SPECT – American ME and CFS Society

Single-photon emission computerized tomography and neurocognitive function in patients with chronic fatigue syndrome

Erratum in: Psychosom Med. 2003 Mar-Apr;65(2):210.

Abstract:

OBJECTIVE: The purposes of this study were to compare functional imaging under control and experimental conditions among patients with chronic fatigue syndrome (CFS) and healthy persons and to examine perceived and objective performance on a test of attention and working memory previously found to be difficult for persons with CFS.

METHODS: Single-photon emission computerized tomography scans were completed on 15 subjects with CFS and 15 healthy persons twice: at rest and when performing the Paced Auditory Serial Addition Test (PASAT).

RESULTS: No group differences were found for performance on the PASAT despite CFS subjects’ perceptions of exerting more mental effort to perform the task than healthy subjects. Inspection of the aggregate scans by group and task suggested a pattern of diffuse regional cerebral blood flow among subjects with CFS in comparison with the more focal pattern of regional cerebral blood flow seen among healthy subjects. Between-group region-of-interest analysis revealed that although CFS subjects showed less perfusion in the anterior cingulate region, the change in CFS subjects’ activation of the left anterior cingulate region during the PASAT was greater than that observed for healthy subjects. The differences were not attributable to lesser effort by the subjects with CFS, confounding effects of mood perturbation, or to poorer performance on the experimental task.

CONCLUSIONS: Further research regarding CFS subjects’ diffuse cerebral perfusion and its relationship to inefficient neuropsychological performance is warranted.

Source: Schmaling KB, Lewis DH, Fiedelak JI, Mahurin R, Buchwald DS. Single-photon emission computerized tomography and neurocognitive function in patients with chronic fatigue syndrome. Psychosom Med. 2003 Jan-Feb;65(1):129-36. http://www.ncbi.nlm.nih.gov/pubmed/12554824

Chronic fatigue syndrome in childhood

Abstract:

Chronic fatigue occurring in previously healthy children and adolescents is one of the most vexing problems encountered by pediatric practitioners.

We report three cases, 11, 12 and 13-year-old children, with chronic fatigue syndrome (CFS). They initially developed a low grade fever and generalized fatigue, followed by sleep disturbance and psychosomatic symptoms, and their performance ability deteriorated. They were diagnosed as having CFS on the basis of criteria.

To investigate the brain function in CFS patients, we examined the regional cerebral blood flow by single-photon emission-computed tomography (SPECT) with 111 MBq [123I]-iodoamphetamine (123I-IMP) or xenon-computed tomography (Xe-CT), and brain metabolic levels by MR spectroscopy (MRS).

Blood flow, expressed as the corticocerebellar ratio (CCR), in the left temporal and occipital lobes was markedly lower in cases 2 and 3 than that in healthy subjects reported by another investigator. In case 1, however, blood flow in the left basal ganglia and thalamus was markedly higher than in healthy subjects. The MR spectroscopy (MRS) study revealed remarkable elevation of the choline/creatine ratio in the patients with CFS. None of our patients exhibited evidence of focal structural abnormalities on MRI.

These findings suggest that the various clinical symptoms in CFS patients may be closely related to an abnormal brain function.

Source: Tomoda A, Miike T, Yamada E, Honda H, Moroi T, Ogawa M, Ohtani Y, Morishita S. Chronic fatigue syndrome in childhood. Brain Dev. 2000 Jan;22(1):60-4. http://www.ncbi.nlm.nih.gov/pubmed/10761837

Comparison of SPET brain perfusion and 18F-FDG brain metabolism in patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome is a clinically defined condition of uncertain aetiology.

We compared 99Tcm-HMPAO single photon emission tomography (SPET) brain perfusion with dual-head 18F-FDG brain metabolism in patients with chronic fatigue syndrome. Eighteen patients (14 females, 4 males), who fulfilled the diagnostic criteria of the Centers for Disease Control for chronic fatigue syndrome, were investigated.

Thirteen patients had abnormal SPET brain perfusion scans and five had normal scans. Fifteen patients had normal glucose brain metabolism scans and three had abnormal scans. We conclude that, in chronic fatigue syndrome patients, there is discordance between SPET brain perfusion and 18F-FDG brain uptake. It is possible to have brain perfusion abnormalities without corresponding changes in glucose uptake.

