Speech therapy and hyperbaric oxygen for aphasia after carbon monoxide intoxication.

Acute carbon monoxide (CO) intoxication may result in delayed neurological sequelae, which can include amnesia, ataxia, aphasia, emotional lability, disorientation, dysphagia, and other manifestations. A 27-year-old man reported symptoms of aphasia with agraphia and alexia in a review after CO intoxication. The patient received outpatient speech therapy, as well as repeated sessions of hyperbaric oxygen for 15 days, interspersing speech therapy with hyperbaric oxygen therapy for two months. After this period of combined treatment the aphasic symptomatology remitted, and oral and written language was normal. The complete disappearance of aphasia with agraphia and alexia confirms the efficacy of the combined intervention. More data from large clinical studies are needed to assess the outcomes of hyperbaric oxygen treatment in patients with delayed neurological sequelae after CO intoxication, but this case suggests it may be a good therapeutic option in combination with specific speech therapy.

Molecular neuroimaging in primary progressive aphasia with predominant agraphia.

A 62-year-old male presented with progressive isolated writing and spelling difficulties. Neurological, neuropsychological, speech, and language evaluations identified only minimal additional abnormalities. The presenting characteristics did not meet criteria for any particular variant of primary progressive aphasia; his clinical presentation is best described as primary progressive aphasia, with a predominant, almost pure agraphia. Brain MRI showed asymmetric, bilateral parenchymal volume loss, with left hippocampal atrophy. Fluorodeoxyglucose-F18 positron emission tomography showed hypometabolism in the lateral left frontal lobe, including Exner's area. Beta-amyloid and tau-positron emission tomography scans were negative, indicating the etiology was not Alzheimer's disease. The underlying neurodegenerative process is most likely related to TDP-43, although a 4-repeat tauopathy cannot be excluded. Following his clinical evolution, and ultimately identifying the underlying pathology from autopsy, will elucidate the etiology of this interesting clinical presentation.

The nature and treatment of phonological text agraphia.

Phonological alexia and agraphia are written language disorders characterised by disproportionate difficulty reading and spelling nonwords in comparison to real words. In phonological alexia, it has been shown that, despite relatively accurate reading of words in isolation, text-level reading deficits are often marked and persistent. Specifically, some individuals demonstrate difficulty reading functors and affixes in sentences, a profile referred to as phonological text alexia. In this paper, we demonstrate an analogous manifestation of the phonological impairment on text-level writing and suggest the term "phonological text agraphia". We examined four individuals with phonological alexia/agraphia who also showed disproportionate difficulty writing well-formed sentences in comparison to their grammatical competence in spoken utterances. Implementation of a phonological treatment protocol resulted in significantly improved sublexical phonology skills as well as improvements in grammatical accuracy of written narratives. These findings support the notion of a common phonological impairment underlying nonword reading/spelling deficits and sentence-level difficulties.

Lexical decision performance in developmental surface dysgraphia: Evidence for a unitary orthographic system that is used in both reading and spelling.

The relationship between spelling, written word recognition, and picture naming is investigated in a study of seven bilingual adults who have developmental surface dysgraphia in both Greek (their first language) and English (their second language). Four of the cases also performed poorly at orthographic lexical decision in both languages. This finding is consistent with similar results in Italian that have been taken as evidence of a developmental impairment to a single orthographic system that is used for both reading and spelling. The remaining three participants performed well at orthographic lexical decision. At first sight, preserved lexical decision in surface dysgraphia is less easy to explain in terms of a shared orthographic system. However, the results of subsequent experiments showed clear parallels between the nature of the reading and spelling difficulties that these three individuals experienced, consistent with the existence of a single orthographic system. The different patterns that were observed were consistent with the claims of Friedmann and Lukov (2008. Developmental surface dyslexias. Cortex, 44, 1146-1160) that several distinct sub-types of developmental surface dyslexia exist. We show that individual differences in spelling in surface dysgraphia are also consistent with these sub-types; there are different developmental deficits that can give rise, in an individual, to a combination of surface dyslexia and dysgraphia. Finally, we compare the theoretical framework used by Friedmann and her colleagues that is based upon the architecture of the DRC model with an account that relies instead upon the Triangle model of reading].

Lexical processing and distributional knowledge in sound-spelling mapping in a consistent orthography: A longitudinal study of reading and spelling in dyslexic and typically developing children.

