Intracranial compliance is associated with symptoms of orthostatic intolerance in chronic fatigue syndrome

Abstract

Symptoms of orthostatic intolerance (OI) are common in Chronic Fatigue Syndrome (CFS) and similar disorders. These symptoms may relate to individual differences in intracranial compliance and cerebral blood perfusion. The present study used phase-contrast, quantitative flow magnetic resonance imaging (MRI) to determine intracranial compliance based on arterial inflow, venous outflow and cerebrospinal fluid flow along the spinal canal into and out of the cranial cavity. Flow-sensitive Alternating Inversion Recovery (FAIR) Arterial Spin Labelling was used to measure cerebral blood perfusion at rest. Forty patients with CFS and 10 age and gender matched controls were scanned. Severity of symptoms of OI was determined from self-report using the Autonomic Symptom Profile. CFS patients reported significantly higher levels of OI (p < .001). Within the patient group, higher severity of OI symptoms were associated with lower intracranial compliance (r = -.346, p = .033) and higher resting perfusion (r = .337, p = .038). In both groups intracranial compliance was negatively correlated with cerebral perfusion. There were no significant differences between the groups in intracranial compliance or perfusion. In patients with CFS, low intracranial compliance and high resting cerebral perfusion appear to be associated with an increased severity of symptoms of OI. This may signify alterations in the ability of the cerebral vasculature to cope with changes to systemic blood pressure due to orthostatic stress, but this may not be specific to CFS.

A systematic review of neurological impairments in myalgic encephalomyelitis/ chronic fatigue syndrome using neuroimaging techniques

“…Severity of OI symptoms was associated with lower intracranial compliance (change in volume per unit change in pressure), and higher intracranial perfusion. There were no significant differences in intracranial compliance or perfusion between ME/CFS patients and HCs [53].…”

“…Mean age across all studies was 40.9 years for ME/CFS patients and 39.07 years for HCs. Only 16 out of 55 papers reported a value for body mass index (BMI) or weight [11,12,[17][18][19]35,37,38,41,43,[53][54][55]. In all twin studies, levels of zygosity were assessed and ascertained at 99.9% [12,21,27].…”

“…In all twin studies, levels of zygosity were assessed and ascertained at 99.9% [12,21,27]. 47 of the 55 identified papers included participants that fulfilled the requirements of being diagnosed with the Fukuda criteria [12,14,[16][17][18][19][21][22][23][24][25][26][27][28]30,31,[34][35][36][37][38][39][40][41][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61]. Three of the papers used the more stringent CCC criteria to classify ME/CFS patients [15,29,42].…”

“…There were four different neuroimaging techniques used to assess neural changes in ME/ CFS compared with HCs. Out of the 55 studies: 16 studies utilised MRI [11,[13][14][15]20,[31][32][33][34][35][36]43,53,58,62,63], 17 used functional MRI (fMRI) [16,18,[21][22][23][24]26,34,[40][41][42][43]45,49,[49][50][51], five used PET scans [17,25,28,30,44] and 11 used EEG [12,27,29,38,39,[46][47][48]54,55]. The remaining studies used magnetic resonance spectrometry (MRS) [19,…”

Neuroimaging characteristics of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a systematic review

“…There was no group difference, although low intracranial compliance and high cerebral perfusion were associated with increased severity of symptoms of orthostatic intolerance in patients with ME/CFS [59].…”