Tag: brainstem

Mapping of pathological change in chronic fatigue syndrome using the ratio of T1- and T2-weighted MRI scans

Abstract:

Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (ME/CFS) subjects suffer from a variety of cognitive complaints indicating that the central nervous system plays a role in its pathophysiology. Recently, the ratio T1w/T2w has been used to study changes in tissue myelin and/or iron levels in neurodegenerative diseases such as multiple sclerosis and schizophrenia. In this study, we applied the T1w/T2w method to detect changes in tissue microstructure in ME/CFS patients relative to healthy controls.

We mapped the T1w/T2w signal intensity values in the whole brain for forty-five ME/CFS patients who met Fukuda criteria and twenty-seven healthy controls and applied both region- and voxel-based quantification. We also performed interaction-with-group regressions with clinical measures to test for T1w/T2w relationships that are abnormal in ME/CFS at the population level.

Region-based analysis showed significantly elevated T1w/T2w values (increased myelin and/or iron) in ME/CFS in both white matter (WM) and subcortical grey matter. The voxel-based group comparison with sub-millimetre resolution voxels detected very significant clusters with increased T1w/T2w in ME/CFS, mostly in subcortical grey matter, but also in brainstem and projection WM tracts. No areas with decreased T1w/T2w were found in either analysis. ME/CFS T1w/T2w regressions with heart-rate variability, cognitive performance, respiration rate and physical well-being were abnormal in both gray and white matter foci. Our study demonstrates that the T1w/T2w approach is very sensitive and shows increases in myelin and/or iron in WM and basal ganglia in ME/CFS.

Source: Thapaliya K, Marshall-Gradisnik S, Staines D, Barnden L. Mapping of pathological change in chronic fatigue syndrome using the ratio of T1- and T2-weighted MRI scans [published online ahead of print, 2020 Jul 31]. Neuroimage Clin. 2020;28:102366. doi:10.1016/j.nicl.2020.102366 https://pubmed.ncbi.nlm.nih.gov/32777701/

Intra brainstem connectivity is impaired in chronic fatigue syndrome

Abstract:

In myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), abnormal MRI correlations with symptom severity and autonomic measures have suggested impaired nerve signal conduction within the brainstem. Here we analyse fMRI correlations to directly test connectivity within and from the brainstem. Resting and task functional MRI (fMRI) were acquired for 45 ME/CFS (Fukuda criteria) and 27 healthy controls (HC).

We selected limited brainstem reticular activation system (RAS) regions-of-interest (ROIs) based on previous structural MRI findings in a different ME/CFS cohort (bilateral rostral medulla and midbrain cuneiform nucleus), the dorsal Raphe nucleus, and two subcortical ROIs (hippocampus subiculum and thalamus intralaminar nucleus) reported to have rich brainstem connections.

When HC and ME/CFS were analysed separately, significant correlations were detected for both groups during both rest and task, with stronger correlations during task than rest. In ME/CFS, connections were absent between medulla and midbrain nuclei, although hippocampal connections with these nuclei were enhanced.

When corresponding correlations from HC and ME/CFS were compared, ME/CFS connectivity deficits were detected within the brainstem between the medulla and cuneiform nucleus and between the brainstem and hippocampus and intralaminar thalamus, but only during task.

In CFS/ME, weaker connectivity between some RAS nuclei was associated with increased symptom severity. RAS neuron oscillatory signals facilitate coherence in thalamo-cortical oscillations. Brainstem RAS connectivity deficits can explain autonomic changes and diminish cortical oscillatory coherence which can impair attention, memory, cognitive function, sleep quality and muscle tone, all symptoms of ME/CFS.

Copyright © 2019 The Authors. Published by Elsevier Inc. All rights reserved.

Source: Barnden LR, Shan ZY, Staines DR, Marshall-Gradisnik S, Finegan K, Ireland T, Bhuta S. Intra brainstem connectivity is impaired in chronic fatigue syndrome. Neuroimage Clin. 2019 Oct 19;24:102045. doi: 10.1016/j.nicl.2019.102045. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31671321

Hyperintense sensorimotor T1 spin echo MRI is associated with brainstem abnormality in chronic fatigue syndrome

Abstract:

We recruited 43 Chronic Fatigue Syndrome (CFS) subjects who met Fukuda criteria and 27 healthy controls and performed 3T MRI T1 and T2 weighted spin-echo (T1wSE and T2wSE) scans. T1wSE signal follows T1 relaxation rate (1/T1 relaxation time) and responds to myelin and iron (ferritin) concentrations. We performed MRI signal level group comparisons with SPM12. Spatial normalization after segmentation was performed using T2wSE scans and applied to the coregistered T1wSE scans.

