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PubMed1997

Syringomyelia developing as an acute complication of tuberculous meningitis.

BACKGROUND: Tuberculosis of the nervous system has protean manifestations. Syringomyelia, though an uncommon complication of it, is usually of late onset. METHODS: We report two patients with tuberculosis meningitis who developed syringomyelia acutely. The diagnosis was supported by neuroimaging and findings at laminectomy. RESULTS: The two patients developed syringomyelia between 11 days and 6 weeks of the onset of tuberculous meningitis. They both had cord swelling and softening. CONCLUSIONS: Acute-onset syringomyelia should be suspected in any patient being treated for tuberculosis meningitis who subsequently develops limb weakness and/or sphincteric dysfunction. Inflammatory edema and cord ischemia appeared to be the underlying mechanisms in these early onset cases rather than arachnoiditis which is important in late-onset cases.

Acute Disease↗
PubMed2000

Ocular manifestations of hindbrain-related syringomyelia and outcome following craniovertebral decompression.

PURPOSE: To analyse and evaluate associated ocular symptoms and signs in hindbrain-related syringomyelia and their response to treatment. METHODS: From a database of 275 patients treated in a single institution for hindbrain hernia and syringomyelia, 39 patients (14%) had ocular symptoms and signs. Only 31 patients were included in this study; the remainder were excluded due to inadequate follow-up information. All patients had confirmed evidence of hindbrain-related syringomyelia with MRI scan or CT myelogram. Treatment included craniovertebral decompression or ventriculo-peritoneal shunting. The mean follow-up was 23 months. RESULTS: In addition to the well-recognised sign of downbeat nystagmus, classically associated with foramen magnum abnormalities, a number of other ophthalmic features were identified. Symptoms included diplopia, oscillopsia, tunnel vision and difficulty in lateral gaze. Signs included nystagmus (downbeat, horizontal, rotatory, and combinations), strabismus, disc pallor, anisocoria, ptosis and field defect. Patients were categorised into two groups depending on whether the ocular features were manifest at first presentation (group 1, n = 14) or developed later in the course of the disease (group 2, n = 17). The delay in diagnosis from first presentation was 5 and 6 years respectively. All patients underwent surgery. Craniovertebral decompression was performed in 13 patients in group 1 and in 15 patients in group 2. Ventriculo-peritoneal shunt was inserted in 1 patient in group 1 and in 3 patients in group 2, for the associated hydrocephalus. Following surgery, 100% of patients in group 1 and 82% of patients in group 2 had complete or partial resolution of their ocular symptoms and signs. CONCLUSIONS: The presence of unexplained ophthalmic features such as nystagmus or oscillopsia should alert one to the potential diagnosis of hindbrain-related syringomyelia. Delay in diagnosis is often associated with poorer outcome. Surgical treatment can offer excellent results for these patients.

Adolescent↗
PubMed2000

Syringomyelia presenting as a delayed complication of treatment for nocardia brain abscess.

OBJECTIVE: Syringomyelia is defined as a dilatation of the central canal of the spinal cord which often leads to neurologic impairment. Syringomyelia has not previously been reported as a late complication for the treatment of brain abscess. In this report, we review a case involving this unusual association. CLINICAL PRESENTATION: A 25 year-old woman sustained a nocardia brain abscess initially presenting as a pulmonary infection. Treatment led to the development of multiloculated hydrocephalus and syringomyelia. INTERVENTION: Treatment included placement of multiple ventriculoperitoneal shunts and a syringo-pleural shunt. This resulted in stabilization of neurologic symptoms. CONCLUSION: The possibility of developing syringomyelia should be considered in any case involving post-infectious hydrocephalus.

Adult↗
PubMed2005

Foramen magnum decompression for the treatment of Arnold Chiari malformation type I with associated syringomyelia in an elderly patient.

STUDY DESIGN: Report of a rare case of an elderly patient with late onset of Arnold Chiari malformation type I with associated syringomyelia that was successfully treated with foramen magnum decompression. OBJECTIVE: To report this rare case along with a literature review. SETTING: Gifu, Japan. METHODS: A 69-year-old woman with a 4-year history of dull pain in her right arm was referred to the clinic. After physical and radiographical examinations, she was diagnosed with Arnold Chiari malformation type I with associated syringomyelia. A foramen magnum decompression by the removal of the outer layer of the dura mater was performed. RESULTS: At 2 years postoperatively, MRI revealed a decrease in the size of the syringomyelia. Her symptoms had also remarkably improved. CONCLUSIONS: A rare case of symptomatic Arnold Chiari malformation type I with associated syringomyelia in an elderly woman was successfully treated with foramen magnum decompression by the removal of the outer layer of the dura mater.

