Short Unilateral Neuralgiform Headache Attacks (SUNHA): Workup and Management
Initial Diagnostic Workup
The essential first step is obtaining MRI brain imaging including the pituitary fossa to exclude secondary causes, particularly neurovascular compression and posterior fossa lesions. 1, 2, 3
Key Clinical Features to Confirm Diagnosis
Attack characteristics: Strictly unilateral pain in the trigeminal distribution (most commonly V1/V2), lasting seconds to several minutes (typically 1-600 seconds for individual stabs), occurring 2-600 times daily with no refractory period between attacks 1, 4
Pain quality: Sharp, stabbing, or electric shock-like, moderate to severe intensity 1, 4
Autonomic features: Must document presence of ipsilateral conjunctival injection and/or tearing (both present = SUNCT; only one or neither = SUNA), plus other features including nasal congestion, rhinorrhea, eyelid edema, facial sweating, or ear fullness 1, 2, 4
Triggering factors: Cutaneous stimuli trigger attacks in approximately 74% of SUNCT cases (light touch, washing face, chewing), with attacks occurring spontaneously as well 1, 4
Patient behavior: Unlike cluster headache patients who are agitated and restless, SUNHA patients may be agitated during attacks but this is less consistent (present in 58% of SUNCT cases) 4
Critical Differential Diagnoses to Exclude
Trigeminal neuralgia differs by having a refractory period between attacks (SUNHA typically has none), longer attack-free intervals, and less prominent autonomic features, though significant overlap exists and these may represent a continuum of the same disorder 1, 2, 5
Cluster headache is distinguished by longer attack duration (15-180 minutes versus seconds to minutes), lower attack frequency (1-8 daily versus up to 600 daily), and prominent restlessness during attacks 1, 6
Neuroimaging Protocol
MRI brain with contrast including pituitary fossa views is mandatory to identify neurovascular compression (particularly superior cerebellar artery loops compressing the trigeminal root), posterior fossa lesions, pituitary pathology, and other structural causes 1, 2, 3, 7
Approximately 15-20% of SUNHA cases are secondary to structural lesions including vascular malformations, posterior fossa tumors, or cavernous sinus pathology 2, 3
Acute Management
Abortive therapies are generally not useful because attacks are too short-lasting (seconds to minutes) to respond to acute medications. 2, 3
- The brief duration of individual attacks makes traditional acute treatments impractical, as medications cannot achieve therapeutic effect before the attack spontaneously resolves 2, 3
Preventive Medical Management
Lamotrigine is the most effective oral preventive treatment and should be first-line therapy. 1, 2, 3, 5
Lamotrigine Dosing Strategy
Start at low dose (25 mg daily) and titrate slowly upward over weeks to minimize risk of Stevens-Johnson syndrome 2, 3
Typical effective dose range: 100-400 mg daily in divided doses 2, 3
Clinical benefit may take 2-3 months to manifest, requiring adequate trial duration 2, 3
Transitional Therapy for Severe Disabling Attacks
Intravenous lidocaine is the most efficacious transitional treatment during severe attack periods. 2, 3, 5
Administer IV lidocaine during worst periods to decrease attack intensity and frequency while waiting for preventive medications to take effect 3, 5
This provides bridge therapy until oral preventives achieve therapeutic benefit 3, 5
Alternative Medical Options
Other medications tried in open-label case reports with variable success include topiramate, gabapentin, and carbamazepine, but evidence quality is poor compared to lamotrigine 2, 3
Surgical Management for Medically Refractory Cases
For patients failing medical management, microvascular decompression (MVD) of the trigeminal nerve should be considered when neurovascular compression is demonstrated on MRI. 2, 3, 5, 7
Surgical Options by Evidence Quality
Microvascular decompression: Most effective when vascular compression of trigeminal root is identified on imaging, with high response rates in open-label series and durable long-term outcomes (up to 2+ years symptom-free) 2, 3, 7
Occipital nerve stimulation: Effective alternative for medically intractable cases, with relatively high response rates in open-label series 2, 3
Hypothalamic/ventral tegmental area deep brain stimulation: Reserved for most refractory cases, showing efficacy in small open-label series 2, 3
Ablative procedures (trigeminal nerve or Gasserian ganglion): Less preferred due to risk of permanent sensory deficits and anesthesia dolorosa 2
Critical Clinical Pitfalls
Do not assume all brief neuralgiform attacks are trigeminal neuralgia—the presence of prominent autonomic symptoms distinguishes SUNHA and requires different management. 1, 2, 5
Do not overlook secondary causes—failure to obtain MRI imaging may miss treatable structural lesions including neurovascular compression amenable to surgical decompression. 2, 3, 7
Do not attempt acute abortive therapy as primary strategy—the ultra-short attack duration makes this approach futile; focus on preventive management. 2, 3
Recognize the nosological overlap—SUNHA, trigeminal neuralgia, and their variants may represent a continuum rather than distinct entities, requiring flexible diagnostic and therapeutic approaches. 2, 5