ELECTRO-ENCEPHALOGRAPHIC STUDIES OF PSYCHOPATHIC PERSONALITIES

The effect of HD-tDCS on brain oscillations and frontal synchronicity during resting-state EEG in violent offenders with a substance dependence

Violence is a major problem in our society and therefore research into the neural underpinnings of aggression has grown exponentially. Although in the past decade the biological underpinnings of aggressive behavior have been examined, research on neural oscillations in violent offenders during resting-state electroencephalography (rsEEG) remains scarce. In this study we aimed to investigate the effect of high-definition transcranial direct current stimulation (HD-tDCS) on frontal theta, alpha and beta frequency power, asymmetrical frontal activity, and frontal synchronicity in violent offenders. Fifty male violent forensic patients diagnosed with a substance dependence were included in a double-blind sham-controlled randomized study. The patients received 20 minutes of HD-tDCS two times a day on five consecutive days. Before and after the intervention, the patients underwent a rsEEG task. Results showed no effect of HD-tDCS on the power in the different frequency bands. Also, no increase in asymmetrical activity was found. However, we found increased synchronicity in frontal regions in the alpha and beta frequency bands indicating enhanced connectivity in frontal brain regions as a result of the HD-tDCS-intervention. This study has enhanced our understanding of the neural underpinnings of aggression and violence, pointing to the importance of alpha and beta frequency bands and their connectivity in frontal brain regions. Although future studies should further investigate the complex neural underpinnings of aggression in different populations and using whole-brain connectivity, it can be suggested with caution, that HD-tDCS could be an innovative method to regain frontal synchronicity in neurorehabilitation.

The forsaking of the clinical EEG by psychiatry: how justified?

Despite decades of publications attesting to the role of the clinical EEG in diagnosing and managing psychiatric disorders, the procedure remains highly underutilized in the practice of psychiatry. The visually inspected EEG (vEEG) can detect various forms of abnormalities, each with its own clinical significance. Abnormalities can be paroxysmal (i.e., suggestive of an epileptic-like process) or stationary. The most important unanswered question remains the value of detecting epileptiform activity in a nonepileptic psychiatric patient in predicting favorable responses to anticonvulsant treatment. Despite the many shortcomings of vEEG, the available evidence suggests that in the presence of paroxysmal activity in a nonepileptic psychiatric patient a trial of a psychotropic anticonvulsant may be warranted if standard treatment has failed. More research on the contribution of paroxysmal EEG abnormalities to the problem of episodic psychiatric symptoms (e.g., panic attacks, dissociative episodes, repeated violence) is sorely needed. It is postulated that at least some of these conditions may represent an epilepsy spectrum disorder. Similarly, the significance of the presence of a slow-wave activity (whether focal or generalized) also deserves further well-designed research to ascertain the exact clinical significance. Nonetheless, the available data suggest that further medical workup is necessary to ascertain the nature and degree of the pathology when present.

The Electroencephalogram, Obsessional Illness and Obsessional Personality

A clinical relationship between obsessional illness and epilepsy is unusual, but the few electroencephalographic (EEG) investigations of obsessional patients which have been published claim a high incidence of abnormal electrical activity. Records of twenty-six neurotic and five schizophrenic patients, all with obsessional symptoms, were examined by Pacellaet al.(13), who found twenty-two of the thirty-one EEGs to be abnormal. Fourteen showed definite convulsive patterns with frequent 2–4 c.p.s. activity and increased high voltage waves after overbreathing. Rockwell and Simons (14) found only two abnormal records in eleven uncomplicated obsessional neurotics, using Gibb's criteria of normality, but of ten patients classified as psychopathic personalities with obsessional symptoms, all had abnormal EEGs although two were borderline. Their definition of psychopathic personality is not made explicit and the clinical distinction between their two groups is unclear. Jarvie (4) reports a case in which slow activity on hyperventilation in the EEG was associated with phobias and obsessional impulses preceded by a two-year history of episodes of rage.

100 admissions to a psychopathic unit

This paper reports the work of a clinical team on 100 consecutive first admissions to a unit constructed for the treatment of psychopaths at Balderton Hospital, Newark, Notts, and opened 1958–61. To prevent bias all male admission with behaviour disorder admitted between 1958–60 are here reported except: five admitted for observation of less than a week, twenty-two admitted only for remand, and those with a Wechsler or Stanford Binet I.Q. less than 56. The unit specialized in delinquents with mental disorder, and received admissions from all over Britain.

The Impulsive Psychopath: A Clinical and Electro-Physiological Study

This paper should be considered a preliminary communication, tentative and suggestive. It is based on a psychiatric and electro-physiological study of 70 cases (children, adolescents and adults) referred for anti-social and/or criminal behaviour, and is an attempt to suggest more defined criteria for the assessment of a particular syndrome.

