Aspects of biochemical differentiation in the central nervous system

A demonstration of cell-specific patterns of development in the immature CNS is provided by examples of characteristic, cellspecific time-courses of enzyme development in different classes of brain cells isolated in highly purified form by bulk-separation from the cerebral and cerebellar cortex of the growing rat. The enzymatic analysis was carried out at the level of the nerve and glial cell lysosomes and mitochondria, two subcellular organelles crucial to the economy of all cells. The findings reveal rather similar developmental patterns for the lysosomal hydrolase N-acetyl-β-D-glucosaminidase in neurons and glial cells of the cerebral cortex as well as in two different cerebellar nerve cell types, the Purkinje and the granule cell. However, significant differences in the post-natal chronology of development of the mitochondrial enzyme α-glycerophosphate dehydrogenase were noted between cortical nerve and glial cells, the glial enzyme exhibiting 6-fold higher levels of activity than the neuronal one throughout the first month of postnatal life. The findings emphasize the feasibility as well as the necessity of studies aimed at the elucidation of the cell-specific aspects of the biochemistry of developing nerve and glial cells.     

Characteristics of body excursion during a static upright posture in elderly people with central nervous system disorders and with other disorders from the viewpoint of body-excursion parameters

This study aimed to compare characteristics of body excursion of healthy elderly and elderly people with disorders. The participants were 38 healthy elderly who were at home (Healthy Elderly group) and 24 elderly people with disorders. The latter consisted of two groups: 12 in the Central Nervous System Disorders group with vestibular organ or central nervous system disorders, and 12 in the Other Disorders group with other system disorders. 34 parameters were selected from six domains: distance, distribution of amplitude, area, velocity, power spectrum, and vector. When compared with the Healthy Elderly group, the Central Nervous System Disorders group was judged abnormal on many parameters and showed large and quick body excursion characteristics, particularly in left-right excursion. The Other Disorders group showed different characteristics in the size of the left-right excursion and velocity of the front-back excursion. However, compared with the Central Nervous System Disorders group, very few people in the Other Disorders group were judged abnormal, and they showed slower velocity for front-back excursion.     

Stiff-person syndrome: autoimmunity and the central nervous system

Stiff-person syndrome (SPS) is a rare disease of severe progressive muscle stiffness in the spine and lower extremities with superimposed muscle spasms triggered by external stimuli. Patients with SPS are often referred for psychiatric evaluation and the psychiatrist may be the first to diagnosis SPS. Psychosocial stressors often precede the first manifestations of the disease; depression, anxiety, and alcohol abuse are comorbid illnesses. The identification of an association with antibodies to glutamic acid decarboxylase (GAD) was invaluable for definitively establishing a pathological basis for the disease; antibodies to amphiphysin and gephyrin are also found in cases of SPS but at much lower frequencies. Whether the antibodies inhibit GAD activity in vivo, target GAD-expressing neurons for immune-mediated destruction, are part of a wider immune process, or are merely a marker for destruction of GAD-expressing neurons by an independent neurodegenerative process is not yet clear. Both electromyography and the detection of GAD antibodies are useful in establishing a diagnosis of SPS. Treatment of SPS includes the use of immunomodulating therapies (plasmapheresis and intravenous immunoglobulins) and symptomatic treatment with benzodiazepines and baclofen. The use of tricyclic antidepressants and rapid withdrawal from therapy should be avoided.     

Adrenergic pharmacology: focus on the central nervous system

Norepinephrine and epinephrine are involved in the control of several important functions of the central nervous system (CNS), including sleep, arousal, mood, appetite, and autonomic outflow. Catecholamines control these functions through activation of a family of adrenergic receptors (ARs). The ARs are divided into three subfamilies (alpha1, alpha2, and beta) based on their pharmacologic properties, signaling mechanisms, and structure. ARs in the CNS are targets for several therapeutic agents used in the treatment of depression, obesity, hypertension, and other diseases. Not much is known, however, about the role of specific AR subtypes in the actions of these drugs. In this paper, we provide an overview of adrenergic pharmacology in the CNS, focusing on the pharmacologic properties of subtype-selective AR agonists and antagonists, the accessibility of these drugs to the CNS, and the distribution of ARs in different areas of the brain.     

