Malformations of the craniocervical junction (Chiari type I and syringomyelia: classification, diagnosis and treatment)

Not all cases of nyctalopia are benign: Unusual and serendipitous presentation of Arnold-Chiari Type 1 malformation at a Pediatric Tertiary Care Center

The Arnold-Chiari Type 1 malformation (CM1) is a rare congenital abnormality characterized by ectopia or caudal herniation of the cerebellar tonsils through the foramen magnum into the cervical spine, resulting in crowding at the craniocervical junction. It seldom presents in childhood with symptoms and a normal neurological examination. More typically, CM1 presents in young adult women with neurological symptoms including a headache, cervical pain, cranial nerve palsies, neurosensory deficit, and ataxia. Ocular manifestations associated with Chiari I include third and sixth cranial nerve paresis and convergence/divergence abnormalities. Papilledema is a rare manifestation of Chiari I with a clinical presentation often similar to that of idiopathic intracranial hypertension. To underscore this noteworthy complication, the authors report a case of an 8-year-old boy who presented with nyctalopia and suboccipital headaches, but was diagnosed serendipitously as a case of papilledema due to Chiari I malformation.

Correlation of clivoaxial angle to skeletal malocclusions: A prescreening for future risk of neurodegenerative disorders

Objectives

To find out if there exists any correlation between clivoaxial angle (CXA) and skeletal malocclusions.

Materials

and Methods: Lateral cephalograms of 33 filipino patients equally divided in three types of skeletal malocclusions were traced, and cephalometric parameters CXA, BaSN, ANB, SNMPA, FMA, MMPA, and Y-axis were traced. Data underwent bivariate correlation and curve estimation analysis in SPSS 17.0 statistical software at confidence interval of 95% and 0.05 significance level.

Results

A highly significant (P = 0.003) strong negative correlation was revealed in Class III patients between CXA and BaSN.

Conclusion

Class III patients seem to have higher chances of craniocervical junction anomalies and thus might be at risk of developing neurodegenerative disorders in future.

Bilateral vocal cord palsy causing stridor as the only symptom of syringomyelia and Chiari I malformation, a case report

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We present the case of a three year old female who had a long standing stridor, previously being incorrectly managed as asthma by family practitioner.

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She was found to have a bilateral vocal cord palsy causing her stridor, as a result of a large syrinx formation and Arnold Chiari malformation.

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We highlight the importance of MRI as a diagnostic tool in the evaluation of vocal cord palsy and stridor.

Introduction

Bilateral vocal cord palsy is a condition which has many causes (Gupta et al., 2012) [1]. Syringomyelia is an uncommon condition which describes the formation of fluid filled cavity, occupying the spinal cord (Chang, 2003) [2]. It rarely manifests itself as subacute onset of stridor.

Presentation of case

We present the case of a three year old female who presented for evaluation of her speech and language delay, when incidentally it was made note of her loud breathing which had previously been managed as bronchiolitis by her general practitioner. In hospital she was found to have a bilateral vocal cord palsy. Further investigation revealed a large syrinx as well as an associated Arnold Chiari 1 malformation, for which she required neurosurgical decompression.

Conclusion

Although uncommon, formation of a syrinx should be considered for patients who present with stridor and reiterates the importance of MRI as an important investigative tool of bilateral vocal cord palsy.

Cerebrospinal fluid disturbance in overweight women after occipitocervical decompression in Chiari malformation type I

BACKGROUND

Cerebrospinal fluid disturbance (CSFD) is a well-known complication after occipitocervical decompression (OCD) in patients with Chiari malformation type I (CMI). There is scarce data focusing on preoperative patients' factors predisposing to development of CSF disturbance. The aim of this study is to evaluate a prognostic value of some patients' factors in the prediction of CSFD after OCD in CMI patients.

MATERIALS AND METHODS

We undertook a 10-year (2003-2013) retrospective study of all OCD in patients with CMI performed at Sahlgrenska IC, Sahlgrenska University Hospital, Sweden. A total of 52 consecutive patients were obtained from the operation database and we excluded one patient who was previously diagnosed with normal-pressure hydrocephalus. Data regarding preoperative age, body mass index, gender, degree of tonsillar herniation and syrinx were registered. Development of CSFD after OCD was noted.

RESULTS

Of the 51 patients reviewed, six had CSFD after OCD and were managed using a form of CSF diversion procedure. All of the patients who developed CSFD were females. They had a mean body mass index of 32.3 compared to a mean of 24.3 in patients without CSFD (p = 0.0011). There was no difference between the two groups with regard to the other examined patient factors.

CONCLUSIONS

CSF diversion was needed in six consecutive adult Chiari malformation type I patients who underwent occipitocervical decompression. All patients with postoperative CSFD were female and their mean BMI was significantly higher than patients without this complication.

Longitudinal measurements of syrinx size in a rat model of posttraumatic syringomyelia

OBJECTIVE Syringomyelia pathophysiology is commonly studied using rodent models. However, in vivo studies of posttraumatic syringomyelia have been limited by the size of animals and lack of reliable noninvasive evaluation techniques. Imaging the rat spinal cord is particularly challenging because the spinal cord diameter is approximately 1-3 mm, and pathological lesions within the spinal cord parenchyma are even smaller. The standard technique has been histological evaluation, but this has its limitations. The aim of the present study was to determine whether syrinx size could be reliably measured using a preclinical high-field MRI animal system in a rat model of posttraumatic syringomyelia. METHODS The authors used an existing rat model of posttraumatic syringomyelia, which was created using a controlled pneumatic compression device to produce the initial spinal cord injury, followed by a subarachnoid injection of kaolin to produce arachnoiditis. T2-weighted MRI was performed on each animal using a 9.4-T scanner at 7, 10, and 13 weeks after injury. Animals were killed and syrinx sizes were calculated from in vivo MRI and histological studies. RESULTS MRI measurements of syrinx volume and length were closely correlated to histological measurements across all time points (Pearson product moment correlation coefficient r = ± 0.93 and 0.79, respectively). CONCLUSIONS This study demonstrates that high-field T2-weighted MRI can be used to measure syrinx size, and data correlate well with syrinx size measured using histological methods. Preclinical MRI may be a valuable noninvasive technique for tracking syrinx formation and enlargement in animal models of syringomyelia.

