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Results for “Arachnoiditis”

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At least 19 recordsLinked to original sources

PubMed1978

Anterior cervical arachnoid cyst simulating syringomyelia: a case with preceding posterior arachnoid cysts.

An arachnoid cyst lying anterior to the cervical cord at level C6-7 was found in a 28-year-old woman believed to have syringomyelia. This diagnosis was based both on previous findings at laminectomy and on computerized tomography. The diagnosis of arachnoid cyst was suspected because of clinical features atypical for classical syringomyelia and a history of arachnoid cysts found during childhood. Air myelography demonstrated an extramedullary intradural mass anteriorly that proved to be an arachnoid cyst. Drainage and subtotal resection resulted in marked clinical improvement. This case illustrates the need for reevaluation when a patient with "known" syringomyelia presents an atypical clinical picture. Anterior cervical arachnoid cyst, which may accompany or succeed posterior arachnoid cysts, should be considered.

Adolescent↗

PubMedDate not supplied

[Ultrastructure of the cellular patches of the arachnoid membrane of the human brain (concerning the origin of the arachnoid-endothelial cleavages of the cerebral dura mater). Electron microscopic study].

The ultrastructure of cellular spots was studied--growths of the external arachnoidendothelial layer of the arachnoid membrane of the human cerebral hemispheres. The peculiarities of their ultrastructure depending on the stage of their development were revealed. "Young", cellular spots were formed by accumulations of osmiophobic round-shaped cells that are lined from the outside by osmiophilic cells like the whole of the arachnoid membrane surface. "Mature" cellular spots contain great number of oxmiophobic (viable) cells located in a immediate proximity of the subdural space, and they form the main source of viable arachnoidenodthelial cells found in the subdural fluid. The author believes that these cells penetrate together with the subdural fluid flow into the dura mater where, under specific conditions, they may become a source of arachnoidendothelial chippings.

Adult↗

PubMed1978

Arachnoiditis from experimental myelography with aqueous contrast media.

Myelography was performed on 80 monkeys to study postmyelographic arachnoiditis. Metrizamide myelography caused arachnoiditis when high concentrations were used, but not with the usual clinical concentrations. Arachnoiditis resulted after myelography with meglumine iocarmate; however, the risk of arachnoiditis was reduced by diluting the contrast medium. Prophylactic intrathecal methylprednisolone was not effective in preventing arachnoiditis. Blood in the cerebrospinal fluid did not affect the degree of arachnoiditis.

Animals↗

PubMed1978

Calcified congenital arachnoid cyst with heterotopic neuroglia in wall.

Two unique findings, advanced calcification and ectopic neuroglia, were encountered in the wall of a giant congenital arachnoid cyst occurring in a 40 year old woman. The cyst almost totally filled the supratentorial subdural space of the left hemicranial cavity, was not connected with the subarachnoid space, and thus developed intra-arachnoidally. Its congenitally derived nature was supported by the unique finding of heterotopic neuroglia in the wall. Congenital arachnoid cyst must be distinguished from various cystic lesions within the central nervous system, including the neuroepithelial cyst which can arise throughout the neuraxis. It is suggested that pathogenesis of the congenital arachnoid cyst is related to aberrant flow of the ventricular cerebrospinal fluid into the developing leptomeninx in the process of differentiation of the subarachnoid space. The tract or pouch may occur within the arachnoid mater, and the cyst is formed intra-arachnoidally when the former filled with fluid is closed off from the subarachnoid space.

Adult↗

PubMed1992

[Experimental syringomyelia in rabbits and rats after localized spinal arachnoiditis].

