Cerebellar Tonsillar Ectopia Research Articles

Idiopathic Intracranial Hypertension Induced Cervical Syringomyelia and Cerebellar Tonsillar Ectopia Reversed With Venous Sinus Stenting.

Idiopathic Intracranial Hypertension Induced Cervical Syringomyelia and Cerebellar Tonsillar Ectopia Reversed With Venous Sinus Stenting.

Increased hindbrain motion in Chiari I malformation patients measured through 3D amplified MRI (3D aMRI)

Chiari Malformation type 1 (CM-I) is a neurological disorder characterized by morphological defects including excessive cerebellar tonsillar ectopia and associated manifestations. We used 3D amplified MRI on a cohort of healthy and CM-I subjects to investigate the brain’s intrinsic motion, its association with the morphology and patient’s symptomatology, and surgical outcomes. We observed that the regional brain motion in CM-I was significantly higher than that of the healthy subjects, with anterior-posterior (AP) and superior-inferior (SI) displacements in cerebellar tonsils and medulla having the highest differences between the healthy and CM-I (∼45%–∼73% increased motion in the CM-I group). Interestingly, we found the ratio of neural tissue in the foramen magnum to be directly correlated with the SI tonsillar motion (r=0.58). Tonsillar herniation was directly correlated with the AP motion of the tonsils (r=0.61), and AP and medial-lateral (ML) motions of the medulla (r=0.66, and r=0.57). Subjects with higher tonsillar ML motion prior to surgery showed improved outcome (p=0.03, and AUC=0.95). Although we did not observe a significant correlation between the brains motion and morphometrics on the CM-I symptoms (perhaps due to our small sample size), illustrative cases increase our hope for the development of a future tool based on brain biomechanics.

Chromosome Xp22.3 deletion syndrome with X-linked ichthyosis, Kallmann syndrome, short stature, generalized epilepsy, hearing loss, attention deficit hyperactivity disorder, and intellectual disability – A rare report with review of literature

Chromosome Xp22.3 deletion syndrome is a very rare contiguous gene deletion syndrome with variable phenotype due to the deletion of genes from the distal short arm of the X chromosome (Xp), including the short-stature homeobox (SHOX), anosmin-1 (ANOS1), arylsulfatase (ARSL), neuroligin-4 (NLGN4), and steroid sulfatase (STS) genes. We have reviewed the available literature on the chromosome Xp22.3 deletion syndrome. A 10-year-old boy presented with global developmental delay, generalized epilepsy, decreased hearing, and hyperactivity. He had no significant family history. Examination revealed microcephaly, short stature, and dry and scaly skin lesions on the trunk. He had thick arched eyebrows, a depressed nasal bridge, a long philtrum, high arched palate, retrognathia, brachytelephalangy, brachymetatarsia, and mild scoliosis. Brainstem-evoked response audiometry testing revealed moderate hearing loss. Magnetic resonance imaging showed cerebellar tonsillar ectopia. Clinical exome sequencing revealed a likely pathogenic contiguous deletion (~8.10 Mb) spanning genomic location chrX:g.(_630898)_(8732037_)del encompassing ANOS1, ARSL, NLGN4X, SHOX, and STS genes. We have reviewed the available literature for reported associations of Chromosome Xp22.3 deletion syndrome and report a novel association of X-linked ichthyosis, Kallmann syndrome, global developmental delay, short stature, bilateral hearing loss, generalized epilepsy, attention deficit hyperactivity disorder, and intellectual disability.

Evaluation and Treatment of Patients with Small Posterior Cranial Fossa and Chiari Malformation, Types 0 and 1.

