bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brachytherapy for Recurrent Single Brain Metastasis
Authors: Bernstein Mark , Cabantog Alberto , Laperriere Normand , Leung Phil , Thomason Cindy 
Published: February 2016

ABSTRACT:Of 112 stereotactic high-activity iodine-125 implants for malignant brain tumors done as of July 1, 1994, ten have been done for recurrent single brain metastasis and constitute the study group described herein. All patients had initially undergone craniotomy for tumor resection followed by fractionated external beam whole brain radiation and recurred at the same site in the brain. The interval between initial cancer therapy and occurrence of the brain metastasis was 13 – 156 weeks (median: 63 weeks). The interval between initial treatment of the brain metastasis and its recurrence treated with brachytherapy was 13-69 weeks (median: 35 weeks). Minimum brachytherapy dose administered was 70 Gy at a median dose rate of 67 cGy/hour. Eight- patients have died. Two died suddenly at 2 and 13 weeks post-implant of presumed pulmonary embolus. Five died of recurrence of the brain metastasis at 20, 39, 52, 103, and 143 weeks post-implant, and one died of systemic metastases at 40 weeks post-implant. Two patients remain alive 183 and 324 weeks post-implant. High-activity iodine-125 brachytherapy appears to be of benefit for selected patients with recurrent single brain metastasis but larger, and preferably randomized studies are needed.
Surgery of Unruptured, Asymptomatic Aneurysms: a Decision Analysis
Authors: Leblanc Richard , Worsley Keith J. 
Published: February 2016

ABSTRACT:Background: Asymptomatic cerebral aneurysms are diagnosed more frequently since the advent of computed tomography and magnetic resonance imaging. Their management is currently empirical. We have used decision analysis to place it on a more analytical basis. Methods: Decision analysis was used to determine the benefit in years of survival free of sequelae resulting from elective surgery of unruptured aneurysms over natural history. We took 2% as the annual rate of rupture (r), 73% as the risk of death or disability with rupture (M), and 6.5% for the average risk of elective surgery (S). Benefit was calculated from the equation L{[1-(1-r)L]M/2-S} [1] for life expectancy (L) corresponding to each quinquennial age group from age 15 to 100 years. Sensitivity analysis was performed to take into account increasing risk of elective surgery based on the size, and accessibility of the aneurysm, and variable risks of rupture and outcome. Results: A gain of at least one year of survival free of neurological sequelae is achieved by surgery compared to natural history for patients whose life expectancy is 19.5 years, corresponding to age 63.5 years for males and 68 years for females. The life expectancy at which a benefit accrues is longer (the patient is younger) for larger, less accessible aneurysms, for lower rates of rupture, and for lesser risks of death or disability from rupture. Conclusions: Elective surgery of unruptured asymptomatic aneurysms achieves an increased survival over the natural history of at least one year free of neurological sequelae in patients whose life expectancy is 19.5 years or more, using our baseline assumptions. Using equation [1], the corresponding life expectancy producing this benefit can be calculated to account for the increased surgical risk of large, poorly accessible aneurysms and for factors affecting natural history.
Sensorimotor Neuropathy and Abnormal Vitamin B12 Metabolism in Early HIV Infection
Authors: Veilleux M. , Paltiel O. , Falutz J. 
Published: February 2016

ABSTRACT:Distal sensory peripheral neuropathy (DSPN) has been reported in 5 to 75% of patients with human immunodeficiency virus (HIV) infection, particularly in advanced stages of the disease. Twenty HIV seropositive patients were studied prospectively to determine the frequency of DSPN in clinical stage II and III of the HIV infection, and to investigate the role of vitamin B12 deficiency on the frequency of DSPN in HIV patients. All patients had complete blood count, serum vitamin B12 level, anti-intrinsic factor antibody, Schilling test, and electrodiagnostic studies including nerve conduction studies and concentric needle examination in the lower extremities, and sympathetic skin responses. Only 1 patient (5%) had clinical and electrophysiological evidence of possible DSPN. Of the 6 patients with abnormal Schilling test, only one had DSPN based on distal sensory symptoms, abnormal neurological examination and electrodiagnostic studies. Evidence for possible DSPN was present in 5% of patients with early HIV infection and did not appear to be more frequent in patients with concurrent vitamin B12 deficiency.
Spinal Somatosensory Evoked Potentials in Patients with Tethered Cord Syndrome
Authors: Polo Alberto , Zanette Giampietro , Manganotti Paolo , Bertolasi Laura , Grandis Domenico De , Rizzuto Nicolo’ 
Published: February 2016

