Median Nerve Somatosensory Evoked Potentials in Patients with Chiari Malformation

Abnormal SEP reflects dysfunction of the medial lemniscus and posterior cervical cord. These structures are likely to be affected in Chiari malformation. Therefore, SEP abnormalities may provide valuable information in patients with CM. However, the consistency of SEP abnormality or normality with the damage is a matter of research. Knowing whether median nerve somatosensory evoked potential (SEP) is useful in revealing subclinical damage in patients with Chiari malformation is important in the treatment and follow-up plan of the disease. The aim of this study was to investigate the relationship between median nerve SEP values and the severity of cerebellar ectopia in patients with Chiari type 1 malformation. Median nerve SEP values were obtained from 30 healthy individuals and 146 individuals with Chiari malformation. The cerebellar ectopia degree and McRae line length were measured. SEP values were not significantly different between groups. The McRae line was found to be significantly shorter in the control group than in the Chiari malformation group (p = 0.031). There was no correlation between the degree of cerebellar ectopia and the length of the McRae line (r = 0.002, p = 0.979). Neither cerebellar ectopy degree nor McRae line length had a relationship with SEP values (r = -0.153, p = 0.066;r = -0.056, p = 0.500, respectively). There was no difference in cerebellar ectopy degree or SEP values between the groups with cerebellar ectopy with and without a syrinx (p = 0.899;p = 0.080, respectively). Likewise, McRae line length was not found to be related to the presence of a syrinx (p = 0.139). Median nerve SEP examination was not beneficial for diagnosing asymptomatic-oligosymptomatic Chiari malformation as a subclinical injury, whether accompanied by syringomyelia or not.

A benchtop brain injury model using resected donor tissue from patients with Chiari malformation

The use of live animal models for testing new therapies for brain and spinal cord repair is a controversial area. Live animal models have associated ethical issues and scientific concerns regarding the predictability of human responses. Alternative models that replicate the 3 D architecture of the central nervous system have prompted the development of organotypic neural injury models. However, the lack of reliable means to access normal human neural tissue has driven reliance on pathological or post-mortem tissue which limits their biological utility. We have established a protocol to use donor cerebellar tonsillar tissue surgically resected from patients with Chiari malformation(cerebellar herniation towards the foramen magnum, with ectopic rather than diseased tissue) to develop an in vitro organotypic model of traumatic brain injury. Viable tissue was maintained for approximately 2 weeks with all the major neural cell types detected. Traumatic injuries could be introduced into the slices with some cardinal features of post-injury pathology evident. Biomaterial placement was also feasible within the in vitro lesions. Accordingly, this ‘proof-of-concept’ study demonstrates that the model offers potential as an alternative to the use of animal tissue for preclinical testing in neural tissue engineering. To our knowledge, this is the first demonstration that donor tissue from patients with Chiari malformation can be used to develop a benchtop model of traumatic brain injury. However, significant challenges in relation to the clinical availability of tissue were encountered, and we discuss logistical issues that must be considered for model scale-up.

Coexistence of Pseudotumor Cerebri and Chiari Malformation Type 1

Objective:To identify different radiological markers for the diagnosis of the coexistence of pseudotumor cerebri and Chiari malformation type 1.Method:Patients who were clinically suspected to have Chiari malformation type 1 and were referred to the Department of Radiology between 2007 and 2020,and whose diagnosis was radiologically confirmed through magnetic resonance imaging(MRI),were retrospectively evaluated.A total of 49 Chiari malformation type 1 patients with both cervical and cerebral examinations and 49 control subjects of the same age and gender without a diagnosis of Chiari malformation type 1 were included in the study.In Chiari malformation type 1 diagnosed patients,the presence of pseudotumor cerebri,the presence of syringomyelia in cervical spinal MRI images,and the distance of cerebellar tonsils and obex according to McRae line were evaluated in millimeters.Result:In Chiari malformation type 1 clinically and radiologically diagnosed cases,the cerebellar tonsils and obex were located lower in patients with a radiological diagnosis of pseudotumor cerebri compared to those without,and the rate of accompanying syringomyelia appeared to be higher.However,no statistically significant difference was observed between the two groups.Conclusion:The coexistence of pseudotumor cerebri and Chiari malformation type 1 is more common than previously estimated.Different treatment protocols in the coexistence of pseudotumor cerebri and Chiari malformation type 1 emphasize the importance of making this diagnosis.Further radiological imaging studies are needed to identify different radiological markers for the diagnosis of the coexistence of pseudotumor cerebri and Chiari malformation type 1.

