Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis / Associação entre a presença de raízes redundantes na cauda equina e a área seccional do saco dural avaliada por meio de ressonância magnética

To evaluate the association of redundant nerve roots of cauda equina (RNRCE) with the degree of lumbar spinal stenosis (LSS) and with spondylolisthesis. Method After Institutional Board approval, 171 consecutive patients were retrospectively enrolled, 105 LSS patients and 66 patients without stenosis. The dural sac cross-sectional area (CSA) was measured on T2w axial MRI at the level of L2-3, L3-4 and L4-5 intervertebral discs. Two blinded radiologists classified cases as exhibiting or not RNRCE in MRI. Intra- and inter-observer reproducibility was assessed. Results RNRCE were associated with LSS. RRNCE was more frequent when maximum stenosis<55 mm2. Substantial intra- observer agreement and moderate inter-observer agreement were obtained in the classification of RNRCE. Spondylolisthesis was identified in 27 patients and represented increased risk for RRNCE. Conclusion LSS is a risk factor for RNRCE, especially for dural sac CSA<55 mm2. LSS and spondylolisthesis are independent risk factors for RNRCE. .

Avaliar associação entre raízes nervosas redundantes da cauda eqüina (RNRCE) com grau de estenose do canal lombar (ECL) e espondilolistese. Método Após aprovação do Comitê de Ética, 171 pacientes foram selecionados retrospectivamente, 105 com ECL e 66 sem estenose. Foram realizadas mensurações da área seccional do saco dural em imagens axiais de RM ponderadas em T2 em L2/L3, L3/L4 e L4/L5. Presença ou não de RRNCE foi classificada de forma independente por dois radiologistas, às cegas. Concordância intra e inter-observador foi analisada. Resultados RNRCE foi associada à ECL e foi mais freqüente quando a máxima estenose encontrada foi <55mm2. Houve grande concordância intra-observador e moderada inter-observador na classificação das RRNCE. Espondilolistese foi identificada em 27 pacientes e representou maior risco para desenvolvimento de RNRCE. Conclusão ECL é fator de risco para RNRCE, especialmente com áreas seccionais <55mm2. ECL e espondilolistese representam fatores de risco independentes para desenvolvimento de RNRCE. .

Polirradiculopatía inflamatoria crónica sensitiva / Chronic inflammatory sensory polyradiculopathy

La polirradiculopatía inflamatoria crónica sensitiva es una entidad definida, frecuentemente subdiagnosticada y potencialmente tratable. Debe ser sospechada en pacientes con ataxia sensitiva, estudios de conducción nerviosa normales y una resonancia magnética que muestre engrosamiento y realce con gadolinio de las raíces lumbosacras. Presentamos el caso de un hombre de 57 años de edad con marcada ataxia sensitiva en pierna izquierda. Al examen físico presentaba fuerza conservada, reflejos osteotendinosos disminuidos, tacto fino y superficial reducidos por debajo de las rodillas; abatiestesia y apalestesia en ambos pies. Los estudios de conducción nerviosa eran normales, los potenciales evocados somatosensitivos tibiales con ausencia de respuesta bilateral. El líquido cefalorraquídeo presentaba hiperproteinorraquia sin células. La resonancia magnética mostró engrosamiento y realce con gadolinio de las raíces lumbosacras. El paciente fue tratado con inmunoglobulina endovenosa (IgEV) a 2 g/kg durante 5 días, con buena respuesta. La evolución clínica, la hiperproteinorraquia, el realce de raíces en la resonancia magnética, la buena respuesta a la inmunoterapia y la exclusión de otras causas de ataxia sensitiva fueron compatibles con el diagnóstico de polirradiculopatía inflamatoria crónica sensitiva. Para el diagnóstico de esta enfermedad se requiere la identificación del compromiso aislado de las raíces sensitivas.

