Auditory agnosia restricted to environmental sounds following cortical deafness and generalized auditory agnosia

We encountered a case of auditory agnosia restricted to environmental sounds, which was associated with the development of bilateral subcortical lesions after suffering a bilateral putaminal hemorrhage. The patient had a history of a putaminal hemorrhage on her left side without any major disability. Three years later, she suffered a putaminal hemorrhage on the other side. The clinical picture started with cortical deafness, then changed to generalized auditory agnosia for verbal and environmental sounds, and finally developed into auditory agnosia confined to the perception of environmental sounds. Her errors in a test of sound recognition were discriminative rather than associative in nature. Neuro-radiological examinations revealed bilateral subcortical lesions involving the fibers from the medial geniculate body to the temporal lobes after bilateral putaminal hemorrhage. This case suggested that the subcortical lesion involving bilateral acoustic radiation could cause either cortical deafness, auditory agnosia of all sounds, or auditory agnosia restricted to environmental sounds.     

Dysprosody associated with environmental auditory sound agnosia in right temporal lobe hypoperfusion--a case report]

A 60-year-old right-handed man showed dysprosody and agnosia for environmental sounds. His mother tongue was Japanese, and he could not speak foreign languages. He gradually developed difficulty in speaking from the age of 57 years, speaking non-native Japanese. In addition, he often complained of difficulty in hearing sounds, but audiometry showed no abnormalities. At the age of 60 years, the standard language test of aphasia showed no abnormalities in repetition, verbal comprehension, or reading, suggesting the absence of aphasia. However, in speaking, marked abnormality in rhythm, and occasional lack of postpositional particles and syllable-stumblings were observed. Writing was almost accurate, but a few grammatical errors were observed in speaking were observed. There were no cerebellar symptoms, pyramidal signs, pathologic reflexes, or abnormalities in phonation-related organs. Though the recognition of verbal sounds was maintained, impairment in the recognition of non-verbal sounds was observed. An environmental sound perception test showed correct answers only in 8 of 21 non-verbal sound sources (such as a car starting, glass breaking and so on), suggesting agnosia for environmental sounds. He insisted that the difficulty in perception was due to hearing impairment. However, re-examination with an increase in the sound volume showed similar results. He had no inconvenience in daily life and was not aware of agnosia for environmental sounds. He could recognize and differentiate sounds he heard once. His intelligence was normal, and neither apraxia nor frontal lobe symptoms were observed. MRI of the brain revealed slight atrophy of the right temporal lobe. Cerebral blood flow SPECT showed decreased blood flow from the superior temporal gyrus to the area around the arcuate fasciculi in the right temporal lobe. We considered that the lesion responsible for environmental auditory sound agnosia was present in the area around the secondary auditory area of the right temporal lobe and this patient differed from slowly progressive aphasia characterized by decreased blood flow in the left temporal lobe. Although the pathological process occurring in the area of hypoperfusion remained unclear, early stage of some degenerative disorders was more likely than cerebrovascular disease.     

Diffusion-weighted MRI predicts prognosis in severe hypoglycemic encephalopathy.

A 20-year-old woman presented unconscious due to hypoglycemia after a self-administered insulin injection. Diffusion-weighted MRI (DWI), performed 5 days after admission, demonstrated heterogeneous high-intensity signal areas in both the cortex and subcortex but sparing the motor and sensory centers. On the 11th day after admission, she began making incomprehensible verbal sounds, eye opening spontaneously and moving her extremities with pyramidal tract signs. Three months later, she had aphasia, agnosia and apraxia but a normal gait without pyramidal tract signs or ataxia. DWI is thus considered useful to predict the functional outcome of patients with severe hypoglycemia.     

