Objectives Intracranial vascular malformations occur in 0.1% of the population with 10%–15% of these attributed to dural arterial-venous fistula (dAVF). It has been suggested that thalamic dementia is potentially underappreciated in dAVF’s. The incidence of potentially reversible thalamic dementia in patients with dAVF’s is unknown, with the literature reporting an incidence from as low as 0% and as high as 11%. To date, there have only been 19 published cases of thalamic dementia secondary to dAVF’s. Digital subtraction angiography (DSA) remains the gold standard for diagnosing dAVF’s. However, MRI wi th susceptibility weighted imaging (SWI) sequences have been found to have a sensitivity of 75% in detecting dAVF’s and could provide unique information regarding their characteristics.

Case A 68 year old male presented with change in behaviour, personality, cognitive and gait impairment resulting in falls, 4 months prior to admission. Clinical examination was characterised by impaired gait and cognitive impairment with ACE-R score of 77/100 with decreased fluency, memory and attention. MRI brain showed swollen thalami with micro-haemorrhages clustered around the basal ganglia and thalami. Further evaluation with DSA excluded underlying venous sinus thrombosis but showed a dAVF. Partial closure of the dAVF was achieved by embolisation and on subsequent follow-up there was evidence of clinical improvement.

Conclusions This case highlights the importance of the diagnostic workup of dementia, the most appropriate radiological investigations for diagnosing and characterising dAVF’s, as well as the potential recovery post treatment for a dAVF. The presence of thalamic microbleeds in our case is unique and should alert the clinician to consider the possibility of dAVF.