The diagnosis of Chiari I malformation is straightforward in patients with typical signs and symptoms of Chiari I malformation and magnetic resonance imaging (MRI) confirming ≥5 mm of cerebellar tonsillar ectopia, with or without a syrinx. However, in many cases, Chiari I malformation is discovered incidentally on MRI to evaluate global headache, cervical radiculopathy, or other conditions. In those cases, the clinician must consider if cerebellar tonsillar ectopia is related to the presenting symptoms. Surgical decompression of the cerebellar tonsils and foramen magnum in patients with symptomatic Chiari I malformation effectively relieves suboccipital headache, reduces syrinx distension, and arrests syringomyelia progression. Neurosurgeons must avoid operative treatments decompressing incidental tonsillar ectopia, not causing symptoms. Such procedures unnecessarily place patients at risk of operative complications and tissue injuries related to surgical exploration. This chapter reviews the typical signs and symptoms of Chiari I malformation and its variant, Chiari 0 malformation, which has <5 mm of cerebellar tonsillar ectopia and is often associated with syringomyelia. Chiari I and Chiari 0 malformations are associated with incomplete occipital bone development, reduced volume and height of the posterior fossa, tonsillar ectopia, and compression of the neural elements and cerebrospinal fluid (CSF) pathways at the foramen magnum. Linear, angular, cross-sectional area, and volume measurements of the posterior fossa, craniocervical junction, and upper cervical spine identify morphometric abnormalities in Chiari I and Chiari 0 malformation patients. Chiari 0 patients respond like Chiari I patients to foramen magnum decompression and should not be excluded from surgical treatment because their tonsillar ectopia is <5 mm. The authors recommend the adoption of diagnostic criteria for Chiari 0 malformation without syringomyelia. This chapter provides updated information and guidance to the physicians managing Chiari I and Chiari 0 malformation patients and neuroscientists interested in Chiari malformations.

Papilledema and Chiari I in childhood: case report

Introduction: Chiari malformation type I (CM-I) is a condition characterized by an abnormal craniocervical transition whose main finding is cerebellar tonsillar ectopia of &gt; 5 mm below the foramen magnum. The main clinical manifestations are occipital headache, truncal ataxia, corticospinal tract dysfunctions, and scoliosis.&#x0D; Objective: The scope of this article is to report a rare case of papilledema and visual impairment in a child diagnosed with CM-I.&#x0D; Methods/case presentation: Presentation of the case of an 8-year-old child with difficulty in performing school activities due to visual blurring in the 3 days prior to hospitalization. She was taken by her parents to the ophthalmologist who identified bilateral papilledema and was urgently referred to the pediatric emergency unit. She underwent magnetic resonance imaging of the brain and CM-I was identified. She underwent urgent surgical posterior cranial fossa decompression and progressed to complete visual improvement, confirmed by ophthalmological examination.&#x0D; Conclusion: Papilledema may be the initial clinical manifestation of CM-I in children and urgent surgical decompression of the posterior cranial fossa may prevent or even reverse the visual impairment.

Abstract #1400950: Chiari I Malformation with Concomitant Nonfunctioning Pituitary and Adrenal Tumors

Chiari I malformation (CM1) is a rare finding with an incidence ranging from 3.3 to 8.2 per 100000. CM1 has been described with growth hormone secreting pituitary adenomas, and with EPAS1 gain-of-function mutation syndrome with multiple paragangliomas/pheochromocytomas, somatostatinoma, and polycythemia. There is only one case report in the literature describing a nonfunctional pituitary adenoma with CM1. We describe the first reported case of a patient with CM1 with concomitant nonfunctional pituitary and adrenal incidentalomas. A 45-year-old female with history of diet-controlled diabetes and HTN presented with a two-week history of bilateral upper extremity weakness and paresthesia, along with gait instability. She had reduced motor power in the upper extremities on physical exam. MRI cervical spine demonstrated a cervicothoracic syrinx, cerebellar tonsillar ectopia consistent with CM1. MRI brain showed diffuse enlargement of the pituitary gland measuring 16 x 14 x 13 mm bulging into the suprasellar cistern and minimally abutting the inferior aspect of the optic chiasm. MRI lumbar spine revealed a left adrenal gland nodule measuring 1.5 x 2.0 cm. Endocrine hormonal evaluation showed normal prolactin, follicle stimulating and luteinizing hormone, estradiol, free T3, free T4, and IGF-I levels. Aldosterone level was high in supine position with normal plasma renin activity initially with normal levels on repeat testing. Plasma free metanephrine, normetanephrine, testosterone levels were also normal. Patient was started on dexamethasone in anticipation of surgery. Patient underwent suboccipital craniectomy, C1 laminectomy, coagulation of cerebellar tonsils and expansile duraplasty for CM1. Patient did well postoperatively and dexamethasone was tapered off. Postoperative follow up after patient had been off steroids for three weeks showed normal levels of all pituitary and adrenal hormones, including normal dexamethasone suppression test. While CM1 is a rare finding, pituitary adenomas are relatively common. In cases of concomitant occurrence of CM1 and growth hormone secreting pituitary adenoma, over-secretion of growth hormone has been proposed as a mechanism to precipitate symptoms of CM1 by causing hypertrophy of connective and ligamentous tissue in the skull base and of the cranio-cervical canal. Our patient had normal IGF-1 levels with a nonfunctional pituitary adenoma raising the question whether there is some other underlying mechanism, possibly a genetic predisposition, that contributed to the concomitant occurrence of CM1 with pituitary and adrenal tumors. Whether these tumors become functional in the future remains to be seen.

