Category: Neurology

Neuropsychology and psychology of MCS

Abstract:

Neurological symptoms are frequently reported by patients with multiple chemical sensitivities (MCS). Methods to compare the psychiatric, personality, and neuropsychological function of patients with MCS, chronic fatigue syndrome (CFS), and normal controls are described. Increased rates of Axis I psychiatric diagnoses are observed in the literature for MCS and CFS subjects relative to controls.

Findings on the MMPI-2 and the Toronto Alexithymia Scale reveal profiles consistent with the tendency to report somatic rather than emotional symptoms in response to stress. However, many of the reported somatic symptoms also coincide with those found in neurologic disorders. The overall neuropsychological profile for MCS subjects does not reflect cognitive impairment.

Relative to normal controls, the only difference in neuropsychological performance observed is reduced recognition of nontarget designs on a visual memory task. More fruitful areas for future psychological research will include measurement of the interaction between behavioral response styles and attentional processes in cognition, as well as observations under controlled challenge conditions.

 

Source: Fiedler N, Kipen H, Deluca J, Kelly-McNeil K, Natelson B. Neuropsychology and psychology of MCS. Toxicol Ind Health. 1994 Jul-Oct;10(4-5):545-54. http://www.ncbi.nlm.nih.gov/pubmed/7778113

 

Neuropsychiatric status of patients with chronic fatigue syndrome: an overview

Abstract:

Chronic fatigue syndrome (CFS) is an illness that results in debilitating fatigue as well as rheumatological, infectious, and neuropsychiatric symptoms. The present paper is a brief overview of the neuropsychological and psychiatric research on CFS. Studies from our laboratory contrasting CFS with patients with multiple sclerosis, depression, and healthy controls are detailed. Our hypothesis of neuropsychological impairments in CFS is discussed.

 

Source: Deluca J, Johnson SK, Natelson BH. Neuropsychiatric status of patients with chronic fatigue syndrome: an overview. Toxicol Ind Health. 1994 Jul-Oct;10(4-5):513-22. http://www.ncbi.nlm.nih.gov/pubmed/7778111

 

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/

 

SPECT imaging of the brain: comparison of findings in patients with chronic fatigue syndrome, AIDS dementia complex, and major unipolar depression

Abstract:

OBJECTIVE: Chronic fatigue syndrome is an illness of unknown origin that begins abruptly with a flulike state and has symptoms suggesting both a chronic viral encephalitis and an affective disorder. We compared single-photon emission computed tomography (SPECT) scans of patients with chronic fatigue syndrome with those of patients with AIDS dementia complex and unipolar depression.

SUBJECTS AND METHODS: We used 99mTc-hexamethylpropyleneamine oxime to examine 45 patients with chronic fatigue syndrome, 27 patients with AIDS dementia complex, and 14 patients with major unipolar depression. Scans of 38 healthy persons were used as controls. Comparison of regional defects between groups, as well as midcerebral uptake indexes (an objective measure of global radionuclide uptake), was performed by using analysis of variance with the Student-Newman-Keuls option. Correlation between the number of regional defects and the midcerebral uptake index was determined by using the Spearman rank-correlation test.

RESULTS: Patients with AIDS dementia complex had the largest number of defects (9.15 per patient) and healthy patients had the fewest defects (1.66 per patient). Patients with chronic fatigue syndrome and depression had similar numbers of defects per patient (6.53 and 6.43, respectively). In all groups, defects were located predominantly in the frontal and temporal lobes. The midcerebral uptake index was found to be significantly lower (p < .002) in the patients with chronic fatigue syndrome (.667) and patients with AIDS dementia complex (.650) than in patients with major depression (.731) or healthy control subjects (.716). Also, a significant negative correlation was found between the number of defects and midcerebral uptake index in patients with chronic fatigue syndrome and AIDS dementia complex, but not in depressed patients or control subjects.

CONCLUSION: These findings are consistent with the hypothesis that chronic fatigue syndrome may be due to a chronic viral encephalitis; clinical similarities between chronic fatigue syndrome and depression may be due to a similar distribution and number of defects in the two disorders.

 

Source: Schwartz RB, Komaroff AL, Garada BM, Gleit M, Doolittle TH, Bates DW, Vasile RG, Holman BL. SPECT imaging of the brain: comparison of findings in patients with chronic fatigue syndrome, AIDS dementia complex, and major unipolar depression. AJR Am J Roentgenol. 1994 Apr;162(4):943-51. http://www.ncbi.nlm.nih.gov/pubmed/8141022

 

Detection of intracranial abnormalities in patients with chronic fatigue syndrome: comparison of MR imaging and SPECT

Abstract:

OBJECTIVE: Chronic fatigue syndrome is a recently characterized condition of unknown origin that is manifested by fatigue, flulike complaints, and neurologic signs and symptoms, including persistent headache, impaired cognitive abilities, mood disorders, and sensorimotor disturbances. This syndrome can be difficult to diagnose clinically or by standard neuroradiologic tests. We performed MR imaging and single-photon emission computed tomography (SPECT) in patients with chronic fatigue syndrome to compare the usefulness of functional and anatomic imaging in the detection of intracranial abnormalities.