MR imaging of fetal central nervous system abnormalities

Ultrasound is the screening modality of choice for fetal imaging. However, when additional information regarding fetal anatomy or pathology is needed, fast MR imaging is increasingly being used as a correlative imaging modality. Performances of high quality sonographic and MR examinations as well as interpretation by individuals familiar with prenatal diagnosis are important factors for optimal parental counseling. MR imaging frequently adds additional information regarding fetal central nervous system anomalies beyond that available with ultrasound. This information commonly changes patient counseling, and at times patient management.     

Learning disabilities and central nervous system involvement.

The relation of damage to the central nervous system to learning disabilities remains a continuing issue. This study explored how learning disable children fare on the Visual Retention Test. Analysis of correct scores and errors for the 24 children responding to Administration A would ordinarily suggest a primary relationship (t = 2.60, p less than .02; t = 4.01, p less than .001, respectively). However, since extensive medical and case history material yielded no evidence of cerebral injury or disease and since the impact of short-term memory (Administration D) led to no further performance decrement (t less than 1.00), additional research must determine a more precise understanding of perceptual dysfunction and the role of short-term memory in regard to learning disabilities.     

Functional effects of neural grafting in the mammalian central nervous system

Grafts of fetal and nonfetal brain tissues have been successfully implanted into the mammalian central nervous system (CNS). The functional effects of neural grafting in the CNS of rodents and nonhuman primates in a variety of situations are reviewed. Research areas discussed included the effects of dopamine-rich grafts in animal models of Parkinson's disease and acetylcholine-rich grafts in animals with lesions of the cholinergic pathways to the neocortex and hippocampus. Graft effects also are examined in aged animals and genetic mutants. In addition, the effects of neural grafts on circadian rhythmicity, reproductive functions, and conditioned taste aversion are discussed. The beneficial functional effects of neural grafts and the possible mechanisms and implications for these effects are discussed, including the possibility that the CNS exhibits a regional biochemical specificity that influences the outcome of neural graft procedures.     

The functional state of the central nervous system in chemical stress

The psychosocial and physical factors, including chemical ones, which affect the human organism are considered by some authors to be stress factors which affect the functional state (FS) of the central nervous system (CNS). We calculated correlations among the clinical, psychological/psychometric, and quantitative electropsychological (QEEG) variables of the functional changes of the CNS in chemical stress. These data were based on occupational contact with lead as experienced by 402 workers, with styrene by 96, with shale-oil products by 252, with organic solvents by 77 workers, and a control group of 145 workers in different age groups. The QEEG data of 77 patients were analyzed to determine the chronic neurotoxic effects of industrial chemical substances by diagnosing the functional changes at the syndrome level. We concluded that occupational chemical factors impact the functional state of the CNS. During chemical stress -activity and total cerebral bioelectrical activity (BA) decreases. The use of psychometric/ psychological and QEEG methods makes it possible to diagnose the changes of the CNS as hypersthenic, hyposthenic, and organic psychosyndromes.     

Listeriosis of the central nervous system in children beyond the neonatal period

Observations on three children with neurolisteriosis (one case of meningitis, two cases of meningoencephalitis, each Serovar 4 b), show that even after the neonatal period, listeriosis must not be ignored in the process of diagnosis and therapy. It is the bacteriological examination of the cerebrospinal fluid, together with the blood culture, and not clinical symptoms and serology that guarantee a timely diagnosis and therapy (ampicillin and gentamicin).     