Abstract:We studied the electrophysiological changes occurring in six patients with tethered cord syndrome. Evidence of spinal malformations was provided by magnetic resonance imaging. The functional assessment of the spinal cord was performed by analysing both spinal and cortical somatosensory evoked potentials. The evoked electrospinogram was recorded from the thoracic and lumbosacral spinous processes. The N22 lumbosacral potential was selectively affected, being rostrocaudally displaced and reduced in amplitude or even absent in patients with neurological signs indicating a segmental lower cord lesion. Inter-peak somatosensory evoked potentials latency was normal in all cases, suggesting that ascending axonal potentials in the dorsal column fibres may be synchronized. Segmental potentials of the lumbosacral response, originating from the post-synaptic activity of dorsal horn interneurons, are selectively affected in this syndrome resulting from the rostrocaudal displacement of the spinal cord due to tethering. Our findings in the clinical field are consistent with previous experimental evidence indicating a different sensitivity of the gray vs. white matter to progressive stretching.
Progression and Outcome of Patients in a Canadian Dementia Clinic
Authors: Hogan David B. , Thierer Daniel E. , Ebly Erika M. , Parhad Irma M. 
Published: February 2016

Abstract:Five hundred and fifty-three patients were referred to a Canadian dementia clinic for standardized evaluation. The majority (83.5%) had a dementia with Alzheimer’s disease (AD) accounting for 89% of dementias. Patients with probable AD who were followed for five years had variable rates of progression, increased mortality (37.1%, 2.5 times the expected rate) and a high rate of institutionalization (79%). Simple demographic (age) and social factors (marital status) were strong predictors for institutionalization. It was extremely difficult at presentation to predict the rate of progression. The prevalence of AD in autopsied cases was 62.5%. Clinic patients were younger, had milder dementias, and were more likely to have AD than patients identified in the course of a contemporaneous population-based dementia prevalence study.
Diagnosis of Vascular Dementia: Consortium of Canadian Centres for Clinical Cognitive Research Concensus Statement
Authors: Rockwood Kenneth , Parhad Irma , Hachinski Vladimir , Erkinjuntti Timo , Rewcastle Barry , Kertesz Andrew , Eastwood M. Robin , Phillips Stephen 
Published: February 2016

Abstract:Interest in vascular causes for cognitive impairment is increasing, in recognition that such causes are common, and possibly preventable. This has led to attempts to better define vascular dementia and its natural history. Several sets of criteria for the diagnosis of vascular dementia have been proposed. We provide a brief overview of the background to the initiation of a Canadian consensus conference, established by the Consortium of Canadian Centres for Clinical Cognitive Research (C5R) and report the conclusions reached at that conference. To date, no one set of criteria is demonstrably superior to another; we have therefore not endorsed any of the competing sets, nor have we recommended our own. Instead we suggest that empiric studies are required to establish valid criteria. A diagnostic checklist, which combines existing criteria and additional data, is attached for clinicians wishing to participate in such studies.
Ataxia in Institutionalized Patients with Epilepsy
Authors: Young G.B. , Oppenheimer S.R. , Gordon B.A. , Wells G.A. , Assis L.P.A. , Kreeft J.H. , Lohuis N.A. , Blume W.T. 
Published: February 2016

Abstract:Fifty-four per cent of 41 chronically institutionalized adult patients with epilepsy had ataxia of gait (wide mean stride width). None of the following correlated with stride width: serum phenytoin, previous phenytoin toxicity, seizure frequency, or status epilepticus. Seventeen of the 41 patients had computed tomographic head scans. Patients with radiological evidence of cerebellar atrophy had a wider mean stride width, later age of onset of seizures, greater peak serum concentrations of phenytoin than did those without cerebellar atrophy. Ataxia of gait was inconsistently associated with cerebellar atrophy. Elevated serum/plasma concentrations of phenytoin may be a risk factor for cerebellar atrophy, but seizure frequency or status epilepticus are not independently related to this complication.
Detection of Lewy Bodies in Trisomy 21 (Down's Syndrome)
Authors: Raghavan Ravi , Khin-Nu Clare , Brown Andrew , Irving Dorothy , Ince Paul G. , Day Kenneth , Tyrer Stephen P. , Perry Robert H. 
Published: February 2016