SUBJECTS AND METHODS: Sixteen patients who fulfilled the Centers for Disease Control, British, and/or Australian criteria for chronic fatigue syndrome had MR and SPECT examinations within a 10-week period. Axial MR and SPECT scans were analyzed as to the number and location of focal abnormalities by using analysis of variance with the Student-Newman-Keuls option. MR imaging findings in patients with chronic fatigue syndrome were compared with those in 15 age-matched control subjects, and SPECT findings in the patients with chronic fatigue syndrome were compared with those in 14 age-matched control subjects by using Fisher’s exact test. The findings on MR and SPECT scans in the same patients were compared by using the Wilcoxon matched-pairs signed-ranks test.

RESULTS: MR abnormalities consisted of foci of T2-bright signal in the periventricular and subcortical white matter and in the centrum semiovale; there were 2.06 foci per patient, vs 0.80 foci per control subject. MR abnormalities were present in eight (50%) of 16 patients, compared with three (20%) of 15 age-matched control subjects. Neither of these differences reached significance, although the power of the study to detect differences between groups was small. Patients with chronic fatigue syndrome had significantly more defects throughout the cerebral cortex on SPECT scans than did normal subjects (7.31 vs 0.43 defects per subject, p < .001). SPECT abnormalities were present in 13 (81%) of 16 patients, vs three (21%) of 14 control subjects (p < .01). SPECT scans showed significantly more abnormalities than did MR scans in patients with chronic fatigue syndrome (p < .025). In the few patients who had repeat SPECT and MR studies, the number of SPECT abnormalities appeared to correlate with clinical status, whereas MR changes were irreversible.

CONCLUSION: SPECT abnormalities occur more frequently and in greater numbers than MR abnormalities do in patients with chronic fatigue syndrome. SPECT may prove to be useful in following the clinical progress of patients with this syndrome.

 

Source: Schwartz RB, Garada BM, Komaroff AL, Tice HM, Gleit M, Jolesz FA, Holman BL. Detection of intracranial abnormalities in patients with chronic fatigue syndrome: comparison of MR imaging and SPECT. AJR Am J Roentgenol. 1994 Apr;162(4):935-41. http://www.ncbi.nlm.nih.gov/pubmed/8141020

 

Single fibre EMG studies in chronic fatigue syndrome: a reappraisal

Abstract:

Single fibre EMG studies were carried out on the right extensor digitorum communis muscle in 30 subjects with chronic fatigue syndrome and in 30 age and sex matched controls. Abnormal jitter was seen in five patients with chronic fatigue syndrome. Slight but significant differences between the mean consecutive differences in the remainder of the chronic fatigue subjects and the control subjects were recorded. Overall the differences were so minor that it seems unlikely that a disturbance of neuromuscular function as reflected by jitter measurement has a pathogenetic role. It is suggested that the increased jitter seen may be explained by the effects of the variability of motor unit firing rates on the myogenic component of the jitter.

Comment in: Single fibre EMG studies in chronic fatigue syndrome: a reappraisal. [J Neurol Neurosurg Psychiatry. 1994]

 

Source: Roberts L, Byrne E. Single fibre EMG studies in chronic fatigue syndrome: a reappraisal. J Neurol Neurosurg Psychiatry. 1994 Mar;57(3):375-6. http://www.ncbi.nlm.nih.gov/pubmed/8158191

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1072834/pdf/jnnpsyc00033-0119.pdf

 

Effects of mild exercise on cytokines and cerebral blood flow in chronic fatigue syndrome patients

 

Abstract:

Chronic fatigue syndrome (CFS) is an idiopathic disorder characterized by fatigue that is markedly exacerbated by physical exertion. In the present study, we tested the hypothesis that mild exercise (walking 1 mph [1 mile = 1.609 km] for 30 min) would provoke serum cytokine and cerebral blood flow abnormalities of potential pathogenic importance in CFS.

Interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha were nondetectable in sera of CFS patients (n = 10) and healthy control subjects (n = 10) pre- and postexercise. At rest, serum transforming growth factor beta (TGF-beta) levels were elevated in the CFS group compared with the control group (287 +/- 18 versus 115 +/- 5 pg/ml, respectively; P < 0.01). Serum TGF-beta and cerebral blood flow abnormalities, detected by single-photon emission-computed tomographic scanning, were accentuated postexercise in the CFS group.

Although these findings were not significantly different from those in the control group, the effect of exercise on serum TGF-beta and cerebral blood flow appeared magnified in the CFS patients. Results of this study encourage future research on the interaction of physical exertion, serum cytokines, and cerebral blood flow in CFS that will adopt a more rigorous exercise program than the one used in this study.

