The outcome of adjusted accumulation dose of treatment of Graves'' disease

Etiology of syringomyelia associated with Chiari type I malformation has been unknown. Moreover, the surgical procedure of foramen magnum decompression for this type of syringomyelia has not been standardized yet. No one procedure has been always successful, leading to many alternative procedures. The purpose of the present study is to elucidate pathway of cerebrospinal fluid into the syrinx cavity and to find out the best procedure for this disease. Fourty two patients with syringomyelia associated with Chiari type I malformation, which were diagnosed with magnetic resonance imaging (MRI), underwent surgical treatment. In all patients, craniocervical junction anomalies, cervical disc herniation and other spinal diseases were ruled out. There were 26 men and 16 women, ranging from 6 to 72 (mean: 42.3) years in age. The size, length and position of upper end of each syrinx cavity and the degree of the tonsillar herniation were measured on preoperative T1-weighted image and were compared each other. There were no significant relationship between the degree of tonsillar herniation and the size, length and position of syrinx cavity. No case showed that the upper end of syrinx cavity communicated to the 4th ventricle. The results suggest that the pathway of cerebrospinal fluid into the the syrinx cavity was not central canal from the 4th ventricle but microcanals in the spinal cord. All patients were carried out with foramen magnum decompression, which was divided into 4 groups according to the degree of decompression: 1) tonsillectomy group: 12 patients underwent subocciptital craniectomy (SOC) with patcy-graft dural plasty using lyophilized dura mater and tonsillectomy, 2) lysis group: 7 underwent SOC, dural plasty and microsurgical lysis of arachnoidal trabecula and fibrinoid filament around herniated tonsil, 3) plasty group: 17 underwent SOC and dural plasty and 4) dural group: 6 underwent SOC and removal of the outer layer of the dura mater. The mean follow-up periods were 3.7 years in tonsillectomy group, 3.6 years in lysis group, 2.3 years in plasty group, 1.8 years in dural group, respectively. Evaluation of the result following four types of surgical treatments was performed on clinical symptoms and the volume of syrinx cavity on sagittal MRI. The ratio in the area of the syrinx and spinal cord on preoperative and postoperative sagittal MRI were measured. There was no significant difference among 4 groups on the degree of reduction of syrinx in the sagittal plane as evaluated on MRI, whereas with regards to improvement of the clinical symptoms, dural group was significantly worse than the other three groups. The surgical procedure of dural plasty was clearly less invasive than those of tonsillectomy and lysis of subarachnoidal trabecula. These results suggest that we should select dural plasty as a primary surgical procedure for syringomyelia associated with Chiari type I malformation.     

Clinical and neuroimaging features of Chiari type I malformations with and without associated syringomyelia

The clinical and neuroimaging characteristics of 22 consecutive patients with Chiari type I malformations were evaluated to investigate the pathogenesis of syrinx formation. All patients underwent magnetic resonance imaging and x-ray tomography before surgery. The electric manometric Queckenstedt test was performed on 16 patients pre- and postoperatively. Syringomyelia was present in 17 patients and absent in five patients. All patients without syringomyelia suffered from foramen magnum compression syndrome, with a wider basal angle, more acute clivo-axial angle, shorter clivus, and more prominent tonsillar ectopia than patients with syringomyelia. Low brain stem position, basilar impression, and beaking of the cervicomedullary junction were also more prominent in patients without syringomyelia. Marked to complete block with the neck in flexed position by Queckenstedt test was present in all patients except one. Patients with Chiari malformation not associated with syringomyelia have more pronounced compression of the brain stem at the foramen magnum. Therefore, despite a block of the cerebrospinal fluid pathway at the foramen magnum, syrinx formation may be prevented by severe compression.     

Hydrodynamics of syringomyelia

Abnormality of CSF hydrodynamics is an important factor of the pathogenesis of syringomyelia. Recent development of cine-MRI visualized real time CSF movement in the syrinx or subarachnoid space. In the present study, twenty cases of syringomyelia associated with Chiari I malformation, 10 cases of syringomyelia associated with spina bifida aperta, and 10 cases of syringomyelia associated with spina bifida occulta were studied with MRI and cine-MRI. The result demonstrated that hydrodynamics of these three groups were different to each other. Chiari I malformation showed CSF hydrodynamic abnormality at the foramen magnum and marked flow void in the syrinx. On the other hand, myelomeningocele showed hydrocephalus and less prominent flow void in the syrinx. Spinal lipoma which is the majority of spina bifida occulta showed no abnormality of CSF hydrodynamics. In conclusion, the selection of treatments should be individualized depending on the hydrodynamical abnormality of each patient.     

