PMC6935965_01
Chiari 1 malformation with presyrinx. Magnetic resonance imaging of the brain and spine demonstrate Chiari I malformation (CM-I) with tonsillar herniation 7 mm below the craniocervical junction. The cervical spinal cord is swollen from C2 to C6 with evidence of T2 (a) and T1 (b) signal elongation consistent with presyrinx. (c) Phase-contrast cerebrospinal fluid (CSF) flow study shows attenuation of CSF flow in the dorsal high cervical cord at the site of CM-I, which is preserved in the ventral spinal canal. (d) The remainder of the neuroaxis appeared normal without evidence of cavitation or syrinx.
SNI-10-253-g001.jpg
PMC6935965_01_SNI-10-253-g001.jpg
F1
The magnetic resonance imaging (MRI) of the brain showed that the ventricles were of normal size without hydrocephalus [Figures 1a-d]. The brain and cervical MR studies, however, showed crowding of the craniocervical/cervicomedullary junction with cerebellar tonsillar descent of 7 mm below McRae's line [Figure 1a and b]. Phase-contrast cerebrospinal fluid flow studies revealed significantly reduced flow through the cerebral aqueduct [Figure 1c]. In addition, there was swelling of the cervical cord (on T1 and T2 images) from C2 to C6 consistent with cord edema (e.g., central cord injury) without bony or soft tissue trauma [Figures 1a and b].
Resolution of presyrinx after surgery. One-month after bone-only posterior fossa decompression, magnetic resonance imaging of the cervical spine shows a similar degree of Chiari I malformation with tonsillar descent. However, the previously observed cervical spinal cord swelling and presyrinx have completely resolved. No other abnormality is observed.
SNI-10-253-g002.jpg
PMC6935965_01_SNI-10-253-g002.jpg
F2
Further, the repeat MRI demonstrated total resolution of the cervical presyrinx, although the original CM-I remained stable without a change in tonsillar position [Figure 2].