Chiari type I malformation in children

We reviewed the recent experience at Texas Children's Hospital by examining the records of 11 children who underwent suboccipital decompression for symptomatic Chiari type I malformation. Presenting complaints included neck pain (1 child), scoliosis (4 children), back pain (1 child), torticollis (1), motor dysfunction (1), and apnea (3 children). Neurologic findings were normal in 7 of the 11 children. The craniocervical junction and medulla were studied by magnetic resonance imaging, which revealed anatomy consistent with Chiari type I malformation in all cases. At surgery, all patients had tonsillar herniation to the first cervical vertebra or below. Three patients had syringomyelia. Postoperatively, either the patients were symptom free or, in the cases of scoliosis and torticollis, there was no progression. Our experience suggests that Chiari type I malformation may occur in childhood with varied and unusual clinical findings. Magnetic resonance imaging was essential to the diagnosis; the presence of tonsillar herniation was confirmed at surgery. The results of suboccipital decompression were favorable in this series.     

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.     

Osteopetrosis with Chiari I malformation: presentation and surgical management

Osteopetrosis is a heterogeneous group of rare, inherited disorders of the skeleton that results in neurological manifestations due to restriction of growth of cranial foramina and calvarial thickening. A 25-year-old woman with a history of autosomal dominant osteopetrosis presented to the authors' institution with headache worsened by exertion and radiating from the occipital region forward with episodes of choking/coughing when eating and a loss of gag reflex on physical examination. On MR imaging, she was found to have severe posterior fossa calvarial thickening resulting in a small posterior fossa and tonsillar ectopia of 9 mm and compression and deformation of the brainstem. She underwent posterior fossa craniectomy, foramen magnum decompression, and partial C-1 laminectomy with external durotomy. The patient did well postoperatively with resolution of symptoms. This case describes a new neurological manifestation of autosomal dominant osteopetrosis. To the authors' knowledge, this report represents the first described case of extreme posterior fossa calvarial thickening from autosomal dominant osteopetrosis with associated Chiari I malformation (CM-I) requiring posterior fossa decompression and extradural decompression. Given previously published MR imaging data that demonstrate the association of osteopetrosis and CM may be more common than in this case alone, the authors discuss the need for further investigation of the incidence of CM-I in patients with autosomal dominant osteopetrosis. Additionally, they review osteopetrosis and other diagnoses of calvarial hyperostosis presenting as CM-I.     

The Chiari pseudotumor cerebri syndrome: symptom recurrence after decompressive surgery for Chiari malformation type I

INTRODUCTION: The etiology of Chiari malformation type I (CM1) as well as other anomalies associated with CM1 remains poorly defined. We have noted the presence of elevated CSF pressures with small ventricles, consistent with the pseudotumor cerebri (PTC) syndrome in a group of CM1 patients that did not respond over the long term to posterior fossa decompression. In order to better understand this association, we reviewed a series of CM1 patients treated by posterior fossa decompression to define the prevalence and nature of post-Chiari PTC. METHODS: We performed a retrospective chart review of 192 patients diagnosed with CM1 and treated by posterior fossa decompression. Patients who failed to respond to surgery were evaluated by CINE MR flow studies to assess presence of CSF flow at the foramen magnum and then by lumbar puncture if flow was present. The diagnosis of Chiari PTC was defined by recurrence of Chiari-like symptoms after decompression, elevated lumbar CSF pressure in the absence of ventriculomegaly, and transient resolution of symptoms with large volume lumbar CSF drainage. RESULTS: Thirty-six of 192 patients did not improve with surgical decompression. Fifteen of 36 operative CM1 patients (41.6%) were found to have Chiari PTC. The most frequent symptoms of CM1/PTC patients were head pain, body aches, and balance difficulties. Three patients also experienced visual complaints. The mean maximum lumbar CSF pressure documented in this cohort was 26 cm of water in adults and 25.3 in children. All patients received treatment for the CM1/PTC that culminated with CSF shunt placement in 14/15. Seven of 9 pediatric patients had significant symptom resolution while 6/6 adult patients remained variably symptomatic. CONCLUSION: CM1 and PTC co-exist in a surprising percentage of failed operative CM1 patients and present with a syndrome that is difficult to treat. The etiology of this association after Chiari decompression is unclear, though perhaps posterior fossa surgery in the setting of abnormal anatomy and potentially anomalous CSF flow dynamics contributes to CSF malabsorption and resultant or coexistant PTC.     

