Generator sites of early scalp potentials evoked from the three trigeminal branches

1998 ◽  
Vol 88 (4) ◽  
pp. 718-725 ◽  
Author(s):  
Massimo Leandri
Keyword(s):  
Direct Evidence ◽  
Foramen Ovale ◽  
Superior Orbital Fissure ◽  
Entry Zone ◽  
Content Type ◽  
Maxillary Nerve ◽  
Root Entry Zone ◽  
Foramen Rotundum ◽  
Fine Print ◽  
Stimulation Of

Object. The aim of this study was to seek evidence about the generators of the first three components of the scalp's early trigeminal evoked potentials (TEPs) obtained by stimulation of the supraorbital (SW1, SW2, and SW3), infraorbital (W1, W2, and W3) and mental (MW1, MW2, and MW3) nerves. Methods. Simultaneous scalp and depth recordings were measured during surgical procedures in which thermorhizotomy and microvascular decompression were performed. Conclusions. Direct evidence was found that the origin of MW1 lies in the mandibular nerve at the foramen ovale, whereas the origin of W1 in the maxillary nerve at the foramen rotundum and the origin of SW1 in the ophthalmic nerve at the superior orbital fissure could only be inferred. The generators of SW2, W2, and MW2 were found to be on the nerve root at a distance of 10 mm from the pons. Calculations based on conduction velocity suggested that the generators of SW3, W3, and MW3 were inside the brainstem, at distances between 16 mm and 20 mm from the root entry zone. Recordings obtained in eight patients with discrete surgical lesions of the trigeminal pathway confirmed the sites of origin of the early components and further proved that only the fastest group of fibers is responsible for scalp responses.

Dorsal root entry zone lesions to control central pain in paraplegics

1981 ◽  
Vol 55 (3) ◽  
pp. 414-419 ◽  
Author(s):  
Blaine S. Nashold ◽  
Elizabeth Bullitt
Keyword(s):  
Dorsal Root ◽  
Central Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Cord Injury ◽  
Fine Print

✓ Thirteen patients with intractable long-term pain following spinal cord injury and paraplegia were treated with dorsal root entry zone lesions placed at the level just above the transection. Pain relief of 50% or more was achieved in 11 of the 13 patients, with follow-up periods ranging from 5 to 38 months. A previous report showed that central pain from brachial plexus avulsion could be relieved by dorsal root entry zone lesions, and this technique has been extended to the central pain phenomena associated with spinal trauma and paraplegia.

Diagnostic relevance of trigeminal evoked potentials following infraorbital nerve stimulation

1991 ◽  
Vol 75 (2) ◽  
pp. 244-250 ◽  
Author(s):  
Massimo Leandri ◽  
Emilio Favale
Keyword(s):  
Trigeminal Neuralgia ◽  
Infraorbital Nerve ◽  
Entry Zone ◽  
Content Type ◽  
Maxillary Nerve ◽  
Root Entry Zone ◽  
Idiopathic Trigeminal Neuralgia ◽  
Parasellar Region ◽  
Trigeminal Root ◽  
The Brain

✓ A new tool in neurophysiological exploration of the trigeminal nerve has recently been introduced. It has been demonstrated that stimulation of the infraorbital nerve trunk gives rise to very reliable scalp responses reflecting the activity of the afferent pathway between the maxillary nerve and the brain stem. The authors demonstrate that alterations of such trigeminal evoked responses fit with documented pathological processes at various locations along the trigeminal pathway (maxillary sinus, parasellar region, and within the brainstem parenchyma). They report the findings in 68 patients suffering from “idiopathic” trigeminal neuralgia. Alterations of the response were detected in 33 cases, suggesting that some damage of the nerve had taken place either at the root entry zone into the pons (23 cases) or slightly distal to it (10 cases). Such results support the hypothesis that trigeminal neuralgia may be due to a compression of the trigeminal root at the pons entry zone.