Aged↗
PubMed2002

Maternal Arnold-Chiari type I malformation and syringomyelia: a labor management dilemma.

Arnold-Chiari type I malformations consists of elongation of the cerebellar tonsils with their displacement below the foramen magnum. Syringomyelia is an associated cyst that accumulates cerebrospinal fluid in the cord that can impinge on local nerve fibers. Pregnant women with either of these disorders are of special concern due to the potential risk of brain stem herniation and or spinal column compression from physiological changes that occur during labor. We present two cases. The first case is a patient with syringomyelia who was admitted in labor with worsening peripheral neurological symptoms. Epidural anesthesia was placed and she underwent an uncomplicated cesarean delivery with resolution of her symptoms postpartum. The second case is a patient with an Arnold-Chiari type I malformation and syringomyelia who presented in labor. The patient had an epidural placed and was allowed to progress to complete dilation and effacement at +2 station. She underwent a successful operative vaginal delivery without voluntary maternal expulsive efforts. Both patients had uncomplicated postpartum courses. Although these are rare disorders with significant potential morbidity, labor can be managed by either mode of delivery with careful patient selection. We caution that this review has insufficient numbers of patients to address the safety and efficacy of either delivery mode but rather focuses on alternatives for delivery. This report is the first to document a case of a patient with an Arnold-Chiari malformation and syringomyelia successfully managed in labor with a vaginal delivery.

Adult↗
PubMed1984

[Diagnostic value of clinical study methods in syringomyelia].

Between 1968 and 1981 52 patients with syringomyelia were investigated clinically and with several additional procedures. The introduction of computerized axial tomography (CAT) has led to a change in diagnostic measurements in this disease. Therefore it has become necessary to evaluate the usefulness of additional investigations made in recent past. From own experiences the following measurements are indicated in patients with presumed syringomyelia: X-rays of the cervical and thoracal spinal column and the skull have to be complemented by automatic computerized transverse axial tomography (ACTA) of the spinal canal. CSF should be investigated before metrizamide myelography combined with computerized tomography--the so called computed assisted myelography--is done. These methods both the automatic computerized transverse axial tomography of the spinal canal and the computed assisted myelography allow a differentiation between communicating and non communicating syringomyelia. Computerized axial tomography of the skull is indicated to detect interval hydrocephalus that may be associated with communicating syringomyelia. The other methods evaluated in this study cannot be used to ascertain diagnosis. These measurements combined with clinical and radiological findings may only support diagnosis. Their significance lies in the critical examination of lost functions in the individual case. Especially electrodiagnostic test--as electromyelography and measurement of nerve conduction velocity--show the extension and distribution of the involved peripheral nervous system. These methods are necessary for the critical evaluation of both the spontaneous clinical course and the results of therapeutic procedures. The electromyography findings show the process of denervation already occurred and the degree of motor activity yet available. The measurement of nerve conduction velocity indicates the localization of involved peripheral nerves. The determination of evoked potentials yields informative findings. But at present the value of this method cannot yet be estimated finally. The indication of the discussed investigations depends on the clinical findings in the individual case with the exception of the radiological procedures.

Adult↗
PubMed1986

Progress in syringomyelia.

Syringomyelia management is showing some progressive improvements following surgical methods of investigation and treatment. Investigation of simultaneous pressure changes in the cerebrospinal fluid pathways has illustrated the importance of craniospinal pressure dissociation in impacting the cerebellar and medullary tissues in the foramen magnum in hindbrain related syringomyelia. Such pressure differences may be referred to as 'suck' and similar changes are to be found in non-hindbrain related forms of syringomyelia such as those associated with spinal arachnoiditis. When cavities have formed then impulsive movements may occur with them and enlargement of the cavities may be continued by sloshing of the fluid within them. Investigations have been improved following the widespread use of water soluble contrast media and CT scanning with reconstructions after myelography. A definite relationship between birth injury and hindbrain related syringomyelia has been established especially with cases showing arachnoiditis. The nature of the relationship to hindbrain hernia and basilar invagination remains unclear. Magnetic resonance imaging holds great promise particularly in showing hindbrain deformation in new-born babies, showing whether or not a communication commonly exists between the fourth ventricle and the cavities within the spinal cord in early childhood and also in outlining the changes in the spinal cord in the presence of acute traumatic paraplegia. Treatment still relies upon valved ventricular to extrathecal shunts for hydrocephalus, cranio-vertebral decompression to prevent suck and drainage of the syrinx in appropriate cases. Syrinx to extrathecal shunting may be preferred to shunts to the subarachnoid space. The peritoneum and the pleura are favoured sites and a valve is not necessary. The advances for the future may depend on earlier diagnosis and greater understanding of the mechanisms of pathogenesis in which MRI seems likely to play an increasingly important part.

