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PurposeA summary of literature surrounding cortical hearing impairment (cortical deafness, auditory agnosia, and pure word deafness) was studied to identify causes and prognoses of the disorders, in addition to assessment methods and rehabilitation strategies for the multidisciplinary care team setting.MethodA comprehensive review of the literature surrounding cortical hearing impairment with a focus on clinical evaluation and management of patients with these conditions was performed.ResultsAn extensive literature search resulted in 109 relevant articles discussing cases of cortical hearing impairment.ConclusionsCortical deafness continues to be the rarest of the cortical hearing impairment spectrum of disorders, with reports of auditory agnosia and pure word deafness appearing more commonly. In order to assess and manage patients with these conditions, audiologists must utilize a comprehensive set of clinical tools. This information must be combined with results of thorough multidisciplinary evaluations in order to better characterize diagnoses and outcomes for these patients. Continued reporting of case studies and summaries of the literature is encouraged, with a specific call for more consistent assessment and reporting formats.

Pure word deafness is a rare neurological disorder linked with an inability to comprehend speech. The precise localization of damage is still unclear.A 72-year-old woman presented with acute verbal contact disturbances, disorientation, and anxiety. In the neurological examination a slight right hemiparesis was found, together with a pure word deafness (PWD) in neuropsychological tests. Neuroimages confirmed bilateral ischemic lesions in the superior temporal gyrus (STG) acute in the left hemisphere.Our case suggested that bilateral, symmetric lesions in the region of STG could cause pure world deafness. The diversity and severity of symptoms confirm the necessity of pure world deafness classification for subtypes.

This chapter summarizes early computed tomography (CT) scan studies in stroke patients with aphasia from the 1970s through the 1990s. Studies took place at the Boston University Aphasia Research Center located at the Boston Veterans Affairs Medical Center. Earliest studies associated classical aphasia syndromes with lesions located in cortical language areas on CT scans. In the 1980s, studies reported that chronic aphasia could be associated with subcortical lesion only; emphasis was on lesion in white matter pathways. In the 1990s, studies showed that lesion sites on CT scans performed after 2 months poststroke could be predictive for recovery of auditory language comprehension, and meaningful nonfluent speech at 1 year poststroke. Lesion site patterns were identified for different outcome levels following specific language therapy programs. Some rare aphasia cases are included: left-handers with separate hemispheric dominance locations for speech versus comprehension in the same person; and a unilateral, word deafness case.

Pure word deafness (PWD), or auditory verbal agnosia, is characterized by the inability to understand or repeat spoken language, sparing the discrimination and recognition of environmental sounds, speaking, reading and writing. Because of its rarity and the variety of its possible aetiologies, PWD remains an incompletely understood condition. We report the unique case of a patient developing PWD after surgical resection of a Vein of Galen aneurysm and arteriovenous malformation (VOGA). Clinical and surgical details are presented. Aetiology and pathophysiologic features of PWD in this specific case are discussed and the literature is reviewed.

Extrapontine myelinolysis and pure word deafness are very uncommon disorders. Here, we report a case of a 19-year-old woman who suffered from osmotic demyelination syndrome with coincidence of typical pure word deafness. As a consequence of rapid correction of hyponatremia, the patient demonstrated an initial onset of cortical deafness, and then progressed to generalized auditory agnosia, which eventually developed into confined verbal auditory agnosia (pure word deafness). Bilateral extrapontine myelinolysis was confirmed using brain magnetic resonance imaging. This case suggests that verbal and nonverbal stimuli may involve separate thalamocortical pathways.