RF26 | PSAT109 The Prevalence of Abnormalities in Cranial MRIs in Children with Short Stature Prior to Growth Hormone Therapy

Abstract Background MRIs of the brain in patients with short stature have shown a number of abnormalities. Some of these radiological findings can have clinical significance. Here we have looked at MRI results in such a population. Objective To review the value and significance of the prevalence of all abnormal MRI findings of children with short stature who are to undergo growth hormone therapy (GHT). Materials and methods This study involved a retrospective review of MRI findings in all children prescribed GHT within a pediatric health network's database from Jan 2020 to Aug 2021. Post-gadolinium contrast enhanced brain and pituitary MRIs utilizing 2 mm slices were used to calculate pituitary volume. Pituitary volume was calculated using the ellipsoid formula (LxWxH/2). Pediatric patients diagnosed with non-acquired GHD or ISS, with MRIs having been performed between Jan 2020 and Aug 2021 and having been prescribed GHT by Aug 2021 were included in this study. Patients who experienced other endocrine abnormalities such as SGA, Turner Syndrome, and Noonan Syndrome were excluded. Patients with obstruction of sellar and parasellar religion due to movement artifacts or magnetic interference on their MRIs were also excluded. Results Of one hundred and twelve patients found, eighty one met criteria for inclusion in this study. Of the eighty one MRIs reviewed, twenty eight children, 34.6%, had normal pituitary anatomy and fifty three, 65.4%, had a pituitary abnormality. Out of the fifty three with a pituitary abnormality, forty three subjects, 81.1%, were determined to have a small pituitary volume, including significant pituitary hypoplasia. Ten subjects (18.9%) had an enlarged pituitary volume (pituitary hyperplasia). Of these ten patients who had an enlarged pituitary volume, eight were pubertal (80%). Nine children with a pituitary abnormality (16.9%) had additional structural anomalies on their MRIs. One had a small left frontal developmental venous anomaly. Two had Rathke's cleft cysts. Two had pars intermedia cysts. One had a small right parietal developmental venous anomaly. One had a small left parietal developmental venous anomaly. One had a left cerebellar tonsillar ectopia bordering on chiari malformation (.5 mm away on the coronal plane). One had a small lobulation (semi-bulbous projection) of the anterior pituitary gland, superior and anterior to the infundibular stalk. Conclusion Prevalence of brain abnormalities in children with short stature who are to undergo GHT is significant and warrants MRI evaluations in these subjects. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Monday, June 13, 2022 12:58 p.m. - 1:03 p.m.

Differentiation of Chiari malformation type 1 and spontaneous intracranial hypotension using objective measurements of midbrain sagging.

