Akira Sengoku

Frontal midline theta rhythm is correlated with cardiac autonomic activities during the performance of an attention demanding meditation procedure

Frontal midline theta rhythm (Fm theta), recognized as distinct theta activity on EEG in the frontal midline area, reflects mental concentration as well as meditative state or relief from anxiety. Attentional network in anterior frontal lobes including anterior cingulate cortex is suspected to be the generator of this activity, and the regulative function of the frontal neural network over autonomic nervous system (ANS) during cognitive process is suggested. However no studies have examined peripheral autonomic activities during Fm theta induction, and interaction of central and peripheral mechanism associated with Fm theta remains unclear. In the present study, a standard procedure of Zen meditation requiring sustained attention and breath control was employed as the task to provoke Fm theta, and simultaneous EEG and ECG recordings were performed. For the subjects in which Fm theta activities were provoked (six men, six women, 48% of the total subjects), peripheral autonomic activities were evaluated during the appearance of Fm theta as well as during control periods. Successive inter-beat intervals were measured from the ECG, and a recently developed method of analysis by Toichi et al. (J. Auton. Nerv. Syst. 62 (1997) 79-84) based on heart rate variability was used to assess cardiac sympathetic and parasympathetic functions separately. Both sympathetic and parasympathetic indices were increased during the appearance of Fm theta compared with control periods. Theta band activities in the frontal area were correlated negatively with sympathetic activation. The results suggest a close relationship between cardiac autonomic function and activity of medial frontal neural circuitry.

A new method of assessing cardiac autonomic function and its comparison with spectral analysis and coefficient of variation of R–R interval

A new non-linear method of assessing cardiac autonomic function was examined in a pharmacological experiment in ten healthy volunteers. The R-R interval data obtained under a control condition and in autonomic blockade by atropine and by propranolol were analyzed by each of the new methods employing Lorenz plot, spectral analysis and the coefficient of variation. With our method we derived two measures, the cardiac vagal index and the cardiac sympathetic index, which indicate vagal and sympathetic function separately. These two indices were found to be more reliable than those obtained by the other two methods. We anticipate that the non-invasive assessment of short-term cardiac autonomic function will come to be performed more reliably and conveniently by this method.

The influence of psychotic states on the autonomic nervous system in schizophrenia

Abnormal autonomic activity in patients with schizophrenia has been reported, but how psychotic states influence the autonomic nervous system (ANS) has remained unclear due to methodological limitations. The influence of psychotic states on ANS activity in patients with schizophrenia was investigated using a recently developed method of analysis based on heart rate variability which assesses cardiac sympathetic and parasympathetic function separately. Cardiac autonomic function (CAF), together with psychotic states, was assessed at the beginning and the end of an 8-week study period in 53 patients with chronic schizophrenia. The CAF in age- and sex-matched control subjects was also examined. There were no significant differences between the patients and the control subjects in the mean R-R interval (RRI) or in the indices of the sympathetic and the parasympathetic function. In the patients who changed in psychotic states, the parasympathetic index was significantly decreased without significant changes in the sympathetic index when their psychotic states were more pronounced, suggesting psychotic states suppressed the parasympathetic function without affecting the sympathetic function. In these patients, the mean RRI was smaller when their psychotic states were more pronounced. Our results demonstrate that psychotic states affect the ANS, suggesting a relationship between cerebral cognitive and peripheral ANS activities, and that this is presumably mediated through the parasympathetic nervous system. These findings are discussed in comparison with previous reports on the CAF in schizophrenia.

Seeing Happy Emotion in Fearful and Angry Faces: Qualitative Analysis of Facial Expression Recognition in a Bilateral Amygdala-Damaged Patient

Neuropsychological studies reported that bilateral amygdala-damaged patients had impaired recognition of facial expressions of fear. However, the specificity of this impairment remains unclear. To address this issue, we carried out two experiments concerning the recognition of facial expression in a patient with bilateral amygdala damage (HY). In Experiment 1, subjects matched the emotion of facial expressions with appropriate verbal labels, using standardized photographs of facial expressions illustrating six basic emotions. The performance of HY was compared with age-matched normal controls (n = 13) and brain-damaged controls (n = 9). HY was less able to recognize facial expressions showing fear than normal controls. In addition, the error pattern exhibited by HY for facial expressions of fear and anger were distinct from those exhibited by both control groups, and suggested that HY confused these emotions with happiness. In Experiment 2, subjects were presented with morphed facial expressions that blended happiness and fear, happiness and anger, or happiness and sadness. Subjects were requested to categorize these expressions by two-way forced-choice selection. The performance of HY was compared with age-matched normal controls (n = 8). HY categorized the morphed fearful and angry expressions blended with some happy content as happy facial expressions more frequently than normal controls. These findings support the idea that amygdala-damaged patients have impaired processing of facial expressions relating to certain negative emotions, particularly fear and anger. More specifically, amygdala-damaged patients seem to give positively biased evaluations for these negative facial expressions.

