Trigeminal neuralgia caused by compression of trigeminal nerve by pontine vein.

A case of trigeminal neuralgia which was apparently caused by compression of the trigeminal nerve by a pontine vein is presented. Complete relief followed the coagulation and dissection of the vein.     

Trigeminal neuralgia caused by a fibrous ring around the nerve

Trigeminal neuralgia is usually caused by compression of the nerve by vessels or a tumor. The authors report a case of trigeminal neuralgia not caused by vessel/tumor compression but by a constricting fibrous band around the trigeminal nerve. A 26-year-old man presented with typical trigeminal neuralgia. Although a gradient echo MR imaging demonstrated no offending vessel or a tumor, the patient agreed to undergo exploratory surgery. Intraoperatively, there were no vessels that could be the cause of the neuralgia; instead, the trigeminal nerve was constricted near the root entry zone. After the fiber was cautiously cut, the nerve expanded slightly. The neuralgia resolved without any neurological deficit, and the postoperative course was uneventful. A fibrous band around the trigeminal nerve can cause trigeminal neuralgia. When the symptom is typical and gradient echo MR imaging shows constriction of the trigeminal nerve, surgery is recommended to release the constricted the trigeminal nerve.     

Trigeminal neuralgia with the offending artery transfixing the trigeminal nerve: a case report

We report a rare case of a patient manifesting trigeminal neuralgia with the offending artery transfixing the trigeminal nerve. A 67-year-old woman was admitted with typical episodes of trigeminal neuralgia on the right side. Magnetic resonance angiograms revealed the right superior cerebellar artery (SCA) compressing the nerve. Through a retromastoid suboccipital craniotomy on the right side, the right SCA was found to compress the root entry zone (REZ) and then penetrate the portio major of the trigeminal nerve. The nerve was dissected parallel to the axis, 7 mm distally from the transfixing point to facilitate transposition of the SCA. In addition to anchoring the distal portion of the SCA to the tentrium, a prosthesis was interposed between the proximal portion and the pons to secure the decompression. The pain was completely relieved immediately after operation with no neurological deficit. Procedures, such as the longitudinal rhizotomy employed in this case, must be carried out for microcompression, in response to individual anatomical variations in neurovascular structures.     

Trigeminal neuralgia: compression of the trigeminal nerve by an elongated and dilated basilar artery.

A patient with trigeminal neuralgia caused by direct compression by an elongated basilar artery of the 5th nerve at the zone of entry of its sensory root into the pons is presented. Rhizotomy of the portio major is a treatment of choice in such a case instead of simple microsurgical decompression. The elongated basilar artery is very firm and not readily movable with manipulation.     

The retrogasserian zone versus dorsal root entry zone: comparison of two targeting techniques of gamma knife radiosurgery for trigeminal neuralgia

Background

We performed a comparative study of the retrogasserian zone (RGZ) with the dorsal root entry zone (DREZ) target to determine effective gamma knife radiosurgery (GKRS) technique in patients with medically refractory trigeminal neuralgia (TN).

Methods

We retrospectively reviewed the records of 39 patients with refractory TN undergoing GKRS between April 2005 and October 2008. Until October 2007, DREZ was used as the primary target point. Since November 2007, RGZ has been targeted, located anterior to DREZ. The pain outcome of patient, pain recurrence, and treatment-related complications were evaluated.

Findings

Using the Barrow Neurologic Index (BNI) pain score, 15 (93.8%) RGZ and 20 (87.0%) DREZ cases achieved treatment success (BNI pain score I–IIIb) (p?=?0.631). Seven (43.8%) RGZ and four (17.4%) DREZ patients reported complete pain relief without medications (BNI pain score I). The time to a response after the GKRS was significantly shorter in the RGZ group (mean 4.1 weeks) than in the DREZ group (mean 6.4 weeks) (p?=?0.044). The total complication rate (25.0%) in the RGZ group was similar to the DREZ group (26.1%); however, frequency of bothersome facial numbness and dry eye syndrome was lower in the RGZ group (0%, 0%) compared to the DREZ group (13.1%, 8.7%) (p?=?0.255 and 0.503).

Conclusions

The RGZ targeting technique in the GKRS for TN had a better treatment success, with fewer bothersome complications compared to the DREZ target.     

Electrophysiological mapping of the trigeminal nerve root during microvascular decompression for trigeminal neuralgia

A method for intraoperative electrophysiological mapping of the intracranial root of the trigeminal nerve was studied in five patients with trigeminal neuralgia. During surgery, the trigeminal nerve root was stimulated centrally with a bipolar electrode, and antidromic responses were recorded peripherally from three branches of the trigeminal nerve in the face. In all patients, the fibers of the individual subdivisions of the trigeminal nerve root were successfully localized based on the peripheral sites of antidromic response. This neural mapping was used during microvascular decompression in four patients and during a rhizotomy procedure in one patient. As a result of mapping, the fibers of the trigeminal division subserving the pain were clearly confirmed to be compressed by the artery in all four patients who were undergoing microvascular decompression. Likewise, the antidromic responses precisely identified the first division of the trigeminal nerve, which should be preserved to avoid postoperative corneal ulcers in patients undergoing rhizotomy. Based on these findings, it was concluded that this technique enables surgeons to precisely identify which fibers of the trigeminal nerve root should be decompressed or divided during surgery for trigeminal neuralgia.     

