
The children in this study scored within the average range on cognitive tests before surgery compared to age-adjusted norms. After surgery, the test results improved significantly in several domains or remained stable at the preoperative level. These findings are important and could influence surgical decisions for children with CM1.
