From the Research
Asymptomatic Chiari Malformation in Adults
- Many individuals with Chiari I malformation do not become symptomatic until adulthood, and some may remain asymptomatic throughout their lives 1, 2, 3, 4, 5
- Studies have shown that most asymptomatic individuals with Chiari malformation type 1 (CM-1) remain asymptomatic, even in the presence of syringomyelia 3
- The natural history of mild symptomatic and asymptomatic CM-1 in adults is relatively benign and nonprogressive 3
- Asymptomatic CM-1 can be diagnosed incidentally, and its prevalence is estimated to be approximately 1% 4
Diagnosis and Management
- Magnetic resonance imaging (MRI) is the gold standard investigative modality for diagnosing Chiari malformation, showing cerebellar tonsillar descent 5 mm or more below the foramen magnum 4
- The management of CM-1 is variable and sometimes controversial, with surgery usually reserved for patients with disabling headaches or neurological deficits from the syrinx 4
- The approach to patients with CM-1 should be multidisciplinary, and the first step in management is phenotyping the symptoms, as they may be due to other pathologies 4
Special Considerations
- Minor head or neck trauma can precipitate the onset of symptoms in a small number of previously asymptomatic patients with Chiari I malformation 1
- The management of CM-1 during pregnancy, restriction to lifestyle related to athletic activities, and the coexistence of hypermobility require special considerations 4