Studies in Schizophrenia

Heath, Robert G.; Becker, Hal C.; Bersadsky, Leona; Corrigan, Robert M.; Epstein, Arthur W.; Founds, Warren L.; Bengochea, Francisco Garcia; Hendley, Charles D.; Hodes, Robert; Hogan, Charles C.; King, H. E.; Leach, Byron E.; Llewellyn, Raeburn C.; Mickle, Walter A.; Miller, William H.; Millsaps, Frederick F.; Monroe, Russell R.; Peacock, Samuel M.; Price, Tom; Sachs, Ernest; Strohmeyer, Florence B.; Weber, John J.; Young, Kathleen M.

doi:10.4159/harvard.9780674594548

Cited by 201 publications

(17 citation statements)

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“…3) indeed demonstrate increased theta power. This activation of high frequency areas might express itself through abnormal EEG spiking activity, as demonstrated in psychotic patients (Spiegel and Wycis, 1950;Heath, 1954). (4) The final step in the description of this syndrome is the proposed existence of an activation of high frequency (beta and gamma) cortical domains due to an asymmetrical corticocortical GABAergic collateral inhibition (Llinas et al, 1999.…”

Section: The Neuropsychiatric Thalamocortical Dysrhythmiamentioning

confidence: 99%

“…Indeed, electroencephalographic (EEG) (Spiegel and Wycis, 1950;Heath, 1954;Prichep and John, 1992;Pascual-Marqui et al, 1999;Sponheim et al, 2000), positron emission tomographic (PET) (Buchsbaum et al, 2002;Hazlett et al, 1999), histological (Bogerts, 1984;Shenton et al, 2001) and radiological (Shenton et al, 2001) studies indicate spiking activities, increased low frequencies, hypometabolism as well as histopathological and magnetic resonance imaging (MRI) changes in these domains. Indeed, electroencephalographic (EEG) (Spiegel and Wycis, 1950;Heath, 1954;Prichep and John, 1992;Pascual-Marqui et al, 1999;Sponheim et al, 2000), positron emission tomographic (PET) (Buchsbaum et al, 2002;Hazlett et al, 1999), histological (Bogerts, 1984;Shenton et al, 2001) and radiological (Shenton et al, 2001) studies indicate spiking activities, increased low frequencies, hypometabolism as well as histopathological and magnetic resonance imaging (MRI) changes in these domains.…”

Section: Introductionmentioning

confidence: 99%

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Neuropsychiatric thalamocortical dysrhythmia: surgical implications

Jeanmonod

Schulman

Ramírez

et al. 2003

THL

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Neuropsychiatric surgery has had a long and complex history with examples of less than optimal surgical procedures implemented in wrong settings. Such past errors have raised important philosophical and ethical issues that remain with us for good reasons. However, the existence of enormous suffering due to chronic therapy-resistant disabling neuropsychiatric disorders compels a search for alternative surgical approaches based on a sound understanding of the underlying physiopathological mechanisms. We bring evidence, from single cell physiology and magnetoencephalography, for the existence of a set of neuropsychiatric disorders characterized by localized and protracted low frequency spontaneous recurrent activation of the thalamocortical system. This condition, labeled thalamocortical dysrhythmia, underlies certain chronic psychotic, affective, obsessive compulsive, anxiety and impulse control disorders. Considering the central role of recurrent oscillatory thalamocortical properties in the generation of normal hemispheric functions, we propose a surgical approach that provides a reestablishment of normal thalamocortical oscillations without reduction of cortical tissue and its specific thalamic connectivity. It consists of small strategically placed pallidal and medial thalamic lesions that serve to make subcritical the increased low frequency thalamocortical recurrent network activity. This result is attained via reduction of both thalamic overinhibition and low frequency oversynchronization. Thalamic disinhibition is obtained by a lesion in the anterior medial paralimbic pallidum. The medial thalamic lesion is localized in the posterior part of the central lateral nucleus, where a large majority of cells have been shown to be locked in low frequency production and to have lost their normal activation patterns. We present here our experience with 11 patients, including clinical follow ups and pre-and postsurgical magnetoencephalographic studies. The evidence speaks (1) for a benign and efficient surgical approach, and (2) for the relevance of the patient's presurgical cognitive and social settings, making them more or less prone to postoperative psychoreactive manifestations upon rekindling of personal goals and social reentry.

