Genetic studies in neurology

The use of either direct or indirect genetic analyses in neurology is becoming ever greater as more genes are identified thanks to the human genome project. Often the methodologies are complex and difficult to understand. The aim of this review is to present various approaches to molecular diagnosis using several different inherited neurological diseases as examples. These include inherited mitochondriopathies, monogenetic disorders like trinucleotid repeat instability syndromes, duplication anomalies and specific point mutations as well as heterogenetic diseases such as limb girdle dystrophy and familial amyotrophic lateral sclerosis. Possible pathogenetic implications can now be proposed as the basis of new therapeutic modalities.     

The neurology of diabetes

Diabetic neuropathy, ranging from reversible mononeuropathies to irreversible and progressive autonomic neuropathy, is the most frequent neurological complication of diabetes. Diabetes also affects the central nervous system and manifestations vary from stroke to paroxysmal disorders related to fluctuations in blood glucose levels.     

Problems of perinatal neurology

An analysis of more than 1000 cases of early organic brain lesions has demonstrated that in 54% of them the etiology of neurological disturbances was an antenatal pathology, in 38%-intranatal and in 8%-postnatal. The prevention of perinatal disorders of the nervous system is considered as a complex problem including measures of health prevention for the future mothers, control over the development of pregnancy, perfection of obstetric aid, effective measures for the prevention of tissue hypoxia and its sequalae, elaboration of methods of rehabilitative therapy, work with personnel.     

The neurology of dyslexia

Developmental dyslexia is a heterogeneous disorder in which the prominent manifestation is a discrepancy between reading achievement and intelligence. There is no serious auditory, visual, psychiatric, social or educational factor that could be responsible of the discrepancy. Males are more often affected than females. It is a pervasive condition but with adequate help and spontaneous compensation, reading ability may improve. Neuroimaging, mainly MRI, allows to demonstrate in two thirds, an absence of the usual symmetry of the planum temporale favoring the left side. Twenty to 25% of the remaining cases show asymmetry of the right side. Etiology is unknown but heredity plays an important role. The pathology of dyslexia has revealed abnormalities of the cerebral cortex focal four-layer microgyria, microdysgenesis and arteriovenous malformations. Galaburda hypothesises that a pre or perinatal adverse event produces a basic cognitive, progressive alteration, that eventually invades the perceptual elements (visual, phonological, semantic-syntaxic difficulties). Heilman, Voeller and Alexander propose a motor-articulatory feedback hypothesis.     

Postgraduate training in neurology

Neurology is considered to be an independent special medical field closely related to internal medicine, neurosurgery and psychiatry clinically, and various basic neurosciences. Neurology training programs between U.S.A. and Japan were compared, and the possibility of Japanese training programs were proposed.     

Platelet aggregation inhibitors in neurology

This literature review reports on secondary prevention of ischaemic stroke. The aim of secondary prevention is to protect patients who belong to a risk group from the occurrence of brain infarction. Symptomatic patients with a demonstrated carotid artery stenosis of 70% and more will most probably benefit from carotid endarterectomy if performed by a skilled surgeon in the absence of contraindications. Oral anticoagulant drugs play a minor role in the medical prevention of brain infarction. Antiplatelet drugs, however, have been in use for almost two decades and (meta-)analysis of clinical trials points to acetylsalicylic acid as a drug with a modest but certain contribution of about 15% in the endpoint reduction, even at lower dosages. The addition of dipyridamole to classic acetylsalicylic acid dose appears to increase the endpoint reduction to 30%. Neither dipyridamole nor sulfinpyrazone as monotherapy have been demonstrated to be efficacious in the secondary prevention of ischaemic stroke. Ticlopidine seems a promising alternative for acetylsalicylic acid in those patients who suffer adverse effects from acetylsalicylic acid. Ticlopidine itself, however, has a number of side-effects that limit its application. New clinical trials are under way in order to improve the efficacy of drug treatment in the secondary prevention of brain infarction.     

Acute and critical care in neurology

When subjects select a prime from a visual display while leaving a distractor prime unselected, response time (RT) or response accuracy to a subsequent probe may be impeded if the distractor prime and probe are identical, or if they are related to one another. This phenomenon, negative priming (NP), has obvious implications for understanding perceptual selection. However, it is not known whether NP results from other kinds of selection processes. The present studies were designed to investigate whether NP occurs when primes are selected from working memory rather than from a visual display. In the two experiments, the subjects memorized two primes, selected one prime for further processing, and classified the contents of a probe display. Significant NP occurred in both Experiments. In Experiment 2, however, NP occurred only under easy-selection conditions; the effect was reversed under difficult-selection conditions. The findings indicate a role for NP in memory processing, but contrast with the results from perceptual selection studies showing greater NP under difficult-selection than under easy-selection conditions. The present finding suggests a complex and perhaps strategy-dependent relationship between memory selection difficulty and NP.     

Sleep disorders in neurology: hyposomnia

Sleep disturbances are an important health problem; about 20-33% of the population suffer from hyposomnias (lack of sleep). Hyposomnias often accompany neurological disorders (head traumas, chronic cephalea, pain, cerebrovascular and neuromuscular disorders, M. Parkinson, and dementia). Slow wave sleep decreases, arousals increase, and sleep is fragmented; these types of hyposomnias are treated by treatment of the basic neurological disease. Some sleep disturbances (e.g. sleep apneas) are a risk factor for cerebrovascular disorders.     

Measuring quality of care in neurology

Neurologists are being asked to incorporate methods into daily practice that measure quality of care. Standards of care are increasingly being defined using evidence-based assessments of neurological literature. To evaluate quality of care, a widely accepted and useful model considers the structure, process, and outcomes of care. Outcomes, the impact of care on patients' health, should include measures of mortality, morbidity, disability, patient functioning and well-being (health-related quality of life), and patient satisfaction with care. A variety of private organizations and government programs exist to encourage documentation and promotion of high quality of care. This explosion in quality information is not yet standardized, so that much confusion exists about appropriate data elements to be measured. The challenge is to collect, summarize, and disseminate practical data useful to neurologists and the purchasers and consumers of our services.     

Sleep disorders in neurology. Hypersomnia

Hypersomnia (excessive sleepiness) accompanies many diseases. 14% of the total Austrian population regularly have problems staying awake during the day or are prone to taking spontaneous naps. Hypersomnia is a symptom of the sleep apnea syndrome, which is a risk factor for cerebrovascular disorders. Daytime sleepiness is also a characteristic symptom of narcolepsy, idiopathic hypersomnia, episodic hypersomnia, and many more neurological or psychiatric disorders; it can also be drug induced. Involvement of brain structures which are essential for the regulation of the sleep wake cycle as a result of neurological disorders can likewise lead to hypersomnia. Symptomatic treatment is necessary when treatment of the causal factors is not possible or no improvement has been achieved.