Environmental complexity and central nervous system development and function

Environmental restriction or deprivation early in development can induce social, cognitive, affective, and motor abnormalities similar to those associated with autism. Conversely, rearing animals in larger, more complex environments results in enhanced brain structure and function, including increased brain weight, dendritic branching, neurogenesis, gene expression, and improved learning and memory. Moreover, in animal models of CNS insult (e.g., gene deletion), a more complex environment has attenuated or prevented the sequelae of the insult. Of relevance is the prevention of seizures and attenuation of their neuropathological sequelae as a consequence of exposure to a more complex environment. Relatively little attention, however, has been given to the issue of sensitive periods associated with such effects, the relative importance of social versus inanimate stimulation, or the unique contribution of exercise. Our studies have examined the effects of environmental complexity on the development of the restricted, repetitive behavior commonly observed in individuals with autism. In this model, a more complex environment substantially attenuates the development of the spontaneous and persistent stereotypies observed in deer mice reared in standard laboratory cages. Our findings support a sensitive period for such effects and suggest that early enrichment may have persistent neuroprotective effects after the animal is returned to a standard cage environment. Attenuation or prevention of repetitive behavior by environmental complexity was associated with increased neuronal metabolic activity, increased dendritic spine density, and elevated neurotrophin (BDNF) levels in brain regions that are part of cortical-basal ganglia circuitry. These effects were not observed in limbic areas such as the hippocampus.     

Rasmussen's syndrome: intractable epilepsy and progressive neurological deterioration from a unilateral central nervous system

Rasmussen's syndrome (chronic encephalitis with epilepsy) is a rare neurological disorder of unknown cause characterized by severe epilepsy, hemiplegia, dementia, and inflammation of the brain, and progressive functional and structural destruction of a single cerebral hemisphere. While one mechanism underlying the pathogenesis of Rasmussen's encephalitis has been hypothesized to be mediated by production of excitotoxic GluR3 autoantibodies to the a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor, other neuropathological etiologies have also been indicated. Proposed therapies have included antiepileptics, steroids, antiviral agents, alpha-interferon, and immunoglobulin. The mainstay of therapy is surgical hemispherectomy. To date, no medical therapies have permanently halted neurologic deterioration.     

"Slow virus" infections and degenerative diseases of the central nervous system]

Slow virus infections of the central nervous system are produced by both conventional and unconventional viruses. Diseases of the central nervous system which are produced by unconventional viruses are discussed. They are kuru and the Creutzfeldt-Jacob disease. Mention is also made of the fact that these disease may be transmitted to animals which allows an infectious genesis to be assumed. The author also discusses the clinical symptomatology, the results of anatomical and pathological examinations, and the mechanism of transmission of the disease from one human being to another. Slow virus infection as a cause of other neurological diseases is also dealt with by the author in her present paper.     

Delirium and isolated angiitis of the central nervous system: a case report and review

Central nervous system (CNS) vasculitis is a rare entity, especially when it occurs in isolation; it is seen more commonly as part of a multisystem vasculitis. Common presenting symptoms include persistent headache, encephalopathy, and multifocal signs. We discuss the case of a 68-year-old female who presented twice in 1 month with confusion and choreaform movements. Extensive workup was negative for a connective tissue disease or other conditions in the differential, including neurosarcoidosis, Creutzfeldt-Jakob disease, and neurosyphilis. The only significant findings were elevated erythrocyte sedimentation rate, inflammatory signs in the CNS, and diffuse slowing of the electroencephalogram. A presumptive diagnosis of isolated angiitis of the central nervous system (IACNS) was made and the patient was successfully treated with steroids. She recovered fully with no residual symptoms. The diagnosis of IACNS is often difficult given there are no definitive laboratory investigations or pathognomonic presentation. However, a series of signs, symptoms, and laboratory findings have been proposed that are helpful in making the diagnosis. To our knowledge, IACNS presenting primarily with delirium has not been previously reported in the literature. The diagnosis of IACNS is purely speculative for this case, as the gold standard for diagnosis, a leptomeningeal cortical biopsy, was not performed.