Motor amusia following a right temporal lobe hemorrhage--a case report

A 65-year-old female was admitted to our hospital because of left hemiparesis with sudden onset one week before. She was congenitally right-handed. She had been a teacher of Japanese string instrument (samisen) playing and been able to sing Japanese traditional songs well. A tape on which she had recorded her songs one year before the admission also proved her to be a good singer. Neurological examination on admission revealed almost normal findings except for minimal weakness in her left hand fingers. Right temporal lobe hemorrhage was revealed by CT scan. One month after the admission, she complained that she was unable to sing her songs and to play samisen as she used to do. Her intelligence was normal (WAIS VIQ116, PIQ108) and there were no abnormal findings as follows: aprosodia, aphasia, agraphia, memory disturbance, agnosia and ideational, ideomotor, constructional or limb-kinetic apraxia. She could point out her errors while singing. However, musical receptive function was slightly disturbed with tonal memory in Seashore test. When she was asked to sing a song without any instrumental support, she hummed a melody occasionally with wrong pitch, but rhythmically. After hearing a song she knew well, she reproduced it with slight improvement. With the vocal or the instrumental accompaniment, she could sing fairly well. She had some mistakes of pitch while playing a samisen. MRI was performed one year and a half after the brain hemorrhage. It displayed a thin linear of hematoma in the white matter of the right upper temporal and transverse gyrus. It was proved in our case that motor amusia with minimal musical receptive dysfunction could appear following a cerebral lesion and musical function might be independent of intelligence or verbal function.     

Clinical and audiological findings in a case of auditory agnosia

Summary A case is reported of severe agnosia for verbal and non-verbal sounds without associated aphasic disorder. A CT scan revealed bilateral, temporal lobe lesions from two ischaemic accidents that had occurred 9 months apart. The search for subtle deficits in this patient showed normal sensitivity to changes in the intensity and frequency of simple sounds; in contrast, his ability to discriminate sound duration and musical note sequences was severely impaired. The simultaneous recording of the whole auditory-evoked response pattern revealed no abnormality in the early components, which reflect the activation of the auditory nuclei and pathways of the brain stem. However, the middle and late components were delayed and slowed. These results and others in the literature suggest that the neocortex in man, as in other mammals, plays an essential role in the temporal aspects of hearing. Also, the two main ingredients commonly recognized in auditory agnosia, i.e. word deafness and the inability to interpret non-verbal sounds, are caused by the disruption of elementary, bilaterally represented cortical functions which start the processing of every kind of auditory information.     

A case of auditory agnosia with the lesion of bilateral auditory radiation

A 53-year-old man showed central auditory disturbance with recurrent cerebral hemorrhage. At his acute stage he had deafness and auditory anosognosia. Two or three months later, there was no deafness and auditory anosognosia, but he could not comprehend words, environmental sounds and music. Auditory brainstem responses showed no peripheral or brainstem damage, and the lesion of bilateral auditory radiation was detected by MRI. His auditory agnosia did not improve over one and a half year. There is no report like such permanent auditory agnosia with the lesion of bilateral subcortical temporal lobe.     

"Deaf hearing": unacknowledged detection of auditory stimuli in a patient with cerebral deafness

We describe a patient with the rare disorder of total deafness caused by a bilateral lesion in the temporal lobes and lesions in the central pontine area. Although she displayed no voluntary ability to detect or localize or identify sounds and denied hearing them when asked in writing, she retained some ability to respond reflexively to sounds. When attempts were made to restore awareness of sounds and/or voluntary responses to sounds by drawing her attention to her appropriate orienting head movements her performance improved and she began to respond successfully in a "forced-choice" paradigm. However, even when she became confident at detecting and localizing sounds she remained densely agnosic to their meaning. Her condition of deaf-hearing bears many similarities to that of blindsight.     

Auditory agnosia with relative sparing of speech perception

We report a case of auditory agnosia in which the initial clinical picture began with generalized auditory agnosia for verbal and non verbal sounds, but rapidly changed to a selective auditory agnosia confined to the perception of non verbal sounds. CT scanning and MRI did not demonstrate cortical or subcortical damage, except for bilateral ventricular enlargement. The patient was submitted to audiological investigations including physical and psychoacoustic studies. Deficits were revealed during the decay and loudness discrimination test, but no temporal auditory acuity deficit was observed. The results of these studies are discussed in relation to the clinical picture. Also the dissociation between verbal perception and non verbal perception is discussed.     

Role of cognitive control in language deficits in different types of aphasia

ABSTRACT

Background: Although studies show that different facets of cognitive control are impaired in persons with aphasia (PWA), the question how they impact language abilities in different types of aphasia remains open.

Aims: Following the hypothesis that diminished attention contributes to language impairments in aphasia, we predicted that both fluent and non-fluent PWA would perform worse than neurologically intact individuals on verbal and non-verbal cognitive control tasks. Also, testing the view that linguistic disturbances in fluent and non-fluent PWA dissociate, we predicted differential relationships in performance on cognitive control tasks and language impairment.

