Obsessive-Compulsive Disorder and Tourette's Syndrome

The Science of Mental Health

Steven E. Hyman, Steven E. Hyman

• Editorial: Routledge
• Año: 2022
• ISBN:
  9781136768323
• Edición: 1
• Categoría: Education
• Categoría: Inclusive Education

First published in 2002. Obsessive-compulsive disorder (OCD) and Tourette's syndrome (TS) are treated together in this volume because symptoms of each often co-occur and because there are substantial overlaps in genetic risks and possibly in the neurobiology underlying these disorders.

Obsessive-Compulsive and Other Behavioural Changes with Bilateral Basal Ganglia Lesions

A Neuropsychological, Magnetic Resonance Imaging and Positron Tomography Study

by D. Laplane¹, M. Levasseur², B. Pillon³, B. Dubois³, M. Baulac¹, B. Mazoyer², S. Tran Dinh⁴, G. Sette², F. Danze⁵, J. C. Baron²

SUMMARY

Eight patients are reported who shared the combination of bilateral basal ganglia lesions and a frontal lobe-like syndrome. The main features were inertia and loss of drive, with preservation of intellectual function. Some patients showed stereotyped activities with compulsive and obsessive behaviour which were sometimes highly elaborate in pattern. Extrapyramidal clinical signs were absent or mild. Brain damage, related to anoxic or toxic encephalopathy, was demonstrated by CT scans and MRI. The lesions appeared to be confined to the lentiform nuclei, particularly affecting the pallidum, although there was generalized brain atrophy in 2 cases. Positron emission tomography (PET) in 7 patients revealed hypometabolism of the prefrontal cortex relative to other parts of the brain. The PET studies suggest dysfunction of the prefrontal cortex as a result of damage to the lentiform nuclei. These clinical, anatomical and functional observations emphasize the role of the circuits linking the prefrontal associative cortex and some specific areas of the neostriatum, including the pallidum. The existence of distinct nonoverlapping circuits in the motor field or in the associative field can explain the fact that basal ganglia lesions may give rise to a clinical picture that is either purely motor, purely behavioural (as in some of our patients), or both. Similarities existed between some symptoms found in our patients and certain features of major psychiatric illnesses such as severe depression, catatonic schizophrenia, and obsessive-compulsive disorder. This raises the hypothesis that some aspects of these psychiatric disorders could be related to structural and physiological disturbances in the systems linking the frontal associative cortex and the basal ganglia.

INTRODUCTION

The symptoms reported in cases of damage to the lentiform nucleus generally consist of motor disturbances (Marsden, 1982). We have previously reported instances where patients with bilateral lesions of the lentiform nuclei without or with very mild extrapyramidal symptoms, presented unusual behavioural abnormalities (Laplane et al., 1981, 1982, 1984). The symptoms, which were summarized as a loss of drive’, included a marked decrease in spontaneous activity, a loss of affect, and a notable reduction of spontaneous thought content. Also remarkable was the observation that their inertia was apparently reversible by external stimulation, such as the incitement by a relative. Moreover, on neuropsychological testing, intellectual capacities were largely preserved, except for a memory defect in 1 of the 3 cases.

The attributability of these disturbances to lesions of the lentiform nuclei was strongly suggested by the CT scan findings, but doubt remained as to the possibility of diffuse or multifocal brain damage, in spite of the normality of EEG recordings and the absence of other visible lesions on the scan images. In addition, the question was raised as to how these limited subcortical lesions could induce such behavioural changes. The hypothesis of a functional impairment of the prefrontal cortex was made on the basis of strong clinical resemblances between our patients’ symptoms and a frontal lobe syndrome. This similarity, and the absence of motor disturbance, led to the suggestion that the lesions might have affected the ‘association’ circuits linking some compartments of the basal ganglia and the prefrontal cortex. Finally, the additional presence, in 2 of these 3 patients, of obsessive-compulsive behaviour was noteworthy, representing a likely example, if confirmed by further cases, of psychiatric symptoms being produced by focal brain impairment.

Since then, 2 other cases have been reported by Ali-Cherif et al. (1984) and we have now been able to examine 5 new similar cases. It was possible to perform magnetic resonance imaging (MRI) and positron emission tomography (PET) in 7 of our 8 cases, and in the light of this additional material, some progress can be made towards the understanding of the clinical features.

Material and Methods

All 8 patients were selected on the basis of symptoms of inertia, reversible under stimulation and the presence of lesions of the lentiform nuclei on CT scans.

Neuropsychological testing

Intellectual function and memory. The following tests were selected: the Wechsler Verbal Scale, the Raven’s 1938 Progressive Matrices (PM 38) and the Wechsler Memory Scale. Patients were allowed unlimited time to perform these tests.

Frontal lobe function. The simplified version of the Wisconsin Card Sorting test (Nelson, 1976), tests of verbal fluency (names of animals in 1 min. words beginning with the letter M in 1 min) (Benton, 1968), and a graphic series (Luria, 1966) were chosen because they were known to be sensitive to frontal lobe dysfunction. Behavioural abnormalities (prehension, imitation and utilization), observed in patients with frontal lobe lesions (Lhermitte, 1983: Lhermitte et al., 1986) were also evaluated.

Linguistic, gestural and drawing tests. These included the naming of objects, writing a sentence on dictation, calculation, execution of symbolic gestures, and the copying of a cube or the Rey-Osterrieth complex figure.

The 15 objects test (B. Pillon et al., unpublished). This visual discrimination task, consisting of 15 superimposed images of objects, was chosen in order to evaluate cognitive slowing.

Objective personality tests. The Minnesota Multiphasic Personality Inventory (MMPI) or a self-rating depression scale (Pichot et al., 1984) was used.

Magnetic resonance imaging

In 7 patients (Cases 2–8), MRI was performed on a superconducting MR imager operating at a Held strength of 1.5 T. Coronal and horizontal (Virschow’s plane) 5 mm slices were taken every 7.5 mm. T1 and T2 weighted sequences were used. Real-size printed photographs were obtained from the films and were compared with atlases (Salamon and Huang, 1980, f...