bluuebunny/crossref_metadata_2025 huggingface dataset:
The Course of Post-Traumatic Amnesia: Three Little Words
Authors: Schwartz M.L. , Carruth F. , Binns M.A. , Brandys C. , Moulton R. , Snow W.G. , Stuss D.T.
Published: February 2016

Objective:

To provide a simple means of ”real time“ recognition of emergence from post-traumatic amnesia (PTA).

Methods:

Ninety-one patients with traumatic brain injury (PBI); 53 minor (GCS 13-15), 19 moderate (GCS 9-12), 18 severe (GCS 3-8). Twenty-seven control subjects treated at two regional trauma units for their acute phase and followed in a hospital-based research institute were studied prospectively. Subjects were examined repeatedly following injury with the Galveston Orientation and Amnesia Test (GOAT) and tests of their ability to learn and retain new information. Word triplets balanced for concreteness and frequency were presented. Immediate and 24-hour recall were tested. If 24-hour recall was imperfect, recognition was tested by presenting the 3 target words and 6 distracters. The target words were then re-presented and recall was tested the next day. The time intervals to first perfect recognition and first free perfect recall were compared with the patients' first GOAT score of 75 or greater on 2 successive days. Simple line drawings of common objects were also presented to the subjects using an identical paradigm. The outcome measures were GOAT, 3-word recognition and recall, 3 picture recognition and recall.

Results:

For all categories of head injury severity, the median interval to perfect free recall of words followed the achievement GOAT criterion by a significant interval. The mean GOAT scores for perfect 3-word recall and recognition corresponding to minor, moderate and severe injuries were 97, 90 and 88, and 97, 76 and 68 respectively. The recognition and recall of pictures preceded the recognition and recall of words by approximately 1 day.

Conclusions:

The orientation measures of the GOAT that contain material that the patient knew prior to injury obscure the determination of recovery of continuous memory and should be tested separately. Three-word recall which is simpler to administer than the GOAT is a more reliable measure of emergence from PTA. For patients who are dysphasic or who do not share a common language with the examiner, 3-picture recognition and recall may substitute for word recognition and recall.
Cost Analysis of Methylprednisolone Treatment of Multiple Sclerosis Patients
Authors: Robson Lynda S. , Bain Charlene , Beck Shann , Guthrie Suzanne , Coyte Peter C. , O'Connor Paul
Published: February 2016

Background:

Intravenous methylprednisolone (IVMP) is the treatment of choice for multiple sclerosis (MS) patients undergoing acute exacerbation of disease symptoms and yet its cost has not been accurately determined. Determination of this cost in different settings is also pertinent to consideration of cost-saving alternatives to in-patient treatment.

Methods:

Cost analysis from the point of view of the health care system of IVMP treatment of MS patients receiving treatment in association with a selected Toronto teaching hospital in fiscal year 1994/95 was carried out. Costs of any concurrent treatments were excluded.

Results:

Total cost for 92 patients, based on a 4 dose regime, was estimated to be $78,527. The the cost per patient was $1,1181.84 for in-patients (IP), $714.64 for out-patients of the MS Clinic (OP) and $774.21 for patients whose treatment was initiated in the Clinic, but completed in the home (HC). Sensitivity analyses indicated: 1) IP treatment was in all cases more expensive than that of OP or HC; 2) the cost savings of OP vs. HC was sensitive to assumptions made regarding Clinic overhead, Clinic nursing costs and Home Care Program overhead.

Conclusion:

Alternatives to in-patient care must be considered carefully. In this study, both out-patient and in-home treatment were cost-saving alternatives to in-patient treatment, but large differences in the cost of hospital out-patient vs. in-home care could not be demonstrated.
Pathological Laughter Following Intravenous Sodium Valproate
Authors: Jacob P.C. , Pratap Chand R.
Published: February 2016

Background:

Pathological laughter can be a sign of epilepsy, psychiatric illness, effect of toxins or psychotropic drugs or of structural brain disease.

Method:

Case Studies.

Result:

Two patients developed inappropriate uncontrollable laughter following intravenous sodium valproate for treatment of epilepsy.