The Role of the Craniocervical Junction in Craniospinal Hydrodynamics and Neurodegenerative Conditions

The craniocervical junction (CCJ) is a potential choke point for craniospinal hydrodynamics and may play a causative or contributory role in the pathogenesis and progression of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, MS, and ALS, as well as many other neurological conditions including hydrocephalus, idiopathic intracranial hypertension, migraines, seizures, silent-strokes, affective disorders, schizophrenia, and psychosis. The purpose of this paper is to provide an overview of the critical role of the CCJ in craniospinal hydrodynamics and to stimulate further research that may lead to new approaches for the prevention and treatment of the above neurodegenerative and neurological conditions.

Chiari-like Malformation

Chiari-like malformation is a condition of the craniocervical junction in which there is a mismatch of the structures of the caudal cranial fossa causing the cerebellum to herniate into the foramen magnum. This herniation can lead to fluid buildup in the spinal cord, also known as syringomyelia. Pain is the most common clinical sign followed by scratching. Other neurologic signs noted are facial nerve deficits, seizures, vestibular syndrome, ataxia, menace deficit, proprioceptive deficits, head tremor, temporal muscle atrophy, and multifocal central nervous system signs. MRI is the diagnostic of choice, but computed tomography can also be used.

Acute Presentation of Chiari I Malformation with Hemiparesis in a Pediatric Patient

BACKGROUND

Chiari I malformation (CM-I) is defined by cerebellar tonsillar herniation through the foramen magnum. Patients typically present with chronic complaints, including headache, dizziness, and numbness, although there are few reports in the literature of pediatric patients presenting acutely with neurological deficit caused by CM-I. We report a child who presented acutely with hemiparesis and magnetic resonance imaging findings consistent with CM-I and spinal cord edema.

CASE DESCRIPTION

A 3-year old boy with normal development presented with difficulty walking and increased drooling. His mother stated he was running into objects and had balance issues for several days. Neurological examination showed ataxia with falling to the right after a few steps and weakness of the right arm and leg. His medical history was remarkable only for mild asthma, although he had recently been treated for an upper respiratory viral infection. Computed tomography of the head demonstrated no brainstem mass. Magnetic resonance imaging of the head and cervical spine showed tonsillar ectopia approximately 2 cm below the craniocervical junction with increased T2 signal in the spinal cord from C1 to C3 consistent with syringomyelia and cord edema. The patient underwent suboccipital craniectomy with removal of the posterior arch of C1 and dural patch graft. His postoperative course was unremarkable, with complete resolution of his symptoms at his 1-month follow-up visit.

CONCLUSIONS

This case highlights an unusual presentation of CM-I with neurological deficit related to spinal cord edema, possibly precipitated by the "water-hammer" effect of this patient's coughing fits. Providers should be aware of the acute presentations of CM-I.

Patient-reported Chiari malformation type I symptoms and diagnostic experiences: a report from the national Conquer Chiari Patient Registry database

Chiari malformation (CM) is a condition in which cerebellar tonsillar ectopia may manifest with various clinical presentations. This study reports from the only national, online patient registry available, the symptoms, comorbid neurocognitive and psychological conditions, and diagnostic experiences of patients living with CM type I (CM I). The current research is one component of a large investigation designed to collect information from individuals with CM through the online Conquer Chiari Patient Registry questionnaire. Analyses included descriptive statistics to study body system impact and patient diagnostic experiences. Participants were 768 individuals with CM I and were predominantly female (86.8 %) and Caucasian (93.8 %) with an average age of 35 years. Pain was the most frequently reported symptom (76.69 %) experienced prior to diagnosis with headaches implicated most often (73.44 %). Neurocognitive comorbidities included memory difficulties (43.88 %) and aphasia (43.75 %) and psychological disorders such as depression (31.77 %) and anxiety disorders (19.92 %) were reported. Average time to diagnosis from first physician visit to diagnosis was 3.43 years, and only 8.46 % of patients had previous awareness of CM. CM I diagnosis was found incidentally for 24.87 % of participants. Common misdiagnoses were classified as psychological (19.26 %) and neurological (19.26 %). Fear was the most frequent emotion elicited at the time of correct diagnosis (42.19 %). CM I can be a challenging condition for patients and physicians, during both the search for diagnosis and management of symptoms. Patient and physician education about CM I may permit early intervention and the prevention of further deterioration and patient suffering.

Medullary position at the craniocervical junction in mature cavalier King Charles spaniels: relationship with neurologic signs and syringomyelia

Background

Medullary elevation (ie, medullary kinking) at the craniocervical junction (CCJ) is reported in dogs with Chiari‐like malformations (CM), but its diagnostic criteria and clinical relevance are unclear.

Objective

To describe the position of the medulla at the CCJ in mature cavalier King Charles spaniels (CKCS), and evaluate its relationship with clinical status and the presence of syringomyelia.

Animals

Thirty‐six CKCS, 5–12 years of age, including 16 asymptomatic dogs.

Methods

Dogs were assigned a neurologic grade; magnetic resonance imaging (MRI) of the CCJ then was performed. The presence of a CM and syringomyelia was recorded and syringomyelia severity was quantified. Medullary position was quantified using the medullary kinking index, the elevation angle and obex position relative to the foramen magnum. The relationship between medullary position measures and presence and severity of neurologic signs and syringomyelia was investigated.

Results

Chiari‐like malformation was found in 33 dogs; 26 of them had syringomyelia. Mean medullary kinking index was 46.4% (SD, 10.3), elevation angle was 132° (SD, 12) and obex position was 3.5 mm (SD, 0.8). A higher medullary kinking index was associated with the presence of neurologic signs (P = .0368). Obex position was associated with the presence (P = .0018) and severity of syringomyelia (P = .0164).

