Syringomyelia Associated with Chiari 1 Malformation in Adults: Positive Outcome Predictors after Posterior Fossa Decompression with Duraplasty.

BACKGROUND: Syringomyelia (Syr) in patients with Chiari 1 malformation (CM1) may be attributable to abnormal dynamics of cerebrospinal fluid (CSF) in the upper cervical segment; fourth ventricle enlargement has been reported in association with a worse clinical and radiological presentation, independently of the posterior fossa volume. In this study, we analyzed presurgery hydrodynamic markers to evaluate if their changes could be associated with clinical and radiological improvement after posterior fossa decompression and duraplasty (PFDD). As a primary endpoint, we aimed to correlate improvement in the fourth ventricle area with positive clinical outcomes. METHODS: In total, in this study, we enrolled 36 consecutive adults with Syr and CM1 who were followed by a multidisciplinary team. All the patients were prospectively evaluated with clinical scales and neuroimaging, including CSF flow, the fourth ventricle area, and the Vaquero Index by using a phase-contrast MRI before (T0) and after surgical treatment (T1-Tlast, with a range of 12-108 months). The CSF flow at the craniocervical junction (CCJ), the fourth ventricle area, and the Vaquero Index changes were statistically analyzed and compared to the clinical and quality of life improvement after surgery. The good outcome prediction ability of presurgical radiological variables was tested. RESULTS: Surgery was associated with positive clinical and radiological outcomes in more than 90% of cases. The fourth ventricle area significantly reduced after surgery (T0-Tlast, p = 0.0093), but no significant associations with clinical improvement were found. The presurgical presence of CSF flow at the CCJ was able to predict a good outcome (AUC = 0.68, 95% CI 0.50-0.87 and LH+ = 2.1, IC 95% 1.16-3.07) and was also significantly associated with post-surgical pain relief (rho = 0.61 and p = 0.0144). CONCLUSIONS: Presurgery CSF flow at the CCJ is proposed as a radiological marker with the ability to predict a positive outcome after PFDD in adults with syringomyelia and CM1. Measurements of the fourth ventricle area could be useful additional information for evaluating surgical long-term follow-up; further experience on larger cohorts is required to better define the prognostic yield of this radiological parameter.

Migraine in Chiari 1 Malformation: a cross-sectional, single centre study.

In Chiari 1 Malformation (CM1) the most frequent symptom is exertional headache, but other headache types have been reported, such as migraine. This cross-sectional study is aimed to examine the prevalence of migraine in a group of CM1 headache patients and to compare clinical-demographic characteristics between migraine and non-migraine patients. 427 adults were enrolled at the multidisciplinary Chiari Center in Torino. 230 headache patients were classified, based on radiological criteria. Frequencies (absolute/percentage values) were calculated in the whole sample for: migraine presence (with and without aura), gender, age, radiologic phenotypes and headache clinical characteristics. The association between CM1 diagnosis and headache characteristics (independent variables) and migraine diagnosis (dependent variable) was estimated by logistic regression models. Seventy-eight patients (67 females) out of 230 presenting headache had a migraine (34%), 44/78 (56%) with aura; in 58/78 (74%) migraine was comorbid with secondary headache attributable to CM1. Migraine prevalence in patients with isolated CM1 (52/120, 43.3%) was higher (p = 0.0016) than in all the other patients (26/110, 23.6%). Although migraine was prevalent in females (86%; 6:1 female:male ratio), age classes and gender were not risk factors for migraine at multivariate analysis, while migraine was associated with isolated CM1 phenotype (OR = 2.6). This study shows a high prevalence of migraine in CM1 patients and a significant association between migraine and isolated CM1. In patients with radiological evidence of CM1, particularly in the absence of neurological signs, a careful headache clinical characterization, according to the International Headache Society criteria, may be advised.

Diagnosis and treatment of Chiari malformation and syringomyelia in adults: international consensus document.