Conclusion:

Pathological laughter can be a side effect of intravenous sodium valproate.
Electrophysiological Respiratory Studies in the Critical Care Unit
Authors: Zifko Udo A.
Published: February 2016

Respiratory electrophysiological studies are useful in the investigation and monitoring of respiratory failure. Phrenic nerve conduction studies and needle electromyography of the diaphragm are invaluable in establishing the diagnosis, determining the severity, and following the progression of peripheral respiratory muscle dysfunction. In addition to these established methods, repetitive phrenic nerve stimulation is of diagnostic value in patients with neuromuscular transmission defects and dyspnea. The diagnosis of impaired central respiratory drive can often be accomplished by the newly-developed techniques of transcortical magnetic stimulation of the motor cortex with recording of the diaphragm and phrenic nerve somatosensory evoked potentials. These studies are of particular value in critically ill patients where both the central and peripheral lesions may impair respiration.
Methods of Testing Neuromuscular Transmission in the Intensive Care Unit
Authors: Grand'Maison François
Published: February 2016

All disorders of neuromuscular transmission (NMT) may cause ventilatory failure, albeit rarely. Respiratory muscle weakness is occasionally the presenting feature of myasthenia gravis (MG), the Lambert-Eaton myasthenic syndrome (LEMS), hypermagnesemia and botulism. Chronic MG, congenital myasthenic syndromes and LEMS may be acutely exacerbated by various intercurrent conditions and by drugs which interfere with NMT. Finally, in the ICU, difficulty in weaning from the ventilator may be caused by prolonged use of neuromuscular blocking agents. Electrophysiological studies of NMT disorders in the intensive care unit have rarely been reported. Nevertheless, the available data indicates that the electrodiagnosis of severe NMT disorders can be misleading. With severe NMT defects, the electrophysiological distinction between post-synaptic and pre-synaptic disorders is blurred and the differential diagnosis with myopathies may be difficult. A clinically suspected NMT disorder should therefore not be ruled out when electrodiagnosis fails to demonstrate the expected abnormalities.
Myopathies in the Intensive Care Unit
Authors: Zochodne Douglas
Published: February 2016

Myopathies that occur in the intensive care unit can be divided into preexisting myopathies or newly acquired myopathies that develop in the intensive care unit. Myotonic dystrophy is an example of a preexisting myopathy that may render patients susceptible to acute respiratory failure following surgical procedures and anaesthesia. A group of myopathies that develop within the intensive care unit have been labelled acute necrotizing myopathy of intensive care, thick filament myopathy and acute steroid myopathy. Corticosteroids and nondepolarizing muscle blocking agents may play a role in their development.
Descriptive Epidemiology of Parkinson’s Disease through Proxy Measures
Authors: Strickland Daniel , Bertoni John M. , Pfeiffer Ronald F.
Published: February 2016

Background and Objective: In preparation for analytic study we undertook to describe areas of relative excess and deficit of Parkinson’s Disease (PD) in Nebraska and tested two methodologic tools for inexpensive assessment of descriptive epidemiology of PD. Methods: In lieu of large-scale population screening and diagnosis, we obtained sales information of anti-PD drugs in the state in 1988 – 1990 as well as listings of all people dying from 1984 to 1993 who had Parkinson’s Disease mentioned anywhere on their death certificate. The anti-PD drug sales data are intended as a proxy for prevalence, while the death certificate data are intended as a proxy for incidence. Results: Sales divided by population over age 54 indicates where anti-PD drug sales differ from expected. We found high correlation of drug sales rates with several farming exposures. Age-adjusted death rates, however, showed a low degree of association with sales or farming variables. This may be attributable to differences in death certificate completion or in underlying incidence versus prevalence. Conclusions: These techniques provide a useful tool for delineating possible differences in incidence and prevalence. While not as accurate as full community survey with expert diagnosis, they are not as expensive, and can be followed by local cluster investigations and individual-level etiologic studies to test hypotheses resulting from the initial study.
Herbert Jasper: an Appreciation and a Tribute on His 90th Birthday
Authors: Andermann Frederick
Published: February 2016

It is particularly fitting that at this reception of members of the Canadian Neurological and Clinical Neurophysiologists Societies at the American Academy of Neurology we should honour Dr. Herbert Jasper. He is, at the age of 90, a living legend in the neurosciences. It is a rare opportunity for the young people who have followed him to meet a pioneer of his generation, let alone somebody who continues to this day to exercise his wise counsel and his extraordinary grasp of the working of the human brain.