After global signal-level normalization of individual scans, the T1wSE group comparison detected decreased signal-levels in CFS in a brainstem region (cluster-based inference controlled for family wise error rate, PFWE= 0.002), and increased signal-levels in large bilateral clusters in sensorimotor cortex white matter (cluster PFWE < 0.0001). Moreover, the brainstem T1wSE values were negatively correlated with the sensorimotor values for both CFS (R2 = 0.31, P = 0.00007) and healthy controls (R2= 0.34, P = 0.0009), and the regressions were co-linear.

This relationship, previously unreported in either healthy controls or CFS, in view of known thalamic projection-fibre plasticity, suggests brainstem conduction deficits in CFS may stimulate the upregulation of myelin in the sensorimotor cortex to maintain brainstem – sensorimotor connectivity. VBM did not find group differences in regional grey matter or white matter volumes. We argued that increased T1wSE observed in sensorimotor WM in CFS indicates increased myelination which is a regulatory response to deficits in the brainstem although the causality cannot be tested in this study. Altered brainstem myelin may have broad consequences for cerebral function and should be a focus of future research.

Source: Barnden LR, Shan ZY, Staines DR, Marshall-Gradisnik S, Finegan K, Ireland T, Bhuta S. Hyperintense sensorimotor T1 spin echo MRI is associated with brainstem abnormality in chronic fatigue syndrome. Neuroimage Clin. 2018;20:102-109. doi: 10.1016/j.nicl.2018.07.011. Epub 2018 Jul 11. https://www.ncbi.nlm.nih.gov/pubmed/30497131

Autonomic correlations with MRI are abnormal in the brainstem vasomotor centre in Chronic Fatigue Syndrome

Abstract:

Autonomic changes are often associated with the chronic fatigue syndrome (CFS), but their pathogenetic role is unclear and brain imaging investigations are lacking. The vasomotor centre and, through it, nuclei in the midbrain and hypothalamus play a key role in autonomic nervous system regulation of steady state blood pressure (BP) and heart rate (HR).

In this exploratory cross-sectional study, BP and HR, as indicators of autonomic function, were correlated with volumetric and T1- and T2-weighted spin-echo (T1w and T2w) brain MRI in 25 CFS subjects and 25 normal controls (NC). Steady state BP (systolic, diastolic and pulse pressure) and HR in two postures were extracted from 24 h blood pressure monitoring. We performed (1) MRI versus autonomic score interaction-with-group regressions to detect locations where regression slopes differed in the CFS and NC groups (collectively indicating abnormality in CFS), and (2) MRI regressions in the CFS and NC groups alone to detect additional locations with abnormal correlations in CFS.

Significant CFS regressions were repeated controlling for anxiety and depression (A&D). Abnormal regressions were detected in nuclei of the brainstem vasomotor centre, midbrain reticular formation and hypothalamus, but also in limbic nuclei involved in stress responses and in prefrontal white matter. Group comparisons of CFS and NC did not find MRI differences in these locations.

We propose therefore that these regulatory nuclei are functioning correctly, but that two-way communication between them is impaired in CFS and this affects signalling to/from peripheral effectors/sensors, culminating in inverted or magnified correlations. This single explanation for the diverse abnormal correlations detected here consolidates the conclusion for a brainstem/midbrain nerve conduction deficit inferred earlier (Barnden et al., 2015). Strong correlations were also detected in isolated NC regressions.

 

Source: Barnden LR, Kwiatek R, Crouch B, Burnet R, Del Fante P. Autonomic correlations with MRI are abnormal in the brainstem vasomotor centre in Chronic Fatigue Syndrome. Neuroimage Clin. 2016 Mar 31;11:530-7. doi: 10.1016/j.nicl.2016.03.017. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4833047/ (Full article)

 

Brainstem conundrum: the Chiari I malformation

Abstract:

PURPOSE: To describe the Chairi I Malformation in relation to the anatomy of the brain and spinal cord, the common manifestations of the condition, diagnostic considerations, and management for the primary care provider.