Chronic inflammatory sensory polyradiculopathy is a defined entity, frequently underdiagnosed, and potentially treatable. It must be suspected in patients with sensory ataxia, normal nerve conduction studies, and MRI with thickened lumbosacral nerve roots and gadolinium enhancement. We present the case of a 57-year-old man with marked sensory ataxia on his left leg. Examination showed normal strength, decreased knee and ankle jerks. Light touch and pinprick sensations were reduced below the knees. Vibration and joint position sense were absent at the feet. Nerve conduction studies were normal. Tibial sensory evoked potentials disclosed absent responses bilaterally. CSF was acellular with elevated protein. Lumbosacral magnetic resonance showed thickening of roots, with gadolinium enhancement. The patient was treated with IV-Ig, 2 g/kg, for 5 days with improvement of symptoms. The clinical course, elevated CSF protein, the evidence of root enhancement on the MRI, good response to immunotherapy, and the exclusion of other causes of sensory ataxia, were compatible with the diagnosis of chronic inflammatory sensory polyradiculopathy. To diagnose this disease the identification of isolated involvement of the sensory roots is required.

Efeitos antinociceptivos, analgésicos e histopatológicos de dexmedetomidina e bupivacaína intratecal em rato / Anti-nociceptive, analgesic and pathohistological effects of intrathecal dexmedetomidine and bupivacaine in rats / Efectos antinociceptivos, analgésicos e histopatológicos de dexmedetomidina y bupivacaína intratecal en ratones

JUSTIFICATIVA E OBJETIVOS: Este estudo investigou os efeitos analgésicos e nociceptivos da adição de dexmedetomidina à bupivacaína em anestesia do neuroeixo usando os testes de retirada da cauda (tail-flick [TF]) e da placa quente (hot-plate [HP]) e microscopia de luz para as alterações histopatológicas de nervos espinhais e raízes nervosas. MÉTODOS: Quarenta ratos Sprague-Dawley anestesiados, machos, foram cateterizados intratecalmente. Os valores basais dos testes TF e HP foram medidos antes e depois do cateterismo. Trinta e seis ratos cateterizados com sucesso foram distribuídos em quatro grupos. O Grupo B recebeu 10 µg de bupivacaína, o Grupo BD3 recebeu 10 µg de bupivacaína + 3 µg de dexmedetomidina, o Grupo BD10 recebeu 10 µg de bupivacaína + 10 µg de dexmedetomidina e o Grupo Controle recebeu 10 µL de líquido cefalorraquidiano artificial. Os testes TF e HP foram feitos entre cinco e 300 minutos a partir da administração das drogas. Vinte e quatro horas após a administração, os ratos foram sacrificados e retiradas as medulas espinhais e raízes nervosas para investigação patológica. RESULTADOS: Os valores basais dos testes TF e HP não foram estatisticamente diferentes entre os grupos (6,8 ± 0,15 s). As latências de TF e HP no Grupo Controle não apresentaram alteração significativa durante o estudo. Os resultados dos testes TF e HP mostraram que a adição de 3 e 10 µg de dexmedetomidina causou um aumento dose-dependente na duração e amplitude do efeito analgésico e nociceptivo de bupivacaína (TF: 37,52 ± 1,08%, 57,86 ± 1,16%, respectivamente; HP: 44,24 ± 1,15%, 68,43 ± 1,24%, respectivamente). CONCLUSÕES: Não houve alterações histopatológicas aparentes em pelo menos 24 horas após a administração intratecal da dose única de dexmedetomidina (3 µg e 10 µg). Dexmedetomidina adicionado à bupivacaína para raquianestesia melhora a analgesia e prolonga a duração do bloqueio.

BACKGROUND AND OBJECTIVES: This study investigates analgesic and nociceptive effects of adding dexmedetomidine to bupivacaine neuraxial anesthesia through Tail-flick (TF) and Hot-plate (HP) tests and the pathohistological changes on spinal nerves and nerve roots through light microscopy. METHODS: Forty anesthetized, male Sprague-Dawley rats were intrathecally catheterized. Basal values of TF and HP tests were measured before and after catheterization. Thirty-six successfully catheterized rats were assigned to four groups. Group B received 10 µg bupivacaine, Group BD3 received 10 µg bupivacaine + 3 µg dexmedetomidine, Group BD10 received 10 µg bupivacaine + 10 µg dexmedetomidine and Control group received 10 µL volume of artificial cerebrospinal fluid. TF and HP tests were performed between the 5th and 300th minutes of drug administration. Twenty-four hours after administration of drugs, rats were sacrificed and spinal cord and nerve roots were removed for pathological investigation. RESULTS: Baseline values of the TF and HP tests were not statistically different among the groups (6.8 ± 0.15 s). TF and HP latencies in the Control group did not change significantly during the study. TF and HP test results showed that adding 3 and 10 µg dexmedetomidine caused a dosedependent increase in duration and amplitude of analgesic and nociceptive effect of bupivacaine (TF: 37.52 ± 1.08%, 57.86 ± 1.16% respectively, HP: 44.24 ± 1.15%, 68.43 ± 1.24% respectively). CONCLUSIONS: There were no apparent pathohistological changes at least 24 hours after the intrathecal administration of a single dose of dexmedetomidine 3 µg and 10 µg. Dexmedetomidine added to bupivacaine for spinal block improves analgesia and prolongs block duration.

