Laterlization of conversion symptoms: more frequent on the left

A lateralized model of the pain-depression dyad

Chronic pain and depression are two frequently co-occurring and debilitating conditions. Even though the former is treated as a physical affliction, and the latter as a mental illness, both disorders closely share neural substrates. Here, we review the association of pain with depression, especially when symptoms are lateralized on either side of the body. We also explore the overlapping regions in the forebrain implicated in these conditions. Finally, we synthesize these findings into a model, which addresses gaps in our understanding of comorbid pain and depression. Our lateralized pain-depression dyad model suggests that individuals diagnosed with depression should be closely monitored for pain symptoms in the left hemibody. Conversely, for patients in pain, with the exception of acute pain with a known source, referrals in today's pain centers for psychological evaluation should be part of standard practice, within the framework of an interdisciplinary approach to pain treatment.

Dichotic Listening in Relation to Dysphoria, Sensation Seeking, and other Personality Characteristics

According to a 1983 model proposed by Levy, anxiety, dysphoria, and a critical attitude are associated with greater left- than right-hemisphere activity, while optimism and uncritical evaluations correlate with stronger right- than left-hemisphere activity. A dichotic-listening task and a set of personality questionnaires were administered to 150 students in psychology. The personality measures included Dutch versions of the Beck Depression Inventory, the Zung Self-rating Depression Scale, the Sensation-seeking Scale V and a brief MMPI. Correlations between the extent of left-hemisphere reliance as measured by a right-ear advantage score on the dichotic-listening task and the various personality measures were computed, forming a test of some aspects of Levy's (1983) model. If performance on a dichotic-listening task reflects hemispheric reliance then we found little evidence, on the whole, to support Levy's model.

Prevalence and distribution of MRI abnormalities in patients with psychogenic nonepileptic events

INTRODUCTION

Both structural and functional abnormalities have been reported in patients with psychogenic nonepileptic events (PNEEs), although no truly consistent abnormalities have been found.

METHODS

We retrospectively identified patients discharged from our EMU with video-EEG diagnoses of epileptic seizures, PNEEs, epileptic seizures plus PNEEs, interictal epileptiform abnormalities only, and nondiagnostic admissions. We then collected brain MRI results for analysis.

RESULTS

We found significant brain MRI abnormalities in 33.8% of patients with PNEEs, clearly higher than the rate of brain MRI abnormalities in the healthy population. In addition, we found statistically significant differences in the locations of brain MRI abnormalities in patients with epileptic seizures (more frequently temporal) versus PNEEs (more frequently multifocal).

CONCLUSION

This multifocal nature of abnormalities in patients with psychogenic nonepileptic events may help to explain the underlying pathophysiology as it relates to psychiatric disorders which are so frequently comorbid with PNEEs.

Lateralized, nonepileptic convulsions in an adult with cerebral palsy: Case report and review of the literature

The authors report a case of unilateral functional neurological symptoms (nonepileptic convulsions) in a 38-year-old man with mild, motor-predominant cerebral palsy. His convulsions are all lateralized to the same side as his paretic limbs. His episodes significantly decreased after several months of weekly psychodynamic-oriented psychotherapy. Functional neurological disorders have been rarely reported in children or adults with cerebral palsy. Among patients with brain injury, right-hemispheric brain disease may be more helpful than either handedness or the side of symptoms in clinically profiling patients with suspected functional disorders. This case raises biomechanistic questions about brain injury, the development of functional disorders, and the lateralization of functional symptoms.

