三叉神经痛 (Trigeminal neuralgia)
Anatomic structure Cerebellopontine Angel (CPA) Cerebrospinal Fluid(CSF) Root Entry/Exit Zone(REZ) Cranial NerveⅤⅦⅧⅨⅩⅪⅫ 桥 - 小脑角 脑脊液 神经根出入脑干区 Trigeminal n. Facial n. & Ventibulocochlear n. Glossopharyngeal n. /Vagus n. /Accessory n. /Hypoglossal n. Vertebrobasilar Artery System 椎基底动脉系统 Basilar a. Superior cerebella a. (SCA) Anterior inferior cerebella a. (AICA) Vertebral a. Posterior inferior cerebella a. (PICA)
Anatomic structure
Semilunar ganglion
Definition 1958 年 Wartenberg 提出临床诊断标准 ( 五点 ) 1. Paroxysmal pains with free internals 阵发性的 有缓解期的疼痛 2. No objective clinical findings 无客观的临床发现 ( 炎症 肿瘤等 ) 3. No pathological findings at postmortem 尸检无神经病理性改变 4. Trigger zones 存在 扳机点 5. Pain restricted to the area of the trigeminal nerve 三叉神经分布区域内
Trigeminal neuralgia(tgn) Prevalence rate: 3.4~7.2/100,000 80% to dentists at first Diagnostic criteria for idiopathic TGN ---International Headache Society(1988) 1. Paroxysmal attacks of facial or frontal pain lasting for a few seconds to less than two minutes 2. At least four of the following five characteristics are needed: Distribution along one or more divisions of trigeminal n. Sudden,intense,sharp,superficial,stabbing,and burning pain quality Severe pain Evidence of trigger zones No symptom between attacks
Etiology symptomatic 脑干病变 : 延髓空洞症 炎症 肿瘤 多发性硬化 感觉根病变 ( 颅后窝 ): 桥小脑角肿瘤 / 瘤样病变 半月节病变 ( 颅中窝 ): 颅底肿瘤 / 瘤样病变 周围支病变 : 炎症 肿瘤
Tumor(2%~5%) meningioma arachnoid cyst acoustic neuroma arteriovenous malformation
Etioloy idiopathic 中枢病因学说 ( 癫痫学说 ): 三叉神经脊束核 丘脑 大脑皮层 周围病因学说局部刺激学说 ( 炎症 病毒 ) 周围病因学说 变态反应学说 病毒感染学说 家族遗传学说 局部压迫学说 硬脑膜 蛛网膜 骨嵴 / 骨孔 血管 血管神经压迫学说 (71%~93%)
Neurovascular compression(nvc)
Pathogenesis 解剖基础 ---- 脱髓鞘 (demyelination) + 伪突触 (false synaps) 1. 短路 (short circuit) 2. 双向传导 (bi-conduction) 3. 速度减慢中枢总和 (central summarization) 4. 其它感觉递质 ( 触压觉 温度觉 肌梭本体感觉 ) 异常突触痛觉递质中枢痛觉 (transmitter) 中枢神经元病变 (neuron lesion)
Mean FREQ Epidemiology( 流行病学调查 ) 1.incidence 国内 :47.8 人 /10 万人口国外 :62.6 人 /10 万人口 2.sex female(58%):male(42%) 20 10 8 16 18 15 8 3.age 2 0 <20a 20-30a 40a~70a(average 55a) (40s-18% 50s-29% 60s-28%) 4.family history 30-40a 40-50a 50-60a AGE 图 1-1 TGN 的年龄分布图 60-70a >70a 5%
Clinical features 1.pain sharp,shooting pain like lightning or an electric shock while some dull, burning, throbbing. 2. periodicity and duration pain last only a few minutes or even seconds with periods of complete freedom from pain attack on dull pain 58% have spontaneous remission of 6 mo after first attack 3. trigger zone and provoking factors 40%~50% common area: around nose and lip
4. sides involved right-61% left-36% both-3% 5.radiation Ⅰ,Ⅱ,Ⅲ Ⅲ 4.4% 25.0% Ⅱ,Ⅲ 36.8% Ⅱ Ⅰ,Ⅱ 32.3% 1.5% 图 1-2.TGN 受累分支构成百分比
Examination 1.division 2.motion masticatory m. atrophy 肌萎缩? muscle strength 肌力 3.feeling 触觉 痛觉 温度 中枢 / 周围 electrodiagnostic neurostimulator
4. 神经反射检查浅反射 ( 角膜反射 腭反射 ) 深反射 ( 眉间反射 ) 病理反射 ( 口轮匝肌反射 吸吮反射 下颌反射等 ) 其他 ( 瞳孔 肌张力等 ) 5. 影像学检查牙片 全景片 颅底 CT MRI
MRTA
Clinical feature of idiopathic TN Character of pain sharp,shooting Site distribution of trigemianl n. Radiation trigeminal area,unilateral Periodicity paroxysmal Duration with remission Severity extremely severe Provoking factors light tough Relieving factors anticonvulsant,local anaesthesia Associated factors trigger points, weigh loss
Pain behaviour in patiernts with TN Facial expressions Motor activity Body gestures Behaviour to reduce pain Functional limitations distortion,crying immobility guarded posture covering the face outdoors decreased socialization multiple medical options reluctance to talk inability to eat inability to brush teeth,shave or wash