JUSTIFICATIVAS Y OBJETIVOS: Este estudio investigó los efectos analgésicos y nociceptivos de la adición de dexmedetomidina a la bupivacaína en anestesia del neuro eje, usando los test de retirada de la cola (tail-flick [TF]) y de la placa caliente (hot-plate [HP]) y microscopía de luz para las alteraciones histopatológicas de nervios espinales y raíces nerviosas. MÉTODOS: Cuarenta ratones anestesiados, Sprague-Dawley machos, fueron cateterizados intratecalmente. Los valores basales de los testes TF y HP fueron medidos antes y después del cateterismo. Treinta y seis ratones cateterizados con éxito fueron distribuidos en cuatro grupos. El Grupo B recibió 10 µg de bupivacaína, el Grupo BD3 recibió 10 µg de bupivacaína + 3 µg de dexmedetomidina, el Grupo BD10 recibió 10 µg de bupivacaína + 10 µg de dexmedetomidina y el Grupo Control recibió 10 µL de líquido cefalorraquídeo artificial. Los test TF y HP se hicieron entre cinco y 300 minutos a partir de la administración de los fármacos. Veinte y cuatro horas después de la administración, los ratones fueron sacrificados y se les retiraron las médulas espinales y las raíces nerviosas para investigación patológica. RESULTADOS: Los valores basales de los test TF y HP no fueron estadísticamente diferentes entre los grupos (6,8 ± 0,15 s). Las latencias de TF y HP en el Grupo Control no tenían ninguna alteración significativa durante el estudio. Los resultados de los test TF y HP mostraron que la adición de 3 y 10 µg de dexmedetomidina causó un aumento dosis dependiente en la duración y en la amplitud del efecto analgésico y nociceptivo de bupivacaína (TF: 37,52 ± 1,08%, 57,86 ± 1,16%, respectivamente; HP: 44,24 ± 1,15%, 68,43 ± 1,24%, respectivamente). CONCLUSIONES: No hubo alteraciones histopatológicas aparentes en por lo menos 24 horas después de la administración intratecal de la dosis única de dexmedetomidina (3 µg y 10 µg). Dexmedetomidina añadido a la bupivacaína para raquianestesia mejora y prolonga la duración del bloqueo.

uncommon cause of sciatica

A 67-year-old male patient underwent a left nephrectomy for a renal cell carcinoma. Thirty-eight months later, he presented with right sided lower backache, radiating to the posterior aspect of his thigh, calf and foot, paraesthesiae and numbness in the distribution of the right S1 and S2 dermatomes. The presumptive diagnosis was of nerve root entrapment secondary to a disc prolapse. MRI scan of the lumbosacral spine revealed an enlarged S1 root canal containing a solid solitary lesion suggestive of a neurofibroma of the S1 nerve root. Because of persistent pain, he underwent a right L5/S1 hemilaminectomy. A lesion originating from the right S2 nerve root was found and excised. The patient made an uneventful postoperative recovery with complete resolution of his right leg pain. The histopathological examination revealed a portion of the nerve root and dorsal root ganglion infiltrated by metastatic renal cell carcinoma. Although uncommon, nerve root infiltration by a metastasis should be included in the differential diagnosis of back pain and sciatica, especially if there is a previous history of malignant disease

Ultrastructural changes of compressed lumbar ventral nerve roots following decompression

