OBJECTIVE: To compare the auditory steady-state response (ASSR) test data of severe sensorineural hearing loss children with cochlear lesion and those with retrocochlear lesion and find some specific phenomena of retrocochlear lesion in ASSR, then to improve diagnostic accuracy in clinical practice. METHOD: Between 2008 to 2012. 96 children (179 ears) were diagnosed with "retrocochlear auditory nerve lesion" and recieved ASSR test (" retrocochlear lesion" group). Eighty-one (143 ears) the same age children (143 ears) were diagnosed as "cochlear auditory nerve lesion" and selected them as the "cochlear lesion" group. Twenty-six (50 ears) normal hearing children at the same age who had ASSR test records selected from the pediatric hearing center database of our hospital were selected as "normal control" group. Compare the difference of ASSR threshold, ASSR elicit rate and ASSR audiogram among the three groups. RESULT: (1) ASSR threshold: Compared each frequency threshold in ASSR test with cochlear.lesion group, the retrocochlear lesion group with wave V and wave I had no significant difference in 500 Hz and 1000 Hz but had significant difference in 2000 Hz and 4000 Hz. As for the retrocochlear lesion group without wave V and wave I, there was a decline in 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz compared with cochlear lesion group. (1) ASSR elicit rate: When compared to retrocochlear lesion group, the cochlear lesion group had a significance lower elicit rate in the four frequency. (3) Number of elicit reactions in ASSR test . In the retrocochlear lesion group, the elicit reactions in all the four frequency in ASSR test was significantly higher than ochlear lesion group. (4) ASSR audiogram type. The proportion of rising curve audiogram in retrocochlear lesion group was 26.83% (with wave I and wave V), 40% (with wave I and without wave V ) and 33.80% (without wave I and wave V). CONCLUTION (1) Children with a severe hearing loss in ABR test and a rise type audiogram in ASSR test should be most possibly considered as retrocochlear lesion. (2) ASSR threshold cannot be used in determinate the severity of hearing loss in children with retrocochlear lesion.
Auditory Threshold ; Child ; Cochlea ; pathology ; Hearing Loss, Sensorineural ; diagnosis ; Hearing Tests ; Humans ; Labyrinth Diseases ; Vestibulocochlear Nerve Diseases ; diagnosis

In most cases, while schwannoma is sporadically manifested as a single benign neoplasm, the presence of multiple schwannomas in one patient is usually indicative of neurofibromatosis 2. However, several recent reports have suggested that schwannomatosis itself may also be a distinct clinical entity. This study examines an extremely rare case of probable schwannomatosis associated with intracranial, intraspinal and peripheral involvements. A 63-year-old woman presented with a seven-year history of palpable lumps on both sides of the supraclavicular area and hearing impairment in both ears. On physical examination, no skin manifestations were evident. Facial sensory change, deafness in the left ear and decreased gag reflex were revealed by neurological examination. Magnetic resonance imaging revealed multiple lesions of the trigeminal nerves, acoustic nerves, lower cranial nerves, spinal accessory nerve, brachial plexuses, and spinal nerves. Pathological examination of tumors from the bilateral brachial plexuses, the spinal nerve in the T8 spinal position and the neck mass revealed benign schwannomas. Following is this patient case report of multiple schwannomas presenting with no skin manifestations of neurofibromatosis.
Brachial Plexus Neuropathies/*pathology/surgery ; Case Report ; Cranial Nerve Neoplasms/*pathology/surgery ; Female ; Human ; Magnetic Resonance Imaging ; Middle Age ; Neurilemmoma/*pathology/surgery ; Neurofibromatoses/*pathology ; Spinal Canal/*pathology ; Trigeminal Nerve Diseases/*pathology/surgery ; Vestibulocochlear Nerve Diseases/*pathology/surgery