This study examined the ability to master lexical processing and use knowledge of the relative frequency of sound-spelling mappings in both reading and spelling. Twenty-four dyslexic and dysgraphic children and 86 typically developing readers were followed longitudinally in 3rd and 5th grades. Effects of word regularity, word frequency, and probability of sound-spelling mappings were examined in two experimental tasks: (a) spelling to dictation; and (b) orthographic judgment. Dyslexic children showed larger regularity and frequency effects than controls in both tasks. Sensitivity to distributional information of sound-spelling mappings was already detected by third grade, indicating early acquisition even in children with dyslexia. Although with notable differences, knowledge of the relative frequencies of sound-spelling mapping influenced both reading and spelling. Results are discussed in terms of their theoretical and empirical implications.

Recognition of oral spelling is diagnostic of the central reading processes.

The task of recognition of oral spelling (stimulus: "C-A-T", response: "cat") is often administered to individuals with acquired written language disorders, yet there is no consensus about the underlying cognitive processes. We adjudicate between two existing hypotheses: Recognition of oral spelling uses central reading processes, or recognition of oral spelling uses central spelling processes in reverse. We tested the recognition of oral spelling and spelling to dictation abilities of a single individual with acquired dyslexia and dysgraphia. She was impaired relative to matched controls in spelling to dictation but unimpaired in recognition of oral spelling. Recognition of oral spelling for exception words (e.g., colonel) and pronounceable nonwords (e.g., larth) was intact. Our results were predicted by the hypothesis that recognition of oral spelling involves the central reading processes. We conclude that recognition of oral spelling is a useful tool for probing the integrity of the central reading processes.

Beyond the visual word form area: the orthography-semantics interface in spelling and reading.

Lexical orthographic information provides the basis for recovering the meanings of words in reading and for generating correct word spellings in writing. Research has provided evidence that an area of the left ventral temporal cortex, a subregion of what is often referred to as the visual word form area (VWFA), plays a significant role specifically in lexical orthographic processing. The current investigation goes beyond this previous work by examining the neurotopography of the interface of lexical orthography with semantics. We apply a novel lesion mapping approach with three individuals with acquired dysgraphia and dyslexia who suffered lesions to left ventral temporal cortex. To map cognitive processes to their neural substrates, this lesion mapping approach applies similar logical constraints to those used in cognitive neuropsychological research. Using this approach, this investigation: (a) identifies a region anterior to the VWFA that is important in the interface of orthographic information with semantics for reading and spelling; (b) determines that, within this orthography-semantics interface region (OSIR), access to orthography from semantics (spelling) is topographically distinct from access to semantics from orthography (reading); (c) provides evidence that, within this region, there is modality-specific access to and from lexical semantics for both spoken and written modalities, in both word production and comprehension. Overall, this study contributes to our understanding of the neural architecture at the lexical orthography-semantic-phonological interface within left ventral temporal cortex.

Written language production disorders: historical and recent perspectives.

Written language production is often the least examined neuropsychological function, yet it provides a sensitive and subtle sign to a variety of different behavioral disorders. The dissociation between written and spoken language and reading and writing first came to clinical prominence in the nineteenth century, with respect to ideas about localization of function. Twentieth century aphasiology research focused primarily on patients with unifocal lesions from cerebrovascular accidents, which have provided insight into the various levels of processing involved in the cognitively complex task of producing written language. Recent investigations have provided a broader perspective on writing impairments in a variety of disorders, including progressive and diffuse brain disorders, and functional brain imaging techniques have been used to study the underlying processes in healthy individuals.

Sluggish cognitive tempo: Association with neuropsychological test scores, motor incoordination, and dysgraphia in elementary school children.

Research on the relationship between sluggish cognitive tempo (SCT) and scores on neuropsychological tests (such as those measuring processing speed and reaction time) is inconclusive, and the association between SCT and motor incoordination and dysgraphia has not been objectively investigated. Mothers of 413 elementary school children (6-12 years of age) rated their children on the Pediatric Behavior Scale (PBS), which yields psychological problem scores, including SCT. Children were administered an extensive battery of neuropsychological tests assessing processing and performance speed, working memory, immediate and delayed recall, sustained attention, response inhibition, cognitive flexibility, fine motor manipulative skill, verbal fluency and retrieval, set shifting, and interference control, as well as intelligence and reading and math achievement. Only three of the 19 correlations between SCT and neuropsychological scores were significant, and all involved graphomotor tests (two timed and one untimed). In regression analysis, the strongest independent predictor of SCT was the maternal PBS incoordination factor score, followed by ratings of autism, inattention, and depression. Neuropsychological test scores did not contribute significantly more to predicting SCT. Among the incoordination PBS factor items, clumsy and draws or writes poorly were significant SCT predictors. Our novel and unexpected findings showed that motor incoordination was a stronger correlate of SCT than other variables assessed in our study, including those previously linked with SCT. Future SCT research needs to include measures of incoordination and dysgraphia in order to replicate and expand upon the current findings. Our results suggest that SCT traits are not reliably measured by currently available neuropsychological tests.