Brain circuits implicated in psychogenic paralysis in conversion disorders and hypnosis

Conversion disorders are defined as neurological symptoms arising without organic damage to the nervous system, presumably in relation to various emotional stress factors, but the exact neural substrates of these symptoms and the mechanisms responsible for their production remain poorly understood. In the past 15 years, novel insights have been gained with the advent of functional neuroimaging studies in patients suffering from conversion disorders in both motor and non-motor (e.g. somatosensory, visual) domains. Several studies have also compared brain activation patterns in conversion to those observed during hypnosis, where similar functional losses can be evoked by suggestion. The current review summarizes these recent results and the main neurobiological hypotheses proposed to account for conversion symptoms, in particular motor deficits. An emerging model points to an important role of ventromedial prefrontal cortex (VMPFC), precuneus, and perhaps other limbic structures (including amygdala), all frequently found to be hyperactivated in conversion disorders in parallel to impaired recruitment of primary motor and/or sensory pathways at the cortical or subcortical (basal ganglia) level. These findings are only partly shared with hypnosis, where increases in precuneus predominate, together with activation of attentional control systems, but without any activation of VMPFC. Both VMPFC and precuneus are key regions for access to internal representations about the self, integrating information from memory and imagery with affective relevance (in VMPFC) and sensory or agency representations (in precuneus). It is therefore postulated that conversion deficits might result from an alteration of conscious sensorimotor functions and self-awareness under the influence of affective and sensory representations generated in these regions, which might promote certain patterns of behaviors in response to self-relevant emotional states.

[Lateral asymmetry of the human pain sensitivity.]

In repeated clinical studies a preponderance of pain syndromes on the left side of the body has frequently been observed. Experimental studies in humans revealed a lower pain threshold on the left, nondominant side. On the other hand, some studies do not confirm this lateralization. Since pain threshold is not a very valid measure of pain sensitivity in the range beyond threshold, and since clinical studies are limited by simply counting the incidence of the pain syndromes, we investigated whether a significant lateralization of pain sensitivity exists in the entire range beyond pain threshold. Handedness and gender were included as factors. For experimental pain stimulation in 24 subjects three different methods were used: local pressure on the middle phalanxes, a modified submaximal effort tourniquet test, and submerging the hands into cold water. For pain measurement beyond threshold we used the category splitting procedure (Heller).All three methods of stimulation produced corresponding results. Lefthanded subjects showed decreased pain sensitivity on the left side, right-handed subjects on the right side. This was true for the total range of pain sensitivity. For pain induced by pressure, lateral asymmetry increased with pain intensity, for the other two methods it was constant. Lateral asymmetry was found in all subjects, but significant differences could only be demonstrated in female Ss. It is concluded that both gender and handedness contribute to lateral asymmetry of pain sensitivity in man.

Brain dysfunction in fibromyalgia and somatization disorder using proton magnetic resonance spectroscopy: a controlled study

OBJECTIVE

To evaluate the brain metabolite patterns in patients with fibromyalgia (FM) and somatization disorder (STD) compared with healthy controls through spectroscopy techniques and correlate these patterns with psychological variables.

METHOD

Design. Controlled, cross-sectional study. Sample. Patients were recruited from primary care in Zaragoza, Spain. The control group was recruited from hospital staff. Patients were administered questionnaires on pain catastrophizing, anxiety, depression, pain, quality of life, and cognitive impairment. All patients underwent Magnetic Resonance Imaging and magnetic resonance spectroscopy (MRS).

RESULTS

A significant increase was found in the glutamate + glutamine (Glx) levels in the posterior cingulate cortex (PCC): 10.73 (SD: 0.49) for FM and 9.67 (SD: 1.10) for STD 9.54 (SD: 1.46) compared with controls (P = 0.043). In the FM + STD group, a correlation between Glx and pain catastrophizing in PCC (r = 0.397; P = 0.033) and between quality of life and the myo-inositol/creatine ratio in the left hippocampus (r = -0.500; P = 0.025) was found. To conclude Glutamate seems to be relevant in the molecular processes involved in FM and STD. It also opens the door for Proton MRS ((1) H-MRS) in STD and suggests that reducing glutamatergic activity through pharmacological treatment could improve the outcome of patients with FM and STD.

CONCLUSION

Glutamate seems to be relevant in the molecular processes involved in FM and STD. It also opens the door for Proton MRS ((1) H-MRS) in STD and suggests that reducing glutamatergic activity through pharmacological treatment could improve the outcome of patients with FM and STD.

