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.     

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.     

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.     

Auditory affective agnosia. Disturbed comprehension of affective speech.

Hughlings Jackson noted that, although some aphasic patients were unable to use propositional speech, affective speech appeared to be spared. The purpose of this experiment was to study patients with unilateral hemispheric disease in order to ascertain if there are hemispheric asymmetries in the comprehension of affective speech. Six subjects had right temporoparietal lesions (left unilateral neglect) and six subjects had left temporoparietal lesions (fluent aphasias). These subjects were presented with 32 tape recorded sentences. In 16 trials the patients were asked to judge the emotional mood of the speaker (happy, sad, angry, indifferent) and in 16 trials the patients were asked to judge the content. Line drawings containing facial expressions of the four emotions or line drawings corresponding with the four basic contents were displayed with each sentence and the patient responded by pointing. All 12 subjects made perfect scores on the content portion of the test. On the emotional portion the right hemispheric patients scored a mean of 4-17 and the left hemispheric group scored a mean 10-17. The difference between these means is significantly (P less than 0-01) and suggests that patients with right hemispheric dysfunction and neglect have a defect in the comprehension of affective speech.     

Apperceptive form visual agnosia caused by anti-TNFalpha therapy to rheumatoid arthritis]

TNFalpha plays an important role as an inflammatory mediator in both several autoimmune diseases and multiple sclerosis. Anti-TNFalpha antibody has been widely used to treat rheumatoid arthritis and Crohn's disease. On the. other hand, anti-TNFalpha antibody treatment increased recurrence rate in clinical trials for multiple sclerosis. We report a patient with rheumatoid arthritis without past history of any neurological disorders, who developed diplopia, ataxia, and visual agnosia specific to line drawing in the course of anti-TNFalpha antibody treatment. MRI studies detected multiple demyelinating lesions in the cerebral white matter and brainstem. The present case indicates that careful observation of neurological symptoms is important in the course of anti-TNFalpha antibody treatment, even in patients without past history of demyelinating diseases.     

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 agnosia and auditory spatial deficits following left hemispheric lesions: evidence for distinct processing pathways

Auditory recognition and auditory spatial functions were studied in four patients with circumscribed left hemispheric lesions. Patient FD was severely deficient in recognition of environmental sounds but normal in auditory localisation and auditory motion perception. The lesion included the left superior, middle and inferior temporal gyri and lateral auditory areas (as identified in previous anatomical studies), but spared Heschl's gyrus, the acoustic radiation and the thalamus. Patient SD had the same profile as FD, with deficient recognition of environmental sounds but normal auditory localisation and motion perception. The lesion comprised the postero-inferior part of the frontal convexity and the anterior third of the temporal lobe; data from non-human primates indicate that the latter are interconnected with lateral auditory areas. Patient MA was deficient in recognition of environmental sounds, auditory localisation and auditory motion perception, confirming that auditory spatial functions can be disturbed by left unilateral damage; the lesion involved the supratemporal region as well as the temporal, postero-inferior frontal and antero-inferior parietal convexities. Patient CZ was severely deficient in auditory motion perception and partially deficient in auditory localisation, but normal in recognition of environmental sounds; the lesion involved large parts of the parieto-frontal convexity and the supratemporal region. We propose that auditory information is processed in the human auditory cortex along two distinct pathways, one lateral devoted to auditory recognition and one medial and posterior devoted to auditory spatial functions.     

Retinal projection to a rotated tectal reimplant following long-term tectal denervation in adult goldfish

Following optic nerve crush, the precise termination sites of regenerating goldfish optic axons may be influenced by the presence or abscence of degenerating axonal debris from the previous projection. We investigated whether tectal polarity reversal can be induced in the absence of axonal debris The right optic tectum was denervated by contralateral eye removal. One year later, when no debris was present, a piece of the right tectum was rotated and innervation by the right eye was induced by removal of the left tectum. The new ipsilateral projection to the rotated region was correspondingly rotated. It is concluded that retention of tectal polarity is not dependent upon degenerating axonal debris.     

Associative visual agnosia: a case study

This report describes a case of associative visual agnosia caused by a left sided, cortico-subcortical, inferior temporo-occipital infarction. Performance on visual perceptual tests was normal, while it was defective on visual classification tasks. Visual agnosia was interpreted as a visuo-verbal disconnection plus a categorization deficit for visual meaningful common stimuli. The left occipito-temporal lesion disrupted the visual classification process and prevented access of visual information to language areas and limbic system. The absence of right hemispheric lesion accounted for the normal recognition of familiar faces and other unique individual stimuli such as familiar places, whose recognition occurs through contextual evocation.     