ABSTRACT:The presence of cortical senile plaques and neurofibrillary tangles sufficient to warrant a neuropatho-logical diagnosis of Alzheimer's disease is well established in middle-aged individuals with Trisomy 21 (Down's syndrome). In contrast a relationship between Down's syndrome and Lewy bodies, one of the major neuropathological features of Parkinson's disease, has not been previously reported. In a cliniconeuropathological survey of 23 cases of Down's Syndrome, two patients, aged 50 and 56 years respectively, were found to have Lewy body formation in the substantia nigra in addition to cortical Alzheimer-type pathology. Neither case showed significant substantia nigra neuron loss although locus coeruleus loss was present in both. Since substantia nigra Lewy bodies are a characteristic neu-rohistological feature of idiopathic Parkinson's disease, their occurrence in cases of Down's syndrome with evidence of Alzheimer-type pathology supports an aetiopathological connection between Parkinson's disease, Alzheimer's disease, and Down's syndrome; and suggests that common pathogenic mechanisms may underlie aspects of neuronal degeneration in these three disorders, some of which may relate to aberrant chromosome 21 expression.
CSF Shunt Infections: A Fifteen-Year Experience with Emphasis on Management and Outcome
Authors: Morissette Isabelle , Gourdeau Marie , Francoeur Jacques 
Published: February 2016

ABSTRACT:A retrospective study of patients with cerebrospinal fluid shunt infections was undertaken from 1975 to 1989 in a university hospital. The data were analyzed with emphasis on the choice of treatment and outcome. There were 44 infectious episodes in 38 patients for an overall rate of 2.6%, including 30 ventriculoperitoneal, 11 ventriculoatrial and 3 lumboperitoneal shunts. The most frequently isolated pathogens were staphylococci in 61% of the cases followed by gram-negative bacilli in 25%. Different modalities of treatment were used: support (2), intravenous antibiotics alone (6), intravenous antibiotics and shunt revision (3), intravenous antibiotics and shunt removal with or without prior externalization of the distal end (33: 13 + 20). The cure rate was 94% (31/33) with this last modality of treatment. Only 3 patients received intraventricular antibiotics. All deaths occurred in patients treated with support only (2) or with antibiotics alone (1). Four of the six recurrent episodes occurred in patients treated with antibiotics alone (2) or with a shunt revision (2). We conclude that carefully chosen intravenous antibiotics combined with shunt removal preceded or not by externalization of the distal end as an alternative therapy to repeated ventricular taps or insertion of an external ventricular drainage device is an appropriate therapy.
Cerebral Vein Thrombosis due to Hereditary Antithrombin III Deficiency
Authors: Tuite Paul , Ahmad Ferhaan , Grant Ian , Stewart John D. , Carpenter Stirling , Ethier Romeo 
Published: February 2016

ABSTRACT:Cerebral vein thrombosis, also called superior sagittal sinus thrombosis, is a well recognized clinical and radiologic entity associated with a variety of medical disorders. We report a patient with fatal cerebral vein thrombosis following myelography, in whom the cause was familial antithrombin III (AT3) deficiency. Unsuspected AT3 deficiency should be considered in cases of unexplained cerebral venous thromboses.
Reflex Responses in Upper Limb Muscles to Cutaneous Stimuli
Authors: Chen R. 
Published: February 2016

ABSTRACT:Cutaneous reflexes in the upper limb were elicited by stimulating digital nerves and recorded by averaging rectified EMG from proximal and distal upper limb muscles during voluntary contraction. Distal muscles often showed a triphasic response: an inhibition with onset about 50 ms (Il) followed by a facilitation with onset about 60 ms (E2) followed by another inhibition with onset about 80 ms (12). Proximal muscles generally showed biphasic responses beginning with facilitation or inhibition with onset at about 40 ms. Normal ranges for the amplitude of these components were established from recordings on 22 arms of 11 healthy subjects. An attempt was made to determine the alterent fibers responsible for the various components by varying the stimulus intensity, by causing ischemic block of larger fibers and by estimating the afferent conduction velocities. The central pathways mediating these reflexes were examined by estimating central delays and by studying patients with focal lesions
Geographic Variations in the Prevalence Rates of Parkinson’s Disease in Alberta
Authors: Lawrence W. Svenson , Howard Platt G. , Sheena E. Woodhead 
Published: February 2016