In order to produce syringomyelia, localized arachnoiditis was created in adult New Zealand albino rabbits and Wistar rats by the injection of kaolin into the thoracic spinal subarachnoid space and incision of the dura mater of the thoracic spinal cord. The rabbits and rats were divided into 3 groups; the control group, dural incision group (DG) and kaolin injection group (KG). Each rabbit was sacrificed at 4, 8, 12 and 16 weeks after the operation. Each rat was sacrificed at 8 and 16 weeks after the operation. Cavity formation in the cord of all rabbits was examined by ultrasound. All animals were perfused with 10% neutral beffered formalin at 150 cm H2O pressure, and histological examination was performed with Luxol fast blue (LFB) and hematoxylin and eosin (H&E) stains. Results obtained: (1) Cavity formation was noted in 6 of 16 DG of rabbit (37.5%), 5 of 16 KG of rabbit (31.2%) and 2 of 9 KG of rat (22.2%) with histological verification. With use of ultrasound, cavity was noted in 3 of 16 DG rabbits (12.5%) and 2 of 16 KG rabbits (18.8%). (2) Cavity formation was present in the cord adjacent to the marked adhesive arachnoiditis both in rabbits and in rats. (3) Cavity was noted in the ischemic area. (4) In 2 rabbits in which kaolin encircled whole surface of the spinal cord, hydromyelia was formed communicating with enlarged central canal caudad from the kaolin subarachnoid block. (5) Histological examination showed obliteration or narrowing of lumen of the small pial vessels involved in the adhesive arachnoiditis. In the cord parenchyma adjacent to the arachnoiditis, multiple spots of demyelination due secondary to ischemia demonstrated by LFB stain were noted. On the other hand, in the cord with the pia-arachnoid remained uninvolved, no demyelination was observed. (6) Localized adhesive arachnoiditis consisted of proliferation of fibrous tissue, lymphocytic infiltration and obliterating processes of small pial vessels involved in it. These data suggest that the cavitation within the cord would be induced by the ischemia, and hydromyelia would be produced by the pressure dissociation between the spinal subarachnoid space and the central canal.

Animals↗

PubMed1979

Long-term observation of arachnoid villi after subarachnoid hemorrhage: an electron microscopic study in dogs.

The sequential electron microscopic examinations were carried out on arachnoid villi of the dog after subarachnoid hemorrhage (SAH). A few days after SAH, red blood cells were accumulated and degenerated in the villi. 10 days after SAH, remarkable phagocytosis and micropinocytosis were observed in the arachnoid villi, which may suggest increased metabolic activity of the arachnoid cells. 30 days after SAH, increased cellularity in the arachnoid villi developed and intercellular spaces became very narrow. 90 days after SAH, the arachnoid villi demonstrated many cytoplasmic filaments and hemidesmosome-like structures in the arachnoid cells, as well as narrowed intercellular space and increased cellularity. Microfibrils increased and structures resembling basal laminae were observed in the stromas. These morphological alterations may have a relation to the disturbance of absorption of cerebrospinal fluid.

Animals↗

PubMed1977

[Development of arachnoid granulations].

The ontogenesis of arachnoid granulations has been analysed in specimens derived from 30 humans, 5 cats and 10 ships. We distinguish the following developmental stages : (i) The arachnoid membrane forms small diverticula that grow toward the superior sagittal sinus. In the majority of cases, this process is followed by an infiltration of mesothelial and connective tissue cells from these diverticula into the dura mater, where it forms the wall of the sinus. (ii) These arachnoid cells form an evagination, giving rise to an arachnoid granulation of simple pediculated form, which, by generating evaginations of second and third order, can become an arachnoid granulation of the so-called complex pediculated form. The wall of the superior sagittal sinus participates in the development of the granulation by the formation of a fibrous capsule. This capsule has openings where arachnoid mesothelium and sinus endothelium are in direct contact.

Animals↗

PubMed1977

Arachnoid diverticula: a unitary approach to spinal cysts communicating with the subarachnoid space.

The authors report six cases of so-called spinal subdural arachnoid cysts, emphasizing the clinical and myelographic findings which, if not properly evaluated, may be misleading diagnostically. The literature of so-called perineural cysts and of extradural arachnoid cysts is likewise reviewed. Their clinical, roentgenological, and pathological features are examined. A common pathogenesis for all these lesions is proposed. It implies disruption and secondary proliferation of the arachnoid membrane. Hence, the term arachnoid diverticulum is advanced to include all lesions communicating with the subarachnoid space. Their varying relations with the subarachnoid space depend on the sites of the primary abnormalities and on hydrodynamic factors. Numerous observations of associated arachnoid diverticula, either perineural, subdural, or extradural, further favour a common pathogenesis.

Adolescent↗

PubMed1979

Results of surgical lysis of lumbar adhesive arachnoiditis.