To assess the role of inferior colliculi as a generator of Wave V of brainstem auditory evoked potentials and in modulating the olivocochlear efferent auditory system.Case review.University and tertiary referral centers.Case report of a patient with word deafness caused by mesencephalic hemorrhage according to audiologic and electrophysiologic findings.The patient is a 48-year-old woman who suffered word deafness caused by hemorrhage localized at the quadrigeminal plate (including the inferior colliculi). At a follow-up visit, her pure-tone audiogram revealed symmetric severe sensorineural hearing loss that had partially resolved, whereas speech audiometry showed persistent word deafness. Acoustic reflexes were elicited, with normal thresholds bilaterally. Transient evoked otoacoustic emissions were recorded from both ears, with normal response and signal-to-noise ratio, but there was a failure for their amplitude to be suppressed with contralateral sound stimulation. Brainstem auditory evoked potentials were of normal amplitude and latencies bilaterally.The finding of normal brainstem auditory evoked potentials supports the view that the neural generator of Wave V lies caudally to the inferior colliculi. Moreover, the abnormal suppression of transient evoked otoacoustic emissions indicates that descending collicular input is capable of modulating levels of excitability within the olivary nucleus and the cochlea.

We describe a 31-year-old, right-handed man who exhibited pure word deafness (PWD) due to a localization-related seizure. The patient was suddenly unable to comprehend spoken words, whereas he had no difficulty in speaking, comprehending written language, or discriminating non-verbal sounds. Diffusion-weighted imaging and fluid-attenuated inversion recovery on brain magnetic resonance imaging revealed hyperintense lesions in the left superior temporal gyrus (STG) and left superior marginal gyrus (SMG). Furthermore, brain single-photon emission computed tomography showed that these lesions were hyperperfused. An electroencephalogram (EEG) showed multiple spike-and-slow-wave complexes spreading to the left temporal regions. Immediately after administering midazolam intravenously, the patient was able to comprehend spoken words, and the epileptiform discharges in the left temporal regions disappeared. These findings indicate that he suffered from PWD resulting from a dysfunction of the left hemisphere alone. Furthermore, they suggest that the left STG and left SMG play an important role in the recognition of spoken words.

In this paper some of Benson's ideas about the role of the insula in language are developed. It is proposed that the insula is involved in two di erent aspects of language. On one hand, the insula should be regarded as a part of the brain language area. Damage to the insula frequently results in aphasia. Among the various language disturbances associated with damage in the left insula are Broca's aphasia, conduction aphasia, and the word deafness component of Wernicke's aphasia. Apraxia of speech and mutism have been also reported associated with insula damage. Then on the other hand, recent studies of anatomical connections of the insula point to an important viscero limbic role and it has been suggested that the insula may influence verbal motivation and verbal affect.

A 66-year-old right-handed man developed pure anarthria following pure word deafness. In addition to language disorders, his behavior gradually changed and finally included violence against his wife. Brain magnetic resonance imagings revealed atrophy of the left perisylvian area, which included the inferior half of the precentral gyrus and the upper portion of the superior temporal gyrus, consistent with frontotemporal dementia (FTD). It has been documented as either a disorder of expressive language or as an impaired understanding of word meaning. Unlike with pure anarthria, pure word deafness is not included in the clinical diagnostic current criteria for FTD. However, a large variety of language symptoms can appear in FTD according to the distribution of pathological changes in the frontotemporal cortices. This case suggests that pure word deafness could be a prodomal symptom of FTD.

This article examines four disorders of auditory processing that can result from selective brain damage (cortical deafness, pure word deafness, auditory agnosia and phonagnosia) in an effort to derive a plausible functional and neuroanatomical model of audition. The article begins by identifying three possible reasons why models of auditory processing have been slower to emerge than models of visual processing: neuroanatomical differences between the visual and auditory systems, terminological confusions relating to auditory processing disorders, and technical factors that have made auditory stimuli more difficult to study than visual stimuli. The four auditory disorders are then reviewed and current theories of auditory processing considered. Taken together, these disorders suggest a modular architecture analogous to models of visual processing that have been derived from studying neurological patients. Ideas for future research to test modular theory more fully are presented.