Trigeminal neuralgia. Percutaneous thermocoagulation of the trigeminal nerve (author's transl)

200 cases of percutaneous thermocoagulation of the trigeminal nerve were studied in order to determine if the position of the thermolesion in the various parts of the trigeminal system modified the quality of the results and the frequency of post-operative complications. An anatomo-radiological study allowed the precise localisation in the sagittal plane of the position of the different parts of the trigeminal ganglion with respect to the neighbouring bony features. The quality of the results and the frequency of complications were studied according to the level of the thermolesion (ganglion, triangular plexus, posterior sensory root). This study permitted the observation that the more posterior the thermolesion, the less frequent the complication, and this confirmed results obtained in earlier procedures, c.g. gasserian or retro-gasserian neurotomy. Post-operative hypoaesthesia extending beyond the painful area, was the major side-effect of the radicular position of the thermolesion. There follows a discussion of the criteria, which permit the recognition of the point of the electrode at the level of the posterior root: the flow of CSF, vasodilatation, and radiological localisations. Of these three criteria, only radiological demonstration (point of the needle posterior to the clivus and above the petrous temporal bone) seemed reliable.     

Dorsal root entry zone lesions for the treatment of post-herpetic neuralgia

Post-herpetic pain was treated in 12 patients using dorsal root entry zone ( DREZ ) lesions. All patients had failed to receive adequate pain relief from conservative therapy consisting of transcutaneous nerve stimulation, carbamazepine, and/or amitriptyline. Dorsal root entry zone lesions were made to include the involved dermatomes plus one-half of the dermatomes above and below the painful areas. Eight patients reported good pain relief with follow-up periods ranging from 6 to 21 months. A ninth patient obtained satisfactory pain relief, but the superior 1 cm of the original painful area was not included in the distribution of the DREZ lesions. Patients whose lesions were performed using a thermally controlled lesion probe suffered no significant postoperative neurological deficit. Dorsal root entry zone lesions appeared to be a satisfactory treatment for post-herpetic neuralgia in patients who have failed to respond to more conservative modes of therapy.     

Dorsal root entry zone lesions for the treatment of postherpetic neuralgia

These investigators attempted to diminish postherpetic neuralgia in 17 patients by making dorsal root entry zone (DREZ) lesions. They describe the clinical syndrome of pain after herpes zoster, the incidence of which increases with age, and discuss its pathology. They briefly review the medical and surgical treatment of postherpetic neuralgia. The results and complications of the DREZ procedure are reported.     

Trigeminal neuralgia associated with primitive trigeminal artery: report of two cases

Two cases of trigeminal neuralgia associated with the primitive trigeminal artery are reported. From 1981, the authors have treated 131 trigeminal neuralgia patients with microvascular decompression. Among them, we encountered two rare cases of trigeminal neuralgia associated with the primitive trigeminal artery (PTA) and its variant (PTAV). Case 1 is a 74-year-old woman who was admitted to our hospital due to pain of maxilla and mandible. We diagnosed her pain as trigeminal neuralgia. Preoperative angiogram showed the primitive trigeminal artery arising from the cavernous portion of the right internal carotid artery (ICA). She underwent a microvascular decompression operation. We found that her right trigeminal nerve was compressed by the right superior cerebellar artery (SCA) and the right anterior inferior cerebellar artery (AICA). We transferred the offending arteries, and her pain disappeared. Case 2 is a 48-year-old man who was admitted to our hospital due to severe mandibular pain. We diagnosed his pain as trigeminal neuralgia, and he underwent a microvascular decompression operation. His left trigeminal nerve was found compressed by the left SCA and the AICA, and the AICA was arising from the direction of Meckel's cave. His severe pain disappeared completely after operation. Postoperative angiogram of his left ICA showed an aberrant artery arising from the cavernous portion of the ICA, to the region of the left AICA. This aberrant artery is a variant of PTA (PTAV). PTA and PTAV, the so called persistent congenital arteries, are said to accompany aneurysms and other vascular lesions, and affect hemodynamic stress.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pain relief by stellate ganglion block in a case with trigeminal neuralgia caused by a cerebellopontine angle tumor

A 29-year-old woman with symptoms suggestive of trigeminal neuralgia is presented. Because of her age, an intracranial tumor was suspected, but images of a brain computerized tomography scan revealed nothing in particular. A magnetic resonance imaging was scheduled 2 weeks later. However, as the pain increased and occurred more frequently, the patient returned to the hospital 2 days later. After a stellate ganglion block with transient nausea and dizziness, the pain was noticeably relieved. Using magnetic resonance scanning, a tumor in the cerebellopontine angle was discovered, and at surgical resection was diagnosed as an epidermoid tumor. Stellate ganglion block may provide pain relief to some patients who are suspected to have symptomatic trigeminal neuralgia.     

Neuralgia of the intermediate nerve combined with trigeminal neuralgia: Case report

Summary An unusual case of a combination of trigeminal and intermediate nerve neuralgia is presented, caused by vascular compression of both of the nerve roots by different vessels. Because the neuralgia of the intermediate nerve could be cured by a vascular decompression operation, it is suggested to include it among the hyperactive dysfunction syndromes of cranial nerves caused by vascular compression at the root entry zone of the nerves. Therefore also for treatment of this neuralgia the non-destructive vascular decompression operation should be taken into consideration.     

Intrinsic arteriovenous malformation embedded in the trigeminal nerve of a patient with trigeminal neuralgia

A 66-year-old man presented with typical right trigeminal neuralgia. Neuroimaging showed a small arteriovenous malformation (AVM) in the right cerebellopontine angle. Suboccipital craniotomy verified that the AVM was almost completely embedded in the root entry zone of the trigeminal nerve and the nerve axis was tilted infero-posteriorly. The patient obtained complete pain relief without sequelae after surgery by transposition of the superior cerebellar artery and correction of the tilted nerve axis. The nidus of the unresected AVM was obliterated by gamma knife radiosurgery.