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.     

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.     

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.     

Pure word deafness: a case report of an atypical manifestation of Alzheimer’s disease

Neurological Sciences - Auditory agnosia refers to the impairments in sound recognition despite intact hearing and written language abilities. When auditory agnosia is specific to spoken language,...     

Language disorders in Landau-Kleffner syndrome

In the present long-term study, we analyzed language disorders in four patients with Landau-Kleffner syndrome. Their common first symptoms were disability in understanding spoken words, followed by inarticulation and a decreased amount of speech. All patients showed auditory verbal agnosia to some degree at some stage of their illness. However, one patient showed typical sensory aphasia as the first symptom, and another patient showed nonverbal auditory agnosia followed by pure word deafness. Thus, patients with Landau-Kleffner syndrome show sequential and sometimes hierarchical language disorders beginning with sensory aphasia, followed by auditory agnosia, and finally word deafness during their disease process. During long-term follow-up (20 to 30 years), all patients showed marked recovery in language without any intellectual handicap, but with some disability in spoken language, auditory verbal perception, and a discrepancy between Wechsler Verbal and Performance IQ scores.     

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.     

In Process Citation

Pure word deafness (auditory verbal agnosia) is characterized by an impairment of auditory comprehension, repetition of verbal material and writing to dictation whereas spontaneous speech production and reading largely remain unaffected. Sometimes, this syndrome is preceded by complete deafness (cortical deafness) of varying duration. Perception of vowels and suprasegmental features of verbal utterances (e.g., intonation contours) seems to be less disrupted than the processing of consonants and, therefore, might mediate residual auditory functions. Often, lip reading and/or slowing of speaking rate allow within some limits to compensate for speech comprehension deficits. Apart from a few exceptions, the available reports of pure word deafness documented a bilateral temporal lesion. In these instances, as a rule, identification of nonverbal (environmental) sounds, perception of music, temporal resolution of sequential auditory cues and/or spatial localization of acoustic events were compromised as well. The observed variable constellation of auditory signs and symptoms in central hearing disorders following bilateral temporal disorders, most probably, reflects the multitude of functional maps at the level of the auditory cortices subserving, as documented in a variety of non-human species, the encoding of specific stimulus parameters each. Thus, verbal/nonverbal auditory agnosia may be considered a paradigm of distorted "auditory scene analysis" (Bregman 1990) affecting both primitive and schema-based perceptual processes. It cannot be excluded, however, that disconnection of the Wernicke-area from auditory input (Geschwind 1965) and/or an impairment of suggested "phonetic module" (Liberman 1996) contribute to the observed deficits as well. Conceivably, these latter mechanisms underly the rare cases of pure word deafness following a lesion restricted to the dominant hemisphere. Only few instances of a rather isolated disruption of the discrimination/identification of nonverbal sound sources, in the presence of uncompromised speech comprehension, have been reported so far (nonverbal auditory agnosia). As a rule, unilateral right-sided damage has been found to be the relevant lesion.     

Long-term follow-up of auditory agnosia as a sequel of herpes encephalitis in a child

We report a pediatric patient with auditory agnosia as a sequel of herpes encephalitis. His early development was completely normal. He uttered three words at 12 months old. Disease onset was 1 year and 2 months of age. He was discharged from the hospital seemingly with no sequel; however, he could not recover his intelligible words even at age 2 years. He was diagnosed as having auditory agnosia caused by bilateral temporal lobe injury. We began to train him at once, individually and intensively. Adult patients with pure auditory agnosia followed by two episodes of temporal lobe infarction have impairment in central hearing but not inner language. Therefore, they can communicate by reading and writing. Moreover, impairment in hearing is not always severe and is often transient. However, despite long-term (more than 15 years) energetic education and almost normal intellectual ability (Performance IQ of Wechsler Intelligence Scale for Children-Revised was 91), our patient's language ability was extremely poor. Cerebral plasticity could not work fully on our patient, whose bilateral temporal lobe was severely injured in early childhood. The establishment of a systematic training method in such patients is an urgent objective in this field.     

