During an attack of TN, the sufferer will almost always remain still and refrain from speech or movement of the face, so as not to trigger further attacks of pain. The face may contort into a painful wince. Early descriptions of TN confused these sudden attacks with seizures, leading to the term tic doloureux or neuralgia epileptiforme. TN attacks rarely occur when the sufferer is asleep, but may be worsened or alleviated by leaning or lying in a specific position.
brief paroxysms of &quot;shock-like&quot; pain in 1 or more divisions of the trigeminal nerve (cranial nerve V). The pain most often occurs in &quot;machine-gun-like&quot; volleys, lasting a few seconds to a minute, and recurring frequently for weeks at a time. The pain can be so intense that it may precipitate facial spasms or wincing; hence the term &quot;tic douloureux.&quot; It typically occurs unilaterally, but in 4% of patients -- of whom, most have underlying multiple sclerosis -- it is bilateral. Patients may also experience a dull ache between the paroxysms of pain.
The pain is provoked by touching certain trigger zones or by other stimuli such as cold wind, talking, brushing the teeth, chewing, shaving or washing the face. Trigger zones most commonly are located on the cheek, lip, nose, or buccal mucosa
Pulsation of vessels upon the trigeminal nerve root do not visibly damage the nerve. However, irritation from repeated pulsations may lead to changes of nerve function, and delivery of abnormal signals to the trigeminal nerve nucleus. Over time, this is thought to cause hyperactivity of the trigeminal nerve nucleus, resulting in the generation of TN pain.
Atypical TN is characterized by a unilateral, prominent constant and severe aching, boring or burning pain superimposed upon otherwise typical TN symptoms.
D. Pre-Trigeminal Neuralgia Days to years before the first attack of TN pain, some sufferers experience odd sensations in the trigeminal distributions destined to become affected by TN. These odd sensations of pain, (such as a toothache) or discomfort (like &quot;pins and needles&quot;, parasthesia), G. Trigeminal Neuropathy or Post-Traumatic Trigeminal Neuralgia The pain of trigeminal neuropathy or post-traumatic TN is usually constant, aching or burning, but may be worsened by exposure to triggers such as wind and cold. Such deafferentation pain can start immediately or days to years following injury to the trigeminal nerve. In the most extreme form, called anesthesia dolorosa, there is continuous severe pain in areas of complete numbness.
Image: CT, MRI, MRA Try and error: carbamazepine
Block of the gasserian ganglion is performed with the patient in the supine position.6 Location of the foramen ovale is facilitated by the use of fluoroscopic guidance.When fluoroscopy is used, the C-armis angled so that the axis of the x-raybeamis aligned to reveal the foramen ovale (oblique and caudal angulation). Askin wheal of local anesthetic is raised 2–3 cmlateral to the corner of the mouth and a 22-gauge, 10-cm spinal needle is advanced upward toward the mandibular condyle in a plane in line with the pupil (Figure 18–5). The surface of the greater wing of the sphenoid bone is typically contacted at a depth of 4 to 6 cm, and the needle is withdrawn and redirected in amore posterior direction until the foramen ovale is entered. Once the needle enters the foramen, it is advanced an additional 1–1.5 cm. As the foramen is entered, a paresthesia in the mandible is usually elicited. As the advancement continues, paresthesia in the maxilla and orbit are also typically reported. Injection volume of 1.0 mL is usually sufficient to produce dense analgesia. Paresthesia in the effected division is sought to guide needle placement prior to neurolysis.
Unexplained peripheral nerve pain
The most common site: head and neck
The most frequently diagnosed form:
trigeminal neuralgia (TN)trigeminal neuralgia (TN)
Tic douloureux (painful jerking)
Mean age: 50 y/o
Female predominance (male : female = 1:2 ~2:3)
Characteristics of trigeminal neuralgiaCharacteristics of trigeminal neuralgia
paroxysms of severe, lancinating,
electric shock-like bouts of pain
restricted to the distribution of the
Unilaterally (right side)
The mandibular (V3) and/or maxillary (V2)
branch or, rarely, the ophthalmic (V1) branch
Spontaneously attack or triggered by
trigger zone & movement of the face
Seconds to minutes
0.5~1.5 ml of 80~100%
Whole branch & smaller
peripheral nerve branches
External approach &
Exposed surgically and
direct application of a
3 cycles of 2 min. with a 5
min. thawing period in
Ganglion-level proceduresGanglion-level procedures vs.
Peripheral proceduresPeripheral procedures
Ganglion-level ablative procedures
Similar long-term success rate
Varying degrees of sensory loss
Balloon compression: least likely to impair
corneal sensation or to cause anesthesia
High recurrence rates
No benefit over ganglion-level procedures
Reserved for emergency use
Flow chart of the current practice of surgery for TN at UCLA.
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(a) Thermal lesion of trigeminal nerve.(a) Thermal lesion of trigeminal nerve. (b) Mislocation of the electrode.(b) Mislocation of the electrode.
(c) Expansion of thermal energy to neighboring neural structures.(c) Expansion of thermal energy to neighboring neural structures.