Chiari Malformation Type 1.5
The Chiari Malformation Type 1 is a spectrum that includes some patients who do not fall into the exact category of this entity.
While Chiari Malformation have been categorically recognized as discrete and individual conditions, newer classifications such as CM 0 and CM 1.5 exhibit some degree of continuity with CM 1; however, they require distinct and separate classification as symptoms and treatments can vary among these clinical subtypes 1).
Case reports
A holocord syringomyelia due to Chiari Malformation Type 1.5 in a 12-year-old girl was serially imaged with 3 Tesla MRI over 4 years. The serial MRI showed a reduction in the size of the syrinx, without any surgical intervention or CM improvement, but rather due to spontaneous spinal cord tear. The tear was clearly demonstrated by evidence of flow signal across the tear between syrinx and subarachnoid space at the upper thoracic level. The tear showed spontaneous closure at follow-up. A medullary tear has been described in the adult population as one of the putative causes of spontaneous syringomyelia reduction, but its clear demonstration with modern high-resolution MRI has not been reported in the pediatric population. Moreover, this is the first reported case of syrinx reduction due to spontaneous fissuration in a pediatric patient 2).