Methods & Procedures: Fluent PWA (N = 17) and non-fluent PWA (N = 14) were compared to unimpaired speakers (N = 21) on the non-verbal Flanker task tapping domain-general cognitive control, and Stroop task measuring verbal cognitive control, as well as subtests from the Russian version of the Birmingham Cognitive Screen, namely the Auditory Control task tapping verbal cognitive control and the Rule Finding task measuring domain-general cognitive control. All PWA completed picture naming and language comprehension tasks.

Outcomes & Results: All PWA were more impaired on the Stroop and Auditory Control tasks, with no impairment on the non-verbal Flanker task compared to the controls. Non-fluent PWA also performed significantly worse on the Rule Finding that requires forming and updating non-verbal relational representations. Differences between aphasia groups were found on the Auditory Control task only, where non-fluent PWA were more vulnerable to task demands. Correlation analyses found that verbal and non-verbal cognitive control performance was correlated for the non-fluent group, whereas only correlations between verbal cognitive control tasks were significant for the fluent group. For all PWA, non-verbal cognitive control indexed by Flanker interference scores was related to language comprehension, whereas verbal cognitive control was related to picture naming. However, non-verbal relational reasoning as indexed by the Rule Finding task was significantly related to language comprehension in the non-fluent group only.

Conclusions: All PWA had diminished verbal cognitive control. Non-fluent PWA demonstrated higher vulnerability to domain-general cognitive control deficits compared to fluent PWA. Performance on verbal and non-verbal cognitive control tasks significantly overlapped in the non-fluent group only. Both groups recruited non-verbal cognitive control during language comprehension and verbal cognitive control during picture naming. Only non-fluent PWA relied on domain-general relational reasoning during language comprehension. These findings reinforce the importance of cognitive assessment in aphasia.     

A case of crossed aphasia with echolalia after the resection of tumor in the right medial frontal lobe]

We report a right-handed woman, who developed a non-fluent aphasia after resection of astrocytoma (grade III) in the right medial frontal lobe. On admission to the rehabilitation department, neurological examination revealed mild left hemiparesis, hyperreflexia on the left side and grasp reflex on the left hand. Neuropsychologically she showed general inattention, non-fluent aphasia, acalculia, constructional disability, and mild buccofacial apraxia. No other apraxia, unilateral spatial neglect or extinction phenomena were observed. An MRI demonstrated resected areas in the right superior frontal gyrus, subcortical region in the right middle frontal gyrus, anterior part of the cingulate gyrus, a part of supplementary motor area. Surrounding area in the right frontal lobe showed diffuse signal change. She demonstrated non-fluent aprosodic speech with word finding difficulty. No phonemic paraphasia, or anarthria was observed. Auditory comprehension was fair with some difficulty in comprehending complex commands. Naming was good, but verbal fluency tests for a category or phonemic cuing was severely impaired. She could repeat words but not sentences. Reading comprehension was disturbed by semantic paralexia and writing words was poor for both Kana (syllabogram) and Kanji(logogram) characters. A significant feature of her speech was mitigated echolalia. In both free conversation and examination setting, she often repeated phrases spoken to her which she used to start her speech. In addition, she repeated words spoken to others which were totally irrelevant to her conversation. She was aware of her echoing, which always embarrassed her. She described her echolalic tendency as a great nuisance. However, once echoing being forbidden, she could not initiate her speech and made incorrect responses after long delay. Thus, her compulsive echolalia helped to start her speech. Only four patients with crossed aphasia demonstrated echolalia in the literature. They showed severe aphasia with markedly decreased speech and severe comprehension deficit. A patient with a similar lesion in the right medial frontal lobe had aspontaneity in general and language function per se could not be examined properly. Echolalia related to the medial frontal lesion in the language dominant hemisphere was described as a compulsive speech response, because some other 'echoing' phenomena or compulsive behavior were also observed in these patients. On the other hand, some patients with a large lesion in the right hemisphere tended to respond to stimuli directed to other patients, so called 'response-to-next-patient-stimulation'. This behavior was explained by disinhibited shift of attention or perseveration of the set. Both compulsive speech responses and 'response-to-next-patient-stimulation' like phenomena may have contributed to the echolalia phenomena of the present case.     

