Acta neurologica Scandinavica. Supplementum最新文献

The empty sella turcica is defined as a sella which, regardless of its size, is completely or partly filled with cerebrospinal fluid. An empty sella of normal size is a frequent and probably normal finding in unselected autopsy series. In clinical series an empty sella usually appears enlarged and is often associated with a variety of clinical disorders, constituting the so-called empty sella syndrome. Several causes of an enlarged empty sella have been suggested: a congenitally missing (deficient) sellar diaphragm with or without altered cerebrospinal fluid dynamics, previous pituitary gland hypertrophy or the outcome of a pituitary tumor necrosis. Increased intracranial pressure will induce a sellar enlargement in some patients and, consequently, also the emptiness. This pathogenesis is, however, applicable only in a minority of patients with an empty enlarged sella. Data from the literature and from own studies suggest that the enlarged empty sellae and the associated findings in the majority of cases are caused by spontaneous necrosis of a previous pituitary adenoma. This theory explains the frequent presence of pituitary insufficiency, pituitary hypersecretion, and visual field defects in patients with an empty sella. Furthermore, it offers an explanation of the finding of an empty enlarged sella in some patients with non-traumatic cerebrospinal fluid rhinorrhea and probably also benign intracranial hypertension. Thus, an empty enlarged sella is a stage in the spontaneous course of some pituitary adenomas and the associated findings constituting the empty sella syndrome are an occasional part of the clinical presentation of pituitary adenomas.

With the growing importance of occupational behavioural neurotoxicology the demand for a standardized and reliable cognitive test battery has become urgent. The present study deals with the compilation of a test battery, the purpose of which is to be sensitive to mild brain dysfunction and suitable for modern microcomputer administration and scoring. The battery comprises tests of learning and memory functions specific for each brain hemisphere (Face Recognition Test and Number Learning Test), visuomotor function separately for continuous and discrete tasks (Figure Drawing Test and Pen-to-Point Test), visuospatial function (Parallelogram Test), visual and auditive perception, attention and vigilance (Bourdon-Wiersma Test and Continuous Reaction-Time Test), and concentration (Continuous Graphics Test). The complete test battery was administered and scored on a slightly modified Tektronix 4052 computer with a Tektronix 4956 digitizer as a peripheral device. The validity of the battery was analysed on the basis of a sample of the normal Danish population (N = 1262) stratified for the ages 30, 40, 50, and 60 years, the two sexes, and residence in one of 11 municipalities in the western part of Copenhagen County. Using a 16-dimensional multivariate model comprising biological, social, psychological, and environmental factors, and also examiner behaviour, statistical analyses confirmed hypotheses of influence by the factors Age, Sex, Schooling, and Social Group, i.e. these factors partially explained the variance in the case of almost all the test parameters. Moreover, psychic stress, as determined in a questionnaire, had explanatory power with tests demanding attention and concentration. Hypotheses of effects on test performance by Smoking Status and psychophysiological diurnal or annual rhythms, i.e. Time of Day, and Time of Year, were confirmed for a few parameters, but the effects differed to some extent from those described in the literature. Alcohol Consumption, Drug Consumption Affecting the CNS, Cardiovascular Diseases or Disorders, Metabolic Diseases or Disorders, CNS Injuries or Disorders, and Occupational Activity Status, all revealed by questionnaire, were not found to show the assumed significant effects on test performance. However, a hypothesis of an effect originating in differences between different examiners' behaviour was confirmed for a number of test parameters, although all the test measurements and scorings were done automatically by computer. On the basis of a re-examination of 19 patients previously diagnosed as suffering from diffuse organic psychosyndrome, the sensitivity of the test battery was estimated to be 0.79. The specificity was estimated to be 0.79 on the basis of the results of the original sample.(ABSTRACT TRUNCATED AT 400 WORDS)

