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.     

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.     

Presentation and management of Chiari I malformation in children

To determine the efficacy of operative treatment for children with Chiari I malformation, the medical records and magnetic resonance imaging (MRI) studies of 68 consecutive patients cared for at The Children's Hospital, Boston, Mass., USA, from December, 1988 to November, 1996 were retrospectively reviewed. All patients underwent suboccipital craniectomy, C1 laminectomy, and dural grafting. Bipolar coagulation to shrink and reduce the volume of the cerebellar tonsils was carried out in 40 patients. In 32 of 40 patients with associated syringomyelia, the procedure included placement of a IVth ventricle to cervical subarachnoid space shunt. Twenty-three patients with syringomyelia also had plugging of the obex. There was no operative mortality. Morbidity included a 22% incidence of nausea/vomiting and a 10% incidence of headache, both limited to the immediate postoperative period. Within the first postoperative month, all patients or their parents reported clear improvement in their presenting symptoms and 93% were found to have clear improvement in their presenting signs. In follow-up periods of 6-70 months, all patients had continued unequivocal symptom improvement and all patients were found on examination to have clear improvement in neurological signs. In patients with syringomyelia, MRI studies carried out at least 6 months postoperatively revealed near total or total syrinx resolution in 80% of the cases. This study demonstrates that a standard bony and dural decompression of the foramen magnum region with modifications designed to maximize the restoration of CSF circulation across the foramen magnum is a safe, effective operative treatment for Chiari I malformation in children.     

Audio-vestibular manifestations of Chiari malformation and outcome of surgical decompression: a case report

Sensorineural hearing loss, tinnitus, dizziness and ataxia are recognised symptoms associated with Chiari malformations but they are rarely the presenting complaints. Patients with such symptoms are frequently referred to otolaryngologists and audiological physicians. We report a case of a 13-year-old girl who presented complaining of tinnitus and impaired hearing, and was subsequently diagnosed as having a type I Chiari malformation. Pure tone audiogram showed a mild hearing impairment on the left side and the speech audiogram was normal. Auditory brain stem responses and the electronystagmography were abnormal. The patient underwent posterior fossa decompression following which her tinnitus disappeared, the hearing problem recovered and some of the abnormal electrophysiological parameters were corrected.     

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.     

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.     

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.     

Presentation and management of hydromyelia in children with Chiari type-II malformation

Hydromyelia in patients with myelomeningocele and Chiari-II malformation is a relatively frequent finding on MRI studies. However, not all children develop symptoms from the hydromyelia that requires treatment. Furthermore, treatment of hydromyelia in spina bifida patients is rather complex due to the associated malformations. The authors retrospectively analyzed 231 MRI studies carried out on spina bifida patients who presented neurological deterioration. Hydromyelia was found in 48.5% of the patients. Forty-five children with severe hydromyelia required treatment. These patients were first divided into 2 groups: those with holocord hydromyelia, and those with a segmental lesion. Fifteen patients presented symptoms characteristic of symptomatic Chiari-II malformation: neck rigidity; swallowing difficulty; pain in the upper extremeties; weakness or spasticity in the upper extremeties. Eighteen patients presented symptoms typical of the tethered cord syndrome: scoliosis; worsening bladder and/or bowel function; pain in the lower extremeties; weakness or spasticity in the lower extremeties. Twelve patients presented a mixed-type symptomatology. These patients subsequently underwent posterior cervical decompression, tethered cord release or insertion of a hydromyelia-pleural shunt according to the type of presenting symptoms and to the extent of the hydromyelic lesion. A pattern of successful treatment was identified for each type of presenting clinical and radiological picture. This has allowed the authors to determine an algorithm for optimal treatment of hydromyelia associated with Chiari-II malformation and myelomeningocele, which is proposed here.     

Extradural anaesthesia for caesarean section in a patient with syringomyelia and Chiari type I anomaly

We describe elective Caesarean section performed under extradural anaesthesia in a parturient with symptomatic syringomyelia and coexisting Chiari type I anomaly. Syringomyelia is reviewed and the anaesthetic implications of the condition discussed. Anaesthesia should be directed primarily at avoidance of increased intracranial pressure, which can cause sudden deterioration in these patients.     

Chiari malformation and tonsillar ectopia in twin brothers and father with autosomal dominant spondylo-epiphyseal dysplasia tarda

Open reduction of the radial head and reconstruction of the annular ligament has been advocated for the Monteggia fracture dislocation in children who present more than a month after injury. Three patients with an anterior Monteggia lesion were treated by open reduction of the radial head which was held in place by a Kirschner wire passed from the humerus to the radius. No attempt was made either to repair or reconstruct the annular ligament. The patients were aged between 2 and 6 years, the delay between injury and reduction was between 6 and 8 weeks, and the length of follow up was 5 years for two patients and 1 year for the third. All three patients were free of pain, had no deformity and the radial head had not subluxated. All had nearly full flexion at the elbow. The forearm had full supination but restricted pronation.     

Knockout and reconstitution of a functional human type I interferon receptor complex

The functional subunits of the human Type I interferon (IFN) receptor complex have not been defined. Using site-specific recombination in a yeast artificial chromosome (YAC), we have produced a deletion within the human IFN-alpha receptor (Hu-IFN-alpha R1) gene which eliminates exon II of the gene. This deletion effectively eliminates the MHC Class I antigen induction and antiviral activity previously reported for this fully functional parental YAC clone (Soh, J., Mariano, T. M., Lim, J.-K., Izotova, L., Mirochnitchenko, O., Schwartz, B., Langer, J., and Pestka, S. (1994c) J. Biol. Chem. 269, 18102-18110). We have successfully reconstituted this activity by expression of the cDNA encoding the Hu-IFN-alpha R1 component (Uzé, G., Lutfalla, G., and Gresser, I. (1990) Cell 60, 225-234) in cells containing the YAC with this deletion. The Hu-IFN-alpha R1 subunit thus plays a critical role in the functional human Type I IFN receptor complex, whose components are encoded on this YAC. In addition, as binding of ligands is retained in the cells containing the YAC with the deletion, it is clear a second subunit encoded on the YAC is responsible for ligand binding activity. This system will now allow the identification of additional subunits involved in the response to the Type I IFNs and the functional significance of each.     