Right unilateral auditory agnosia following left lenticular hemorrhage

A 33-year old patient who had had left lenticular hemorrhage presented with an inability to understand with the right ear oral language and, in a less dramatic way, nonverbal sounds. This unilateral auditory agnosia was first associated with a right motor underutilization and right motor, sensitive, visual and auditive extinctions. Speech discrimination scores were 100% with the left ear and 15% with the right ear, even less in dichotic conditions. Tonal audiogram, as well as early and late components of the auditory evoked potentials were normal. Cerebral regional perfusion and metabolism were impaired over the left parietotemporal area. There was severe hypoactivation of the left hemisphere with right monaural verbal stimulations. Rehabilitation consisting of non-specific attention tasks and repetitions of words reaching only the right ear was undertaken 15 months after the stroke. The oral language comprehension improved, as did the left hemisphere activation, and the extinction phenomena disappeared, except for the auditory one. The unilaterality of the auditory agnosia could be due, in part, to a peculiar physiological processing in this patient, such as poor performance of his right ipsilateral auditory pathway which could be improved with practice. A striatal lesion could induce a spatial hemi-inattention as reflected by the multimodal extinction in this case. Besides, a lack of selective activation for verbal stimulation of the left hemisphere is suggested.     

Auditory sound agnosia without aphasia following a right temporal lobe lesion

A 55-year-old right-handed man showed inability to recognize the meaning of non-verbal sounds without impairment of language comprehension after a cerebrovascular accident. His auditory acuity was intact and no other sign of agnosia, apraxia or aphasia was detectable. His errors on a test of sound recognition were acoustic rather than semantic. Brain CT scan showed a small lesion in the posterior part of the right temporal lobe. This case suggests that auditory sound agnosia without language disorder can ensure a lesion confined to the right hemisphere, and that the deficit is discriminative rather than associative in nature.     

Audiovisual phonological mismatch produces early negativity in auditory cortex

During silent reading, visual information provided by letters is converted to auditory information in the mind. The purpose of this study was to identify the primary locus for auditory verbal imagery in the brain. Neuromagnetic recording was obtained from 10 right-handed study participants, who were instructed to identify infrequently occurring phonological mismatches between a random-ordered sequence of syllable sounds and a visually presented syllabogram sequence. The activity difference in early latency, calculated by subtracting the averaged responses to matched syllables from the averaged responses to mismatched syllables, showed a spatiotemporal profile strikingly similar to that of mismatch negativity. Auditory imagery of forthcoming verbal sounds may establish a memory trace as a template for imagery-based mismatch negativity generation in the auditory cortex.     

Material specific hemispherical arousal.

It has been previously demonstrated that warning stimuli (WS) reduce reaction time (RT) by causing cortical activation. The purpose of this study was to use verbal and non-verbal WS to see if these stimuli asymmetrically activate the cerebral hemispheres.Sixteen right-handed Ss were given a manual RT task using a light as the RT stimulus and either verbal or non-verbal sounds as WS. RTs by the right hand were significantly faster with verbal WS than with non-verbal WS. There were no significant differences for the left hand between the verbal and non-verbal WS. These results give partial support to the asymmetrical activation hypothesis.     

非抽搐性癫痫持续状态五例及文献复习

目的 探讨非抽搐性癫痫持续状态(NCSE)患者的临床表现及持续脑电监测的脑电图(EEG)特征.方法 对自2008年11月至2009年12月北京大学人民医院急诊科收治的5例NCSE患者行持续EEG监测检查,观察其EEG特征及临床表现.结果 5例均出现发作性意识障碍,其中4例出现烦躁、易怒或躁狂,3例表现出精神运动迟滞和遗忘,2例出现言语自动症和失认,1例出现定向障碍.所有患者的EEG均出现广泛性但一侧明显的异常放电.静脉注射地两泮后,3例患者临床症状迅速改善.结论 NCSE并非罕见,持续EEG监测能查出本病,早期诊断,及时治疗可改善患者预后,临床应注意与其他引起意识紊乱的疾病相鉴别.     

Nonverbal auditory agnosia with lesion to Wernicke's area

We report the case of patient M, who suffered unilateral left posterior temporal and parietal damage, brain regions typically associated with language processing. Language function largely recovered since the infarct, with no measurable speech comprehension impairments. However, the patient exhibited a severe impairment in nonverbal auditory comprehension. We carried out extensive audiological and behavioral testing in order to characterize M's unusual neuropsychological profile. We also examined the patient's and controls’ neural responses to verbal and nonverbal auditory stimuli using functional magnetic resonance imaging (fMRI). We verified that the patient exhibited persistent and severe auditory agnosia for nonverbal sounds in the absence of verbal comprehension deficits or peripheral hearing problems. Acoustical analyses suggested that his residual processing of a minority of environmental sounds might rely on his speech processing abilities. In the patient's brain, contralateral (right) temporal cortex as well as perilesional (left) anterior temporal cortex were strongly responsive to verbal, but not to nonverbal sounds, a pattern that stands in marked contrast to the controls’ data. This substantial reorganization of auditory processing likely supported the recovery of M's speech processing.     