DATA SOURCES: Extensive review of the world-wide scientific literature on the condition, supplemented with actual case studies.

CONCLUSIONS: The adult Chairi I Malformation is an insidious congenital brainstem anomaly that consists of caudal displacement of the cerebellar tonsils, brainstem and fourth ventricle into the upper cervical space, resulting in overcrowding of the posterior fossa.

IMPLICATIONS FOR PRACTICE: Due to the vague, and often ambiguous presenting symptoms of Chiari I Malformation, many patients are misdiagnosed with conditions such as multiple sclerosis, fibromyalgia, chronic fatigue syndrome, or psychiatric disorders. Patients frequently experience symptoms months to years prior to accurate diagnosis and often incur irreversible neurologic deficits.

 

Source: Mueller D. Brainstem conundrum: the Chiari I malformation. J Am Acad Nurse Pract. 2001 Apr;13(4):154-9. http://www.ncbi.nlm.nih.gov/pubmed/11930527

 

Brain positron emission tomography (PET) in chronic fatigue syndrome: preliminary data

Abstract:

Chronic fatigue syndrome (CFS) has been widely studied by neuroimaging techniques in recent years with conflicting results. In particular, using single-photon emission computed tomography (SPECT) and perfusion tracers, hypoperfusion has been found in several brain regions, although the findings vary across research centers. The objective of this study was to investigate brain metabolism of patients affected by CFS, using [18F]fluorine-deoxyglucose (18FDG) positron emission tomography (PET).

We performed 18FDG PET in 18 patients who fulfilled the criteria of the working case definition of CFS. Twelve of the 18 patients were females; the mean age was 34 +/- 15 years (range, 15-68) and the median time from CFS diagnosis was 16 months (range, 9-138). Psychiatric diseases and anxiety/neurosis were excluded in all CFS patients.

CFS patients were compared with a group of 6 patients affected by depression (according to DSM IV-R) and 6 age-matched healthy controls. The CFS patients were not taking any medication at the time of PET, and depressed patients were drug-free for at least 1 week before the PET examination. The PET images examined 22 cortical and subcortical areas.

CFS patients showed a significant hypometabolism in right mediofrontal cortex (P = 0.010) and brainstem (P = 0.013) in comparison with the healthy controls. Moreover, comparing patients affected by CFS and depression, the latter group showed a significant and severe hypometabolism of the medial and upper frontal regions bilaterally (P = 0.037-0.001), whereas the metabolism of brain stem was normal.

Brain 18FDG PET showed specific metabolism abnormalities in patients with CFS in comparison with both healthy controls and depressed patients. The most relevant result of our study is the brain stem hypometabolism which, as reported in a perfusion SPECT study, seems to be a marker for the in vivo diagnosis of CFS.

 

Source: Tirelli U, Chierichetti F, Tavio M, Simonelli C, Bianchin G, Zanco P, Ferlin G. Brain positron emission tomography (PET) in chronic fatigue syndrome: preliminary data. Am J Med. 1998 Sep 28;105(3A):54S-58S. http://www.ncbi.nlm.nih.gov/pubmed/9790483

 

“Prolonged” decay test and auditory brainstem responses in the clinical diagnosis of the chronic fatigue syndrome

Abstract:

The chronic fatigue syndrome (CFS) was formally defined to describe disabling fatigue of unknown etiology with immunologic disfunctions. In most cases occur abnormalities of neurophysiological tests.

In this paper the Authors use the low (11 pps) and high (51-71 pps) frequency ABR for detecting the electrophysiological function of auditory brainstem responses and propose the “Prolonged Decay Test”, a modified impedenzometric technique that explores any alterations of the stapedial contraction, as a new diagnostic test for CFS.

Twenty-one patients with suspected CFS, with an age between 17 and 50 years, were examined and the instrumental data were correlated with the clinical findings. The results of the ABR study showed in the examined subjects no many abnormalities in the 11 pps frequency test. The high frequency stimulation trials (with 51 and 71 pps) proved many alterations in 10 patients (absence of the first wave in 6 cases, in 5 many wave latency delay and in 1 patient absence of the first wave and many wave latency delay). The high frequency trials showed no abnormalities in the 11 remaining patients.