Electro-Encephalography

The history of electro-encephalography contains both triumphs and disappointments. The most profound of the disappointments is the relative failure to elucidate any of the important problems which concern the psychiatrist. It was hoped that some real electro-physiological alteration would be seen in patients whose mental condition suggested something bordering on the organic, but the negative findings even in the most profound mental disorders are almost as striking as if they were positive. Before considering the published work it would be well to review in a few words the nature and significance of electro-encephalographic records.

Drug Addiction and Habit Formation—An Attempted Integration

In view of the promise attached to the recent attempts to integrate learning and personality theory (Eysenck, 1957), and the suggestion that drug addiction might be a learned response, it would appear profitable to consider the relevance of this integration to a better understanding of addiction, a suggestion reinforced by two recent papers by Partridge (1959a, b). On the basis of a clinical survey of addiction he came to the conclusion that the extent and severity of addiction was dependent on “… the extent to which the particular personality can tolerate them (i.e. the symptoms, such as anxiety, which would arise without the drug) … patients with a low tolerance of discomforts and frustrations are those more likely to be addicts, just as they are more likely to turn to drugs in the first place … the development of addiction, in fact, depends much on the personality … the form of addiction depends more on the circumstances and opportunities with which the particular personality has been confronted.” Such considerations and conclusions can be conceptualized within and predicted from the theoretical framework to be proposed later in the present review.

Epilepsy and Behaviour Disorder in Schoolchildren

In approaching a survey such as this, one is immediately faced not only by the obvious difficulties in a study of a broad cross-section of the population with many divergencies and categories in the hands of so many different physicians and observers, but also, as Gibbs and Stamps (1958) point out, by the fact that “new information has developed so rapidly in the last few years that no time has been allowed for dead opinions to be given a decent burial”.

Genetics in Psychiatry

Workers in psychiatric genetics are, with some notable exceptions, psychiatrists first and geneticists second. Neither their medical nor their psychiatric training equips them with an appreciation of scientific method, and their narrow specialization prevents them from keeping abreast of advances in the general field of animal genetics. As things are, this is an important source of weakness; for the general geneticist, whose science is in a much more advanced state, has accumulated facts and theories that have an immediate application in our special field. One has therefore to notice comprehensive reviews of the present position in genetics in relation to the theory of evolution which have recently been provided by Dobzhansky (1941) and Huxley (1942). In what follows the work of Huxley has chiefly been drawn upon, and it is intended to provide a brief summary of the most important of these ideas.

Psychopathic Personality

The discussion of any topic is handicapped so long as there are doubts and disagreement as to what is being discussed.

Epilepsy spectrum disorders: A concept in need of validation or refutation

Episodic psychiatric symptoms are not uncommon and range from panic attacks to repeated violent acts. Some evidence has accumulated over the years that at least in a subset of patients exhibiting these symptoms there may be evidence for the presence of focal cortical/subcortical hyperexcitability. In these cases the condition could be conceptualized as an epilepsy spectrum disorder (ESD) with significant treatment implications. There is currently no clear demarcation of this category of symptoms, their prevalence, an understanding of how these symptoms occur, what is appropriate work up and possible treatments. In this article, we propose that milder degrees of increased neural excitability (i.e., a subthreshold excitation insufficient to cause seizures) may nonetheless be capable of causing observable phenotypic changes. The observable phenotypic changes depend on the degree of hyperexcitability and the location of the hyperexcitable neural tissue. The location of the abnormal neural tissue may dictate the initial manifestation of an attack resulting from activation of the hyperexcitable tissue, but the anatomical connectivity of the abnormal region will dictate the breadth of manifestations. We provide some evidence, derived mainly from either electroencephalography studies of these populations or clinical reports of response to anti-epilepsy treatment, for the assumption and propose methods to test the advanced hypothesis.

The sociopathy of sociobiology

Mealey's evolutionary reasoning is logically flawed. Furthermore, the evidence presented in favor of a genetic contribution to the causation of sociopathy is overinterpreted. Given the potentially large societal impact of sociobiological speculation on the roots of criminality, more-than-usual caution in interpreting data is called for.

Prisoner's Dilemma, Chicken, and mixedstrategy evolutionary equilibria

Mealey's interesting interpretation of sociopathy is based on an inappropriate two-person game model. A multiperson, compound game version of Chicken would be more suitable, because a population engaging in random pairwise interactions with that structure would evolve to an equilibrium in which a fixed proportion of strategic choices was exploitative, antisocial, and risky, as required by Mealey's interpretation.

