Ischaemic stroke after facial filler injection
A rare but documented complication in which embolised material reaches the intracranial circulation — and why it is a transfer, not a clinic-managed event.
Cerebral infarction after cosmetic filler injection is rare. It is also documented well enough in the case literature that it belongs in any honest account of injectable risk.
The route
The mechanism extends the one behind filler-induced blindness. Material entering a facial artery branch under pressure travels retrograde toward the anastomoses around the orbit. From the ophthalmic artery it can reach the internal carotid circulation and, from there, intracranial branches — the middle cerebral artery territory in particular.
Published cases describe sudden vision loss accompanied by neurological deficit: hemiparesis, dysarthria, facial weakness, altered consciousness, with infarction confirmed on imaging.
Where it has been reported
The same high-risk injection sites as ocular events — glabella, forehead, nose and periorbital region. Autologous fat is over-represented, plausibly because of the volumes and injection pressures involved, though hyaluronic acid cases are described too.
Recognition
Any neurological symptom during or shortly after facial injection: weakness on one side, speech disturbance, facial droop that is not explained by local anaesthesia, confusion, severe headache, or vision loss with any of these alongside it.
The distinction from a toxin-related weakness is timing. Toxin effects appear over days. Anything neurological appearing within minutes of an injection is vascular until proven otherwise.
What to do
This is a medical emergency requiring immediate transfer, and the recognition that matters most is recognising that it is not a clinic-managed event.
Hyaluronidase does not address an intracranial embolus. Time spent administering it while a patient has evolving neurological signs is time not spent getting them to a stroke service, where imaging and time-critical intervention are available. Local hyaluronidase to the facial territory remains appropriate for the cutaneous component, but it must not delay transfer.
What it implies for consent
The possibility of stroke belongs in the conversation for high-risk regions, uncomfortable as that is. A patient consenting to glabellar or nasal filler is consenting to a procedure with a documented — if very rare — association with permanent neurological injury, and describing the risk as “bruising and swelling” does not represent it accurately.