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Section: The Neuropsychiatric Thalamocortical Dysrhythmiamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Neuropsychiatric thalamocortical dysrhythmia: surgical implications

Jeanmonod

Schulman

Ramírez

et al. 2003

THL

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“…[7][8][9] Several investigators have reported that evidence of subcortical spike activity could be detected in the coincident spike-free scalp EEG by using specially designed filtering or discriminate analysis programs.9 10 Methods employed by these investigators depended on use of chronic intracerebral electrodes. Because it is rarely possible to record the EEG from indwelling electrodes in schizophrenic subjects, we have attempted to develop non-invasive methods, previously used to detect evidence of subcortical spike activity in the spike-free scalp EEG of patients with epilepsy, to detect and characterise EEG correlates of schizophrenic behaviours.…”

mentioning

confidence: 99%

Telemetered EEG in schizophrenia: spectral analysis during abnormal behaviour episodes.

Stevens¹,

Livermore²

1982

Journal of Neurology, Neurosurgery & Psychiatry

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SUMMARY In an attempt to detectelectroencephalographic(EEG)changes associated with characteristic clinical signs and symptoms of schizophrenia, power spectra were derived from scalp EEGs of schizophrenic patients recorded by telemetry during free behaviour on their psychiatric wards. Power spectra from EEG epochs coincident with psychomotor blocking, stereotyped automatism or hallucinations were compared with spectra derived during periods of relatively normal behaviour, during performance of specific tasks, and with spectra from control subjects. Ramp spectra, characterised by a smooth decline in power from lowest to highest frequencies, previously found in conjunction with subcortical spike activity of epilepsy were not found in any control subject, but appeared in spectra from schizophrenic patients during catatonic episodes, hallucinatory periods and visual checking.Schizophrenicpatientsalsohad more slow activity and less alpha activity in their EEGs than normal control subjects.A number of similarities between the subjective experiences and stereotyped behaviours of patients with schizophrenia and psychomotor epilepsy suggest that both disorders may reflect abnormal function in limbic structures of the brain. depended on use of chronic intracerebral electrodes. Because it is rarely possible to record the EEG from indwelling electrodes in schizophrenic subjects, we have attempted to develop non-invasive methods, previously used to detect evidence of subcortical spike activity in the spike-free scalp EEG of patients with epilepsy, to detect and characterise EEG correlates of schizophrenic behaviours. In previous studies using chronic implanted intracerebral electrodes in the study of epileptic foci in animals and man, we found that power spectra averaged from brief epochs of spike-free scalp or dural EEG coincident with subcortical spike activity were characterised by a typical profile which we designated a ramp pattern, manifest by a monotonic decline in power from lowest to highest frequency.1' The log graph of this decline approximates an exponential function. Power spectra from two-second epochs of spike-free scalp EEG of patients with epilepsy tested with a continuous performance task revealed a similar ramp pattern over the site of the epileptic focus during prolonged reaction times. When patients with schizophrenia were tested with the continuous performance task, spectral analysis of EEG epochs during prolonged reaction time revealed ramp patterns from one or more scalp montages in six of 17 patients, and ten patients showed "flat" power spectra, that is a relatively even dispersion of power 385 by copyright.

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“…Similarly, a relationship between schizophrenialike psychosis and epilepsy has been suggested by many researchers [55]. The automatisms and high prevalence of sphenoidal spike activity in this schizophrenic-like psychosis of epilepsy suggested involvement of medial temporal lobe structures [56]. Neuropathological investigations of resected temporal lobes from complex partial seizure patients have shown a wide variety of pathological changes.…”

Section: Pathological Correlationsmentioning

confidence: 96%

The Role of the Entorhinal Cortex in Paraphrenia

Casanova

2010

Curr Psychiatry Rep

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Evidence derived from postmortem brain studies has implicated the uncal cortex in paraphrenia. In the present review, we expand on the anatomic and physiologic nuances endogenous to this region that make entorhinal cortex pathology an important clinicopathological correlate to paraphrenia. First, we summarize the anatomic landmarks and histologic features that will allow the reader to define the entorhinal region in future research studies. As cortical regions usually project to neighboring cortices, inferences will be drawn as to the function of the entorhinal region based on the surrounding cortical regions. The results will help explain why patients with paraphrenia may exhibit amnestic deficits that stand in contrast to a well-preserved thought process and personality. We also review the results of surgical ablation studies in animals. These studies suggest that some risk factors currently associated with paraphrenia (eg, social isolation) may in reality be an early manifestation of entorhinal pathology. Finally, the author provides a parallelism between the hallucinations observed in some paraphrenic patients and the results of electrical stimulation of the uncal cortex. The results will help explain why hallucinations in paraphrenia are usually limited to the patient's surroundings.

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Studies in Schizophrenia

Cited by 201 publications

References 0 publications

Neuropsychiatric thalamocortical dysrhythmia: surgical implications

Neuropsychiatric thalamocortical dysrhythmia: surgical implications

Telemetered EEG in schizophrenia: spectral analysis during abnormal behaviour episodes.

The Role of the Entorhinal Cortex in Paraphrenia

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