Neuropathology and applied neurobiology
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Neuropathol. Appl. Neurobiol. · Oct 2011
A comparative histological analysis of two models of nerve root avulsion injury in the adult rat.
This study has investigated the reliability of the artificial surgical model dorsal root rhizotomy (DRR), to the surgical tearing of the roots, avulsion, that occurs clinically. Root avulsion of the limb nerves is common in high-impact motor vehicle accidents and results in paraesthesia, paralysis and intractable pain. Limited treatment options are largely due to a lack of basic research on underlying mechanisms, and few animal models. We assess this limitation by histologically assessing the spatial and temporal injury profile of dorsal root avulsion (DRA) and DRR within the spinal cord. ⋯ Rhizotomy leads to a milder representation of the spinal cord trauma that occurs after 'true' avulsion injury. We recommend DRA be used in the future to more reliably model clinical avulsion injury. Avulsion is an injury with a chronic profile of degenerative and inflammatory progression, and this theoretically provides a window of clinical therapeutic opportunity in treatment of secondary trauma progression.
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Neuropathol. Appl. Neurobiol. · Oct 2011
ReviewReview: Contact sport-related chronic traumatic encephalopathy in the elderly: clinical expression and structural substrates.
Professional boxers and other contact sport athletes are exposed to repetitive brain trauma that may affect motor functions, cognitive performance, emotional regulation and social awareness. The term of chronic traumatic encephalopathy (CTE) was recently introduced to regroup a wide spectrum of symptoms such as cerebellar, pyramidal and extrapyramidal syndromes, impairments in orientation, memory, language, attention, information processing and frontal executive functions, as well as personality changes and behavioural and psychiatric symptoms. Magnetic resonance imaging usually reveals hippocampal and vermis atrophy, a cavum septum pellucidum, signs of diffuse axonal injury, pituitary gland atrophy, dilated perivascular spaces and periventricular white matter disease. ⋯ Molecular studies suggested that TBIs increase the neurotoxicity of the TAR DNA-binding protein 43 (TDP-43) that is a key pathological marker of ubiquitin-positive forms of frontotemporal dementia (FTLD-TDP) associated or not with motor neurone disease/amyotrophic lateral sclerosis (ALS). Similar patterns of immunoreactivity for TDP-43 in CTE, FTLD-TDP and ALS as well as epidemiological correlations support the presence of common pathogenetic mechanisms. The present review provides a critical update of the evolution of the concept of CTE with reference to its neuropathological definition together with an in-depth discussion of the differential diagnosis between this entity, AD and frontotemporal dementia.