bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrathecal Fibrinolytic Therapy after Subarachnoid Hemorrhage: Dosage Study in a Primate Model and Review of the Literature
Authors: Findlay J.M. , Weir B.K.A. , Kanamaru K. , Grace M. , Gordon P. , Baughman R. , Howarth A. 
Published: July 2016

ABSTRACT:Because of the naturally low fibrinolytic activity of CSF many erythrocytes entrapped in subarachnoid blood clot undergo hemolysis in situ, releasing vasogenic oxyhemoglobin (OxyHb) in high concentrations around the basal cerebral arteries. In order to promote more rapid clearance of erythrocytes from the basal subarachnoid cisterns we are currently investigating intrathecal thrombolytic therapy with human, recombinant, tissue plasminogen activator (rt-PA) in a primate model of subarachnoid hemorrhage (SAH) and cerebral vasospasm (VSP). In the present study 16 monkeys were divided into 4 groups of 4, and each group received a different dose of sustained-release gel rt-PA at the time of experimental SAH. Cerebral angiography seven days later showed that whereas no VSP occurred in the groups receiving 0.5 or 0.75 mg of rt-PA, mild to moderate VSP occurred in the groups receiving 0.125 or 0.25 mg of rt-PA. Analysis of the combined 2 smaller dosage groups revealed significant (P<0.05) reduction of lumen caliber in the clotside internal carotid (C3 and C4), proximal anterior cerebral (A1) and middle cerebral (MCA) arteries. Gross subarachnoid clot remained in all of the animals in the 0.125 and 0.25 mg dose groups, in 2 of the animals in the 0.5 mg dose group, and none of the animals in the 0.75 mg dose group. It was concluded that 0.75 mg of gel rt-PA is sufficient to completely lyse a 4.25 ml SAH and prevent VSP in our primate model. The literature on fibrinolysis and erythrocyte clearance in cerebrospinal fluid (CSF) is reviewed.
Dendritic Pathology: An Overview of Golgi Studies in Man
Authors: Jagadha Venkita , Becker Laurence E. 
Published: July 2016

ABSTRACT:Study of dendritic morphology through Golgi impregnation techniques has significantly furthered our understanding of neuronal development, maturation, and senescence. It has also provided insight into the pathogenesis of a wide spectrum of disease processes ranging from brain malformations to degenerative disorders. Golgi impregnation remains virtually the only method for demonstrating dendritic morphology. It delineates the profile of the individual neuron and its dendritic ramifications with unsurpassed clarity. Although it has been widely applied to experimental neuroscience involving animal tissue, its application to human material has been limited. This review summarizes the information on dendritic development and pathology in the human brain revealed by the use of the Golgi method.
Effect of Knee Joint Angle on a Heteronymous lb Reflex in the Human Lower Limb
Authors: Brooke J.D. , Mcllroy W.E. 
Published: July 2016

ABSTRACT:Altered efficacy, from change in receptor discharge with different positions of the knee, was investigated in a heteronymous lb reflex of the human leg. The electrical stimulus was low threshold, to the common peroneal nerve. The divergence of the group I afferents was studied in the electromyograms (EMGs) of ipsilateral and contralateral thigh muscles. The stimulus evoked ipsilateral, short latency, excitation in the three quadriceps muscles studied and inhibition in the knee flexor semitendinosus (ST), with prior contraction of target muscles. This excitation and inhibition did not alter when studied over the range of the knee joint. The stimulus did not evoke responses in contralateral thigh muscles, contracted or relaxed. It is concluded that (1) any change in convergence from discharge of receptors, during extension of the limb, is small and sub-threshold, and (2) this spinal proprioceptive level of neural control appears to be directed primarily to the single limb.
La variabilité du phénotype dans la dystrophie myotonique de Steinert
Authors: Bouchard Jean-Pierre 
Published: July 2016