Long-term outcome after operation for trigeminal neuralgia in patients with posterior fossa tumors

1996 ◽  
Vol 84 (5) ◽  
pp. 818-825 ◽  
Author(s):  
Fred G. Barker ◽  
Peter J. Jannetta ◽  
Ramesh P. Babu ◽  
Spiros Pomonis ◽  
David J. Bissonette ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Posterior Fossa ◽  
Trigeminal Nerve ◽  
Posterior Fossa Tumors ◽  
Duration Of Symptoms ◽  
Long Term Outcome ◽  
Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Fine Print

✓ During a 20-year period, 26 patients with typical symptoms of trigeminal neuralgia were found to have posterior fossa tumors at operation. These cases included 14 meningiomas, eight acoustic neurinomas, two epidermoid tumors, one angiolipoma, and one ependymoma. The median patient age was 60 years and 69% of the patients were women. Sixty-five percent of the symptoms were left sided. The median preoperative duration of symptoms was 5 years. The distribution of pain among the three divisions of the trigeminal nerve was similar to that found in patients with trigeminal neuralgia who did not have tumors; however, more divisions tended to be involved in the tumor patients. The mean postoperative follow-up period was 9 years. At operation, the root entry zone of the trigeminal nerve was examined for vascular cross-compression in 21 patients. Vessels compressing the nerve at the root entry zone were observed in all patients examined. Postoperative pain relief was frequent and long lasting. Using Kaplan—Meier methods the authors estimated excellent relief in 81% of the patients 10 years postoperatively, with partial relief in an additional 4%.

Microvascular relations of the trigeminal nerve

1980 ◽  
Vol 52 (3) ◽  
pp. 381-386 ◽  
Author(s):  
Stephen J. Haines ◽  
Peter J. Jannetta ◽  
David S. Zorub
Keyword(s):  
Trigeminal Neuralgia ◽  
Trigeminal Nerve ◽  
Facial Pain ◽  
Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Venous Compression ◽  
Trigeminal Nerve Root ◽  
Trigeminal Nerves ◽  
Fine Print

✓ The vascular relationships of the trigeminal nerve root entry zone were examined bilaterally in 20 cadavers of individuals known to be free of facial pain. Fourteen of 40 nerves made contact with an artery, but only four of these showed evidence of compression or distortion of the nerve. In addition, the vascular relationships of 40 trigeminal nerves exposed surgically for treatment of trigeminal neuralgia were studied, and 31 nerves showed compression by adjacent arteries. Venous compression was seen in four of the cadaver nerves and in eight nerves from patients with trigeminal neuralgia. These data support the hypothesis that arterial compression of the trigeminal nerve is associated with trigeminal neuralgia.

Choristoma of the intracranial maxillary nerve in a child

1994 ◽  
Vol 81 (5) ◽  
pp. 788-791 ◽  
Author(s):  
Gabriel Lena ◽  
Thierry Dufour ◽  
Danielle Gambarelli ◽  
Brigitte Chabrol ◽  
Josette Mancini
Keyword(s):  
Resonance Imaging ◽  
Total Removal ◽  
Total Resection ◽  
Anterior Portion ◽  
Content Type ◽  
Maxillary Nerve ◽  
History Of ◽  
Foramen Rotundum ◽  
Extradural Approach ◽  
Fine Print

This report describes what the authors believe to be the first reported case of choristoma of the intracranial maxillary nerve. This 12-year-old girl presented with a 5-year history of severe isolated left-sided trigeminal neuralgia. Computerized tomography and magnetic resonance imaging revealed a mass below the anterior portion of the left cavernous sinus, enlarging the foramen rotundum. Total resection was achieved via a pterional extradural approach. Histological examination revealed a choristoma composed of smooth-muscle fibers. The histogenesis of these tumors when they develop in a nerve remains unclear. They may represent abnormal migration or proliferation of neuroectodermal tissue in or close to a peripheral nerve. Total removal of these tumors should be attempted at initial diagnosis.