Chiari malformation type 1 (CM-1) and spontaneous intracranial hypotension (SIH) are causes of headache in which cerebellar tonsillar ectopia (TE) may be present. An accurate method for differentiating these conditions on imaging is needed to avoid diagnostic confusion. Here, the authors sought to determine whether objective measurements of midbrain morphology could distinguish CM-1 from SIH on brain MRI. This is a retrospective case-control series comparing neuroimaging in consecutive adult subjects with CM-1 and SIH. Measurements obtained from brain MRI included previously reported measures of brain sagging: TE, slope of the third ventricular floor (3VF), pontomesencephalic angle (PMA), mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter (DOI). Clivus length (CL), an indicator of posterior fossa size, was also measured. Measurements for the CM-1 group were compared to those for the entire SIH population (SIHall) as well as a subgroup of SIH patients with > 5 mm of TE (SIHTE subgroup). Highly significant differences were observed between SIHall and CM-1 groups in the following measures: TE (mean ± standard deviation, 3.1 ± 5.7 vs 9.3 ± 3.5 mm), 3VF (-16.8° ± 11.2° vs -2.1° ± 4.6°), PMA (44.8° ± 13.1° vs 62.7° ± 9.8°), DOI (0.2 ± 4.1 vs 3.8 ± 1.6 mm), and CL (38.3 ± 4.5 vs 44.0 ± 3.3 mm; all p < 0.0001). Eight (16%) of 50 SIH subjects had TE > 5 mm; in this subgroup (SIHTE), a cutoff value of < -15° for 3VF and < 45° for PMA perfectly discriminated SIH from CM-1 (sensitivity and specificity = 1.0). DOI showed perfect specificity (1.0) in detecting SIH among both groups. No subjects with SIH had isolated TE without other concurrent findings of midbrain sagging. Measures of midbrain sagging, including cutoff values for 3VF and PMA, discriminate CM-1 from SIH and may help to prevent misdiagnosis and unnecessary surgery.

Feasibility of rapid spine magnetic resonance evaluation for spinal cord syrinx in the pediatric population.

This study investigates the feasibility of ultrafast fluid sensitive techniques for evaluation of pediatric spinal cord syrinx. Rapid imaging could obviate the need for sedation, which is often required for children undergoing lengthier standard spine imaging. Children undergoing standard spine imaging for Chiari malformation, suspected Chiari malformation, or syrinx were included. Patients who provided informed consent were imaged with rapid acquisition sagittal and axial T2 HASTE spine sequences in addition to standard spine imaging. Standard and rapid spine imaging were then reviewed separately by a pediatric neuroradiologist. The presence or absence of syrinx, syrinx diameter, and length were assessed. The degree of cerebellar tonsillar ectopia, conus position, and evaluation of the filum were also recorded. Seventy-six patients aged 1month to 18years (mean 7years) met the inclusion criteria. The sensitivity and specificity of rapid spine imaging for syrinx was 87.8% and 94.7% respectively. All syrinxes > 2.3mm in diameter were identified with the rapid spine sequences. There was no statistically significant difference between rapid and standard spine imaging in assessment of syrinx diameter or length. Compared with standard spine imaging, rapid spine sequences demonstrated a 100% sensitivity for low-lying conus and a 98.2% sensitivity for cerebellar tonsillar ectopia. The filum was identified on only 31.6% of the rapid spine studies. Rapid T2 imaging demonstrated a high sensitivity for the presence and extent of spinal cord syrinx and may provide an alternative to traditional, lengthier standard spine imaging in selected patients.

Population-Based Evaluation of Indirect Signs of Increased Intracranial Pressure.