ABSTRACT:Parkinson’s disease prevalence rates were examined for the Province of Alberta by age, sex and census division. Using the claims administrative data from the Alberta Health Care Insurance Plan, a cohort of all registered individuals (2.4 million) was extracted and followed for the five year period, April 1, 1984 to March 31, 1989. No new members were added to the cohort and an attrition rate averaging 6% per year was observed. The overall crude prevalence rates of 248.9 and 239.8 per 100,000 population were noted for males and females respectively. Both sexes were found to have a statistically significant variation across Alberta’s 19 census divisions. For males, examination of standardized morbidity ratios found a low risk of Parkinson’s disease associated with five census divisions, of which two contained Alberta’s two largest cities. An excess risk was associated with four primarily rural census divisions. Females, on the other hand, had a low risk associated with one rural census division and excess risk in four census divisions. The uneven distribution within Alberta offers support for an environmental theory of etiology which may be associated with rural living.
The Differential Diagnosis of Adult Onset Metachromatic Leukodystrophy and Early Onset Familial Alzheimer Disease in an Alzheimer Clinic Population
Authors: Sadovnick A.D. , Tuokko H. , Applegarth D.A. , Toone J.R. , Haijistavropoulos T. , Beattie B.L. 
Published: February 2016

ABSTRACT:Clinical differentiation between forms of progressive dementia can prove difficult, particularly when relatively rare forms of dementia are involved. Factors such as family history of dementia, age at onset, presenting features such as personality change, cognitive deficits, psychiatric symptoms, and clinical course (progressive deterioration; retention of skills over time) may prove useful for directing investigations to identify underlying pathology and genetic implications. This is illustrated by two patient reports. Each patient had the onset of memory/behavioral problems at approximately age 40 years, was initially given a psychiatric, non-dementing diagnosis, and had a positive family history for early onset behavioral and memory problems. After longitudinal assessment, the diagnosis of Alzheimer disease was confirmed at autopsy in one patient and a diagnosis of familial, adult-onset metachromatic leukodystrophy in the other.
Real Time Operations of the Cerebellar Cortex
Authors: James R. Bloedel , Vlastislav Bracha , Paul S. Larson 
Published: February 2016

ABSTRACT:This manuscript reviews a series of experiments which support the notion that the cerebellum and more specifically the cerebellar cortex is principally involved in real time operations required for the regulation of coordinated motor activity. Experiments are reviewed which illustrate: (1) that the climbing fiber inputs to Purkinje cells can induce a short-lasting enhancement of their responses to mossy fiber-granule cell-parallel fiber inputs, (2) that the cerebellum is not essential for the acquisition and performance of the classically conditioned nictitating membrane reflex (NMR) of the rabbit, and (3) that the observations resulting from the microinjection of lidocaine and multiple single unit recordings within the brainstem support the notion that cell populations in this region may participate in establishing the modifications in neuronal interactions required for the acquisition of the conditioned NMR. In addition, preliminary data are shown comparing the capacity of a normal subject and a patient with a massive ipsilateral cerebellar stroke to learn certain tracing tasks and to redraw these learned tracing movements 90° to the orientation of the original image. The data support the notion that the cerebellum is essential, not for the initial learning of the tracing movement, but rather for performing the learned movement with the required rotation of the original image.
Comparing Cerebellar and Motor Cortical Activity in Reaching and Grasping
Authors: Allan M. Smith , Clause Dugas , Pierre Fortier , John Kalasha , Nathalie Picard 
Published: February 2016

ABSTRACT:The activity of single cells in the cerebellar and motor cortex of awake monkeys was recorded during separate studies of whole-arm reaching movements and during the application of force-pulse perturbations to handheld objects. Two general observations about the contribution of the cerebellum to the control of movement emerge from the data. The first, derived from the study of whole arm reaching, suggests that although both the motor cortex and cerebellum generate a signal related to movement direction, the cerebellar signal is less precise and varies from trial to trial even when the movement kinematics remain unchanged. The second observation, derived from the study of predictable perturbations of a hand-held object, indicates that cerebellar cortical neurons better reflect preparatory motor strategies formed from the anticipation of cutaneous and proprioceptive stimuli acquired by previous experience. In spite of strong relations to grip force and receptive fields stimulated by preparatory grip forces increase, the neurons of the percentral motor cortex showed very little anticipatory activity compared with either the premotor areas or the cerebellum.
Synaptic Plasticity in the Cerebellar Cortex and its Role in Motor Learning
Authors: Masao Ito 
Published: February 2016

