Facial nerve paralysis associated with temporal bone masses.
OBJECTIVE
To investigate the clinical and electrophysiological features of facial nerve paralysis (FNP) due to benign temporal bone masses (TBMs) and elucidate its differences as compared with Bell's palsy.


METHODS
FNP assessed by the House-Brackmann (HB) grading system and by electroneurography (ENoG) were compared retrospectively.


RESULTS
We reviewed 914 patient records and identified 31 patients with FNP due to benign TBMs. Moderate FNP (HB Grades II-IV) was dominant for facial nerve schwannoma (FNS) (n=15), whereas severe FNP (Grades V and VI) was dominant for cholesteatomas (n=8) and hemangiomas (n=3). The average ENoG value was 19.8% for FNS, 15.6% for cholesteatoma, and 0% for hemangioma. Analysis of the correlation between HB grade and ENoG value for FNP due to TBMs and Bell's palsy revealed that given the same ENoG value, the corresponding HB grade was better for FNS, followed by cholesteatoma, and worst in Bell's palsy.


CONCLUSIONS
Facial nerve damage caused by benign TBMs could depend on the underlying pathology. Facial movement and ENoG values did not correlate when comparing TBMs and Bell's palsy. When the HB grade is found to be unexpectedly better than the ENoG value, TBMs should be included in the differential diagnosis.
Department of Otolaryngology- Head and Neck surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan. Electronic address: nishijimahironobu@gmail.com.
Hironobu
H
Nishijima
Department of Otolaryngology- Head and Neck surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan.
Kenji
K
Kondo
Department of Otolaryngology- Head and Neck surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan.
Ryoji
R
Kagoya
Department of Otolaryngology- Head and Neck surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan.
Hitoshi
H
Iwamura
Department of Otolaryngology- Head and Neck surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan.
Kazuo
K
Yasuhara
Department of Otolaryngology- Head and Neck surgery, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8655, Japan.
Tatsuya
T
Yamasoba
D000293:Adolescent; D000328:Adult; D000368:Aged; D020330:Bell Palsy / Q000209:etiology; D002781:Cholesteatoma / Q000150:complications; D003390:Cranial Nerve Neoplasms / Q000150:complications*; D004568:Electrodiagnosis; D005155:Facial Nerve Diseases / Q000150:complications*; D005158:Facial Paralysis / Q000209:etiology*; D005260:Female; D006391:Hemangioma / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000150:complications; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012888:Skull Neoplasms / Q000150:complications*; D013701:Temporal Bone; D055815:Young Adult
Bell palsy,; Electroneurography; Facial nerve paralysis; Schwannoma; Temporal bone tumor