Arnold-Chiari Malformation↗
PubMed1991

Surgical management of syringomyelia: a five year experience in the era of magnetic resonance imaging.

We summarize our experience with 59 consecutive surgically managed cases of syringomyelia (SM) over a 5 year period. All cases had magnetic resonance imaging (MRI) preoperatively and postoperatively. Twenty-eight patients presented with SM and the adult Chiari (Chiari I) malformation (SM-ACM), 6 patients had post traumatic syrinxes, 14 patients had syrinxes associated with an intramedullary neoplasm, 3 patients had syringomyelia associated with spinal arachnoiditis and 8 patients had idiopathic syringomyelia. Holocord syrinxes were more often associated with SM-ACM, while focal syrinxes were associated with posttraumatic, spinal arachnoiditis and neoplastic conditions. In all cases with neoplasms the MRI revealed parenchymal intramedullary signal abnormalities in addition to the syrinx cavity. Posterior fossa decompression with obex plugging (the Gardner operation) was the procedure of choice for SM-ACM and for idiopathic holocord syringomyelia. Exploration and drainage of the syrinx with or without shunting was carried out mainly for focal syrinxes associated with trauma and neoplasm. Patients with SM-ACM responded well to posterior fossa decompression with satisfactory results in 24/28 patients. Idiopathic SM is probably a forme fruste of SM-ACM and when treated with the Gardner procedure showed good results in all 8 patients. Posttraumatic and neoplastic SM had the least predictable results with surgery. The disappearance of the syrinx on postoperative MRI correlated well with a good surgical outcome.

Adolescent↗
PubMed1999

Intra-operative spinal cord neuromonitoring in patients operated on for intramedullary tumors and syringomyelia.

Intra-operative neuromonitoring is of great help to the neurosurgeon and enables him to operate more precisely and with less risk of post-operative neurological deficit. The purpose of the study was to define the changes of the somatosensory evoked potentials (SEP) elements in intramedullary tumors and syringomyelia, and to show the correlation between the changes of the elements and the location of the lesions in the spinal cord. Thirty patients with pain syndromes, intramedullary tumors and syringomyelia were operated on the spinal cord. The methodology of the intra-operative neuromonitoring was based on electrical stimulation of peripheral mixed nerve (tibial and median), and on intra-operative subpial recording of conducted and interneuronic SEP from the dorsal surface of the spinal cord. The recordings in pain syndrome cases were normal, and were compared with recordings obtained in syringomyelia and tumors. The most stable element of the conducted SEP are the initial negative waves that originate in the spinocerebellar tract. Deterioration of the negative high amplitude potentials is the most sensitive indicator of damage to the somatosensory system of the spinal cord, and indicates damage to the dorsal columns. The N11 and N14 waves are the most stable elements of the cervical and lumbosacral interneuronic SEP, and most probably originate in the dorsal root entry zone. Changes of the N13 and N17 elements of interneuronic SEP suggest damage to the spinal cord gray matter, and are most frequently changed in intramedullary lesions. High frequency waves seen on N13 or N17 probably reflect the somatosensory long tracts, and are even better seen in syringomyelia and pure intramedullary tumors. Changes in the elements of interneuronic and conductive SEP enable us to localize the anatomical site of the lesion, which is of great help to the operating neurosurgeon.

Adolescent↗
PubMed2006

Symptomatic syringomyelia secondary to clinically obscure infratentorial tumour.

