TY - JOUR
T1 - Pontine tegmental cap dysplasia
T2 - The neurotologic perspective
AU - Desai, Nilesh K.
AU - Young, Lindsay
AU - Miranda, Mario A.
AU - Kutz, Joe Walter
AU - Roland, Peter S.
AU - Booth, Timothy N.
PY - 2011/12
Y1 - 2011/12
N2 - Objectives. Pontine tegmental cap dysplasia (PTCD) is a rare congenital malformation. Clinical and imaging findings in 3 patients and the authors' experience with bilateral cochlear implantation in 1 patient are described. Study Design. Retrospective review. Setting. Two tertiary medical centers. Subjects and Methods. Three patients were evaluated by an otolaryngologist and underwent magnetic resonance imaging (MRI) of the temporal bones and brain. High-resolution computed tomography (CT) scanning of the temporal bones was performed in 2 patients. Imaging findings of the brain, the presence and course of resolvable cranial nerves, the membranous labyrinth, and internal auditory canals were reviewed. Clinical data were reviewed. Results. All patients demonstrated typical brain characteristics of PTCD. Mild, bilateral cochlear dysplasia was noted in 2, and all had a normal vestibular labyrinth. The cochleovestibular nerves were universally absent bilaterally. The facial nerves were subjectively deficient bilaterally in 1 patient, unilaterally in the second patient, and normal in the third. An accessory canal for the seventh cranial nerve, referred to as a duplicated internal auditory canal, was present in all patients. Auditory brainstem response testing revealed profound bilateral sensorineural hearing loss in all of the patients; none suffered facial weakness. A single patient underwent bilateral cochlear implantation with only minimal response. Conclusion. The authors report 3 cases of PTCD with emphasis on imaging of the seventh and eighth cranial nerves and clinical neurotologic findings. All patients manifested duplicated internal auditory canals, a previously unreported finding in PTCD. Bilateral profound sensorineural hearing loss is due to absence of the cochleovestibular nerve. Prognosis for cochlear implantation is poor.
AB - Objectives. Pontine tegmental cap dysplasia (PTCD) is a rare congenital malformation. Clinical and imaging findings in 3 patients and the authors' experience with bilateral cochlear implantation in 1 patient are described. Study Design. Retrospective review. Setting. Two tertiary medical centers. Subjects and Methods. Three patients were evaluated by an otolaryngologist and underwent magnetic resonance imaging (MRI) of the temporal bones and brain. High-resolution computed tomography (CT) scanning of the temporal bones was performed in 2 patients. Imaging findings of the brain, the presence and course of resolvable cranial nerves, the membranous labyrinth, and internal auditory canals were reviewed. Clinical data were reviewed. Results. All patients demonstrated typical brain characteristics of PTCD. Mild, bilateral cochlear dysplasia was noted in 2, and all had a normal vestibular labyrinth. The cochleovestibular nerves were universally absent bilaterally. The facial nerves were subjectively deficient bilaterally in 1 patient, unilaterally in the second patient, and normal in the third. An accessory canal for the seventh cranial nerve, referred to as a duplicated internal auditory canal, was present in all patients. Auditory brainstem response testing revealed profound bilateral sensorineural hearing loss in all of the patients; none suffered facial weakness. A single patient underwent bilateral cochlear implantation with only minimal response. Conclusion. The authors report 3 cases of PTCD with emphasis on imaging of the seventh and eighth cranial nerves and clinical neurotologic findings. All patients manifested duplicated internal auditory canals, a previously unreported finding in PTCD. Bilateral profound sensorineural hearing loss is due to absence of the cochleovestibular nerve. Prognosis for cochlear implantation is poor.
KW - Cochlear implant
KW - Duplicated internal auditory canal
KW - Molar tooth
KW - PTCD
KW - Pontine tegmental cap dysplasia
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U2 - 10.1177/0194599811412729
DO - 10.1177/0194599811412729
M3 - Article
C2 - 21705787
AN - SCOPUS:84856068323
SN - 0194-5998
VL - 145
SP - 992
EP - 998
JO - Otolaryngology - Head and Neck Surgery
JF - Otolaryngology - Head and Neck Surgery
IS - 6
ER -