微創介入治療舒緩嚴重頭痛
摘要：
當藥物無法舒緩嚴重頭痛時，微創介入治療能精準針對引發痛楚的神經，提供安全及長效的止痛方案。
頭痛的介入治療
頭痛是常見且令人困擾的問題。雖然多數情況可透過藥物控制，但部分患者對藥物反應欠佳。遇到這些情況，醫生便會考慮採用介入治療。這是一種微創技術，止痛效果比藥物或針灸等保守治療更顯著，且創傷性遠低於傳統的開放式手術。
介入治療的原理
頭痛的痛源主要涉及供應面部的三叉神經（trigeminal nerve）及上頸椎的感覺神經，這些神經都是介入治療的主要目標。此外，除了感覺神經外，自律神經系統在某些特定頭痛，例如叢發性頭痛（cluster headache）的形成中亦扮演著關鍵角色。
介入治療的種類
醫生會根據引發痛楚的神經結構及病情，選擇最合適的治療方案。常見的介入方法包括：神經阻滯、脈衝射頻、高溫射頻神經消融、肉毒桿菌毒素注射，以及使用周邊神經刺激器等。
神經阻滯
神經阻滯是較為簡單的治療方法。醫生會在超聲波或 X 光導引下尋找目標神經的位置，並於神經周圍注射局部麻醉藥或類固醇。這個治療常用於舒緩緊張型頭痛或偏頭痛。主要針對的神經包括：枕大神經（greater occipital nerve）、枕小神經（lesser occipital nerve）、第三枕神經（third occipital nerve）、眶上神經（supraorbital nerve）及耳顳神經（auriculotemporal nerve）等。如果神經阻滯的療效不夠持久，醫生便會考慮進階的射頻治療。
脈衝射頻治療
過程與神經阻滯相似，但對精準度的要求更高。醫生在影像導引下將特製的細針引導至神經旁，並接上脈衝射頻儀器，利用電磁波刺激神經，從而降低它對痛楚的敏感度，達到長效舒緩。
高溫射頻神經消融
在某些特定情況下，醫生會利用射頻儀器產生高溫，把傳遞痛覺的神經纖維進行消融。這種方法能直接阻斷痛覺傳遞，從而發揮顯著的止痛效果。
肉毒桿菌毒素注射
除了局部麻醉藥或類固醇，醫生有時也會採用肉毒桿菌毒素來處理慢性頭痛。做法是將毒素注射在頭面及頸部多個特定位置，當供應面部的三叉神經吸收肉毒桿菌毒素後，感覺神經系統的敏感度便會降低，從而減少頭痛發作。
自律神經節治療
上述的神經阻滯或射頻技術，同樣可以應用在自主神經節上。部分罕見頭痛會涉及自律神經，或是出現交感神經維持性疼痛（sympathetically maintained pain）。在這些情況下，醫生會針對相關的神經節進行治療，兩個最常作為治療目標的結構包括蝶腭神經節（sphenopalatine ganglion）及星狀神經節（stellate ganglion）。
神經刺激器
對於極度頑固且對其他治療無效的頭痛，醫生會考慮植入微型的周邊神經刺激器。透過持續釋放微弱電流刺激神經，能有效干擾痛楚信號的傳遞，達到改善頭痛的理想效果。
Summary: When medications fail to relieve severe headaches, interventional treatments offer a safe and effective alternative. By precisely targeting the specific nerves responsible for the pain, these procedures can provide significant and long-lasting relief.
Interventional Treatments for Headaches
Headaches are a common and distressing problem. While most cases can be managed with medication, some patients do not respond well to pharmacological treatments. In such situations, a doctor may consider interventional treatments. This is a minimally invasive approach that offers better pain relief than conservative treatments like medication or acupuncture, and is far less invasive than traditional open surgery.
The Principle of Interventional Treatments
The source of headache pain mainly involves the trigeminal nerve, which supplies the face, and the sensory nerves in the upper cervical spine (neck). These nerves are the primary targets of interventional treatments. In addition to sensory nerves, the autonomic nervous system also plays a crucial role in the development of certain specific types of headaches, such as cluster headaches.
Types of Interventional Treatments
Doctors will select the most appropriate treatment plan based on the nerve structure causing the pain and the patient’s condition. Common interventional methods include nerve blocks, pulsed radiofrequency, thermal radiofrequency ablation, botulinum toxin injections, and peripheral nerve stimulators.
Nerve Blocks
A nerve block is a relatively straightforward procedure. Using ultrasound or X-ray guidance, the doctor locates the target nerve and injects a local anaesthetic or steroid around it. This treatment is commonly used to relieve tension-type headaches or migraines. The main target nerves include the greater occipital nerve, lesser occipital nerve, third occipital nerve, supraorbital nerve, and auriculotemporal nerve. If the effects of a nerve block are not long-lasting enough, the doctor may consider advanced radiofrequency treatments.
Pulsed Radiofrequency Treatment
The process is similar to a nerve block but requires even higher precision. Under imaging guidance, the doctor guides a specialised fine needle next to the nerve and connects it to a pulsed radiofrequency machine. This device uses electromagnetic waves to stimulate the nerve, lowering its sensitivity to pain and achieving long-lasting relief without damaging the nerve itself.
Thermal Radiofrequency Ablation
In certain specific situations, the doctor will use a radiofrequency machine to generate high temperatures to ablate (destroy) the nerve fibres that transmit pain. This method directly blocks the transmission of pain signals, resulting in highly effective pain relief.
Botulinum Toxin Injections
Besides local anaesthetics or steroids, doctors sometimes use botulinum toxin to treat chronic headaches. The procedure involves injecting the toxin into multiple specific sites across the head, face, and neck. Once the trigeminal nerve absorbs the botulinum toxin, the sensitivity of the sensory nervous system is reduced, thereby decreasing the frequency of headache attacks.
Autonomic Ganglion Treatments
The nerve blocks or radiofrequency techniques mentioned above can also be applied to autonomic ganglia (clusters of nerve cells). Some rare headaches involve the autonomic nervous system, or present as sympathetically maintained pain. In these cases, the doctor will target the relevant ganglion for treatment. Two of the most common targets are the sphenopalatine ganglion and the stellate ganglion.
Nerve Stimulators
For extremely stubborn headaches that do not respond to other treatments, a doctor may consider implanting a miniature peripheral nerve stimulator. By continuously releasing mild electrical currents to stimulate the nerves, it effectively interferes with the transmission of pain signals, achieving an ideal improvement in headache symptoms.