 

Source: Peterson PK, Sirr SA, Grammith FC, Schenck CH, Pheley AM, Hu S, Chao CC. Effects of mild exercise on cytokines and cerebral blood flow in chronic fatigue syndrome patients. Clin Diagn Lab Immunol. 1994 Mar;1(2):222-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC368231/

You can read the full article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC368231/pdf/cdli00002-0112.pdf

 

A comparative review of systemic and neurological symptomatology in 12 outbreaks collectively described as chronic fatigue syndrome, epidemic neuromyasthenia, and myalgic encephalomyelitis

Abstract:

Outbreaks of illnesses of unknown etiology typified by a chronic relapsing course of constitutional symptoms and nervous system involvement have collectively been referred to as chronic fatigue syndrome, epidemic neuromyasthenia, and myalgic encephalomyelitis. To examine heterogeneity of clinical presentation, a comparative review was undertaken for 12 well-documented outbreaks reported since 1934.

A systemic syndrome characterized by excessive fatigue, myalgias, headache, low-grade fever, and other constitutional symptoms was common to cases in all outbreaks. However, marked heterogeneity in the range of neurological features was apparent.

On the basis of predominant neurological manifestations, outbreaks could be grouped into four levels of increasing neurological involvement: affective neuropsychological changes (level I); prominent cutaneous sensory symptoms with both affective and cognitive neuropsychological changes (level II); marked objective paresis with cutaneous sensory as well as affective and cognitive neuropsychological changes (level III); and cutaneous sensory, affective and cognitive neuropsychological, posterior column, cranial nerve, and mixed upper and lower motor neuron changes (level IV). Groups with the most prominent objective neurological findings (levels III and IV) comprised exclusively outbreaks reported between the 1930s and 1950s. All but one outbreak in groups with less prominent neurological findings (levels I and II) were reported between the 1960s and 1980s; a range of neurological features was observed for these groups.

Because a complete neurological examination is not emphasized as part of the diagnostic workup in current outbreaks, it is possible that less obvious neurological findings may be overlooked. Careful evaluation of neurological features in epidemic and endemic cases of what is now called chronic fatigue syndrome may be one approach to distinguishing subtypes of what has been described in the past as a nosological entity.

 

Source: Briggs NC, Levine PH. A comparative review of systemic and neurological symptomatology in 12 outbreaks collectively described as chronic fatigue syndrome, epidemic neuromyasthenia, and myalgic encephalomyelitis. Clin Infect Dis. 1994 Jan;18 Suppl 1:S32-42. http://www.ncbi.nlm.nih.gov/pubmed/8148451

 

A controlled study of brain magnetic resonance imaging in patients with the chronic fatigue syndrome

Abstract:

Two neuroradiologists compared the brain MR scans of 52 patients with the CDC criteria for the chronic fatigue syndrome (CFS) with those of 52 age and sex matched controls who had undergone imaging because of histories of head trauma or headache.

CFS patients had significantly more abnormal scans than controls–27% vs 2%. Abnormalities seen were foci of increased white matter T2 signal in 9 CFS patients and one control and ventricular or sulcal enlargement in 5 CFS patients. Follow up of patients with subcortical signal hyperintensities revealed 3 who had symptoms suggestive of other known medical causes of what appeared to be CFS.

The data indicate that some CFS patients have some organic problem manifesting itself on neuroimaging. But, finding MR abnormalities should warn the physician that the patient’s symptoms may be secondary to some other medical illness and not simply primary CFS.

 

Source: Natelson BH, Cohen JM, Brassloff I, Lee HJ. A controlled study of brain magnetic resonance imaging in patients with the chronic fatigue syndrome. J Neurol Sci. 1993 Dec 15;120(2):213-7. http://www.ncbi.nlm.nih.gov/pubmed/8138812

 

Behavioural problems associated with the chronic fatigue syndrome

Abstract:

Disturbances of memory, concentration and motor function are often reported by patients with the chronic fatigue syndrome (CFS). The present study objectively evaluated these behavioural problems using a computerized test battery measuring memory, attention and motor skills.

Fifty-seven CFS patients were compared with 19 matched controls and all subjects completed the performance test battery and filled in questionnaires measuring psychopathology and mood. The patients reported significantly higher levels of depression, anxiety, physical symptoms and cognitive failures than the controls. Similarly, they reported more negative affect at the time of testing.

The patients were slower on psychomotor tasks, showed increased visual sensitivity and impaired attention. Digit span and free recall were not impaired but retrieval from semantic memory and logical reasoning were slower. None of the performance differences between patients and controls could be attributed to differences in psychopathology. These results agree with recent findings from other laboratories, and it is now time to consider the nature of the neurological dysfunction underlying these effects.

 

Source: Smith AP, Behan PO, Bell W, Millar K, Bakheit M. Behavioural problems associated with the chronic fatigue syndrome. Br J Psychol. 1993 Aug;84 ( Pt 3):411-23. http://www.ncbi.nlm.nih.gov/pubmed/8401992