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Cognitive and neurobiological alterations in electromagnetic hypersensitive patients: results of a case-control study

Published online by Cambridge University Press:  26 March 2008

M. Landgrebe
Affiliation:
Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Regensburg, Regensburg, Germany
U. Frick
Affiliation:
Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Regensburg, Regensburg, Germany Carinthia Tech Institute, University of Applied Sciences, Villach, Austria
S. Hauser
Affiliation:
Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Regensburg, Regensburg, Germany
B. Langguth
Affiliation:
Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Regensburg, Regensburg, Germany
R. Rosner
Affiliation:
Department of Psychology, University of Munich, Munich, Germany
G. Hajak
Affiliation:
Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Regensburg, Regensburg, Germany
P. Eichhammer*
Affiliation:
Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Regensburg, Regensburg, Germany
*
*Address for correspondence: Professor P. Eichhammer, M.D., Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Regensburg, Universitaetsstrasse 84, 93053 Regensburg, Germany. (Email: [email protected])

Abstract

Background

Hypersensitivity to electromagnetic fields (EMF) is frequently claimed to be linked to a variety of non-specific somatic and neuropsychological complaints. Whereas provocation studies often failed to demonstrate a causal relationship between EMF exposure and symptom formation, recent studies point to a complex interplay of neurophysiological and cognitive alterations contributing to symptom manifestation in electromagnetic hypersensitive patients (EHS). However, these studies have examined only small sample sizes or have focused on selected aspects. Therefore this study examined in the largest sample of EHS EMF-specific cognitive correlates, discrimination ability and neurobiological parameters in order to get further insight into the pathophysiology of electromagnetic hypersensitivity.

Method

In a case-control design 89 EHS and 107 age- and gender-matched controls were included in the study. Health status and EMF-specific cognitions were evaluated using standardized questionnaires. Perception thresholds following single transcranial magnetic stimulation (TMS) pulses to the dorsolateral prefrontal cortex were determined using a standardized blinded measurement protocol. Cortical excitability parameters were measured by TMS.

Results

Discrimination ability was significantly reduced in EHS (only 40% of the EHS but 60% of the controls felt no sensation under sham stimulation during the complete series), whereas the perception thresholds for real magnetic pulses were comparable in both groups (median 21% versus 24% of maximum pulse intensity). Intra-cortical facilitation was decreased in younger and increased in older EHS. In addition, typical EMF-related cognitions (aspects of rumination, symptom intolerance, vulnerability and stabilizing self-esteem) specifically differentiated EHS from their controls.

Conclusions

These results demonstrate significant cognitive and neurobiological alterations pointing to a higher genuine individual vulnerability of electromagnetic hypersensitive patients.