"All that spikes is not fits", mistaking the woods for the trees: the interictal spikes--an "EEG chameleon" in the interface disorders of brain and mind: a critical review

Recent research into mammalian cortical neurophysiology, after 6 decades of Berger's seminal work on electroencephalography, has shifted the older concept of interictal epileptiform activity (IEA) away from that of a mere electrographic graphoelement of relevance to diagnostic implications in epilepsy. Instead, accumulating information has stressed the neuropsychological implications, cognitive and/or behavioral consequence of these electrophysiological events, which are the phenotypic expression of aberrations of actual biophysical cellular function. We feel that this review is germane to neuropsychiatry, however, a rather neglected area of research. There is a great scope for brain-behavior-EEG research in the future that can be complimented by other techniques of "neurobehavioral electrophysiology". This review does not address the "pearls, perils and pitfalls" in the use of EEG in epilepsy, but critically and systematically reappraises the published electroencephalographic correlates of human behavior. We reiterate that epileptiform and other paroxysmal EEG dysrhythmias unrelated to clinical seizures do have neuropsychological, cognitive and/or behavioral implications as seen in the various neuropsychiatric and neurobehavioral disorders discussed in this article. IEA and EEG dysrhythmias should neither be ignored as irrelevant nor automatically attributed to epilepsy. The relevance of these EEG aberrations in the disorders of the brain-mind interface extend beyond epilepsy, and may be an electrophysiological endophenotype of aberrant neuronal behavior indicative of underlying morpho-functional brain abnormalities. Magnetoencephalography (MEG), data fusion models (EEG-fMRI-BOLD), transcranial magnetic stimulation (TMS), evoked potentials (EP); intracranial electrophysiology, and EEG neurofeedback complemented by current functional neuroimaging techniques (fMRI and PET) would certainly help in further understanding the broader relationship between brain and behavior.

An animal model to study the clinical significance of interictal spiking

Interictal spikes (IIS) are paroxysmal discharges commonly observed in patients with epilepsy which represent an abnormally-synchronized population of hyperexcitable neurons firing as an aggregate. Due to conflicting studies on the clinical significance of IIS, research focusing on IIS has been sparse. However, recent attention on IIS has increased for patients undergoing surgery for intractable epilepsy as a means to identify epileptic foci for surgical resection. There is growing evidence that IIS are not asymptomatic as has been commonly accepted. Other than epilepsy, IIS have been associated with a wide range of behavioral and psychiatric disorders, including attention deficit disorder, anxiety disorders and psychoses. For these reasons, a well-characterized animal model of interictal spiking which accurately mimics the human phenomenon would be a valuable tool to gain, insights both into the pathophysiology of epilepsy as well as a broad variety of human neuropsychiatric diseases. Here, we review the literature on the clinical significance of IIS in humans and on animal models where IIS has been observed. We then demonstrate the utility of using tetanus toxin to generate a reproducible pattem of progressive IIS for future studies into their clinical significance.

Quantitative electroencephalographic measures in homicidal men with antisocial personality disorder

Many symptoms of antisocial personality disorder have been proposed to be related to decreased daytime vigilance. To explore this hypothesis, quantitative analyses were conducted of the electroencephalographic (EEG) activity of drug-free and detoxified homicidal male offenders with antisocial personality disorder as the primary diagnosis. Subjects comprised 16 men recruited from a forensic psychiatric examination in a special ward of a university psychiatric hospital. Fifteen healthy age- and gender-matched controls with no criminal record or history of physical violence consisted of hospital staff and students. An overall reduction of alpha power was observed in the waking EEG of offenders. A bilateral increase in occipital delta and theta power was also found in these individuals. This study provides further support to the growing evidence of brain dysfunction in severe aggressive behavior. Homicidal offenders with antisocial personality disorder seem to have difficulties in maintaining normal daytime arousal. Decreased vigilance, together with social and psychological variables, may explain their aberrant behavior in everyday life. New studies are, however, needed to specify the vigilance problems of this patient group.

Fatherless rearing leads to sociopathy

Endorsing Mealey's analysis, it is pointed out that increasing rates of crime and violence are due to increasing proportions of children being reared in circumstances radically different from the extendedfamily environment to which we are evolntionarily adapted, that is, they are reared without fathers.

Sociopathy and sociobiology: Biological units and behavioral units

Behavioral biologists have long sought to link behavioral units (e.g., aggression, depression, sociopathy) with biological units (e.g., genes, neurotransmitters, hormones, neuroanatomical loci). These units, originally contrived for descriptive purposes, often lead to misunderstandings when they are reified for purposes of causal analysis. This genetic and biochemical explanation for sociopathy reflects such problems.

Is sociopathy a type or not? Will the “real” sociopathy please stand up?

The validity of the classification of “primary sociopaths” as a qualitatively distinct group in the general population is questioned. Cenetic variation in the experience and expression of emotions may play a role in the development of antisocial behavior. However, research clearly documents that socialization environments powerfully modify the expression of genetic biases in a manner that increases or decreases the risk for “sociopathy.”