Chiari malformation is a serious neurological disorder where the bottom part of the brain (cerebellar tonsils
) descend into the foramen magnum, crowding the brainstem/spinal cord and altering CSF flow dynamics, producing many disabling symptoms.
investigated the position of the cerebellar tonsils
relative to the foramen magnum and the position of the iter relative to the incsiural line in 7 patients with IH, comparing them to normative data from Reich et al.
The cerebellar tonsils
were also prominent, without definite herniation.
However, hypoglycemia recurred with dysarthria after two months and was attributed to displacement of the cerebellar tonsils
, due to an epidural patch failure.
Pathophysiology of syringomielia associated with Chiari I malformation of the cerebellar tonsils
. Journal of Neurosurgery, 80, 3-15.
Caption: Figure 1: MRI of the brain shows Chiari malformation type 1 with herniation of the cerebellar tonsils
beneath the foramen magnum of 17 mm and adenoid hypertrophy.
In this case the cerebellar tonsils
were herniating through the foramen magnum when the imaging study was done.
Chiari I malformation is characterized by low-lying cerebellar tonsils
In addition, although decompression surgery of the cerebellar tonsils
is indicated as an effective treatment of the syringomyelia-Chiari I complex, resulting in the regression of symptoms during the immediate postoperative period or clinical improvement in 78% of cases , in the present study surgery did not result in clinical improvement and aggravation of the symptoms was observed.
Chiari malformation occurs when part of the brain (the cerebellar tonsils
) protrudes down out of the bottom of the skull and crowds the top of the spinal cord.
Spontaneous CSF leaks also can cause generalized sagging of the brain with downward displacement of the cerebellar tonsils
that is clearly visible on MRI with gadolinium.
There may also be descent of the cerebellar tonsils
, obliteration of prepontine, perichiasmatic cisterns, flattening of the optic chiasm, crowding of the posterior fossa, as well as decreased ventricular size, according to Dr.