Hanja (Ideogram) alexia and agraphia in patients with semantic dementia.

Posterior fusiform gyrus (BA 37) is responsible for Hanja (ideogram) alexia in stroke patients. Patients with semantic dementia (SD) have lesions in the basal temporal area. The close proximity in these two lesions and the fact that reading ideograms requires holistic processing as is necessary in recognition of objects, suggests a possibility that ideogram alexia/agraphia may occur in patients with SD. We established and carried out Hanja and Hangul (phonogram) reading/writing tasks on six SD patients and nine Alzheimer's disease (AD) patients as control to see if these two patient groups show dissociation in the two sets of tests. SPM analysis was performed on the SD patients' PET images to look for any dysfunctions in the posterior fusiform gyrus. The SD patients manifested Hanja alexia/agraphia whereas Hangul reading/writing ability was relatively preserved. There were group differences between SD and AD in the Hanja tasks but not in the Hangul tasks. The SPM analysis revealed no hypometabolism in the posterior fusiform gyrus, but only in the middle and the anterior part of the temporal gyrus. Dysfunction in the middle temporal gyrus (BA 21) may have disrupted the temporal lobe connections preventing the function of the posterior fusiform gyrus.

Distinctions between orthographic long-term memory and working memory.

Research in the cognitive and neural sciences has long posited a distinction between the long-term memory (LTM) storage of information and the short-term buffering of information that is being actively manipulated in working memory (WM). This basic type of distinction has been posited in a variety of domains, including written language production-spelling. In the domain of spelling, the primary source of empirical evidence regarding this distinction has been cognitive neuropsychological studies reporting deficits selectively affecting what the cognitive neuropsychological literature has referred to as the orthographic lexicon (LTM) or the graphemic buffer (WM). Recent papers have reexamined several of the hallmark characteristics of impairment affecting the graphemic buffer, with implications for our understanding of the nature of the orthographic LTM and WM systems. In this paper, we present a detailed case series study of 4 individuals with acquired spelling deficits and report evidence from both error types and factors influencing error rates that support the traditional distinction between these cognitive systems involved in spelling. In addition, we report evidence indicating possible interaction between these systems, which is consistent with a variety of recent findings in research on spelling.

Neologistic jargon aphasia and agraphia in primary progressive aphasia.

The terms 'jargon aphasia' and 'jargon agraphia' describe the production of incomprehensible language containing frequent phonological, semantic or neologistic errors in speech and writing, respectively. Here we describe two patients with primary progressive aphasia (PPA) who produced neologistic jargon either in speech or writing. We suggest that involvement of the posterior superior temporal-inferior parietal region may lead to a disconnection between stored lexical representations and language output pathways leading to aberrant activation of phonemes in neologistic jargon. Parietal lobe involvement is relatively unusual in PPA, perhaps accounting for the comparative rarity of jargon early in the course of these diseases.

Emergence and progression of 'non-semantic' deficits in semantic dementia.

Although semantic dementia (SD) is defined as a selective disruption of conceptual knowledge, a number of group studies have now demonstrated that SD patients also show impaired performance on tasks not usually considered to have a high semantic load (e.g., reading words aloud and lexical or object decision). The aim of the current study was to document the relative deterioration, over time, of a number of semantic and so-called 'non-semantic' tasks in LF, a single case of SD for whom - by virtue of his work as a published cartoonist - we also have extensive data regarding his pre-morbid linguistic and drawing skills. In five testing rounds over a period of five years we administered semantic tests of object naming and object definition (on both of which LF was progressively impaired, as expected for a diagnosis of SD), plus verbal and non-verbal 'non-semantic' tasks of reading aloud, spelling, object and lexical decision, and delayed copy drawing. Initially, his only striking 'non-semantic' deficit was in the domain of spelling - a pronounced surface dysgraphia in an individual with demonstrably superior pre-morbid spelling skill. Over time, and in line with his declining semantic system, LF's performance gradually deteriorated on all of the 'non-semantic' tasks. The most vulnerable items on most tasks were those with low frequency and an atypical form. This report adds to the growing body of evidence that a number of cognitive processes not usually considered to be 'semantic' in their demands rely on the integrity of semantic knowledge for successful execution. Furthermore, it provides the first indication that these non-semantic deficits might emerge in an order predictable from the typicality structure of the relevant domain.

Integration of lexical and sublexical processing in the spelling of regular words: a multiple single-case study in Italian dysgraphic patients.