Dorsal root entry zone lesions for intractable pain after trauma to the conus medullaris and cauda equina

1995 ◽  
Vol 82 (1) ◽  
pp. 28-34 ◽  
Author(s):  
John H. Sampson ◽  
Robert E. Cashman ◽  
Blaine S. Nashold ◽  
Allan H. Friedman
Keyword(s):  
Dorsal Root ◽  
Cauda Equina ◽  
Conus Medullaris ◽  
Intractable Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Relieve Pain ◽  
Fine Print

✓ This review was undertaken to determine the efficacy of using dorsal root entry zone (DREZ) lesions to treat intractable pain caused by trauma to the conus medullaris and cauda equina. Traumatic lesions of this area are unique in that both the spinal cord and the peripheral nerve roots are injured. Although DREZ lesions have been shown to relieve pain of spinal cord origin in many patients, they have been shown not to relieve pain of peripheral nerve origin. Therefore, 39 patients with trauma to the conus medullaris and cauda equina who underwent DREZ lesioning for intractable pain were reviewed retrospectively. The results of this review demonstrate the efficacy of DREZ lesions in these patients. At a mean follow-up period of 3.0 years, 54% of patients were pain-free without medications, and 20% required only nonnarcotic analgesic drugs for pain that no longer interfered with their daily activities. Better outcomes were noted in patients with an incomplete neurological deficit, with pain having an “electrical” character, and with injuries due to blunt trauma. Operative complications included weakness (four patients), bladder or sexual dysfunction (three), cerebrospinal fluid leak (two), and wound infection (two), but overall, 79.5% of patients (31 of 39) were without serious complications. Complications were limited to patients with prior tissue damage at the surgical exploration site and were most prevalent in patients who underwent bilateral DREZ lesions. In conclusion, this preliminary report suggests that DREZ lesions may be useful in combating intractable pain from traumatic injuries to the conus medullaris and cauda equina, with some risk to neurological function that may be acceptable in this group of patients.

Glossopharyngeal neuralgia

1977 ◽  
Vol 47 (3) ◽  
pp. 316-320 ◽  
Author(s):  
Ranjit K. Laha ◽  
Peter J. Jannetta
Keyword(s):  
Posterior Inferior Cerebellar Artery ◽  
Cranial Nerves ◽  
Glossopharyngeal Neuralgia ◽  
Vascular Compression ◽  
Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Cerebellar Artery ◽  
Sporadic Cases ◽  
Fine Print

✓ Various factors have been considered in the etiology and pathogenesis of glossopharyngeal neuralgia. Vascular compression of the involved cranial nerves has been demonstrated in sporadic cases. In this series of six patients, it was noted with the aid of the operating microscope that the ninth and tenth cranial nerves were compressed by a tortuous vertebral artery or posterior inferior cerebellar artery at the nerve root entry zone in five cases. In selected patients, microvascular decompression without section of the nerves may result in a cure.

Somatosensory function following dorsal root entry zone lesions in patients with neurogenic pain or spasticity

1991 ◽  
Vol 74 (6) ◽  
pp. 916-932 ◽  
Author(s):  
Daniel Jeanmonod ◽  
Marc Sindou
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Dorsal Root ◽  
Neurogenic Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Somatosensory Function ◽  
Fine Print

