Category: Neurology

Usefulness of an abnormal cardiovascular response during low-grade head-up tilt-test for discriminating adolescents with chronic fatigue from healthy controls

Abstract:

Hemodynamic dysfunction is documented in chronic fatigue syndrome (CFS). This study was conducted to investigate cardiovascular responses to orthostatic stress in adolescents with CFS, using a novel procedure for tilt-table testing.

A total of 27 adolescents with CFS and 33 healthy control subjects with equal age and gender distribution underwent 15 minutes of 20 degrees head-up tilt testing. Heart rate, systolic blood pressure (BP), mean BP, diastolic BP, stroke index, total peripheral resistance index, end-diastolic volume index, and acceleration index were continuously and noninvasively recorded.

At rest, patients with CFS had higher total peripheral resistance index values (p<0.01) and lower stroke index and end-diastolic volume index values (p<0.05) than controls. During 20 degrees head-up tilt testing, patients with CFS had greater increases in heart rate, diastolic BP (p<0.001), mean BP (p<0.01), and total peripheral resistance index (p<0.05) than controls and greater decreases in stroke index (p<0.05). Syncope or near syncope was not observed.

In conclusion, this study found that adolescents with CFS have significant abnormalities of cardiovascular regulation in response to mild orthostatic stress, differentiating them from healthy controls.

 

Source: Wyller VB, Due R, Saul JP, Amlie JP, Thaulow E. Usefulness of an abnormal cardiovascular response during low-grade head-up tilt-test for discriminating adolescents with chronic fatigue from healthy controls. Am J Cardiol. 2007 Apr 1;99(7):997-1001. Epub 2007 Feb 16. https://www.ncbi.nlm.nih.gov/pubmed/17398200

 

Fibromylagia, chronic fatigue, and adult attention deficit hyperactivity disorder in the adult: a case study

Abstract:

Adult attention deficit hyperactivity disorder (ADHD) may share common features with fibromyalgia syndrome (FMS) and chronic fatigue syndrome(CFS). In an outpatient psychiatric clinic, a number of adult patients who presented primarily with symptoms of ADHD, predominately inattentive type, also reported unexplained fatigue, widespread musculoskeletal pain or a pre-existing diagnosis of CFS or FMS.

As expected, ADHD pharmacotherapy usually attenuated the core ADHD symptoms of inattention, distractibility, hyperactivity, and impulsivity. Less expected was the observation that some patients also reported amelioration of pain and fatigue symptoms. The utility of ADHD medications in FMS and CFS states may be their innate arousal and enhanced filtering properties.

This model supposes that FMS and CFS are central processing problems rather than peripheral disorders of muscles and joints.

 

Source: Young JL, Redmond JC. Fibromylagia, chronic fatigue, and adult attention deficit hyperactivity disorder in the adult: a case study. Psychopharmacol Bull. 2007;40(1):118-26. https://www.ncbi.nlm.nih.gov/pubmed/17285103

 

Low-resolution electromagnetic brain tomography (LORETA) of monozygotic twins discordant for chronic fatigue syndrome

Abstract:

BACKGROUND: Previous work using quantified EEG has suggested that brain activity in individuals with chronic fatigue syndrome (CFS) and normal persons differs. Our objective was to investigate if specific frequency band-pass regions and spatial locations are associated with CFS using low-resolution electromagnetic brain tomography (LORETA).

METHODS: We conducted a co-twin control study of 17 pairs of monozygotic twins where 1 twin met criteria for CFS and the co-twin was healthy. Twins underwent an extensive battery of tests including a structured psychiatric interview and a quantified EEG. Eyes closed EEG frequency-domain analysis was computed and the entire brain volume was compared of the CFS and healthy twins using a multiple comparison procedure.

RESULTS: Compared with their healthy co-twins, twins with CFS differed in current source density. The CFS twins had higher delta in the left uncus and parahippocampal gyrus and higher theta in the cingulate gyrus and right superior frontal gyrus.