Herbert Jasper, like Wilder Penfield, was born in the west of the United States, and, like his friend and colleague, became a Canadian and a founder of Canadian Neuroscience.

Jasper started his career as a psychologist of physiological persuasion and studied with Lapique who is remembered for his studies on chronaxie, in Paris. He became aware of Berger’s writings on the electroencephalogram and realized early the enormous potential of being able to record the electrical activity generated by the human brain. In the 30s, two schools of epilepsy developed in North America: the medical with William Lennox in Boston, and the surgical with Wilder Penfield in Montreal.
Localizing Muscles for Botulinum Toxin Treatment of Focal Hand Dystonia
Authors: Geenen C. , Consky E. , Ashby P.
Published: February 2016

Background: There is currently no consensus on the best way to localize muscles in the forearm for botulinum toxin (BTX) injection. We devised a study to compare electromyography (EMG) with local stimulation through a cannula for localizing forearm muscles for botulinum toxin (BTX) injection, and for predicting the risk of unwanted weakness in non-target muscles. Methods: In 12 patients with focal hand dystonia a single “target” muscle, determined by clinical examination to contribute most to the dystonic hand posture, was selected for botulinum toxin injection. The patients were randomized into 2 treatment groups, one in which the target muscle was localized by recording the EMG signals during voluntary contractions (8 patients) and the other in which the target muscle was localized by local electrical stimulation (4 patients). The target muscle was then injected with a standardized dose of BTX. Results: At follow-up 3 weeks after BTX injection the target muscle was weakened in 7/12 patients (4/8 of the EMG group, and 3/4 of the stimulation group). Additional non-injected muscles, adjacent to the target muscle, were weakened in 5 of these 7 patients, presumably from diffusion of the toxin. Conclusions: Localization by stimulation is probably at least as good as EMG. Each technique has certain advantages. Weakness of “non-target” muscles was not consistently predicted by either EMG or stimulation suggesting that BTX diffuses farther than the volume conduction of EMG signals or the spread of effective stimulus current.
Focal Midbrain Glioma: Long Term Survival in a Cohort of 16 Patients and the Implications for Management
Authors: Hamilton Mark G. , Lauryssen Carl , Hagen Neil
Published: February 2016

Background: Focal gliomas involving the midbrain tectum and tegmentum have been identified as having a better prognosis than diffuse tumors affecting the brain stem. However, only limited information is available concerning treatment effectiveness and long term outcome for these patients. Methods: A retrospective, population-based cancer registry survey was performed to assess the clinical features and treatment courses of patients with focal midbrain tumors. Results: Sixteen patients with midbrain gliomas were identified; eight had tectal gliomas and eight tegmental gliomas. Thirteen patients presented with symptoms related to hydrocephalus, and 12 required a ventriculoperitoneal shunt. Seven patients underwent surgery directed at the tumor. Eight patients underwent initial radiation therapy and none had initial chemotherapy. One patient diagnosed at age 18 months had a rapidly growing tumor after 14 months of follow up which has responded to chemotherapy. The mean survival of this patient population was 84 months (range 3-280 months) after diagnosis, with only one tumor related death occurring (280 months after diagnosis). Survival was not affected by tumor location within the midbrain (tegmental or tectal) or by whether radiation therapy was or was not administered. Conclusions: Patients with focal midbrain gliomas require symptom control aimed at treatment of hydrocephalus, or mass effect from the tumor. However the extended survival of this population suggests that routine aggressive surgical debulking is often not required. Furthermore, the routine use of radiation therapy or chemotherapy for all such patients is questioned.
Functional MRI Localization of Language in a 9-Year-Old Child
Authors: Benson R.R. , Logan W.J. , Cosgrove G.R. , Cole A.J. , Jiang H. , LeSueur L.L. , Buchbinder B.R. , Rosen B.R. , Caviness V.S.
Published: February 2016