Photosensitivity is a rare phenomenon found, often more or less accidentally, in approximately 5% of epileptic patients. Its pathophysiology still remains largely unsolved and the clinical significance of photosensitivity is controversial. The literature on the subject is impressive, yet predominantly anecdotal. In this thesis we describe the results of an extensive and standardized study of 100 consecutive photosensitive patients with special emphasis on the clinical history, the seizure history and the electrophysiological findings. These are then compared to identical data of an age and sex matched control group, obtained from the same population of epileptic patients, referred to a special (tertiary care) epilepsy clinic. In chapter I, the literature is reviewed and photosensitivity as a special form of "reflex epilepsy" is discussed. A distinction is made between normal and abnormal reactions on intermittent photic stimulation (IPS) during electroencephalographic (EEG) registrations and the criteria of true photosensitivity are formulated. The relation between the presence of photosensitivity during EEG examination and the occurrence of visually-induced epileptic seizures in daily life is discussed. As self-induction of seizures has been associated with photosensitivity, an extensive review, including a special reference list (see appendix A), is given concerning such self-inducing behaviour in photosensitive patients. A review of photosensitivity as a genetic marker and model of epilepsy concludes this chapter. In chapter II the aims of this study are outlined. Some general conceptions about photosensitive epilepsy have become widely accepted in clinical practice without much scientific support, i.e., the idea that the finding of photosensitivity is synonym with the diagnosis of primary generalized epilepsy. Furthermore, photosensitivity is generally believed to be a genetically determined, benign type of epilepsy in childhood and adolescence but when associated with self-inducing behaviour is interpreted as a sign of mental subnormality. Whether or not these conceptions are valid and whether photosensitivity is or is not a special subtype of epilepsy remains unsolved. In this study we thus set out to answer the following questions: A. Are photosensitive epileptic patients different from non-photosensitive patients with epilepsy, with respect to clinical history and, more specifically, to seizure history and family history for seizures? B. Is the degree of photosensitivity, established as photosensitivity range, predictive for the liability to visually-induced seizures in daily life? Are detailed laboratory findings concerning sensitivity to television and black-and-white striped patterns of clinically predictive value, e.g. can patients, liable to TV epilepsy or pattern-induced seizures, be identified by EEG investigations?

In recent years, the possible role of occupational solvent exposure as a cause of chronic effects on the brain has been a matter of increasing concern. The present study was undertaken with the purpose of further investigating this problem, trying to minimize confounding owing to effects of recent solvent exposure and a 'healthy worker' effect. This was accomplished by studying a historical cohort of painters. The material consists of a random sample of 85 painters, and as a non-exposed control group of 85 bricklayers, selected in the same way. Parts of the study are based on this sample supplemented by a sample of 9 painters and 14 bricklayers, selected among subjects with a high degree of complaints on mental impairment. On the basis of a detailed interview on previous solvent exposure, the painters were divided into three groups with low, medium and high solvent exposure, respectively. As signs of organic brain damage we used the degree of dementia and performance in psychometric tests as assessed at a neuropsychological examination; the degree of dyscoordination as assessed from clinical neurological tests; and the degree of cerebral atrophy as assessed from CT-scans of the brain. CT-scans were performed only on a specially selected subsample. The degree of dementia, dyscoordination, and cerebral atrophy increased significantly with the degree of solvent exposure. A similar, but non-significant association was found for the relation between performance in psychometric tests and solvent exposure. The degree of dementia, of dyscoordination, and of cerebral atrophy were positively associated with each other, suggesting that they reflect different aspects of a common underlying factor, an organic brain damage. A review of the literature compared with the results of the present study suggests that a number of studies may have been biased towards negative findings owing to the inclusion in the study material of large proportions of subjects with a solvent exposure that is too little to increase the risk of an organic brain damage. Conflicting results between different studies on performance in psychometric tests may also arise from insufficient adjustment for primary intellectual level.(ABSTRACT TRUNCATED AT 400 WORDS)