Nineteenth-century ideas on hemisphere differences and “duality of mind”

It is widely felt that the sorts of ideas current in modern laterality and split-brain research are largely without precedent in the behavioral and brain sciences. This paper not only challenges that view, but makes a first attempt to define the relevance of older concepts and data to present research programs.

In the 19th century, there was a body of literature that held that many mental pathologies could be explained by supposing that each individual potentially had two conscious brains. Madness resulted when these begin to interfere with each other or otherwise functioned independently. The left-sided localization of language by Broca in the 1860s complicated matters by showing that the two brain halves functioned differently. Broca argued that functional asymmetry was a reflection of man's capacity to “perfect” himself; soon, the left hemisphere was transformed into the superior, uniquely human side of the brain. Considerable effort then went into seeing how far the functions of the right hemisphere complemented those of the left. The resulting dichotomies of mind and brain interacted—and sometimes also conflicted—with “duality of mind” theories. In the 1880s, the Paris school of neurology helped bring about a revival of interest in these theories with its startling metalloscopy and hemihypnosis experiments.

A section of this target article is devoted to the views of Hughlings Jackson. Jackson's physiological/philosophical writings on hemisphere specialization and mental duality largely set him outside of the rest of the 19th-century tradition. The article concludes that at least some of the data gathered in the 19th century might prove useful or interesting to certain investigators today. More important, it asks how far an awareness of the “time-bound” nature of 19th-century concepts should change the way in which one surveys the laterality scene today.

Streamlined classification of psychopathological hand disorders: A literature review

In the surgical hand clinic, psychopathological hand disorders can be sorted into one of the following four categories: (1) factitious wound creation and manipulation; (2) factitious edema; (3) psychopathological dystonias, and (4) psychopathological sensory abnormalities and psychopathological Complex Regional Pain Syndrome. This article introduces these four categories. Pertinent literature that includes descriptions of each category's syndromes and diseases, demographic and psychological profiles, differential diagnoses, and appropriate treatment recommendations is reviewed.

Does Repression Exist? Memory, Pathogenic, Unconscious and Clinical Evidence

The current dispute regarding the existence of repression has mainly focused on whether people remember or forget trauma. Repression, however, is a multidimensional construct, which, in addition to the memory aspect, consists of pathogenic effects on adjustment and the unconscious. Accordingly, in order to arrive at a more accurate decision regarding the existence of repression, studies relevant to all three areas are reviewed. Moreover, since psychoanalysis regards repression as a key factor in accounting for the development and treatment of neurotic disorders, relevant research from these two domains are also taken into account. This comprehensive evaluation reveals little empirical justification for maintaining the psychoanalytic concept of repression.

Functional magnetic resonance imaging analysis of attention to one's heartbeat

OBJECTIVES

The convergence of a neural system for monitoring external stimuli with mechanisms that process somatic information leads to the hypothesis that the anterior parietal cortex may mediate attention to a specific internal visceral signal.

METHODS

We measured regional brain activity through functional magnetic resonance imaging and directed subjects (6 men and 11 women) to attend to their own heartbeat, and to a heartbeat played on an external tape.

RESULTS

Statistical parametric brain mapping revealed the importance of right (nondominant) parietal cortex to directing attention internally to one's visceral state and focusing on a specific body signal.

CONCLUSIONS

The parietal activation may be taking advantage of monitoring skills typically utilized for vigilance to the external environment, in addition to working as a higher-level recognition system for signals emerging from the viscera. The finding suggests that the parietal cortex plays a central role in an interoceptive attention system that monitors bodily states.

