All in the mind? The neural correlates of unexplained physical symptoms

Sean Spence is Professor of General Adult Psychiatry at the University of Sheffield (Academic Clinical Psychiatry, University of Sheffield, The Longley Centre, Norwood Grange Drive, Sheffield S5 7JT, UK. Email: s.a.spence{at}sheffield.ac.uk). He studied medicine at Guy’s Hospital, London, then worked in several medical specialties before training in psychiatry at London’s Charing Cross Hospital, undertaking a Medical Research Council training fellowship at Hammersmith Hospital and a De Witt Wallace travelling fellowship to Cornell University, New York. His research concerns the cognitive neurobiology of volition.

Physical symptoms with no medical explanation are commonly experienced by healthy people and those attending clinics. Psychiatrists see such patients in liaison settings and clinics for those with psychotic and affective disorders. The pathophysiology remains obscure; physical investigations are usually performed to exclude pathology rather than elucidate dysfunction. However, modern neuroimaging has allowed the study of nervous system structure and function. Although there are few diagnostically specific findings, patterns of association have emerged: where action is impeded (certain forms of conversion disorder and chronic fatigue syndrome) frontal systems of the brain are often implicated; when subjective awareness of the body is disturbed (passivity phenomena and anorexia nervosa) temporo-parietal cortices appear to be dysfunctional. The caudate nuclei (components of the frontal executive circuit) are implicated in a variety of syndromes (including body dysmorphic disorder, somatisation and chronic fatigue). The brain may be viewed as a cognitive neurobiological entity, crucially oriented towards action (for survival). Psychiatric syndromes that have an impact on bodily awareness signal dysfunction within systems representing that body and its performance in time and space.