Differential diagnosis of facial pain Conditions affecting trigeminal nerve Conditions not affecting trigeminal nerve Dental conditions Otolaryngological conditions Eye conditions Neoplasia Vascular conditions Idiopathic conditions Pre-trigeminal neuralgia Post-herpetic neuralgia Cluster headache Hemifacial spasm Glossopharyngeal neuralgia Dentinal/ Pulpal/periodontal causes Cracked tooth Temporomandibular disorders Salivary gland diseases Sinusitis Iritis/Optic neuritis/glaucoma Migraine Giant cell arteritis Atypical facial pain
Key diagnostic features : cluster headache Severe,stabbing, burning pain Unilateral and in distribution of Ⅴ Cyclic, predictable attack, often nightly Provoked by alcohol Eye redness, nasal stuffiness, facial flushing More prevalent in young men
Key diagnostic features :migraine Severe,throbbing, pulsating pain Unilateral but sides often change Attack of pain lasting several hours Patients identify provokinf factors Self-limiting Many accompanied by prodromal aura Nausea, vomiting,photophobia
Treatment Medical management(non-surgery) drug block acupuncture γ-knife/x-knife Surgical management peripheral level Gasserian Ganglion level posterior fossa level
Drugs Baclofen Carbamazepine(Tegretol) Dilatin Clonazepam Oxcarbazepine
Carbamazepine first step Highly specific in relieving TN 70-80% respond well art early stage 100mg/d, 100mg/3d increase, not more than 1000mg 100mg/3-7d decrease Side-effects(20%): hypersensitivity,ataxia( 共济失调 ),dizziness,vomiting, reduced WBC,folate deficiency( 叶酸缺乏 )
Block therapy Supraorbital foramen, Infraorbital foramen, inferior alveolar nerve, foramen avale, ganglion, ect Lido+ MgSO 4, alcohol, glycerol( 无水甘油 )doxorubicin( 阿霉素 ) 40% relief(2y), high recurrence rate Side-effects: edema, sensory loss, tissue necrosis
X-knife therapy of trigeminal ganglion Cor 3d Fiesta Sag 3d Fiesta Axi 3d Fiesta
X-knife therapy of trigeminal ganglion
Peripheral Surgery Neurectomy( 神经撕脱 ) Cryotherapy( 冷冻 ) Jawbone cavity removal( 骨腔刮治 ) Peripheral radiofrequcy thermocoagulation( 射频温控热凝术 ) Bone canal decompression( 骨管减压 )
neurectomy Supraorbital, Infraorbital, inferior alveolar nerve Removal of adequate length, even from skin or foramen Blockage of bone canal with nonresorbable material(bone wax) all recurred within 3y Complications: sensory loss
Bone canal decompression 86.7%
Surgery at level of gassarian ganglion radiofrequcy thermocoagulation,rft( 射频温控热凝术 ) Microcompression( 微囊加压术 ) 50~60%
RFT CT guided
advantages Safe for older patients Immediate relief of pain Relatively low recurrence rate Low mortality rate Few complications
Recurrence rate: <20% Complication: intracranial haematoma( 血肿 ) wrong puncture/puncture failure(7%) keratitis( 角膜炎 ) sensory loss(98%) motor weakness blind
Navigation of RFT
Posterior fossa surgery Microvascular decompression,mvd ( 微血管减压术 ) Sensory root rhizotomy ( 感觉根切断术 )
手术方法 切口线 骨窗 涤纶片 责任血管 三叉神经根
MVD
Advantages: preservation of nerve function 50%~60% (eyes) 85%~90% (microscope) 96%~97% (endoscope) Complication: mortality 0.2% intracranial haematoma meningitis( 脑膜炎 ) ataxia cranial nerve damage-diplopia 复视, hearing loss paralyse 面瘫
Clinical indications corresponding to diagnostic criteria ineffective or resistant or having severe side-effects to medical management recurrent from the other peripheral surgeries Having good general health and ability to tolerate MVD daring to accept MVD Radiological indications---magnetic resonance tomographic angiography, MRTA Exclude intracranial neoplasma Evaluate neurovascular compression
You have to select the right weapon for the right patient. Every person is different.