Word Deafness Research Articles

Prelingual auditory verbal agnosia, A rare condition

Auditory agnosia, agnosia for speech is a rare condition, caused mostly by stroke, in adults, while in children it is often a sequel of herpes simplex encephalitis or is associated with epilepsy, in Landau–Kleffner syndrome. This article presents a rare case of verbal auditory agnosia as a result of meningoencephalitis, caused probably by herpes simplex virus. The patient's developed encephalitis at the age of 1 year and 4 months. After her recovery, the family noticed the absence of language development. She was initially diagnosed with profound hearing loss, and the hearing aids did not help her. The speech therapy developed her lip-reading skills with a hard-to-understand pronunciation. Later, audiometry showed a nearly normal peripheral auditory system and magnetic resonance imaging revealed the characteristic brain lesions in both the temporal lobes, explaining the patient's evolution. Assessment of children with delayed speech development must consider the central hearing disorders as a differential diagnosis.

Neuropsychological Assessment of Children with Landau-Kleffner Syndrome

Landau–Kleffner syndrome (LKS) is an epileptic encephalopathy that is marked by sudden onset of verbal auditory agnosia and subsequent deterioration in expressive language. The primary deficit is in phonological processing, possibly at the level of impaired phonological short-term memory, and it appears to create a cascade of cognitive deterioration that impacts all aspects of speech comprehension. Inability to recognize nonverbal auditory stimuli may also be present but may not emerge until later in the condition. Language recovery may occur in about one-third of patients and appears to be precipitated by resolution of the EEG abnormalities. Nonverbal intelligence is typically normal, but language skills are globally impaired. Some studies suggest deficits in visual-spatial processing and/or visual-motor integration in up to 50% of cases, but other aspects of cognitive functioning, such as memory and executive functioning, have not been well studied. Auditory working memory, however, is a consistent area of difficulty for children with LKS and appears to persist regardless of functional outcome. Behavioral disturbance is also pervasive in LKS and can sometimes be the feature requiring the most clinical attention. Recent studies have emerged that provide more thorough neurodiagnostic information about the cognitive and behavioral features of LKS, but the reported literature on expected neuropsychological findings in LKS remains sparse.

LANGUAGE ACQUISITION OF DOWN SYNDROME CHILDREN IN THE DOWN SYNDROME VILLAGE PONOROGO : A PSYCHOLINGUISTICS OVERVIEW

<p>This study focused on language acquisition of down syndrome children in the down syndrome village Ponorogo, East Java, Indonesia. The down syndrome villages are Krebet sub-district of Jambon, Sidoharjo sub-district of Jambon, Karangpatihan sub-district of Sidoharjo, Pandak sub-district of Balong, and Dayakan sub-district Badegan.</p><p> The purpose of this study were (1) to explain the first language acquisition, in both lexical and grammatical; (2) to explain the second language acquisition, both lexical and grammatical; (3) to explain the factors that affect language acquisition of down syndrome children in Ponorogo, East Java, Indonesia. The method used in this study include the data providing by interview and questionnaire; the data are analyzed descriptively by stages identifying, classifying, interpreting, and explicating.</p><p> The results showed that the down syndrome children aged 7-15 years which were being the research object, mastering the first language (mother tongue) only, it is Javanese in the <em>ngoko </em>form (the Javanese language lowest level). They do not mastered Bahasa Indonesia as the second language as well. The first language acquisition of lexical mastery are in the unique forms, including the mention of an object by a unique form, e.g. knife called <em>pangot, </em>the mention of the object based on its sound (onomatopoeic), for example ‘<em>eong’ </em>to mention cat, elimination of beginning consonants and vowels, elimination of middle consonant, consonant replacements, and others. Down syndrome children did not acquire prefix and also the repetition, did not recognize compound words, the concepts which are mastered is the here and now, the things around him, and now, it is not the past and imagination. In addition, children with Down syndrome do echolalia (imitating others), autoecholalia (repeating his own words), verbal auditory agnosia or cogenital word deafness (phonological perception problem). Some informants also impaired speech or stuttering and selective mutism (not speaking to certain situations and places)</p><p> The down syndrome children were studied experienced those cases above since their birth, although some of them had the problems because of high temperature when they were on 6 months, 1.5 years, and 2 years. Inbreeding, maternal age over 35 years, and malnutrition becomes a trigger of down syndrome. The factors that affect the first and second language acquisition are (1) the informant is rarely communicate; (2) the informant never be read bedtime stories before bed; (3) the informant had not been provided the singing before bed; (4) The lack of attention from the family toward education, especially language acquisition.</p><p> </p><strong>Key words : language acquisition, down syndrome children, psycholinguistic </strong>