The Mayo Clinic Study of Aging (MCSA) is a unique prospective study that systematically evaluates the normal aging population and includes many participants undergoing both MRI and lumbar puncture (LP). Using MCSA date, we aimed to determine the prevalence of indirect signs of raised intracranial pressure (ICP) on MRI and whether these correlate with LP opening pressure (OP). This is a large-scale study that evaluates how often indirect signs of increased ICP occur in a normal population. MCSA participants who had an MRI within 3 months of an LP with recorded OP were included in the study. MRIs were reviewed for indirect signs of raised ICP, including pituitary to sella (P/S) ratio, cerebellar tonsillar ectopia, and optic nerve sheath diameter (ONSD). These signs were evaluated for correlations with OP and influences from body mass index (BMI) and obstructive sleep apnea (OSA). Five hundred ninety-seven MCSA patients were identified who underwent both LP and MRI. Two hundred sixty (43.6%) were women. The median age was 70.7 years (range 32.6-92.7). Median OP was 152 mm H2O (range 60-314 mm H2O), with 91 (15.2%) participants having an OP ≥ 200 mm H2O. Empty or partially empty sella was seen in 81 (12.8%) of the cohort. The P/S ratio decreased with increasing OP (r = -0.3, P < 0.001). There was a weak correlation between OP and average ONSD (r = 0.184, P = 0.01), which was no longer significant when accounting for age, gender, and BMI (partial r2 = 0.014, P = 0.097). There was no correlation between OP and cerebellar tonsillar ectopia. OSA was associated with increased ONSD (P = 0.004), but this did not remain statistically significant after accounting for age, gender, and BMI (P = 0.085). Smaller pituitary gland size correlated with increasing OP. This suggests that ICP is a continuum with some normal individuals demonstrating asymptomatic radiologic signs of raised ICP.

Imaging and health metrics in incidental cerebellar tonsillar ectopia: findings from the Adolescent Brain Cognitive Development Study (ABCD).

Incidental cerebellar tonsillar ectopia (ICTE) that meets the radiographic criterion for Chiari malformation type I (CMI) is an increasingly common finding in the clinical setting, but its significance is unclear. The present study examined posterior cranial fossa (PCF) morphometrics and a broad range of health instruments of pediatric ICTE cases and matched controls extracted from the Adolescent Brain Cognitive Development (ABCD) dataset. One-hundred-six subjects with ICTE and 106 matched controls without ICTE were identified from 11,411 anatomical MRI of healthy screened pediatric subjects from the ABCD project. Subjects were matched by sex, age, body mass index, race, and ethnicity. Twenty-two brain morphometrics and 22 health instruments were compared between the two groups to identify unrecognized CMI symptoms and assess the general health impact of ICTE. Twelve and 15 measures were significantly different between the ICTE and control groups for females and males, respectively. Notably, for females, the anterior CSF space was significantly smaller (p = 0.00005) for the ICTE group than controls. For males, the clivus bone length was significantly shorter (p = 0.0002) for the ICTE group compared to controls. No significant differences were found among the 22 health instruments between the two groups. This study demonstrated that pediatric ICTE subjects have similar PCF morphometrics to adult CMI. ICTE alone did not appear to cause any unrecognized CMI symptoms and had no impact on the subjects' current mental, physical, or behavioral health. Still, given their cranial and brain morphology, these cases may be at risk for adult-onset symptomatic CMI.

Occipital-Cervical Fusion and Ventral Decompression in the Surgical Management of Chiari-1 Malformation and Syringomyelia: Analysis of Data From the Park-Reeves Syringomyelia Research Consortium.

Occipital-cervical fusion (OCF) and ventral decompression (VD) may be used in the treatment of pediatric Chiari-1 malformation (CM-1) with syringomyelia (SM) as adjuncts to posterior fossa decompression (PFD) for complex craniovertebral junction pathology. To examine factors influencing the use of OCF and OCF/VD in a multicenter cohort of pediatric CM-1 and SM subjects treated with PFD. The Park-Reeves Syringomyelia Research Consortium registry was used to examine 637 subjects with cerebellar tonsillar ectopia≥5mm, syrinx diameter≥3mm, and at least 1 yr of follow-up after their index PFD. Comparisons were made between subjects who received PFD alone and those with PFD+OCF or PFD+OCF/VD. All 637 patients underwent PFD, 505 (79.2%) with and 132 (20.8%) without duraplasty. A total of 12 subjects went on to have OCF at some point in their management (PFD+OCF), whereas 4 had OCF and VD (PFD+OCF/VD). Of those with complete data, a history of platybasia (3/10, P=.011), Klippel-Feil (2/10, P=.015), and basilar invagination (3/12, P<.001) were increased within the OCF group, whereas only basilar invagination (1/4, P<.001) was increased in the OCF/VD group. Clivo-axial angle (CXA) was significantly lower for both OCF (128.8± 15.3°, P=.008) and OCF/VD (115.0± 11.6°, P=.025) groups when compared to PFD-only group (145.3± 12.7°). pB-C2 did not differ among groups. Although PFD alone is adequate for treating the vast majority of CM-1/SM patients, OCF or OCF/VD may be occasionally utilized. Cranial base and spine pathologies and CXA may provide insight into the need for OCF and/or OCF/VD.

