11/71. Functional role of the human inferior colliculus in binaural hearing.Psychophysical experiments were carried out in a rare case involving a 48 year old man (RJC) with a small traumatic hemorrhage of the right dorsal midbrain, including the inferior colliculus (IC). RJC had normal audiograms bilaterally, but there was a marked decrease in wave V amplitude on click-evoked brainstem auditory evoked potentials following left ear stimulation. RJC demonstrated a deficit in sound localization identification when the loudspeakers lay within the auditory hemifield contralateral to his IC lesion. Errors showed a consistent bias towards the hemifield ipsilateral to the lesion. Echo suppression was abnormally weak compared with that seen in control subjects, but only for sources contralateral to the lesion. Finally, speech intelligibility tests showed normal ability to benefit from spatial separation of target and competing speech sources. These results suggest that: (1) localizing sounds within a given hemifield relies on the integrity of the contralateral IC, (2) unilateral IC lesions give the illusion that sound sources in the 'bad' hemifield are displaced towards the 'good' hemifield, (3) the IC mediates aspects of echo suppression, and (4) lesion in the IC does not impede spatial release from masking in speech intelligibility, possibly due to that ability being more heavily mediated by cortical regions.- - - - - - - - - - ranking = 1keywords = speech (Clic here for more details about this article) |
12/71. Multiple cavernomas of brain presenting with simultaneous hemorrhage in two lesions: a case report.BACKGROUND: Cavernomas are rare vascular lesions of the brain that can bleed. However, the risk of bleeding is lower than that of aneurysms or arteriovenous malformations. In selected cases, bleeding cavernomas require surgical management. Presented here is a case of multiple cavernomas of the brain with simultaneous bleeding in two different lesions, along with its management. Although multiple cavernomas have been described in the literature, simultaneous bleeding in two different lesions is rare. CASE DESCRIPTION: A 52-year-old woman presented with difficulty maintaining balance, double vision, and slurred speech. She had had multiple surgeries for cavernous angioma of the brain in the past. Examination and investigations revealed two cavernomas, one in the dorsal midbrain region and one in the left occipital region. Her clinical condition deteriorated suddenly, and further evaluation revealed bleeding in both the cavernomas.The lesion in the midbrain was removed surgically. Since the lesion was in the posterior midbrain, a posterior interhemispheric approach was used with the help of frameless stereotactic navigation. Total excision was achieved. The lesion in the occipital lobe was not operated on.The patient had an uneventful recovery. It was planned to observe the progress of the occipital cavernoma by serial magnetic resonance imaging scans. CONCLUSION: Although there may be simultaneous bleeding in two or even more lesions, surgical treatment should be undertaken for the lesions jeopardizing critical structures or exerting mass effects. Additionally, it was discovered that frameless stereotactic navigation was of immense help in delineating the lesion and for safe excision of the lesion in critical areas.- - - - - - - - - - ranking = 0.33333333333333keywords = speech (Clic here for more details about this article) |
13/71. Accidental pneumothorax from a nasogastric tube in a patient with severe hemineglect: a case report.Nasogastric tubes are frequently used for nutrition of patients with neurologic diseases. We report an instance of inadvertant placement of a standard nasogastric tube into the left pleural space in a patient with right parietotemporal intracerebral hemorrhage and severe hemineglect on the left side. The 2 confirmatory maneuvers-aspiration of fluid and auscultating the abdomen on insufflating air-were false-positive. We conclude that only radiologic confirmation of the position of nasogastric tubes and the awareness of the associated dangers will help minimize the occurrence of such events in patients with disorders of perception or altered consciousness.- - - - - - - - - - ranking = 0.15384441591298keywords = perception (Clic here for more details about this article) |
14/71. Amorphosynthesis on the chess board.Visual spatial perception difficulities on the chest board have been studied in a patient with a dominant hemisphere infarction. The game of chess can be useful to demonstrate and follow the evolution of amorphosynthesis.- - - - - - - - - - ranking = 0.15384441591298keywords = perception (Clic here for more details about this article) |
15/71. A new sign of callosal disconnection syndrome: agonistic dyspraxia. A case study.We report a patient with callosal haemorrhage and no extracallosal involvement who developed a unique form of intermanual conflict. In the acute phase the patient showed a mild speech disturbance and right hemiparesis, and in her right hand, a grasp reflex and compulsive manipulation of tools, all attributable to transient frontal involvement. In the chronic phase there was intermanual conflict occasionally associated with the sensation of a second left hand. The patient also presented a sign consisting of compulsive, automatic execution of orders by one hand (the left or the right) when the patient was specifically asked to perform the movement with the other hand (the right or the left, respectively). There was no left-right confusion in this patient. We call this condition agonistic dyspraxia. In contrast with diagonistic dyspraxia, this consists of the agonistic behaviour of the other hand under conditions in which the hand that has been instructed to respond cannot execute the request.- - - - - - - - - - ranking = 0.33333333333333keywords = speech (Clic here for more details about this article) |
