Abnormal Eeg Patterns in Treatment-Resistant Schizophrenic Patients

Abstract

This study was conducted in order to compare the EEG patterns of schizophrenics who do not respond to typical neuroleptics with those who do respond under typical neuroleptic medication and a group of controls. Absolute (AP) and relative power (RP), and inter- and intrahemispheric correlations were calculated. Nonresistant schizophrenics showed lower delta RP, higher alpha 1 AP and RP and higher correlation between prefrontal areas than the resistant ones and controls. Resistant schizophrenics showed lower alpha 2 RP, lower beta 1 and beta 2 in temporal but higher beta 2 AP and RP in occipital derivations, and higher intrahemispheric correlation between Fp2 and F4 and lower between F8 and T4 than the nonresistant and controls. The resistants also showed a higher antero-posterior beta 1 and beta 2 index than the controls. We concluded that the EEG pattern showed by the nonresistants may be associated with their good neuroleptic response that was not present in the resistant schizophrenics.

Magnetic Resonance Imaging Predictors of Treatment Response in First-Episode Schizophrenia

“…For example, Molina et al 33 reported that clozapine treatment was associated with increased occipital metabolism, including primary and association visual cortex, and additionally, that changes in positive symptoms correlated with increased activity in visual regions. In addition, Ramos et al 34 reported that treatment-resistant patients with schizophrenia had abnormal electroencephalographic (EEG) patterns in the occipital region. The purported mechanism through which the occipital gray matter could play a role in treatment response was not addressed in the present study, but animal data indicate that administration of antipsychotics is associated with D2 upregulation in all the major brain lobules, including the occipital lobe 35 as well as an increase in nerve growth factor in the occipital cortex.…”

Brain electrical activity changes in treatment refractory schizophrenics after olanzapine treatment

“…Furthermore, goodR showed higher values of alpha1 since the pretreatment session that could be related to a better brain functional state that allowed them to respond to OLZ. This interpretation could be supported by previous results that showed that nonrefractory had higher alpha1 values than refractory schizophrenics under typical neuroleptics (Ramos et al, 2001a). On the other hand, Miyauchi et al (1990) have reported an increase of beta activity in nonmedicated schizophrenics that has been interpreted as an evidence of cortical excitability and Kemali et al (1992) found a reduction of fast beta after 28 days of treatment with haloperidol.…”

“…On the other hand, a different brain electrical activity (EEG) pattern was observed in TRS patients in comparison to good responders (Ramos et al, 2001a) and in an emotional recognition task, TRS showed higher deficits than good responders correlated with neuroleptic doses (Ramos et al, 2001b).…”

“…Good responders had higher alpha power than TRS under typical neuroleptic medication. Also, TRS showed lower alpha2, lower beta1 and beta2 in temporal but higher beta2 in occipital derivations, and higher intrahemispheric correlation between Fp2 and F4 and lower between F8 and T4 than the nonresistant and controls (Ramos et al, 2001a).…”

“…Coherent activity might provide an invaluable tool to evaluate brain functional organization in schizophrenia since functional uncoupling of different neural networks involved in cognitive, affective and behavioral processes has been postulated in this psychopathology (Andreasen, 2001). Some authors have controversially reported an increase or a decrease of interhemispheric coherence, however, decreased intrahemispheric coherence has generally been found in schizophrenics (Flor-Henry and Koles, 1984;John et al, 1994;Merrin and Floyd, 1992;Nagase et al, 1992;Ramos et al, 2001a). John et al (1994) suggested that the low coherence between anterior and posterior regions may indicate a poor access of sensory information to regions concerned with evaluation of sensations.…”