Background: Localizing critical brain functions such as language in children is difficult and generally requires invasive techniques. Recently sensory, motor and language functions in adults have been mapped to specific brain locations using functional imaging techniques. Of these techniques, functional MRI (fMRI) is the least invasive and has the highest spatial and temporal resolution. Its use in adults is well documented but application to children has not been as well described. In the present study lateralization and localization of language was evaluated with fMRI prior to epilepsy surgery in a nine-year-old male with complex partial seizures, attentional difficulty and decreased verbal proficiency. Methods: Two language paradigms well studied in adults (read, verb generation) and two additional language paradigms (antonym generation, letter fluency) were studied using whole brain fMRI after stimulus items and timing were adjusted to achieve the desired performance level during imaging. The patient was also conditioned to the magnet environment prior to imaging. Results: Word reading and letter fluency tasks produced lateralized and localized activation similar to that seen in adults. The patient had no language deficits following an anterior 2/3 dominant temporal lobe resection. Conclusions: With modifications of protocols such as those detailed in this report, this non-invasive method for localizing language function is feasible for the presurgical evaluation of children as well being applicable for a variety of developmental language issues.
Bilateral Hypoglossal Nerve Injury with Occipital Condylar Fracture
Authors: Lam Cornelius H. , Stratford Joseph
Published: February 2016

Background: A 20-year-old woman with a right occipital condylar fracture and bilateral hypoglossal nerve injury is presented. Only 17 cases of condylar fracture have been reported in the literature. Methods: The patient was evaluated with plain films, coronal and axial cut CT, and MRI. Results: MRI showed a severely distorted but otherwise normal medulla and a displaced condylar bone fragment. Conclusion: Condylar fracture may cause twelfth nerve palsy by injuring the central or peripheral nerve.
Historical Neurology and Neurosurgery George A. Savoy? Visionary Benefactor of Canadians with Epilepsy, and the History of the Savoy Foundation for Epilepsy
Authors: Rémillard C.M. , Zifkin B.G. , Sherwin A. , Feindel W.
Published: February 2016

George A. Savoy was born in Cohoes, New York, in 1873. He left the U.S.A. in 1921 to manage the Canadian branch of a large manufacturer of ledgers and looseleaf registers. This company was asked to supply Professor Jasper’s laboratory with rolls of plain unlined paper and it was George Savoy who later developed fanfolded and lined EEG paper, which was first used at the Montreal Neurological Institute. He also had personal contacts with Wilder Penfield concerning their mutual interest in the needs of patients with epilepsy. He was a successful industrialist involved with several charitable organizations funding programmes for people with epilepsy. He was opposed to the sectarianism then prevalent in Quebec, which was unfamiliar to him, and in reaction built his own institution, Dieppe House, a home for people with epilepsy, later renamed «Foyer Savoy». It was to operate without regard to race, language or religion. In 1971, his son Harold and other generous donors decided to create a foundation to support research in epilepsy. The Foyer Savoy was sold in 1988 and the proceeds used to increase the endowment of the foundation. His grandson George M. Savoy is the current president. The fourth generation is also represented by Caroline Savoy, daughter of the president, who joined the board of directors in 1992. The foundation will distribute from $300,000 to $400,000 yearly to researchers from many different countries working in the field of epilepsy in universities and hospitals throughout Canada.
Protection of the Brain After Aneurysmal Rupture – Richardson Lecture
Authors: Weir Bryce
Published: February 2016

The majority of patients survive the first dangerous hours after an aneurysmal rupture. However, many subsequently succumb as a result of a variety of lethal complications. The most important of these develop as sequelae of the initial ischemia, rebleeding and the delayed onset of vasospasm. Some of these deleterious cascades can be aborted. Since the delayed complications such as vasospastic infarction can be accurately predicted, this is one of rare “strokes” that can have pharmacological pre-treatment. The natural history of rebleeding and vasospasm are described as well as their effects on blood flow, oxygen delivery and metabolism. Strategies to ameliorate acute and delayed ischemia and hypoxia are discussed. Finally, potential pharmacotherapies are detailed.
Ruptured and Unruptured Intracranial Aneurysms – Surgical Outcome
Authors: Dix Gary A. , Gordon William , Kaufmann Anthony M. , Sutherland Ian S. , Sutherland Garnette R.
Published: February 2016

Background

The treatment of unruptured, intracranial aneurysms has been the topic of debate. Although recent studies have advocated surgical intervention for unruptured aneurysms, the risk of such treatment in comparison to outcome from ruptured aneurysms has not been established.