Encapsulated egg deposition pattern of Schistosoma japonicum in the peritoneal cavity of mice

Cine-MRI with presaturation bolus tracking was used in patients with syringomyelia associated with a Chiari malformation to study pulsatile movement of the hindbrain, cervical spinal cord, cerebrospinal fluid and the fluid within the syrinx. Nine patients had 13 examinations, 6 preoperative, 3 after syringosubarachnoid shunting and 4 after posterior fossa decompression. Five controls were also examined. Dynamic display of the acquired images demonstrated downward displacement of the presaturation bolus on the cerebellar tonsils and medulla oblongata (or upper cervical cord) at the C1 level in all preoperative examinations and in two patients after syringosubarachnoid shunting but with residual foramen magnum obstruction. Downward displacement of the bolus on the cervical spinal cord was also demonstrated in 7 examinations, but not observed in the controls. Thus, the hind-brain-spinal cord axis showed larger pulsatile movements in patients with foramen magnum obstruction. Based on these observations and a review of the literature, a new theory on the mode of extension of syringomyelia, emphasising the role of increased pulsatile movement of the hind-brain-spinal cord axis is proposed: that the pulsatile movements, together with a one-way valve mechanism in the syrinx cavity act as a "vacuum-pump" to enlarge the syrinx.     

Posterior fossa decompression for Chiari I deformity, including resection of the cerebellar tonsils

This is an analysis of 19 consecutive cases of symptomatic patients with Chiari I deformities, undertaken to evaluate the long-term effect of posterior fossa decompression and duraplasty, assessed by postoperative imaging. Sixteen of the patients had syringomyelia and three had foramen magnum syndromes without a syrinx. Eighteen patients underwent posterior fossa craniectomy, subpial resection of the cerebellar tonsils, and duraplasty. Four patients were 16 years of age or younger. One of the children with syringomyelia had a posterior fossa decompression without resection of the tonsils. In the 15 patients with syringomyelia whose surgery included resection of the tonsils, the syrinx was reduced or resolved in 14. The patient whose syrinx did not change was a child with a lumbosacral lipoma. Three patients had syndromes of the foramen magnum without a syrinx, and of these only a patient with prior chemical and bacterial meningitis caused by a lumboureteral shunt failed to improve dramatically. When our patients are combined with 40 in the literature treated by decompression and duraplasty, 51 of 55 patients had reduction or resolution of the syrinx. Although it does not clearly affect the result, resection of the tonsils can be done safely.     

Otoneurological manifestations in Chiari-I malformation

The type I Chiari malformation consists of a caudal displacement of the cerebellar tonsils through the foramen magnum into the cervical spinal canal. The most common presenting symptoms, such as pain, weakness and headache, are frequently preceded by otoneurological symptoms. Sensorineural hearing loss, vertigo, nystagmus, dysequilibrium, tinnitus and other cranial nerve involvement have been reported in Chiari-I malformation. A case report is presented and the clinical features of the disease are discussed with emphasis on the otoneurological aspects.     

Surgical technique for cranio-cervical decompression in syringomyelia associated with Chiari type I malformation

Our purpose is to present our results with the surgical treatment of syringomyelia associated with Chiari type I malformation. Between October 1989 and October 1995, twenty-eight patients underwent a sub-occipital craniotomy and a C1 laminectomy. After dura mater opening the cerebellar tonsils were mobilised. Neither catheter, nor plugging of the obex, nor tonsillar tissue removal was performed. The dura mater was enlarged by means of a wide graft to create a new cisterna magna of adequate size. Postoperative MRI scans showed an ascent of the cerebellum of 4.3 +/- 4.8 mm (measured by the fastigium to basal line), as well as of the brainstem (mean migration of the mesencephalon-pons junction of 4.3 +/- 3.3 mm). The tonsils emigrated cranially 6.5 +/- 4.8 mm. While preoperative mean syringo-cord ratio was 66.3% +/- 13.3, post-operatively was 12.1% +/- 12.7 (p < 0.0001). A complete collapse of the syrinx was observed in 39% of the patients. Long-term improvements were obtained in 73% of the cases and 27% were unchanged. No patient got worse. We conclude that in the treatment of syringomyelia associated with Chiari I malformation an artificial cisterna magna of sufficient size must be created. This is achieved by means of an extensive sub-occipital craniotomy and C1 laminectomy, followed by dural opening. Small bone removal with limited enlargement of the posterior fossa often results in failures of treatment and recurrences. Tonsillar removal is not necessary to obtain a good reconstruction of the cisterna magna.     

