Monthly Archives: June 2010
Two cases of frontotemporal dementia with predominant temporal lobe atrophy
Frontotemporal dementia (FTD) is a subtype of frontotemporal lobar degeneration, which also includes semantic dementia (SD) and progressive non-fluent aphasia. Frontotemporal dementia is characterized by changes in personality and behavioral abnormalities, generally associated with predominant frontal lobe atrophy. Conversely, SD is typically characterized by Gogi (word meaning) aphasia based on semantic memory impairment and is associated with predominant temporal lobe atrophy. However, in the present cases, we diagnosed FTD on the basis of clinical symptoms, such as disinhibition, indifference, and stereotypy, without semantic memory impairment, even though neuroimaging showed predominant temporal lobe atrophy. We suggest that clinical symptoms are the most important cues for an accurate clinical diagnosis and there is no exclusive relationship between the syndrome and atrophy of the temporal lobes.
from Psychogeriatrics
Cochlear implantations in young children with cochlear nerve deficiency diagnosed by MRI
Young children with nonvisualized cochlear nerve on MRI showed worse outcomes compared to the children with normal cochlear nerve. Cochlear nerve deficiency on MRI is a marker of very poor outcome with cochlear implantations.
Cost analysis of intubation-related tracheal injury using a national database
Tracheal injury from ETI is associated with a significant increase in healthcare costs that accrue both during the index admission and during subsequent hospitalizations required to treat the injury.
Extracts from The Cochrane Library: Interventions for acute otitis externa
The “Cochrane Corner” is a quarterly section in the Journal that highlights systematic reviews relevant to otolaryngology–head and neck surgery, with invited commentary to aid clinical decision making. This installment features a Cochrane Review titled “Interventions for acute otitis externa,” which supports topical therapy as the treatment of choice, but is unable to draw conclusions about the comparative efficacy of available topical preparations.
The diagnostic value of diffusion-weighted magnetic resonance imaging in detecting a residual cholesteatoma
In this evidence-based case report, we address the following clinical question: What is the predictive value of diffusion-weighted magnetic resonance imaging (DW MRI) for detecting a residual cholesteatoma in patients with chronic otitis media with cholesteatoma who have previously undergone a canal-wall-up procedure? We searched for relevant synonyms for the determinant, MRI, and for the outcome, cholesteatoma, and retrieved relevant publications in Embase, PubMed, Cinahl, and Web of Science by using search terms in the title and abstract fields. The search yielded 683 records, of which 11 were relevant and valid for our clinical question. We pooled the data of the MRI findings of the included studies by adding the two-by-two tables of the individual studies. For the eight echo planar imaging (EPI) DW MRI studies, this resulted in a pooled sensitivity, specificity, positive predictive value, and negative predictive value of 68 percent, 87 percent, 81 percent, and 78 percent, respectively. For the three non-echo planar (non-EPI) DW MRI studies, the sensitivity, specificity, positive predictive value, and negative predictive value were 97 percent, 97 percent, 97 percent, and 97 percent, respectively. DW MRI, especially the non-EPI DW MRI, appears to be a rather accurate method, as opposed to a standard second-look operation, for the follow-up of patients who have undergone a canal-wall-up procedure for a chronic otitis media with cholesteatoma and who have no clinical signs of recurrent cholesteatoma.
Benign Paroxysmal Positional Vertigo
Benign paroxysmal positional vertigo is a common peripheral vestibular disorder. It is caused by loose otoconia, which detach from the utricular macula and fall into any one of the three semicircular canals. Patients report brief episodes of rotary vertigo triggered by changes in head position. The most common form of the disorder affects the posterior semicircular canal and is diagnosed with the Dix–Hallpike maneuver. A positive Dix–Hallpike test is manifested as upbeating torsional nystagmus with a fast component that rotates toward the undermost ear (video).
Stendhal’s aphasic spells: the first report of transient ischemic attacks followed by stroke.
In March 1841, the year before he died of acute stroke, Stendhal, one of the most famous French novelists of the 19th century, developed a series of short-lived speech impairments which he precisely reported in his correspondence. His reports suggest that these spells were aphasic transient ischemic attacks (TIAs). The accuracy and precision of Stendhal’s description exactly 20 years before Broca’s presentation at the Société d’Anthropologie is remarkable since it occurred at a time when TIAs had not been studied in the medical literature and aphasia was still in its ‘prehistory’. Stendhal’s TIAs a few months before his fatal stroke constitute the first historical report of the warning nature of TIAs, which would be emphasized only over 100 years later. Copyright (c) 2010 S. Karger AG, Basel.
‘The adventure’: Charles-Ferdinand Ramuz’s extraordinary stroke diary.