In this study we investigated 12 cases of "mixed dysgraphia", a spelling impairment where regular words are spelt better than either ambiguous words or regular non-words. Two explanations of mixed dysgraphia were formerly offered by Luzzatti et al. (1998): (i) a double functional lesion of the orthographic output lexicon (or damage to its access) and of the acoustic-to-phonological conversion; and (ii) some kind of interaction/summation between lexical and sublexical spelling routes when processing regular words. We first analysed whether a double functional lesion was sufficient to explain the mixed dysgraphia, checking acoustic-to-phonological conversion by means of the repetition of words and non-words: the answer was positive in five cases and uncertain in three. We tested the remaining four cases to see if there was an interaction between lexical and sublexical processing of regular words, quantifying for each patient, on a probabilistic basis, the separate contribution of the residual lexical and sublexical resources. We investigated whether the processing along these routes was simultaneous but independent ("independent cooperation") or if instead there was "interaction", i.e., the simultaneous activity led to an added increase of efficiency over and above the mere combination of separate success probabilities. For one case the processing along the two routes was independent, in the other three cases an interaction resulted. Following the same approach, we found that for the five cases with a double functional lesion, the observed success on regular word spelling was higher than that expected on a probabilistic basis, but the interpretation of this finding was different.

Does surface dyslexia/dysgraphia relate to semantic deficits in the semantic variant of primary progressive aphasia?

The semantic variant of primary progressive aphasia (sv-PPA) is a degenerative condition which causes surface dyslexia/dysgraphia, resulting in reading/writing errors of irregular words with non-transparent grapheme-to-phoneme correspondences (e.g., 'plaid') as opposed to regular words (e.g., 'cat'). According to connectionist models, most authors have attributed this deficit to semantic impairments, but this assumption is at odds with symbolic models, such as the DRC account, stating that the reading/writing of irregulars relies on the mental lexicon. Our study investigated whether sv-PPA affects the lexicon in addition to the semantic system, and whether semantic or lexical deficits cause surface dyslexia/dysgraphia, while challenging the two major models of written language. We explored a cohort of 12 sv-PPA patients and 25 matched healthy controls using a reading and writing task, a semantic task (category decision: living vs. non-living), and a lexical task (lexical decision: word vs. no-neighbor non-word). Correlation analyses were conducted to assess the relationship between reading/writing scores of irregulars and semantic vs. lexical performance. Furthermore, item-by-item analyses explored the consistency of reading/writing errors with item-specific semantic and lexical errors. Results showed that sv-PPA patients are impaired at reading and writing irregular words, and that they have impaired performance in both the semantic and the lexical task. Reading/writing scores with irregulars correlated significantly with performance in the lexical but not the semantic task. Item-by-item analyses revealed that failure in the lexical task on a given irregular word is a good predictor of reading/writing errors with that item (positive predictive value: 77.5%), which was not the case for the semantic task (positive predictive value: 42.5%). Our findings show that sv-PPA is not restricted to semantic damage but that it also comprises damage to the mental lexicon, which appears to be the major factor for surface dyslexia/dysgraphia. Our data support symbolic models whereas they challenge connectionist accounts.

Allographic agraphia: a case study.

We report the case of patient MN, diagnosed with frontotemporal dementia, who exhibited a severe impairment in writing letters and words in upper-case print in the face of accurate production of the same stimuli in lower-case cursive. In contrast to her written production difficulties, MN was unimpaired in recognizing visually presented letters and words in upper-case print. We find a modest benefit of visual form cueing in the written production of upper-case letters, despite an inability to describe or report visual features of letters in any case or font. This case increases our understanding of the allographic level of letter-shape representation in written language production. It provides strong support for previous reports indicating the neural independence of different types of case and font-specific letter-shape information; it provides evidence that letter-shape production does not require explicit access to information about the visual attributes of letter shapes and, finally, it reveals the possibility of interaction between processes involved in letter-shape production and perception.

Dysgraphia in patients with primary lateral sclerosis: a speech-based rehearsal deficit?

The present study aims to demonstrate that errors when writing are more common than expected in patients affected by primary lateral sclerosis (PLS) with severe dysarthria or complete mutism, independent of spasticity. Sixteen patients meeting Pringle's et al. [34] criteria for PLS underwent standard neuropsychological tasks and evaluation of writing. We assessed writing abilities in spelling through dictation in which a set of words, non-words and short phrases were presented orally and by composing words using a set of preformed letters. Finally, a written copying task was performed with the same words. Relative to controls, PLS patients made a greater number of spelling errors in all writing conditions, but not in copy task. The error types included: omissions, transpositions, insertions and letter substitutions. These were equally distributed on the writing task and the composition of words with a set of preformed letters. This pattern of performance is consistent with a spelling impairment. The results are consistent with the concept that written production is critically dependent on the subvocal articulatory mechanism of rehearsal, perhaps at the level of retaining the sequence of graphemes in a graphemic buffer. In PLS patients a disturbance in rehearsal opportunity may affect the correct sequencing/assembly of an orthographic representation in the written process.