Personality assessment of patients with complex regional pain syndrome type I

BACKGROUND: While routine clinical decision-making has a substantial effect on quality, most practising physicians do not routinely examine their outcomes. OBJECTIVES: To set up a practical process for identifying problems in hospital practices of primary care physicians, examine their causes, and develop a quality improvement process that intimately involves practising physicians in problem-solving. DESIGN: All hospital admissions to the Primary Care Service were screened over a 14-month period using simple pre-specified criteria. Quality problems were verified by medical record reviews carried out by two physicians. These problems were discussed at monthly meetings of physicians to characterize the problems fully, identify their causes, and document adverse effects on patient outcomes. SETTING: One community hospital. PARTICIPANTS: Primary care physicians from three group practices and four solo practices who admit patients to the Primary Care Service. INTERVENTIONS: Monthly group discussions plus discussions with individual physicians when time did not permit all quality problems to be discussed at group meetings. Certain issues of high sensitivity were also discussed with the individuals rather than in an open forum. OUTCOME MEASURES: Missed or delayed diagnoses, inappropriate treatments, and complications and their root causes. RESULTS: Quality problems were identified in 6% of all admissions. Of these, 60% were missed or delayed diagnoses, 22% were iatrogenic complications and 18% were inappropriate treatments. Root cause analysis suggested that physician behaviors led to 75% of problems; systems problems to 20% and inadequate knowledge to 5%. Process improvements included development of a call-in system to reduce delays in obtaining X-ray reports; implementation of an anticoagulation monitoring system in one group practice; and a protocol of regular feedback of errors in diagnosis to emergency room physicians. Participating physicians reported increased awareness of common errors and greater attention to detail in patient evaluations. CONCLUSIONS: Knowledge of root causes of quality problems is essential for improving quality of care. A simple routine approach to examining adverse outcomes and how care might be improved in the future was set up. Active participation of practising physicians is essential. Other organizations could use this process for routinely reviewing and improving quality.     

On the surgical treatment of refractory epilepsy in tuberous sclerosis complex

Using the pig as a model, it was shown that stimulation of the distal nerve ending of the pudendal nerve leads to the isolated stimulation of the external anal sphincter muscle. No difference in pressure response was noted after application of between 0.5 and 1.5 mA unilateral or bilateral stimulation. Major advantages observed using between 1.5 and 2.5 mA bilateral stimulation; with a stimulation between 2.0 and 2.5 mA the pressure response was twice as high compared to unilateral stimulation. Continuous stimulation of the striated anal sphincter muscle leads to fatigue, reaching 50% fatigue after a median time between 40-90 s. In cyclic stimulation (alternation every 15 s, duration 20 min) a fatigue reaction was also seen. The peak pressure decreased after 20 min for a median of 11%, the final pressure was lowered in 15% following a logarithmic curve pattern. The experimental application of variable impulse ranges also caused pressure differences. Increasing the impulse range from 200 to 450 microseconds (peak pressure) vs. 400 microseconds (final pressure) resulted in a statistically significant pressure increase. Therefore, it was proven that selective stimulation of the external anal sphincter muscle can lead to a transient pressure increase, which possibly improves fecal continence.     

A case of diastematomyelia (split cord malformation type I) with clinical manifestation in adulthood

We present the case of a female patient with split-cord malformation type I (diastematomyelia) who developed first symptoms as an adult and worsened markedly after intramedullary injection of local anaesthetics. Our own observations are compared with the small number of cases known from the literature. We are using the morphological and clinical classification of spinal malformations of Pang et al. (1992), which is based on a uniform disturbed embryonal development [18, 19]. The 52-year-old patient presented to her family physician in September 1991 with pain in the region of the vertebral column which had developed gradually over a period of two weeks. Following unsuccessful analgetic and muscle-relaxing therapy, the family physician had the patient transferred to the orthopedic department of a hospital. Lumbar peridural infiltrations were carried out there in February 1992 for a suspected disc prolapse. Since June 1992, she had no longer been able to walk. In addition, there had also been a progredient urinary incontinence since April 1992. The spinal CT scan reveals a duplication of spinal cord starting at the level of L4 as well as a bony spur dividing the spinal cord at levels L4 and L5. MRI of the vertebral column likewise reveals a duplication of the spinal cord starting at L4 as well as a low conus and a bone spur extending from L4 to L5 is also visualized here. Each primordial spinal cord is surrounded by its own dura mater. Altogether, this led to the diagnosis of split cord malformation type I according to Pang et al. [18].(ABSTRACT TRUNCATED AT 250 WORDS)     

Sexual ambiguity and malformation in Zambia: challenges in surgical management

This article addresses the complexity in diagnosis, gender assignment and management in patients with sexual ambiguity and malformed sexual organs. Between 1984 and 1993, nine children and 10 adult patients with this ailment were treated in the University Teaching Hospital, Lusaka, Zambia. All children had clitorovaginoplasty and adults had different surgical procedures such as feminisation and masculinisation operations. Methods, means and the manner in which we manage these patients in the midst of a scarcity of expert manpower and sophisticated equipment are discussed. Need for a specialised clinic for better management, teaching and research of this unfortunate and highly sensitive congenital defect has been emphasised.