Conclusions and clinical importance

There is a significant association between medullary elevation and clinical signs, whereas more caudal brainstem positions appear related to the presence of syringomyelia.

Diffusion tensor imaging in cervical syringomyelia secondary to Chiari I malformation: preliminary results

STUDY DESIGN

A prospective observational analysis.

OBJECTIVE

The aim was to perform a quantitative analysis of the neuronal status in cervical syringomyelia secondary to Chiari I malformation (CMI-S) using diffusion tensor imaging.

SUMMARY OF BACKGROUND DATA

Syringomyelia is a common finding in patients with CMI. Conventional imaging techniques frequently fail to assist clinicians in quantitatively assessing the neural damage in these patients.

METHODS

Twenty-three patients with CMI-S (aged 8-25 yr) were prospectively enrolled from April 2012 to August 2013. Sensitivity encoding single-shot echo-planar imaging was used for the sagittal diffusion tensor imaging. Fractional anisotropy (FA) values in the spinal cord were compared between the patients and normal volunteers and further evaluated with respect to syrinx severity and neurological signs/symptoms.

RESULTS

Compared with the normal controls, the FA values were significantly decreased at the level of the syrinx (0.429 ± 0.015 vs. 0.533 ± 0.007; P < 0.001), whereas no significant decreased FA value was measured in the tissue rostral and caudal to the syrinx. Concerning patients with different size of the syrinx, significantly decreased FA values at the syrinx level were observed in patients with a distended syrinx in comparison with those with a nondistended syrinx (0.397 ± 0.013 vs. 0.480 ± 0.018; P < 0.001). Moreover, the FA value at the syrinx level was found to be significantly decreased in the symptomatic group when compared with the nonsymptomatic or control groups (P < 0.05), and there was also a significant difference between the 2 latter groups (P < 0.05).

CONCLUSION

Decreased FA value at the syrinx levels may provide evidence of increased microstructural damage within the spinal cord parenchyma at this area, and changes in this diffusion tensor imaging parameter are significantly related to syrinx size and to the appearance of neurological signs/symptoms.

LEVEL OF EVIDENCE

4.

Are Established Methods of Physiotherapeutic Management for Long-term Neurological Conditions Applicable to 'Orphan' Conditions such as Syringomyelia?

BACKGROUND AND PURPOSE

Syringomyelia is a rare or 'orphan' condition with the potential to cause significant disability and detrimental effects to quality of life. Syringomyelia shares similar symptoms to those common in other long-term neurological conditions, including spinal cord injury and multiple sclerosis. In these more prevalent conditions, physiotherapy is utilized widely and is effective in optimizing physical, psychological and social parameters. Therefore, we theorized that physiotherapy might be transferable to, and beneficial to syringomyelia patients. As a paucity of literature exists in this area, we aimed to evaluate the existing uptake and perceived efficacy of physiotherapy.

METHODS

An exploratory, mixed methodology was selected to derive sufficient qualitative data for analysis. Specifically designed questionnaires and semi-structured interviews yielded data on uptake and perceived physiotherapy efficacy. One hundred patients from a National Health Service tertiary syringomyelia service were invited to participate.

RESULTS

The questionnaire and interviews were completed by 49 and 20 patients, respectively. Of the small number of patients receiving physiotherapy, the majority reported beneficial effects on pain modulation and quality of life. Stretching and hydrotherapy were deemed effective for relief of pain and stiffness. Additionally, physiotherapy was reported to provide similar benefits to surgical intervention.

DISCUSSION

Syringomyelia patients report physiotherapy to provide benefits for symptom management and quality of life. Such findings suggest that established rehabilitation techniques in more common conditions may be transferable to those less prevalent. Uptake of physiotherapy was limited, seemingly because of inadequate information, knowledge and resources. To address these deficiencies, further studies should be planned investigating the effectiveness of physiotherapy modalities, such as hydrotherapy, in parallel or in conjunction with surgery and/or pharmacology. Additionally, syringomyelia could be represented alongside similar pathologies in research trials to initiate further research questions and drivers for funding.

Shunt malfunction presenting with symptomatic syringomyelia: Demonstrated on contrast ventriculogram

Ventriculoperitoneal (VP) shunt malfunction commonly presents as raised intracranial pressure. Rarely, when the central canal of the spinal cord communicates with the 4^th ventricle, shunt malfunction can present as an expanding syrinx. The diagnosis is often delayed, resulting in severe morbidity. Some of these patients undergo repeated syrinx surgeries without much benefits. We report a case of chronic tuberculous meningitis with shunt malfunction presenting as an expanding spinal canal syrinx and quadriparesis. Fourth ventricular communication with syrinx was demonstrated with the help of a contrast ventriculogram. After shunt revision, syrinx resolved completely and the patient made significant improvement in his neurological deficits. The present case illustrates that a historical and rarely used investigation like contrast ventriculogram aids in the diagnosis and management even in the current neurosurgical practice. All patients with late onset syrinx and a previous VP shunt need to be investigated for shunt malfunction before considering syrinx surgery. A simple shunt revision resolves the syrinx in such conditions and avoids more complex procedures like Foramen magnum decompression. Relevant literature has been reviewed; pathophysiology and management options have been discussed.

Chiropractic care for headaches and dizziness of a 34-year-old woman previously diagnosed with Arnold-Chiari malformation type 1

OBJECTIVE

The purpose of this case study is to describe the chiropractic care of a patient with headaches and dizziness.

CLINICAL FEATURES

A 34-year-old woman with a history of headaches, dizziness, photophobia, and temporary loss of vision aggravated by postural positions while bending forward sought conservative care for her symptoms. She reported a prior diagnosis of Arnold-Chiari malformation (ACM) type 1 by magnetic resonance imaging in 2005 that revealed descending cerebellar tonsils measured at 5 mm with an impression of ACM type 1. A new magnetic resonance image taken in 2013 indicated the cerebellar tonsils measured at 3 mm and did not project through the plane of the foramen magnum. The diagnosis of ACM type 1 was no longer applicable; however, the signs and symptoms of ACM type 1 persisted.

