Conversion hysteria and dominant hemisphere lesions

The neuropsychiatry of conversion disorder

PURPOSE OF REVIEW

During the past two decades there has been a relative surge of interest in conversion disorder, and a multitude of studies have emerged on the subject. With continuing developments in neuroscience--mainly brain imaging--new applications to conversion disorder are being reported every year.

RECENT FINDINGS

Diagnosis continues to represent a challenge, although neurological signs are increasingly being developed and validated to assist with this. Psychiatric co-morbidity diagnosed according to operational criteria is common. Brain imaging studies have brought some clues to understanding the pathophysiology of conversion disorder.

SUMMARY

Evidence-based medicine requires reliable diagnostic criteria, and attempts have recently been made to validate some of the well known neurological signs of conversion disorder. From a psychiatric point of view, there is a need for greater understanding of the aetiology and mechanisms underlying conversion disorder and its relationship to other psychiatric disorders. Although advances have been made both in diagnostic methods and in the groundwork for a neurobiological model, no clear rationale for treatment is yet available and further research is strongly needed.

Cognitive Impairment Is Not Equal in Patients with Epileptic and Psychogenic Nonepileptic Seizures

PURPOSE

Patients with psychogenic nonepileptic seizures (PNES) and those with epileptic seizures (ES) purportedly have roughly equal neurocognitive deficits. However, recent findings suggest that patients with somatoform disorders exhibit more variable effort on neurocognitive testing than do controls. We reexamined neurocognitive function in patients with ESs and PNES by using symptom validity testing to control for variability in effort.

METHODS

Patients referred for video-EEG monitoring were administered the Word Memory Test (WMT), a measure of symptom validity, as part of neuropsychological evaluation. Patients classified with ictal video-EEG recordings as having ES (n = 41) or PNES (n = 43) were compared on neurocognitive and WMT performance and demographic, psychiatric, and medical variables.

RESULTS

Striking rates of WMT failure were observed in the PNES (51.2%) group, but not in the ES (8.1%) group (p = <0.001) after controlling for false-positive errors. Although the PNES and ES groups reported equivalent neurologic histories, the PNES group exhibited less objective evidence of impairment as measured by valid neuropsychological testing, MRI of the brain, and video-EEG monitoring.

CONCLUSIONS

Many patients with PNES do not put forth maximal effort during neuropsychological assessment. When patients with PNES put forth valid effort, they demonstrate less objective evidence of neuropathologic injury or disease than do patients with ES. The cognitive impairment reported by this group appears to be more a function of motivational (although not necessarily intentional) factors than of verifiable neuropathology.

Conversion hysteria: is it a viable concept?

The notion of conversion hysteria is built around three assumptions to the effect that symptoms can arise without an adequate pathological base, that the patient experiences these symptoms as ''real'' in that they are not consciously feigned, and that psychological distress can be transformed or ''converted'' into physical symptoms. It is argued that the first of these assumptions is valid and that the truth of the second cannot be judged with adequate reliability to make it acceptable as a criterion for classification. The last assumption is questionable in that it is difficult to conceive of a satisfactory explanation as to how the process of conversion might operate.

Cerebral blood flow changes in patients with conversion disorder

We evaluated regional cerebral blood flow in five patients with conversion disorder (three females, two males, mean age+/-S.D.: 29.8+/-9.5 years) with astasia-abasia. The patients underwent single photon emission computed tomography after the injection of 555 MBq of [99mTc]hexamethylpropyleneamine oxime. Uptake ratios between areas of decreased perfusion and normal brain regions were considered significantly decreased when there was a change > or = 10%. Four of the five patients had left temporal and one patient had left parietal perfusion decreases. Uptake ratios ranged from 0.72 to 0.88 (mean+/-S.D.: 0.81+/-0.08). Our findings suggest that alterations in regional brain perfusion may accompany conversion symptoms. Functional imaging may therefore offer a means of elucidating the neural correlates of conversion disorder.

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.