Chiari I malformation associated with syringomyelia and scoliosis

STUDY DESIGN: A retrospective review of a series of 12 children who underwent suboccipital foraminotomy and duroplasty for Chiari I malformation. OBJECTIVE: To assess the effects of this surgery on associated syringomyelia and scoliosis. SUMMARY OF BACKGROUND DATA: Suboccipital foraminotomy for the treatment of syringomyelia associated with Chiari I malformation was greatly stimulated by Gardner's hydrodynamic theory, and its results proved to be encouraging. However, several authors reported improvement or stabilization of associated scoliosis after this surgery. METHODS: A retrospective review was conducted on 12 patients who underwent suboccipital foraminotomy for Chiari I malformation associated with syringomyelia. Neurologic Impairment, extent of syringomyelia, and severity of associated spinal deformity were assessed preoperatively and at a 4.5-year average follow-up (range, 2.1-12 years). Anomaly of superficial abdominal reflexes was found in all cases, and para or tetraparesis in three cases. Syringomyelia was of variable localization and extent. Scoliosis was present in 7 cases (greater than 40 degrees in 5 cases). RESULTS: Diminution or complete disappearance of syringomyelia was observed in 11 cases, 3 months to 1 year after surgery. Superficial abdominal reflexes anomaly improved in four cases. Minimal neurologic deficit persisted in one case. Scoliosis improved in one case, remained unchanged in one case, and progressed in the five cases with preoperative severe deformity, requiring instrumentation and fusion. CONCLUSIONS: Improvement of syringomyelia and neurologic deficit, observed with suboccipital foraminotomy, supports the theory that abnormal hydrodynamics of the cerebral spinal fluid is most likely to cause these deficits.     

Primary craniovertebral anomalies and the hindbrain herniation syndrome (Chiari I): data base analysis

This prospective study analyzes 100 patients with Chiari malformation and primary craniovertebral junction (CVJ) anomalies (3-66 years). Neurodiagnostic investigations employed tomography, gas myelography, CT and CT myelography, and MRI. Factors considered were reducibility, mode of encroachment, cerebrospinal fluid (CSF) dynamics and syringohydromyelia. Sixty-six patients with irreducible pathology underwent ventral or ventrolateral decompression and dorsal stabilization. Dorsal occipitocervical fixation was performed in reducible lesions that also required dorsal decompression (n = 34). Proatlas remnants were identified in 8 and atlas assimilation in 92 patients. Paramesial invagination was present in 20, syringohydromyelia in 46, and vertebral segmentation defects in 66 others. Completely reducible abnormalities were identified in 16 of 20 patients aged 2-14 years, and partially reducible abnormalities in 4 of 16 patients aged 14-20 years, 8 of 48 patients aged 20-40 years and 6 of 16 patients aged 40-60 years. The critical sagittal canal diameter at the foramen magnum was 19 mm. Twenty-two patients had previous posterior decompression and 27 had previous syrinx to subarachnoid shunt with delayed deterioration. Improvement occurred in all after ventral or ventrolateral decompression with resolution of the syringohydromyelia and normalization of CSF flow. We conclude that: (1) hindbrain herniation syndrome is frequently seen with fourth occipital sclerotome abnormalities; (2) Chiari malformation with craniovertebral abnormalities become symptomatic with a canal diameter of < 19 mm; (3) abnormal ventral bony pathology is reducible in children wit atlas assimilation and later becomes irreducible invagination, therefore early operation with fusion is recommended; (4) ventral decompression relieves brain stem, cerebellar symptoms and syringohydromyelia; (5) CSF studies with cine MRI shows reversal of craniospinal CSF dissociation after ventral CVJ decompression and; (6) craniovertebral anomalies associated with Chiari malformations must be addressed early and appropriately.     

Clinical features and MR imaging in children with repaired myelomeningocele

The aim of the study is to define the role of associated malformations in the clinical evolution of children affected by myelomeningocele. MRI investigation of the spinal cord was carried out on 25 patients between the age of 7.3 and 18.10 with MMC repaired and followed up for at least 7 years. The relation between associated malformations demonstrated by MRI and clinical trend was analysed. The results are the following: 1) presence of asymptomatic tethered cord in all cases; 2) high frequency (92%) of Chiari malformation; 3) presence of syringomyelia in 20% of patients, symptomatic in 1; 4) presence of ventricular enlargement in 72% of cases without increased intracranial pressure syndrome. For a better therapeutic approach prospective MRI studies are needed in order to follow up associated malformations.     