INTERVENTION AND OUTCOME

She was treated using cervical chiropractic manipulation using diversified technique. The dizziness and headache were resolved after 3 visits. At her 3-month follow-up, she continued to be symptom-free.

CONCLUSION

A patient with headaches and dizziness and a previous diagnosis of ACM type 1 responded positively to chiropractic care.

Audio-vestibular signs and symptoms in Chiari malformation type i. Case series and literature review

INTRODUCTION

Chiari malformation is an alteration of the base of the skull with herniation through the foramen magnum of the brain stem and cerebellum. Although the most common presentation is occipital headache, the association of audio-vestibular symptoms is not rare. The aim of our study was to describe audio-vestibular signs and symptoms in Chiari malformation type i (CM-I).

MATERIALS AND METHODS

We performed a retrospective observational study of patients referred to our unit during the last 5 years. We also carried out a literature review of audio-vestibular signs and symptoms in this disease.

RESULTS

There were 9 patients (2 males and 7 females), with an average age of 42.8 years. Five patients presented a Ménière-like syndrome; 2 cases, a recurrent vertigo with peripheral features; one patient showed a sudden hearing loss; and one case suffered a sensorineural hearing loss with early childhood onset. The most common audio-vestibular symptom indicated in the literature in patients with CM-I is unsteadiness (49%), followed by dizziness (18%), nystagmus (15%) and hearing loss (15%). Nystagmus is frequently horizontal (74%) or down-beating (18%). Other audio-vestibular signs and symptoms are tinnitus (11%), aural fullness (10%) and hyperacusis (1%). Occipital headache that increases with Valsalva manoeuvres and hand paresthesias are very suggestive symptoms.

CONCLUSIONS

The appearance of audio-vestibular manifestations in CM-I makes it common to refer these patients to neurotologists. Unsteadiness, vertiginous syndromes and sensorineural hearing loss are frequent. Nystagmus, especially horizontal and down-beating, is not rare. It is important for neurotologists to familiarise themselves with CM-I symptoms to be able to consider it in differential diagnosis.

Chiari-like malformation and syringomyelia in American Brussels Griffon dogs

Background

Although Chiari‐like malformation (CM) and syringomyelia (SM) have been described in many small breed dogs, the prevalence and clinical manifestations of this complex have not been documented in a large cohort of American Brussels Griffon (ABG) dogs.

Objectives

To characterize the clinical and magnetic resonance imaging (MRI) features of CM and SM in the ABG breed.

Animals

Eighty‐four American Kennel Club registered ABG dogs were recruited.

Methods

Prospective study. Complete histories and neurologic examinations were obtained before MRI. Images were blindly reviewed and calculations were made by using OsiriX. All analyses were performed by Student's t‐test, Spearman's correlation, ANOVA, and chi‐square test where appropriate.

Results

Chiari‐like malformation and SM were present in 65% and 52% of dogs, respectively. Twenty‐eight percent of dogs had neurologic deficits and 20% had neck pain. Mean central canal (CC) transverse height was 2.5 mm with a mean length of 3.6 cervical vertebrae. Neurologic deficits were significantly associated with a larger syrinx (P = .04, P = .08) and syrinx size increased with age (P = .027). SM was associated with a smaller craniocervical junction (CCJ) height (P = .04) and larger ventricles (P = .0001; P < .001).

Conclusions and Clinical Importance

Syringomyelia and CM are prevalent in American Brussels Griffon dogs. Syrinx size is associated with neurologic deficits, CM, larger ventricles, a smaller craniocervical junction height, neurologic deficits, and cerebellar herniation. Fifty‐two percent of dogs with a SM were clinically normal.

Occipital and craniocervical pain and brain MRI in children with migraine

BACKGROUND

Both cervical and occipital pain has been reported in pediatric patients with migraine. There are no descriptions of anatomical changes on conventional brain magnetic resonance imaging that can explain the pathophysiology of headache with cervical and occipital pain in this age group. Our aim was to evaluate the frequency of cervical and occipital pain in children and adolescents with migraine as opposed to other types of headache and to seek corresponding anatomic abnormalities on brain magnetic resonance imaging.

METHODS

The cohort included 194 patients with headache attending the ambulatory headache clinic of a pediatric tertiary medical center. Data were collected by medical file review and revision of conventional magnetic resonance scans.

RESULTS

Patients were divided into two groups: migraine headache (n = 125) and other types of headache (n = 69). Occipital pain was reported by 16.4% of the patients and cervical pain by 4.1%; neither type of pain was characteristic of migraine headache in particular. Brain magnetic resonance imaging did not show any anatomic changes specific to migraine or other headache types, regardless of the presence of occipital or cervical pain.

CONCLUSIONS

Occipital and cervical pain are not characteristic symptoms of any headache group in the pediatric age group, and their presence or absence does not correspond to changes on conventional brain magnetic resonance imaging.

Dural sinus filling defect: intrasigmoid encephalocele

Filling defects of dural venous sinuses are considered to be a challenging problem especially in case of symptomatic patients. Many lesions have to be ruled out such as sinus thrombosis, arachnoid granulations and tumours. Encephalocele into dural sinus is also a rare cause of these filling defects of dural sinuses. Here, we report an extremely rare case with spontaneous occult invagination of temporal brain tissue into the left sigmoid sinus and accompanying cerebellar ectopia.

Influence of congenital central nervous system malformations on postoperative complications following placement of cerebrospinal fluid shunts in pediatric and adolescent patients

BACKGROUND

This retrospective study was designed to evaluate whether patients with hydrocephalus associated with central nervous system (CNS) anomalies, compared with patients with hydrocephalus and absent CNS anomalies, present with significantly higher rate of postoperative complications, including more serious clinical presentation, increased life threat, and higher postoperative or late mortality rate.