Type
Original Articles
Copyright
Copyright © 2008 Cambridge University Press

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References

Bailer, J, Witthoft, M, Bayerl, C, Rist, F (2007). Syndrome stability and psychological predictors of symptom severity in idiopathic environmental intolerance and somatoform disorders. Psychological Medicine 37, 271281.CrossRefGoogle ScholarPubMed
Barsky, AJ, Borus, JF (1999). Functional somatic syndromes. Annals of Internal Medicine 130, 910921.Google ScholarPubMed
Bergdahl, J, Bergdahl, M (2001). Environmental illness: evaluation of salivary flow, symptoms, diseases, medications, and psychological factors. Acta Odontologica Scandinavica 59, 104110.CrossRefGoogle ScholarPubMed
Bleichhardt, G, Timmer, B, Rief, W (2004). Cognitive-behavioural therapy for patients with multiple somatoform symptoms – a randomised controlled trial in tertiary care. Journal of Psychosomatic Research 56, 449454.CrossRefGoogle ScholarPubMed
Bornschein, S, Hausteiner, C, Zilker, T, Forstl, H (2002). Psychiatric and somatic disorders and multiple chemical sensitivity (MCS) in 264 ‘environmental patients’. Psychological Medicine 32, 13871394.CrossRefGoogle ScholarPubMed
Buysse, DJ, Reynolds, CF, Monk, TH, Berman, SR, Kupfer, DJ (1989). The Pittsburgh Sleep Quality Index: a new instrument for psychiatric practice and research. Psychiatry Research 28, 193213.CrossRefGoogle ScholarPubMed
Ciccone, DS, Natelson, BH (2003). Comorbid illness in women with chronic fatigue syndrome: a test of the single syndrome hypothesis. Psychosomatic Medicine 65, 268275.CrossRefGoogle ScholarPubMed
Ferreri, F, Curcio, G, Pasqualetti, P, De Gennaro, L, Fini, R, Rossini, PM (2006). Mobile phone emissions and human brain excitability. Annals of Neurology 60, 188196.CrossRefGoogle ScholarPubMed
Feychting, M, Ahlbom, A, Kheifets, L (2005). EMF and health. Annual Review of Public Health 26, 165189.CrossRefGoogle ScholarPubMed
Frick, U, Kharraz, A, Hauser, S, Wiegand, R, Rehm, J, Kovatsits, U, Eichhammer, P (2005). Comparison perception of singular transcranial magnetic stimuli by subjectively electrosensitive subjects and general population controls. Bioelectromagnetics 26, 287298.CrossRefGoogle ScholarPubMed
Frick, U, Mayer, M, Hauser, S, Binder, H, Rosner, R, Eichhammer, P (2006). Development of a German-language measuring instrument for ‘electrical smog complaints’ [in German]. Umweltmedizin in Forschung und Praxis 11, 1122.Google Scholar
Frick, U, Meyer, M, Hauser, S, Eichhammer, P (2004). Feasibility study: verification of the complaints of ‘electro-sensitives’ before and after reconstruction [Report, in German]. German Federal Ministry for the Environment, Nature Conservation, and Nuclear Safety: Berlin.Google Scholar
Harlacher, U, Schahn, J (1998). ‘Electrical sensitivity’ – a psychological problem? In Environment and Health. The Connection of Ecological and Health Beginnings [in German] (ed. Kals, E.), pp. 151196. Psychologie Verlagsunion: Weinheim.Google Scholar
Hiller, W, Fichter, MM, Rief, W (2003). A controlled treatment study of somatoform disorders including analysis of healthcare utilization and cost-effectiveness. Journal of Psychosomatic Research 54, 369380.CrossRefGoogle ScholarPubMed
Hillert, L, Berglind, N, Arnetz, BB, Bellander, T (2002). Prevalence of self-reported hypersensitivity to electric or magnetic fields in a population-based questionnaire survey. Scandinavian Journal of Work, Environment and Health 28, 3341.CrossRefGoogle ScholarPubMed
Hillert, L, Kolmodin, HB, Dolling, BF, Arnetz, BB (1998). Cognitive behavioural therapy for patients with electric sensitivity – a multidisciplinary approach in a controlled study. Psychotherapy and Psychosomatics 67, 302310.CrossRefGoogle Scholar
Kammer, T, Beck, S, Thielscher, A, Laubis-Herrmann, U, Topka, H (2001). Motor thresholds in humans: a transcranial magnetic stimulation study comparing different pulse waveforms, current directions and stimulator types. Clinical Neurophysiology 112, 250258.CrossRefGoogle ScholarPubMed
