Syringo-subarachnoid shunt for syringomyelia associated with Chiari malformation (type 1)

Summary The authors report the surgical results of 28 patients with syringomyelia associated with Chiari malformation (type 1). 28 patients underwent 34 operative procedures. Syringo-subarachnoid shunt was performed in 28 patients, foramen magnum decompression with syringo-subarachnoid shunt in three, ventriculo-peritoneal shunt in one, terminal syringostomy in one, and foramen magnum decompression with terminal syringostomy in one. In an average postoperative follow-up period of 3 years and 9 months ranging from one year to 7 years and one month, neurological symptoms and signs improved in 24 out of 28 patients (82%). Some improvement was noted in sensory deficit and motor weakness. In 3 patients, the symptoms did not change. In 3 patients whose symptoms were unchanged, preoperative studies demonstrated atrophy of the spinal cord, in which irreversible changes were shown. The symptoms deteriorated in one patient. In one patient whose symptoms increased 3 months after syringo-subarachnoid shunt, shunt insufficiency due to postoperative adhesive arachnoiditis was responsible for neurological deterioration.The authors propose that syringo-subarachnoid shunt is effective as a surgical procedure for syringomyelia associated with Chiari malformation (type 1) if the patient does not have symptoms due to Chiari malformation or has only mild signs and symptoms which do not require foramen magnum decompression, such as nystagmus or atrophy of sternocleidomastoid muscle.     

Hydrosyringomyelia associated with a Chiari I malformation in children and adolescents

The clinical presentation, radiological features, and results of surgical treatment were analyzed in 17 cases of hydrosyringomyelia associated with a Chiari malformation, in children and adolescents younger than 20 years of age. The initial symptoms were a skeletal abnormality (71%), such as scoliosis (11 patients) or pes cavus (1 patient), pain or numbness (24%), and motor weakness (6%). Frequently seen signs on admission were sensory deficit (100%), scoliosis (85%), muscle weakness (64%), muscle atrophy (35%), and lower cranial nerve palsy (35%). The characteristic neurological findings were unilateral sensory and motor deficits (65%) with decreased or absent deep tendon reflexes on the same side. The localization of the syrinx on the axial section varied according to the level, even in the same patient. In 11 patients with unilateral sensory disturbances or unilateral sensory and motor deficits, the syrinx was located in the region corresponding to the posterolateral portion on the same side as that of sensory disturbance at the cervical or thoracic level. On the other hand, in 6 patients with bilateral sensory and motor deficits, the syrinx was located in the central portion and extended into the posterolateral portion of the more affected side. A syringosubarachnoid shunt was placed in 16 patients, foramen magnum decompression without closure of the obex was performed in 1 patient, ventriculoperitoneal shunt in 1 patient, terminal syringostomy in 1 patient, and foramen magnum decompression with terminal syringostomy in 1 patient. In 15 of 17 patients (88%), the neurological symptoms improved after an average follow-up of 4 years and 1 month. We think that as a surgical treatment, placement of a syringosubarachnoid shunt is effective.     

Diagnosis of a cystic lesion in the spinal cord--studies on delayed CT myelography and MRI

The collection of contrast medium within the spinal cord on delayed CT myelography generally indicates the presence of syringomyelia. We report the cases of cystic myelopathy with intramedullary contrast accumulation on delayed CT myelography. The purpose of this report is to compare MRI with delayed CT myelogram and to discuss the pathogenesis of the intramedullary contrast accumulation on delayed CT myelography. Methods and Materials: Thirty patients with intramedullary contrast accumulation on delayed CT myelography were studied with High Resolution Computed Tomography (Siemens Somatom II) and Magnetic Resonance Imaging (MRI) (0.15T imager, Toshiba MRT 15A). MRI were routinely obtained in both axial plane and sagittal plane. Short spin-echo sequences (30 msec TE, 500 msec TR) were used. This series included 6 cases of cervical disc disease, 5 cases of Chiari malformation, 4 cases of lipomeningocele, 4 cases of adhesive arachnoiditis, 2 cases of thoracolumbar spondylosis, 2 cases of trauma, one case of spinal arachnoid cyst, one case of spinal epidural cyst, and 5 cases of idiopathic type. Results: 1) In 17 out of the 30 patients (57%), the region corresponding to the region of contrast medium collection, which was visualized on delayed CT myelography, was seen as an area of the low signal intensity on MRI. In 11 cases out of 17, the syrinx cavity was confirmed at surgery. 2) In 13 cases, delayed CT myelogram showed collection of intramedullary contrast medium, but MRI failed to reveal an area of low signal intensity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical evidence for cervical myelopathy due to Chiari malformation and spinal stenosis in a non-randomized group of patients with the diagnosis of fibromyalgia

