SACCADIC ABNORMALITIES IN PSYCHOTIC-PATIENTS .2. THE ROLE OF NEUROLEPTIC TREATMENT

The effects of dopamine-antagonistic neuroleptic (NL) medication on sa ccadic eye movements were compared in matched groups of 40 NL-treated and 18 NL-free schizophrenic patients and in 18 NL-treated and 14 NL-f ree bipolar affective patients. Manipulation of the saccadic paradigm yielded data on four types of saccade: those reflexively elicited by n ovel stimuli (REFLEX saccades), those directed towards the remembered location of a target now extinguished (REM) or towards the location wh ere a predictably alternating target is expected to appear (PRED), or ANTI saccades, directed away from the stimulus to the mirror image loc ation. Extensive psychiatric, neurological and neuropsychological asse ssments were also carried out on all subjects. The saccades of NL-trea ted patients, regardless of diagnosis, were less spatially accurate th an those of NL-free patients, with a greater tendency to fall short of the target when generated towards the locus of a mentally represented target. This effect was greatest with a predictably alternating targe t, especially during periods when target visibility was withdrawn, onl y a temporal cue remaining. This pattern of impairment which is also f ound in early stages of Parkinson's disease is likely to be due to def iciency of striatal dopamine. Its best clinical predictors were diseas e duration, and Webster-Parkinsonism scores. Failure to suppress refle xive saccades to the stimulus in the REM and ANTI paradigms were more closely associated with schizophrenia than with NL treatment and were best predicted by negative symptoms and Wisconsin perseverative errors , both of which are widely regarded as indicators of frontal lobe dysf unction.