Chiari Type I malformation and syringomyelia in unrelated patients with blepharophimosis. Report of two cases

Syringomyelia is a rare, mainly sporadic disease of the spinal cord, which is associated with 80% of cases in which a Chiari Type I malformation is also present. A mendelian transmission of syringomyelia (autosomal dominant or recessive) has been proposed in approximately 2% of reported cases. The association of syringomyelia with hereditary diseases (Noonan's syndrome, phacomatoses) has been mentioned frequently in the literature. The authors report the presence of a Chiari Type I malformation accompanied by syringomyelia in two unrelated patients affected by a familial Type II blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). The first patient was a 35-year-old woman who presented with a right C-8 root paresia. The second case involved a 20-year-old man who complained of cervical radicular pain. Both belong to families in which BPES was segregated in an autosomal dominant modality, but other family members had no known neurological symptoms. To the authors' knowledge, such a combination has never been described. Perhaps the possible involvement of a genetic component in some cases of Chiari Type I-associated syringomyelia will someday be debated.     

Isolated partial growth hormone deficient short stature with syringomyelia not associated with birth injury

A 59-year-old female with 20-year history of slowly progressing muscle atrophy and sensory disturbance of upper extremities showed short stature, scoliosis, hunger type of sensory dissociation of the upper extremities and pyramidal tract sign of the lower extremities. Magnetic resonance imaging (MRI) clarified hypoplasia of the anterior pituitary lobe, Arnold-Chiari malformation and cervical syringomyelia. Insulin and arginine stimulating tests revealed partial type of isolated growth hormone (GH) deficiency but GH gene analysis detected no defects of GH genes. It was considered to be a rare case of non-hereditary hypopituitarism with Chiari malformation and syringomyelia not associated with perinatal injury, namely a midline anomaly syndrome.     

Posterior fossa decompression without duraplasty in infants and young children for treatment of Chiari malformation and achondroplasia

Some children with Chiari malformation and achondroplasia require posterior fossa decompression that typically includes expansion of the dural tube with duraplasty. Infants and young children, however, may have a more distensible dura mater than do older patients. Furthermore, the structures that compress the hindbrain of young patients may be the bone and abnormally thickened atlantooccipital membrane, i.e., dural band, rather than the dura mater. We have treated 7 children who had Chiari malformation or achondroplasia with posterior fossa decompression without duraplasty. All children were symptomatic; 3 had Chiari-I malformations, 2 Chiari-II malformations, and 2 achondroplasia. The age range was 3 months to 2.5 years (mean 15.1 months). The exent of tonsillar herniation and other hindbrain anomalies was assessed on preoperative magnetic resonance imaging. The infants with Chiari-II malformations underwent cervical laminectomies, whereas the other young children with Chiari-I malformations or achondroplasia underwent suboccipital craniectomy as well as cervical laminectomy. In Chiari malformation, the dural band was divided; in achondroplasia, there was no identifiable dural band. Following bony decompression and division of the identifiable dural band, immediate expansion of the stenotic region with visible cerebrospinal fluid space posterior to the neural elements could be ascertained by intraoperative ultrasonography. During a follow-up period ranging from 4.5 months to 4 years (mean 22 months), all patients made improvements in their symptoms, 3 having complete resolution of their symptoms. This preliminary experience indicates that in children 2 years of age or younger, posterior fossa bony decompression without duraplasty can be effective treatment for Chiari malformations or achondroplasia.     

Current surgical treatment of Chiari type I malformation and Chiari I-syringomyelia complex

Chiari type I malformation and so-called Chiari-I/syringomyelia complex continue to inspire controversy. Disagreement on these malformations concern both etiopathogenesis and treatment. Our still poor understanding of the natural course of the disease, the lack of consensus regarding therapeutic indications and even disagreement on appropriate surgery all contribute to cause disagreement. Significant progress has been made in our understanding of contributing etiopathogenetic factors in recent years. The most widely accepted hypothesis is that anomalous embryonic development characterized by paraxial mesodermal insufficiency would put volumetric constraints on postnatal development of the posterior fossa. We review historical and current controversies regarding Chiari type I malformation and classic theories on causative and contributing factors. We also discuss the latest surgical treatments that have been suggested, as well as associated anomalies--mainly syringomyelia, hydrocephalus and malformed cranial-cervical articulation. Finally, we propose a protocol useful for the diagnosis and treatment of Chiari type I malformation associated with dilation of the ventricular system.     