Objective While patients with fibromyalgia report symptoms consistent with cervical myelopathy, a detailed neurological evaluation is not routine. We sought to determine if patients with fibromyalgia manifest objective neurological signs of cervical myelopathy.Methods Two hundred and seventy patients, 18 years and older, who carried the diagnosis of fibromyalgia but who had no previously recognized neurological disease underwent detailed clinical neurological and neuroradiological evaluation for the prevalence of objective evidence of cervical myelopathy and radiological evidence of cerebellar tonsillar herniation (Chiari 1 malformation) or cervical spinal canal stenosis.Results Patients were primarily women (87%), of mean age 44 years, who had been symptomatic for 8 years (standard deviation, 6.3 years). The predominant complaints were neck/back pain (95%), fatigue (95%), exertional fatigue (96%), cognitive impairment (92%), instability of gait (85%), grip weakness (83%), paresthesiae (80%), dizziness (71%) and numbness (69%). Eighty-eight percent of patients reported worsening symptoms with neck extension. The neurological examination was consistent with cervical myelopathy: upper thoracic spinothalamic sensory level (83%), hyperreflexia (64%), inversion of the radial periosteal reflex (57%), positive Romberg sign (28%), ankle clonus (25%), positive Hoffman sign (26%), impaired tandem walk (23%), dysmetria (15%) and dysdiadochokinesia (13%). MRI and contrast-enhanced CT imaging of the cervical spine revealed stenosis. The mean antero-posterior (AP) spinal canal diameter at C2/3, C3/4, C4/5, C5/6, C6/7 and C7/T1 was 13.5 mm, 11.8 mm, 11.5 mm, 10.4 mm, 11.3 mm and 14.5 mm respectively, (CT images). In 46% of patients, the AP spinal diameter at C5/6 measured 10 mm, or less, with the neck positioned in mild extension, i.e., clinically significant spinal canal stenosis. MRI of the brain revealed tonsillar ectopia >5 mm in 20% of patients (mean=7.1±1.8 mm), i.e., Chiari 1 malformation.Conclusion Our findings indicate that some patients who carry the diagnosis of fibromyalgia have both signs and symptoms consistent with cervical myelopathy, most likely resulting from spinal cord compression. We recommend detailed neurological evaluation of patients with fibromyalgia in order to exclude cervical myelopathy, a potentially treatable condition.     

Surgical treatment of late neurological deterioration in children with myelodysplasia

Summary Late deterioration of the neurological condition in patients operated on for myelomeningocele repair has been repeatedly reported in the literature. At the present time magnetic resonance imaging (MRI) allows one to recognize various pathological conditions which can be amenable to surgical correction in these patients, such as Chiari type II malformation, hydro/syringomyelia, decompensated hydrocephalus, and tethered spinal cord.The authors report their experience with 26 myelodysplastic children operated on for myelomeningocele repair in the early neonatal period, who exhibited late deterioration at variable time intervals from the first operation. The children were examined pre-operatively by means of MRI; the results were compared with those provided by MRI in 46 myelodysplastic children who underwent the investigation as a routine follow-up control. The MRI findings were subdivided into 4 main groups of increasing severity from 1 to 4; in some subjects, associated pathological conditions (Chiari II malformation, hydromyelia, etc.) were detected as well.Twenty-two out of the 26 patients with late neurological deterioration were operated on. Eleven of them (grades 2 to 4) underwent detethering of the fixed conus, with an improvement of their clinical picture from mild to good. On the other hand the remaining 11 subjects (grades 1 to 2) improved their condition following the correction of the associated abnormalities (malfunctioning CSF shunt: 5 cases; hydromyelia: 4 cases; symptomatic Chiari II malformation: 2 cases).     

