129 S. Cüreo¤lu, A. Alt›nda¤, Ü. Osma, fi. Özen, F. Oktay, F. Meriç , ‹. Topçu Klinik Psikofarmakoloji Bülteni, Cilt: 10, Say›: 3, 2000 / Bulletin of Clinical Psychopharmacology, Vol: 10, N.: 3, 2000 INTRODUCTION C onversion disorder is characterized by the pres- ence of one or more neurological or general medical symptoms that cannot be explained by a known neurological or medical disorder (1). Several studies have reported that 5 to 15 percent of psy- chiatric consultations in a general hospital involve patients with conversion disorder diagnosis (2). This disorder frequently occurs in the context of other psychopathology and also tends to have a significant association with CNS disease. According to some researchers, organic CNS dysfunction is a particular- ly common correlate of conversion disorder (3). Of these, about half had pathology directly or system- atically affecting the brain (3). It was suggested that excessive cortical arousal that sets off negative feed- back loops between the cerebral cortex and the brainstem reticular formation cause inhibition of the patient’s awareness of bodily sensation (2). The brainstem auditory evoked response (BAER) reflects electrophysiological activity of large numbers of neurons in the brainstem auditory pathway follow- ing acoustic stimulation. The various deflections in the response represent neural activity at different levels of the auditory brainstem. Waves I and II are Evaluation of Brainstem Auditory Evoked Responses in Patients With Conversion Disorders Sebahattin Cüreoğlu M.D. 1 , Abdurrahman Altındağ M.D. 2 , Üstün Osma M.D. 1 , Şakir Özen M.D. 2 , Faruk Oktay M.D. 1 , Faruk Meriç M.D. 1 , İsmail Topçu M.D.* 1 SUMMARY EVALUATION OF BRAINSTEM AUDITORY EVOKED RESPONS- ES IN PATIENTS WITH CONVERSION DISORDERS Objective: The aim of this study was to detect any suboptimal brainstem lesions in patients with conversion disorder. Methods: This study included 37 patients (25 female, 12 male) with conversion disorder. Control’s group included 30 healthy persons (22 female, 8 male). The diagnosis of conversion disorder was based on criteria of DSM IV. BAER was recorded at conventional and higher stimulus rate in these patients. The main BAER measurements analyzed were the I-III, III-V, and I-V interpeak intervals and the wave V amplitude. Results: There was significant difference for I-III (p<0,05), I-V (p<0,05) interpeak latencies between patient and controls groups at 10/s click rate. The only I-III interval differed significantly at 50/s click rate. Abnormal BAER result was seen in only one of 37 patients at the clicks of 10/s and 50/s, when the values exceed- ing 2.5 standard deviations above the means of the normal con- trols were considered abnormal. No significant correlation was found between diseased period and BAER latencies. Conclusion: The lower brainstem (cochlear nucleus, superior oli- vary complex and lateral lemniscus) has been affected in patients with conversion disorder. Key words: conversion disorders, brainstem, evoked potentials Bull Clin Psychopharmacol 2000;10:129-132 ÖZET KONVERS‹YONLU HASTALARDA BEY‹NSAPI UYARILMIfi ‹fi‹TME POTANS‹YELLER‹N‹N DE/ERLEND‹R‹LMES‹ Amaç: Konversiyonlu hastalarda suboptimal beyinsap› lezyon- lar›n› belirlemek. Yöntem: Bu çal›flma konversiyon bozuklu¤u tan›s› alan 37 hasta (25 kad›n, 12 erkek) üzerinde yap›ld›. Kontrol grubu yafl ve cins uyumlu 30 sa¤l›kl› bireyden (22 kad›n, 8 erkek) oluflturuldu. Konversiyon bozuklu¤u tan›s›, DSM IV kriterlerine göre konuldu. Bu hastalardan beyinsap› uyar›lm›fl iflitme potan- siyelleri konvansiyonel ve yüksek uyar› h›z›nda kaydedildi. Beyinsap› uyar›lm›fl iflitme potansiyellerinin de¤erlendirilmesi; I- III, III-V ve I-V interpik intervallerini ve V. Dalga amplitüdünün ölçümlerini kapsamaktad›r. Bulgular: Saniyede 10 klik h›z›nda I-III ve I-V interpik interval- lerinde fark mevcuttu (p<0,05). Saniyede 50 klik h›z›nda ise sadece I-III intervalinde fark gözlendi. Normal kontrol ortala- malar›n›n 2.5 kat› standart sapmas›n› aflan de¤erler anormal kabul edildi¤inde 37 hastan›n sadece birinde anormal beyin- sap› uyar›lm›fl iflitme potansiyeli gözlendi. Sonuç: Konversiyonlu hastalarda alt beyin sap› (koklear nükleus, superior oliver kompleks ve lateral lemnisküs) etkilenimi vard›r. Anahtar sözcükler: konversiyon bozuklu¤u, beyinsap›, uyar›lm›fl potansiyeller Klinik Psikofarmokoloji Bülteni 2000;10:129-132 Yaz›flma Adresi / Address reprint requests to: Sebahattin CÜREO/LU M.D., Dicle Üniversitesi T›p Fak. KBB Anabilim Dal›, 21280, Diyarbak›r- TURKEY Phone :+90 412 2488001 Fax:+ 90 412 2488520 E-Mail: scureoglu@hotmail.com 1 Dicle University, School of Medicine, Department of Otorhinolaryngology - Diyarbak›r, 2 Dicle University, School of Medicine, Department of Psychiatry- Diyarbak›r