Microendoscopic stereotactic-guided percutaneous radiofrequency trigeminal nucleotractotomy.

OBJECT: Over the past few decades, various authors have performed open or stereotactic trigeminal nucleotractotomy for the treatment of neuropathic facial pain resistant to medical treatment. Stereotactic procedures can be performed percutaneously under local anesthesia, allowing intraoperative neurological examination as a method for target refinement. However, blind percutaneous procedures in the region of the atlantooccipital transition carry a considerably high risk of vascular injuries that may bring prohibitive neurological deficit or even death. To avoid such complications, the authors present the first clinical use of microendoscopy to assist percutaneous radiofrequency trigeminal nucleotractotomy. The aim of this article is to demonstrate intradural microendoscopic visualization of the medulla oblongata through an atlantooccipital percutaneous approach. METHODS: The authors present a case of severe postherpetic facial neuralgia in a patient who underwent the procedure and had satisfactory results. Stereotactic computational image planning for targeting the spinal trigeminal tract and nucleus in the posterolateral medulla was performed, allowing for an accurate percutaneous approach. Immediately before radiofrequency electrode insertion, a fine endoscope was introduced to visualize the structures in the cisterna magna. RESULTS: Microendoscopic visualization offered clear identification of the pial surface of the medulla oblongata and its blood vessels, the arachnoid membrane, cranial nerve rootlets and their entry zone, and larger vessels such as the vertebral arteries and the branches of the posterior inferior cerebellar artery. CONCLUSIONS: The initial application of this technique suggests that percutaneous microendoscopy may be useful for particular manipulation of the medulla oblongata, increasing the safety of the procedure and likely improving its effectiveness.

A lesão do trato de Lissauer e do corno posterior da medula espinal e a estimulação do sistema nervoso central para o tratamento da neuralgia pós-herpética / DREZ lesions and electrical stimulation of the central nervous system fortreatment of post-herpetic pain

Dor é uma complicação freqüente em doentes que apresentam erupção pelo vírus do herpes zóster. Os autores descrevem os resultados do tratamento operatório de 22 doentes com neuralgia pós-herpética. Sete doentes foram tratados pela técnica de lesão do trato de Lissauer(TL) e do corno posterior da medula espinal (CPME), sete pela técnica de estimulação elétrica da medula espinal, dois doentes por ambos os procedimentos e seis pela técnica de nucleotratotomia trigeminal estereotáxica. Foi observada significativa melhora imediata em 66,7%dos doentes com a técnica de estimulação medular, sendo mantida em 44,4% dos doentes a longo prazo. Ocorreu significativa melhora imediata em 50% dos doentes tratados pela nucleotratotomia trigeminal. A longo prazo, 33,3% dos doentes foram beneficiados. Foi observada melhora significativa imediata em 88,9% dos doentes tratados pela técnica da lesão do TL e do CPME. A longo prazo, a melhora foi observada em 66,6% dos casos. Síndrome cordonal posterior temporária ocorreu em dois doentes tratados pela nucleotratotomia trigeminal. Ela foi permanente em dois doentes tratados por essa técnica e em quatro pela lesão do TL e do CPME. Dos doentes tratados pela lesão do TL e do CPME ocorreu discreta hemiparesia permanente em quatro e um faleceu de embolia pulmonar durante o oitavo dia de pós-operatório. Concluiu-se que a lesão do trato de TL e do CPME e a estimulação elétrica da medula espinal proporcionaramresultados similares a longo prazo (p > 0,05). A técnica de estimulação, entretanto, é mais segura.

Post-herpetic pain is a very common and incapacitating disease. The authors analyse the effectiveness of the technique of dorsal root entry zone (DREZ) lesions, stereotaxic trigeminal nucleotractotomy (TNT) and dorsal column stimulation (DCS) for treatment of post-herpetic neuralgia. Twenty two patients were treated. Seven underwent DREZ; 7, DCS; 2 underwent both DREZ and DCS and 6, TNT. Immediate improvement (for 3 to 60 months ? median 12 months) of the symptoms occurred in 88.9% of the patients treated by DREZ. After a long term follow up period satisfactory results were observed in 66.7% of these patients. TNT resulted in significant immediate improvent of 50.0% of the patients and a long term (3 to 120 months ? median 8.5 (months) improvement of 33.3% of the cases. The DCS resulted in immediate improvement of pain in 66.4% of the patients. During a long term follow up period (6 to 18 months ? median 12 (months), 44.4% of the patients were better.The complication rate was higher among DREZ and TNT patients. It was concluded that the results of DREZ, TNT and DCS are similar (p > 0.05). However, DCS is safer, specially in cases of post-herpetic neuralgia affecting intercostal roots.