Adult Chiari malformation--five operative cases

Recently, the diagnosis of adult Chiari malformation seems to have easy, because of the development of high resolution CT. During the last two years, we experienced with five cases of adult Chiari malformation diagnosed by CT metrizamide myelography. There were two males and three females aged from 15 to 55 years. Three cases had both foramen magnum compression and cerebellar symptoms. One of them had lower cranial nerve symptoms too. Another case had central cord symptoms, and the rest of them complained only of headache and vertigo. All cases underwent suboccipital craniectomy and upper cervical laminectomy. After operation, the cerebellar symptoms improved remarkably. Some of the central cord symptoms improved too. In one case with headache and vertigo, the result was unsuccessful. All cases were followed up in the outpatient clinic more than one year after operation. One case unchanged. Another case deteriorated seven months after surgery. The other three cases were in good condition. Operated cases of adult Chiari malformation are relatively rare in Japan. However, this type of malformation can be found easily by CT metrizamide myelography. A good many patients should be operated on carefully in consideration of their symptoms and severities.     

Management of hydromyelia

The authors review their experience in the management of 22 patients with hydromyelia over a 26-month period. Ten children had Chiari I malformations and hydromyelia; 4 children had myelomeningoceles (3 with large thoracic spinal cord cavitations and 1 with cervical hydromyelia); 6 children had distal hydromyelia associated with tethered cords and occult dysraphism; and 2 patients had cavitation subsequent to arachnoiditis. All patients were investigated preoperatively with MRI and intraoperatively with ultrasound. These neurodiagnostic examinations dictated the type of surgical intervention. Patients with Chiari I or Chiari II malformations, cervical hydromyelia, or basal arachnoiditis underwent decompression of the hindbrain malformations, myelotomy with drainage of the cyst, and placement of a stent. When the area of hydromyelia extended to the obex, as demonstrated by intraoperative ultrasound, the obex was plugged. Cyst-pleural shunts were placed in the children who had myelomeningoceles and thoracic hydromyelia. Patients with distal hydromyelia underwent modified terminal ventriculostomy. The classical presentation of brachial amyotrophy and dissociated sensory loss was present in only 3 patients. Progressive scoliosis without neurological deficit, pain, and Lhermitte's phenomenon were common presentations. The patients with tethered cords were generally asymptomatic from their cysts. The authors discuss operative technique, utilization of intraoperative ultrasound, and surgical outcome.     

Computed tomographic metrizamide myelography in Chiari malformation in adult--special reference to the diagnostic values of reconstruction CT

Three adult patients with a clinical diagnosis of Chiari malformation were examined by computed tomography after intrathecal injection of metrizamide via the lumbar route. In all patients Chiari malformation was demonstrated as a soft tissue oval mass at the level of C1-C2 vertebral body that was intradural and posterior to the medulla and the upper cervical spinal cord. These findings were more accurately visualized in saggital and in frontal reconstructed CTs. In one patient the spinal cord was measurably enlarged at the upper thoracic level. A delayed scan was obtained in another case at 24 hours after the injection and the syrinx was remained opacified whereas the density of cerebrospinal fluid and parenchyma decreased. In the third patient no abnormality of the cord was demonstrated either in CT or myelography. High resolution CT, especially reconstruction-CT appears to be more reliable than myelography and should be the examination of choice in the diagnosis of Chiari malformation.     

A Rare Case of Chiari Type-1 Malformation Accompanied by Symptomatic Cerebrospinal Fluid Hypovolemia: Comparison of Congenital Chiari Type-1 Malformation and Acquired Chiari Malformation Secondary to Cerebrospinal Fluid Hypovolemia: Case Report

A 23-year-old woman was injured in a rear-end collision. She had general malaise and posterior neck pain, which were more severe when she was in an upright position. Magnetic resonance imaging (MRI) revealed the presence of cerebellar tonsil descensus and syringomyelia in the spinal cord. Radioisotope (RI) cisternography showed signs of an early accumulation of RI in the bladder, and a delayed accumulation of RI in the cerebral fornix. We considered the possibilities of cerebrospinal fluid (CSF) hypovolemia and congenital Chiari type-1 malformation as being responsible for her headache. To obtain a definitive diagnosis, we performed gadolinium (Gd)-enhanced MR cisternography and found evidence of CSF leakage. We performed an epidural blood patch (EBP), and her symptoms resolved. In 2 years since the episode, her symptoms have not recurred, and additional treatment has not been required. In addition, MRI performed 2 years after the EBP did not reveal any changes. There seems no previous report which described successful differentiation of pre-existing congenital Chiari type-1 malformation from the acquired one caused by symptomatic CSF hypovolemia. Because treatment protocols differ between these two conditions, the establishment of a correct diagnosis is important.     

