Heightened sensitivity to somatosensory stimuli in anorexia nervosa: An exploratory study with the SASTCA scale

Abstract

Objectives: To analyse the presence of heightened sensory sensitivity in patients with anorexia nervosa, which seems similar but not identical to that described in patients with unexplained somatic symptoms or body dysmorphic disorder. Methods: We developed a sensory sensitivity scale in eating disorders (SASTCA), which measures the intensity of the response to specific somatosensory stimuli. The scale was completed by 48 patients with anorexia and a control group of 31 participants matched in age, sex and social and educational level. The results were compared with those obtained with the Barsky Somatosensory Amplification Scale (SSAS). Results: The reliability (Cronbach’s/alpha, 0.946; Guttman/split-half, 0.936) and validity (ROC, 0.933) of the SASTCA scale are indicative of its high sensitivity and specificity. The anorexia group had a significantly higher mean score on the SASTCA scale than the control group (p<.001). Similarly, the patients with anorexia had a significantly higher mean value on the SSAS than the participants in the control group (p<.01), although the difference was less extreme. The 2 scales correlated positively (r=.634). Discussion: These preliminary results suggest the presence in Anorexia of heightened sensory sensitivity which differs from the sensitivity of the control group. This sensitivity has a significant relationship with that described in patients with somatic complaints about health (SSD) or appearance (BDD). Could this heightened sensory sensitivity help us to explain the process of forming the distorted body self-concept (I´m fat, sick, ugly) in all these patients? Once its presence has been confirmed in other patients with anorexia, their relatives and other patients with somatic disorders this heightened sensitivity could constitute the somatic endophenotype of anorexia?Objetivo: destacar la presencia de una sensibilidad extrema hacia estímulos externos e internos (Amplificación Somatosensorial) en pacientes con Anorexia, similar pero no idéntica, a la descrita en pacientes con unexple somatic symtoms. Método: Se ha elaborado una escala de Amplificación Somatosensorial para Trastornos de la Conducta Alimentaria, (SASTCA), que mide la intensidad de la respuesta hacia estímulos somatosensoriales específicos. La escala ha sido cumplimentada por un grupo de 48 pacientes anoréxicas y un grupo control de 31 sujetos emparejados en edad, sexo y nivel socioeducativo. Los resultados se han comparado con los obtenidos en la escala SSAS de Barsky. Resultados: La Fiabilidad (Alfa de Cronbach 0,946; dos mitades de Guttman 0,936) y la Validez (ROC, 0,933), son indicativas de elevada sensibilidad y especificidad de la escala SASTCA. El grupo de pacientes presenta una media 58,73 12,38, significativamente superior al grupo control 37,81 7,47, (α=0,001). Las pacientes presentan en la escala SSAS una media 31,21 6,68 significativamente superior al grupo control 26,58 5,49 (α=0,01), aunque la diferencia es menos extremada. Ambas escalas correlacionan positivamente. 0,634 Conclusiones: Los resultados sugieren la presencia en AN. de una sensibilidad extrema hacia estímulos somatosensoriales. ¿Podria esta elevada sensibilidad sensorial ayudarnos a explicar el proceso de formación del auto-concepto distorsionado (“gordo, enfermo, feo”) de estos pacientes? De confirmar su presencia en otras muestras de pacientes con anorexia, en sus familiares y en diferentes pacientes somatomorfos o TCA, esta elevada sensibilidad podría considerarse el endofenotipo somatomorfo del trastorno anoréxico.