Source: Abu-Judeh HH, Levine S, Kumar M, el-Zeftawy H, Naddaf S, Lou JQ, Abdel-Dayem HM. Comparison of SPET brain perfusion and 18F-FDG brain metabolism in patients with chronic fatigue syndrome. Nucl Med Commun. 1998 Nov;19(11):1065-71. http://www.ncbi.nlm.nih.gov/pubmed/9861623

Neuroimaging in chronic fatigue syndrome

Abstract:

The diagnosis of chronic fatigue syndrome (CFS) is made difficult by the absence of specific biomedical markers, and depends primarily on determining whether subjective information provided by the patient meets the clinical case definition of this syndrome. Reported cognitive difficulties and/or complaints of headache may instigate referral for brain imaging.

This article will discuss the value of neuroimaging in evaluating CFS, specifically reviewing studies that (1) used static magnetic resonance imaging (MRI) to assess structural abnormalities; and (2) assessed regional cerebral blood flow (rCBF) via detection of Tc-99m hexamethylpropyl-eneamine oxime distribution by single-photon emission computed tomography (SPECT). Future research design considerations are explored including (1) the utilization of positron emission tomography (PET) and other emerging neuroimaging technologies; and (2) methodological concerns, i.e., the influence of psychopathology (such as depression) and neurologic disease (such as multiple sclerosis) as possible confounding factors.

Source: Lange G, Wang S, DeLuca J, Natelson BH. Neuroimaging in chronic fatigue syndrome. Am J Med. 1998 Sep 28;105(3A):50S-53S. http://www.ncbi.nlm.nih.gov/pubmed/9790482

Chronic fatigue syndrome–aetiological aspects

Abstract:

The chronic fatigue syndrome (CFS) has been intensively studied over the last 40 years, but no conclusions have yet been agreed as to its cause. Most cases nowadays are sporadic. In the established chronic condition there are no consistently abnormal physical signs or abnormalities on laboratory investigation.

Many physicians remain convinced that the symptoms are psychological rather than physical in origin. This view is reinforced by the emotional way in which many patients present themselves. The overlap of symptoms between CFS and depression remains a source of confusion and difficulty. But even if all CFS patients were rediagnosed as depressives, this would not negate the possibility of an underlying organic cause for the condition, in view of the growing evidence that depression itself has a physical cause and responds best to physical treatments.

There is some evidence both for active viral infection and for an immunological disorder in the CFS. Many observations suggest that the syndrome could derive from residual damage to the reticular activating system (RAS) of the upper brain stem and/or to its cortical projections. Such damage could be produced by a previous viral infection, leaving functional defects unaccompanied by any gross histological changes.

In animal experiments activation of the RAS can change sleep state and activate or stimulate cortical functions. RAS lesions can produce somnolence and apathy. Studies by modern imaging techniques have not been entirely consistent, but many magnetic resonance imaging (MRI) studies already suggest that small discrete patchy brain stem and subcortical lesions can often be seen in CFS.

Regional blood flow studies by single photon-emission computerized tomography (SPECT) have been more consistent. They have revealed blood flow reductions in many regions, especially in the hind brain. Similar lesions have been reported after poliomyelitis and in multiple sclerosis–in both of which conditions chronic fatigue is characteristically present. In the well-known post-polio fatigue syndrome, lesions predominate in the RAS of the brain stem. If similar underlying lesions in the RAS can eventually be identified in CFS, the therapeutic target for CFS would be better defined than it is at present. A number of logical approaches to treatment can already be envisaged.

Comment in:

Chronic fatigue syndrome. [Eur J Clin Invest. 1997]

Source: Dickinson CJ. Chronic fatigue syndrome–aetiological aspects. Eur J Clin Invest. 1997 Apr;27(4):257-67. http://www.ncbi.nlm.nih.gov/pubmed/9134372

Comparison of 99m Tc HMPAO SPECT scan between chronic fatigue syndrome, major depression and healthy controls: an exploratory study of clinical correlates of regional cerebral blood flow

Abstract:

An explorative analysis of the relationship between symptomatology and cerebral blood flow in the chronic fatigue syndrome (CFS) as assessed with 99mTc HMPAO SPECT scan reveals statistically significant positive correlations between frontal blood flow on the one hand and objectively and subjectively assessed cognitive impairment, self-rating of physical activity limitations and total score on Hamilton Depression Rating Scale on the other. A pathophysiological role of frontal blood flow in the cognitive impairment and physical activity limitations in CFS is hypothesized.