Interictal change in cardiac autonomic function associated with EEG abnormalities and clinical symptoms : A longitudinal study following acute deterioration in two patients with temporal lobe epilepsy

The purpose of the present study was to investigate the ictal and interictal changes in cardiac autonomic function (CAF), and the relationship between the interictal change in CAF to the electroencephalogram (EEG) and clinical findings. In two patients with temporal lobe epilepsy (TLE) showing acute deterioration, a quantitative evaluation of their interictal CAF based on heart rate variability and their EEG using spectral analysis was conducted, and the findings compared with repeated clinical evaluations during the recovery period. The ictal heart rate changes and their temporal relationship to ictal discharge were investigated using simultaneous EEG/electrocardiogram (ECG) monitoring in one of the patients. Interictal parasympathetic function was decreased during the period of acute deterioration, but was increased in association with improvements in the EEG and clinical findings. In contrast, the sympathetic function showed no specific changes. The ictal discharges were preceded by a brief bradycardia, with a long delay of up to 40 s. The results demonstrated that this decrease in parasympathetic function was closely related to the interictal changes in central nervous system function. On the other hand, the ictal discharges in one of the patients were thought to have caused a transient elevation of parasympathetic function. It is strongly suggested that patients with TLE have interictal as well as ictal changes in CAF that are mediated mainly through the parasympathetic nervous system.

Risks of occurrence of psychoses in relation to the types of epilepsies and epileptic seizures.

Abstract: The possible existence of the risks of occurrence of psychoses was examined in relation to the types of epilepsies and epileptic seizures. This study consisted of two investigations: 1) A study of 879 epileptic patients was conducted in which the incidence of psychoses in the different types of epilepsies was surveyed; the result was that the incidence in temporal lobe epilepsy was the highest, being relatively higher than that of other (non‐temporal lobe) partial epilepsies but not significantly different from that of generalized epilepsies. 2) A comparative study was carried out on 96 patients with temporal lobe epilepsy in which 48 were psychotic and another 48 were non‐psychotic which served as a control group. The differences of seizure symptomatology between the two groups were compared. The results were that the psychotic group was found to exhibit at a significantly higher rate generalized tonic‐clonic convulsion and compound seizure manifestations in comparison with the non‐psychotic group. The results appear to support the fact that generalizing mechanisms of temporal lobe epileptic manifestations are closely related to a physiopathogenic factor influencing psychoses.

Unknown People Believed to Be Known: The ‘assoziierende Erinnerungs- fälschungen’ by Kraepelin

A male patient with epilepsy, who developed a unique form of paramnesia after an episode of zonisamide-induced psychosis is reported. The patient consistently mistook people who were quite new to him, such as staff of the hospital, for persons whom he had met long ago. However, he did not misidentify their names or other attributes, such as their occupations. This extraordinary form of misidentification does not fall into any known subcategory of misidentification syndromes. Rather, this paramnesia falls into the classical description of ‘assoziierende Erinnerungsfälschungen’ by Kraepelin. The neuropsychological interpretation of the reported patient is difficult. However, loss of familiarity with environmental objects due to his long sustained epileptic history is supposed to be a possible mechanism of paramnesia.

Comparison of Psychotic States in Patients with Idiopathic Generalized Epilepsy and Temporal Lobe Epilepsy

Summary: We compared the characteristics of psychotic symptoms and pathogeneses of psychotic states in patients with idiopathic generalized epilepsy (IGE) and temporal lobe epilepsy (TLE). Sixty‐seven patients with IGE and 105 patients with TLE who were treated in our psychiatric clinic between December 1991 and July 1996 were selected. The clinical characteristics of the psychotic states accompanying each type of epilepsy were investigated retrospectively. Psychotic states were ascertained in 19.4% of the patients with IGE and 15.2% of the patients with TLE. The psychotic states of the patients with TLE tended to be more chronic than those of the patients with IGE. The characteristic psychotic symptoms were perplexed behavior and other various psychotic symptoms in the IGE group and hallucinations, delusions, and bad temper in the TLE group. The correlation with seizures was more evident in the TLE group than in the IGE group, because the seizure frequencies before the onset of psychotic states were significantly higher in the TLE group. The relationship between epileptic discharges and psychotic state was significantly more distinct in the IGE group. However, 3 patients with TLE with episodic psychotic states were mentally improved after tem‐prod lobectomy, which suggested that deep midtemporal epileptic discharges might have been the cause of their psychotic states. The psychotic symptoms of the patients with IGE and those with TLE were clearly different, and the incessant epileptic discharges of the different cerebral regions might be a key factor in the psychotic states accompanying both types of epilepsy.

Dreamy states and psychoses in temporal lobe epilepsy: Mediating role of affect

Abstract Among 104 patients with temporal lobe epilepsy treated in our clinic between 1992–1995, thirteen patients with repeated dreamy states were evaluated for affective manifestations of dreamy states and their relationship with psychotic states. The types of dreamy states were classified as déjà vu, jamais vu and reminiscence. The affective experiences during dreamy states were evaluated as positive, negative or neutral. As a result, seven patients had déjà vu and/or reminiscence: seizure manifestations in four of these patients were affectively evaluated as positive (familiar and/or pleasurable), and three as neutral. Six cases had experience of jamais vu: five of them were affectively evaluated as negative (mostly fear), and one as neutral.

The Contribution of J. H. Jackson to Present-Day Epileptology

Summary: Contributions made by John Hughlings Jackson (1835–1911) to todays epileptology are unparalleled, and what he did has still not been reevaluated. We divide his contributions into three themes: (a) He began his research with the seizures later named jacksonian seizures. Through his research, Jackson established a revolutionary definition quite similar to our contemporary definition of epilepsy. The first step was made to the neurosurgical treatment for epilepsy through his research. (b) He elucidated the mechanism of postepileptic psychosis by his theory of evolution–dissolution and positive–negative symptoms, later called jacksonism. (c) His encounter with his patient, Dr. Z, helped him to establish his idea of dreamy state, eventually leading to the concept of temporal lobe epilepsy.