Diastematobulbia type II without associated dermoid tumor: case report.

Split cord malformation (SCM) is a term used for all double spinal cords. It represents 3.8%-5% of spinal dysraphisms. Pang et al.'s embryological theory proposes the formation of an "accessory neurenteric canal" that communicates with the yolk sac and amnion. To the authors' knowledge, only three cases of diastematobulbia (basicranial SCM) associated with a spur or dermoid have been reported in the literature.The case patient is a newborn girl with an occipitocervical meningocele and dermal sinus associated with an anomaly of notochordal development in the transition between the medulla oblongata and the spinal cord (diastematobulbia) without a bony septum or dermoid cyst. The patient also has agenesis of the atlas and an absence of corticospinal tract decussation. This patient underwent reconstruction of the occipital meningocele and dermal sinus excision.To the authors' knowledge, this is the first described case of type II diastematobulbia (basicranial SCM), without a dermoid cyst. The authors analyzed the embryological errors present in the case patient and considered the option of further surgical treatment depending on the evolution of the patient's condition. At the time of this report, the patient had shown normal psychomotor development. However, this fact may only be due to the patient's young age. Considering that after initial untethering the patient remained clinically asymptomatic, conservative and close surveillance has been and continues to be the proposed treatment.

Complex Cervicomedullary Junction Malformation and Hypoplastic Cerebellar Tonsils following Fetal Repair of Myelomeningocele: Case Report and Literature Review.

BACKGROUND: Following the publication of the Management of Myelomeningocele study (MOMS), fetal repair of myelomeningocele (MMC) has become increasingly prevalent worldwide. However, limited case presentations exist illustrating the potential mechanical and embryological effects of fetal repair. We present a unique case report of a complex embryological cervicomedullary junction (CMJ) malformation and cerebellar hypoplasia following fetal repair of MMC. CASE DESCRIPTION: A 1-day-old female was referred to the paediatric neurosurgical team after having successful surgical intrauterine closure of MMC abroad at 25 weeks gestation. The patient was born by emergency caesarean section at 33 weeks gestation and had a ventricular-peritoneal shunt inserted at 25 days old due to resulting hydrocephalus. Neonatal MRI scans revealed a complex number of malformations that included a split cord located at the CMJ, hypoplasia of the cerebellum and vermis, and a Chiari type II malformation. CONCLUSION: It is possible that the clefting of the upper cervical spinal cord was undetected at preoperative MRI; however, this is unlikely given the antenatal images. It is our hypothesis that the malformation may have exhibited mechanical change after the repair, as the preoperative MRI showed only a Chiari II malformation without any of the complex abnormalities being present and the split cord was already there but not obvious. There are no existing reports of such a complex malformation following antenatal surgery in the literature. This should be further explored as more cases and trials become available.

Isolated neonatal bilateral vocal cord paralysis revealing a unilateral medullary defect: a case report.

BACKGROUND: Congenital bilateral vocal cord paralysis is a rare occurrence. Approximately half the cases are associated with a major comorbidity, usually neurological, neuromuscular or malformative. CASE PRESENTATION: In a male newborn, respiratory distress syndrome and stridor were observed immediately following birth. The cause was bilateral vocal cord paralysis in the adducted position. Neuroradiological investigation revealed a unilateral discontinuity between the upper pons and the right medulla oblongata. Hypoplasia of the right posterior hemiarches of C1-C2 and the right exo-occipital bone was observed, as was a small clivus. MR angiography showed the absence of the distal right vertebral artery, with hypoplasia and parietal irregularities of the proximal segments. Respiratory autonomy was not obtained despite endoscopic laser cordotomy, corticosteroid therapy and nasal continuous positive airway pressure. The infant died at the age of 4 weeks after treatment was limited to comfort care. CONCLUSIONS: A medullary lesion is an exceptional cause of congenital bilateral vocal cord paralysis. The strictly unilateral neurological and vascular defect and the absence of associated intracranial or extracranial malformation make this clinical case unique and suggest a disruptive mechanism. This case also highlights the help provided by advanced neuroimaging techniques, i.e. fibre tracking using diffusion tensor imaging, in the decision-making process.