CONCLUSIONS: These findings suggest that neurophysiological activity in specific areas of the brain may differentiate individuals with CFS from those in good health. The study corroborates that slowing of the deeper structures of the limbic system is associated with affect. It also supports the neurobiological model that the right forebrain is associated with sympathetic activity and the left forebrain with the effective management of energy. These preliminary findings await replication.

 

Source: Sherlin L, Budzynski T, Kogan Budzynski H, Congedo M, Fischer ME, Buchwald D. Low-resolution electromagnetic brain tomography (LORETA) of monozygotic twins discordant for chronic fatigue syndrome. Neuroimage. 2007 Feb 15;34(4):1438-42. Epub 2006 Dec 13. https://www.ncbi.nlm.nih.gov/pubmed/17169580

Shortened QT interval: a distinctive feature of the dysautonomia of chronic fatigue syndrome

Abstract:

PURPOSE: Because autonomic nervous functioning is frequently abnormal in chronic fatigue syndrome (CFS), we examined whether the corrected QT interval (QTc) in CFS differs from QTc in other populations.

METHODS: The QTc was calculated at the end of 10 minutes of recumbence and the end of 10 minutes of head-up tilt. In a pilot study, groups of 15 subjects, CFS, and controls, matched for age and sex, were investigated. In a second phase of the study, the QTc was measured in larger groups of CFS (n = 30) and control patients (n = 96) not matched for demographic features.

RESULTS: In the pilot study, the average supine QTc in CFS was 0.371 +/- 0.02 seconds and QTc on tilt, 0.385 +/- 0.02 seconds, significantly shorter than in controls (P = .0002 and .0003, respectively). Results of phase II confirmed this data.

CONCLUSIONS: Relative short QTc intervals are features of the CFS-related dysautonomia. The significance of this finding is discussed.

 

Source: Naschitz J, Fields M, Isseroff H, Sharif D, Sabo E, Rosner I. Shortened QT interval: a distinctive feature of the dysautonomia of chronic fatigue syndrome. J Electrocardiol. 2006 Oct;39(4):389-94. Epub 2006 Feb 28. https://www.ncbi.nlm.nih.gov/pubmed/16895768

 

High-resolution magnetic resonance imaging sinc-interpolation-based subvoxel registration and semi-automated quantitative lateral ventricular morphology employing threshold computation and binary image creation in the study of fatty acid interventions in schizophrenia, depression, chronic fatigue syndrome and Huntington’s disease

Abstract:

Serial high-resolution structural magnetic resonance imaging scans of the brain can now be precisely aligned, with six degrees of freedom (three mutually orthogonal translational and three rotational degrees of freedom around three mutually orthogonal axes), using a rigid-body subvoxel registration technique. This is driven by the in-plane point spread function for images acquired in the Fourier domain with data obtained over a bounded region of k-space, namely the sinc interpolation function, where sinc z = (sin z)/z, with z being any complex number (including zero).

Computational subtraction of the three-dimensional Cartesian spatial representation matrices of serially acquired scan data allows for the determination of structural cerebral changes with great precision, since voxel signals from unchanged structures are almost completely cancelled. Thus changes readily show up against a background of noise. Furthermore, lateral ventricular changes can now be accurately quantified using a semi-automated method involving contour production, threshold computation, binary image creation and ventricular extraction.

These techniques have been applied to the investigation of the effects on cerebral structure of intervention with fatty acids, particularly the long-chain polyunsaturated n-3 fatty acid eicosapentaenoic acid (EPA), in disorders such as schizophrenia, treatment-resistant depression, chronic fatigue syndrome (myalgic encephalomyelitis or ME), and Huntington’s disease.

 

Source: Puri BK. High-resolution magnetic resonance imaging sinc-interpolation-based subvoxel registration and semi-automated quantitative lateral ventricular morphology employing threshold computation and binary image creation in the study of fatty acid interventions in schizophrenia, depression, chronic fatigue syndrome and Huntington’s disease. Int Rev Psychiatry. 2006 Apr;18(2):149-54. https://www.ncbi.nlm.nih.gov/pubmed/16777669

Proton and 31-phosphorus neurospectroscopy in the study of membrane phospholipids and fatty acid intervention in schizophrenia, depression, chronic fatigue syndrome (myalgic encephalomyelitis) and dyslexia