From a series of 681 patients with lumbar disc disease treated between 1966 and 1978, 17 patients required surgical lysis of lumbar adhesive arachnoiditis, 8 having initially been operated upon by another surgeon. All patients had severe pain as a predominant feature, with pain being bilateral in 9 patients. Pain was the only major symptom in 3; the other 14 exhibited varying combinations of progressive neurological dysfunction. Three patients developed late symptoms after trauma, 8 to 21 years after back surgery. At operation, multisegmental arachnoiditis was found in 5 patients and anular or subtotal adhesions were found in 12. Complete lysis could not be obtained in 4 patients. Fourteen patients were treated with steroids at the time of operation. Follow-up after lysis was less than 1 year for 5 patients but averaged 4.8 years for the remaining 12. During the 1st year after operation, 76% experienced improvement in pain (35%, good to excellent), 71% experienced improvement in neurological status. Follow-up after at least 1 year revealed 50% still enjoying pain relief (25%, good to excellent) and 45% experiencing neurological improvement. Pain relief persisted in 4 of 5 patients followed 5 years or more. The etiological role of myelograpy and lumbar disc surgery in arachnoiditis has probably been over-rated. Arachnoiditis may be symptomatic or asymptomatic and may mask other, treatable lumbar lesions. More frequent intradural exploration for discrepancies between operative and myelographic findings might reveal, and benefit, more cases of spontaneous arachnoiditis mimicking lumbar disc disease.

Adult↗

PubMed1992

Expression of cell adhesion molecule E-cadherin in human arachnoid villi.

Calcium-dependent epithelial cell adhesion molecules designated as E-cadherin (also known as uvomorulin or L-CAM) were identified in human arachnoid villi by immunoblotting and immunocytochemical analyses using a monoclonal antibody HECD-1 raised against human mammary carcinoma MCF-7 cells. Immunoblot analysis showed that HECD-1 recognizes E-cadherin with a molecular weight of 124 kD. In all arachnoid cells of an arachnoid villus, E-cadherin was detected by immunolight microscopy within the cytoplasm rather than the cellular boundaries as seen in the control group. Furthermore, the extent of expression by immunolight microscopy varied from portion to portion. The expression was usually weak in the syncytial cluster which was ultrastructurally composed of tightly juxtaposed cells characterized by few extracellular cisterns and numerous cell junctions, while it was intense in the reticular cluster and the surface layer which were ultrastructurally characterized by abundant extracellular cisterns and smaller numbers of cell junctions. The cells of the reticular cluster and the surface layer contained more free ribosomes than those of the syncytial cluster. Immunoelectron microscopy showed that E-cadherin was localized not only to the opposing plasma membranes and the cytoplasm around the free ribosomes or the rough endoplasmic reticulum but also to the extracellular cisterns. As the expression of E-cadherin was closely related to the arachnoid cells adjacent to the cerebrospinal fluid pathway, it is suggested that, instead of the cell junctions, E-cadherin may play an important role in the flexible adhesion of arachnoid cells even in the presence of the cerebrospinal fluid.

Adolescent↗

PubMed1975

Chiasmatic arachnoiditis and empty sella: report and discussion of a case.

The case is presented of a 5-year-old boy with progressive visual loss and physical findings suggestive of pituitary dysfunction. A craniotomy revealed opticochiasmatic arachnoiditis and empty sella. The concomitance of these conditions has not been reported. Both entities are associated with arachnoid cysts or cyst-like swellings of the arachnoid, according to the literature. It is proposed that a primary arachnoid cyst may have displaced the pituitary in the sella resulting in secondary inflammatory responses which affected the chiasm. An alternate, but similar explanation, would involve a perichiasmatic arachnoiditis of unknown cause resulting in cystic invasion of the sella. Rupture of the presumed cyst is believed to have occurred late in the preoperative course, and to have been responsible for aggravation of the symptoms.

Age Factors↗

PubMed1978

The origin of subdural neomembranes. I. Fine structure of the dura-arachnoid interface in man.

A method for the in situ fixation of human meninges for electron microscopic examination is described. It was found that the cranial meninges of humans do not include a subdural space. Instead there is a complex, tight layer of cells, the interface layer, composed in the innermost portion of the dura mater (the dural border cells) and the outermost portion of the arachnoid (the arachnoid barrier layer). The fusion of these components within the interface layer is much more intimate than is either the attachment of the dural border cells to the dura proper or that of the arachnoid barrier layer to the rest of the arachnoid. The fine structural characteristics of these layers are defined. The erroneous macroscopic impression of a subdural space results from an extraordinary lack of cohesion within the dura-arachnoid interface layer conditioned by a) a complete absence of a collagenous reinforcement within this zone, b) the presence of large extracellular cisterns between the dural border cells, and c) a paucity of intercellular contacts within that latter layer. An understanding of the fine structural organization of the interface layer is essential to any consideration of the pathogenesis of subdural lesions: these form within a sheet of torn dural border cells and not within a preexistent tissue compartment.

Arachnoid↗

PubMed1978

The value of radionuclide myelography in the evaluation of spinal arachnoiditis.