Method

This retrospective study examines the outcome of 134 patients with 179 ruptured and unruptured intracranial, saccular aneurysms treated by a single surgeon.

Results

Of the 98 ruptured aneurysms where early surgical intervention was undertaken (less than 48 hours post hemorrhage), 70 had an excellent outcome, 13 were good, four were moderate, two poor and nine patients died postoperatively. Outcome assessment in these cases was correlated to preoperative neurological status. Patients who presented with unruptured aneurysms fell into two categories: symptomatic and asymptomatic. Seven incidental, asymptomatic aneurysms were clipped concurrently to the surgical isolation of the culprit lesion following subarachnoid hemorrhage without influencing outcome, whilst, for varying reasons, eight unruptured aneurysms were not operated upon. Of the remaining 66 surgically treated, unruptured aneurysms, 64 had an excellent postoperative result, one was good (persisting right incomplete third nerve palsy) and one was moderate (left hemiparesis). Thirteen of these aneurysms were symptomatic, whilst 21 were asymptomatic, multiple aneurysms requiring secondary elective repair and 32 were true incidental aneurysms.

Conclusion

Unruptured aneurysms less than 25 mm in size may be safely, surgically treated relative to the expected natural history and, certainly, with less risk than operative intervention upon ruptured cerebral aneurysms.
Paradoxical Autonomic Response to Procyclidine in the Neuroleptic Malignant Syndrome
Authors: Balzan Martin V.
Published: February 2016

Background

Neuroleptic Malignant Syndrome (NMS) is an adverse reaction to dopamine receptor antagonists, characterised by hyperpyrexia, extrapyramidal rigidity and impaired autonomic function. It might result from central dopamine receptor blockade that causes severe muscle contraction.

Method

Case Study.

Results

High dose intravenous therapy with the anticholinergic drug, procyclidine hydrochloride, temporarily diminished the muscle rigidity and reversed most of the autonomic features in a patient with NMS occurring after a single intramuscular dose of the dopamine antagonist metoclopramide. Paradoxically, however, the heart rate decreased and bowel movements increased with this atropine-like drug.

Conclusion

Since the degree of tachypnoea, tachycardia, and bowel hypotonia closely paralleled the severity of the muscle rigidity, it is suggested that these autonomic features of NMS result from sustained muscle contraction rather than a direct effect of neuroleptic drugs on the central nervous system.
Huntington’s Disease: Recent Advances in Diagnosis and Management
Authors: Furtado Sarah , Suchowersky Oksana
Published: February 2016

Huntington’s Disease (HD) is a progressive degenerative disorder of the central nervous system inherited as an autosomal dominant trait. Clinically, the disorder is characterized by choreoathetosis (with age of onset typically in the late thirties or early forties) and neuropsychiatric disturbance. The striatum is particularly vulnerable to the degenerative disease process, with selective loss of medium spiny neurons and decreased levels of associated neurotransmitters, including substance P, GABA, met-enkephalin and dynorphin. Although the underlying pathophysiology is unknown, recent theories concerning pathogenesis have involved mitochondrial abnormalities and excitotoxin-mediated damage. The gene for HD has recently been discovered and characterized as an unstable CAG trinucleotide repeat sequence on the short arm of chromosome 4 (now known as IT 15). The direct test now available for the HD gene has facilitated disease diagnosis, particularly for those with unclear family history or chorea of uncertain origin; presymptomatic testing is also available. Management of affected individuals is unsatisfactory as only symptomatic control is available. However, as the effect of the genetic abnormality may soon be known, specific treatment of the disorder may become available in the near future.
Brachytherapy for Recurrent Single Brain Metastasis
Authors: Bernstein Mark , Cabantog Alberto , Laperriere Normand , Leung Phil , Thomason Cindy
Published: February 2016

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.