Hysterical conversion and brain function

Hysterical conversion disorders represent "functional" or unexplained neurological deficits such as paralysis or somatosensory losses that are not explained by organic lesions in the nervous system, but arise in the context of "psychogenic" stress or emotional conflicts. After more than a century of both clinical and theoretical interest, the exact nature of such emotional disorders responsible for hysterical symptoms, and their functional consequences on neural systems in the brain, still remain largely unknown. However, several recent studies have used functional brain imaging techniques (such as EEG, fMRI, PET, or SPECT) in the attempt to identify specific neural correlates associated with hysterical conversion symptoms. This article presents a general overview of these findings and of previous neuropsychologically based accounts of hysteria. Functional neuroimaging has revealed selective decreases in the activity of frontal and subcortical circuits involved in motor control during hysterical paralysis, decreases in somatosensory cortices during hysterical anesthesia, or decreases in visual cortex during hysterical blindness. Such changes are usually not accompanied by any significant changes in elementary stages of sensory or motor processing as measured by evoked potentials, although some changes in later stages of integration (such as P300 responses) have been reported. On the other hand, several neuroimaging results have shown increased activation in limbic regions, such as cingulate or orbitofrontal cortex during conversion symptoms affecting different sensory or motor modalities. Taken together, these data generally do not support previous proposals that hysteria might involve an exclusion of sensorimotor representations from awareness through attentional processes. They rather seem to point to a modulation of such representations by primary affective or stress-related factors, perhaps involving primitive reflexive mechanisms of protection and alertness that are partly independent of conscious control, and mediated by dynamic modulatory interactions between limbic and sensorimotor networks. A better understanding of the neuropsychobiological bases of hysterical conversion disorder might therefore be obtained by future imaging studies that compare different conversion symptoms and employ functional connectivity analyses. This should not only lead to improve clinical management of these patients, but also provide new insights on the brain mechanisms of self-awareness.

Somatoform Disorders After Temporal Lobectomy

OBJECTIVE

Depression, anxiety, and psychosis are the most frequent psychiatric disorders after epilepsy surgery. The only new-onset somatoform disorder reported postoperatively is conversion disorder. We identified 10 patients who developed somatoform disorder other than nonconversion epileptic seizures after anterior temporal lobectomy.

METHOD

We retrospectively reviewed the charts of 325 anterior temporal lobectomy and 125 extratemporal surgeries between 1991 and 2000.

RESULTS

Seven of the patients developed undifferentiated somatoform disorder after anterior temporal lobectomy, 1 had pain and body dysmorphia, another had pain disorder, and another had body dysmorphia alone, but none were found after extratemporal surgeries (chi-square = 3.93; P < or = 0.05). Somatoform disorder was significantly more common in right anterior temporal lobectomy (n = 9) than left anterior temporal lobectomy (n = 1) (chi-square = 6.5; P < or = 0.025).

CONCLUSIONS

Our findings suggest that right temporal resection contributes to the development of somatoform disorders in our patients and that right temporal dysfunctions may contribute to idiopathic somatoform disorders.

Evidence of brain abnormality in patients with psychogenic nonepileptic seizures

Markers of brain abnormalities in patients with psychogenic nonepileptic seizures (PNES) were studied to explore whether physical brain disorder is associated with an increased risk of PNES. Evidence of epileptiform EEG changes, MRI abnormalities, and neuropsychological (NPS) deficits was obtained from the records of 329 consecutive patients in whom the diagnosis of PNES was established at our center between 1991 and 2001. Two hundred six patients had PNES alone, and 123 PNES and epilepsy (PNES+E). In the PNES-only group, at least one marker of brain disorder was detected in 22.3% of patients (epileptiform potentials in 8.7%, MRI changes in 9.7%, NPS deficits in 9.7%). The actual prevalence of abnormalities is likely to be higher because 54.9% of the patients with only psychogenic seizures did not undergo MRI or neuropsychological testing. Evidence of brain abnormality was found more frequently in the PNES+E group (epileptiform potentials in 70.7%, MRI changes in 60.2%, NPS deficits in 52.8%). Although markers of brain abnormality were detected much less commonly in the PNES than in the PNES+E group, they were still found in a substantial proportion of patients with PNES alone. This suggests that physical brain disease plays a role in the development of PNES. Markers of physical abnormality were not more common in the right hemisphere.