ABSTRACT:Phenotype Variability in Myotonic Dystrophy Myotonic dystrophy, best known in the French literature as Steinert disease, is a dominantly inherited disorder. When the gene is fully expressed, it shows a characteristic clinical picture. Myopathy and myotonia are the main features, but this is a systemic disease which may involve many other organs such as the central nervous system, eyes, bones, endocrine system, etc. With the complete picture, physical and behavioral features make the diagnosis easy, only to be confirmed by neurological and ophthalmologic examination and/or electromyography. This work reviews the main clinical signs seen in the classical form of the disease. We also want to stress the variability of that picture. Finally, we describe a new dysmorphic sign in myotonic dystrophy: large prominent cupped auricles. Although not recognized, prominauris has been illustrated in a number of publications on myotonic dystrophy. Three of our adult male patients presenting the congenital form of the disease at birth have been investigated to rule out concomitant fragile-X syndrome. Both syndromes include mental retardation and dysmorphic ears. Our patients show the usual testicular atrophy, whereas the fragile-X syndrome includes testicular hypertrophy. Cytogenetic studies were normal. Old clinical description and new physical signs may lack prestige in the perspective of recent molecular biological breakthroughs, but to recognize the disease and help patients live with it will always be the role of practitioners.
Ascertainment of Informative Alzheimer Disease Families from the IMAGE Project Registry for Genetic Linkage Analysis Studies
Authors: Gautrin D. , Nalbantoglu J. , Lacoste-Royal G. , Grenon M. , Gauthier S. , Bouchard R. , Mathieu J. , Robitaille Y. , Doyon L.-P. , Bergman H. , Cholette A. , de Braekeleer M. , Bouchard G. , Gauvreau D. 
Published: July 2016

ABSTRACT:Genetic linkage analysis requires the identification and documentation of large families with many affected members present, preferably in more than one generation. The IMAGE Project has been establishing a population- based Alzheimer disease (AD) registry in the Saguenay - Lac-Saint-Jean region of the Province of Quebec. The population of this region has a well-documented ancestry, with reliable genealogical records (since 1842) computerized by SORER We have recently begun to investigate the pedigrees of selected probands (definite, probable and possible) from the IMAGE registry in order to identify informative pedigrees for genetic linkage analysis. Interviews were carried out with close relatives of the probands (at least one informant per sibship) to identify secondary AD cases. The questionnaires used pertain to the accuracy of genealogical records, to family medical history and to a retrospective diagnosis of AD for people with cognitive deficits. By these means, we have documented a large extended pedigree in which a total of 15 individuals with cognitive deficits were ascertained over three generations. Of these cases, 7 are still living and there is autopsy confirmation in another one. Computer simulations using the program SIMLINK revealed that this is a potentially informative family for linkage analysis. Horizontal extension of the pedigree to second cousins of the proband is now being carried out. This will render the family IMAGE/1 even more informative in genetic linkage analysis studies.
Strategies for the Identification of Novel Brain Specific Genes Affected in Alzheimer Disease
Authors: Walker D.G. , Boyes B.E. , McGeer P.L. , McGeer E.G. 
Published: July 2016

ABSTRACT:The pathological changes that occur in Alzheimer disease (AD) brain lead to a large loss of various classes of neurons and the production of novel proteinaceous elements such as neuritic plaques and neurofibrillary tangles. For the neuronal loss to occur and these elements to arise, there must be a disturbance in the expression or regulation of genes that code for proteins required for normal cell maintenance, or perhaps even for the expression of genes unique to AD. We describe the construction of a cDNA library from the human substantia innominata and strategies for isolating genes that are expressed differentially between brain regions and which may be affected by AD. Some of the results obtained using these strategies and a preliminary description of a novel brain specific mRNA of 15.5kb, whose expression is increased in AD affected temporal cortex, are presented.
Absence of Responses to Microstimulation at the Hand-Face Border in Baboon Primary Motor Cortex
Authors: Samulack Donald D. , Waters Robert S. , Dykes Robert W. , McKinley Patricia A. 
Published: July 2016

ABSTRACT:Intracortical microstimulation (ICMS) was used to map the primary motor cortex of four adult female baboons, anesthetized with a mixture of halothane and nitrous oxide and supplemented with sodium pentobarbital. The sequence of observed muscle contractions in response to ICMS provided evidence of an orderly mototopic representation of the tongue, face, hand, forearm and upper body. A zone of cortex unresponsive to microstimulation was consistently observed at the border between the face and hand representation of the mototopic map. This zone was observed in all four animals and was consistent over time. Repeated confirmations of the unresponsive nature of these regions were obtained both early and late in the same experiment. No motor-unit responses or muscle contractions were detected by electromyographic (EMG) recording during stimulation of the unresponsive zones. The absence of both visually observed and EMG-recorded contractions and the fact that muscle contractions could be elicited from adjacent regions of cortex with ICMS as low as 1-5 μA provide compelling evidence that the finding reflects a true physiological condition rather than an experimental artifact.
Receptive-field Size of S1 Cortical Neurones is Altered by Methaqualone via a GABA Mechanism
Authors: Hicks T.P. , Kaneko T. , Oka J.-I. 
Published: July 2016