METHODS

We performed a retrospective study using medical records of 100 patients of pediatric and adolescent age (0-18 years) between 2004 and 2010 treated with operative cerebrospinal fluid (CSF) shunt placement.

RESULTS

In both groups of patients, there were 43 postoperative complications, including 12 mechanical obstructions of the CSF drainage systems, 13 disconnections, 11 dislocations of proximal catheter, 6 inflammatory complications (meningitis), and 1 latex allergy. Patients with hydrocephalus associated with CNS anomalies were presented with statistically higher rate of postoperative complications (U = 303.5, z = -3.27, p = 0.001), higher number of operations, at least one complication more per patient, more complicated clinical course, higher life threat, and higher late mortality rate.

CONCLUSIONS

After installing the CSF drain system, children and adolescents with hydrocephalus associated with anomalies of the CNS require regular and careful follow-up.

Type I Chiari malformation presenting central sleep apnea

Sleep apnea is a rare but a well-known clinical feature of type I Chiari malformation. It may be obstructive or central in nature. Sleep apnea in patients with type I Chiari malformation rarely presents without accompanying neurological signs or symptoms. We here report a case of a 10-year-old girl who presented with central sleep apnea without any other neurological signs but was ultimately diagnosed with type I Chiari malformation. The patient initially showed mild improvement in symptoms after administration of an acetazolamide. Finally, posterior fossa decompression dramatically improved her respiratory status during sleep, both clinically and on polysomnography. This case suggests that type I Chiari malformation should be considered in the differential diagnoses of central apneas in children, even if there are no other neurological signs and symptoms. Furthermore, sagittal craniocervical magnetic resonance imaging may be necessary for a definitive diagnosis.

An update on the pathogenesis of syringomyelia secondary to Chiari-like malformations in dogs

Syringomyelia (SM) is a spinal cord disease that can cause neuropathic pain in dogs. The pathogenesis of SM secondary to Chiari-like malformation (CM) has been the focus of intense research in recent years. The gulf in our understanding of CM/SM in dogs relative to the analogous human condition has progressively narrowed. CM is primarily a disease of abnormal geometric morphometry affecting the caudal cranial fossa and the brain parenchyma contained within it. This review describes how advanced imaging techniques have revealed a series of morphometric abnormalities associated with CM/SM. The series is presented in a logical order to help describe the pathogenesis of CM and the subsequent formation of syringes, with particular reference to the concepts of craniospinal compliance and cerebrospinal fluid pulse pressure timing.

Chiari 1 malformation and holocord syringomyelia in hunter syndrome

Compressive cervical myelopathy is a well-known life-threatening complication in mucopolysaccharidosis (MPS) patients. Glycosaminoglycan accumulation in the growing cartilage results in dens dysplasia, atlanto-axial instability, and subsequent periodontoid fibrocartilaginous tissue deposition with upper cervical stenosis.Chiari malformation type 1 (CM1) is a congenital downward cerebellar tonsil ectopia determined by clivus and posterior cranial fossa underdevelopment, possibly leading to progressive spinal cord cavitation (syringomyelia) and severe neurological impairment.We present a boy affected with Hunter syndrome (MPS II) and cerebellar tonsil ectopia who developed a holocord syringomyelia at the age of 6 years. The child underwent atlanto-occipital decompressive surgery with rapid clinical and neuroimaging improvement.Sharing a primary mesenchymal involvement of the cervical-occipital region, the coexistence of CM1 in MPS might be not unexpected and complicate further the disease course. In these patients, strict monitoring and prompt treatment might be of foremost importance for preventing major neurological complications.

Sleep disordered breathing in children and adolescents with Chiari malformation type I

STUDY OBJECTIVES

Chiari malformation Type I (CM-I) has been associated with sleep disordered breathing (SDB). The aim of this study was to evaluate the prevalence of SDB in CM-I and its clinical correlates in a population of children and adolescents.

METHODS

Fifty-three consecutive children and adolescents affected by CM-I were enrolled (27 girls and 26 boys, mean age 10.3 ± 4.3, range: 3-18 years). All patients underwent neurological examination, MRI, and polysomnography (PSG). Otorhinolaryngologic clinical evaluation was performed in patients with polysomnographic evidence of sleep-related upper airway obstruction.

RESULTS

Mean size of the herniation was 9.5 ± 5.4 mm. Fourteen patients had syringomyelia, 5 had hydrocephalus, 31 presented neurological signs, 14 had epileptic seizures, and 7 reported poor sleep. PSG revealed SDB in 13 subjects. Patients with SDB, compared to those without SDB, had a higher prevalence hydrocephalus (p = 0.002), syringomyelia (p = 0.001), and neurological symptoms (p = 0.028). No significant difference was observed in age, gender, prevalence of epilepsy, and size of the herniation. Obstructive SDB was associated with syringomyelia (p = 0.004), whereas central SDB was associated with hydrocephalus (p = 0.034).

CONCLUSIONS

In our population of CM-I patients the prevalence of SDB was 24%, lower than that reported in literature. Moreover, our findings suggest that abnormalities in cerebrospinal fluid dynamics in CM-I, particularly syringomyelia and hydro-cephalus, are associated with SDB.

Arnold-Chiari 1 malformation type 1 with syringohydromyelia presenting as acute tetraparesis: a case report

CONTEXT

A 19-year-old woman who presented to a community hospital after awakening with tetraparesis, generalized paresthesia, and severe neck pain, and was transferred to an acute care hospital.

FINDINGS

Magnetic resonance imaging of the head and spine was performed and revealed a cystic lesion extending from the C1 level to the C6 level as well as an Arnold-Chiari type 1 malformation. Emergent surgical posterior fossa decompression with duraplasty and C1 laminectomy was undertaken. Most symptoms improved immediately postoperatively. On post-operative day 15, the patient was transferred to our acute rehabilitation hospital for an additional 16 days. With continued aggressive therapy, she demonstrated complete resolution of tetraparesis as well as significant improvement in muscle strength and function in addition to resolution of paresthesia and neck pain. Functional independence measure scores were 69/126 on admission to 110/126 on discharge from the rehabilitation hospital. Her tetraparesis eventually resolved; manual muscle testing scores on follow-up 2 months later were 5/5 in all four extremities.