From Hearing Sounds to Recognizing Phonemes: Primary Auditory Cortex is A Truly Perceptual Language Area

The aim of this article is to present a systematic review about the anatomy, function, connectivity, and functional activation of the primary auditory cortex (PAC) (Brodmann areas 41/42) when involved in language paradigms. PAC activates with a plethora of diverse basic stimuli including but not limited to tones, chords, natural sounds, consonants, and speech. Nonetheless, the PAC shows specific sensitivity to speech. Damage in the PAC is associated with so-called “pure word-deafness” (“auditory verbal agnosia”). BA41, and to a lesser extent BA42, are involved in early stages of phonological processing (phoneme recognition). Phonological processing may take place in either the right or left side, but customarily the left exerts an inhibitory tone over the right, gaining dominance in function. BA41/42 are primary auditory cortices harboring complex phoneme perception functions with asymmetrical expression, making it possible to include them as core language processing areas (Wernicke’s area).

Word deafness with preserved number word comprehension

Word deafness with preserved number word comprehension

The neural underpinnings of pure word deafness following left temporal damage

The neural underpinnings of pure word deafness following left temporal damage

Reversible pure word deafness due to inferior colliculi compression by a pineal germinoma in a young adult

We report a clinical case of a 19-year-old male patient who developed pure word deafness due to the local compressive effect of a pineal germinoma on the inferior colliculi of the quadrigeminal plate. After percutaneous radiation therapy the size of the tumor decreased significantly, while audiometry demonstrated a complete regression of the auditory deficit. Since pure word deafness is commonly attributed to temporal lesions, the inferior colliculi represent an exceptional site for these symptoms. The pathophysiological background and the scarce literature on pure word deafness, especially the one related to neoplasms of the tectal region, are briefly discussed.

Bilingualism and Bilingual Deaf Education ed. by Marc Marschark, Gladys Tang, and Harry Knoors (review)

Bilingualism and Bilingual Deaf Education, edited by Marc Marschark, Gladys Tang, and Harry Knoors (New York: Oxford University Press, 2014, 495 pp., hardcover, ISBN 978-0-19-937181-5)THIS BOOK DISCUSSES aspects of bilingualism and bilingual education that directly or indirectly affect education. It offers an overview of research on education that shows evidence of bilingualism among children, focusing on their acquisition of language and bimodal and bilingual processing. The editors state that not enough research has been done on effective education for people and on whether bilingual education could endorse Deaf education.Interestingly, in the book the word deaf is written with a small d, not with a capital D, already placing it in a position that does not assume a Deaf perspective on education. Instead, this usage of lowercase deaf indicates that the book is an aggregation of research that includes studies that use D and others that use d.The book seems to be more general in that it reflects several views of the work produced up to now that does not put forward a consensus view of education.The volume is organized in three parts: (1) a general discussion of Deaf bilingualism; (2) a focused discussion of Deaf educational issues; and (3) a more specific analysis of the bilingual setting in coenrollment environments experienced by children. Each of these three parts includes works by several authors.Part one considers various perspectives on Deaf bilingualism, especially with respect to linguistics, language issues (including bilingual acquisition and bimodal bilingualism), psychosocial development, the relationship between reading and sign language, and signed and spoken language development.The findings presented here indicate that Deaf people leverage interconnected language systems and learn how to use them in forms appropriate for their interlocutors and the relevant communication purposes of any given context. Several of the authors mentioned in this section state that it is crucial to guarantee bimodal/ bilingual development for children inasmuch as language development depends on signed and spoken language access, which will enable children to build self-identity and acquire cultural, linguistic, and cognitive skills. Cross-language interaction and coactivation are also considered, together with the effects of bilingualism on cognitive control and the consequent implications for Deaf education. Also in this first part, several authors discuss the effects of a neurolinguistic perspective, such as the possibility of producing both languages at the same time in code-blending examples from early sign language users, indicating the impact of age on neural systems. These chapters present basic research studies on the characteristics of a bilingual Deaf person.For educational purposes, a number of authors in this first section state that, although the acquisition of sign language seems to be crucial, we still have much to learn about how to design bimodal/ bilingual educational curricula. Several chapters are devoted to childrens reading development.Their authors present research findings that suggest that sign language may have a positive correlation with reading comprehension, but they also present other studies with contradictory results. For children with cochlear implants, research is presented that supports the use of a spoken language with signs cooccurring with speech as the preferred educational approach (rather than a bilingual education model).This controversy about the role of sign language again points out the inconsistency between the chapters regarding the Deaf point of view. Other research in this section presents a perspective of difference, not deficiency, claiming that language plays an important role in Deaf people s lives since they have unique linguistic-communicative experiences at home, at school, and in their general social lives. …