The formation of a cervical spinal cord syrinx as a result of an infratentorial mass, even though uncommon, has been reported in international literature. In such cases, syringomyelia is usually asymptomatic, while the tumour-related symptoms and signs predominate. We report a patient with a posterior fossa tumour and secondary syringomyelia. In this patient, syringomyelia symptoms and signs were present, and a cervical spine Magnetic Resonance Imaging (MRI) showed a large cervical syrinx. A more careful clinical examination though, revealed a sub-clinical posterior fossa syndrome and brain MRI revealed a large infratentorial meningioma. A posterior fossa craniotomy was performed, followed by complete tumour resection and almost complete remission of the syrinx and its related symptoms. The authors discuss the role of posterior fossa tumour induced tonsillar herniation in the development of secondary syringomyelia, the mechanisms leading to syrinx formation and the conditions that must be fulfilled for that to happen.

Female↗
PubMed1997

Idiopathic syringomyelia and the importance of occult arachnoid webs, pouches and cysts.

Syringomyelia is the condition in which longitudinal cavities are found within the spinal cord. The use of drainage procedures has been widely practised with good short term results. However, the long-term results in some large series have been less favourable. There are many associated conditions and in most forms a blockage to the normal flow of CSF, either at the foramen magnum or in the spinal canal, can be identified. Most surgeons would now direct their efforts to the establishment of normal CSF flow rather than a shunting procedure. In a certain group of patients, even with the advent of sophisticated MRI, no associated abnormality or CSF block is easily identified. This type of syringomyelia is often termed idiopathic. We report 10 patients with symptomatic syringomyelia without readily recognized predisposing factors. In eight patients preoperative myelography revealed a block to the flow of contrast compatible with subarachnoid obstruction. Eight patients underwent laminectomy and division of the obstructing arachnoid webs. Five experienced good improvement and three only moderate improvement. Two of the patients underwent syrinx shunting procedures only, which resulted in a worsening of their symptoms. At operation one patient was found to have an arachnoid cyst. We believe that patients with idiopathic symptomatic syringomyelia may need myelography to identify such arachnoid abnormalities. Subsequent surgery should be directed at the establishment of normal CSF flow by laminectomy and excision of the offending lesion.

Adult↗
PubMedDate not supplied

CT-guided percutaneous drainage of syringomyelia.

PURPOSE: Our purpose is to describe CT-guided percutaneous drainage of syringomyelia as a possible contribution in patient management. METHOD: CT-guided percutaneous drainage was performed on three patients with symptomatic syringomyelia. We determined the success of percutaneous decompression by subsequent CT and MRI. The effect of syringomyelia decompression in relation to the patient's symptoms was determined. This information was then used to help guide clinical management. RESULTS: In Case 1, percutaneous drainage of a large syrinx in a C5 quadriplegic patient with increasing lower extremity spasticity demonstrated significant decompression by imaging but did not result in clinical improvement. A surgical procedure to decompress the syrinx was not performed on the basis of this information. In Case 2, percutaneous drainage of a large syrinx in a quadriplegic patient with increasing upper extremity numbness and weakness demonstrated significant decompression by imaging and resulted in sustained clinical improvement, temporarily obviating the need for surgery. In Case 3, percutaneous drainage of the rostral aspect of a septated syrinx cavity in a patient with a Chiari I malformation and a syringoperitoneal shunt in place resulted in decompression by imaging but failed to relieve the patient's newly developed symptoms. An additional shunt was therefore not placed. In no case did the patient experience periprocedural complications or worsening of symptoms. CONCLUSION: CT-guided percutaneous drainage of syringomyelia is a safe and successful technique. It can be used diagnostically to identify patients that may or may not benefit from surgical syrinx decompression and in some cases may provide a temporary therapeutic alternative to surgery.

Adolescent↗
PubMed1996

Dysesthetic pain in patients with syringomyelia.

Dysesthethic pain is a common complaint of patients with syringomyelia, traumatic paraplegia, and various myelopathic conditions. Because cavitary lesions of the spinal cord can be defined with good resolution by magnetic resonance imaging, syringomyelia provides a potential model for examining anatomic correlates of central pain. In this study, a syndrome of segmental dysesthesias, characterized by burning pain, hyperesthesia, and a variable incidence of trophic changes, was described by 51 of 137 patients (37%) with syringomyelia at the time of clinical presentation. Complete magnetic resonance scans, including axial images, demonstrated extension of the syrinx into the dorsolateral quadrant of the spinal cord on the same side and at the level of pain in 43 of 51 patients (84%). Surgical treatment of syringomyelia resulted in the relief or improvement of dysesthetic pain in 22 of 37 patients (59%), but 15 patients (41%) reported no improvement or an intensification of pain despite collapse of the syrinx. Postoperative dysesthetic pain was often a disabling complaint that responded poorly to medical therapy, including analgesics, sedatives, antiepileptics, antispasmodics, and anti-inflammatory agents. In most cases, there was a gradual improvement of symptoms, although six patients continued to complain of pain 24 to 74 months postoperatively. Prompt but transient relief was achieved in two of two patients with regional sympathetic blocks, and prolonged relief was achieved in one patient by stellate ganglionectomy. We conclude that painful dysesthesias can be caused by a disturbance of pain-modulating centers in the dorsolateral quadrant of the spinal cord and have certain causalgia-like features that respond in an unpredictable way to surgical collapse of the syrinx.

