The study included 60 of primary HFS patients and 60 healthy controls matched by age. AH was defined according to WHO criteria. The vessel compression of the brainstem was measure on MRI scans in selected region of vasomotor center located in the ventro-lateral medulla (VLM), between the pontomedullary junction, retro-olivary sulcus and the root entry zone (REZ) of the IX and X nerves. Modeling and compression severity of the VLM was graded in the 0–3 scale.
The prevalence of AH in HFS patients did not differ significantly from the control group (61.6% vs 45.0%, p = ns). VML compression by vessel was frequently found in HFS patients with AH than without AH (97.2% vs 60.9%, χ2 = 11.0, p = 0.0009). A similar relation was also found in the control group. The higher rate of VML vascular compression was related to the presence of AH in both, HFS patients and control group.
The prevalence of AH in HFS patients does not differ from controls. The VLM compression in HFS patients and controls is related to AH diagnosis. The association between AH and VLM compression is stronger in patients with higher degree of VLM compression.