HSC Section 8_April 2017

G. Madani, S.E.J. Connor

fenestral otospongiosis but the bony changes usually extend beyond the otic capsule ( Fig. 12 ).

Venous tinnitus

Venous tinnitus may be due to IIH or venous anomalies and variations.

Idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a disease of undefined pathophysiology associated with PT, although it more commonly presents with headache,

tinnitus is prevalent in Paget’s disease (61%) but PT is also recognized. 30 On CT the appearance may mimic a severe case of pericochlear and A middle-aged woman was referred with an asymmetric hearing loss, balance disturbance, head- ache, and right-sided PT. Volume-rendered image from a CT venogram study demonstrates bilateral severe ste- noses of the transverse sinuses (arrowheads), typical of that seen in idiopathic intracranial hypertension. Figure 13

Figure 15 (a) Contrast-enhanced CT study in a patient with venous tinnitus, shows dominant right-sided venous drainage, a laterally deviated right sigmoid sinus, with small sigmoid and jugular diverticulae, and a dehiscent jugular bulb (confirmed on bone windows). (b) A 12- year-old child presented with right-sided hearing loss and PT. A ‘‘blue drum’’ was explored and found to rep- resent a middle ear filled by his only jugular bulb. Fron- tal maximum intensity projection of an MRV study demonstrates markedly right-sided dominant venous drainage with a high-riding jugular bulb.

Figure 14 A 36-year-old woman with PT developed raised intracranial pressure for which she was treated by serial lumbar punctures and diuretics. CT showed a low-density mass in the right jugular foramen (which enhanced peripherally and extended subcranially on MRI studies). This was felt to represent a vagal schwan- noma resulting in venous outflow obstruction and sec- ondary intracranial hypertension.

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