The question of symptom lateralization in conversion disorder

OBJECTIVE

The purpose of this study was to determine whether or not conversion symptoms are lateralized. Studies have shown a predominant left-oriented manifestation of symptoms for most somatoform disorders. The reports in the literature on the lateralization of conversion symptoms, however, are rather conflicting. They show left-sided, right-sided, or no symptom lateralization in conversion disorders.

METHODS

One hundred fourteen patients with conversion disorder were screened for symptom lateralization.

RESULTS

Those patients with unilateral symptoms (32.5%) showed no significant bias toward left or right symptom presentation.

CONCLUSION

Based on these results, and the conflicting findings from previous studies, we conclude that there is insufficient support for lateralization theories in conversion disorder.

Physiologically initiated and inhibited phantosmia: cyclic unirhinal, episodic, recurrent phantosmia revealed by brain fMRI

PURPOSE

Our goal was to use functional magnetic resonance imaging (fMRI) to demonstrate brain activation in patients with unirhinal, episodic, recurrent phantosmia who induced their phantosmia by coughing, sneezing, laughing or vigorous nasal inhalation and expiration, and inhibited it by sleep or performance of a Valsalva type maneuver.

METHODS

Three patients with unirhinal phantosmia without change in taste or smell acuity were studied by fast low angle shot (FLASH) MRI and by echo planar imaging (EPI). Brain activation was measured following memory of two tastants (salt, sweet), memory of two odorants (banana and peppermint), actual smell of three odors (amyl acetate, menthone, pyridine), memory of phantosmia (and phantageusia, where applicable), phantosmia initiated spontaneously or by vigorous nasal inhalation and exhalation, phantosmia after inhibition by Valsalva, and these stimuli before and after treatment with the neuroleptic thioridazine. Activation images were derived using correlation analysis and ratios of areas of brain activated to total brain areas were calculated. Total activated pixel cluster counts were also used to quantitative total and regional brain activation.

RESULTS

Sensory-specific brain activation was present in each section in each patient following memory of tastants and odorants, actual smell of each odor and memory, and initiation of and inhibition of phantosmia. Activation to odor memory after phantosmia initiation was very robust, whereas after phantosmia inhibition it was similar to that in normal subjects. Brain activation to unirhinal phantosmia was bihemispheric, independent of whether it was left or right sided or patient handedness. While phantosmia memory (in the absence of initiated phantosmia) produced extremely robust brain activation, after initiation and inhibition of phantosmia apparent brain activation decreased. These changes need to be related to shifting state of baseline brain activation and should be interpreted to reflect increased rather than decreased brain activation over that of phantosmia memory alone. Treatment with thioridazine inhibited brain activation to all stimuli including phantosmia and phantageusia memory, as it did previously in patients with birhinal phantosmia.

CONCLUSIONS

1) Unirhinal phantosmia can be demonstrated by brain fMRI as can birhinal phantosmia; 2) unirhinal phantosmia can be initiated and inhibited by physiological maneuvers reflected by changes in fMRI brain activation; 3) fMRI brain activation of unirhinal phantosmia is bihemispheric and independent of peripheral side of phantosmia or patient handedness; 4) anterior frontal brain region plays a significant role in both phantosmia initiation and inhibition as, to some extent, do temporal brain regions; 5) activation of brain GABAergic systems appears to play a role in inhibition of unirhinal phantosmia; and 6) unirhinal phantosmia, similar to birhinal phantosmia, may reflect a type of maladaptive brain plasticity similar to that hypothesized to be responsible for phantom limb pain.