Chiari malformations in children:An overview

Chiari malformations encompass various radiological and clinical entities,sharing the herniation of the rhombencephalic structures through the foramen magnum as a common characteristic.They can be symptomatic or asymptomatic.The therapeutic strategies for these malformations differ on the basis of the diverse pathophysiologic processes that cause them.As Chiari malformations are caused by various pathophysiologic processes,they must be recognized promptly to select the best treatment for each single case.

Chiari Malformation Type 1 in Adults Managed by Surgical Decompression: New Prospective

Aim of the work: This study aims to assess the value of the surgical management in the improvement of the symptoms & signs of patients with Chiari malformation type 1 and radiological follow up in adults. Patients and methods: This study included 30 consecutive patients with Chiari malformation type I who were indicated for surgery at neurosurgery department. Data were collected prospectively from the involved patients who were evaluated preoperatively and underwent evaluation by CT scanning of the brain & skull and MRI imaging of the brain and spine. CT and MRI were done as the routine follow up investigations for all patients. We operated through midline suboccipital craniectomy, durotomy in y shaped manner, shrinkage of cerebellar tonsils by bipolar electrocautery, duroplasty by fascia lata graft, watertight closure. Results: The assessment from E. J. N. S. (Egyptian Journal of Neurosurgery) vol. 24 no. 2 June 2009 used for evaluating the patients clinically. 18 patients reported good outcome, 6 fair, 6 poor. We evaluated the size of the syrinx if present preoperative in follow up. 15 (50%) patients showed marked reduction (more than or equal to 60%) in size of syrinx, 3 (10%) mild reduction (less than or equal to 30%) in size and 12 (40%) with no change. Conclusion: The Chiari type 1 malformation constitutes a controllable malformation with good outcomes. With current microsurgical techniques, the results of the bony decompression and duroplasty became excellent. Before undergoing surgical treatment for CM-I, symptomatic patients and their families should be given clear information about the success of treatment and potential complications.

Endoscopic foramen magnum decompression for Chiari malformation

Objective To investigate the methods and effectiveness to treat Chiari malformation with surgical decompression of foramen magnum under endoscope. Methods 23 cases with Chiari malformation. (withoutatlanto-axial dislocation and basilar invagination) diagnosed by magnetic resonance imaging(MRI) were operated with the surgical decompression for foramen magnum under the endoscope. Results 23

Clinical Efficacy of Minimally Invasive Subpial Tonsillectomy(MIST)for Treatment of Chiari Malformation(TypeⅠ)with Syringomyelia

Background To investigate the clinical efficacy of minimally invasive subpial tonsillectomy(MIST)in the treatment of Chiari malformation(type I)with syringomyelia.Methods A total of 209 Chiari malformation(type I)patients with syringomyelia were studied.The patients were grouped based on the syrinx diameter changes:complete disappearance group(48 patients),obvious shrinkage group(147 patients),and non-obvious shrinkage group(14 patients).The Chicago Chiari Outcome Scale(CCOS)was used to compare clinical data of the three groups of patients before treatment.The correlations between disease duration and syrinx diameter changes as well as post-treatment clinical symptoms were analyzed.The related factors of efficacy were analyzed.Results Age and disease duration were the oldest/longest in the non-obvious shrinkage group,and the youngest/shortest in the complete disappearance group(P<0.05).The maximum diameter reduction of syrinx was the greatest in the complete disappearance group,and the smallest in the non-obvious shrinkage group(P<0.05).The proportions of patients with hypoesthesia,limb weakness,and muscle atrophy were the largest in the non-obvious shrinkage group,and the smallest in the complete disappearance group(P<0.05).The CCOS score were the highest in the complete disappearance group,and the lowest in the non-obvious shrinkage group(P<0.05).There were statistically significant(P<0.05)negative correlations between disease duration and maximum diameter reduction of syrinx,CCOS pain score,CCOS non-pain score,CCOS functionality score,and CCOS complication score,disease duration and hypoesthesia,limb weakness,muscle atrophy,and sleep apnea.Result of multivariate stepwise regression analysis indicated that age,disease duration,and preoperative syrinx diameter were the risk factors for efficacy(P<0.05).Conclusion For patients with Chiari malformation complicated by syringomyelia,the longer the disease duration,the more difficult it is to achieve syrinx reduction and improve the clinical symptoms.“Minimally invasive subpial tonsillectomy(MIST)and cisterna magna reconstruction”is an improved surgical approach to treat Chiari malformation(cerebellar tonsil herniation).It has the advantages of small incision,less postoperative reaction,and fewer complications,and it emphasizes the reshaping and repair of cerebellar tonsils,reconstruction of cisterna magna,and restoration of cerebrospinal fluid circulation.