ABSTRACT:Methaqualone (Mtq; quaaludes or 'ludes) is a controlled substance, having a molecular structure related to the imidiazobenzodiazepine series of drugs, that has gained some notoriety recently due to its history of widespread abuse on the street. Users report experiencing peripheral paresthesia and transient numbness on body parts receiving dense cutaneous innervation (lips, fingertips, etc.). Since the receptive-field (RF)-sizes of many primary somatosensory (SI) cortical neurones are controlled by local, gamma-aminobutyric acid (GABA)-mediated inhibitory processes, we tested Mtq to see whether its clinical symptoms might have a basis in an action through central GABA-mediated synaptic processes. This report supports this contention and describes a likely pharmacological mechanism involved as one being related to the Ro 15-1788-sensitive benzodiazepine (Bzd) recognition site(s) of the GABA receptor complex.
The Second Canadian Conference on Multiple Sclerosis
Authors: Weinshenker Brian G. , Nelson Robert 
Published: July 2016

ABSTRACT:The epidemiology of multiple sclerosis (MS) and the planning and interpretation of clinical therapeutic trials were the subjects of a symposium on MS held on June 13, 1989. Several speakers addressed whether MS is a genetic or an environmental disease. An environmental trigger would resolve the relatively low penetrance of the disease in susceptible individuals, although the alternative hypothesis that MS is a multigenic disease would also account for this observation. Clinical trials have to date failed to confirm the efficacy of any immunosuppressive or other agent in the management of progressive MS. Magnetic resonance imaging (MRI) appears to be highly sensitive for monitoring the activity of MS. Preliminary evidence suggests that MRI activity correlates with longitudinal clinical assessments of disability. Immunologic tests, while valuable in determining pathophysiology of MS, have not been strongly correlated with clinical outcome.
Neuropathie Sensitivo-Motrice Héréditaire avec ou sans Agénésie du Corps Calleux: Étude Radiologique et Clinique de 64 Cas
Authors: Mathieu Jean , Bédard Fernand , Prévost Claude , Langevin Pierre 
Published: July 2016

ABSTRACT:In 1971, Andermann and Andermann described an autosomal recessive syndrome found within the Charlevoix and the Saguenay populations (Quebec, Canada) characterized by agenesis of the corpus callosum (ACC) associated with motor and sensory neuropathy, mental retardation and dysmorphic features. A study of CT in 64 patients demonstrated a total ACC in 37 cases (57.8%), partial ACC in 6 cases (9.4%) and the presence of the corpus callosum in 21 cases (32.8%). The latter was confirmed by MRI in 3 cases. CT of patients without ACC revealed a high frequency of developmental or degenerative midline anomalies, particularly interhemispheric fissure enlargement and posterior fossa atrophy. The clinical presentation and the natural course of the neuropathy, the intellectual impairment and the behavioural manifestations are identical amongst individuals with or without ACC. Individuals with or without ACC are found within the same family and often within the same sibship. These observations support the hypothesis of a single genetic syndrome in which the constant manifestation is the motor and sensory neuropathy.
Coordination of a Multi-Joint Movement in Normal Humans and in Patients with Cerebellar Dysfunction
Authors: Becker W.J. , Kunesch E. , Freund H.-J. 
Published: July 2016

ABSTRACT:The contribution of the cerebellar cortex to coordination of a multi-joint throwing movement was studied by measuring various movement and EMG parameters while normal control subjects and patients with cerebellar cortical atrophy threw a ball at a target. Although patients did not throw as accurately as controls, several coordination measurements were normal in the patients. These included parameters used by us to assess elbow-wrist coordination and the coordination of hand opening with activation of more proximal arm muscles. Postural support for the movement at the shoulder was also normal in that the shoulder was not pushed backwards by the reaction forces resulting from the rapid forward acceleration of the forearm and hand. In contrast, however, patients were unable to coordinate the muscles so as to produce the same hand direction from trial to trial when throwing at the same target. In addition, EMG onset times were abnormal in the antagonist muscles relative to agonist EMG bursts and kinematic parameters of the movement. In conclusion, our patients with cerebellar cortical atrophy showed abnormalities in visual-motor coordination, in that they were unable to consistently produce the appropriate hand direction in response to a visual target. Agonist-antagonist relationships were also impaired. Other aspects of coordination, such as the relative timing of EMG onsets of agonist muscles, even when these were active at different joints, were normal.
Parkinsonism with Neuroacanthocytosis
Authors: Peppard R.F. , Lu C.S. , Chu Nai-Shin , Teal P. , Martin W.R.W. , Calne D.B. 
Published: July 2016

