1/154. Contralateral deafness following unilateral suboccipital brain tumor surgery in a patient with large vestibular aqueduct--case report.A 68-year-old female developed contralateral deafness following extirpation of a left cerebellopontine angle epidermoid cyst. Computed tomography showed that large vestibular aqueduct was present. This unusual complication may have been caused by an abrupt pressure change after cerebrospinal fluid release, which was transmitted through the large vestibular aqueduct and resulted in cochlear damage.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
2/154. Intraoperative loss of auditory function relieved by microvascular decompression of the cochlear nerve.BACKGROUND: Brainstem auditory evoked potentials (BAEP) are useful indicators of auditory function during posterior fossa surgery. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. We report two cases of intraoperative auditory loss related to vascular compression upon the cochlear nerve. methods: Intra-operative BAEP were monitored in a consecutive series of over 300 microvascular decompressions (MVD) performed in a recent twelve-month period. In two patients undergoing treatment for trigeminal neuralgia, BAEP waveforms suddenly disappeared completely during closure of the dura. RESULTS: The cerebello-pontine angle was immediately re-explored and there was no evidence of hemorrhage or cerebellar swelling. The cochlear nerve and brainstem were inspected, and prominent vascular compression was identified in both patients. A cochlear nerve MVD resulted in immediate restoration of BAEP, and both patients recovered without hearing loss. CONCLUSION: These cases illustrate that vascular compression upon the cochlear nerve may disrupt function, and is reversible with MVD. awareness of this event and recognition of BAEP changes alert the neurosurgeon to a potential reversible cause of hearing loss during posterior fossa surgery.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
3/154. Progressive ponto-bulbar palsy with deafness. A clinico-pathological study.Progressive ponto-bulbar palsy with deafness is a rare disease. It seems to be an abiotrophic process with autosomal recessive inheritance in most instances. Only one autopsy case had been briefly described (Lelong et al., 1941). The clinical features and the pathological findings of a new case are reported. The structures primarily involved are the grey matter of the brain stem and the spinal cord, including to some extent the optic tracts and most of the fiber tracts in the brain stem with exception of the pyramidal tracts.- - - - - - - - - - ranking = 0.5keywords = brain (Clic here for more details about this article) |
4/154. 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.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
5/154. 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.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
6/154. 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.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
7/154. 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.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
8/154. Genetic factors in human sleep disorders with special reference to Norrie disease, prader-willi syndrome and Moebius syndrome.Sleep-wake problems are common in specific inborn errors of metabolism and structure of the central nervous system. Psychological factors, behavioural difficulties, metabolic disturbances, and widespread rather than focal damage to the nervous system are present in many of these diseases and all influence the sleep-wake cycle. However, a number of conditions cause relatively focal damage to the neuroanatomical substrate of sleeping and waking. These include fatal familial insomnia, with involvement of the prion protein gene on chromosome 20, Norrie disease, the prader-willi syndrome and the Moebius syndrome. The last three important conditions, although rare, are considered in detail in this review. They result in sensory deprivation, hypothalamic and mid-brain damage, and involve the X-chromosome, chromosome 15, and chromosome 13, respectively. These conditions cause a wide variety of sleep disturbance, including parasomnias, daytime sleepiness, and a condition like cataplexy. The place of the relevant gene products in normal sleep regulation needs further exploration.- - - - - - - - - - ranking = 1.3848384655754keywords = central nervous system, nervous system, brain (Clic here for more details about this article) |
9/154. Auditory rehabilitation in neurofibromatosis type 2: a case for cochlear implantation.cochlear implantation has a limited but definite role in the rehabilitation of certain neurofibromatosis type 2 (NF2) patients. The presence of a dead ear either before, or after, tumour removal does not necessarily imply loss of function in the eighth nerve; in some instances the hearing loss will be cochlear. Promontory or round window electrical stimulation may help to identify those individuals with surviving eighth nerve function. In such patients multichannel cochlear implantation promises a better level of audition than the auditory brain stem implant. This paper highlights such a case and the management problems are discussed.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
10/154. Bilateral sensorineural deafness, partial agenesis of the corpus callosum, and arachnoid cysts in two sisters.We describe two sisters (ages 10 and 3 years, respectively) with a normal development and a combination of congenital sensorineural hearing loss, partial agenesis of the corpus callosum, arachnoid cyst, and hydrocephalus. Neither girl has distinctive physical anomalies. In the oldest girl, there was a hearing loss of 80 dB bilaterally, and the most severe loss on audiogram was seen at 2,000-4,000 Hz. In the youngest girl, there was a hearing loss of 100 dB bilaterally. Above 2,000 Hz no neural reactions were seen. Cerebral magnetic resonance imaging in one girl and computed tomography in the other showed a partial agenesis of the corpus callosum and a cyst in the pineal region, causing an aqueduct stenosis by compression and consequent hydrocephalus. The parents have normal hearing, and brain magnetic resonance imaging showed no abnormalities. They are nonconsanguineous but from the same small village. This is the first report of a combination of congenital sensorineural hearing loss, partial agenesis of the corpus callosum, and an arachnoid cyst. The pattern of inheritance is probably autosomal recessive.- - - - - - - - - - ranking = 0.25keywords = brain (Clic here for more details about this article) |
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