Vasovagal Syncope After Neck Nerve Treatment: Case Report

A 41-year-old woman experienced a sudden, delayed loss of consciousness 20 hours after receiving a pulsed radiofrequency treatment for her chronic neck and headache pain. This case, documented by researchers Kurnia Hendra Wijaya and Buyung Hartiyo Laksono, describes a rare but serious delayed vasovagal syncope event following a common pain procedure, with direct implications for tinnitus and vertigo management.

## A Delayed and Uncommon Reaction to a Common Procedure

Pulsed radiofrequency (PRF) is a standard treatment for chronic cervical radicular pain and occipital neuralgia. It applies short bursts of radiofrequency energy near specific nerves. The goal is to modulate pain signals without destroying nerve tissue. The procedure is considered minimally invasive and safe, with most side-effects being mild and temporary, like local discomfort.

This case report, published in the Journal of Anesthesia and Clinical Research, details an exception. The patient had a complex history including chronic cervical radiculopathy from a herniated disc, tension-type headaches, cluster headaches, and notably, chronic spontaneous vertigo and tinnitus. She underwent bilateral PRF treatment on her lesser and greater occipital nerves and the C3 and C4 dorsal root ganglia. The procedure itself, done under light sedation with propofol and midazolam, was completed without any immediate issues.

The significant event began nearly a full day later. Approximately 20 hours post-procedure, the patient developed an acute decrease in consciousness. Her Glasgow Coma Scale score, a measure of consciousness level, dropped to a nadir of 12. Her heart rate profile was consistent with a vasovagal episode, a reflex that can cause fainting due to a sudden drop in heart rate and blood pressure. She experienced gradual spontaneous recovery over seven hours, returning to full consciousness (GCS 15) without any lasting neurological deficits.

## Tinnitus and Vertigo Improved Despite the Complication

A critical finding from this case was the effect on the patient’s auditory and vestibular symptoms. When researchers compared her pre- and post-procedural symptoms, they noted a clear improvement in her cervical paraesthesia (abnormal skin sensations), her chronic spontaneous vertigo, and her tinnitus. Her cluster-type headaches also improved.

This symptomatic relief is significant for the hearing health community. It suggests that neuromodulation of the upper cervical and occipital nerves, which are intricately linked to the trigeminocervical complex, can influence pathways involved in some forms of tinnitus and vertigo. This aligns with a neuroplasticity-based understanding of these conditions, where maladaptive neural pathways contribute to persistent symptoms. Modulating input in connected neural networks, as explored in articles on Tinnitus Management Strategies: A Neuroplasticity Review, can sometimes lead to positive changes.

## Pathophysiology: Connecting Nerve Stimulation to a Systemic Reflex

The researchers propose a physiological explanation for the delayed syncope. The PRF procedure stimulates the afferent nerves of the cervical dorsal root ganglia and occipital nerves. These nerves feed into the trigeminocervical complex, a major hub in the brainstem.

In a susceptible patient, this sustained afferent signaling is thought to have activated the Bezold–Jarisch reflex. This reflex originates in the heart; when certain cardiac sensory nerves are stimulated, they signal the brainstem to slow the heart rate and dilate blood vessels, leading to a drop in blood pressure and potentially fainting. The patient’s newly diagnosed hypertension might have been a contributing susceptibility factor. The 20-hour delay remains unusual but may relate to the prolonged neuromodulatory effects of PRF or the resolution of local anesthesia.

## Practical Implications for Patient Safety and Management

The primary practical implication of this case is for safety protocols. While PRF is low-risk, this report demonstrates that rare, delayed systemic reactions are possible. Wijaya and Laksono recommend several precautions:
* **Multimodal monitoring** during the procedure.
* **Careful titration of sedation** to avoid oversedation which can mask early warning signs.
* **Adequate patient hydration** before and after the procedure.
* **Structured post-procedural observation** for an extended period. They suggest that a 24-hour observation window with clear patient instructions on recognizing warning signs may be prudent.

For patients considering similar procedures for pain conditions that co-occur with tinnitus or hyperacusis, this case is double-edged. It shows a potential pathway for symptom relief, as seen in the patient’s improved tinnitus and vertigo. However, it also underscores the importance of a thorough pre-procedural evaluation by a specialist who understands these complex interactions. A comprehensive approach that includes counseling interventions and sound-based strategies, reviewed in our 2024 sound machine guide, remains a cornerstone of management.

This single case report, available via its DOI: 10.37275/jacr.v7i1.890, does not change the overall safety profile of pulsed radiofrequency. It acts as an important reminder that interventions affecting the cervical neural landscape can have unexpected systemic consequences, requiring vigilance and personalized patient care.