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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 78-year-old right handed man with a past history of atrial fibrillation developed in November 1994, a slight right hemiparesis with aphasia which cleared over one month. Head CT scan showed a left middle cerebral artery infarct involving the posterior part of the temporal lobe. In September 1995, a second stroke occurred. Head CT scan revealed a recent right middle cerebral artery infarct within the posterior part of temporal cortex. Auditory agnosia was diagnosed. Auditory evoked potentials recording showed bilateral dysfunction of central auditory pathways mainly over the right hemisphere. Clinical data and evoked potentials suggest that auditory agnosia might be related to the right temporal lobe damage. This later is involved in linguistic processes as suggested by positron emission tomography studies.
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PMID:[Auditory perception disorders due to bilateral cortical lesions. An electrophysiology study]. 977 59

MELAS is commonly associated with peripheral hearing loss. Auditory agnosia is a rare cortical auditory impairment, usually due to bilateral temporal damage. We document, for the first time, auditory agnosia as the presenting hearing disorder in MELAS. A young woman with MELAS (A3243G mtDNA mutation) suffered from acute cortical hearing damage following a single stroke-like episode, in the absence of previous hearing deficits. Audiometric testing showed marked central hearing impairment and very mild sensorineural hearing loss. MRI documented bilateral, acute lesions to superior temporal regions. Neuropsychological tests demonstrated auditory agnosia without aphasia. Our data and a review of published reports show that cortical auditory disorders are relatively frequent in MELAS, probably due to the strikingly high incidence of bilateral and symmetric damage following stroke-like episodes. Acute auditory agnosia can be the presenting hearing deficit in MELAS and, conversely, MELAS should be suspected in young adults with sudden hearing loss.
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PMID:Acute auditory agnosia as the presenting hearing disorder in MELAS. 1901 35

Auditory agnosia is an inability to make sense of sound that cannot be explained by deficits in low-level hearing. In view of recent promising results in the area of neurorehabilitation of language disorders after stroke, we examined the effect of transcranial direct current stimulation (tDCS) in a young woman with general auditory agnosia caused by traumatic injury to the left inferior colliculus. Specifically, we studied activations to sound embedded in a block design using functional magnetic resonance imaging before and after application of anodal tDCS to the right auditory cortex. Before tDCS, auditory discrimination deficits were associated with abnormally reduced activations of the auditory cortex and bilateral unresponsiveness of the anterior superior temporal sulci and gyri. This session replicated a previous functional scan with the same paradigm a year before the current experiment. We then applied anodal tDCS over right auditory cortex for 20 min-utes and immediately re-scanned the patient. We found increased activation of bilateral auditory cortices and, for speech sounds, selectively increased activation in Broca's and Wernicke's areas. Future research might consider the long-term behavioral effects after neurostimulation in auditory agnosia and its potential use in the neurorehabilitation of more general auditory disorders.
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PMID:Neuromodulation of Right Auditory Cortex Selectively Increases Activation in Speech-Related Brain Areas in Brainstem Auditory Agnosia. 3023 65

Aphasia typically is associated with comparable difficulties in written and spoken modalities of language expression and comprehension. In contrast, auditory verbal agnosia is the disproportionate difficulty comprehending spoken compared to written language, also typically greater than difficulties with spoken and written language expression, in the absence of a primary sensory deficit. The terms pure word deafness and auditory verbal agnosia are often used synonymously. However, the broader term of auditory agnosia more accurately reflects difficulty processing both speech and non-speech sounds whereas individuals with auditory verbal agnosia (pure word deafness) have preserved processing of environmental sounds. Auditory agnosia is reported in the stroke literature, but rarely reported in progressive neurologic disorders. Here, we report a case of a woman who presented with what is best described as a prominent auditory deficit in the context of an initially unclassifiable, or mixed, primary progressive aphasia (PPA) with accompanying apraxia of speech. Her clinical presentation shared features with auditory agnosia, although sensory functioning was not formally assessed. We report clinical and neuroimaging data spanning 6 years and subsequent autopsy results. She presented at 65 years of age, 5 years post onset of symptoms that included insidious and progressive difficulties thinking of words, constructing sentences, pronouncing words, and understanding instructions. She had disproportionate difficulty with comprehension of spoken compared to written language. She eventually developed features of the nonfluent/agrammatic variant of PPA, as well as an apraxia of speech. Imaging with [18F]-fluorodeoxyglucose (FDG)-PET revealed progression of bilateral (left greater than right) hypometabolism involving the frontal, temporal (predominantly the lateral superior gyrus), and parietal lobes, that eventually included the supplementary motor area, anterior cingulate, and caudate. Autopsy revealed pathological lesions consistent with corticobasal degeneration.
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PMID:Prominent auditory deficits in primary progressive aphasia: A case study. 3103 Aug 98