ABSTRACT:Synaptic plasticity plays a role in the learning capability of brain tissues. Long-term depression (LTD) of parallel fiber synapses in cerebellar Purkinje cells occurs when these synapses are activated in conjunction with climbing fiber synapses. Signal transduction mechanisms underlying LTD have recently been investigated extensively. It has also become apparent that climbing fiber signals encode errors in the motor performance of an animal. It is therefore hypothesized that learning proceeds in cerebellar tissues in such a way that error signals of climbing fibers act to depress by LTD those parallel fiber synapses responsible for the errors. The cerebellum contains a large number of corticonuclear microcomplexes. Each microcomplex is connected to an extracerebellar system and is presumed to endow the system with learning capability. The hypothesis accounts for the adaptation of the vestibuloocular reflex and probably also for other forms of motor and cognitive learning.
Partition of the Human Cerebellum in Sensory-Motor Activities, Learning and Cognition
Authors: Roland P.E. 
Published: February 2016

ABSTRACT:The circuitry of the cerebellum is quite well understood. The computation takes place in the cerebellar cortex, which functions in synchronized strips to provide excellent timing signals to the cerebral cortex and the spinal cord. The cerebellar cortex is also the site where error signals from other parts of the central nervous system are incorporated. For voluntary limb movements the cerebellular cortex is important for the timing of the innervation of the agonist and antagonist anterior horn neurons. It is also important for the temporal order of and precision in the execution of motor programs. As will be apparent, the cerebellum is not only a computer taking care of motor programs.
The Cerebellar Serotoninergic System and its Possible Involvement in Cerebellar Ataxia
Authors: Trouillas P. 
Published: February 2016

ABSTRACT:A review concerning the characteristics of the cerebellar serotoninergic system is presented. In rat, cat and oppossum, the perikarya of origin are located in the brain stem raphe nuclei and in other brainstem structures. The projections to the cerebellar layers and deep nuclei include synaptic connections, but also non synaptic terminals, espedaily in a diffuse cortical plexus. Serotoninergic receptors have been described: 5-HT1B in the molecular layer and 5-HT2 in the inferior olive. Serotonin exerts neurophysiological effects on several target cells, directly or indirectly, presynaptically or postsynaptically. A modulatory effect on Purkinje cells is well documented. In thiamine deprived animals, a specific serotoninergic cerebellar syndrome includes a selective degeneration of the serotoninergic cerebellar system, an increase of the 5-HIAA cerebellar values and an exaggerated serotoninergic turnover. In human here-doataxias (Friedreich’s ataxia and cerebellar cortical atrophy), serotoninergic disturbances have been observed in the CSF, including low 5-HIAA values and an increased serotoninergic turnover. Therapeutic results have been obtained with L-5-HTP, a precursor of serotonin, in several conditions presenting cerebellar ataxia. L-5-HTP resistance of olivo-pontocerebellar atrophies may be explained by the destruction of serotonin-sensitive target cells, especially Purkinje cells.
Physiologic Studies of Dysmetria in Patients with Cerebellar Deficits
Authors: Mark Hallet , Steve G. Massaquoi 
Published: February 2016

ABSTRACT:A feature of cerebellar ataxia is dysmetria, which is characterized by inaccurate movements. Studies of rapid movements at a single joint show prolonged acceleration phases and prolonged initial bursts of EMG activity in the agonist muscle. These two features correlate with each other, suggesting that the prolongation of the neural signal is responsible for the kinematic abnormality. This explains a tendency to hypermetria. Studies of multijoint movements show abnormalities in relative timing of the different joints. During locomotion, knee and ankle motions can be delayed differentially with respect to the gait cycle. Subjects attempting straight-line movements with the arm have systematic deviations that reflect incoordination of the shoulder and elbow with respect to each other. A possible explanation of dysmetria is a failure of sufficient force generation within the necessary time to accomplish a coordinated movement. Another possible explanation is that the cerebellum is responsible for timing of brain functions.