ABSTRACT:Two patients with neuroacanthocytosis are described. One presented with parkinsonism and the other resembled diurnal dystonia of the Segawa type. Both patients responded well to dopaminomimetic therapy. A PET scan with fluorodopa revealed a nigrostriatal deficit in the first patient.
Paraneoplastic Encephalomyelitis and Subacute Dysautonomia due to an Occult Atypical Carcinoid Tumour of the Lung
Authors: Veilleux M. , Bernier J.P. , Lamarche J.B. 
Published: July 2016

ABSTRACT:A case of paraneoplastic encephalomyelitis and subacute pandysautonomia associated with an occult atypical carcinoid tumour of the lung is described. The main clinical features were lethargy, impaired memory, constipation, and orthostatic hypotension. Neurological investigation was unremarkable except for mononuclear pleocytosis and increased protein level in the cerebrospinal fluid (CSF). Tests of autonomic function revealed a low plasma norepinephrine level, a marked drop of blood pressure (BP) to vertical tilt and Valsalva maneuver, and a marked rise of BP to dilute norepinephrine infusion. A few days prior to death, the patient became hypothermic and had repeated episodes of respiratory arrest associated with transient atrioventricular block on the electrocardiogram (ECG). A polysomnography study confirmed a sleep apnea syndrome. Autopsy revealed an atypical carcinoid tumour in one tracheobronchial lymph node, widespread lymphocytic infiltrates and loss of neurones in the cerebral, cerebellar and brainstem gray matter, the spinal cord and roots, and the paravertebral sympathetic ganglia as well as microglial and astrocytic proliferation in the central nervous system.
Fatal Streptokinase-Induced Intracerebral Haemorrhage in Cerebral Amyloid Angiopathy
Authors: Ramsay D.A. , Penswick J.L. , Robertson D.M. 
Published: July 2016

ABSTRACT:A fatal intracerebral haemorrhage (ICH) associated with streptokinase (SK) treatment of an acute myocardial infarction is described. Autopsy examination showed a lobar ICH and severe cerebral amyloid angiopathy (CAA). The close temporal relationship between SK administration and intracranial haemorrhage, the absence of pretreatment risk factors for ICH, and the presence of CAA suggests that these are related phenomena. Accordingly: 1. There may be a synergistic relationship between CAA and intracranial haemorrhage induced by fibrinolytic agents; 2. Thrombolytic agents may induce more frequent than expected intracranial haemorrhage in conditions associated with a high incidence of CAA, notably old age and Alzheimer's disease; 3. A regional defect in haemostasis other than vessel fragility may contribute to the intracranial haemorrhagic predisposition of CAA; 4. Autopsy examination of cases of ICH is an essential part of the audit of clinical trials of fibrinolytic agents.
Multiple Sclerosis in French Canadians: Evidence for HLA Class II Susceptibility and Resistance Genes
Authors: Haegert D.G. , Michaud M. , Francis G.S. 
Published: July 2016

ABSTRACT:HLA class II DRBI, DQB1 and DQA1 gene probes were used to study DNA from unrelated French Canadian multiple sclerosis (MS) patients and controls by restriction fragment length polymorphism (RFLP) analysis. An MS-associated and linked series of allele-specific RFLPs or allogenotypes was identified among this relatively homogeneous ethnic group; the allogenotypes include DRwl5, DQw6 and a DQA1 allogenotype termed DQαlb. An additional allogenotype which cross-hybridizes with DQA1 and is termed DQA2 upper (DQA2U), was shown not only to be part of the MS-associated extended haplotype, but also to be independently associated with MS in DRwl5-negative patients. Conversely a second DQA2 allogenotype, termed DQA2 lower (DQA2L) and a DQB1 allogenotype (DQw7) linked to DQA2L showed negative correlations with MS. It seems likely that the relationship of the HLA class II gene region to MS is complex and that MS susceptibility may reflect interaction between disease susceptibility and resistance genes.
The Mechanism of Embolic Watershed Infarction: Experimental Studies
Authors: Pollanen M.S. , Deck J.H.N. 
Published: July 2016