Abstract:

Neurospectroscopy allows biochemical processes in the brain to be studied non-invasively. At magnetic field strengths of 1.5 T or higher, cerebral proton neurospectroscopy allows the ascertainment of values of myo-inositol, choline-containing compounds, creatine, glutamate, glutamine, and N-acetyl aspartate. At similar field strengths, cerebral 31-phosphorus neurospectroscopy allows the ascertainment of values of phosphomonoesters, inorganic phosphate, phosphodiesters, phosphocreatine, and the gamma, alpha and beta nucleotide triphosphate (mainly adenosine triphosphate) resonances.

Since choline is a common polar head group at the Sn3 position of membrane phospholipid molecules, a raised level of free choline, as indexed by proton neurospectroscopy, can indicate relatively low anabolism of membrane phospholipid molecules. Furthermore, the choline peak includes phosphorylcholine and glycerophosphorylcholine and even ethanolamine. The phosphomonoesters peak measured using 31-phosphorus spectroscopy includes major contributions from phosphocholine, phosphoethanolamine and L-phosphoserine, which are important precursors of membrane phospholipids, while the phosphodiesters peak includes contributions from glycerophosphocholine and glycerophosphoethanolamine, which are important products of membrane phospholipid catabolism. Hence proton neurospectroscopy and 31-phosphorus neurospectroscopy can yield important information relating to the metabolism of cerebral membrane phospholipids.

The application of these techniques to the investigation of membrane phospholipid metabolism in schizophrenia, depression, chronic fatigue syndrome (myalgic encephalomyelitis or M.E.) and dyslexia is described.

 

Source: Puri BK. Proton and 31-phosphorus neurospectroscopy in the study of membrane phospholipids and fatty acid intervention in schizophrenia, depression, chronic fatigue syndrome (myalgic encephalomyelitis) and dyslexia. Int Rev Psychiatry. 2006 Apr;18(2):145-7. https://www.ncbi.nlm.nih.gov/pubmed/16777668

 

Reduced responsiveness is an essential feature of chronic fatigue syndrome: a fMRI study

Abstract:

BACKGROUND: Although the neural mechanism of chronic fatigue syndrome has been investigated by a number of researchers, it remains poorly understood.

METHODS: Using functional magnetic resonance imaging, we studied brain responsiveness in 6 male chronic fatigue syndrome patients and in 7 age-matched male healthy volunteers. Responsiveness of auditory cortices to transient, short-lived, noise reduction was measured while subjects performed a fatigue-inducing continual visual search task.

RESULTS: Responsiveness of the task-dependent brain regions was decreased after the fatigue-inducing task in the normal and chronic fatigue syndrome subjects and the decrement of the responsiveness was equivalent between the 2 groups. In contrast, during the fatigue-inducing period, although responsiveness of auditory cortices remained constant in the normal subjects, it was attenuated in the chronic fatigue syndrome patients. In addition, the rate of this attenuation was positively correlated with the subjective sensation of fatigue as measured using a fatigue visual analogue scale, immediately before the magnetic resonance imaging session.

CONCLUSION: Chronic fatigue syndrome may be characterised by attenuation of the responsiveness to stimuli not directly related to the fatigue-inducing task.

 

Source: Tanaka M, Sadato N, Okada T, Mizuno K, Sasabe T, Tanabe HC, Saito DN, Onoe H, Kuratsune H, Watanabe Y. BMC Neurol. 2006 Feb 22;6:9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1397862/ (Full article)

 

Patients with chronic fatigue syndrome have reduced absolute cortical blood flow

Abstract:

Prior studies on brain blood flow in chronic fatigue syndrome (CFS) did not find consistent results. This may be because they used single-photon emission computed tomography to measure brain blood flow, which could not measure absolute blood flow. Therefore, the aim of this study was to test the hypothesis that patients with CFS have reduced absolute cerebral blood flow. Xenon-computed tomography blood flow studies were done on 25 CFS patients and seven healthy controls. Analyses were done after stratifying the CFS patients based on the presence or absence of a current psychiatric disorder.