Pure word deafness with auditory object agnosia after bilateral lesion of the superior temporal sulcus

Based on results from functional imaging, cortex along the superior temporal sulcus (STS) has been suggested to subserve phoneme and pre-lexical speech perception. For vowel classification, both superior temporal plane (STP) and STS areas have been suggested relevant. Lesion of bilateral STS may conversely be expected to cause pure word deafness and possibly also impaired vowel classification. Here we studied a patient with bilateral STS lesions caused by ischemic strokes and relatively intact medial STPs to characterize the behavioral consequences of STS loss. The patient showed severe deficits in auditory speech perception, whereas his speech production was fluent and communication by written speech was grossly intact. Auditory-evoked fields in the STP were within normal limits on both sides, suggesting that major parts of the auditory cortex were functionally intact. Further studies showed that the patient had normal hearing thresholds and only mild disability in tests for telencephalic hearing disorder. Prominent deficits were discovered in an auditory-object classification task, where the patient performed four standard deviations below the control group. In marked contrast, performance in a vowel-classification task was intact. Auditory evoked fields showed enhanced responses for vowels compared to matched non-vowels within normal limits. Our results are consistent with the notion that cortex along STS is important for auditory speech perception, although it does not appear to be entirely speech specific. Formant analysis and single vowel classification, however, appear to be already implemented in auditory cortex on the STP.