Chiari type I malformation causing central apnoeas in a 4-month-old boy

Apnoea is a rare but well-known clinical presentation of the Chiari type I malformation. It may be either obstructive or central in nature, and has been described in children, adolescents and adults. Here, we report a 4-month-old infant who presented with frequent central sleep apnoeas leading to the diagnosis of a Chiari type I malformation. Surgical repair resulted in complete resolution of the symptoms, normal respiratory parameters during sleep and normal psychomotor development.This case illustrates a very early presentation of the Chiari type I malformation with central apnoeas and suggests that this aetiology should be considered in the differential diagnosis of central apnoeas in infants, especially when they are associated with other neurological sign or symptom.     

Osteopetrosis with Arnold Chiari malformation type I and brain stem compression

Osteopetrosis is a collective term for a range of sclerosing bone diseases resulting from an absence or defective function of osteoclasts. The clinical expression is variable and includes skeletal, hematological and neurological manifestations. The common neurological manifestation includes cranial neuropathies involving optic, cochlear, facial and trigeminal nerves. Spastic quadriplegia occurring as a result of brain stem compression in osteopetrosis is uncommon. The association of Type 1 Arnold Chiari malformation with osteopetrosis resulting in brain stem compression syndrome is an extremely rare entity.     

Hemihypertrophy and the Chiari I malformation

We report two children with hemihypertrophy and Chiari I malformation (CIM) and review the extant medical literature regarding CIM and overgrowth disorders. We propose that these two entities do not represent a spurious association but rather share a common dysembryology of mesoderm.     

Seizures in paediatric Chiari type I malformation: the role of single-photon emission computed tomography

Chiari type I malformation is one of the posterior fossa maldevelopments with which different clinical manifestations have been associated. Seizures have only recently been associated with Chiari type I malformation. This study reports on 4 children with epilepsy (2M, 2F; age range 8-15 y) diagnosed with Chiari type I malformation by brain magnetic resonance imaging (MRI), in whom no cortical structural involvement was observed. In these patients an interictal ethylcysteinate-dimer-single-photon emission computed tomographic (ECD-SPECT) study was performed to define more precisely the relationship between Chiari type I malformation and seizures. In these patients the hypoperfusion area correlated with electroencephalographic (EEG) focal abnormalities. These hypoperfusions may represent the functional aspect of a cerebral microdysgenesis; seizures and EEG epileptic anomalies may also be linked to the complex network connection between cortices and cerebellar hemispheres. A cerebellar hypoperfusion was also detected in two of the four examined patients, indicating a functional or structural involvement. CONCLUSION: Interictal SPECT scans are helpful for the clarification of seizures in patients with Chiari type I malformation.     

Sleep apnea and vocal cord paralysis secondary to type I Chiari malformation

A previously healthy 13-year-old boy without myelodysplasia who had mild scoliosis was seen with complaints of nasal congestion, noisy nighttime breathing, and difficulty sleeping. Flattening of the inspiratory loop on the flow-volume curve was found on pulmonary function testing, suggesting a variable extrathoracic obstruction due to a laryngeal lesion. Bilateral abductor vocal cord paralysis and sleep apnea developed precipitously following general anesthesia. Further workup demonstrated a type-I Chiari malformation with syringomyelia. Brainstem abnormalities such as Chiari malformation with secondary tenth cranial nerve deficits should be considered in previously healthy children and adolescents with signs and symptoms of upper airway obstruction and apnea.     

