An Ex Vivo Study of Filum Terminale in Children and Fetuses Based on Optical Coherence Tomography.

Objective: To distinguish ex vivo normal and abnormal filum terminale (FT) in pathology based on optical coherence tomography (OCT). Methods: A total of 14 ex vivo FTs, freshly imaged via OCT after being cut, were excised from the scanned region for histopathological examination (HPE). Qualitative analysis was performed by 2 blinded assessors. Results: We performed OCT imaging of all specimens and validated them qualitatively. In the fetal FTs, we observed large amounts of fibrous tissue scattered throughout with a few capillaries but no adipose tissue. In tight filum terminale syndrome (TFTS), adipose infiltration and capillaries were significantly increased, with obvious fibroplasia and disarrangement. OCT images showed increased adipose tissue in which the adipocytes were arranged in a grid-like pattern; dense, disordered fibrous tissue and vascular-like tissue were present. The diagnostic results of OCT and HPE were consistent (Kappa = 0.659; P = .009, <.01), and there was no statistically significant difference in diagnosing TFTS using a Chi-square test (P > .05). The area under the curve (AUC) for OCT (AUC = 0.966; 95% CI, 0.903 to 1.000) was better than magnetic resonance imaging (MRI) (AUC = 0.649; 95% CI, 0.403 to 0.896). Conclusion: OCT can quickly obtain clear images of FT's inner structure, contribute to diagnosing TFTS and will be an indispensable complement to MRI and HPE. More FT sample studies in vivo are needed to confirm the high accuracy rate of OCT.

The correlation between cauda equina nerve root volume and sensory block height after spinal anaesthesia with glucose-free bupivacaine.

We examined the association between cauda equina nerve root volume and sensory block height in 15 patients undergoing spinal anaesthesia with 0.5% glucose-free bupivacaine. Magnetic resonance imaging and a separate image segmentation program were used to calculate the volume of the nerve roots. Nerve root volume was also correlated with lumbosacral cerebrospinal fluid volume and with patients' physical characteristics. Nerve root volume correlated negatively with sensory block height (Spearman rho -0.61 (95% CI -0.85 to -0.14)) and body mass index (Spearman rho -0.66 (95% CI -0.87 to -0.24)) but positively with cerebrospinal fluid volume (Spearman rho 0.76 (95% CI 0.43-0.91)). Factors that are thought to influence cerebrospinal fluid volume, such as body mass index, might similarly affect the volume of the nerve roots. The size of the nerve roots may influence the spread of spinal anaesthesia.

Chronic intrathecal infusion of gabapentin prevents nerve ligation-induced pain in rats.

BACKGROUND: Gabapentin is an anticonvulsant and adjuvant analgesic. It is effective in several pain studies. Neuropathic pain is the most difficult type of pain to treat. In this study, we examined if intrathecal gabapentin could prevent nerve injury-induced pain. METHODS: Under isoflurane anaesthesia, male Sprague-Dawley rats (200-250 g) underwent right L5/6 spinal nerve ligation and placement of an intrathecal catheter connected to an infusion pump. After surgery, intrathecal saline or gabapentin (20 µg h(-1)) was given for 7 days (n=8 per group). The right hind paw withdrawal threshold to von Frey filament stimuli and withdrawal latency to radiant heat were determined before (baseline) and once daily for 7 days after surgery. Haematoxylin and eosin and toluidine blue staining were used to evaluate the neurotoxicity of gabapentin (40 µg h(-1)). RESULTS: Seven days after nerve ligation, the affected paw withdrawal threshold and latency of saline-treated rats decreased from the baseline 11.7 (11.7-22.2) [median (inter-quartile range)] to 1.6 (0.9-3.2) g and 10.8 (10.5-11.2) to 4.3 (4.2-7) s, respectively. Rats receiving gabapentin (20 µg h(-1)) had higher withdrawal threshold [9.9 (9.9-19.3) g] and latency [11.5 (9.7-11.9) s] on day 7 after ligation. No obvious histopathological change or growth retardation was detected after intrathecal gabapentin (40 µg h(-1)) infusion. CONCLUSIONS: We showed a preventative effect of intrathecal gabapentin on the development of nerve injury-induced mechanical allodynia and thermal hyperalgesia. Our data suggest that continuous intrathecal gabapentin may be considered as an alternative for the prevention of nerve injury-induced pain.

Apoptosis of primary sensory neurons in GD1b-induced sensory ataxic neuropathy.

Experimental autoimmune sensory ataxic neuropathy was induced in three of six rabbits sensitized with GD1b ganglioside (GD1b-SAN). TUNEL assay was performed on sections of dorsal root ganglia in the cauda equina. The results showed the presence of TUNEL-positive neurons in all three rabbits affected with GD1b-SAN. In contrast, no such neurons were observed in any of the sections from the unaffected rabbits that had been inoculated with GD1b, rabbits inoculated with adjuvant alone or those without inoculation. These data support that an apoptotic mechanism is involved in the pathogenesis of GD1b-SAN.

Spinal arteriovenous fistulae with a concomitant cauda equina schwannoma.