The famous Swiss writer Charles-Ferdinand Ramuz suffered a stroke at 65 years, which he called ‘the adventure’ or ‘the accident’. He developed language disturbances suggesting crossed aphasia in a right hander with left hemiparesis. This uncommon pattern allowed him to continue to write his diary and to report his disturbances, with a unique depth and precision, especially for cognitive-emotional changes. Language and motor dysfunction recovered within a few weeks, but Ramuz complained of persisting emotional flattening alternating with irritability, fatigue, depression, anxiety, and concentration difficulty, which gave him the feeling to have become another person and to be inhabited by a stranger, whom he compared with devils. Ramuz fought several months to resume his literary activity, having the impression to have lost inspiration and creativity. However, the novels he wrote less than 6 months after stroke show no stylistic changes and have been found to be of the same quality as his previous production. Ramuz even ‘used’ his stroke experience in his work, in particular in a novel depicting an old man who has a stroke and dies of it. Ramuz’s diary, with his own daily description of stroke features and consequences during acute and recovery phases, is a unique document in a writer of his importance, and provides invaluable information on subjective emotional and cognitive experience of stroke. Copyright (c) 2010 S. Karger AG, Basel.
How Does Learning to Read Affect Speech Perception?
Behavioral studies have demonstrated that learning to read and write affects the processing of spoken language. The present study investigates the neural mechanism underlying the emergence of such orthographic effects during speech processing. Transcranial magnetic stimulation (TMS) was used to tease apart two competing hypotheses that consider this orthographic influence to be either a consequence of a change in the nature of the phonological representations during literacy acquisition or a consequence of online coactivation of the orthographic and phonological representations during speech processing. Participants performed an auditory lexical decision task in which the orthographic consistency of spoken words was manipulated and repetitive TMS was used to interfere with either phonological or orthographic processing by stimulating left supramarginal gyrus (SMG) or left ventral occipitotemporal cortex (vOTC), respectively. The advantage for consistently spelled words was removed only when the stimulation was delivered to SMG and not to vOTC, providing strong evidence that this effect arises at a phonological, rather than an orthographic, level. We propose a possible mechanistic explanation for the role of SMG in phonological processing and how this is affected by learning to read.
from the Journal of Neuroscience
Autism Spectrum Disorder in Children and Adolescents with Fragile X Syndrome: Within-Syndrome Differences and Age-Related Changes.
The Autism Diagnostic Interview-Revised was used to examine diagnostic profiles and age-related changes in autism symptoms for a group of verbal children and adolescents with FXS, with and without autism. After controlling for nonverbal IQ, statistically significant between-group differences for lifetime and current autism symptoms were found for the Communication and Restricted Interests/Repetitive Behaviors domains, but not the Reciprocal Social Interaction domain. Effect sizes for differences in Reciprocal Social Interaction also were smaller than effect sizes for the other domains with one exception. Overall, severity of autism symptoms improved with age for all participants, with the least improvement noted for Restricted Interests and Repetitive Behaviors. FMRP did not account for unique variance in autism symptoms over and above nonverbal IQ.
from American Journal on Intellectual and Developmental Disabilities
Investigation of Tinnitus Patients in Italy: Clinical and Audiological Characteristics
Tinnitus is a distressing symptom, provoking an important decrease in the quality of life in 20% of tinnitus sufferers, that is strongly correlated to many factors. This paper, according to literature data, suggests that the hearing status and the old age represent the principal tinnitus-related factors; in most cases tinnitus is high-pitched and it is associated to high-frequency hearing loss with a significant statistical correlation between the two variables. The analysis of relationship between tinnitus severity (expressed as THI scores) and tinnitus loudness match clearly demonstrate lack of correlation between these variables. This finding support the possibility that neural connection involved in evoking tinnitus-related negative reactions is governed by conditioned reflexes.
Constrained principal component analysis reveals functionally connected load-dependent networks involved in multiple stages of working memory
Constrained principal component analysis (CPCA) with a finite impulse response (FIR) basis set was used to reveal functionally connected networks and their temporal progression over a multistage verbal working memory trial in which memory load was varied. Four components were extracted, and all showed statistically significant sensitivity to the memory load manipulation. Additionally, two of the four components sustained this peak activity, both for approximately 3 s (Components 1 and 4). The functional networks that showed sustained activity were characterized by increased activations in the dorsal anterior cingulate cortex, right dorsolateral prefrontal cortex, and left supramarginal gyrus, and decreased activations in the primary auditory cortex and default network regions. The functional networks that did not show sustained activity were instead dominated by increased activation in occipital cortex, dorsal anterior cingulate cortex, sensori-motor cortical regions, and superior parietal cortex. The response shapes suggest that although all four components appear to be invoked at encoding, the two sustained-peak components are likely to be additionally involved in the delay period. Our investigation provides a unique view of the contributions made by a network of brain regions over the course of a multiple-stage working memory trial. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc.
from Human Brain Mapping
Functional Topography of the Cerebellum in Verbal Working Memory
Speech—both overt and covert—facilitates working memory by creating and refreshing motor memory traces, allowing new information to be received and processed. Neuroimaging studies suggest a functional topography within the sub-regions of the cerebellum that subserve verbal working memory. Medial regions of the anterior cerebellum support overt speech, consistent with other forms of motor execution such as finger tapping, whereas lateral portions of the superior cerebellum support speech planning and preparation (e.g., covert speech). The inferior cerebellum is active when information is maintained across a delay, but activation appears to be independent of speech, lateralized by modality of stimulus presentation, and possibly related to phonological storage processes. Motor (dorsal) and cognitive (ventral) channels of cerebellar output nuclei can be distinguished in working memory. Clinical investigations suggest that hyper-activity of cerebellum and disrupted control of inner speech may contribute to certain psychiatric symptoms.