Clinical pitfalls in the diagnosis of segmental overgrowth syndromes: a child with the c.2740G\u2009>\u2009A mutation in PIK3CA gene

BackgroundOvergrowth syndromes are known as a heterogeneous group of conditions characterized by a generalized or segmental, symmetric or asymmetric, overgrowth that may involve several tissues. These disorders, which present a wide range of phenotypic variability, are often caused by mosaic somatic mutations in the genes associated with the PI3K/AKT/mTOR cellular pathway, a signaling cascade that plays a key role in cellular growth. Overgrowth syndromes are frequently misdiagnosed. Given that they are also associated to an increased oncologic risk, it is important to distinguish the clinical characteristic of these disorders since the first months of life.Case presentationWe report the case of a seven-year-old male child with macrocephaly and right lateralized overgrowth, reported from birth. The patient arrived to our attention after an initial diagnosis of isolated benign macrocephaly was formulated at the age of 12 months. Afterwards, the child presented a moderate intellectual disability and pain episodes at right lower limb. We repeated a brain Magnetic Resonance Imaging that revealed ventriculomegaly, cerebellar tonsillar ectopia, a markedly thick corpus callosum, and white matter abnormalities. The diagnosis of segmental overgrowth syndrome was formulated according to the clinical presentation and confirmed by the finding of the variant c.2740G > A in the gene PIK3CA presented in somatic mosaicism.ConclusionsOur patient is the first children with the c.2740G > A variant in PIK3CA gene reported in Italy. We underline the importance of the genotype-phenotype correlation in the diagnostic process of overgrowth syndromes and emphasize the strict correlation between the mutation c.2740G > A in the PIK3CA gene and the Megalencephaly-Capillary Malformation syndrome phenotype.

Effectiveness of modified dural incision to preserve the patency of the occipital sinus in foramen magnum decompression for a patient with Chiari malformation type I.

Background:Foramen magnum decompression (FMD) has been acknowledged as a standard surgical procedure for symptomatic patients with Chiari malformation type I (CM-I). However, even if dural incision is necessary during FMD, the procedure of cutting off the occipital sinus has not been regarded as a safe option.Case Description:A 27-year-old woman with intractable occipital headache was diagnosed with CM-I without syringomyelia. Preoperative examination revealed a large oblique occipital sinus on her right side. During the first FMD, the dura mater was not incised to preserve the occipital sinus. However, her headache was not relieved with painkillers and cerebellar tonsillar ectopia remained. During the second FMD, two dural incisions were made, while preserving the occipital sinus patency. The dural patch was made using an autologous fascia for both dural incisions. Postoperatively, headache was completely resolved immediately, and cerebellar tonsil was elevated without any complication.Conclusion:This dural incision, which is a modification of the method introduced by Pritz, would be a useful FMD option for patients of CM-I with dominant occipital sinus, which would lead to the serious neurological sequelae if the sinus flow is disturbed.

Brain magnetic resonance imaging findings in children with headache.

The aim was to describe the findings on magnetic resonance imaging (MRI) in children with headache. Retrospective review of the medical records of patients who were admitted to our pediatric outpatient neurology clinics with the complaint of headache between January 2013 and December 2014. A total of 478 patients (273 female, 205 male) were admitted with the complaint of headache. The types of headache were migraine in 218 (45.6%), tension-type in 159 (33.3%), secondary in 39 (8.2%) and unspecified headaches in 62 (13%) patients. Brain MRI was performed in 407 (85%) patients and revealed cerebral abnormalities in 128 (31.4%) patients; 5 patients had cerebral abnormalities relevant with headache, including tumors. Amongst the others 123 patients, the most common findings were 42 cases (10%) of nonspecific white matter abnormalities, 17 cases (4%) of enlarged perivascular spaces, 17 cases (4%) of arachnoid cyst, 16 cases (3.9%) of asymmetric ventricles, 12 cases (2.9%) with Chiari type I and cerebellar tonsillar ectopia. Also, 17 (4.1%) patients had extra-cerebral MRI abnormalities including sinusitis, mucosal thickening and retention cysts of sinuses. In this study, the contribution of brain MRI in the diagnosis and management of the children with headache was still low.

