Psychophysiological features of somatosensory disorders in victims of the Chernobyl accident

Author: Loganovsky K.N.

Reference: Fiziol Cheloveka. — 2003. — Vol. 29, № 1. — P. 122–130.

Keywords: Chernobyl, Afghanistan, PTSD, Somatosensory evoked potentials

Abstract: Participants of the Chernobyl clean-up (n = 145) teams exposed to radiation doses from 0.05 to 3.5 Gy who had for the first time complained of pathologic somatosensory sensations (ostealgic syndrome), 20 healthy subjects, and 50 veterans of the war in Afghanistan with posttraumatic stress disorder (PTSD) were examined by a neuropsychiatrist and presented with the MMPI test. Somatosensory evoked potentials (SSEPs) were recorded. Paresthesia and cenesthopathy were characteristic of the participants of the Chernobyl clean-up. Sensation disorders of the cerebral type, kinesthetic illusions, cenesthopathic hypochondriac disorders, and paroxysmal psychosensory states predominated in this group of subjects. They differed significantly from the veterans with PTSD in markedly increased scores on MMPI scales (hypochondriasis, schizophrenia, pure hypochondriasis, pure schizophrenia, emotional exclusion, and perception oddity), which closely correlated with clinical somatosensory symptoms. In clean-up workers, somatosensory disorders were significantly associated with hypochondriac and schizophrenic-like symptoms. The latencies (LPs) of main SSEP components—N20, P25, N140, P300, and N400—were increased and their amplitudes decreased in subjects exposed to radiation. Their SSEPs had significant topographical deviations in the left temporoparietal area: the contralateral LPs were increased, whereas the contralateral amplitudes of the thalamocortical N20 component and the cortical P25 component were decreased as compared to normal values. Somatosensory disorders and hypochondriac and schizophrenic symptoms were significantly correlated with changes in the SSEPs. The decrease in the N20 amplitude and increase in the P25 latency in the left temporoparietal area were dose-dependent. The results suggest cerebral rather than peripheral origin of ostealgic syndrome and other somatosensory disorders in the participants of the Chernobyl clean-up. These disorders are associated with radiation-induced dysfunction of the corticolimbic structures of the left—dominant—hemisphere. It is suggested that somatosensory disorders in patients exposed to low doses of radiation can be considered as manifestations of chronic fatigue syndrome /fibromyalgia, whereas schizoform organic brain lesions manifest themselves after exposure to a radiation dose of 0.3–0.5 Gy.

URL: http://link.springer.com/article/10.1023%2FA%3A1022069022557#

EEG source analysis of chronic fatigue syndrome

Author: Flor-Henry P., Lind J.C., Koles Z.J.

Reference: Psychiatry Res. — 2010. — Vol. 181, № 2. — P. 155–164.

Keywords: chronic fatigue syndrome, EEG

Abstract: Sixty-one dextral, unmedicated women with chronic fatigue syndrome (CFS) diagnosed according to the Fukuda criteria (1994) and referred for investigation by rheumatologists and internists were studied with quantitative EEG (43 channels) at rest with eyes open and during verbal and spatial cognitive activation. The EEGs from the patients were compared with recordings from 80 dextral healthy female controls. Only those subjects who could provide 20 1-s artefact-free segments of EEG were admitted into the study. The analysis consisted of the identification of the spatial patterns in the EEGs that maximally differentiated the two groups and the estimation of the cortical source distributions underlying these patterns. Spatial patterns were analyzed in the alpha (8-13Hz) and beta (14-20Hz) bands and the source distributions were estimated using the Borgiotti-Kaplan BEAMFORMER algorithm. The results indicate that the spatial patterns identified were effective in separating the two groups, providing a minimum correct retrospective classification rate of 72% in both frequency bands while the subjects were at rest to a maximum of 83% in the alpha band during the verbal cognitive condition. Underlying cortical source distributions showed significant differences between the two groups in both frequency bands and in all cognitive conditions. Lateralized cortical differences were evident between the two groups in the both frequency bands during both the verbal and spatial cognitive conditions. During these active cognitive conditions, the CFS group showed significantly greater source-current activity than the controls in the left frontal-temporal-parietal regions of the cortex.

URL: http://www.ncbi.nlm.nih.gov/pubmed/20006474

Chronic fatigue syndrome – a disease with a thousand names

Author: K.N. Loganovsky

Reference: Укр. мед. часопис. (Ukrainian Medical Magazine), 1998

Abstract: A well known article on the subject, yet without details on the web. For detailed information on the article contact the National Scientific Center for Radiation Medicine of Ukraine. The center’s home page is: http://www.national.rcrm.net.ua/index.php/en/