✓ The goal of this study was to assess the effects of the dorsal root entry zone (DREZ) lesioning procedure, microsurgical DREZ-otomy (MDT), on spinal cord somatosensory function based on peri- and intraoperative clinical and electrophysiological data. The study was performed prospectively on a series of 20 patients suffering from either chronic neurogenic pain or spasticity. Physiological observations were made of the intraoperative evoked electrospinographic recordings as collected from the surface of the spinal cord. The MDT procedure produced analgesia or severe hypalgesia, moderate hypesthesia, and only slight deficits in proprioception and cutaneous spatial discrimination on the body segments operated on. These clinical data correlated well with evoked electrospinographic recordings, which showed a moderate effect of MDT on presynaptic compound action potentials recorded from the spinal cord (N11 and N21), a partial or even reversible effect on the cortical postcentral N20 wave, a more marked effect on the postsynaptic dorsal horn waves N13 and N24 related to large primary afferent fibers, and a disappearance of dorsal horn waves related to finer afferents (N2 and possibly N3). These data provide evidence for an acceptably selective action of MDT on spinal cord nociceptive mechanisms, and for a partial, often slight, involvement of the other somatosensory domains. The presence of abnormal evoked electrospinographic waves is discussed in relation to the mechanisms of neurogenic pain and spasticity. The hypothesis of a “retuning” of the dorsal horn as the mode of action of MDT is presented.

Gamma knife radiosurgery using 90 Gy for trigeminal neuralgia

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 152-154 ◽  
Author(s):  
Bradley Nicol ◽  
William F. Regine ◽  
Claire Courtney ◽  
Ali Meigooni ◽  
Michael Sanders ◽  
...  
Keyword(s):  
Trigeminal Neuralgia ◽  
Gamma Knife ◽  
Gamma Knife Radiosurgery ◽  
Complete Relief ◽  
Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Good Pain Control ◽  
Fine Print

Object. The purpose of this paper was to assess the treatment of trigeminal neuralgia (TN) with the higher than normal dose of 90 Gy. Methods. Forty-two patients with typical TN were treated over a 3-year period with gamma knife radiosurgery. Every patient received a maximum dose of 90 Gy in a single 4-mm isocenter targeted to the root entry zone of the trigeminal nerve. Thirty of 42 patients had undergone no prior treatments. The median follow-up period was 14 months (range 2–30 months). Thirty-one patients (73.8%) achieved complete relief of pain. Nine patients (21.4%) obtained good pain control. Complications were limited to increased facial paresthesia in seven patients (16.7%) and dysgeusia in four patients (9.5%). Conclusions. The authors conclude that the use of 90 Gy is a safe and effective dose for the treatment of TN.

Dorsal root entry zone microcoagulation for spinal cord injury—related central pain: operative intramedullary electrophysiological guidance and clinical outcome

2002 ◽  
Vol 97 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Scott Falci ◽  
Lavar Best ◽  
Rick Bayles ◽  
Dan Lammertse ◽  
Charlotte Starnes
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Central Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Cord Injury ◽  
Electrical Data ◽  
Fine Print

Object. Surgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically resulted in modest outcomes. A review of the literature indicates that fair to good relief of pain is achieved in approximately 50% of patients when an empirical procedure is performed. This study was undertaken to determine if intramedullary electrical guidance in DREZ lesioning could improve outcomes in patients with SCI-induced central pain. Additionally, electrical data were used to determine if the spinal cord could be somatotopically mapped with regard to this pain of central origin. Methods. Forty-one patients with traumatic SCI and intractable central pain underwent DREZ lesioning in which intramedullary electrical guidance was conducted. In nine patients, recording of DREZ-related spontaneous electrical hyperactivity guided the lesioning process. In 32 patients, recording of DREZ-induced evoked electrical hyperactivity during transcutaneous C-fiber stimulation (TCS) additionally guided lesioning. The follow-up period ranged from 1 to 7 years. The analyzed electrical data allowed for somatotopic mapping of the spinal cord. Conclusions. Intramedullary electrical guidance of DREZ lesioning substantially improves pain outcomes in patients with traumatic SCI—induced central pain, compared with an empiric technique. The best outcome occurs when DREZ-related spontaneous electrical hyperactivity and evoked hyperactivity during TCS are both used to guide the DREZ lesioning procedure. With such guidance, 100% relief of pain was achieved in 84% of patients and 50 to 100% relief of pain in 88%. Somatotopic mapping of the electrical data led to a proposed pain mechanism for below-level pain, implicating the sympathetic nervous system.

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