Spontaneous remission of paralysis due to spinal extradural hematoma: case report

Spontaneous spinal extradural hematoma is an uncommon cause of cord compression and paraplegia. The clinical presentation of this entity is uniform, with sudden pain followed by sensory and motor dysfunction. Unlike other considerations in the differential diagnosis of cord compression, here the pain and clinical deficit may remit suddenly and spontaneously. This feature may obscure the diagnosis of an organic cause for cord dysfunction. This report describes a patient whose extradural hematoma was caused by hemorrhage from an arteriovenous malformation. Dramatic reduction of his pain and paralysis followed myelography.     

Chiari畸形的研究进展

Chiari畸形是以小脑扁桃体下疝畸形为特，止的先天性疾患，目前较为公认的理论是起源于胚胎中胚叶轴旁的枕骨原节发育不良所敏，其诊断主要依赖于MRI。根据解剖上的异常，通常分为4型。临床分型有利于术式的选择，有Pillay、Bindal等分型，但尚无公认的分型。手术是治疗Chiari畸形的唯一有效方法，针对不同病情相位采取后颅窝减压、分流术或减压加分流手术，大部分患者的症状和体征可以得到改善。     

Chiari type 1 malformation and magnetic resonance imaging

The Chiari type 1 malformation is common. Unlike the Chiari type 2 and 3 malformations, it may remain latent for a long time, becoming symptomatic only in adulthood. The introduction of MRI has resulted in an increased number of diagnoses of this malformation in pediatric patients. It appears to be related to underdevelopment of the posterior cranial fossa. It must be differentiated from acquired tonsillar herniation, particularly when herniation results from intracranial hypotension; these cases are sometimes reported as acquired Chiari I malformation with spontaneous resolution. Tonsillar ectopia may cause symptoms by its direct effect on any or all of the medulla and the cerebellar and upper spinal cord. The most suggestive of the oculomotor disturbances is oscillopsia with downbeat nystagmus. Dysphonia and dysphagia are common. Potentially serious autonomic disturbances are also frequent: sleep apnea, respiratory failure, syncope and even sudden death. Another risk is syrinx formation, resulting from obstruction of CSF circulation in the cisterna magna. Syringomyelia is detected in 32 to 74% of patients with Chiari I malformation. Treatment is surgical. Posterior fossa decompression is achieved by suboccipital craniectomy combined with laminectomy of the upper cervical segments. Surgical intervention is indicated when the malformation is symptomatic and there is no doubt that it is the cause of the symptoms. When a Chiari I malformation is identified fortuitously on MRI, long-term monitoring is essential. The risk of developing symptoms increases over time. Patients should be advised not to participate in contact sports.     

Hidden aqueductal stenosis associated to bilateral idiopathic foramina of Monro stenosis mimicking a Chiari I malformation? Case report

A 39-year old man came to our outpatient clinic with long history of unspecific symptoms and signs. Cerebral MRI showed herniation of the cerebellar tonsils of more than 1?cm below the foramen magnum and a triventricular hydrocephalus. A diagnosis of Chiari I malformation was retained. After an osteo-dural decompression of the posterior fossa, post-operative MRI revealed an aqueductal stenosis with triventricular hydrocephalus. An endoscopic-third- ventriculostomy showed an idiopathic stenosis of the right foramen of Monro. Residual symptoms and persistence of biventricular hydrocephalus justified a ventriculo-peritoneal shunt. Aqueductal and foramina of Monro stenosis can mimick a Chiari I malformation.     