P72 – 2355: Auditory function in patients with childhood adrenoleukodystrophy

Objective The objective of our study is to investigate auditory function in patients with childhood adrenoleukodystrophy (ALD). Methods Subjects were forty-five patients with ALD aged 2 and 11/12 years to19 yearrs. Twelve patients were asymptomatic. Tests for subjective auditory function were pure tone audiometry, verbal sound discrimination test, environmental sound discrimination test, and token test. Objective test was auditory brainstem response (ABR). Verbal auditory agnosia was defined as decreased scores of verbal sound discrimination and/or token test among patients who could respond tasks. Nonverbal agnosia was also defined as high error rate of environmental sound discrimination. Results Thirty seven patients showed normal hearing threshold and 8 patients showed elevated hearing threshold. ABR only could be performed in the youngest patient who could not perform our scheduled subjective tests. Auditory verbal agnosia was diagnosed in 10 patients. Auditory verbal and nonverbal agnosia was diagnosed in 12 patients. No patient was diagnosed as pure nonverbal agnosia. Thus 22 among 44 children showed abnormal results of subjective audiometry. Abnormal prolongation of central conduction time of brainstem was present in 15 among 45 patients. Patients who showed abnormal results in any kinds of auditory function tests were 29 among 44 patients. Conclusion Rate of abnormal auditory function in any kinds was very high (66%) compared with the previous reports. Patients with auditory agnosia have difficulty in daily living but are often misdiagnosed. Thus, to evaluate precise auditory function in patients with ALD is important. Subjective tests, especially word discrimination test is essential other than ABR and/or pure tone audiometry. The objective of our study is to investigate auditory function in patients with childhood adrenoleukodystrophy (ALD). Subjects were forty-five patients with ALD aged 2 and 11/12 years to19 yearrs. Twelve patients were asymptomatic. Tests for subjective auditory function were pure tone audiometry, verbal sound discrimination test, environmental sound discrimination test, and token test. Objective test was auditory brainstem response (ABR). Verbal auditory agnosia was defined as decreased scores of verbal sound discrimination and/or token test among patients who could respond tasks. Nonverbal agnosia was also defined as high error rate of environmental sound discrimination. Thirty seven patients showed normal hearing threshold and 8 patients showed elevated hearing threshold. ABR only could be performed in the youngest patient who could not perform our scheduled subjective tests. Auditory verbal agnosia was diagnosed in 10 patients. Auditory verbal and nonverbal agnosia was diagnosed in 12 patients. No patient was diagnosed as pure nonverbal agnosia. Thus 22 among 44 children showed abnormal results of subjective audiometry. Abnormal prolongation of central conduction time of brainstem was present in 15 among 45 patients. Patients who showed abnormal results in any kinds of auditory function tests were 29 among 44 patients. Rate of abnormal auditory function in any kinds was very high (66%) compared with the previous reports. Patients with auditory agnosia have difficulty in daily living but are often misdiagnosed. Thus, to evaluate precise auditory function in patients with ALD is important. Subjective tests, especially word discrimination test is essential other than ABR and/or pure tone audiometry.

Chapter 32 - Auditory agnosia

Auditory agnosia refers to impairments in sound perception and identification despite intact hearing, cognitive functioning, and language abilities (reading, writing, and speaking). Auditory agnosia can be general, affecting all types of sound perception, or can be (relatively) specific to a particular domain. Verbal auditory agnosia (also known as (pure) word deafness) refers to deficits specific to speech processing, environmental sound agnosia refers to difficulties confined to non-speech environmental sounds, and amusia refers to deficits confined to music. These deficits can be apperceptive, affecting basic perceptual processes, or associative, affecting the relation of a perceived auditory object to its meaning. This chapter discusses what is known about the behavioral symptoms and lesion correlates of these different types of auditory agnosia (focusing especially on verbal auditory agnosia), evidence for the role of a rapid temporal processing deficit in some aspects of auditory agnosia, and the few attempts to treat the perceptual deficits associated with auditory agnosia. A clear picture of auditory agnosia has been slow to emerge, hampered by the considerable heterogeneity in behavioral deficits, associated brain damage, and variable assessments across cases. Despite this lack of clarity, these striking deficits in complex sound processing continue to inform our understanding of auditory perception and cognition.

Norman Geschwind: career and works

Norman Geschwind was an outstanding American neurologist. He first majored in psychology and then medicine at Harvard University. After graduation, he received neurological training at Beth Israel Hospital, the National Hospital at Queen Square in London, and Boston City Hospital, under the guidance of Denny-Brown, Charles Symonds, and Fred Quadfasel. He later moved to the Boston Veterans Administration Hospital, and established the Boston University Aphasia Research Center with Edith Kaplan. This center played a cardinal role in aphasia research in the United States. In 1969, Geschwind became a Professor at Harvard Medical School. Disconnection syndromes, which made Geschwind's name famous worldwide in the field of neurology, are reviewed here in regard to pure alexia, conduction aphasia, pure word deafness, isolation of the speech area, and apraxia, with reference to the Wernicke-Geschwind model. Other contributions by Geschwind are also described, such as behavioral changes in temporal lobe epilepsy (Geschwind syndrome) and cerebral lateralization, including the Geschwind-Galaburda hypothesis.