Visual hypoemotionality and prosopagnosia associated with right temporal lobe isolation

Emotional hyporeactivity to visual stimuli (so-called visual hypoemotionality) was observed in a 71-yr-old woman following a cerebral infarction in the territory of the posterior cerebral arteries. Other visual disturbances included severe prosopagnosia, dense left hemianopia and mild left hemineglect. There was neither object agnosia nor any involvement of language, memory or intellectual functions. Hypoemotionality was found only for visual stimuli, since auditory and tactile modalities were totally spared, suggesting a visual-limbic disconnection mechanism. From CT data, and referring to previous evidence suggesting a right-hemisphere prevalence for emotional functions, it is postulated that the right occipital lesion, leading to a total right temporal lobe isolation, was mainly responsible for the patient's emotional disturbances.     

Common dimensions of visual and auditory agnosia and an explanation of the auditory recognition deficit in aphasia.

An experimental analysis of auditory recognition disturbances was performed; 81 patients with localized cerebral lesions were examined with a recognition test for meaningful sounds and with a nonverbal intelligence test (Block Design). Sensory stimulation was 5 or 15 sec for each sound. Nonverbal intelligence accounted for a considerable and significant amount of variance in recognition performance. The aphasic group was more impaired in auditory recognition than were both the other groups, i.e., patients with right or left hemispheric lesions without aphasia. The auditory recognition disturbance in the aphasic group depended to a significant extent on stimulus duration, which means a slowing down of the recognition process in aphasia. The analogies to studies on visual agnosia are striking. In both modalities, recognition depends on intellectual functioning, sensory disturbances or reduced sensory input, and the presence of aphasia.     

Neurolinguistic analysis of the language abilities of a patient with a "double disconnection syndrome": a case of subangular alexia in the presence of mixed transcortical aphasia.

In contrast to the classic form of alexia without agraphia, subangular alexia results from a single lesion located deep in the white matter of the left parietal lobe. In the present report, a patient with subangular alexia and features of mixed transcortical aphasia is described. Neurolinguistic findings include: alexia without agraphia, paucity of spontaneous speech, moderate auditory comprehension difficulty, excellent repetition, echopraxia, colour agnosia, and naming disorder. Neurolinguistic tests revealed intact phonological organisation and grammatical filter." Our studies revealed a "double disconnection syndrome," the co-existence of two relatively rare neurobehavioural disorders. Furthermore, the studies reported here clearly show dissociations of language functions in both the visual and auditory modality, which demonstrates that the stages of language processing are separable.     

Impaired recognition of meaningful sounds in Alzheimer's disease

We studied recognition of meaningful nonverbal sounds using a sound-picture matching test in 18 patients with senile dementia of the Alzheimer type (SDAT) and 19 age-matched controls. A significant impairment of sound recognition was found in the SDAT group, consistent with auditory sound agnosia. Although sound recognition performance correlated significantly with auditory verbal comprehension scores, a sound recognition defect was also identifiable in the subgroup of patients with SDAT who had normal verbal comprehension. Qualitative analysis of sound recognition errors revealed that nonaphasic patients with SDAT made predominantly acoustic errors, whereas semantic errors were found almost exclusively in aphasic patients. These findings suggest that the auditory sound agnosia of patients with SDAT may be subdivided into perceptual-discriminative and semantic-associative types.     

A case of slowly progressive aphasia accompanied with auditory agnosia]

A 68-year-old right-handed woman was admitted to our hospital because of difficulty to speak and understand conversation over 10 years. She was able to make herself by writing. No change in her personality or behavioral abnormality was observed so that she could live without help. Although her WAIS score and auditory brain stem response were normal, she could not understand the speech or distinguish the sound. She also spoke plenty of words fluently, resulting in undifferentiated jargon. She did not make any effort in speaking. Her speech was, however, unclear and hard to understand. Brain MRI scan disclosed a moderate atrophy of bilateral temporal lobe and enlargement of Sylvius fissure. A three-dimension reconstructed brain surface image showed enlargement of the perisylvian fissure, and atrophy of the gyrus frontalis inferior, operculum, gyrus temporal superior, bilaterally. Reduced cerebral blood flow was demonstrated on 99mTc-ECD SPECT in the left thalamus and bilateral fronto-temporal lobe. A diagnosis of slowly progressive aphasia with auditory agnosia was made. Our case suggests that bilateral disturbance of neuronal network between the primary auditory area and the secondary auditory area is responsible to the consequence of auditory agnosia.     