Motor conversion disorder. A prospective 2- to 5-year follow-up study

In this prospective study, 30 patients with motor conversion disorder were assessed for key psychiatric and demographic variables. At reassessment 2 to 5 years later, 19 patients had completely recovered and 8 patients had improved, whereas only 3 were unchanged or worse. Contrary to other follow-up studies, none of the patients received a rediagnosis of neurological disease. The presence of a personality disorder and overall personality pathology, particularly within cluster C, the presence of a concomitant somatic disease, low DSM-IV Axis V score, and high score on the Becks Hopelessness Scale proved to be associated with poor outcome.

Diagnosis and rehabilitation strategies for patients with hysterical hemiparesis: a report of four cases

Conversion disorder is a psychological disturbance that produces subconscious alterations in sensorimotor function. Hysterical hemiparesis is a relatively rare, and difficult to diagnose, form of conversion disorder presenting as unilateral motor weakness with or without sensory deficits. We report four patients who required inpatient rehabilitation for hysterical hemiparesis, a diagnosis for which there is little information regarding rehabilitation management. In all cases, an extensive acute care evaluation including multiple imaging studies failed to identify a new neurologic lesion. All patients had rapid functional improvement using functional and behavioral therapies and extensive psychosocial support (mean length of stay of 11 days; mean Functional Independence Measure [FIM] gain of 22; mean discharge FIM of 112), consistent with other published reports of rehabilitation of conversion disorder. Evaluation of these cases reveals consistencies regarding presentation, psychosocial history, and rehabilitation course that can aid clinicians in making the diagnosis. Rehabilitation strategies for hysterical hemiparesis are reviewed.

Jean-Martin Charcot's contributions to the interface between neurology and psychiatry

Although much has been written about Jean-Martin Charcot (1825-1893) as a neurologist and his commitment to the hysterics of the Salpêtrière, his influence on modern psychiatric thought has been misunderstood. His contributions range from the diagnosis and understanding of certain aspects of hysteria, which influenced psychoanalysis, to insights into the psychopathology of trauma that foreshadow modern concepts of post-traumatic stress disorder and somatoform disorders. This article reviews these aspects in the context of his contributions as a founder of modern neurology, neuropathology and proponent of the anatomo-clinical approach.

Clinical characteristics of patients with motor disability due to conversion disorder: a prospective control group study

OBJECTIVES

Previous studies have suggested associations between conversion and many different clinical characteristics. This study investigates these findings in a prospective design including a control group.

METHODS

Thirty consecutive patients with a recent onset of motor disability due to a conversion disorder were compared with a control group of patients with corresponding motor symptoms due to a definite organic lesion. Both groups had a similar duration of symptoms and a comparable age and sex profile and were assessed on a prospective basis. Background information about previous somatic and psychiatric disease was collected and all patients were assessed by means of a structured clinical interview linked to the diagnostic system DSM III-R, the Hamilton rating depression scale, and a special life events inventory.

RESULTS

The conversion group had a higher degree of psychopathology with 33% of the patients fulfilling the criteria for psychiatric syndromes according to DSM-III-R axis I, whereas 50% had axis II personality disorders compared with 10% and 17% respectively in the control group. Conversion patients also had significantly higher scores according to the Hamilton rating depression scale. Although patients with known neurological disease were not included in the conversion group, a concomitant somatic disorder was found in 33% of the patients and 50% complained of benign pain. The educational background in conversion patients was poor with only 13% having dropped out of high school compared with 67% in the control group. Self reported global assessment of functioning according to the axis V on DSM IV was significantly lower in conversion patients, who also registered significantly more negative life events before the onset of symptoms than controls. Logistic regression analysis showed that low education, presence of a personality disorder, and high Hamilton depression score were significantly associated with conversion disorder.

CONCLUSION

The importance of several previously reported predisposing and precipitating factors in conversion disorder is confirmed. The results support the notion that conversion should be treated as a symptom rather than a diagnosis and that efforts should be made in diagnosing and treating possible underlying somatic and psychiatric conditions.

Laterality in somatization

OBJECTIVE

To identify whether there is a lateralized pattern in somatic symptoms related to emotional disturbances.