Brain MR Imaging Findings and Associated Outcomes in Carriers of the Reciprocal Copy Number Variation at 16p11.2.

Purpose To identify developmental neuroradiologic findings in a large cohort of carriers who have deletion and duplication at 16p11.2 (one of the most common genetic causes of autism spectrum disorder [ASD]) and assess how these features are associated with behavioral and cognitive outcomes. Materials and Methods Seventy-nine carriers of a deletion at 16p11.2 (referred to as deletion carriers; age range, 1-48 years; mean age, 12.3 years; 42 male patients), 79 carriers of a duplication at 16p11.2 (referred to as duplication carriers; age range, 1-63 years; mean age, 24.8 years; 43 male patients), 64 unaffected family members (referred to as familial noncarriers; age range, 1-46 years; mean age, 11.7 years; 31 male participants), and 109 population control participants (age range, 6-64 years; mean age, 25.5 years; 64 male participants) were enrolled in this cross-sectional study. Participants underwent structural magnetic resonance (MR) imaging and completed cognitive and behavioral tests. MR images were reviewed for development-related abnormalities by neuroradiologists. Differences in frequency were assessed with a Fisher exact test corrected for multiple comparisons. Unsupervised machine learning was used to cluster radiologic features and an association between clusters and cognitive and behavioral scores from IQ testing, and parental measures of development were tested by using analysis of covariance. Volumetric analysis with automated segmentation was used to confirm radiologic interpretation. Results For deletion carriers, the most prominent features were dysmorphic and thicker corpora callosa compared with familial noncarriers and population control participants (16%; P < .001 and P < .001, respectively) and a greater likelihood of cerebellar tonsillar ectopia (30.7%; P < .002 and P < .001, respectively) and Chiari I malformations (9.3%; P < .299 and P < .002, respectively). For duplication carriers, the most salient findings compared with familial noncarriers and population control participants were reciprocally thinner corpora callosa (18.6%; P < .003 and P < .001, respectively), decreased white matter volume (22.9%; P < .001, and P < .001, respectively), and increased ventricular volume (24.3%; P < .001 and P < .001, respectively). By comparing cognitive assessments to imaging findings, the presence of any imaging feature associated with deletion carriers indicated worse daily living, communication, and social skills compared with deletion carriers without any radiologic abnormalities (P < .005, P < .002, and P < .004, respectively). For the duplication carriers, presence of decreased white matter, callosal volume, and/or increased ventricle size was associated with decreased full-scale and verbal IQ scores compared with duplication carriers without these findings (P < .007 and P < .004, respectively). Conclusion In two genetically related cohorts at high risk for ASD, reciprocal neuroanatomic abnormalities were found and determined to be associated with cognitive and behavioral impairments. © RSNA, 2017 Online supplemental material is available for this article.

Arnold Chiari Malformation - A hospital based autopsy study

In Arnold Chiari II malformation the cerebellar tonsils are displaced inferiorly through the Foramen Magnum into the upper cervical spinal canal. It is a complex anomaly with skull, dura, brain, spine and cord manifestations. This study was conducted on 400 fetuses obtained from department of Obstetrics and Gynaecology, Government Medical College and Hospital, Chandigarh. Arnold Chiari malformation was noted in 10 out of 300 (3.33%) fetal autopsy cases. All cases were associated with meningomylocele. In our study we found that 7 cases were showing cerebellar tonsilla rectopia and 3case of type II. Arnold Chiari Malformations can be prevented by preconceptional folic acid and Vitamin B 12 supplementation.