ABSTRACT:The mechanism for the preferential distribution of emboli to cerebral arterial bordcrzone regions, known to cause some watershed infarcts was studied. We hypothesized that emboli of a specific size range are selectively directed to the arterial borderzones due to the tendency of emboli to bypass the small arterial branches which emerge proximal to major borderzones. To test this hypothesis we perfused the brains of cadavers with suspensions of 90-210 µm glass microspheres and chemically extracted the particles from various arterial territories and a watershed zone. Particles in the 150-210 µm size range were found to be preferentially distributed to the watershed zone whereas particles less than 150 µm in size were randomly dispersed in leptomeningeal arteries of all vascular regions. To assess the role of branch size on the concentration of emboli at bifurcations, we perfused artificial analogs of evenly and unevenly branching bifurcations with suspensions of 90-150 µm and 150-210 µm particles. Branching cylinders with symmetrical branches contained the same concentration of particles, independent of particle size. In contrast, when one branch was one-quarter the size of the other, the concentration of 150-210 µm particles in the asymmetric branch was approximately 65% of the main trunk. Particles 90-150 µm in size were evenly distributed despite variation in branch size. These results indicate that emboli, of a limited range of size, may be selectively propagated to the distal ramifications of subarachnoid arteries located in the watershed zone rather than diverging into small calibre branches which arise along the way.
Similarities of Guamanian ALS/PD to Post-Encephalitic Parkinsonism/ALS: Possible Viral Cause
Authors: Hudson Arthur J. , Rice George P.A. 
Published: July 2016

ABSTRACT:Guamanian amyotrophic lateral sclerosis with parkinsonism-dementia (ALS/PD) has been the subject of intensive study since its discovery in 1947 because of its extraordinarily high incidence in a small ethnic group (Chamorros) whose dietary lack and customs have suggested possible causes. As yet, these and other suspected causes have eluded proof. Because of marked similarities between Guamanian ALS/PD and late onset post-encephalitic (encephalitis lethargica) parkinsonism and ALS it is suggested that they have a common cause. The parkinsonism and ALS in the two disorders are clinically very similar and neuropathological studies have shown a very similar distribution of neurofibrillary tangles in neurons. Some clinical differences, such as ocular features in the post-encephalitic cases and dementia in Guamanian ALS/PD, can be explained by differences in the severity of infection and the interval between the encephalitis and onset of sequelae. Although unproven, influenza A (HswilNl strain) has long been suspected as the cause of encephalitis lethargica because of simultaneous pandemics of the two diseases in the 1920s. Because influenza A can persistently infect cells and has a marked propensity to mutate it is an optimal candidate among other RNA viruses for delayed nervous system infection as a possible cause of ALS/PD.
1990 Richardson Lecture — Challenges for Neurology in the Nineties: Will We Survive?
Authors: Martin Joseph B. 
Published: July 2016

It is a great honor for me to present the Richardson Lecture this year. Although I was not personally acquainted with Dr. Richardson, his contributions to Canadian neurology are legendary, not the least of which is immortalized in the disease he and his colleagues first described in 1964: Steele-Richardson-Olszewski syndrome.I have entitled my talk “Challenges for Neurology in the 90s: Will We Survive?”, to highlight some of the issues that I believe are important for us to consider as we embark upon our academic enterprise during the last decade of the 20th century. There are a number of opportunities as well as, potentially, major difficulties that we face, and I wish to focus attention on some of them.
MPTP-Induced Neurotoxicity and the Quest for a Preventative Therapy for Parkinson's Disease
Authors: Furtado J.C.S. , Mazurek Michael F. 
Published: July 2016

ABSTRACT:Less than 10 years have passed since the discovery that 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is capable of producing parkinsonism in both humans and non-human primates. In that time, there has been considerable interest in the possibility that the pathogenesis of idiopathic Parkinson's disease (PD) might involve a process analogous to that of MPTP toxicity. One hypothesis holds that PD might arise, at least in part, from exposure to an MPTP-like environmental toxin. Rapid progress has been made towards elucidating the precise mechanism by which MPTP exerts toxicity, and clarifying the relationship of MPTP toxicity to idiopathic PD. The goal of these efforts is to develop a therapy that inhibits the underlying disease process in PD.