The clinical-audiological correlation showed a 61.9% of comparison with 33.3% of false negatives and 4.8% of false positives. The Prolonged Decay Test showed a 71.4% of clinical-audiological comparison with 23.8% of false negatives and 4.8% of false positives. The Prolonged Decay Test together with the ABR showed a 81.8% of clinical-audiological comparison with 18.2% of false negatives and 0% of false positives.

These preliminary data show that the stapedial reflex together with the ABR test could be useful for the diagnosis of CFS.

 

Source: Neri G, Bianchedi M, Croce A, Moretti A. “Prolonged” decay test and auditory brainstem responses in the clinical diagnosis of the chronic fatigue syndrome. Acta Otorhinolaryngol Ital. 1996 Aug;16(4):317-23. [Article in Italian] http://www.ncbi.nlm.nih.gov/pubmed/9082825

 

Auditory brain stem evoked potentials in the evaluation of chronic fatigue syndrome

Abstract:

The Chronic Fatigue Syndrome (CFS) was formally defined to describe disabling fatigue of multifactorial ethology with depression and immunologic dysfunctions linked to some currently recognized infectious agents. In most cases neurophysiological tests reveal abnormalities.

In this paper the Authors use low (11 pps) and high (51-71 pps) frequency ABR to evaluate the electrophysiological function of auditory brainstem responses. Eighteen patients with suspected CFS, between the ages of 17 and 63, were examined. Eleven subjects had clinically diagnosed “true” CFS (CDC criteria modified by Fukuda). The 11 pps frequency test did not reveal a high number of abnormalities in the patients in question.

However, the high frequency stimulation test (with 51 and 71 pps) which was statistically significant (P = 0.009) revealed numerous aberrations in 7 patients; absence of the first wave in 1 case, in 5 numerous wave gap delays and in 1 patient absence of the first wave and numerous wave gap delays. The high frequency test did not show many abnormalities for the 4 remaining patients. For the 7 “non CFS” subjects, the clinical-audiological comparison showed no statistical significance (P = 0.920).

The Authors hypothesize that the absence of the first wave in the CFS Subject may well indicate a cyto-neural junction disease in the organ of Corti. The combined analysis of clinical and audiological data showed that the described tests are more reliable when employed in dealing with patients with clinically assessed “true” CFS.

 

Source: Bianchedi M, Croce A, Moretti A, Neri G, Barberio A, Iezzi A, Pizzigallo E. Auditory brain stem evoked potentials in the evaluation of chronic fatigue syndrome. Acta Otorhinolaryngol Ital. 1995 Dec;15(6):403-10. [Article in Italian] http://www.ncbi.nlm.nih.gov/pubmed/8711992

 

Brainstem perfusion is impaired in chronic fatigue syndrome

Abstract:

We looked for brain perfusion abnormalities in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). An initial pilot study revealed widespread reduction of regional brain perfusion in 24 ME/CFS patients, compared with 24 normal volunteers. Hypoperfusion of the brainstem (0.72 +/- 0.05 vs. 0.80 +/- 0.04, p < 0.0001) was marked and constant. We then tested whether perfusion to the brainstem in ME/CFS patients differs from that in normals, patients with major depression, and others with epilepsy.

Data from a total of 146 subjects were included in the present study: 40 normal volunteers, 67 patients with ME/CFS (24 in the pilot study, 16 with no psychiatric disorders, 13 with ME/CFS and depression, 14 with ME/CFS and other psychiatric disorders), 10 epileptics, 20 young depressed patients and 9 elderly depressed individuals.

Brain perfusion ratios were calculated using 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) and single-photon emission tomography (SPET) with a dedicated three-detector gamma camera computer/system (GE Neurocam).

Brain-stem hypoperfusion was confirmed in all ME/CFS patients. Furthermore, the 16 ME/CFS patients with no psychiatric disorders and the initial 24 patients in the pilot study showed significantly lower brainstem perfusion (0.71 +/- 0.03) than did depressed patients (0.77 +/- 0.03; ANOVA, p < 0.0001).

Patients with ME/CFS have a generalized reduction of brain perfusion, with a particular pattern of hypoperfusion of the brainstem.

Comment in: Brainstem hypoperfusion in CFS. [QJM. 1996]

 

Source: Costa DC, Tannock C, Brostoff J. Brainstem perfusion is impaired in chronic fatigue syndrome. QJM. 1995 Nov;88(11):767-73. http://www.ncbi.nlm.nih.gov/pubmed/8542261