Unilateral sensorineural hearing loss and its aetiology in childhood: the contribution of computerised tomography in aetiological diagnosis and management.
OBJECTIVE
The objective of this study was to identify factors correlated with the CT outcome and to examine the contribution of the CT scan in the aetiological diagnosis and management of unilateral sensorineural hearing loss in childhood.


METHODS
The records of 35 consecutively investigated patients by the Audiology Department of Great Ormond Street Hospital between January 1996 and June 1998 were reviewed. The CT results, population sample characteristics, initiation of further investigations after the CT results and management decisions based on the CT results were tabulated and analysed.


RESULTS
In a series of 35 consecutively investigated children with unilateral sensorineural hearing loss, 11 CT scans were identified as abnormal. The CT findings were: labyrinthitis ossificans (3), unilaterally dilated vestibular aqueduct (2), bilaterally dilated vestibular aqueduct (2), unilateral deformity of the cochlea ('Mondini') (1), unilateral severe labyrinthine dysplasia (1), unilateral markedly narrow internal acoustic meatus (1), bilaterally dilated lateral semicircular canals (1). The presence of progressive hearing loss was a significant predictor of abnormal CT outcome, while the severity of hearing loss was not. The CT scans offered valuable information regarding the aetiological diagnosis in all cases and, in addition, prompted the appropriate vestibular rehabilitation in three cases, further investigations in four (with dilated vestibular aqueduct) and hearing preservation counselling in two (bilateral DVA) (seven out of 35 = 20%).


CONCLUSIONS
All children with unilateral sensorineural hearing loss should have a CT scan of the petrous pyramids/IAMs performed at some stage, as not only aetiology but also prognosis and management of these cases may be significantly influenced by the CT outcome.
Bamiou
D E
DE
Audiology Department, Great Ormond Street Hospital for Sick Children, London, UK. doriseva@ndirect.co.uk
Savy
L
L
O'Mahoney
C
C
Phelps
P
P
Sirimanna
T
T
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000002:abnormalities / Q000000981:diagnostic imaging; D003657:Decision Making; D004108:Dilatation, Pathologic / Q000150:complications / Q000000981:diagnostic imaging; D007758:Ear, Inner / Q000002:abnormalities / Q000000981:diagnostic imaging; D005260:Female; D005544:Forecasting; D006319:Hearing Loss, Sensorineural / Q000000981:diagnostic imaging / Q000209:etiology* / Q000628:therapy; D006801:Humans; D007759:Labyrinth Diseases / Q000150:complications / Q000000981:diagnostic imaging; D007762:Labyrinthitis / Q000150:complications / Q000000981:diagnostic imaging; D008297:Male; D009999:Ossification, Heterotopic / Q000150:complications / Q000000981:diagnostic imaging; D010347:Patient Care Planning; D010579:Petrous Bone / Q000000981:diagnostic imaging; D011379:Prognosis; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014723:Vestibular Aqueduct / Q000000981:diagnostic imaging; D015837:Vestibular Diseases / Q000150:complications / Q000000981:diagnostic imaging