16/71. Crossed aphasia with left spatial neglect and visual imperception: a case report.A 64-year-old right-handed woman with no left-handers in the family developed aphasia associated with moderate left hemiparesis and dense left homonymous hemianopia following rupture of a right middle cerebral artery aneurysm and subsequent selective surgery confined to the right hemisphere. Severe left spatial neglect and constructional apraxia were also present. The patient was an achondroplasic dwarf whose previous medical and neurological history was otherwise unremarkable. Computed tomography of the brain showed a large right temporo-insulofrontoparietal lesion. language and nonverbal cognitive functions were assessed after 2 and 6 months, and then four years later. A reportedly overall language disruption in the acute period evolved into Wernicke's aphasia and then into a mild form of conduction aphasia. The associated left spatial neglect eventually shrank to a minimum. The patient never had clinically detectable visual agnosia, but on specific tests of visual recognition and perception some impairment was found four years after onset. The left hemiparesis disappeared in time while the left hemianopia persisted. This case is a convincing example of an entirely righthanded person in whom both linguistic and visuospatial functions are represented in the right hemisphere.- - - - - - - - - - ranking = 0.76922207956488keywords = perception (Clic here for more details about this article) |
17/71. Phonemic characteristics of apraxia of speech resulting from subcortical hemorrhage.Reports describing subcortical apraxia of speech (AOS) have received little consideration in the development of recent speech processing models because the speech characteristics of patients with this diagnosis have not been described precisely. We describe a case of AOS with aphasia secondary to basal ganglia hemorrhage. Speech-language symptoms consistent with subcortical AOS and aphasia are reported as well as description of the patient's speech characteristics using broad phonemic transcription. Significantly more phoneme substitution errors were observed than other types of errors and these occurred significantly more often in the initial rather than the medial or final positions of words. No differences were observed in the number of errors produced for the various types of phonemes included in this analysis. These findings challenge the hypothesis that speech motor planning disorders are uniquely the result of cortical damage. They also argue against the notion that subcortical AOS is indistinguishable from the cortical syndrome. learning OUTCOMES: The reader will learn (1) the phonemic characteristics of AOS due to subcortical brain damage, (2) the similarities and differences between AOS due to cortical versus subcortical lesions, and (3) the implications of these patterns for current models of speech motor processing.- - - - - - - - - - ranking = 3.3333333333333keywords = speech (Clic here for more details about this article) |
18/71. Sensorineural hearing loss and word deafness caused by a mesencephalic lesion: clinicoelectrophysiologic correlations.OBJECTIVE: To assess the role of inferior colliculi as a generator of Wave V of brainstem auditory evoked potentials and in modulating the olivocochlear efferent auditory system. STUDY DESIGN: Case review. SETTING: University and tertiary referral centers. patients: Case report of a patient with word deafness caused by mesencephalic hemorrhage according to audiologic and electrophysiologic findings. RESULTS: The patient is a 48-year-old woman who suffered word deafness caused by hemorrhage localized at the quadrigeminal plate (including the inferior colliculi). At a follow-up visit, her pure-tone audiogram revealed symmetric severe sensorineural hearing loss that had partially resolved, whereas speech audiometry showed persistent word deafness. Acoustic reflexes were elicited, with normal thresholds bilaterally. Transient evoked otoacoustic emissions were recorded from both ears, with normal response and signal-to-noise ratio, but there was a failure for their amplitude to be suppressed with contralateral sound stimulation. Brainstem auditory evoked potentials were of normal amplitude and latencies bilaterally. CONCLUSION: The finding of normal brainstem auditory evoked potentials supports the view that the neural generator of Wave V lies caudally to the inferior colliculi. Moreover, the abnormal suppression of transient evoked otoacoustic emissions indicates that descending collicular input is capable of modulating levels of excitability within the olivary nucleus and the cochlea.- - - - - - - - - - ranking = 0.33333333333333keywords = speech (Clic here for more details about this article) |
19/71. Regular and irregular morphology and its relationship with agrammatism: evidence from two Spanish-Catalan bilinguals.We report the performance of two aphasic patients in a morphological transformation task. Both patients are Spanish-Catalan bilingual speakers who were diagnosed with agrammatic Broca's aphasia. In the morphological transformation task, the two patients were asked to produce regular and irregular verb forms. The patients showed poorer performance with irregular than regular morphological transformations in both of their languages. These results are at odds with the proposal that agrammatic speech is always or even preponderantly associated with poorer performance in processing regular versus irregular verb form. Instead, these results support the view that a major component of agrammatic production is a deficit in morphosyntactic processing, independently of whether this processing ultimately involves regular or irregular forms.- - - - - - - - - - ranking = 0.33333333333333keywords = speech (Clic here for more details about this article) |
20/71. Different perceived foreign accents in one patient after prerolandic hematoma.Foreign accent syndrome (FAS), a rare disorder characterized by the emergence of a new accent perceived as foreign by listeners, is usually reported with left brain damage. We here report the case of a 28-year-old native Brazilian who appeared, to the examiner, to show a North American accent during recovery from Broca's aphasia. The lesion was due to a frontal hematoma. Without referring specifically to speech, we asked 10 independent observers to comment on a videotape of the patient's interview. Seven reported that the patient had a foreign accent, while 3 simply noted a 'strange' accent. The observers did not agree on the origin of the accent, 5 identifying it as Spanish, 1 as German, and 1 as south Brazilian. These findings suggest that FAS is not due to the acquisition of a specific foreign accent, but to impairment of the suprasegmental linguistic abilities (tone, accent, pauses, rhythm, and vocal stress) that make it possible to distinguish native language.- - - - - - - - - - ranking = 0.33333333333333keywords = speech (Clic here for more details about this article) |
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