The influence of premorbid language skills and behavior on language recovery in children with verbal auditory agnosia

Previous studies of children with Landau-Kleffner syndrome and related language-epilepsy syndromes have focused on the relationship of seizure control to language recovery. We examined the effect of premorbid language skills and behavior, as well as some characteristics of clinical seizures and electroencephalograms, on language recovery in a retrospective study of 67 children with the severe receptive and expressive language disorder, verbal auditory agnosia. Fifty-eight percent of these children had seizures, 76% were autistic, and 24% had a history of language regression after showing previously normal language skills. The duration of language loss was not influenced by the persistence of clinical seizures. Premorbid language and behavior were more predictive of language recovery in these children. Most children with normal early language (acquired verbal auditory agnosia) had onset of language loss after age 3 years, in contrast to those with abnormal early language. Children with acquired verbal auditory agnosia were more likely to show fluctuations in language skills than those in other groups. Autistic children were more likely to begin having seizures before age 3 years, and had a longer duration of language loss and lower educational placement at time of last follow-up than those with normal behavior. This study emphasizes the importance of assessing premorbid language and behavior in predicting recovery of language skills in children with language-epilepsy syndromes.     

Visual and tactile agnosia

A patient presented with visual and tactile agnosia due to a spontaneous left occipito-temporal hematoma. Major memory and spatial orientation disorders were also noted, but language, gestures, auditory and olfactory perception, and interior visual imagerie were unaffected. A review of the literature since 1970 found 6 cases of an association of this type among 17 patients with visual agnosia. There appears to be no relationship between the presence of tactile agnosia and the global or partial character of the visual agnosia, the severity of memory disturbances, the presence of visuoverbal disconnection or visual imagery disorders. In contrast, these cases differed in that the lesions were more extensive and extended beyond the internal occipital regions: they were widespread in 3 cases and in the left internal occipital and parietal region in 1 case. In the patient reported in this paper there was a wide lesion of the posterior white matter of the left hemisphere.     

A child with refractory complex partial seizures, right temporal ganglioglioma, contralateral continuous electrical status epilepticus, and a secondary Landau-Kleffner autistic syndrome

A 7-year-old, right-handed girl started to have seizures at age 1 year 4 months. She developed normally until age 4 when she had worsening of seizures with auditory verbal agnosia, complete aphasia, and a behavioral disorder fulfilling the diagnostic criteria of autism. Medical therapy failed. MRI revealed a right temporal tumor. Video/EEG monitoring at age 7 showed contralateral electrical status epilepticus in wakefulness and sleep and ipsilateral onset of seizures. Resection (ganglioglioma with excessive inflammation) resulted in seizure freedom and marked reduction of the autistic features. This case is unique for being, to our knowledge, (1) the first in which a lesion located in the right, rather than left, temporal lobe resulted in secondary falsely localizing left temporal lobe electrical status epilepticus with a clinical picture of Landau-Kleffner syndrome and autism, and (2) the fourth reported patient with lesional Landau-Kleffner syndrome to respond to resective surgery.     

Sound lateralisation in patients with left or right cerebral hemispheric lesions: relation with unilateral visuospatial neglect

