What is SUNCT/SUNA?

SUNCT ( short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing) is a rare primary headache syndrome that is characterized by severe, unilateral orbital or temporal pain that is stabbing or throbbing in quality. 

Diagnosis of SUNCT and SUNA

• SUNCT requires at least 20 attacks, lasting for 5–240 s
• There should be  ipsilateral conjunctival injection and lacrimation
• The pain of SUNCT/SUNA is unilateral and it may be located anywhere in the head. 
• Three basic patterns of SUNCT  can be seen 

                Single stabs, which are usually short-lived

                Groups of stabs

                A longer attack with many stabs between which the pain does not completely resolve, thus                   it  gives a “saw-tooth” phenomenon with attacks lasting many minutes.

• Characteristics feature that lead to a suspected diagnosis of SUNCT are the cutaneous (or other) triggerability of attacks, and there is lack of refractory period to triggering between attacks. 
• There is lack of a response to indomethacin.
• Apart from trigeminal sensory disturbance, the neurologic examination is normal in primary SUNCT.

Secondary (Symptomatic) SUNCT

Secondary SUNCT is seen with posterior fossa or pituitary lesions. All patients diagnosed with SUNCT/SUNA should be evaluated with pituitary function tests and a brain MRI 

Differential diagnosis

The diagnosis of SUNCT is sometimes confused with trigeminal neuralgia particularly in first-division TN . 

But in trigeminal neuralgia there are no cranial autonomic symptoms and there is clear refractory period to triggering 

Treatment  of SUNCT/SUNA

Abortive therapy

Treatment of acute attacks is not a useful concept in SUNCT/SUNA  because the attacks are of such short duration. Intravenous lidocaine, can arrests the symptoms, can be used in hospitalized patients with SUNCT.

Preventive therapy 

Long-term prevention is to minimize disability and hospitalization is the goal of treatment. 

Drugs for prevention

The drug that is most effective for prevention is lamotrigine, 200– 400 mg/d. 

Topiramate 

Gabapentin may also be effective.

Carbamazepine, 400–500 mg/day, can  offer modest benefit.

Surgical treatment of SUNCT/SUNA

Surgical approaches used for SUNCT/SUNA is microvascular decompression or destructive trigeminal procedures,they  are seldom useful and often they produce long-term complications. 

Greater occipital nerve injection offers limited benefit in some patients.