Tinnitus

• Incidence 10-20% of population

• Pulsatile vs non-pulsatile

Aetiology

Non-pulsatile

• Hearing loss (Most common by far)

Pulsatile

Common causes

• Unknown 23%

• Arterial stenoses 18%

• Intracranial hypertension 16%

• Venous anatomical variant 12%

• Other 8%

• Dural AVF 7%

• Vessel rich tumour (AV connection) 6%

• Arterial anatomical variants 4%

• Capillary hyperaemia 3%

• Direct AVF 2%

• Aneurysm 1%

Full list

• Tumour

o Paraganglioma (most common)

- Glomus typanicum or glomus jugulare (auricular branch of nerve)

o Meningioma

o Endolymphatic sac tumour

o Other skull base tumours

• Vascular – Arterial

o Aberrant ICA

o Persistence of stapedial artery

o ICA dehiscence

o Persistent trigeminal artery

o Arterial stenosis or dissection

o Dural AVF

o Aneurysm (very rare)

o Vascular loop in IAM (non a proven link)

• Vascular – venous

o Transverse sinus stenosis

- Intrinsic (Arachnoid granulation/thrombosis)

- Extrinsic (IIH)

o Sigmoid sinus wall anomalies (dehiscence or diverticulum) - ?very common cause

- Outpouching of sigmoid sinus into mastoid

o Emissary vein enlargement

o Jugular bulb abnormalities (most probably incidental)

- High riding jugular bulb (above level of IAM)

- Dehiscence

• Bone abnormalities/dysplasia

o Otospongiosis

o Paget;s

o Facial nerve venous malformation

o Superior semicircular canal dehiscence

Diagnosis

• Bruit on auscultation - ?arterial cause

• Cessation of tinnitus with compression of IJV – venous cause

Investigation

Imaging

• Depends on cause

• Low yield in standard tinnitus

• Higher yield if unilateral hearing loss or pulsatile

• Pulsatile:

o MRA/MRV

o CT skull base

References

Review article

Pulsatile Tinnitus

Imaging and Differential Diagnosis

Dtsch Arztebl Int 2013; 110(26): 451-8. DOI: 10.3238/arztebl.2013.0451