DSCAM deficiency causes loss of pre-inspiratory neuron synchroneity and perinatal death.

Down syndrome cell adhesion molecule (DSCAM) is a neural adhesion molecule that plays diverse roles in neural development. We disrupted the Dscam locus in mice and found that the null mutants (Dscam(-/-)) died within 24 h after birth. Whole-body plethysmography showed irregular respiration and lower ventilatory response to hypercapnia in the null mutants. Furthermore, a medulla-spinal cord preparation of Dscam(-/-) mice showed that the C4 ventral root activity, which drives diaphragm contraction for inspiration, had an irregular rhythm with frequent apneas. Optical imaging of the preparation using voltage-sensitive dye revealed that the pre-inspiratory neurons located in the rostral ventrolateral medulla and belonging to the rhythm generator for respiration, lost their synchroneity in Dscam(-/-) mice. Dscam(+/-) mice, which survived to adulthood without any overt abnormalities, also showed irregular respiration but milder than Dscam(-/-) mice. These results suggest that DSCAM plays a critical role in central respiratory regulation in a dosage-dependent manner.

Intramedullary cervical neurenteric cyst mimicking an abscess.

We describe a cervical intramedullary neurenteric cyst in a 12-year-old male patient who presented with gradual onset and progressively worsening neck pain, spastic quadriparesis and impaired sensation in the C(2) dermatome. MR imaging revealed a well-defined peripherally enhancing cystic intramedullary lesion with a posteroinferior enhancing nodule at the C(2)-C(3) level mimicking an abscess. There was no evidence of spinal dysraphism. The lesion was completely resected through a posterior approach and the patient showed radical improvement in his symptomatology. At follow-up after 3 years, he was asymptomatic and the MR imaging showed no evidence of any residual or recurrent cyst. The case presented here is unique, since a spinal neurenteric cyst showing intense peripheral contrast enhancement mimicking an abscess is unusual. The radiological features, pathogenesis and surgical considerations in cervical intramedullary neurenteric cysts are discussed and the relevant literature is briefly reviewed.

A developmental classification of malformations of the brainstem.

OBJECTIVE: With advances in imaging and genetics, malformations of the brainstem are being more commonly identified. We describe and classify brainstem anomalies in 138 patients ascertained over a period of 10 years METHODS: Magnetic resonance imaging studies and, where available, clinical records of the patients were retrospectively reviewed. Malformations were segregated according to magnetic resonance findings and classified when possible by embryological mechanisms RESULTS: The most common location for anomalies was the pons, which was involved in 114 patients. The midbrain was involved in 45 patients, whereas the medulla was involved in 14. In 53 patients, more than 1 region was affected (all 3 regions in 6 patients, midbrain and pons in 39, and medulla and pons in 8). The malformations were divided into four groups: (1) malformations with abnormal brainstem segmentation, (2) malformations with segmental hypoplasia, (3) postsegmentation malformations, and (4) malformations associated with abnormal cortical organization INTERPRETATION: The malformations of the brainstem identified in this study were diverse and complex. This proposed classification organizes them into groupings based on known genetics and embryological events. Use of this system will help clinicians and scientists to better understand these disorders and, ultimately, to better counsel families of affected patients.

MR imaging features of brain stem hypoplasia in familial horizontal gaze palsy and scoliosis.

We report the case of a child with horizontal gaze palsy, pendular nystagmus, and discrete thoracolumbar scoliosis. MR imaging of the brain depicted pons hypoplasia with an absence of the facial colliculi, hypoplasia, butterfly configuration of the medulla, and the presence of a deep midline pontine cleft (split pons sign). These MR imaging findings suggest familial horizontal gaze palsy with progressive kyphoscoliosis, a rare congenital disorder. To the best of our knowledge, MR imaging findings of only 4 similar cases, with or without progressive idiopathic scoliosis, have been reported. We discuss the pathogenesis substratum of this entity. Early recognition of this rare entity is important if supportive therapeutic measures in progressive scoliosis are to be applied.