On the basis of myelographic findings, spinal adhesive arachnoiditis was classified into three types: type I (peripheral or marginal), type II (central), and type III (advanced). Depending on its location and extent, it may be divided into group A (lumbar), group B (thoracic), and group C (cervical). In view of the fact that intrathecal injection both of oily and of water-soluble contrast media tends to produce spinal arachnoiditis, we have been using radionuclides for pre- and postoperative myelography to evaluate arachnoiditis. Radionuclide myelography with 131I-HSA or 111In-DTPA is a safe modality which provides useful information regarding spinal arachnoiditis.

Adult↗

PubMed1979

Fine structure of arachnoid cysts.

Recent studies of the fine structure of the cranial meninges of laboratory animals and man have shown that there is no subdural space. The latter is formed artificially by the tendency of meningeal tissues to cleave along a collagen-free zone, the dura-arachnoid interface layer. This layer is composed of an outer zone of dural border cells and an inner arachnoid barrier layer. The fine structure of nine arachnoid cysts was studied to determine the derivation of the cyst's wall from the various components of normal human meninges. A cleaved dura-arachnoid interface layer covered only the dome of the cyst where the latter had abutted the dura mater. The interface layer did not partake in forming the cyst's wall. The dominant phenomenon of the cyst's wall was an absence of the normal trabeculation of the subarachnoid space, the trabecules being replaced by tightly packed collagen fibrils and a few scattered cells in between. Some cells were layered discontinuously at the inner face of the cyst wall, but there was no organized inner lining. No evidence was found for either a tight sealing of the extracellular spaces in the cyst's wall, nor for the existence of an active transcellular fluid movement.

Aged↗

PubMed1978

Adhesive arachnoiditis following lumbar myelography.

Late sequelae (adhesive arachnoiditis) have been reported following myelography with the oily contrast medium (Pantopaque) and with the ionic water-soluble contrast media methiodal sodium (Abrodil, Conturex, Kontrast U) meglumine iothalamate (Conray Meglumine) and meglumine iocarmate (Bis-Conray, Dimer-X). Adhesive arachnoiditis has not yet been reported after the use of the nonionic water-soluble contrast medium metrizamide (Amipaque). Thus, this is considered the contrast medium of choice for lumbar myelography. Using the recommended dose of 10 ml with an iodine concentration of 170 mg/ml for this examination, adhesive arachnoiditis is unlikely to occur. Increased osmolality of spinal fluid after injection of contrast medium is related to increased frequency of arachnoiditis.

Arachnoiditis↗

PubMed1977

Experimental production of arachnoiditis with water-soluble myelographic media.

After myelography with either metrizamide (300mg l/ml) or meglumine iocarmate (280 mg l/ml), mild to severe arachnoid fibrosis was demonstrated radiographically and histologically in primates. Intrathecal injections of metrizamide (170 mg l/ml) or autologous cerebrospinal fluid produced less arachnoiditis. The risk of arachnoiditis is probably minimized by the use of reduced volumes and concentrations of water-soluble media. Controlled studies of arachnoiditis following myelography are probably more reliable in the primate model than in other experimental animals.

Animals↗

PubMed1977

Arachnoiditis following myelography with water-soluble agents. The role of contrast medium osmolality.

The role of contrast medium osmolality in postmyelographic arachnoiditis was studied. Monkeys were injected intrathecally with isotonic saline (290 mOs/kg), hypertonic saline (1,449 mOs/kg), metrizamide (456 or 300 mOs/kg), or methylglucamine iocarnate (1,049 mOs/kg). After 12 weeks the animals were examined for evidence of arachnoiditis, with myelography just prior to sacrifice and microscopic examination of the excised dural sac and its contents. Intrathecal injections of methyglucamine iocarmate or metrizamide caused arachnoiditis while saline did not. Only one animal given 170 mg l/ml (300 mOs/kg) exhibited a more severe reaction than the controls. An increase in the cerebrospinal fluid osmolality alone does not cause arachnoiditis.

Animals↗

PubMed1992

How frequent is chronic lumbar arachnoiditis following intrathecal Myodil?

Chronic lumbar arachnoiditis has numerous causes, including the introduction of contrast media into the lumbar subarachnoid space. The oily contrast medium Myodil (iophendylate) is often cited but the true incidence of symptomatic lumbar arachnoiditis due solely to the presence of Myodil is unknown. A retrospective review of 98 patients in whom Myodil was introduced by ventriculography or cisternography, i.e. remote from the lumbar spine, revealed no cases of chronic lumbar arachnoiditis. All patients were monitored closely for periods ranging from 1 to 28 years. We conclude that, in these circumstances, it is rare for Myodil to produce symptomatic arachnoiditis.

Adult↗