Presentation and management of pediatric Chiari malformations without myelodysplasia

Chiari malformations without myelodysplasia are rarely diagnosed in the pediatric age group. With current neurodiagnostic techniques, however, they are being seen more frequently. Unfortunately, the prognosis is not clear because publications have included a number of different entities, used a variety of surgical approaches, and lacked long term follow-up. Sixteen patients younger than 20 years were treated for Chiari malformations (without myelodysplasia) between 1975 and 1985. The average age was 11 years, and the average duration of symptoms was 20 months. The common symptoms were isolated motor weakness (56%), pain (37.5%), and sensory loss (25%). Frequently seen signs were motor deficit (81%), sensory loss (50%), scoliosis (50%), and cranial nerve palsy (50%). The surgical procedures used were foramen magnum decompression (3 transoral clivus odontoid resections and 15 posterior fossa decompressions with dural grafting), alteration of cerebrospinal fluid (CSF) pathways at the cervicomedullary junction (plugging the foramen cecum and a 4th ventricle to subarachnoid shunt with posterior fossa decompression), and ventriculoperitoneal shunting (2 cases). In follow-up, 37.5% of the patients are asymptomatic, 50% are improved, and 12.5% are stable after an average follow-up period of 43 months. The asymptomatic group was younger (9.3 years) and had a shorter symptom duration (7.2 months) than both the improved (11.9 years, 16.4 months) and the stable groups (15 years, 20 months). Optimal outcome depends on complete evaluation of the abnormal CSF pathways and bony abnormalities at the craniovertebral junction. Operation is then directed toward correction of these abnormalities as delineated radiographically. Of our patients, 87.5% have at least shown improvement, which has been long term in all cases.     

Wirbelsäulenerkrankungen und assoziierte ZNS-Fehlbildungen – Tethered-Cord und Arnold-Chiari-Fehlbildung

Tethered cord syndrome (TCS) and the Chiari malformation (CM) are generally related to congenital malformations, but both entities can be acquired.TCS often presents with progressing sensory and motor symptoms that can be attributed to increased tension of the spinal cord. Fixation of the spinal cord can occur congenitally (primary TCS) or in association with other intraspinal pathologies or postoperative scarring (secondary TCS). Exact diagnosis in the adult can be difficult if symptoms are interpreted as being related to degenerative disorders of the spine. In the presence of neurological symptoms, surgery is indicated. A preventive surgical procedure in asymptomatic patients is discussed controversially in the literature and is established in TCS patients only with correction of a scoliosis. However, most patients suffering from TCS benefit from surgical treatment.CM can be divided into four abnormal alterations of the posterior fossa, with most cases being of types I and II. In adults, Chiari type I is most common. Chiari I may present congenitally; however, it is also secondarily observed following lumboperitoneal shunting or in association with hydrocephalus. Surgical intervention is recommended depending on the extent of herniated tissue and the neurological symptoms. The optimal surgical procedure is still controversial. Most centers recommend bony decompression with dural graft extension for Chiari I.The appropriate treatment of both complex disorders requires a close and critical interdisciplinary approach in order to offer patients an individually adapted therapy.     

Surgical decompression for symptomatic Chiari II malformation in neonates with myelomeningocele.

Between January, 1981, and July, 1991, 17 infants under 1 month of age were admitted to The Hospital for Sick Children with the signs and symptoms of a Chiari II malformation. These patients' presentation included swallowing difficulty (71%), stridor (59%), apneic spells (29%), aspiration (12%), weakness of cry (18%), and arm weakness (53%). Decompression of the Chiari II malformation was performed in all patients, with a time interval between onset of symptoms and surgery ranging from 1 to 121 days. Fifteen patients (88%) remain alive, all of whom have shown a complete recovery. The mean follow-up period in this group of patients was 65 months. Two patients died, one due to respiratory arrest 8 months after decompression and the other because of shunt infection and peritonitis 7 years after decompression. These results support the concept that compressive forces, rather than a primary intrinsic disorder of the brain-stem nuclei, play a crucial etiological role in the development of a symptomatic Chiari II malformation. Early recognition of the symptoms of Chiari II malformation should be followed by immediate decompressive laminectomy in order to promote a prompt and full neurological recovery.     