Concomitant achondroplasia and Chiari II malformation: A double-hit at the cervicomedullary junction

We report the first case of a neonate with concurrent Chiari II malformation and achondroplasia. Although rare, both these conditions contribute to several deleterious anatomical changes at the cervicomedullary junction and thus predispose to acute hydrocephalus. Although our patient was initially asymptomatic, hydrocephalus ensued several weeks after birth and required cerebral spinal fluid diversion. We discuss the potential links between the two conditions, the pathophysiology, and the important clinical implications for the management of the increased risk of hydrocephalus.

Treatment of syringomyelia using uncultured umbilical cord mesenchymal stem cells: A case report and review of literature

BACKGROUND Syringomyelia is a disease caused by the formation of a cavity inside the spinal cord and is accompanied by such symptoms as pain,paresthesia,and urination and defecation disorders,and in severe cases causes various paralyses.Currently,there are only surgical methods for the treatment of syringomyelia,but these methods carry the possibility of failure,recurrence,and side effects.CASE SUMMARY The patient was a 59-year-old woman who suffered from pain due to syringomyelia.For treatment,the patient received transplant of uncultured umbilical cord-derived mesenchymal stem cells.As intended,the patient's pain was relieved after treatment.Interestingly,an additional benefit was found in that the size of the cavity also decreased.After 2 years from the last treatment,the patient's cavity had almost completely disappeared and her syringomyelia was deemed cured.CONCLUSION Using uncultured umbilical cord-derived mesenchymal stem cells may be a new treatment alternative for syringomyelia.

Surgical treatment of congenital basilar invagination with different pathological characteristics: Report of 139 cases

Objective: To describe the different pathological characteristics of congenital basilar invaginations and discuss the surgical treatment of such cases. Methods: A total of 139 patients diagnosed with basilar invaginations underwent surgical treatment from 2008 to 2015. Based on Atul Goel's classification and simultaneous consideration of atlantoaxial dislocation or syringomyelia,the cases were subdivided into four groups. Individualized posterior surgical decompression and/or atlantoaxial reset procedures were performed to correct atlantoaxial dislocation,decompress the brain stem,or resolve syringomyelia. The indications and critical points of each procedure were documented. Results: All 139 patients were surgically treated; 27 patients(19.4%) had underwent at least one decompression surgery previously. On an average,there was gratifying clinical improvement based on the Japanese Orthopaedic Association score analysis.One patient exhibited severe post-operative infection,and the fusion instrument was removed. One patient experienced fracture of internal fixation. Two patients exhibited persistent respiratory symptoms at early stages after the surgery. Four patients felt worse at the latest follow-up. There was no surgical mortality. The poor outcome/morbidity in this series was 5.8%(8/139). Conclusion: The different pathological image characteristics of congenital basilar invaginations based on the presence or absence of syringomyelia and/or atlantoaxial dislocation,reflected the pathological features of complicated basilar invaginations more accurately. Based on these features,different posterior decompression and/or reset procedures,combined with occipitocervical fusion and C1-2 fusion,could be tailored to different patients. These individualized surgeries could reduce surgical complications,decrease morbidity and mortality,and further promote positive outcomes.