To study whether there will be a permanent lumbar nerve root scarring or degeneration secondary to continuous compression followed by decompression on the nerve roots, which can account for postlaminectomy leg weakness or back pain. The study was performed at the Department of Anatomy, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia during 2003-2005. Twenty-six adult male New Zealand rabbits were used in the present study. The ventral roots of the left fourth lumbar nerve were clamped for 2 weeks then decompression was allowed by removal of the clips. The left ventral roots of the fourth lumbar nerve were excised for electron microscopic study. One week after nerve root decompression, the ventral root peripheral to the site of compression showed signs of Wallerian degeneration together with signs of regeneration. Schwann cells and myelinated nerve fibers showed severe degenerative changes. Two weeks after decompression, the endoneurium of the ventral root showed extensive edema with an increase in the regenerating myelinated and unmyelinated nerve fibers, and fibroblasts proliferation. Three weeks after decompression, the endoneurium showed an increase in the regenerating myelinated and unmyelinated nerve fibers with diminution of the endoneurial edema, and number of macrophages and an increase in collagen fibrils. Five and 6 weeks after decompression, the endoneurium showed marked diminution of the edema, macrophages, mast cells and fibroblasts. The endoneurium was filled of myelinated and unmyelinated nerve fibers and collagen fibrils. Decompression of the compressed roots of a spinal nerve is followed by regeneration of the nerve fibers and nerve recovery without endoneurial scarring

Chronic inflammatory demyelinating polyradiculoneuropathy: two cases with cervical spinal cord compression

A polirradiculoneuropatia desmielinizante inflamatória crônica (PDIC) é uma afecção dos nervos periféricos de natureza autoimune, com evolução por surtos de exacerbação e remissão ou de evolver progressivo. O acometimento motor é predominante, com fraqueza proximal e distal nos membros inferiores. A eletroneuromiografia é do tipo desmielinizante com bloqueio de condução nervosa em dois ou mais nervos. Há aumento de proteínas do líquor. Com a evolução da doença pode haver espessamento dos nervos distal e/ou proximalmente. Excepcionalmente ocorre compressão da medula espinhal em qualquer segmento por raízes próximas hipertrofiadas. Foram estudadas duas mulheres de 66 e 67 anos respectivamente com quadro de PDIC de longa evolução. A primeira tinha evolução por surtos e na segunda o evolver era progressivo. Nos dois casos o espessamento proximal dos nervos provocou síndrome de compressão medular alta. Esta complicação deve ser pensada em casos de PDIC de longa duração.

C-1 Root Schwannoma with Aggressive Lateral Mass Invasion

Schwannomas are relatively common, benign tumors that are thought to arise from the nerve sheath cell. Schwannomas of the C1 root are extremely rare and seldom invade lateral masses because they gradually increase in size and can extend through the wide space behind the lateral mass instead of the intervertebral foramen. We present here an unusual case of a benign schwannoma that aggressively invaded the lateral mass of C-1.

Primary Malignant Melanoma of the Cervical Spinal Nerve Root

The authors report on a case of primary malignant melanoma of the 7th cervical spinal nerve root in a 45-year-old woman. Neuro-radiological features of this extra-dural mass were suggestive of a nerve sheath tumor. The lesion underwent total gross resection through the anterolateral approach. The patient's postoperative course was uneventful. Histopathological investigation confirmed malignant melanoma. There was no evidence of tumor recurrence or other melanotic lesions on regular follow-up examinations until the postoperative eighth month. When treating a common, benign-looking lesion of the cervical spinal nerve root, surgeons should be aware of the potential to encounter such a malignant tumor.

Effect of ischaemia & aglycaemia on the synaptic transmission in neonatal rat spinal cord in vitro.