枕颈部畸形合并颈脊髓空洞症的外科治疗

报告８例枕颈部畸形合并颈脊髓空洞症（Ｃｈｉａｒｉ畸形Ａ型）并经手术治疗。根据临床表现和影像学（ＭＲＩ）征象，应用枕骨大孔扩大，寰椎后弓切除减压，枕颈自体髂骨植骨融合及脊髓空洞蛛网膜下腔分流术。术后症状和体征明显改善７例，无变化１例。本文对有临床症状的Ｃｈｉａｒｉ畸形的发病和治疗进行了讨论．     

Surgical treatment of syringomyelia. Selection of surgical procedures

The surgical approach to syringomyelia is controversial. In this study, the authors evaluated the results of various operative procedures applied in 31 patients with syringomyelia. Syringomyelia was associated with Chiari malformation in 17 cases, with spinal adhesive arachnoiditis in nine, with trauma in three, and with epidural arachnoid cyst in one. One case was idiopathic. A total of 38 operations were performed. Syringosubarachnoid shunting was applied in 17 patients, syringoperitoneal shunting in 11, terminal syringostomy in three, ventriculoperitoneal shunting in three, lumboperitoneal shunting in two, foramen magnum decompression (suboccipital craniectomy plus upper cervical laminectomy) and terminal syringostomy in one, and foramen magnum decompression with syringosubarachnoid shunting in one. The postoperative follow-up period ranged from 2 to 55 months (average, 26 months). Of the 31 patients, 23 showed neurological improvement, five were unchanged, and three deteriorated. Among the last three, one patient with Chiari malformation developed shunt malfunction due to arachnoiditis after syringosubarachnoid shunting. In two patients with syringomyelia secondary to adhesive arachnoiditis, the spinal cord was damaged by extensive separation of the arachnoid membrane at surgery. On the basis of the results in these 31 cases, the authors conclude that syringosubarachnoid shunting is effective for syringomyelia associated with Chiari malformation if syringomyelia is responsible for the clinical symptoms. Post-traumatic syringomyelia and syringomyelia secondary to adhesive arachnoiditis should be treated by syringoperitoneal shunting. If hydrocephalus is present, ventriculoperitoneal shunting is indicated. Finally, terminal syringostomy is no more effective than syringosubarachnoid or syringoperitoneal shunting.     

Subarachnoid hemorrhage caused by a rupture of a spinal arteriovenous malformation

The authors report on a patient presenting with subarachnoid hemorrhage that was caused by a rupture of an spinal combined arteriovenous malformation at cervicothoracic junction. The patient was a 30-year-old female, who had exhibited an abrupt onset of severe low neck and occipital pain with radiation into shoulders and vomiting. Neurological examination revealed severe meningism without motor or sensory deficit. Digital subtraction angiography did not demonstrate any intracranial source of bleeding, whereas spinal angiography revealed a spinal arteriovenous malformation at cervicothoracic junction. Endovascular treatment of the malformation was considered for this patient. Occipital and neck pain with radiation into schoulders and severe meningism are clues pointing to a spinal origin of the haemorrhage.     

Recurrent psychogenic paresis after dural puncture in a parturient

We describe the case of a 29-year-old parturient who, after undergoing elective cesarean delivery, displayed symptoms of lower extremity weakness and sensory deficit. Her past medical history was significant for asymptomatic Arnold Chiari Type I malformation and asthma. She had received spinal anesthesia that failed to achieve an adequate surgical level requiring conversion to general anesthesia. After tracheal extubation, she exhibited bilateral leg weakness that did not resolve over the next 4–6 h. An urgent magnetic resonance imaging scan revealed a normal spine with no evidence of hematoma. The lower extremity paresis persisted and a neurologist diagnosed psychogenic paresis, a type of conversion disorder. Interestingly, the patient’s postoperative leg paresis was not her first occurrence of neurological dysfunction after dural puncture. At 27 weeks of gestation, she had similar lower extremity symptoms after a lumbar puncture, performed to exclude meningitis for severe headache symptoms. Psychogenic paresis is not commonly reported in the medical literature and we found no reports of psychogenic paresis after spinal anesthesia in a parturient or recurrent psychogenic paresis. We review the various risk factors, etiology, neurological signs and symptoms, types, therapy and future management of a patient with recurrent conversion disorder.