CLINICAL RELEVANCE

This is the first reported case of Chiari I malformation with syringohydromyelia presenting as acute tetraparesis, generalized paresthesia, and neck pain. Surgical decompression leading to resolution of symptoms made other etiologies extremely unlikely and there was no history of trauma. The different theories on the pathogenesis of syringomyelia are discussed.

The need in dural graft suturing in Chiari I malformation decompression: A prospective, single-blind, randomized trial comparing sutured and sutureless duraplasty materials

BACKGROUND

This study compared the use of two commonly utilized dural closure techniques used in augmentation duraplasty for Chiari malformation I (CM I) and evaluated their efficacy and outcome in terms of quality of life assessments.

METHODS

This prospective randomized study compared sutureless (DuraGen) and suturable (Dura-Guard) techniques in CM I decompression. Clinical parameters, cost analysis, and SF-36 Quality of Life Questionnaire (QLQ) were utilized to assess outcome.

RESULTS

Thirty-four patients were enrolled. Average age was 38.7 ± 12.2 years (mean ± SD (Standard Deviation)) and 82% of patients were female. Sixteen patients received DuraGen and 18 Dura-Guard. Age and gender were similar among groups. Postoperative complications did not differ between groups. Operative cost and time were less for DuraGen, whereas hospital stay was less with Dura-Guard, neither was statistically significant. Average QLQ scores at months 1, 2, and 3 improved in both groups. Dura-Guard patients showed greater improvement in quality of life at month 2 (P < 0.05) but groups did not differ at final survey. All patient's physical health (P < 0.005) and function (P < 0.005) were significantly improved. Outcome did not differ between groups and all patients showed significant improvement (P < 0.05).

CONCLUSION

Both techniques are effective in reaching the goals of decompressive surgery for CM I and did not differ in quality of life at final survey. All patients showed significant improvement in physical function, physical health, and outcome following surgery. With all variables being equal the choice of duraplasty material may be based upon surgeon's preference.

Novel cAMP binding protein-BP (CREBBP) mutation in a girl with Rubinstein-Taybi syndrome, GH deficiency, Arnold Chiari malformation and pituitary hypoplasia

Background

Rubinstein-Taybi syndrome (RTS) is a rare autosomal dominant disorder (prevalence 1:125,000) characterised by broad thumbs and halluces, facial dysmorphism, psychomotor development delay, skeletal defects, abnormalities in the posterior fossa and short stature. The known genetic causes are point mutations or deletions of the cAMP-response element binding protein-BP (CREBBP) (50-60% of the cases) and of the homologous gene E1A-binding protein (EP300) (5%).

Case presentation

We describe, for the first time in literature, a RTS Caucasian girl, 14-year-old, with growth hormone (GH) deficiency, pituitary hypoplasia, Arnold Chiari malformation type 1, double syringomyelic cavity and a novel CREBBP mutation (c.3546insCC).

Conclusion

We hypothesize that CREBBP mutation we have identified in this patient could be responsible also for RTS atypical features as GH deficiency and pituitary hypoplasia.

Long-term results after posterior fossa decompression in syringomyelia with adult Chiari Type I malformation

Object

There is little information about the long-term effectiveness and complications following decompressive surgery for syringomyelia related to Chiari malformation Type I (CM-I).

Methods

Examining long-term clinical and radiological follow-up, the authors studied a mixed retrospective and prospective single-institution cohort of 109 consecutive surgically treated adult patients with syringomyelia and CM-I. All patients underwent a standardized surgical protocol: decompression of the craniocervical junction, arachnoid exploration, and shrinkage of the cerebellar tonsils. Factors predicting outcome were investigated.

Results

The retrospective arm consisted of 41 cases treated between 1990 and 1994, and the prospective arm comprised 68 patients treated between 1994 and 2001. The mean overall age was 45.9 years, and 58.8% of the population was female. The median follow-up period was 12.7 years. The most frequent initial symptoms were pain and sensory and gait disturbances. There was no perioperative death or neurological deterioration. The comprehensive perioperative complication rate was approximately 11%, with 3 cases (2.7%) of CSF leakage. Regression analysis showed that the best combination of clinical and radiological outcome predictors was age and duration of symptoms. Clinical follow-up confirmed surgical result stability with clinical improvement of greater than 90% of the spinal and cranial manifestations over a long-term period. Two patients had radiological recurrences of syringomyelia without clinical signs 85 and 124 months after surgery.

Conclusions

Certain clinical predictors of poor clinical and radiological prognosis were identified—namely, age at time of surgery and symptom duration. The results of the study provide additional long-term data that support the effectiveness and safety of relieving CSF block at the craniocervical junction in CM-I–related syringomyelia.

Volume reduction of the jugular foramina in Cavalier King Charles Spaniels with syringomyelia

Background

Understanding the pathogenesis of the chiari-like malformation in the Cavalier King Charles Spaniel (CKCS) is incomplete, and current hypotheses do not fully explain the development of syringomyelia (SM) in the spinal cords of affected dogs. This study investigates an unconventional pathogenetic theory for the development of cerebrospinal fluid (CSF) pressure waves in the subarachnoid space in CKCS with SM, by analogy with human diseases. In children with achondroplasia the shortening of the skull base can lead to a narrowing of the jugular foramina (JF) between the cranial base synchondroses. This in turn has been reported to cause a congestion of the major venous outflow tracts of the skull and consequently to an increase in the intracranial pressure (ICP). Amongst brachycephalic dog breeds the CKCS has been identified as having an extremely short and wide braincase. A stenosis of the JF and a consequential vascular compromise in this opening could contribute to venous hypertension, raising ICP and causing CSF jets in the spinal subarachnoid space of the CKCS. In this study, JF volumes in CKCSs with and without SM were compared to assess a possible role of this pathologic mechanism in the development of SM in this breed.