BACKGROUND: Syringomyelia and Chiari malformation are classified as rare diseases on Orphanet, but international guidelines on diagnostic criteria and case definition are missing. AIM OF THE STUDY: to reach a consensus among international experts on controversial issues in diagnosis and treatment of Chiari 1 malformation and syringomyelia in adults. METHODS: A multidisciplinary panel of the Chiari and Syringomyelia Consortium (4 neurosurgeons, 2 neurologists, 1 neuroradiologist, 1 pediatric neurologist) appointed an international Jury of experts to elaborate a consensus document. After an evidence-based review and further discussions, 63 draft statements grouped in 4 domains (definition and classification/planning/surgery/isolated syringomyelia) were formulated. A Jury of 32 experts in the field of diagnosis and treatment of Chiari and syringomyelia and patient representatives were invited to take part in a three-round Delphi process. The Jury received a structured questionnaire containing the 63 statements, each to be voted on a 4-point Likert-type scale and commented. Statements with agreement <75% were revised and entered round 2. Round 3 was face-to-face, during the Chiari Consensus Conference (Milan, November 2019). RESULTS: Thirty-one out of 32 Jury members (6 neurologists, 4 neuroradiologists, 19 neurosurgeons, and 2 patient association representatives) participated in the consensus. After round 2, a consensus was reached on 57/63 statements (90.5%). The six difficult statements were revised and voted in round 3, and the whole set of statements was further discussed and approved. CONCLUSIONS: The consensus document consists of 63 statements which benefited from expert discussion and fine-tuning, serving clinicians and researchers following adults with Chiari and syringomyelia.

Clinical diagnosis-part I: what is really caused by Chiari I.

PURPOSE: Chiari malformation is a group of congenital malformations involving the brainstem, cerebellum, and upper spinal cord, frequently identified in both young adults and in children. Chiari I malformation (CM1), classically defined as a caudal displacement of the cerebellar tonsils through the foramen magnum into the spinal cord, is the most common clinical type. A syringomyelia can be associated at the time of the diagnosis or appear secondarily and manifest with medullary symptoms. The aim of this paper is to update the knowledge on clinical manifestations specifically related to Chiari I malformation with or without syringomyelia in the pediatric population. METHODS: Current literature with focus on relevant clinical pediatric issues is reviewed and discussed, comparing with those related to adults; we include the results of a 10-year single-center experience on 600 CM1 patients. RESULTS AND CONCLUSIONS: Herniation of the cerebellar tonsils may lead to significant clinical symptoms, including neck and cervical pain, short-lasting occipital "cough" headache, dizziness, and gait impairment; in children younger than 3 years, oropharyngeal symptoms are prevalent (sleep apnea, feeding problems) whereas in those older than 3 years, a higher incidence of cough headache and scoliosis is reported. CM1 clinical features, both in children and in adults, have in common the presence of anatomical deformities of the brainstem and cerebellum. Clinical myelopathy (sensory/autonomic disorders, motor weakness) can result from direct compression of the cervical spinal cord by the herniated cerebellar tonsils or can be due to the presence of a syrinx, reported in association with Chiari I between 35 and 75% of pediatric patients. Similarly, in our series (440 females, 160 males, 98% > 18 years), syringomyelia associated with Chiari I was ranging from 40 to 60% (respectively in asymptomatic and symptomatic groups); headache was reported in 65%. Sensory disturbances (48%), cranial nerve deficits (45%), motor weakness (32%), and autonomic disorders (35%) were the most frequent neurological signs in our cohort. In Chiari I malformation, cervical pain and occipital cough headache are the most characteristic presenting symptoms, both in old children and in adults; however, headache is often multifactorial, and CM1 patients can report a wide variety of non-specific symptoms and signs. Clinical diagnostic CM1 criteria, shared at the national and international level, are recommended with the aim to avoid consequent controversies on diagnosis and on surgical decision making.