Encephalopathy with status epilepticus during sleep: Unusual EEG patterns

PurposeTo retrospectively analyze the electroclinical characteristics, etiology, treatment, and prognosis of patients with epileptic encephalopathy with status epilepticus during sleep (ESES) with unusual EEG features and to corroborate if this series of patients is part of the ESES syndrome. MethodCharts of 17 patients with typical clinical manifestations of the ESES syndrome with focal ESES of non-REM sleep at onset and during the focal ESES phase, or bilateral synchronic and asynchronic ESES with a symmetric or asymmetric morphology, continuous or subcontinuous and sometimes multifocal paroxysms with or without slow-wave activity during slow sleep seen between 2000 and 2012 were analyzed. ResultsMean patient follow-up from onset was 7.5 years. An idiopathic cause was found in seven patients, a structural cause in eight, and etiology was unknown in the remaining two. The median age at onset of the unusual ESES syndrome was 7 years. During the ESES phase, 15 children developed new seizure types, negative myoclonus was observed in seven patients, positive myoclonus in five, and absences in nine. Six patients had motor impairment, two had auditory verbal agnosia, and two had motor speech impairment. Attention deficit hyperactivity disorder was observed in four, aggressiveness in six, memory deficit in two, and impaired temporospatial orientation in four.The patients with focal ESES in the frontal region showed behavioral disturbances and/or motor deterioration, and in those with temporo-occipital involvement the dominant clinical manifestations were language and/or behavioral disturbances. ConclusionOur patients with typical clinical manifestations of ESES syndrome but with unusual EEG patterns may be variants of this syndrome.

Episodic Epileptic Verbal Auditory Agnosia in Landau Kleffner Syndrome Treated With Combination Diazepam and Corticosteroids

We report 2 pediatric patients who presented initially with seizures followed by subacute language regression characterized by a verbal auditory agnosia. These previously normal children had no evidence of expressive aphasia during their symptomatic periods. Further, in both cases, auditory agnosia was associated with sleep-activated electroencephalographic (EEG) epileptiform activity, consistent with Landau-Kleffner syndrome. However, both cases are unique since the episodic auditory agnosia and sleep-activated EEG epileptiform activity rapidly responded to combination therapy with pulse benzodiazepine and corticosteroids. Further, in each case, recurrences were characterized by similar symptoms, EEG findings, and beneficial responses to the pulse benzodiazepine and corticosteroid therapy. These observations suggest that pulse combination high-dose corticosteroid and benzodiazepine therapy may be especially effective in Landau-Kleffner syndrome.

Auditory dysfunction in patients with cerebrovascular disease.

Auditory dysfunction is a common clinical symptom that can induce profound effects on the quality of life of those affected. Cerebrovascular disease (CVD) is the most prevalent neurological disorder today, but it has generally been considered a rare cause of auditory dysfunction. However, a substantial proportion of patients with stroke might have auditory dysfunction that has been underestimated due to difficulties with evaluation. The present study reviews relationships between auditory dysfunction and types of CVD including cerebral infarction, intracerebral hemorrhage, subarachnoid hemorrhage, cerebrovascular malformation, moyamoya disease, and superficial siderosis. Recent advances in the etiology, anatomy, and strategies to diagnose and treat these conditions are described. The numbers of patients with CVD accompanied by auditory dysfunction will increase as the population ages. Cerebrovascular diseases often include the auditory system, resulting in various types of auditory dysfunctions, such as unilateral or bilateral deafness, cortical deafness, pure word deafness, auditory agnosia, and auditory hallucinations, some of which are subtle and can only be detected by precise psychoacoustic and electrophysiological testing. The contribution of CVD to auditory dysfunction needs to be understood because CVD can be fatal if overlooked.

