ORIGINAL RESEARCH Pituitary volumes are changed in patients with conversion disorder Murad Atmaca & Sema Baykara & Osman Mermi & Hanefi Yildirim & Unsal Akaslan Published online: 16 April 2015 # Springer Science+Business Media New York 2015 Abstract Our study group previously measured pituitary vol- umes and found a relationship between somatoform disoders and pituitary volumes. Therefore, in conversion disorder, an- other somatoform disorder, we hypothesized that pituitary gland volumes would be reduced. Twenty female patients and healthy controls were recruited to the present investiga- tion. The volumes of the pituitary gland were determined by using a 1.5 Tesla magnetic resonance scanner. We found that the pituitary gland volumes of the patients with conversion disorder were significantly smaller than those of healthy con- trol subjects. In the patients with conversion disorder but not in the healthy control group, a significant negative correlation between the duration of illness and pituitary gland volume was determined. In summary, in the present study, we suggest that the patients with conversion disorder have smaller pitui- tary volumes compared to those of healthy control subjects. Further studies should confirm our data and ascertain whether volumetric alterations determined in the patients with conver- sion disorder can be changed with treatment or if they change over time. Keywords Pituitary gland . Volumetric . Conversion disorder . MRI Introduction Conversion disorder is characterized by loss or distortion of neurological function which is not accounted for by a real neurological condition (American Psychiatric Association 1994). It is classified as a somatoform disorder in the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) (American Psychiatric Association 1994). In the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition, the disorders has been named as functional neurolog- ical disorder (American Psychiatric Association 2013). Although conversion disorder is not very frequent in western societies, it is very common in eastern societies, as in our country (Pierloot and Ngoma 1988; Chandrasekaran et al. 1994). Although the psychodynamic nature of conversion disor- der is well-described, the exact neurobiological mechanism of it is not clear. In a neuroimaging study, Vuilleumier et al. (2001) examined patients with conversion disorder using sin- gle photon emission computerized tomography with 99m Tc- ECD and showed a decrease of regional cerebral blood flow in the thalamus and basal ganglia contralateral to the deficit, showing a functional disorder in striatothalamocortical cir- cuits controlling sensorimotor function and voluntary motor behavior. Our study group carried out a volumetric magnetic resonance imaging (MRI) study in female patients with con- version disorder. In that study the researchers determined that patients with conversion disorder had significantly smaller mean volumes of the left caudate nucleus, lentiform nucleus, right caudate nucleus, and thalamus compared to healthy con- trols (Atmaca et al. 2006). In somatization disorder and hypo- chondriasis, we found smaller pituitary gland volumes previ- ously (Atmaca et al. 2010, 2011). Therefore, in conversion disorder, another somatoform disorder, we planned to exam- ine pituitary gland volumes and hypothesized that pituitary Brain Imaging and Behavior (2016) 10:92–95 DOI 10.1007/s11682-015-9368-6 M. Atmaca (*) : S. Baykara : O. Mermi Department of Psychiatry, Firat University, School of Medicine, Elazig 23119, Turkey e-mail: matmaca_p@yahoo.com H. Yildirim : U. Akaslan Department of Radiology, Firat University, School of Medicine, Elazig, Turkey