A very rare case of multiple primary intracranial tumors is reported. A 41-year-old female patient was referred for surgery with a cerebellopontine angle (CPA) tumor. Medical history and MRI study showed typical findings of a right acoustic neuroma with a hydrocephalus. Neurological, dermatological, and ocular examinations revealed no evidence of neurofibromatosis. During surgery, a red-colored cauliflower like mass was found in the right CPA. The roof of the fourth ventricle could be seen through the lateral recess after removal of the tumor. Another mass, a 1.5-cm sized schwannoma protruding through the right internal auditory meatus, was removed by the transmeatal approach. Although the tumor masses were in contact and compressed against each other, there was a clear demarcation between them. Histological examination confirmed that the first mass was a typical choroid plexus papilloma with fibrovascular core, and that the second was a schwannoma. The patient recovered without any new neurological deficit. Result of a Medline search indicated that this rare combination of multiple primary tumors has not been reported previously.
Adult ; Case Report ; Choroid Plexus Neoplasms/*pathology ; Female ; Human ; Magnetic Resonance Imaging ; Neoplasms, Multiple Primary/*pathology ; Neurilemmoma/*pathology ; Papilloma/*pathology ; Vestibulocochlear Nerve Diseases/*pathology

OBJECTIVETo access the pathological changes of the functional localization of the primary auditory cortex in auditory neuropathy patients using magnetoencephalography (MEG).

METHODSThe M100 waves of cortical evoked magnetic fields (AEF) evoked by 0.5, 1, 2, 4, 6, 8 kHz pure tones were measured respectively in 10 auditory neuropathy patients (20 ears) and 15 healthy young subjects (30 ears) using a whole head 306 channel magnetoencephalography (MEG) system. The auditory cortex magnetic source imaging obtained by superimposing functional MEG data on structural magnetic resonance image (MRI).

RESULTSThe M100 sources were obtained in all 15 healthy young subjects in all frequency except for 8 kHz in 16 ears. But in auditory neuropathy patients, the ratio of M100 from 0.5 to 6 kHz were 27.5% (11/40), 22.5% (9/40), 7.5% (3/40), 5% (2/40), 5% (2/40) respectively and no any waves in 8 kHz. The evoked ratio of M100 in low frequency was high and that decreased gradually with increasing of evoked pure tone frequency. The M100 latentencies and amplitudes were longer and lower in patient group than that in control group (P < 0.01).

CONCLUSIONSAuditory neuropathy is an audiology disease with pathological lesions from the VIII cranial nerve to auditory cortex. MEG might become an important reference in decision making for therapies.

Adolescent ; Auditory Cortex ; pathology ; physiopathology ; Case-Control Studies ; Cerebral Cortex ; pathology ; physiopathology ; Evoked Potentials, Auditory ; Female ; Humans ; Magnetoencephalography ; Male ; Vestibulocochlear Nerve Diseases ; pathology ; physiopathology ; Young Adult

Cochlear Nerve ; chemistry ; pathology ; Cranial Nerve Neoplasms ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Heart Neoplasms ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Middle Aged ; Neoplasms, Multiple Primary ; metabolism ; pathology ; Neurilemmoma ; metabolism ; pathology ; S100 Proteins ; metabolism ; Vestibulocochlear Nerve Diseases ; metabolism ; pathology ; Vimentin ; metabolism

BACKGROUNDMost patients with auditory neuropathy (AN) could receive good even the best effects after cochlear implantation. How to diagnose AN objectively and accurately is very important. In this study, we screened the patients with AN according to the presence or absence of compound action potential (CAP) of intraoperative round window electrocochleography (RW ECochG).

METHODSIntraoperative RW ECochG was performed on 32 patients with profound sensorineural deafness, who had normal cochlea during cochlear implantation surgery under general anesthesia in the standard operating room. The cochlear microphonic (CM) and CAP of RW ECochG was observed and recorded.

RESULTSThe presence of CM but the absence of CAP of RW ECochG occurred in 12 among the 32 patients. They were suspected to suffer from AN. The rest patients who had CM and CAP of RW ECochG were thought not to suffer from AN.

CONCLUSIONApplication of intraoperative RW ECochG during the cochlear implantation surgery may objectively and accurately screen the patients with AN, and can give a meaningful clue for implanted device working.

Adolescent ; Adult ; Audiometry, Evoked Response ; methods ; Child ; Child, Preschool ; Cochlear Nerve ; pathology ; Electrophysiology ; methods ; Evoked Potentials ; Female ; Humans ; Infant ; Male ; Round Window, Ear ; Vestibulocochlear Nerve Diseases ; diagnosis ; Young Adult