Results

Computed tomography (CT) scans of 40 CKCSs > 4 years of age were used to create three-dimensional (3D) models of the skull and the JF. Weight matched groups (7–10 kg) of 20 CKCSs with SM and 20 CKCSs without SM were compared. CKCSs without SM presented significantly larger JF -volumes (median left JF: 0.0633 cm³; median right JF: 0.0703 cm³; p < 0.0001) when compared with CKCSs with SM (median left JF: 0.0382 cm³; median right JF: 0.0434 cm³; p < 0.0001). There was no significant difference between the left and right JF within each group. Bland-Altman analysis revealed excellent reproducibility of all volume measurements.

Conclusion

A stenosis of the JF and consecutive venous congestion may explain the aetiology of CSF pressure waves in the subarachnoid space, independent of cerebellar herniation, as an additional pathogenetic factor for the development of SM in this breed.

International spinal cord injury musculoskeletal basic data set

OBJECTIVES

To develop an International Spinal Cord Injury (SCI) Musculoskeletal Basic Data Set as part of the International SCI Data Sets to facilitate consistent collection and reporting of basic musculoskeletal findings in the SCI population.

SETTING

International.

METHODS

A first draft of an SCI Musculoskeletal Basic Data Set was developed by an international working group. This was reviewed by many different organizations, societies and individuals over 9 months. Revised versions were created successively.

RESULTS

The final version of the International SCI Musculoskeletal Basic Data Set contains questions on neuro-musculoskeletal history before spinal cord lesion; presence of spasticity/spasms; treatment for spasticity within the last 4 weeks; fracture(s) since the spinal cord lesion; heterotopic ossification; contracture; the location of degenerative neuromuscular and skeletal changes due to overuse after SCI; SCI-related neuromuscular scoliosis; the method(s) used to determine the presence of neuromuscular scoliosis; surgical treatment of the scoliosis; other musculoskeletal problems; if any of the musculoskeletal challenges above interfere with activities of daily living. Instructions for data collection and the data collection form are freely available on the International Spinal Cord Society (ISCoS) website (www.iscos.org.uk).

CONCLUSION

The International SCI Musculoskeletal Basic Data Set will facilitate consistent collection and reporting of basic musculoskeletal findings in the SCI population.

Surgical management of patients with Chiari I malformation

Chiari malformations (CMs) constitute a variety of four mainly syndromes (I, II, III, and IV), which describe the protrusion of brain tissue into the spinal canal through the foramen magnum. These malformations frequently occur in combination with other pathological entities such as myelomeningocele, hydrocephalus, and/or hydrosyringomyelia. The recent improvement of imaging techniques has increased not only the rate of CM diagnosis but also the necessity for its early treatment. Several different surgical techniques have been employed in the treatment of patients with symptomatic CM-I. In our current study, a systematic and critical review of the pertinent literature was made for identifying the most commonly employed surgical procedures in the management of these patients. Emphasis was given in outlining the advantages and disadvantages of each surgical approach. Moreover, an attempt was made for defining those parameters that may be prognostic factors for their surgical outcome. There is a consensus that surgical treatment is reserved only for symptomatic patients with CM-I. It has also been postulated that early surgically intervention is usually associated with better outcome. Despite the large number of previously published clinical series, further clinical research with large-scale studies is necessary for defining surgical treatment guidelines in these patients.

Estimation of the brain stem volume by stereological method on magnetic resonance imaging

Neuron loss that occurs in some neurodegenerative diseases can lead to volume alterations by causing atrophy in the brain stem. The aim of this study was to determine the brain stem volume and the volume ratio of the brain stem to total brain volume related to gender and age using new Stereo Investigator system in normal subjects. For this purpose, MR images of 72 individuals who have no pathologic condition were evaluated. The total brain volumes of female and male were calculated as 966.81 ± 77.44 and 1,074.06 ± 111.75 cm3, respectively. Brain stem volumes of female and male were determined as 18.99 ± 2.36 and 22.05 ± 4.01 cm3, respectively. The ratios of brain stem volume to total brain volume were 1.96 ± 0.17 in female and 2.05 ± 0.29 in male. The total brain and brain stem volumes were observed smaller in female and it is statistically significant. Among the individuals whose ages are between 20 and 40, total brain and brain stem volume measurements with aging were not statistically significant. As a result, we believe that the measurement of brain stem volume with an objective and efficient calculation method will contribute to the early diagnosis of neurodegenerative diseases, as well as to determine the rate of disease progression, and the outcomes of treatment.

2011 SOSORT guidelines: Orthopaedic and Rehabilitation treatment of idiopathic scoliosis during growth

BACKGROUND

The International Scientific Society on Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT), that produced its first Guidelines in 2005, felt the need to revise them and increase their scientific quality. The aim is to offer to all professionals and their patients an evidence-based updated review of the actual evidence on conservative treatment of idiopathic scoliosis (CTIS).

METHODS

All types of professionals (specialty physicians, and allied health professionals) engaged in CTIS have been involved together with a methodologist and a patient representative. A review of all the relevant literature and of the existing Guidelines have been performed. Documents, recommendations, and practical approach flow charts have been developed according to a Delphi procedure. A methodological and practical review has been made, and a final Consensus Session was held during the 2011 Barcelona SOSORT Meeting.

RESULTS

The contents of the document are: methodology; generalities on idiopathic scoliosis; approach to CTIS in different patients, with practical flow-charts; literature review and recommendations on assessment, bracing, physiotherapy, Physiotherapeutic Specific Exercises (PSE) and other CTIS. Sixty-five recommendations have been given, divided in the following topics: Bracing (20 recommendations), PSE to prevent scoliosis progression during growth (8), PSE during brace treatment and surgical therapy (5), Other conservative treatments (3), Respiratory function and exercises (3), Sports activities (6), Assessment (20). No recommendations reached a Strength of Evidence level I; 2 were level II; 7 level III; and 20 level IV; through the Consensus procedure 26 reached level V and 10 level VI. The Strength of Recommendations was Grade A for 13, B for 49 and C for 3; none had grade D.