The neural basis for writing from dictation in the temporoparietal cortex

Cortical electrical stimulation mapping was used to study neural substrates of the function of writing in the temporoparietal cortex. We identified the sites involved in oral language (sentence reading and naming) and writing from dictation, in order to spare these areas during removal of brain tumours in 30 patients (23 in the left, and 7 in the right hemisphere). Electrostimulation of the cortex impaired writing ability in 62 restricted cortical areas (.25 cm2). These were found in left temporoparietal lobes and were mostly located along the superior temporal gyrus (Brodmann's areas 22 and 42). Stimulation of right temporoparietal lobes in right-handed patients produced no writing impairments. However there was a high variability of location between individuals. Stimulation resulted in combined symptoms (affecting oral language and writing) in fourteen patients, whereas in eight other patients, stimulation-induced pure agraphia symptoms with no oral language disturbance in twelve of the identified areas. Each detected area affected writing in a different way. We detected the various different stages of the auditory-to-motor pathway of writing from dictation: either through comprehension of the dictated sentences (word deafness areas), lexico-semantic retrieval, or phonologic processing. In group analysis, barycentres of all different types of writing interferences reveal a hierarchical functional organization along the superior temporal gyrus from initial word recognition to lexico-semantic and phonologic processes along the ventral and the dorsal comprehension pathways, supporting the previously described auditory-to-motor process. The left posterior Sylvian region supports different aspects of writing function that are extremely specialized and localized, sometimes being segregated in a way that could account for the occurrence of pure agraphia that has long-been described in cases of damage to this region.

Landau–Kleffner syndrome: A study of 29 patients

PurposeThe aim of the study was to retrospectively analyze the electroclinical features, etiology, treatment, and prognosis of 29 patients with Landau–Kleffner syndrome (LKS) with a long-term follow-up. MethodsInclusion criteria were a diagnosis of LKS with: (1) acquired aphasia or verbal auditory aphasia; (2) with or without focal seizures, secondarily generalized tonic-clonic seizures, absences, or atonic seizures. ResultsMean follow-up was 12 years. All cases except six had seizures. Before the onset of aphasia, developmental language and behavioral disturbances were present in 19 and 14 patients, respectively. All patients had verbal auditory agnosia. Aphasia was severe in 24 patients and moderate in five. Nonlinguistic cognitive dysfunctions were moderate in 14 patients. Behavioral disturbances were found in 16 patients. During the continuous spike-and-wave discharges during slow sleep phase, the spike-wave index was >85% in 15, 50–85% in eight, and 30–50% in four. In two patients, the EEG recording showed occasional bilateral spikes, without continuous spike-and-wave discharges during slow sleep. In this phase, the awake EEG recording showed more frequent interictal abnormalities, predominantly in the temporal regions. Eight patients recovered language completely, but the remaining patients continue to have language deficits of different degrees. ConclusionLandau–Kleffner syndrome is an epileptic encephalopathy characterized by acquired verbal auditory aphasia and seizures in most of the patients associated with continuous or almost continuous spike-and-wave discharges during slow wave sleep. The most commonly used treatments were clobazam, ethosuximide, sulthiame. High-dose steroids were also administered. Adequate and early management may avoid language and cognitive deterioration.

Partly reversible central auditory dysfunction induced by cerebral vasospasm after subarachnoid hemorrhage

The authors describe a rare case of central auditory dysfunction induced by cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). A 55-year-old woman who was admitted after aneurysmal SAH developed cerebral vasospasm on Day 3 affecting mainly the right middle cerebral artery (MCA) and partly the left MCA. The vasospasm became refractory to conventional therapy and was ultimately improved by intraarterial infusion of nimodipine in the right MCA and angioplasty. Severe auditory dysfunction was apparent from Day 10 as the patient was not reactive to speech or environmental sounds. Brain MRI on Day 17 demonstrated infarcted areas mainly in the right hippocampus, medial occipital lobe, and thalamus. The patient underwent further examination using audiometry, speech testing, auditory evoked potentials, functional MRI, and cerebral PET. The initial diagnosis was extended nonverbal agnosia and total pure word deafness. The central auditory dysfunction improved over 6 months, with persisting hyperacusis, tinnitus, and amusia. Central auditory dysfunction is a rare complication after SAH. While cortical deafness may be associated with bilateral lesions of the temporal cortex, partly reversible central auditory dysfunction was observed in this patient after prominently unilateral right temporal lesions. The role of the interthalamic connections can be discussed, as well as the possibility that a less severe vasospasm on the left MCA could have transiently impaired the left thalamocortical auditory pathways.