Adolescent↗
PubMed1999

Cerebrospinal fluid flow in an animal model of noncommunicating syringomyelia.

OBJECTIVE: The source of fluid and the mechanism of cyst enlargement in syringomyelia are unknown. It has been demonstrated that cerebrospinal fluid (CSF) normally flows from the subarachnoid space through perivascular spaces and into the spinal cord central canal. The aim of this study was to investigate whether this flow continues during cyst formation in an animal model of syringomyelia and to determine the role of subarachnoid CSF flow in this model. METHODS: The intraparenchymal kaolin model of noncommunicating syringomyelia was established in 78 Sprague-Dawley rats. Horseradish peroxidase was used as a tracer to study CSF flow at 1 day, 3 days, 1 week, and 6 weeks after kaolin injection. CSF flow was studied at 0, 10, and 30 minutes after horseradish peroxidase injection into the cisterna magna or thoracic subarachnoid space. RESULTS: The central canal became occluded at the level of the kaolin injection and at one or more rostral levels. Segments of the central canal isolated between occlusions gradually dilated, and axonal retraction balls were detected in the surrounding white matter. There was a partial blockage of subarachnoid CSF flow at the site of the kaolin injection, both in a rostral-caudal direction and in a caudal-rostral direction. Horseradish peroxidase was detected at all time points, in a distinctive pattern, in perivascular spaces and the central canal. This pattern was seen even where segments of the central canal were isolated and dilated. CONCLUSION: In this animal model, noncommunicating syringes continue to enlarge even when there is evidence that they are under high pressure. There may be an increase in pulse pressure rostral to the block of subarachnoid CSF flow, causing an increase in perivascular flow and contributing to syrinx formation. The source of fluid in noncommunicating syringomyelia may be arterial pulsation-dependent CSF flow from perivascular spaces into the central canal.

Animals↗
PubMed2000

Resolution of tonsillar herniation and syringomyelia after supratentorial tumor resection: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: The pathophysiological features of syringomyelia are not yet entirely understood. We present a case of a supratentorial mass causing tonsillar herniation and syringomyelia. CLINICAL PRESENTATION: A 51-year-old woman underwent magnetic resonance imaging for evaluation of progressive headaches. A large parieto-occipital mass was revealed. Herniation of the cerebellar tonsils and a cervical syrinx were also noted. INTERVENTION: A craniotomy was performed without incident. After tumor resection, the tonsils ascended and the syrinx resolved in a 1-year period. CONCLUSION: This case highlights the importance of tonsillar herniation in the pathogenesis of syringomyelia. "Acquired" Chiari malformations and syringomyelia attributable to supratentorial masses may be treated by mass resection alone, without the need for foramen magnum decompression.

Female↗
PubMed2001

Excitotoxic model of post-traumatic syringomyelia in the rat.