Flow was diminished in both groups as follows: patients with no current psychiatric disorders had reduced cortical blood flow in the distribution of both right and left middle cerebral arteries (P<0.05 for both) while those with current psychiatric disorders had reduced blood flow only in the left middle cerebral artery territory (P<0.05). These data indicate that patients with CFS have reduced absolute cortical blood flow in rather broad areas when compared with data from healthy controls and that those devoid of psychopathology had the most reductions in cortical flow. These data support, in part, our earlier findings that patients devoid of psychopathology are the group most at risk of having some of the symptoms of CFS due to brain dysfunction.

 

Source: Yoshiuchi K, Farkas J, Natelson BH. Patients with chronic fatigue syndrome have reduced absolute cortical blood flow. Clin Physiol Funct Imaging. 2006 Mar;26(2):83-6. https://www.ncbi.nlm.nih.gov/pubmed/16494597

 

Reliability of physiological, psychological, and cognitive variables in chronic fatigue syndrome

Abstract:

The purpose of this study was to assess the reliability of specific physiological, psychological, and cognitive variables in 31 chronic fatigue syndrome (CFS) subjects and 31 matched control subjects. All variables were assessed weekly over a 4-week period and reliability was determined using an intraclass correlation coefficient (ICC). Results ranged from moderately to highly reliable for all variables assessed, except for mental and physical fatigue, which were of questionable reliability in both groups (ICC = 0.61 and 0.65, respectively, for the CFS group; 0.62 and 0.52 for the control group).

A Pearson product-moment correlation analysis that compared exercise performance with all psychological variables assessed, demonstrated a significant relationship between exercise performance and depression (r = .41, P = .02) in week 3 only, suggesting minimal association between objective performance and psychological responses. These correlation results support a central, as opposed to a peripheral, basis to the sensation of fatigue in CFS.

 

Source: Wallman KE, Morton AR, Goodman C, Grove R. Reliability of physiological, psychological, and cognitive variables in chronic fatigue syndrome. Res Sports Med. 2005 Jul-Sep;13(3):231-41. http://www.ncbi.nlm.nih.gov/pubmed/16392538

 

Orthostatic instability in a population-based study of chronic fatigue syndrome

Abstract:

PURPOSE: Autonomic nervous system dysfunction has been suggested as involved in the pathophysiology of chronic fatigue syndrome. This population-based case control study addressed the potential association between orthostatic instability (one sign of dysautonomia) and chronic fatigue syndrome.

SUBJECTS AND METHODS: Fifty-eight subjects who fulfilled criteria of the 1994 chronic fatigue syndrome research case definition and 55 healthy controls participated in a 2-day inpatient evaluation. Subjects had been identified during a 4-year population-based chronic fatigue syndrome surveillance study in Wichita, Kan. The present study evaluated subjects’ current medical and psychiatric status, reviewed past medical/psychiatric history and medication use, used a stand-up test to screen for orthostatic instability, and conducted a head-up tilt table test to diagnose orthostatic instability.

RESULTS: No one manifested orthostatic instability in the stand-up test. The head-up tilt test elicited orthostatic instability in 30% of eligible chronic fatigue syndrome subjects (all with postural orthostatic tachycardia) and 48% of controls (50% with neurally mediated hypotension); intolerance was present in only nonfatigued (n=7) subjects. Neither fatigue nor illness severity were associated with outcome.

CONCLUSIONS: Orthostatic instability was similar in persons with chronic fatigue syndrome and nonfatigued controls subjects recruited from the general Wichita population. Delayed responses to head-up tilt tests were common and may reflect hydration status. These findings suggest reappraisal of primary dysautonomia as a factor in the pathogenesis of chronic fatigue syndrome.

Comment in: Orthostatic intolerance in chronic fatigue syndrome. [Am J Med. 2007]

 

Source: Jones JF, Nicholson A, Nisenbaum R, Papanicolaou DA, Solomon L, Boneva R, Heim C, Reeves WC. Orthostatic instability in a population-based study of chronic fatigue syndrome. Am J Med. 2005 Dec;118(12):1415. http://www.ncbi.nlm.nih.gov/pubmed/16378795