A comparison of cerebral blood flow between CFS, major depression (MD) and healthy controls (HC) has been performed. A lower superofrontal perfusion index is demonstrated in MD as compared with both CFS and HC. There is neither a global nor a marked regional hypoperfusion in CFS compared with HC. Asymmetry (R > L) of tracer uptake at parietotemporal level is demonstrated in CFS as compared with MD.

Source: Fischler B, D’Haenen H, Cluydts R, Michiels V, Demets K, Bossuyt A, Kaufman L, De Meirleir K. Comparison of 99m Tc HMPAO SPECT scan between chronic fatigue syndrome, major depression and healthy controls: an exploratory study of clinical correlates of regional cerebral blood flow. Neuropsychobiology. 1996;34(4):175-83. http://www.ncbi.nlm.nih.gov/pubmed/9121617

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

Chronic fatigue syndrome–a review of the literature

Abstract:

Chronic fatigue syndrome is a clinical condition characterized by abnormal fatigue, subfebrile body temperature, sore throat, lymphadenopathy, arthralgia, myalgia and neuropsychiatric symptoms. Typically, the syndrome develops after a flu-like illness and is markedly exacerbated by exercise. The etiology is unknown and there is no single diagnostic test. The patients may have cognitive dysfunction, immunological and endocrinological abnormalities and abnormal mitochondria. Magnetic resonance imaging scans may show increased uptake of signals in the brain, and single photon emission computerized tomography reveals regional hypoperfusion of the brain. The author discusses similarities and distinctions between the syndrome and depression.

Source: Hamre HJ. Chronic fatigue syndrome–a review of the literature. Tidsskr Nor Laegeforen. 1995 Oct 10;115(24):3042-5. [Article in Norwegian] http://www.ncbi.nlm.nih.gov/pubmed/7570537

Fibromyalgia, chronic fatigue syndrome, and myofascial pain syndrome

Abstract:

Two important studies in which nuclear magnetic resonance spectroscopy was used convincingly demonstrated that muscle is not the primary pathologic factor in fibromyalgia. There were further studies reporting that fibromyalgia-chronic fatigue syndrome may follow well treated Lyme disease or mimic Lyme disease. The longest therapeutic trial to date in fibromyalgia demonstrated an initial modest effect of tricyclic medications, but at 6 months that efficacy was no longer evident. Investigation in both fibromyalgia and chronic fatigue syndrome now focuses on the central nervous system. The use of new technology, eg, neurohormonal assays and imaging such as single-photon emission computed tomography scan, may be important in understanding these elusive conditions.

Source: Goldenberg DL. Fibromyalgia, chronic fatigue syndrome, and myofascial pain syndrome. Curr Opin Rheumatol. 1995 Mar;7(2):127-35. http://www.ncbi.nlm.nih.gov/pubmed/7766493

Chronic fatigue syndrome. Preliminary report misrepresented

EDITOR,-We wish to point out an inaccuracy in Tony Delamothe’s review of ME/PVFS and the Press. Delamothe dismissively describes the preliminary report-initially published from our centre as a letter outlining an interesting observation on cerebral hypoperfusion specifically to the brain stem region of patients with myalgic encephalomyelitis-as not worthy of carrying equal weight with every other publication as no further details have been forthcoming since and it was only a 250 word letter. Firstly, further details of the findings were published as abstracts of presentations (refereed) to scientific societies in two specialist journals of nuclear medicine at the same time, giving the report the status of more than merely a letter.

You can read the rest of this letter here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540198/pdf/bmj00440-0054b.pdf

Source: Tannock C, Costa DC, Brostoff J. Chronic fatigue syndrome. Preliminary report misrepresented. BMJ. 1994 May 14;308(6939):1298. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2540198/