METHOD

Sixty-one patients with depressive disorders, anxiety disorders, and somatization disorders were examined for the lateralized distribution of somatic symptoms in the body and its relationship to the severity of anxiety and depression.

RESULTS

The chief somatic symptoms presented significantly more on the left side than on the right side of the body. Headache and other forms of pain, especially, occurred more on the left side. There was no significant difference between left-sided and right-sided groups in demographic variables such as age, gender, marital status, education level, diagnosis, and duration of illness. The scores on Hamilton's anxiety scale or Hamilton's depression scale were higher in the left-sided group than the right-sided group, although the difference was not statistically significant.

CONCLUSIONS

These results suggest that the right hemisphere of the brain is more involved then the left with somatization symptom formation related to emotional disturbances.

Hysteria: A clinical and sociodemographic profile of 40 patients admitted to a Teaching Hospital, 1985-1995

This is a retrospective clinical study of 40 inpatients diagnosed as suffering from hysteria, as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM III-R), admitted to King Khalid University Hospital at Riyadh over a period of 10 years (1985-95). The female:male ratio was 3:1, 80% were less than 30 years of age and 60% were single. Hysterical conversion was the most common type (95%), whereas hysterical dissociation was rare (2.5%). A stressful situation preceded the onset of symptoms in 62.5% of the cases. Twenty-five percent of the patients were clinically depressed. The typical histrionic personality was rare.

Conversion disorder revisited

Fifty four consecutive subjects diagnosed as Hysteria (300.1 according to ICD-9), were taken up for study, to examine the usefulness and validity of Lazare's criteria and explore its clinical utility in diagnosing conversion disorders. Lazare's validation score was computed for each subject, and the specificity, sensitivity, positive predictive validity and misclassification rates were computed for different cut off scores. A cut off score of 5 on Lazare's validation criteria gave good sensitivity (75%) but only modest specificity (41%). The individual criteria showed variation in presence between 18% and 68%, and some of these such as "disturbed sexuality" and "secondary gain" were felt to require redefining. The study of patterns of previous history of organic illness, physical findings on clinical examination, lateralization of symptoms, handedness and followup status indicated important association between hysteria and organicity.

Investigation of unilateral sensory or motor symptoms: frequency of neurological pathology depends on side of symptoms

The records of 82 patients who had undergone inpatient neurological investigation for unilateral motor symptoms, sensory symptoms, or both, without definite neurological signs, were reviewed. Diagnosis of a physical disorder was more frequent if symptoms were on the right side rather than on the left (odds ratio (OR) = 7.7, 95% confidence interval (95% CI) 2.6-23), and in males than in females (OR = 3.0, 95% CI 1.1-8.3).

The consequences of experimentally induced and chronic unilateral pain: reflections of hemispheric lateralization of emotion

In a series of three studies with right handed subjects, left side pain is tolerated less well than right side pain with a cold pressor, and results in greater emotional disturbance, both with a cold pressor and in chronic pain patients. In the second study where comparisons are made with non-stimulated controls, acute left side pain results in higher state anxiety scores than controls; right side pain and control groups are comparable. The differences between the reactions to left and right side pain are consistent with activation of the emotional properties of the hemisphere contralateral to the painful stimulation.

Freud's brain: toward a unified neuropsychodynamic model of personality and psychotherapy

Neuropsychological findings and principles are not by themselves sufficient to provide definitive answers to broad questions of personality, psychopathology, or psychodynamics, nor should they be seen as attempting to usurp other approaches. This review has briefly noted some of the directions in which neuropsychology is being applied to psychoanalysis and psychodynamic personality theory, as well as to clinical practice. The purpose of any model is to try to weave disparate observations and findings into a coherent theoretical framework that can be productively employed for further clinical and research purposes. To this end, the neuropsychodynamic approach can contribute. Man--as Freud recognized--is neither "organic" or "functional." He is both, and our commitment to psychological knowledge must entail a search for unities.

