11/1255. Hearing without hair cells? A case report. Audiograms from a five year old accident victim with a profound hearing loss are compared to temporal bone and brain stem histological findings. One temporal bone was evaluated using surface preparation and transmission electron microscope techniques. The other temporal bone was evaluated using serial section procedures. No sensory cells were present in either cochlea. This unusual finding is discussed. Evaluation of ventral cochlear nuclei showed a 50 per cent loss of neurons on both sides. ( info) |
12/1255. The assessment and treatment of deaf children with psychiatric disorders. The assessment and treatment of deaf children with psychiatric disorder is intimately related to the individual child's communication, which in turn is affected by a number of factors, medical, social, and cultural. The deafness can be aetiologically related to the psychiatric disorder or can be incidental. Treatment strategies should be adapted to meet the individual child and family's needs. Deaf professionals have a vital role in mental health services for this population. The use of an interpreter can clarify communication and cultural issues for deaf and hearing children, families, and professionals. ( info) |
13/1255. Labyrinthine involvement in Langerhans' cell histiocytosis. BACKGROUND: Langerhans' cell histiocytosis, a rare condition caused by the proliferation of abnormal Langerhans' cells ('LCH cells') and an accompanying granulomatous infiltrate, can affect several organs including the ear. External and middle ear involvement are common with a reported incidence as high as 61%. The bony labyrinth is resistant to erosion by the granulation tissue, thereby protecting the cochlea and vestibular structures. Probably for this reason, involvement of the inner ear is rare, with few case reports in the literature. patients: We report two girls, one with bilateral and the other with unilateral mastoid involvement, in whom there was invasion of the labyrinth. The first girl had 'single system' LCH affecting only bone and developed an acute hearing loss due to invasion of the cochlea, while the second had both bone and skin involvement and labyrinthine involvement was diagnosed on imaging prior to the onset of labyrinthine symptoms. CONCLUSION: Inner ear involvement can lead to permanent deafness, which may be prevented by early institution of treatment. Threatened inner ear involvement requires urgent systemic medical therapy with steroids, possibly combined with chemotherapy. ( info) |
14/1255. Discourse deficits following right hemisphere damage in deaf signers. Previous findings have demonstrated that hemispheric organization in deaf users of American sign language (ASL) parallels that of the hearing population, with the left hemisphere showing dominance for grammatical linguistic functions and the right hemisphere showing specialization for non-linguistic spatial functions. The present study addresses two further questions: first, do extra-grammatical discourse functions in deaf signers show the same right-hemisphere dominance observed for discourse functions in hearing subjects; and second, do discourse functions in ASL that employ spatial relations depend upon more general intact spatial cognitive abilities? We report findings from two right-hemisphere damaged deaf signers, both of whom show disruption of discourse functions in absence of any disruption of grammatical functions. The exact nature of the disruption differs for the two subjects, however. Subject AR shows difficulty in maintaining topical coherence, while SJ shows difficulty in employing spatial discourse devices. Further, the two subjects are equally impaired on non-linguistic spatial tasks, indicating that spared spatial discourse functions can occur even when more general spatial cognition is disrupted. We conclude that, as in the hearing population, discourse functions involve the right hemisphere; that distinct discourse functions can be dissociated from one another in ASL; and that brain organization for linguistic spatial devices is driven by its functional role in language processing, rather than by its surface, spatial characteristics. ( info) |
15/1255. The Scheibe cochlea deformity with macrocephaly: a case for single channel implantation. An 11-year-old congenitally deaf child with bilateral primitive common cavity (Scheibe type) cochleosaccular dysplasia and benign familial macrocephaly was implanted with an extracochlear single channel device with an ear level speech processor. This paper describes the assessment, findings, dilemmas in decision making, surgical procedure and the favourable outcome after implanting. The relevant literature has been reviewed and our case is presented for the unusual combination of features. ( info) |
| A fourth kindred displaying the triad of hereditary nephritis, deafness and thrombocytopenia with giant platelets is described. Renal involvement, a common cause of death amongst afflicted subjects, appears to have a better prognosis in the affected members of this family. Although the electron microscopic appearance of the megakaryocytes in the present case appears similar to that in previously reported cases, we suggest that the "giant" platelets may result from a degenerative process of megakaryocytes leading to nuclear regression and cytoplasmic fragmentation, rather than the usual blebbing process. ( info) |
17/1255. Hereditary sensory neuropathy with deafness and dementia: a clinical and neuroimaging study. We describe three sibling patients with autosomal dominantly inherited sensory neuropathy, sensorineural hearing loss and dementia. The features of cognitive-behavioral deficits in the patients, including executive dysfunction, apathy, indifference and inattention, were consistent with a frontal lobe dysfunction. magnetic resonance imaging showed a diffuse brain atrophy. A fluorodeoxyglucose positron emission tomography in one patient and a single photon emission computed tomography in another demonstrated a glucose hypometabolism or a hypoperfusion in the medial frontal and thalamic regions. Primary frontal involvement or frontal dysfunction secondary to thalamic lesions may contribute to the nature of dementia in these patients. ( info) |
18/1255. Implantation of patients with prelingual long-term deafness. The purpose of this paper is to provide performance data on long-term congenitally and prelingually deafened children and adults who are implanted with the CLARION Multi-Strategy Cochlear Implant and who use the Continuous Interleaved Sampler (CIS) speech processing strategy. Open-set speech perception was assessed preoperatively and postoperatively with word and sentence recognition tests. Results indicate that a majority of subjects showed improvement from preoperative performance to the last available postoperative evaluation. These results represent a change from previously reported data on a similar population who used earlier speech processing strategies. ( info) |
19/1255. Fractionation of visual memory: evidence from a case with multiple neurodevelopmental impairments. It is known that the adult visual memory system is fractionable into functionally independent cognitive subsystems, selectively susceptible to brain damage. However, it is unclear whether these cognitive subsystems can fractionate developmentally. The present study describes an investigation of visual memory of a patient (PE) with multiple developmental disorders. PE was congenitally deaf, had Gilles de la tourette syndrome and autism, with non-verbal ability in the normal range. The patient presented with a recognition memory impairment for unknown human faces. This contrasted with his superior recognition memory for unknown buildings, landscapes and outdoor scenes. PE's memory impairment for faces could not be explained by a general deficit in face processing. Interestingly, PE also showed a recognition memory impairment for animals. These findings indicate that different domains of the visual memory system can be fractionated developmentally. In particular, it demonstrates that topographical memory can develop independently from other aspects of visual memory. ( info) |
20/1255. Uniparental isodisomy resulting from 46,XX,i(1p),i(1q) in a woman with short stature, ptosis, micro/retrognathia, myopathy, deafness, and sterility. We report on a 43-year-old woman who was referred for evaluation because of minor facial anomalies, myopathy, sterility, short stature, hearing loss, downward slant of palpebral fissures, bilateral ptosis, severe micro/retrognathia, high arched palate, and scoliosis. Cytogenetic analyses utilizing GTG/CBG bandings showed presence of one i(1p) and one i(1q) without normal chromosome 1 homologues. fluorescence in situ hybridization analysis showed hybridization to only two chromosomes, consistent with the G-banded interpretation of i(1p) and i(1q). To the best of our knowledge, this is the first case of isochromosomes 1p and 1q replacing the two normal chromosome 1s. Molecular investigations using markers for chromosome 1 showed inheritance of only one set of paternal alleles and absence of any maternal alleles in the patient. The adverse phenotype of the patient may be due to one or more recessive mutations, genomic imprinting, or a combination of both. ( info) |