Non-communicating hydrosyringomyelia has been described in association with several types of spinal pathologies, but it has rarely been reported with demyelinative lesions. Therefore, we report a 39-year-old male patient with a history of peripheral facial palsy secondary to a cranial herpes zoster infection in 1996. He subsequently developed chronic pain localized at his neck and left shoulder. An MRI of the cervical spine showed an intramedular lesion with a demyelinative aspect extending from the level of the C4 disk to the C5 disk, and the presence of syringomyelia at the level of the C6 disk. The patient refused to undergo other diagnostic procedures. In 1998, he presented Lhermitte's sign. A reduction of the intramedular lesion and persistence of the hydrosyringomyelia was observed in a new MRI of the spine. An MRI of the brain revealed an isolated right capsular hyperintensive lesion in T2 and FLAIR. Serologies for HIV, the herpes virus, HTLV I-II and VDRL were negative, while evoked potentials were normal. In September of 1998, the patient was asymptomatic, his neurological examination was normal, and there were no changes in a control MRI. Clinical evolution and MRI findings suggest a primary demyelinative etiology of a spinal lesion, but a post-infectious mechanism cannot be ruled out. The pathogenesis of syringomyelia associated with demyelinative lesions remains unknown. One theory holds that the edema associated with plaque produces a mechanical obstruction to the normal cerebrospinal flow, generating the hydromyelia. Others believe that syringomyelia results from ex vacuo spinal atrophy. Although its low rate of incidence and the absence of pathognomonic radiological findings make diagnosis difficult, we believe that demyelinative etiology should be considered whenever an isolated spinal lesion is found in association with syringomyelia, as in these cases surgery would be contraindicated.
La siringomielia no comunicante ha sido descrita en asociación con diversas patologías medulares, pero raramente ha sido reportada en relación con lesiones desmielinizantes. Presentamos un paciente de 39 años, varón, con antecedentes de herpes zoster craneal en 1996 que evolucionó con omalgia izquierda y cervicalgia persistente. La resonancia magnética (RM) de médula cervical evidenció lesión intramedular focal a nivel C4-C5 de aspecto desmielinizante, y la presencia de hidrosiringomielia nivel C6. El paciente rehusó nuevos procedimientos. En 1998 agrega signo de Lhermitte. Una nueva RM espinal mostró reducción de la lesión intramedular cervical con persistencia de la siringomielia no comunicante. La RM cerebral objetivó una única lesión puntiforme en el brazo posterior de la cápsula interna derecha. Las serologías para HIV, herpes, HTLV I-II, VDRL y potenciales evocados fueron normales. En septiembre de 1998 se encontraba asintomático, con examen neurológico normal y sin cambios en el control por imágenes. La evolución clínica y hallazgos neurorradiológicos sugieren una lesión primariamente desmielinizante versus un mecanismo postinfeccioso La patogénesis de la siringomielia no comunicante asociada a lesiones desmielinizantes es discutida: se postula dilatación ependimaria mecánica por obstrucción al flujo del líquido cefalorraquídeo causado por el edema de la placa espinal, versus dilatación ependimaria secundaria a mielomalacia. Pese a su baja prevalencia y a la dificultad diagnóstica que plantea la ausencia de un patrón radiológico característico, la patología desmielinizante debería considerarse entre los diagnósticos diferenciales de lesiones intramedulares asociadas a hidromielia, ya que en estos casos el abordaje quirúrgico no estaría indicado.