Kujirai, T, Caramia, MD, Rothwell, JC, Day, BL, Thompson, PD, Ferbert, A, Wroe, S, Asselman, P, Marsden, CD (1993). Corticocortical inhibition in human motor cortex. Journal of Physiology 471, 501519.CrossRefGoogle ScholarPubMed
Landgrebe, M, Hauser, S, Langguth, B, Frick, U, Hajak, G, Eichhammer, P (2007). Altered cortical excitability in subjectively electrosensitive patients: results of a pilot study. Journal of Psychosomatic Research 62, 283288.CrossRefGoogle ScholarPubMed
Levallois, P (2002). Hypersensitivity of human subjects to environmental electric and magnetic field exposure: a review of the literature. Environmental Health Perspectives 110 (Suppl.), S613S618.Google ScholarPubMed
Levallois, P, Neutra, R, Lee, G, Hristova, L (2002). Study of self-reported hypersensitivity to electromagnetic fields in California. Environmental Health Perspectives 110 (Suppl. 4), 619623.CrossRefGoogle ScholarPubMed
Liepert, J, Schwenkreis, P, Tegenthoff, M, Malin, JP (1997). The glutamate antagonist riluzole suppresses intracortical facilitation. Journal of Neural Transmission 104, 12071214.CrossRefGoogle ScholarPubMed
Lyskov, E, Sandstrom, M, Hansson, MK (2001). Neurophysiological study of patients with perceived ‘electrical hypersensitivity’. International Journal of Psychophysiology 42, 233241.CrossRefGoogle ScholarPubMed
Moll, GH, Heinrich, H, Rothenberger, A (2001). Transcranial magnetic stimulation in child and adolescent psychiatry: excitability of the motor system in tic disorders and/or attention deficit hyperactivity disorders [in German]. Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie 29, 312323.CrossRefGoogle ScholarPubMed
Nelson, CB, Kessler, RC, Mroczek, D (2001). Scoring the World Health Organization's Composite International Diagnostic Interview Short Form. World Health Organization: Geneva.Google Scholar
Peinemann, A, Lehner, C, Conrad, B, Siebner, HR (2001). Age-related decrease in paired-pulse intracortical inhibition in the human primary motor cortex. Neuroscience Letters 313, 3336.CrossRefGoogle ScholarPubMed
Rief, W, Hillert, W, Heuser, J (1997). SOMS – A Screening Procedure for the Identification of Persons with Somatoform Disturbances [in German]. Hogrefe: Göttingen.Google Scholar
Rossini, PM, Barker, AT, Berardelli, A, Caramia, MD, Caruso, G, Cracco, RQ, Dimitrijevic, MR, Hallett, M, Katayama, Y, Lucking, CH (1994). Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application. Report of an IFCN committee. Electroencephalography and Clinical Neurophysiology 91, 7992.CrossRefGoogle ScholarPubMed
Rubin, GJ, Das, MJ, Wessely, S (2005). Electromagnetic hypersensitivity: a systematic review of provocation studies. Psychosomatic Medicine 67, 224232.Google ScholarPubMed
Rubin, GJ, Das, MJ, Wessely, S (2006). A systematic review of treatments for electromagnetic hypersensitivity. Psychotherapy and Psychosomatics 75, 1218.CrossRefGoogle ScholarPubMed
Sandstrom, M, Lyskov, E, Hornsten, R, Hansson, MK, Wiklund, U, Rask, P, Klucharev, V, Stenberg, B, Bjerle, P (2003). Holter ECG monitoring in patients with perceived electrical hypersensitivity. International Journal of Psychophysiology 49, 227235.CrossRefGoogle ScholarPubMed
Schwenkreis, P, Witscher, K, Janssen, F, Addo, A, Dertwinkel, R, Zenz, M, Malin, JP, Tegenthoff, M (1999). Influence of the N-methyl-d-aspartate antagonist memantine on human motor cortex excitability. Neuroscience Letters 270, 137140.CrossRefGoogle ScholarPubMed
Stenberg, B, Bergdahl, J, Edvardsson, B, Eriksson, N, Linden, G, Widman, L (2002). Medical and social prognosis for patients with perceived hypersensitivity to electricity and skin symptoms related to the use of visual display terminals. Scandinavian Journal of Work, Environment and Health 28, 349357.Google Scholar
Wassermann, EM (2002). Variation in the response to transcranial magnetic brain stimulation in the general population. Clinical Neurophysiology 113, 11651171.CrossRefGoogle ScholarPubMed
Ziemann, U, Rothwell, JC, Ridding, MC (1996). Interaction between intracortical inhibition and facilitation in human motor cortex. Journal of Physiology 496,873881.CrossRefGoogle ScholarPubMed