Projection of the cochlear nuclei on the inferior colliculus in the cat

Degeneration in brainstem auditory nuclei was studied in monkeys following chronic implantation with scala tympani multielectrode systems. Nauta and Fink/Heimer-stained material from animals with survival × to 16 months were studied. The density and distribution of degeneration in the cochlear nuclei were consistent with observed patterns of spiral ganglion cell degeneration. Transneuronal degeneration was seen up to the level of the inferior colliculus. The density and form of the degeneration material in animals of varying survival times was consistent with the interpretation that a process of continuing degeneration occurred in these implanted ears.

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Descending auditory pathways: Projections from the inferior colliculus contact superior olivary cells that project bilaterally to the cochlear nuclei

The Journal of Comparative Neurology ◽

10.1002/(sici)1096-9861(19990628)409:2<210::aid-cne3>3.0.co;2-a ◽

1999 ◽

Vol 409 (2) ◽

pp. 210-223 ◽

Cited By ~ 48

Author(s):

Brett R. Schofield ◽

Nell B. Cant

Keyword(s):

Inferior Colliculus ◽

Auditory Pathways ◽

Cochlear Nuclei

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Auditory Brainstem Implantation: Anatomy and Approaches

Operative Neurosurgery ◽

10.1227/neu.0000000000000736 ◽

2015 ◽

Vol 11 (2) ◽

pp. 306-321 ◽

Cited By ~ 10

Author(s):

Noritaka Komune ◽

Kaan Yagmurlu ◽

Satoshi Matsuo ◽

Koichi Miki ◽

Hiroshi Abe ◽

...

Keyword(s):

Inferior Colliculus ◽

Neurofibromatosis Type ◽

Auditory Brainstem ◽

Electrode Placement ◽

Auditory Pathways ◽

Cochlear Nuclei ◽

Endoscopic Assistance ◽

Inferior Collicular ◽

Dissection Technique ◽

Inferior Colliculi

Abstract BACKGROUND Auditory brainstem implantation at the cochlear nuclei used mainly for neurofibromatosis type 2 patients with bilateral loss of the cochlear nerves has more recently been extended to the inferior colliculus. OBJECTIVE To examine the microsurgical and endoscopic anatomy of the cochlear nuclei and inferior colliculus as seen through the translabyrinthine and retrosigmoid approaches used for cochlear nuclei and inferior collicular implantation. METHODS Ten cerebellopontine angles of formalin-fixed adult cadaveric heads were examined with the aid of the surgical microscope and endoscope. The ascending auditory pathways between the cochlear nuclei and inferior colliculi and above were examined by the fiber dissection technique. RESULTS Both the translabyrinthine and retrosigmoid routes provide sufficient exposure for concurrent tumor removal and implantation at either the cochlear nuclei or inferior colliculus. The position of the inferior colliculus in the auditory pathways and its accessibility in the infratentorial supracerebellar exposure directed through either the translabyrinthine or retrosigmoid approach makes it an alternative site for electrode placement if the cochlear nuclei are not functionally or structurally suitable for implantation. Endoscopic assistance may aid the exposure and electrode placement at either site. CONCLUSION The translabyrinthine or retrosigmoid approaches provide access to the cochlear nuclei for implantation and also to the inferior colliculus through the translabyrinthine or retrosigmoid infratentorial supracerebellar route. The endoscope may aid in exposing either site.

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