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• Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques close

AbstractThis paper describes the development and testing of a computer algorithm to automate the process of peak identification and somatosensory evoked potential (SSEP) grading. We tested the accuracy of computerized peak detection and evaluated grading schemes using a test set of 60 SSEPs ranked from worst to best by the programmer (RJM) and a blinded grader (PO). The computer algorithm recognized 95% of peaks identified by visual inspection. Twelve percent of peaks identified by the computer were noise. Summed peak to peak amplitude gave the most accurate ranking of SSEPs. Rank correlation between computer and blinded and unblinded expert grading was r = .82 for PO, r = .92 for RJM, p < .0001 for both. Computer and manually summed amplitudes were highly correlated (Pearson r = .98, p < .0001). Correlation between the 2 expert graders was .86, p < .0001. Computer graded SSEPs were significantly related to clinical outcome at 3 months, p < .0001. Automatic grading of SSEPs using summed peak to peak amplitude is highly correlated with expert grading. The measure is objective, continuous, and well suited to statistical analysis.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by abnormalities of movement and dementia. No curative treatment is available and HD results in gradually increasing disability. Characterization of the genetic abnormality has dramatically increased our understanding of the underlying mechanisms of the disease process, and has resulted in the development of a number of genetic models. These research tools are forming the basis of advanced work into the diagnosis, pathophysiology, and potential treatment of the disease. Clinically, the availability of genetic testing has eased confirmation of diagnosis in symptomatic individuals. Presymptomatic testing allows at-risk individuals to make informed choices but requires supportive care from physicians. Current clinical treatment is focused on symptom control. Advances in research have resulted in the development of potential neuroprotective strategies which are undergoing clinical testing.

Abstract:Objective:In order to characterize the nature and extent of neuropsychological dysfunction in primary lateral sclerosis (PLS), we studied prospectively cognitive, emotional, and behavioral functioning in PLS, and compared performances to functioning in amyotrophic lateral sclerosis (ALS).Methods:Eighteen patients with PLS and 13 patients with ALS completed a neuropsychological test battery assessing both cognitive skills and emotional/behavioral functioning.Results:Both PLS and ALS groups scored broadly within normal limits (mean T-scores greater than 40) on all cognitive measures and no significant between-group differences were found with the exception of one variable. However, when examined on a case by case basis, the data revealed considerable heterogeneity amongst patients in both groups. Overall, 39% of PLS patients and 31% of ALS patients were considered cognitively impaired. A higher than expected frequency of abnormal scores was noted for several tests of executive function in both groups, and a majority of PLS patients also exhibited abnormal behavioural symptoms. There was no relationship in PLS or ALS groups between cognitive functioning and disease duration, current site of disease, site of onset, functional status, and respiratory variables. Comparison between the PLS and ALS groups indicated virtually no differences in cognitive test scores and overall emotional/behavioural symptoms.Conclusions:We observed deficits in cognition and behaviour in a significant proportion of PLS patients which were comparable to those observed in ALS cases. Although deficits were not in the range of frontotemporal dementia, both ALS and PLS cases demonstrated deficits most prominently on tests of executive functioning.

ABSTRACT:Malignant astrocytomas are aggressive neoplasms with a dismal prognosis despite optimal treatment. Maximal resective surgery is traditionally complemented by radiation therapy. Chemotherapy is now used on patients as initial therapy when their functional status is congruent with further treatment. The classic agents used are nitrosoureas, but temozolomide has taken the front seat recently, with recent data demonstrating increased survival when this agent is used concurrently with radiation therapy in newly diagnosed glioblastoma patients. A new class of agents, refered to as biological modifiers, are increasingly used in clinical trials in an effort to affect the intrinsic biologic aberrations harboured by tumor cells. These drugs comprise differentiation agents, anti-angiogenic agents, matrix-metalloproteinase inhibitors and signal transduction inhibitors, among others. This article reviews the standard cytotoxic agents that have been used to treat malignant astrocytomas, and the different combination regimens offering promise. In addition, recent advances with biological modifiers are also discussed.

ABSTRACT:Hemophagocytic lymphohistiocytosis (HLH) is a rare immune deregulatory disorder that predominantly presents in children. Here we describe three patients with adult-onset primary HLH whose initial presentations were characterized by neurological features, and we review the literature of published cases. These cases ranged in age from 17 to 30 and presented with a variety of neurological symptoms. One of our cases demonstrated numerous microhemorrhages on MR brain. This is the first published case of adult-onset HLH presenting with cerebral microhemorrhages. In addition, literature review identified five additional patients with isolated central nervous system presentation of primary HLH.

ABSTRACT:Interventional neuroradiology (INR) has evolved from a hybrid mixture of daring radiologists and iconoclastic neurosurgeons into a multidisciplinary specialty, which has become indispensable for cerebrovascular and neurological centers worldwide. This manuscript traces the origins of INR and describes its evolution to the present day. The focus will be on cerebrovascular disorders including aneurysms, stroke, brain arteriovenous malformations, dural arteriovenous fistulae, and atherosclerotic disease, both intra- and extracranial. Also discussed are cerebral vasospasm, venolymphatic malformations of the head and neck, tumor embolization, idiopathic intracranial hypertension, inferior petrosal venous sinus sampling for Cushing’s disease, and spinal interventions. Pediatric INR has not been included and deserves a separate, dedicated review.

ABSTRACT:MS could well be a two stage disease. The first stage involves the sequential development of multiple small lesions, mostly inflammatory, that accumulate at a given rate. The second stage could be that of consolidation and confluence of lesions that involves not only demyelination but gliosis. MRI now gives us an opportunity to watch the evolution of these processes and also to monitor treatment effects. It is only after the evolution of this process is understood that we can design rational therapies directed toward the prevention of spasticity in MS.

ABSTRACT:Parental age at the time of birth of 133 clinically diagnosed Alzheimer patients from the Saguenay-Lac-St-Jean area (Quebec, Canada) were compared with those of 6 control groups formed out a population registry. The birth order of the Alzheimer patients was also analyzed. The results did not show any parental age or birth order effect, which is in agreement with previous reports. The importance of control selection in such studies is stressed.

ABSTRACT:Intracranial venous sinus thrombosis is an uncommon cause of pseudotumor cerebri. The diagnosis is often not confirmed on the rationale that treatment will not be altered. We report a case presenting a pseudotumor cerebri where the underlying pathology disclosed dural sinus thrombosis resulting from compression by an eosionophilic granuloma of the occipital bone. Routine CT of the head and Technetium-99m brain scan initially demonstrated neither tumor nor thrombosis. Plain skull x-rays subsequently revealed a lytic lesion of the occiput. When reinvestigated with CT using bone density windows the tumor was revealed. Excision of the tumor and a short course of cobalt therapy was curative. Special techniques in nuclear scanning, CT and MRI designed to improve the sensitivity for diagnosing venous sinus thrombosis are described. This case illustrates the importance of establishing a definitive diagnosis and shows the importance of pre-test consultation between clinicians and radiologists to ensure that specific investigative techniques are properly utilized.