Activation patterns of the primary auditory cortex in normal-hearing subjects: a functional magnetic resonance imaging study.

CONCLUSIONS: These results demonstrate that functional magnetic resonance imaging (fMRI) is an optimal tool to investigate the auditory cortex. The study suggests that there is a medio-lateral gradient of responsiveness to high frequencies medially and low frequencies laterally. The contralateral auditory cortex is more responsive than the ipsilateral cortex to tones presented monaurally. OBJECTIVES: To demonstrate the activation of the primary auditory cortex in normal-hearing subjects using fMRI and to examine the response and topographic location of activation in the human auditory brain to stimulation with two different frequencies in a large group of volunteers. SUBJECTS AND METHODS: Scanning was performed on a 1.5 Tesla MR with head gradient coils and a birdcage radiofrequency coil. Multiplanar echo-planar images were acquired in 32 subjects aged between 18 and 49 years. Two groups were defined, according to age (group A, 18 to <35 years old; group B, 35 to <50 years old). We studied normal-hearing subjects scanned while listening to auditory stimuli: narrative text in one volunteer and non-speech noise (pure tones 750 Hz and pure tones 2 KHz) in all subjects. RESULTS: For both tone frequencies, auditory activation was observed bilaterally across the supratemporal plane in 29 of the 32 subjects (90.62%) with a probability level of p<0.001. In Heschl's gyrus (HG) contralateral to the stimulated ear, the extent of activation was generally greater than in homolateral HG. There were no statistical differences in HG activation according to age or sex. The 750 Hz tone activated more voxels in the medial area of the transverse temporal gyrus (TTG) whereas the 2000 Hz tone activated more voxels in the lateral TTG.

Epiglottitis and necrotizing fasciitis: a life-threatening complication of infectious mononucleosis.

Life-threatening cervical complications associated with infectious mononucleosis are rare. The combination of acute epiglottitis and subsequent necrotizing fasciitis of the head and neck in a patient with infectious mononucleosis has not been reported to date.A 47-year-old female with infectious mononucleosis and epiglottitis was admitted to hospital for i.v. therapy. Owing to her poor clinical condition and the spread of the infection to the throat and superior mediastinum, as evidenced by CT, a cervical debridement was performed. After cervical debridement, histological findings were consistent with necrotizing fasciitis. The bacteria identified were Streptococcus viridans, Veilonella spp. and Capnocytophaga spp. The patient was hospitalized for 33 days.Mononucleosis, usually a benign condition, may be associated with life-threatening septic complications in the neck and chest. Serial CT or MRI scans are necessary to assess the development of the infection in the deep layers of the neck. Rapid medical treatment, extensive surgical debridement and intensive care are vital.

Peripheral primitive neuroectodermal tumour of the left maxillary sinus.

Peripheral primitive neuroectodermal tumours (pPNETs) are highly malignant, small-cell neoplasms found mainly in children and young adults. Recent advances in immunohistochemistry and genetic typing have led to reports of a close relationship between pPNET and the previously difficult-to-classify Ewing's sarcoma. We report a case of pPNET involving the left maxillary sinus in a 23-year-old female who presented with a 2-month history of unilateral left-sided nasal obstruction, rhinorrhoea and recurrent bloody nasal discharge. A CT scan of the paranasal sinuses showed a large mass (10 x 7 x 3 cm3) arising from the left maxillary sinus, with signs of bone destruction and invasion of the left orbital floor and pterygomaxillary fossa. MRI revealed a heterogeneous hyperintense signal on a T2-weighted image in the left maxillary sinus. The tumour was surgically removed by means of external lateral rhinotomy. Pathological examination showed a sheet of small cells with irregular nuclei. Immunohistochemical studies demonstrated positive immunoreactivity for neurone-specific enolase, synaptophysin, chromogranin, vimentin, S-100 protein and p30-32 MIC-2 gene product. The patient was treated with chemotherapy consisting of cyclophosphamide, vincristine, adriamycin and actinomycin D, together with radiotherapy to a total tumour dose of 60 Gy. After 59 months of follow-up, the patient remained free of disease and a repeat MRI scan was normalized, with no sign of residual tumour.