16. Electrical status epilepticus in «slow wave» sleep and Landau–Klefner syndrome

Electrical status epilepticus in non-REM (without rapid eye-movements) sleep (ESES) and Landau–Kleffner syndrome (LKS) is rare epileptic encephalopathies occurring during childhood. ESES is defined by the EEG criterion, namely >85% time of non-REM sleep is occupied with bilateral continuous 1–3 Hz spike-waves (BCSWS). ESES is the only epileptic syndrome requiring the sleep EEG study to establish and follow-up the BCSWS. Main clinical syndromes related with the ESES/BCSWS are: atypical benign epilepsy with centro-temporal spikes (ABECTS), LKS, and opercular syndrome. LKS is characterized by verbal auditory agnosia as its typical aphasia, epileptiform EEG abnormalities and seizures. ESES occurs in 30–50% of patients. Clinical evolution of ESES is characterized by an active phase with BCSWS followed by the recovery phase when the patient is seizure-free but cognitive dysfunctions and behavioral disorders persist. The importance of early diagnosis and treatment initiation is stressed by clinical experience that neuropsychological sequelae cannot be resolved if a persistent active phase lasts for over 2 to 3 years. In our series of patients with ESES and LKS, EEG becomes normalized in both LKS and the ESES related to ABECTS, at latest during the puberty. However, some degree of cognitive or behavioral disorders is often persistent in adulthood.

The Spectrum of Aphasia Subtypes and Etiology in Subacute Stroke

Aphasia is one of the most common stroke syndrome presentations, yet little is known about the spectrum of different subtypes or their stroke mechanisms. Yet, subtypes and etiology are known to influence the prognosis and recovery. Our aim is to analyze aphasia subtypes and etiology in a large subacute stroke population. Consecutive patients from a dedicated cognitive stroke registry were accrued. A validated cognitive screening examination was administered during the first month of stroke presentation, which enabled a diagnosis of 14 different aphasic subtypes. The evolution from one subtype to another in the acute and subacute period, at times, resulted in more than 1 subtype being diagnosed. Etiology of stroke was determined by the modified Trial of Org 10172 in Acute Stroke Treatment criteria that included intracerebral hemorrhage. Exclusions included dementia, chronic medical illness, substance abuse, and severe depression. Of 2389 stroke patients, after exclusions (n=593), aphasias numbered 625 (625 of 1796; 34.8%), and the subtype frequencies included Broca aphasia (n=170; 27.2%), anomic aphasia (n=165; 26.4%), global aphasia (n=119; 19.04%), and subcortical aphasia (n=57; 9.12%). Less frequent subtypes (total n=40; 6.7%) included transcortical aphasia (n=11), Wernicke aphasia (n=10), conduction aphasia (n=7), aphemia (n=3), semantic aphasia (n=3), crossed aphasia (n=3), pure word deafness (n=2), and foreign accent syndrome (n=1). Aphasia subtypes and etiologies had some significant associations (chi-square: 855.8, P value<.0001). Bonferroni-adjusted P values revealed that anomic aphasia had a significant association with small-vessel disease (SVD) (odds ratio [OR]=2.0254, 95% confidence interval [CI]: 1.3820-2.9681), and global aphasia patients mostly had cardioembolic (CE) causes (OR=2.3589, 95% CI: 1.5506-3.5885) and less likely SVD (OR=.2583, 95% CI: .1444-.4654). Other notable inferences were included. Wernicke aphasia was caused by either CE (6 of 12; 50%) or hemorrhage (4 of 12; 33.3%) in a combined 83% of cases. Subcortical aphasia was because of SVD in 36% (31 of 85) or because of hemorrhage in 32% (27 of 85) yielding a combined 68% of cases. Sixty percent of transcortical aphasias as a group were because of either large-vessel disease (7 of 20; 35%) or hemorrhage (5 of 20; 25%). Alternatively, a diagnosis of Broca aphasia could be because of any of the etiological categories. (1) Aphasias are a heterogeneous entity in subtype and etiology; (2) Broca, global, anomic, and subcortical aphasias accounted for the vast majority of aphasia subtypes; (3) SVD, cardioembolism, and hemorrhage are significantly associated with certain signature aphasic syndromes; and (4) determination of aphasia subtype can assist with etiology, prognosis, influence aphasia therapy, and provide the basis for future randomized controlled trials with pharmacological therapy or behavioral therapy.