Children With Intracranial Arachnoid Cysts: Classification and Treatment

Abstract

We performed a dynamic study of arachnoid cysts (ACs) using magnetic resonance cisternography (MRC) and proposed a classification of ACs.Twenty-three suitable patients in our hospital entered into this study according to our inclusion criteria. MRC images were collected in all the subjects at 1 and 24 hours after the administration of intrathecal gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA). We allocate the enrolled patients into 2 groups, MRC group and surgery group. The MRC results were considered before treatment in 1 group (MRC group, 13 patients), whereas another group was surgically treated without considering the MRC results (surgery group, 10 patients). We calculated the enhanced area of cyst using modified MacDonald Criteria from the images and measured the surrounding subarachnoid area as the reference.We found that it was practically useful to quantify 3 types of ACs, complete communicating, incomplete communicating, and noncommunicating, according to MRC results in this study. All the subjects in both groups are closely observed before the treatment and the follow-up using the MRI examination. In the surgery group, 5 patients were found that the area of cysts shrank in the follow-up stage. However, there was no significant difference in the percentage shrinkage area between the 2 groups.We concluded that MRC with Gd-DTPA as a contrast agent is of significant clinical value for the diagnosis and treatment of children with intracranial ACs. This classification based on dynamic MRC is useful for making surgical recommendations.

FIGURE 1

Modified MacDonald method to measure cyst volumes.

FIGURE 2

AC in the cistern magna of an 11-year-old male. An arachnoid cyst located in the cistern magna was unexpectedly found during CT after a head injury. The cyst did not cause any symptoms. One hour after cisternography, the cyst was enhanced in the sagittal T1 sequence (B). Sagittal T1 at 24 hours showed the signal inside the cyst was equal to the surrounding cistern, indicating a complete communicating AC (C). AC = arachnoid cyst, CT = computed tomography.

FIGURE 3

Arachnoid cyst (AC) in the left middle fossa of a 1.5-year-old male. The patient presented with a left temporal bone eminence without other symptoms. One hour after contrast injection, sagittal T1 demonstrated enhancement of the surrounding cistern instead of the cyst (B). Axial T1 at 24 hours showed a higher signal inside the cyst than that in the lateral ventricle, suggestive of incomplete communicating AC (C).

FIGURE 4

Arachnoid cyst (AC) in the cistern magna of a male 1 year and 3 months of age. The patient presented with retardation of motor development. Physical examination revealed that the muscle force of the lower limbs was grade IV. One hour after contrast injection, sagittal T1 showed imaging of the 4th ventricle and the spinal subarachnoid space and no immediate imaging of the cyst (B). Sagittal T1 at 24 hours showed imaging of the 4th ventricle and the subarachnoid space surrounding the cyst. As the signal of the cyst was lower than the cistern and ventricle, he was diagnosed with noncommunicating AC (C).