Eye-hand preference dissociation in obsessive-compulsive disorder and dyslexia

Arq Neuropsiquiatr 2002;60(2-A):242-245 EYE-HAND PREFERENCE DISSOCIATION IN OBSESSIVE-COMPULSIVE DISORDER AND DYSLEXIA Marilena Occhini Siviero1, Eliana Oliveira Rysovas1, Yara Juliano2, José Alberto Del Porto3, Paulo Henrique Ferreira Bertolucci1 ABSTRACT - Dyslexia may be a development disturbance in which there are alterations in visual-spatial and visual-motor processing, while obsessive-compulsive disorder (OCD) is a psychiatric disease in which there are alterations in memory, executive function, and visual-spatial processing. Our hypothesis is that these disturbances may be, at least partially, the result of a crossed eye and hand preference. In the present study 16 controls, 20 OCD (DSM-IV criteria) and 13 dyslexic adults (Brazilian Dyslexia Association criteria) were included. All had a neurological examination, the Yale-Brown scale for obsessive-compulsive symptoms application and the Zazzó evaluation for laterality, abridged by Granjon. Results showed a right hand preference for 100% of controls, 84.6% of dyslexics, and 75% of OCD patients and a right eye preference for 73.3% of controls, 69.2% of dyslexics, and 35% of OCD patients. The left eye preference was significantly higher in OCD when compared with the two other groups (p = 0.01) and the left hand preference of OCD patients (25%) was also significant when compared to Brazilian population (4%) or British population (4.5%). It is possible that this crossed preference may be partially the reason for visual-spatial and constructive disturbances observed in OCD. KEY WORDS: obsessive-compulsive disorder, dyslexia, eye preference, laterality, handedness, procedural memory. Dissociação da preferência ocular e manual em pacientes com transtorno obsessivo-compulsivo e dislexia RESUMO - A dislexia pode resultar de distúrbio do desenvolvimento e apresenta alterações no processamento visuo-espacial e visuo-motor, enquanto o transtorno obsessivo compulsivo (TOC) é uma alteração psiquiátrica na qual podem ocorrer alterações de memória, função executiva e visuo-espacial. Nossa hipótese é que parte destes distúrbios pode decorrer da preferência ocular e manual cruzadas. Foram avaliados 16 indivíduos normais, 20 pacientes com TOC, (critérios da DSM-IV) e 13 adultos disléxicos (critérios da Associação Brasileira de Dislexia). Todos passaram por exame neurológico, avaliação de sintomas obsessivos-compulsivos pela escala Yale-Brown e pela bateria para avaliação da lateralidade de Zazzó versão reduzida de Granjon. Os resultados mostraram a preferência pela mão direita de 84,6% nos disléxicos, 100% nos normais e 80% em TOC. A preferência ocular pelo olho direito foi de 69,2% nos disléxicos, 73,3% nos normais e apenas 35% nos TOC, com significância de p=0,01 quando comparada aos outros dois grupos.A preferência da mão esquerda pelo grupo de pacientes com TOC (25%) foi também significante quando comparada com os resultados da população brasileira em geral (4%) ou da população inglesa (4,5%). É possível que esta dominância cruzada seja responsável, em parte, pelas dificuldades visuo-espaciais e construcionais observadas no TOC. PALAVRAS-CHAVE: transtorno obsessivo compulsivo, dislexia, preferência ocular, lateralidade, preferência manual, memória procedural. Attention deficits and hyperactivity disorder (ADHD) in children have been related to obsessivecompulsive disorder (OCD) in adults, but the attention deficit can also be present in some dyslexic children. ADHD is related to the spectrum of movement disorders as Tourette syndrome and OCD1. It is known that OCD subjects have impairment in visual-spatial skills2-10 related to the right hemisphere, and dyslexics are impaired in writing and reading, preponderantly a left hemisphere task1. As dyslexics sometimes have a cross-dominance of hand-eye-foot, we became interested in knowing which could be OCD laterality. For the assessment of laterality there are some questionnaires, including Edinburgh Handedness Inventory12 for adults, in which subjects are asked to indicate their preferred hand for writing, drawing, throwing, cutting with scissors or brushing. However, we wanted to acced laterality through behavioral tasks, observing while the patient is performing the action and the time Federal University of São Paulo School of Medicine, São Paulo SP, Brazil: 1Department of Neurology and Neurosurgery; 2Department of Mental Health; 3Department of Psychiatry. This research was supported by FAPESP (grant 98/04496-9 to MOS). Received 26 July 2001, received in final form 12 November 2001. Accepted 14 November 2001. Dra. Marilena Occhini Siviero - Rua Oscar Freire, 1234/111 - 01426-000 São Paulo SP – Brasil. FAX: 55 11 3085 9801. E-mail: Arq Neuropsiquiatr 2002;60(2-A) spended to do, as assessed by Zazzó13 with children. When questionnaires are used, conscious processes are acceded with the interference of declarative memory, and they could not be the same as when we are performing the task. The performance by the repetition of motor tasks, is a procedural approach with non-conscious14 processes. We wanted to observe implicitly which hand, eye or foot would be used by OCD patients. Besides the impairment in visualspatial skills, OCD patients are also impaired in executive tasks2,7,10,15-20. Merckelbach et al21 applying questionnaires in patients with anxiety disorders found 83% of right hand dominance, 10% of left hand dominance and 6.5% with ambidextricity, but without assessment of eye or foot preference. Annett22 suggests a theory of the origin of hand preference involving three factors: a) an accidental variation in the development of the two sides of the body; b) a systematic bias to the right hand in man, also called the genetic theory of with the right shift that predicts until 12.5% of left handedness and c) sociocultural factors affecting the expression of left preference. In none of these studies we found a relation of eye preference with psychiatric disorders. We are not aware of any work to assess hand-eye-foot dominance in OCD with performance tasks measuring the time to execute a manual task. The objective of this study was to evaluate eye and hand preference in controls, OCD and dyslexics, with the hypothesis that OCD patients could show a reverse pattern of laterality when compared with dyslexics. METHOD Subjects There were two experimental groups, one with 13 dyslexic adults, diagnosed by the Brazilian Association of Dyslexia accordingly with international criteria and another with 20 OCD patients, diagnosed by DSM-IV (APA, 1993) criteria by a psychiatrist. As a comparison group, 16 healthy controls were included, without neurological or psychiat- 243 ric disordes, matched by gender, age and education. (Table 1).The study was previously submitted and approved by the Ethic Committee on the Federal University of São Paulo, accordingly with international guidelines on research in humans. Measures Questionnaire - The Yale Brown Obsessive and Compulsive Scale23 (...truncated)