OBJECTIVES: To localise the brain lesion that causes disturbances of sound lateralisation and to examine the correlation between such deficit and unilateral visuospatial neglect. METHOD: There were 29 patients with right brain damage, 15 patients with left brain damage, and 22 healthy controls, who had normal auditory and binaural thresholds. A device was used that delivered sound to the left and right ears with an interaural time difference using headphones. The amplitude (an index of ability to detect sound image shifts from the centre) and midpoint (an index of deviation of the interaural time difference range perceived as the centre) parameters of interaural time difference were analysed in each subject using 10 consecutive stable saw toothed waves. RESULTS: The amplitude of interaural time difference was significantly higher in patients with right brain damage than in controls. The midpoint of the interaural time difference was significantly more deviated in patients with right brain damage than in those with left brain damage and controls (p<0. 05). Patients with right brain damage with lesions affecting both the parietal lobe and auditory pathway showed a significantly higher amplitude and deviated midpoint than the controls, whereas right brain damage with involvement of only the parietal lobe showed a midpoint significantly deviated from the controls (p<0.05). Abnormal sound lateralisation correlated with unilateral visuospatial neglect (p<0.05). CONCLUSIONS: The right parietal lobe plays an important part in sound lateralisation. Sound lateralisation is also influenced by lesions of the right auditory pathway, although the effect of such lesions is less than that of the right parietal lobe. Disturbances of sound lateralisation correlate with unilateral visuospatial neglect.     

Auditory perception in auditory neuropathy: clinical similarity with auditory verbal agnosia

The precise features of auditory perception in patients with auditory neuropathy have not been well described. In the present study, we examined auditory perception in a patient with auditory neuropathy. The patient was a right-handed 7-year-old boy. His chief complaint was delayed speech and suspected of verbal learning disability. He could talk, read and repeat rather fluently but could not understand fully what was asked. V-IQ, P-IQ and F-IQ of Wechsler Scale for Children III-R were 53, 118 and 81, respectively. Pure tone audiogram was completely normal. His speech discrimination ability was very poor. He could identify environmental sounds with visual matching. He could differentiate intensity difference but not time difference. This phenomenon was reported in patients with hemispheric symptoms. These clinical features are very similar to verbal auditory agnosia. ABR showed no response at 90dBnHL alternating clicks and tone bursts. Click evoked and distortion product otoacoustic emissions (OAE) were normal. Electrocochleogram was also normal. Motor and sensory nerve conduction velocity was completely normal. Pa of MLR and N1 of SVR were present. His diagnosis should be "pure type" of auditory neuropathy or auditory nerve disease. Importance of both ABR and OAE examination should be widely announced and auditory neuropathy must be campaigned stressed to be clinical entity among personnel who take care of children with speech delay.     

Auditory neglect.

Auditory neglect was investigated in normal controls and in patients with a recent unilateral hemispheric lesion, by requiring them to detect the interruptions that occurred in one ear in a sound delivered through earphones either mono-aurally or binaurally. Control patients accurately detected interruptions. One left brain damaged (LBD) patient missed only once in the ipsilateral ear while seven of the 30 right brain damaged (RBD) patients missed more than one signal in the monoaural test and nine patients did the same in the binaural test. Omissions were always more marked in the left ear and in the binaural test with a significant ear by test interaction. The lesion of these patients was in the parietal lobe (five patients) and the thalamus (four patients). The relation of auditory neglect to auditory extinction was investigated and found to be equivocal, in that there were seven RBD patients who showed extinction, but not neglect and, more importantly, two patients who exhibited the opposite pattern, thus challenging the view that extinction is a minor form of neglect. Also visual and auditory neglect were not consistently correlated, the former being present in nine RBD patients without auditory neglect and the latter in two RBD patients without visual neglect. The finding that in some RBD patients with auditory neglect omissions also occurred, though with less frequency, in the right ear, points to a right hemisphere participation in the deployment of attention not only to the contralateral, but also to the ipsilateral space.     

A case of visual agnosia for picture with right occipital lobe infarction]

We report a 74-year-old right-handed man with visual agnosia for picture due to right occipital lobe infarction. The patient had a remarkable impairment in visual recognition for standardized pictures made by Snodgrass and Vanderwart, in addition to left hemianopsia, left visuospatial neglect, and mild prosopagnosia. The visual agnosia for picture was generally recognized as a mild-type of the visual object agnosia, which was extremely rare in the patients with right occipital lesion. We discussed the mechanism of the visual agnosia in the right occipital lesion. Therefore, it raises the possibility that the broad impairment of the right occipital artery territory including parahippocampal gyrus as well as corpus callosum can cause the visual agnosia for picture.