BACKGROUND & OBJECTIVES: In vitro models of anoxia have revealed severe changes in neuronal functions after ischaemia but not after aglycaemia, although hypoglycaemia produced severe neuronal dysfunctions sometimes leading to coma. The present study was therefore undertaken to examine and compare the effects of aglycaemia with that of ischaemia on synaptic transmission in vitro. METHODS: Spinal cord from the neonatal rat was isolated, hemisected and placed in a chamber perfused with standard physiological solution. The stimulation of a dorsal root elicited monosynaptic (MSR) and polysynaptic (PSR) reflex potentials in the segmental ventral root. The effects of suprefusing glucose free medium (aglycaemia) and superfusing glucose free and O2 free medium (ischaemia) were examined on these reflexes. RESULTS: Superfusion of aglycaemic solution did not alter the magnitude of MSR or PSR in the first 15 min and subsequently there was a time-dependent depression of the reflexes (P < 0.05). The ischaemic solution depressed the reflexes in a time-dependent manner from the very beginning. The 50 per cent depression of the reflexes occurred around 25 and 15 min, for aglycaemia and ischaemia, respectively. In the presence of Mg2+, the aglycaemia-induced depression of MSR was completely blocked but the ischaemic response was attenuated partially as the reflex was abolished by 80 min. INTERPRETATION & CONCLUSION: The results of the present study indicate that the aglycaemia and ischaemia depressed the synaptic transmission to the same extent though there were differences in their onset and progress. Aglycaemia involves N-methyl-D-aspartate (NMDA) receptor-dependent (Mg2+ sensitive) mechanism, while ischaemia-induced depression involves other mechanisms in addition to NMDA.

Sacral nerve root cysts: A review on pathophysiology.

Nerve root cysts of the sacral region are generally asymptomatic but are known to cause neurogenic claudication. In this paper we present an elderly lady who presented with claudication, whose MR imaging showed a sacral cyst. She underwent lumbo-sacral laminectomy, partial excision of the cyst wall with plication. A review of the possible pathophysiology of such a lesion is discussed.

Algunos aspéctos del Sindrome de la Región Lumbar / Aspects in Lumbar Syndrome

Se analiza el Sindrome Lumbar en sus tre variantes: hernia del disco, canal estrecho y anomalia radicular. El trabajo se fundamenta en 3200 casos de hernia del nucleo pulposo operados en los 50 años de funcionamiento del Servicio de Neurocirugia del Hospital Nacional Guillermo Almenara Irigoyen. Se destaca la importancia de la cirugia con la tecnica de Love en la patologia lumbar que hasta 1946 era considerada patrimonio de la traumatologia y ortopedia. Luego se valora el diametro del canal raquideo señalado por Verbiest con la descripcion del sindrome del canal estrecho congenito y adquirido, relevando el trayecto radicular y extradural de la raiz. Finalmente se resalta la importancia de las anomalias radiculares señaladas por Cannon con el trascendente aporte de la imagenologia, en especial la tomografia axial computarizada y la resonancia magnetica. Estos avances tecnologicos y de procedimientos han disminuido la persistencia del dolor lumbar post quirurgico de 30-35 por ciento hasta 2-5 por ciento. Se destaca la importancia de las intervenciones antes del sufrimiento radicular. No se ha considerado los sindromes dolorosos por inestabilidad del segmento ni por listesis congenita

Encephaloradiculopathy: a non-metastatic complication of hepatocellular carcinoma.

We describe a patient with a silent hepatocellular carcinoma in whom a progressive dysfunction developed in the brainstem, cerebrum, and cerebellum. This clinical manifestation was also associated with polyradiculopathy. The changes were microscopically unlike those seen in hepatic encephalopathy, progressive multifocal leukoencephalopathy and other metabolic encephalopathy. The findings seem to have occurred as a paraneoplastic syndrome of the nervous system. Although in the present case, the cause-and-effect relationship between the hepatocellular carcinoma and the encephaloradiculopathy is only hypothetical, we suggest that the demyelinating process which involves both central and peripheral nervous system in our case resulted from interaction of tumor with the host-immunological mechanism. The neurological presentation in our case is unique and has never been reported before.

Drematomal somatosensory evoked potentials (DSSEP) in patients with proved lumbosacral radiculopathies

Se llevó a cabo el estudio de potenciales evocados dermatómicos en 14 pacientes con afectación probada de raíces L5 o S1 o ambas unilateralmente. El estímulo se produjo en el área de piel correspondiente a la metamera deseada y el registro se efectuó en la corteza parietal de recepción contralateral. Los resultados fueron comparados con un grupo control sano, se observó que la técnica fue capaz de identificar a la lesión a través de dos tipos de hallazgos, uno fue el retraso en la latencia de la onda N1 y el segundo la ausencia de respuesta evocada