Writing errors and anosognosia in amyotrophic lateral sclerosis with dementia.

Amyotrophic lateral sclerosis (ALS) with dementia (ALS-D) is known to exhibit characteristics of frontotemporal dementia. However, in clinical situations, it is often difficult to evaluate their cognitive functions because of impaired voluntary speech and physical disabilities. In order to identify characteristic and diagnostic cognitive symptoms of relatively advanced ALS-D patients, we retrospectively reviewed the clinical features of seven cases of clinically definitive ALS who had dementia, impaired voluntary speech, and physical disability. Their medical records showed that six out of seven patients made writing errors, and all of the patients demonstrated anosognosia. The writing errors consisted of paragraphia such as substitution, omission, or syntactic errors with individual differences in error types. Dissociation between kana and kanji were also observed. Anosognosia was evaluated by a self-rating scale with which the patients and the medical staff evaluated the patient's physical ability; the results indicated a large discrepancy between the evaluation by the patients and the medical staff. We emphasize that aphasic writing errors have been underestimated, particularly in ALS-D patients with impaired voluntary speech. We also reported that anosognosia was the most important and quantifiable symptom in ALS-D. The relationship between writing errors and anosognosia should be investigated further.

Developmental dysgraphia is often associated with minor neurological dysfunction in children with developmental coordination disorder (DCD).

OBJECTIVES: Children with developmental coordination disorder (DCD) are particularly affected by handwriting disorders, which remain poorly understood and are not clearly defined. The aim of our study is to provide a better understanding of handwriting disorders, and specifically of dysgraphia in children with DCD. METHODS: Sixty-five children with DCD (5-15 years), enrolled according to DSM-5, were assessed with handwriting testing and standardized assessments of neuropsychological, neurovisual, MRI and neuropsychomotor functions, with special attention paid to muscular tone examination. RESULTS: While handwriting disorders were strongly represented in our sample of children with DCD (89%), dysgraphia appeared uncommon (17%) and was closely related to several specific dysfunctions of laterality establishment; mild pyramidal tract dysfunction with distal phasic stretch reflex (PSR) in lower limbs; digital praxis slowness (both P<0.05). DISCUSSION: In our sample, dysgraphia was closely related to minor neurological dysfunction (MND) suggesting a disturbance of motor control at the level of the corticospinal motor pathway. This highlights the uncommon character of dysgraphia in children with DCD for which diagnosis should be made through a particular attention to evaluation of MND with muscular tone examination. This consideration, both in the research setting and in clinical practice, appears necessary to avoid inaccurate clinical diagnosis and to optimize appropriate therapeutic management.

Do deep dyslexia, dysphasia and dysgraphia share a common phonological impairment?

This study directly compared four patients who, to varying degrees, showed the characteristics of deep dyslexia, dysphasia and/or dysgraphia--i.e., they made semantic errors in oral reading, repetition and/or spelling to dictation. The "primary systems" hypothesis proposes that these different conditions result from severe impairment to a common phonological system, rather than damage to task-specific mechanisms (i.e. grapheme-phoneme conversion). By this view, deep dyslexic/dysphasic patients should show overlapping deficits but previous studies have not directly compared them. All four patients in the current study showed poor phonological production across different tasks, including repetition, reading aloud and spoken picture naming, in line with the primary systems hypothesis. They also showed severe deficits in tasks that required the manipulation of phonology, such as phoneme addition and deletion. Some of the characteristics of the deep syndromes - namely lexicality and imageability effects - were typically observed in all of the tasks, regardless of whether semantic errors occurred or not, suggesting that the patients' phonological deficits impacted on repetition, reading aloud and spelling to dictation in similar ways. Differences between the syndromes were accounted for by variation in other primary systems--particularly auditory processing. Deep dysphasic symptoms occurred when the impact of phonological input on spoken output was disrupted or reduced, either as a result of auditory/phonological impairment, or for patients with good phonological input analysis, when repetition was delayed. 'Deep' disorders of reading aloud, repetition and spelling can therefore be explained in terms of damage to interacting primary systems such as phonology, semantics and vision, with phonology playing a critical role.