Drawings by patients with unilateral visuospatial agnosia]

Drawings made by 25 patients with neurosurgical diseases causing focal lesions in the posterior areas of the right, not dominant cerebral hemisphere due to expanding changes. Experimental clinical investigations by the method of Luria demonstrated in these cases presence of left-sided visuospatial agnosia. The material was analysed from the point of view of the features of drawings characteristic for the syndrome of disturbances and the localizatory and diagnostic value of drawings. Characteristic disturbances of drawings and their placement were observed suggesting that the patients ignored the left half of the visual space due to damage to the right parieto-occipital non-dominant cerebral hemisphere. The drawing test is regarded as a valuable method for the diagnosis and localization of lesions in the neurological and neuropsychological practice.     

Primary medulla oblongata germinoma in a male patient

Germinoma mainly occurs in the pituitary stalk, pineal region, and basal ganglia. Sex predominance of the tumor in males in the pineal region and basal ganglia is well known. Primary germinoma of the medulla oblongata is rare, with only eight reports, mostly in females. We report the second male patient with primary medulla oblongata germinoma, without chromosomal abnormality, who was successfully treated with surgery, chemotherapy, and radiotherapy.     

Implicit integration in a case of integrative visual agnosia

We present a case (SE) with integrative visual agnosia following ischemic stroke affecting the right dorsal and the left ventral pathways of the visual system. Despite his inability to identify global hierarchical letters [Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive Psychology, 9, 353-383], and his dense object agnosia, SE showed normal global-to-local interference when responding to local letters in Navon hierarchical stimuli and significant picture-word identity priming in a semantic decision task for words. Since priming was absent if these features were scrambled, it stands to reason that these effects were not due to priming by distinctive features. The contrast between priming effects induced by coherent and scrambled stimuli is consistent with implicit but not explicit integration of features into a unified whole. We went on to show that possible/impossible object decisions were facilitated by words in a word-picture priming task, suggesting that prompts could activate perceptually integrated images in a backward fashion. We conclude that the absence of SE's ability to identify visual objects except through tedious serial construction reflects a deficit in accessing an integrated visual representation through bottom-up visual processing alone. However, top-down generated images can help activate these visual representations through semantic links.     

Visual agnosia and amnesia from a left unilateral lesion

This case report describes the behavior of a patient with a visual agnosia of the associative type, developing to optic agnosia at a later stage. Language, general intelligence and right hemisphere functions were well preserved, but recognition of visually presented objects, colors, faces, words, and complex stimuli was impaired. Agnosia was accompanied by a multimodal amnestic syndrome. CT displayed a focal left hemisphere lesion. The observed pathomorphology is not consistent with a bilateral visuolimbic disconnection syndrome, as suggested from previous case studies. Significant components of visual semantic processing may be executed by the left hemisphere.     

Visual agnosia in a child with non-lesional occipito-temporal CSWS

In this paper we describe a case of severe visual agnosia in a child with an electrophysiological pattern of continuous spike-wave discharges in slow sleep (CSWS) in the occipito-temporal regions. The neuropsychological spectrum related to this phenomenon is discussed. Published paediatric reports associate visual agnosia (i.e. an inability to recognize objects without impairment of visual acuity) mainly with symptomatic occipito-temporal aetiology (e.g. cortical dysplasia, vascular insults) and other neurological symptoms (e.g. autism). We describe a detailed 2 year electrophysiological and neuropsychological follow-up of an 8-year-old boy with sporadic seizures, occipito-temporal CSWS and visual agnosia. The growth and neurological development of the child had been considered as normal, neurological examination did not reveal any focal signs, visual acuity was intact and MRI was normal. First EEG and six consecutive 24 h video EEG recordings during the follow-up of 22 months showed continuous spike-and-wave activity covering over 85% of the non-REM sleep. According to structured neuropsychological tests (Wechsler Intelligence Scale for Children--Third Edition, A Developmental Neuropsychological Assessment (NEPSY), Test of Visual-Perceptual Skills, Corsi block, Hooper Visual Organization Test) the boy had normal verbal intelligence but major deficits in visual perception, especially in object recognition, impaired shape discrimination and detection, and poor copying skills. Attention and executive functions were intact. There were no difficulties in short- or long-term memory. Verbal cues and naming the objects improved visual memory. Tracing the objects with a finger or by moving the head improved object recognition. Currently the boy attends a special school with a rehabilitation plan including neuropsychological and occupational therapies. This case adds a new facet to the spectrum of neuropsychological deficits in children with CSWS. Sleep EEG should be included in the etiological studies of children with specific neuropsychological problems and detailed neuropsychological assessment is needed for diagnostic and rehabilitation purposes.     

Double localization of a cerebral germinoma. Case report

A germinoma located in both the pineal and suprasellar regions remains rare. The clinical expression can be polymorphic, although brain imaging reveals specific signs. We report the case of a 16-year-old boy who presented with diabetes insipidus of six months' standing, associated with visual loss and Parinaud's syndrome. Brain MRI showed a tumor in both the pineal and suprasellar regions. A stereotaxic biopsy targeting the infundibular growth confirmed the diagnosis of ectopic germinoma, which was successfully treated by radiotherapy and chemotherapy. The incidence of bifocal germinoma, its clinical and radiological characteristics as well as the therapeutic strategies to adopt are discussed.