Sagittal MRI often overestimates the degree of cerebellar tonsillar ectopia: a potential for misdiagnosis of the Chiari I malformation.

We hypothesized that by using coronal MRI, Chiari I malformation could be more precisely diagnosed, would provide simple anatomic landmarks, would provide information regarding asymmetry of hindbrain herniation, and would be a better method for analyzing the tonsillar herniation postoperatively when the opisthion has been removed. Fifty consecutive pediatric patients diagnosed with Chiari I malformation had comparison between the measurements of their caudally descended cerebellar tonsils on midsagittal and coronal MRI images. On MRI coronal imaging, tonsillar asymmetry was found in 48 patients. Maximal left tonsillar descent was 20.9mm, and maximal right tonsillar descent was 17.4mm. On MRI sagittal imaging, tonsillar descent ranged from 5 to 27.4mm. Fifty-eight% of patients had syringomyelia. Five patients (10%) on coronal MRI were found to have both cerebellar tonsils that were less than 3mm below the foramen magnum. However, all of these patients had greater than 3mm of tonsillar ectopia on sagittal imaging. Nineteen patients (38%) on coronal MRI were found to have one of the cerebellar tonsils that were less than 3mm below the foramen magnum. Similarly, each of these had greater than 3mm of tonsillar ecotpia as measured on midsagittal MRI. Also, based on these findings, Chiari I malformation is almost always an asymmetrical tonsillar ectopia. Sagittal MRI overestimates the degree of tonsillar ectopia in patients with Chiari I malformation. Misdiagnosis may occur if sagittal imaging alone is used. The cerebellar tonsils are paramedian structures, and this should be kept in mind when interpreting midline sagittal MRI.

Comment on: "sagittal MRI often overestimates the degree of cerebellar tonsillar ectopia: a potential for misdiagnosis of the Chiari I malformation", by R. Shane Tubbs et al.

Comment on: "sagittal MRI often overestimates the degree of cerebellar tonsillar ectopia: a potential for misdiagnosis of the Chiari I malformation", by R. Shane Tubbs et al.

Anatomical Origin of Abnormal Somatosensory-Evoked Potential (SEP) in Adolescent Idiopathic Scoliosis With Different Curve Severity and Correlation With Cerebellar Tonsillar Level Determined by MRI.

A prospective cohort study. The aim of this study was to compare the somatosensory-evoked potential (SEP) findings of adolescent idiopathic scoliosis (AIS) subjects of different curve severity with age- and gender-matched controls and to evaluate any correlation between the site of the SEP abnormality with cerebellar tonsillar level measured by magnetic resonance imaging (MRI). Our previous studies showed that a higher percentage of SEP abnormality and cerebellar tonsillar ectopia was present in AIS patients than in normal controls. However, the relationship between the anatomical site of the neurophysiological abnormality and the severity in AIS patients has not been defined. SEP measurement was conducted on 91 Chinese AIS girls with major right thoracic curve of different curve severity (mild, moderate, severe) and 49 matched normal controls. Waveform characteristics (latency and amplitude) were compared among groups. Specific location of SEP abnormality was identified from tibial to cortical levels. Cerebellar tonsillar ectopia was defined by the previously established reference line between basion and opisthion on MRI. Significant prolonged P37 latency was found on the right side between severe AIS patients and normal controls, while increased inter-side P37 latency difference was found between severe versus moderate, and severe versus normal controls. Cerebellar tonsillar ectopia was detected in 27.3% of severe group, 5.8% to 6.7% in mild and moderate group, but none in normal controls. Abnormal SEP occurred superior to C5 region in all surgical (severe) patients, of whom 58% had cerebellar tonsillar ectopia. AIS patients showed significant prolonged latency and increased latency difference on the side of major curvature. The incidence of SEP abnormality increased with curve severity and occurred above the C5 level. The findings suggested that there was a subgroup of progressive AIS with subclinical neurophysiological dysfunction, associated with underlying neuromorphological abnormalities, which were only detectable by SEP and MRI. 3.