CONCLUSION

These Guidelines have been a big effort of SOSORT to paint the actual situation of CTIS, starting from the evidence, and filling all the gray areas using a scientific method. According to results, it is possible to understand the lack of research in general on CTIS. SOSORT invites researchers to join, and clinicians to develop good research strategies to allow in the future to support or refute these recommendations according to new and stronger evidence.

The efficacy of intravenous patient-controlled analgesia after intracranial surgery of the posterior fossa: a prospective, randomized controlled trial

BACKGROUND

Surgery of the posterior fossa often produces intense postoperative pain. However, this pain is infrequently treated because of concern that opioid administration may mask the postoperative neurologic examination and/or produce hypercarbia. In this prospective, randomized controlled trial, we sought to determine whether IV patient-controlled analgesia (PCA) would lead to reductions in postoperative pain after neurosurgical procedures of the posterior fossa compared with conventional IV nurse-administered as-needed (PRN) therapy.

METHODS

Eighty patients (age range, 18-82 years) undergoing elective posterior fossa surgery were randomized to receive postoperative IV fentanyl PRN 25 to 50 μg every 30 minutes or via PCA 0.5 μg/kg/dose, with a maximal dose limit of 50 μg, and 15-minute lockout (4 doses/hour). We measured pain (Numerical Rating Scale, 0-10), analgesic use, sedation (Ramsay Sedation Scale and Glasgow Coma Scale), respiration, hemodynamics, and adverse events hourly.

RESULTS

Sixty-five patients completed the study. Thirty-one patients received IV PCA and 34 received PRN analgesia. Patient demographics did not differ between groups. Patients in the PCA group reported less pain at rest (mean [95% confidence interval]: 3.7 [3.0, 4.4] vs 5.2 [4.5, 5.8], P = 0.003) and received more fentanyl (mean [95% confidence interval]: 54.8 [42.1, 67.6] vs 29.9 [24.2, 35.7] μg/h, P = 0.002) than those in the PRN group. There were no differences in side effects and no adverse events related to analgesic therapy.

CONCLUSIONS

IV PCA use resulted in reduction in postoperative pain compared with PRN analgesic therapy after surgery of the posterior fossa. Larger studies will be required to determine the safety of IV PCA in this patient population.

Nocturnal apnea in Chiari type I malformation

A 4-year-old girl presented with sleep-disordered breathing. Her parents described breathing pauses of up to 20 s and progressive tiredness during the day. Obstructive apneas from an enlarged adenoid were thought to be the most probable cause. However, an adenotomy did not resolve the problem. Polysomnography demonstrated central apneas, and cerebral magnetic resonance imaging revealed a Chiari type I malformation. We describe the differential diagnosis of apnea in children and the role of polysomnography in the distinction between obstructive and central apneas.

CONCLUSION

This case illustrates that, in children with apnea, it is important to consider central causes as well as the more common obstructive causes, even in the absence of additional neurological signs or symptoms.

Identical twin sisters with Rubinstein-Taybi syndrome associated with Chiari malformations and syrinx

Chiari malformations are multifactorial and heterogeneous entities, characterized by abnormalities in the posterior fossa. They have been identified in association with various genetic syndromes in recent years. Two previous studies have noted an association of Chiari malformations with Rubinstein-Taybi syndrome (RTS). In this clinical report, we highlight identical twins with RTS caused by a mutation in CREBBP that presented with slightly different Chiari malformations in association with an extensive multiloculated syrinx and scoliosis. RTS has been found to be associated with craniocervical abnormalities in literature review, and this clinical report demonstrates the prudent consideration of the physician who cares for patients impacted by RTS to effectively screen via symptomatology and physical examination for Chiari pathology or other craniocervical abnormalities.

Posterior cranial fossa morphometry in symptomatic adult Chiari I malformation patients: comparative clinical and anatomical study

BACKGROUND AND OBJECTIVES

The cerebellar tonsillar herniation occurring in Chiari malformation Type I (CMI) mainly results from overcrowding of a normally developing hindbrain within a primary small posterior cranial fossa (PCF) due to an anomaly in the embryological development of the occipital bone. In the present study, the lengths of PCF parameters were studied in adult CMI patients.

PATIENTS AND METHODS

The authors retrospectively examined 15 adult patients with CMI. Multiple measurements were made on magnetic resonance images (MRIs). The results were compared with the findings in 25 controls and 30 dry skulls.

RESULTS

Length of the neural structures did not significantly differ between the CMI and the control groups. The average length of the basiocciput was significantly shorter in the CMI group as compared with the control group. The mean length of the supraocciput was significantly shorter and the average diameter of the foramen magnum was significantly longer in the CMI group when compared to the control group and dry skulls.

CONCLUSIONS

The morphometric data suggest that, in CMI, a hypoplastic occipital bone, possibly due to the paraxial mesodermal defect of the parachordal plate, causes overcrowding in PCF, which contains the normally developed neural structures.

Chiari 1 malformation and holocord syringomyelia presenting as abrupt onset foot drop

We present two patients with a Chiari 1 malformation and holocord syringomyelia who presented with abrupt onset unilateral foot drop. Neurophysiologic testing was consistent with a proximal nerve root lesion. This assisted with localization and directed magnetic resonance (MR) imaging to lumbosacral spine and nerve roots. Each child underwent a suboccipital craniectomy and laminectomy with duroplasty to decompress the foramen magnum. Each child also showed rapid and complete clinical recovery despite the significant electromyographic and MRI abnormalities on initial study.

Chiari type I malformations in young adults: implications for the college health practitioner

The authors describe 2 cases of Chiari type I malformation (CM-I) in students presenting to a college health center within a 6-month period. A review of CM-I, including epidemiology, typical presentation, evaluation, and management, is followed by a discussion of the clinical and functional implications of the disorder in an emerging adult population.