Psychophysiological investigations of patients with unilateral symptoms in the hyperventilation syndrome

Anxiety states sometimes lead to hyperventilation (HV) which may, in turn, give rise to a variety of physical symptoms. One way in which HV may present is with unilateral somatosensory symptoms, often left-sided. We report nine such cases. The mechanisms of lateralisation was examined using EEG and bilateral somatosensory evoked potentials which were carried out before and after HV. No difference in conduction velocity was found between affected and unaffected arms, but non-specific abnormalities were frequently noted in the EEGs. The results support the role of a central rather than a peripheral mechanism in the production of unilateral symptoms in HV.

Laterality of hypnotic response

In an investigation of hemispheric activity during hypnosis, a total of 1269 Ss received hypnotizability scales containing suggestions targeting the left or right side of the body. There were no consistent differences in response strength on the left compared to the right side. Nor were there differences in hypnotizability between right- and left-handed (and ambidextrous) Ss, or between Ss who sat on the left versus right side of the testing room. Definitive evidence of lateralized cerebral activity associated with hypnosis and hypnotizability can only come from direct neuropsychological, electrocortical, or brain-imaging investigations.

Chlorpromazine and the lateralisation of the perception of emotion

In a double-blind design, sixteen volunteer students were administered 50 mg of chlorpromazine or a placebo in tablet form on separate occasions, two hours prior to testing. The test was a lexical decision paradigm involving unilateral presentation of pairs of neutral, positive and negative emotional words and nonwords to the left or right visual fields. Reaction time to identify words and nonwords was recorded. Neutral stimuli were processed faster in the left hemisphere, while negative stimuli were processed faster in the right hemisphere. Chlorpromazine improved speed of response for neutral stimuli presented to the right hemisphere and for affective stimuli presented to the left hemisphere. Thus chlorpromazine seems to benefit right hemisphere processing of nonaffective stimuli and benefit left hemisphere processing of affective stimuli. Chlorpromazine appeared to have a different impact on neutral and affective words, and on the right and the left hemispheres. The general effect of chlorpromazine was to reduce lateralisation. It was suggested that this occurred because chlorpromazine blocked dopamine and possibly other neurotransmitters.

Psychogenic disorders in neurology: frequency and clinical spectrum

Among 4470 consecutive neurological inpatients presenting "with typical neurological symptoms" 405 (9%) were found to have psychogenic rather than neurological dysfunction of the nervous system as the primary cause of admission. This probably represents a conservative figure, since secondary and minor pseudoneurological symptoms were not included. Retrospective analysis of these cases showed that pain was the most common psychogenic symptom, followed by motor symptoms (in particular stance and gait disturbances), dizziness, psychogenic seizures, sensory symptoms, and visual dysfunction. Unilateral motor and sensory symptoms were equally distributed to the left and right side of the body. Psychiatric abnormalities in these patients were heterogenous. Depressive syndromes were most common (38%), whereas hysterical features were less frequent than expected (9%). On discharge, improvement was significantly better for patients with recent onset of symptoms (2 weeks or less) than for those with longstanding disturbances. Short-term outcome was best for motor symptoms and worst for pain. Improvement was independent of psychiatric findings, coexistence of a neurological disease, age, and sex.

Lateralization of chronic facial pain: fact or fiction

Previous studies have shown that pain is generally reported more on the left side of the body. It has been hypothesized that patient report of left pain dominance may be due to the right hemisphere being less efficient in processing cutaneous sensory input while being dominant for emotional experience as compared with the left hemisphere of the brain. Only in cases of trigeminal neuralgia has self-report of pain been lateralized to the right side. Due to previous research findings, we postulated that other facial pain diagnoses may demonstrate a right-sided dominance due to the lack of neural crossover in the facial region. The results of the study found no significant difference between self-report of right- and left-sided facial pain within four diagnostic categories. It was concluded that the results of right lateralized pain with trigeminal neuralgia should not be generalized to the facial pain population as a whole.