We describe a 57 year old, right handed, English speaking man initially diagnosed with progressive aphasia. Language assessment revealed inconsistent performance in key areas. Expressive language was reduced to a few short, perseverative phrases. Speech was severely apraxic. Primary modes of communication included gesture, pointing, gaze, physical touch and leading. Responses were 100% accurate when he was provided with written words, with random or inaccurate responses for strictly auditory/verbal input. When instructions to subsequent neuropsychological tests were written instead of spoken, performance improved markedly. A comprehensive audiology assessment revealed no hearing impairment. Neuroimaging was unremarkable. Neurobehavioral evaluation utilizing written input led to diagnoses of word deafness and frontotemporal dementia, resulting in very different management. We highlight the need for alternative modes of language input for assessment and treatment of patients with language comprehension symptoms.

Case IJ shows impaired capacity to repeat individual words despite normal hearing as measured by audiometry and timpanometry. She also has difficulty in identifying other environmental sounds. Her phonological memory span for visually-presented material is normal, and her memory span for spoken digits is only slightly impaired. It is suggested that she has a pre-phonological auditory processing deficit; the implications of this for discussion of the role of phonological short-term memory in language processing are discussed.

Individuals with aphasia have more problems detecting small differences between speech sounds than larger ones. This paper reports how phonemic processing is impaired and how this is influenced by speechreading. A non-word discrimination task was carried out with 'audiovisual', 'auditory only' and 'visual only' stimulus display. Subjects had to decide whether two presented stimuli were the same. Six aphasic subjects with speech sound processing difficulties and 14 non-brain-damaged control subjects participated in this study. It was found that the aphasic subjects have difficulties in discriminating pairs of non-words, which are more profound for small differences. Differences in 'voicing' were least often detected and therefore seem most difficult to perceive. This implies different processing of the phonetic dimensions in speech sound perception. Performance improved when speechreading was possible. As this improvement is not based on differences in place of articulation only, theories of audiovisual processing need to be revised.

Evidence has accumulated that posterior superior temporal sulcus (STS) is critically involved in phonological processing during speech perception, although there are conflicting accounts regarding the degree of lateralization. The current fMRI experiment aimed to identify phonological processing during speech perception through repetition-suppression effects. Repetition-suppression occurs when brain activity decreases from repetitive presentation of stimulus characteristics, in regions of cortex that process those characteristics. We manipulated the degree of phonological repetition among words in short lists to obtain systematic decreases in brain response, indicative of phonological processing. The fMRI experiment presented seventeen participants with recorded wordlists, of low, medium, or high phonological repetition, defined by how many phonemes were shared among words. Bilaterally, middle STS demonstrated activity differences consistent with our prediction of repetition-suppression, as responses decreased systematically with each increase in phonological repetition. Phonological repetition-suppression in bilateral STS converges with neuroimaging evidence for phonological processing, and word deafness resulting from bilateral superior temporal lesions.

Pure word deafness is a rare disorder dramatically impairing comprehension of spoken language, while auditory functions remain relatively intact. We present a 71-year-old woman with a slowly progressive disturbance of speech perception due to pure word deafness. MRI revealed degeneration of the temporal lobes. A magnetoencephalographic investigation using alternating single tone stimulation showed that N100 was followed by a second transient response and was abnormally prolonged up to 600–700 ms. We conclude that auditory processing is disturbed at long latency ranges following the N100, which may result in the clinical presentation of pure word deafness.

頭部外傷により語聾を伴った重度感覚失語の１例に，発症２年から７年目まで言語治療を行いその成績を検討した。症例は発症時34歳，右利きの男性である。転落による脳挫傷で血腫除去術を受けた。ＣＴでは左上中側頭回と中前頭回領域を中心とした低吸収域と水頭症を認めた。発症後２年目から３年目までは，読話を併用しての単語，音節の聞き取り練習を行った。その結果，読話を併用した単語の聴認は20％から85％まで改善した。聴覚だけによる聞き取りは0％から約40％に向上した。次に喚語困難の改善を目標に書字訓練を行った。その結果，喚語困難は７％から約90％へと著しい改善を示した。本例の経過から，自然治癒期間を過ぎたと思われる語聾であっても長期的には質的な改善を示す場合があることと，失語を伴った語聾でも訓練によって読話能力や喚語困難が改善する例のあることがわかった。以上より，症例によっては長期にわたる言語治療の必要性を強調した。

This report describes a 25-year-old man with acute head trauma and brain damage resulting in pure word deafness. Bilateral temporal lobe pathology was confirmed by brain imaging and functional brain studies. A brief discussion about the difference between pure word deafness and other aphasias, as well as anatomic correlation is provided.