BACKGROUND: Perimedullary spinal arteriovenous malformations or direct spinal arteriovenous fistulaes (AVFs) may be associated with other vascular abnormalities, such as arteriovenous malformations, venous ectasis, and aneurysms, but rarely have been reported with intraspinal intradural tumors. PURPOSE: The authors present an interesting case of type IV-A spinal AVF concomitant with a cauda equina schwannoma. STUDY DESIGN: The diagnostic procedures and surgical outcome were described. METHODS: The patient underwent surgery, the vessel feeding the AVFs was identified and cauterized, and the spinal tumor was removed. The fistula was small and located inside the tumor. The pathology revealed AVF and schwannoma, respectively. RESULTS: After surgery, the patient's symptoms began to improve and subside. Two years after surgery, follow-up magnetic resonance imaging showed no vascular lesion and tumor in the spinal canal. CONCLUSIONS: The association of spinal AVFs and cauda equina schwannoma has not been reported previously in any literature. The patient presents the symptoms of myelopathy associated with a spinal vascular lesion; it has to be noted that a concomitant and related intradural spinal tumor may exist.

Intracranial retrograde dissemination in filum terminale myxopapillary ependymomas.

Myxopapillary ependymomas (ME) are considered benign tumours (WHO grade I) of the central nervous system with long term survival rates and a tendency to local recurrence. However an aggressive course has occasionally been described, leading to CSF dissemination and even systemic metastases. We describe the case of a 23-year-old man diagnosed with intracranial subarachnoid dissemination of a filum terminale ME three years after the initial diagnosis. We have performed a careful review of the literature on CSF dissemination in ME and finally propose treatment of these cases.

Caudal spinal cord ischemia after lumbar vertebral manipulation.

Neurological complications after lumbar spine manipulation are uncommon. The cause is usually a herniated disk or displaced bony structure. We report a case of paraplegia that developed a few hours after manipulation of the lumbar spine. Magnetic resonance imaging was consistent with ischemia of the caudal spinal cord. No disk fragment or bony structure impinging on the spinal cord was seen. Spinal cord ischemia may deserve to be added to the list of possible adverse events after lumbar spine manipulation.

Estimulaçäo elétrica da medula espinal para o tratamento da dor crônica: resultados / Eletrical stimulation of spinal cord for the treatment of chronic pain

Os resultados do tratamento de 50 doentes através do método da neuroestimulaçao da medula espinal sao apresentados. A dor foi decorrente de lesao traumática do cone medular e das raízes da cauda eqüina em 8 doentes, lesao da medula espinal em 14, neuropatia pós-herpética em 6, distrofia simpático-reflexa em 8, fibrose peridural em 6, doença oncológica em 1, avulsao das raizes do plexo braquial em 4 e decorrente da amputaçao de membros em 3 (dor em membro fantasma em 2 e no coto de amputaçao em 1). Os resultados foram considerados bons e excelentes, durante o período de seguimento, em 26 doentes (52 por cento). Vinte e quatro (48 por cento) nao se beneficiaram com a estimulaçao elétrica da medula espinal. Em 2 doentes o sistema implantado teve que ser removido devido a infecçao. Um dos doentes apresentou complicaçoes transitórias decorrentes de síndrome cordonal posterior. A estimulaçao elétríca da medula espinal nao contribuiu para o alívio da dor em 7 doentes com lesao traumática da medula espinal e raízes da cauda eqüina. Um doente teve excelente resultado após o implante; entretanto, observou-se recorrência da dor durante o acompanhamento clínico.Em 7 doentes com mielopatia, o resultado satisfatório obtido com o implante permaneceu durante o período de seguimento (mediana de 8,9 meses). Em doentes com nevralgia pós-herpética foram observados resultados bons e excelentes após o ato operatório; no entanto, foram observadas recorrência parcial da dor em l e recorrência total em outro. Dentre os 7 doentes com distrofia simpático-reflexa, a estimulaçao da medula espinal resultou no alívio imediato e persistente da sintomatologia em 6. Um doente apresentou recorrência da dor. A estimulaçao elétrica da medula espinal propiciou alívio imediato da dor em 2 doentes com avulsao das raizes do plexo braquial. Entretanto, a dor recorreu em 1.Um doente com dor no coto de amputaçao e 2 com dor no membro fantasma nao apresentaram alívio com estimulaçao elétrica da medula espinal. O doente com dor oncológica visceral apresentou resultado satisfatório durante os 2 últimos meses de vida.Baseado na análise deste trabalho, é possível concluir que a estimulaçao elétríca da medula espinal é especialmente recomendada para o tratamento das síndromes neuropáticas com lesao mínima ou parcial das estruturas nervosas, como as que ocorrem em casos de distrofia simpático-reflexa, radiculopatias ou lesao parcial da medula espinal.

[An autopsy case of olivocerebellar and thalamic degeneration, diffuse sclerosis and hypertrophic neuropathy: infantile system degeneration? (author's transl)]. / Ein Autopsiefall von olivocerebellarer und Thalamusdegeneration, diffuser Marksklerose und hypertrophischer Neuropathie: frühkindliche Systemerkrankung

The brain of a 21-year-old man with imbecility and spastic tetraplegia since early childhood showed a diffuse sclerosis of the cerebral white matter and symmetrical degeneration of the thalamus and olivocerebellar system. The spinal nerve roots as well as proximal branches of the spinal nerves were hypertrophic and there was seen a marked fibrosis with some onion-bulb formations of Schwann cells. In spite of a possible relation to an unknown infection at the age of 3 months this case could preferably be regarded as a peculiar form of the combined system degeneration in the early childhood, including the cerebral white matter and peripheral nerves. An uncle of the patient had died of a similar nervous disease at the age of 20 years.