Presenile dementia diagnosed as posterior cortical atrophy

Posterior cortical atrophy (PCA) was originally proposed in 1988 based on five cases of dementia presenting characteristic clinical symptoms. The concept of PCA is still not generally accepted. Herein, we present a case of a presenile female with PCA. A 57‐year‐old woman was brought to the hospital by her older sister. The patient's chief complaints were that she could not drive a car safely and had caused numerous traffic accidents. Construction apraxia and unilateral spatial agnosia were detected by neuropsychological tests. The patient could not write a coherent the letter even though she was well educated. In addition, she demonstrated slight memory disturbance and she needed her sister's support in daily life. Magnetic resonance imaging and single photon emission computed tomography examinations confirmed bilateral posterior atrophy and significant hypoperfusion in the occipital regions. The neuropathological background of PCA remains unclear. Therefore, the concept of PCA should be validated by the accumulation of information from more cases.     

Brain Single Photon Emission Computed Tomography Imaging in Landau-Kleffner Syndrome

Summary: Five right–handed children with Landau-Kleffner syndrome (LKS) who had disease onset between the ages of 3 and 9 years were studied with EEG and single-photon emission computed tomography (SPECT) before and, in four cases, after 6 months of corticosteroid treatment. EEG findings included both focal and generalized spikes as well as spike-wave discharges with bilateral temporal predominance. These increased markedly during sleep in 1 child, and continuous spike-and-wave complexes appeared during slow-wave sleep in another patient. Neuropsychological testing demonstrated verbal auditory agnosia. Magnetic resonance imaging (MRI) was performed in 4 children and was normal. Brain SPECT imaging demonstrated abnormal perfusion in the left temporal lobe in all patients. The response to corticosteroid therapy was mixed. Our findings reinforce the concept that LKS is a functional disease affecting the language-dominant brain areas. We conclude that SPECT imaging may be of diagnostic assistance in the evaluation of this syndrome of unknown etiology.     

Non-credible language deficits following mild traumatic brain injury

Identification of non-credible memory and other cognitive symptoms has received widespread attention within the past two decades. However, minimal information is available regarding patterns of non-credible language symptoms. We present the case of a 36-year-old female civil litigant who displayed delayed onset, severe, relatively focal speech and language symptoms, including difficulties with articulation, dysfluent speech, expressive language impairments with minor receptive difficulties, and lack of prosody, subsequent to a minor head trauma. On neuropsychological evaluation 3 years post injury, the patient presented with the same speech/language characteristics, but additionally exhibited a vague “foreign accent.” Cognitive scores generally were normal with the exception of poor performance on many language tasks and processing/motor speed. The patient showed passing performance on most measures of response bias, but she failed effort indicators requiring rapid letter discrimination (b Test), rapid verbal repetition (timed forward digit span), and sensory function (finger agnosia errors) while passing effort indicators falling within the domains of memory, math/number skills, visuo-constructional ability, and attention. Thus, the type of failed effort indicators predicted the categories of standard cognitive tests on which she underperformed. Personality testing revealed patterns generally consistent with hysterical personality orientation. Given her long-standing history of multiple unexplained medical symptoms, the patient was diagnosed with a somatization disorder, as well as a current conversion disorder involving language symptoms. However, given her compensation-seeking status, the possibility of additional conscious feigning of symptoms could not be ruled out. The need for validation of additional measures to detect feigned language impairment is recommended.      

Simultanagnosia through the eyes of an artist

An 87-year-old artist experienced a top-of-the-basilar-artery embolic stroke secondary to atrial fibrillation and manifested a visual agnosia. Prior to her stroke, she painted scenes solely from memory. During her stroke recovery, her serial drawings and paintings revealed selective attention to the left lower quadrant, with important aspects of the whole image "clipped," as if missing from her internal representation of the whole object. Years later, her artistic abilities returned with only minor differences from those prior to her stroke.