Post herpes zoster SUNCT like syndrome: Insights from two case reports

Abstract

Background

SUNCT like syndrome secondary to post herpes zoster infection has not been reported in literature.

Case

We are reporting two cases of SUNCT like syndrome secondary to post herpes zoster infection of the V1 distribution of the trigeminal nerve. Treatment with pregabalin and lamotrigine achieved complete symptomatic relief in both patients.

Conclusion

SUNCT like syndrome can occur after herpetic infection of the trigeminal nerve. Unlike primary SUNCT syndrome, post-herpetic SUNCT like syndrome seems to respond well to pharmacological treatment and has a good prognosis.

Introduction

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome is a primary headache disorder classified as a type of trigeminal autonomic cephalalgia (1). Secondary causes of SUNCT like syndrome have been reported (2). Here, we report two cases of SUNCT like syndrome secondary to post herpes zoster infection of the V1 distribution of the trigeminal nerve. To the best of our knowledge, there have been no such cases reported in literature.

Case 1

A 58-year-old man presented to us with severe pain and vesicular lesions in the right V1 distribution of the trigeminal nerve, and was diagnosed with herpes zoster infection. He was treated with acyclovir for seven days. The patient came back exactly one year later with episodes of excruciating pain in the right periorbital region, with redness and tearing of the eye on the same side, each episode lasting for 20 seconds. The tearing was exclusively during the pain attacks. He had had 4–5 attacks per hour for the past week. The attacks could be triggered by touching the affected area. He had headache attacks during the night that woke him up from sleep. These attacks were triggered when the affected forehead area came into contact with his bedding. On examination, there was no allodynia or hyperalgesia. The rest of the neurological and ophthalmological examination, including intra ocular pressure (IOP) measurement, was unremarkable. An MRI of the brain including sellar, suprasellar and paracellar regions was normal. He was diagnosed with SUNCT like syndrome and treated with pregabalin and lamotrigine at a dose of 75 mg twice a day and 25 mg at night. He became pain free two weeks after treatment. After three months of treatment, the medicines were tapered and stopped. The patient is pain free at five year follow up.

Case 2

A 60-year-old man presented with complaints of episodes of transient shooting pains around the left orbit, with redness, tearing and mild ptosis of the same side eye. The pain was severe, with a Visual Analog Scale of 10 on 10. He also had nocturnal attacks that woke him from sleep. He had been symptomatic for the past week, with a frequency of five attacks per hour lasting from 10 to 60 seconds. He had a history of left V1 distribution herpes zoster infection one month previously. However, the patient did not provide this information during the initial history taking. On examination, he was found to have healed herpetic rashes along the left V1 distribution. On retaking his history, he revealed that he had had a vesicular eruption on the left forehead that had healed spontaneously. Exactly a month later, he was diagnosed with SUNCT like syndrome affecting the same distribution as the herpes zoster infection. His systemic, neurological and detailed ophthalmological examinations, including IOP monitoring, were within normal limits. An MRI of the brain with contrast including sellar, suprasellar and parasellar regions to rule out secondary causes was normal. He was treated with 75 mg of pregabalin twice a day. Within 48 hours of starting treatment, the frequency of attacks reduced to 3–4 per day, and by 72 hours it had reduced to one attack per day. The patient was pain free at discharge and at three months’ follow up.

Discussion

SUNCT is a rare trigeminal autonomic cephalalgia characterised by attacks of moderate or severe, strictly unilateral neuralgiform paroxysmal orbital, supraorbital or temporal and/or other trigeminal distribution stabbing pain lasting for 1–600 seconds, accompanied by ipsilateral cranial autonomic features such as lacrimation and conjunctival injection (1). Although SUNCT is classified as a primary headache disorder, secondary causes have been increasingly reported, mostly involving the posterior fossa, pituitary gland and viral meningitis (2). Here, we have described two cases of herpes zoster infection of the V1 distribution of the trigeminal nerve that presented with SUNCT like syndrome after a period of one year and one month, respectively, contrary to pure post herpetic neuralgia, which is an ongoing persistent pain that lasts beyond three months after healing of the rash (3).

Post herpetic SUNCT like syndrome can be differentiated from post herpetic neuralgia by the presence of prominent autonomic symptoms such as conjunctival injection, watering and redness, unlike the latter, where the symptoms may be mild and not of much clinical significance. Also, patients with post herpetic neuralgia have itching and allodynia/hyperalgesia, which is characteristically absent in patients with post herpetic SUNCT like syndrome (1) (ICHD 13.1.2.2).

Unlike classical SUNCT, post herpetic SUNCT like syndrome seems to have a very good prognosis and does respond well to pharmacological treatment. It is interesting to note that the history of herpes zoster infection was not revealed by case 2 at presentation. This makes it worthwhile asking about a history of herpes zoster infection in every patient presenting with SUNCT syndrome.

The proposed pathophysiology of SUNCT is concomitant activation of the trigeminal autonomic reflex and trigeminal cervical complex, which likely accounts for the autonomic symptoms and pain (4). Both central and peripheral mechanisms may be responsible for the development of post herpetic SUNCT like syndrome. The infection of the trigeminal nerve by the herpes zoster virus may result in damage to afferent nociceptive C fibres, resulting in synaptic reorganisation at the level dorsal horn lamina II. Central terminals of Aβ fibres normally projecting into dorsal horn laminae III/IV could sprout into lamina II, forming functional new synapses, and resulting in alteration and amplification in various pain-signaling pathways. This may also cause spontaneous activity in deafferented central neurons and abnormal reorganisation of central connections, leading to aberrant activation of the trigeminal cervical complex and trigeminal autonomic reflex (5,6).

Informed consent

Both patients consented for their cases to be used for the purpose of publication.

Article highlights

SUNCT like syndrome can occur post herpetic zoster infection of the V1 trigeminal nerve.

Unlike classical primary SUNCT syndrome, post herpetic SUNCT like syndrome seems to have a good prognosis and does respond well to pharmacological treatment.