The position of the conus medullaris in children with a Chiari I malformation

The purpose of this study is to determine whether there is a relationship between the conus level and patients with a Chiari I malformation. This retrospective MRI study evaluated conus levels and degrees of tonsillar ectopia in 26 children ages 5-16 years with a Chiari I malformation. Our results show that there seems to be no relationship between the conus level and the amount of tonsillar ectopia that a child with a Chiari I malformation might have. In fact, there seemed to be an inverse relationship between these two entities. Interestingly, we have also found that of all coni located at the L2-L3 disc space or below, these patients had a syrinx associated with their Chiari I malformation and that all malformations without a syrinx had a 'normally' positioned conus medullaris.     

Chiari I malformation: a review of 43 patients

We have reviewed the presentation, diagnosis, management, and outcome of 43 consecutive patients with the Chiari I malformation who were evaluated over a 12-year period and were managed by a single surgeon. The delay from the time of presentation to that of diagnosis was significantly less in the pediatric group when compared to the adult group. Also, the delay in diagnosis before 1985 was significantly longer than after 1985, the year magnetic resonance imaging became widely available in clinical practice. We were able to show the patients who did not have hydrosyringomyelia were unlikely to develop scoliosis. Surgery resulted in overall improvement in both symptoms and signs, but the improvement in symptoms was more marked than the improvement in signs. There was positive correlation between improvement in hydrosyringomyelia and the improvement in signs and symptoms. Surgery was associated with no significant permanent injury as a result of the procedure in any of the patients. The effect of Chiari surgery on scoliosis was inconclusive.     

Arnold Chiari type 1 malformation presenting with sleep disordered breathing in well children

Healthy children, aged 3, 9, and 13 years referred with sleep disordered breathing had marked central apnoea and bradypnoea on polysomnography, necessitating the use of non-invasive bilevel ventilation in two cases. Each had normal neurological examinations and an Arnold Chiari type 1 malformation was confirmed on magnetic resonance imaging. All underwent urgent posterior fossa decompression which normalised their sleep breathing.     

Asymmetry of tonsillar ectopia in Chiari I malformation

There has been almost no evaluation or discussion of the symmetry of tonsillar ectopia in the medical literature. We measured the degree of left and right tonsillar herniation in 42 pediatric patients with a symptomatic Chiari I malformation and made clinical/radiological correlations. 18% of all patients with tonsillar asymmetry had clinical symptoms or physical findings referable to the inequality of their hindbrain herniation. In addition, 95% of patients with a coexisting syringomyelia had a right cerebellar tonsillar herniation greater than the left. We hypothesize that slight differences in posterior cranial fossa morphology may physically allow for greater unilateral herniation of the left or right cerebellar tonsil, which may be manifested in a patient's clinical presentation.     

Two siblings with the Chiari I malformation

Two siblings with symptoms characteristic of the Chiari I malformation are described. The malformations were confirmed by magnetic resonance imaging scans and at surgery. Upon review of the world literature, no instance of the Chiari I malformation in a single family has been reported.     

Chiari I malformation in asymptomatic young children with Williams syndrome: clinical and MRI study.

We report clinical and magnetic resonance imaging findings in two young children, aged 2 years 4 months and 3 years, with Williams syndrome. Both showed a mild global delay, although their neurological examination was completely normal. Their magnetic resonance imaging, however, showed Chiari I malformation and some non-specific changes in the centrum semiovale and in the white matter posterior to the lateral ventricles. Cerebellar tonsils were displaced through the foramen magnum 8.5 and 7.5 mm respectively. Our results suggest that Chiari I malformation can also be a frequent feature in subjects with Williams syndrome even in the absence of overt neurological signs suggestive of it. Whether these children might develop acute signs later is not known at present. Further studies are needed not only to evaluate the incidence of these findings in the global population of subjects with Williams syndrome but also to identify the children who are at risk for developing acute neurological signs.