Comparison of saccade, smooth pursuit and optokinetic nystagmus among Filipino patients diagnosed with schizophrenia, their siblings without schizophrenia and controls using the electronystagmogram: a pilot study at the Santo Tomas Hospital
- Author:
Raya-Ampil Encarnita
;
Eduardo-Illaga Mary Warren
;
Conde Bernardo L.
;
de los Santos Ronald
;
Martinez Norberto V.
- Publication Type:Journal Article
- From:
The Philippine Journal of Psychiatry
2011;33(2):3-7
- CountryPhilippines
- Language:English
-
Abstract:
Objectives:
The structural abnormality implicated in schizophrenia was supported by eye movement abnormalities, which were considered biological or trait markers of this psychiatric disorder. We aimed to establish the presence of these changes in schizophrenia by comparing the smooth pursuit eye movement latency, fixed amplitude saccade latency and symmetry of optokinetic nystagmus using the electronystagmogram among Filipino patients diagnosed with schizophrenia, their siblings without schizophrenia and controls who were neither related to the patient nor diagnosed with schizophrenia.
Methods:
Included were twenty patients 18-40 years old diagnosed of schizophrenia based on the DSM-IV Criteria, their siblings and twenty controls. All subjects underwent electronystagmography at the Ear Center, University of Santo Tomas Hospital where the following were measured: fixed amplitude saccade latency; horizontal smooth pursuit latency and symmetry of optokinetic nystagmus. The values obtained were then analyzed using paired t-test and two way ANOVA.
Results:
There was a significant difference in the latency of the fixed amplitude saccade and horizontal smooth pursuit among the three groups. PAtients with schizophrenia had the most delayed latency followed by their siblings. No delay was noted in controls. Significant asymmetry of the optokinetic nystagmus in schizophrenic patients was noted. Abnormalities present in the healthy siblings of patients indicated their latent vulnerability towards this disease.
Conclusion:
The findings of the study further strengthened the anatomical substrate of schizophrenia. These eye movement abnormalities are localized in the parietal and frontal cortex. These are the same areas that are necessary for attentional symmetry, for minimizing distractibility and maintaining the focus of attention on task relevant stimuli which are impaired in patients with schizophrenia.
