Since Gradenigo first described his classic triad, numerous authors have endeavored to offer explanations for this condition. Careful histologic study has added much to the knowledge of disturbances of the temporal bone.
It is known that at least 80 per cent of the patients with Gradenigo's syndrome recover following simple mastoidectomy. In the 20 per cent who succumb, histopathologic study reveals that suppuration of the apex of the petrous portion of the temporal bone is more frequent than has been suspected.
It has been argued by many that Gradenigo's syndrome is not a distinct clinical entity, owing to the lack of adequate anatomic and pathologic bases. Numerous attempts have been made to show that palsy of the sixth nerve is due to involvement in Dorello's canal (Vail1 and others), to venous congestion (Freisner and Druss,2 Ruskin,3 and others) or to localized meningeal irritation (Eagleton4).
COATES GM, ERSNER MS, MYERS D. ROENTGEN CHANGES IN THE PETROUS PORTION OF THE TEMPORAL BONE WITHOUT CLINICAL MANIFESTATIONS. Arch Otolaryngol. 1934;20(5):615–648. doi:10.1001/archotol.1934.03600050002001