The two forms of obsessive-compulsive disorder (OCD), idiopathic and acquired, have been linked to abnormalities in the fronto-striato-thalamo-cortical circuitry, involving the orbitofrontal cortex, anterior cingulate cortex, thalamus, and striatum. Accumulating evidence indicates that damage to other brain regions (ie, temporal lobes) is also implicated in the pathogenesis of both types of OCD. In addition, some discrete OCD symptoms have received less attention because of their presumed low occurrence and difficultly of categorization. Among these, one intriguing and potentially severe type of obsessive thinking is the so-called “need to know” (NtK), which is a strong urge to access certain information, particularly proper names. In some patients, this monosymptomatic presentation may constitute the major feature of OCD. Here we report the cases of two patients who developed NtK obsessions with tenacious time-consuming, answer-seeking compulsions as the only or more disabling symptomatology in association with malignant tumors involving the right temporal lobe and connected fronto-subcortical circuits.
*Cognitive Neurology and Aphasia Unit, Institute of Biomedical Research in Malaga
†Department of Psychobiology and Methodology of Behavioural Sciences, Faculty of Psychology
§Molecular Imaging Unit, Medical-Sanitary Research Centre General Foundation, University of Malaga, Malaga, Spain
‡Service of Neuropsychology, Hospital Quirón, Malaga, Spain
∥Department of Psychiatry, Radiology and Public Health, Molecular Imaging and Medical Physics Group, University of Compostela, Galicia, Spain
¶Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine, Barcelona, Spain
#Faculty of Education, International University of La Rioja, Logroño, Spain
Supported in part by PhD scholarships from the Spanish Ministry of Education, Culture and Sport under the Training University Lecturers Program (Formación de Profesorado Universitario [FPU]) to L.E. (FPU17/04136), F.J.L.-G. (FPU17/04470), and M.J.T.-P. (FPU14/04021); and by a postdoctoral grant from the University of Malaga to D.L.-B.
The authors declare no conflicts of interest.
Correspondence: Marcelo L. Berthier, MD, PhD, Unidad de Neurología Cognitiva y Afasia, Centro de Investigaciones Médico-Sanitarias, Universidad de Málaga, Marqués de Beccaria 3, 29010, Málaga, España (email: email@example.com).
Received May 22, 2018
Accepted February 1, 2019