Aracnoides trabecular, piamadre espinal humana y anestesia subaracnoidea / Trabecular arachnoid membrane, human spinal piamater and subarachnoid anesthesia

En los textos de anestesiología se aportan pocos detalles sobre la aracnoides trabecular y la piamadre espinal humana, a pesar de ser estructuras íntimamente relacionadas con los anestésicos locales administrados en una anestesia subaracnoidea. Complicaciones tales como el síndrome de cauda equina y el síndrome de irritación radicular transitorio posterior a la realización de bloqueos subaracnoideos, sumado a la alta permeabilidad que ha sido asociada con la piamadre, nos ha motivado a investigar sobre la ultraestructura de estas meninges. Método. Las muestras estudiadas se tomaron de cadáveres recientes y fueron examinadas por microscopía electrónica de transmisión y de barrido. Resultados. El trabeculado aracnoideo rodeaba a las raíces nerviosas, a la médula y a los vasos que se encontraban dentro del espacio subaracnoideo, limitando zonas. La piamadre estaba formada por un plano celular y por un compartimiento subpial. En el plano celular existían perforaciones naturales, especialmente en la región del cono medular y en las raíces nerviosas. Conclusiones. La inyección accidental de anestésicos locales dentro de las fundas que formaban el trabeculado aracnoideo podría justificar una dilución inadecuada de estas soluciones y el origen de síndromes neurotóxicos transitorios o permanentes. La alta permeabilidad de la piamadre podría deberse, en parte, a la existencia de perforaciones naturales, las cuales facilitarían un pasaje rápido de las sustancias introducidas en el líquido cefalorraquídeo hacia las raíces nerviosas y la médula espinal. En este caso, la membrana basal ubicada por debajo de las fibras colágenas del compartimiento subpial sería la única estructura limitante previa al tejido glio-neuronal de la médula.

Few details are to be found in anesthesiology texts concerning the trabecular arachnoid membrane and the human spinal pia mater in spite of being structures that are intimately related to local anesthetics administered in subarachnoid anesthesia. We were driven to investigate the ultrastructure of these meninges by complications such as the cauda equina syndrome and the transitory radicular irritation syndrome following subarachnoid blocks, added to the high permeability associated to the pia mater. Method. The samples analyzed were taken from recently deceased cadavers and were examined under transmission and scanning electron microscopy. Results. The arachnoid trabeculation surrounded the nerve roots, the spinal cord and the vessels within the subarachnoid space, limiting areas. The pia mater was formed by a cellular plane and by a sub-pial compartment. There were natural perforations in the cellular plane, particularly in the medullar cone region and the nerve roots. Conclusions. Accidental injection of local anesthetics into the sheaths formed by arachnoid trabeculation could be the cause of inadequate dilution of these solutions and the source of transitory or permanent neurotoxic syndromes. The high permeability of the pia mater could be partly due to the existence of natural perforations, which enable the quick passage of the substances introduced in the cerebrospinal fluid into the nerve roots and spinal cord. ln this case, the basal membrane located underneath the collagen fibers of the subpial compartment would be the only limiting structure before the glioneural tissue of the spinal cord.