AL, a woman with an acquired disturbance of auditory processing beginning in the second decade, was originally diagnosed as having pure word deafness. Recent analysis with a wide range of stimuli suggests that her comprehension deficit also extends to a subset of musical and non-verbal environmental sounds. The perceptual demands of the different auditory stimuli appear to account for part of the apparent material specificity. Additionally, over the years, the presumed temporal lobe cortical pathology has been supplemented by a mild to moderate, peripheral low-frequency hearing loss and evidence of dysfunction in lower level auditory processing pathways. The current peripheral dysfunction closely resembles cases recently labeled as auditory neuropathy. The diagnosis of pure word deafness should not be based on a limited set of auditory stimuli; additionally, a careful assessment using modern audiological techniques should be performed to evaluate peripheral auditory functions.

We report two patients with pure word deafness (PWD) with tumour in the III ventricle region with obstructive hydrocephalus. A diagnosis of PWD was made in these two patients in view of impaired verbal comprehension in the presence of adequate hearing, intact acoustic stapedius reflex and well preserved environmental sound perception. Return of verbal comprehension following the radiation therapy observed is probably due to the reduction of the tumour mass and the release of thalamocortical auditory pathways from its compressive effect. Our findings support the hypothesis of the presence of discrete auditory pathways for mediation of verbal and non-verbal stimuli independently.

A long-term study of auditory disturbance of a female case who had suffered from pure word deafness associated with Landau-Kleffner syndrome was reported. The patient developed this syndrome at age 4, and we continued the follow-up until she reached 20. The following became clear after the investigation: (1) even by the age of 20 her auditory defect had not improved significantly; (2) from an early stage she could not identify either vowels or consonant-vowel syllables; (3) later she had no difficulty identifying vowels, but her consonant-discrimination score hardly improved; and (4) her problem in consonant identification was unique in that she could discriminate between the voiced and voiceless group but had great difficulty identifying the consonants within each group. These findings led to the conclusion that the patient is unable to recognize short time duration consonants due to an insensibility to loudness and a defect in temporal resolution.

The spectrum of higher cortical hearing problems in patients with frontotemporal dementia is discussed.

Perception of speech is effortless under most circumstances; this may explain why the complexity of this cognitive process is so often unappreciated. While most other sounds in the environment are acoustically very distinctive, the 30 or 40 speech sounds people make are discriminable only by rapid analysis of rather subtle acoustic cues. Given the importance of language, it seems plausible not only that our auditory system evolved a degree of specialization for handling such analyses, but also that this specialization should assimilate substantial neural resources. Recent work in comparative physiology and human brain imaging suggests, in fact, that much of the superior temporal gyrus in humans is devoted to this perceptual feat.

FROM THE confusing mass of clinical symptoms displayed by patients with disorders of the speech mechanism, neurologists have been fairly well agreed on isolating "sensory aphasia" as a well-defined syndrome. As described by Wernicke, 1 this aphasia, which is now known by his name, consists of loss of comprehension of spoken language and loss of ability to write and read (silently), with power of articulate speech retained but distorted in that words and syllables are misplaced and mispronounced—paraphasia. Lichtheim 2 first described a different syndrome, in which the inability to understand spoken words was an isolated deficit—unaccompanied by distortion of spontaneous speech or by severe disturbance in writing or understanding the printed word. 3 Such a condition has been called "pure word deafness"; Wernicke, who thought that the phenomenon was correlated with a defect in conduction through subcortical layers of the temporal lobe from Heschl's gyrus to Area 42, stated