Effects of zinc supplementation on the immune system and on antibody response to multivalent influenza vaccine in hemodialysis patients

BACKGROUND: It has been theorized that fetal myelomeningocele repair may reduce ongoing intrauterine injury and perhaps allow healing and regeneration of dysplastic neural tissue. We report on the postnatal imaging studies of the first 4 patients to have undergone intrauterine myelomeningocele repair at our institution. METHODS: Each of the 4 patients underwent postnatal sonographic and MRI. In addition, the postnatal ultrasounds of these 4 were compared to a group of retrospective controls. RESULTS: MRI scans of the 4 experimental subjects revealed no evidence of hindbrain herniation while other stigmata of the Chiari-II malformation persisted. In comparison to the retrospective controls this absence of herniation was distinctly unusual. CONCLUSION: Intrauterine myelomeningocele repair may reduce the degree of hindbrain herniation normally seen in patients with myelomeningocele. This raises the possibility that intrauterine repair may decrease the morbidity associated with the Chiari type-II malformation including brainstem dysfunction, hydrocephalus and syringomyelia.     

Syringomyelia following lumboureteral shunting for communicating hydrocephalus. Report of three cases

Three patients are described in whom syringomyelia was identified long after the treatment of communicating hydrocephalus by a lumboureteral shunt. The reason for syrinx formation in these cases could not be determined. In two there was either autopsy-proven or presumed evidence for arachnoiditis, and in the third patient the symptoms of syringomyelia were acutely aggravated by temporary obstruction of shunt. The development of a pressure drop from the intracranial compartment to the spinal compartment with crowding at the foramen magnum is also a suggested mechanism.     

Nutrient content of tomatoes and tomato products

We report nine patients with hypoglossal nerve palsy as the sole neurological manifestation, without simultaneous involvement of other cranial nerves or long-tract signs. In four patients, no cause was found and the outcome was excellent. The next common cause proved to be metastatic disease at the base of the skull in three patients. Two exceptional causes were Chiari malformation in one case and dural arteriovenous fistula of the transverse sinus in another. Although the aetiological importance and ominous prognosis of neoplasia has been emphasized by others, our study suggests that an isolated hypoglossal nerve palsy may be benign and idiopathic.     

Utility of early postoperative MRI in hindbrain-related syringomyelia. A preliminary prospective study on five patients

We report a series of five patients operated on for hindbrain-related syringomyelia with posterior fossa decompression and duraplasty. In all cases an early postoperative MRI was performed (24-36 h after surgery). These images have been compared with the preoperative ones and with those obtained, 1, 3 and 6 months after operation. Both before and after surgery there was not always a tight correlation between clinical and MRI pictures. In all but one patient the early postoperative MR images showed a reduction of syrinx size and were as to those obtained later. We discuss the results observed in our small series and analyze the role of early postoperative MRI studies in patients with hindbrain-related syringomyelia.     

Characterization of circulating immune complexes in leprosy patients and their correlation with specific antibodies against Mycobacterium leprae

Thirty patients between the ages of 7 months and 24 years were treated surgically for symptomatic Chiari II malformation at the Arkansas Children's Hospital. All patients underwent at least bony decompression of the malformation. Assessments of the patients' conditions were made at 6 weeks and 1 year after surgery, and complications of surgery were noted. For a majority of the patients, the presenting symptoms were resolved following treatment (74% at 6 weeks and 80% at 1 year). Partial resolution occurred in several of the patients (17% at 6 weeks and 14% at 1 year). A small number remained the same at 6 weeks (6%) and at 1 year (3%), while 1 patient was worse after surgery. Ten of the patients with complete resolution in the short term required repeat surgery an average of 49 months after their original operation, after which they again attained complete resolution of their symptoms. Scales for clinical, radiographic and operative grading of the patients' conditions as mild, moderate or severe were devised, and these were employed to characterize the condition of each patient. Patients in each grading category had good results, with rates of complete symptomatic resolution ranging from 67 to 100%. Severity in each category was found to be well correlated with eventual recurrence of symptoms and need for reoperation.     

One-step fluorescent probe product-enhanced reverse transcriptase assay

The Chiari type II malformation is the leading cause of death in infants with myelomeningocele. The authors report 17 cases of symptomatic Chiari type II malformation occurring in two distinct age dependent population. In Group I, 13 neonates and infants in the first year of life presented with cranial nerve and brain stem dysfunction characterized by vocal cord paralysis, apnea, dysphagia and laryngeal stridor. In Group II, 4 patients developed signs and symptoms after the first year of life. In this group, the presentation was more insidious and included neck pain and cerebellar manifestations. The surgical treatment consisted initially in shunt implantation or revision and when there was no improvement, posterior fossa decompression was performed. The response to the surgical treatment differed considerably between the two groups: older patients improved promptly after surgery and there was no casualties; in newborn and infants, especially those under 6 months of age, the mortality rate was 46.1%. The authors stress that prompt diagnosis and surgical intervention should be performed in order to produce a favorable outcome.