Os textos de anestesiologia fornecem poucos detalhes sobre a aracnóide trabecular e a pia-máter espinhal humana, apesar delas serem estruturas intimamente relacionadas com os anestésicos locais administrados em uma anestesia subaracnóidea. Complicações tais como a síndrome de cauda eqüina e a síndrome de irritação radicular transitória posterior a bloqueios subaracnóideosas quais se soma a alta permeabilidade, que tem sido associada à pia-máter -levou-nos a pesquisar a ultraestrutura dessas meninges. Método. As amostras estudadas foram coletadas de cadáveres recentes e examinadas por microscopia eletrónica de transmissão e de varredura. Resultados. A trabeculação aracnóidea rodea va as raízes nervosas, a medula e os vasos no interior do espaço subaracnóide, limitando zonas. A pia-máter estava formada por um plano celular e um espaço subpial. No plano celular existiam perfurações naturais, especialmente na regiáo do cone medular e nas raízes nervosas. Conclusóes. A injeção acidental de anestésicos locais no interior das coberturas que formavam a trabeculação aracnoidea poderia justificar uma diluição inadequada das soluções e a origem de síndromes neurotóxicas transitórias ou permanentes. A causa da alta permeabilidade da pia-máter seria, em parte, a existencia de perfurações naturais que facilitariam a rápida passagem das substancias introduzidas no líquido cefalorraquiano para as raizes nervosas e a medula espinhal. Neste caso, a membrana basal localizada abaixo das fibras colágenas do espaço subpial seria a única estrutura limitante anterior ao tecido glio-neuronal da medula.

Cytomegalovirus polyradiculomyelopathy in AIDS: a case report and review of the literature

Cytomegalovirus (CMV) neurologic disease is a serious complication of the acquired immunodeficiency virus (AIDS). We report the case of a 40 year-old woman with AIDS who presented paralysis of lower extremities, areflexia, sensory loss, and urinary retention. CMV polymerase chain reaction (PCR) of cerebrospinal fluid (CSF) allowed confirmation of CMV polyradiculomyelopathy (PRAM).

Sacro-iliac tuberculosis presenting as cauda equina syndrome

Tuberculosis affecting the bone and spine has been a common problem in the developing countries for quite some time. Though the incidence has decreased dramatically, it still continues to be an important differential diagnosis in certain clinical situations. We hereby describe a patient who presented with features of cauda equine syndrome; the diagnosis was ultimately tuberculosis primarily involving the sacroiliac joint extending through the neural foramen and causing extradural compression

Sudden bilateral foot drop: an unusual presentation of lumbar disc prolapse.

Bilateral acute foot drop is reported in a 30-year-old healthy male. He presented with a 7-day history of sudden severe backache, radiating to both the lower limbs and 1-day history of sudden bilateral ankle weakness that progressed to bilateral foot drop within 6 hours. He also developed retention of urine. Investigations revealed a large central disc prolapse at L3-4 with significant canal stenosis at that level. Following surgery the patient had progressive improvement.

Cauda equina syndrome caused by tuberculous sacroilitis

Tuberculosis of the sacroiliac joint relatively rare and can yield variable clinical manifestation. This study describes a 39-year-old man who developed a rare condition of tuberculous arthritis of the right sacroiliac joint, with an abscess formation, which invaded the extradural space and caused cauda equina syndrome. The clinical manifestation, physical findings, computed tomography scan, and results after surgical treatment of this patient are discussed

Extramedullary astrocytoma of conus region : a short report.

A 55 year old man presented with features of cauda equina syndrome. Magnetic resonance imaging (MRI) showed a well demarcated intradural extramedullary tumour at L2 vertebra. At surgery it was found to be well encapsulated and had no attachment to spinal cord or root. Histopathology including immunohistochemistry confirmed it to be a low grade astrocytoma.

Neurobrucellosis in South Tunisia

A new epidemic of brucellosis appeared in Tunisia since 1989 and neurological was observed in some cases. We report 5 neurobrucellosis patients originating from south Tunisia, their mean age was 47 years. General symptoms included headache and moderate fever. Neurological examination demonstrated paraplegia in 4 cases and hemiparesis one. Treatment associated cotrimoxazo, reframing and tetracycline for a mean duration of 10 months. Compete recovery or imorovement was observed in 4 cases. For the last case, she remained bedridden. Our series demonstrated the wide spectrum of neurological presentation of neurobrcellosis and the efficiency of specific treatment. The disappearance of human brucellosis in developing countries requires hygienic processing of milk and eradication of infection from carrier animals. Neurologists in developing countries should be aware about diverse presentation neurobrucellosis