STUDY DESIGN: A rat model was developed to elucidate the role of excitatory amino acids and spinal subarachnoid block in the genesis of post-traumatic syringomyelia. This excitotoxic model produces intramedullary cavities rather than the dilation of the central canal (canalicular syringomyelia) created by previous animal models. OBJECTIVES: To produce extracanalicular cysts in the rat spinal cord with quisqualic acid, a potent agonist of multiple excitatory amino acid receptors, and to compare the effects of excitotoxic injury only with that of excitotoxic injury and subarachnoid block with kaolin. SUMMARY OF BACKGROUND DATA: In post-traumatic syringomyelia, primary injury and excitotoxic cell death secondary to elevated levels of excitatory amino acids may initiate a pathologic process leading to the formation of spinal cavities. Subarachnoid block by arachnoiditis may promote enlargement of the cavities. METHODS: Three control rats received a unilateral injection of normal saline into the spinal cord, and another five rats received an injection of kaolin into the spinal subarachnoid space. Quisqualic acid was injected unilaterally into the spinal cord of 20 rats, and 13 additional rats received a unilateral injection of quisqualic acid into the spinal cord after injection of kaolin into the subarachnoid space. Histologic and immunocytochemical assessments were undertaken. RESULTS: In the control groups, no parenchymal cyst developed in any of the animals. Spinal cord cyst formation was observed in 16 of 19 animals in the quisqualic acid groups, but no cysts exceeding two segments in the length of the spinal cord developed in any of the rats. Much larger cavities were seen in 9 of 11 animals in the group with quisqualic acid and kaolin, and cysts exceeding two segments developed in all 9 of these (9/11; 82%). CONCLUSIONS: In post-traumatic syringomyelia, excitotoxic cell death occurring secondarily to elevated levels of excitatory amino acids may contribute to the pathologic process leading to the formation of spinal cord cysts. Subarachnoid block by arachnoiditis is likely to cause enlargement of the cavity.

Animals↗
PubMed2003

Scoliosis associated with syringomyelia: clinical and radiologic correlation.

STUDY DESIGN: A retrospective review with statistical correlations of 112 patients having both scoliosis and syringomyelia was performed. OBJECTIVE: To determine whether there were significant correlations between the type of scoliosis, location of the syrinx, size of the syrinx, clinical manifestation of the syrinx, and associated lesions such as cord tethering and Chiari malformation (Chiari I or Arnold-Chiari II). SUMMARY OF BACKGROUND DATA: The coexistence of scoliosis and syringomyelia has been described previously, but these detailed correlations have had minimal attention. METHODS: All patients at the center with scoliosis of any type plus a syrinx had a detailed chart and radiologic review coupled with detailed statistical analysis. RESULTS: Scoliosis and syringomyelia were seen in four diagnoses: myelomeningocele, myelomeningocele with congenital scoliosis, congenital scoliosis, and scoliosis with neither congenital anomalies nor myelomeningocele. Chiari malformation and cord tethering appear to have a major relation to scoliosis with syringomyelia. CONCLUSIONS: Anomalies of the spinal cord or spinal column coexisting with lesions of the central nervous system have significant effects on the syrinx and scoliosis. There is a significant relation between the most caudal level of the syrinx and the locations of the scoliosis.

Abnormalities, Multiple↗
PubMed2005

Origin of macrophages in a kaolin-induced model of rat syringomyelia: a study using radiation bone marrow chimeras.

STUDY DESIGN: Animal experimental study. OBJECTIVE: To study the origin of macrophages in a rat model of syringomyelia. SUMMARY OF BACKGROUND DATA: Syringomyelia is a clinically important condition in which a cystic cavity forms within the spinal cord. This leads to significant delayed neurologic deterioration, which may be manifested as weakness, numbness, or pain. The pathophysiology and mechanism of syrinx formation remain unclear. Human autopsy findings have demonstrated a prominent accumulation of macrophages in relation to the syrinx. Similar observations have also been made in a previously established rat model of syringomyelia. Little is known about the origin and precise functions of these cells. METHODS: Syrinx formation was induced by intraparenchymal injections of kaolin within the cervical spinal cords of 30 DA rat (RT7.1) radiation bone marrow chimeras reconstituted with bone marrow from RT7.2 congeneic donors. The distribution of macrophages was evaluated at survival times of 3 days, 1 week, and 4 weeks. Immunostaining of fresh-frozen spinal cord tissue was performed using specific antibodies against rat macrophage ED1 antigen and RT7.2 allele of CD45. This allowed donor-derived hematogenous (ED1+, RT7.2+) macrophages to be distinguished from native cells (ED1+, RT7.2-). RESULTS: Central canal dilatation was seen from 1 week. This was associated with extensive accumulation of ED1+ macrophages within the spinal cord parenchyma. A large influx of bone marrow-derived (ED1+, RT7.2+) macrophages was observed. However, a considerable proportion of resident microglia (RT7.2-) also upregulated ED1. These activated microglia demonstrated distinct morphologic features. CONCLUSIONS: Large numbers of macrophages were recruited from the bone marrow in kaolin-induced rat syringomyelia. However, a significant number of resident microglia upregulated their ED1 activity and appear to provide a substantial source of macrophages.

Animals↗