Alexander disease: ventricular garlands and abnormalities of the medulla and spinal cord.

BACKGROUND: Alexander disease is most commonly associated with macrocephaly and, on MRI, a leukoencephalopathy with frontal preponderance. The disease is caused by mutation of the GFAP gene. Clinical and MRI phenotypic variation have been increasingly recognized. METHODS: The authors studied seven patients with Alexander disease, diagnosed based on mutations in the GFAP gene, who presented unusual MRI findings. The authors reviewed clinical history, MRI abnormalities, and GFAP mutations. RESULTS: All patients had juvenile disease onset with signs of brainstem or spinal cord dysfunction. None of the patients had a macrocephaly. The MRI abnormalities were dominated by medulla and spinal cord abnormalities, either signal abnormalities or atrophy. One patient had only minor cerebral white matter abnormalities. A peculiar finding was the presence of a kind of garland along the ventricular wall in four patients. Three patients had an unusual GFAP mutation, one of which was a duplication mutation of two amino acids, and one an insertion deletion. CONCLUSION: Signal abnormalities or atrophy of the medulla or spinal cord on MRI are sufficient to warrant DNA analysis for Alexander disease. Ventricular garlands constitute a new sign of the disease. Unusual phenotypes of Alexander disease are found among patients with late onset and protracted disease course.

Sleep-disordered breathing in patients with Chiari malformation: improvement after surgery.

Sixteen consecutive patients with Arnold-Chiari malformation type I and syringomyelia underwent full-night polysomnography (PSG). Sleep apnea syndrome (apnea-hypopnea index > 10) was diagnosed in 12 of 16 patients with 48% of central apneas. In six patients with sleep apnea syndrome, PSG was repeated an average of 203 days after decompression surgery. Postoperative PSG showed a decrease in the central apnea index from 14.9 +/- 5.5 to 1.3 +/- 0.6 (p = 0.03).

Adverse effects of prenatal tobacco smoke exposure on biological parameters of the developing brainstem.

We aimed to study the consequences of chronic exposure to tobacco smoke in utero on the morphological and functional maturation of the brainstem by comparing stillbirths of smoker mothers versus nonsmoker mothers. A total of 42 stillbirths, aged 25-40 gestational weeks, underwent autopsy according to our guidelines (). The brainstem was studied on serial sections and by immunohistochemistry to assay the expression of the EN2 gene, somatostatin (SS) and the tyrosine hydroxylase enzyme (TH). We observed a significant correlation between maternal smoking and sudden intrauterine unexplained death (SIUD), hypoplasia of the ArcN, no immunostaining of the EN2 in the arcuate nucleus (ArcN), and of TH in the locus coeruleus (LC) (P < 0.05). An increased incidence of maternal smoking was also observed in fetuses with SS negativity in the hypoglossus nucleus (HypoglN). Exposure in utero to maternal smoking may strongly interfere with brain biological parameters, giving rise not only to structural developmental abnormalities of the arcuate nucleus, but also to a decrease of noradrenergic activity in the LC, of EN2 gene expression in the ArcN and of SS in the HypoglN.

Pontomedullary disconnection: fetal and neonatal considerations.

The cerebellar and pontocerebellar hypoplasias present a unique challenge when detected in the developing fetus. A diverse aetiology and prognosis make counselling of these families difficult. Advances in fetal imaging allow for more accurate diagnosis and counselling, but postnatal MRI is still required. A case is presented in which cerebellar hypoplasia was detected at 20 weeks gestation. Later fetal imaging provided further information, but a diagnosis of pontomedullary disconnection was not made until the postnatal MRI scan. The clinical findings and possible causes of such pontocerebellar abnormalities are discussed.

Spectrum of malformations of the hindbrain (cerebellum, pons, and medulla) in a cohort of children with high rate of parental consanguinity.

We review 25 patients with a spectrum of hindbrain (cerebellum, pons, and medulla) malformations from a cohort of children with high parental consanguinity rate. Twenty-three of the 25 patients were born to consanguineous parents. The patients were classified in four groups. Eleven patients of 6 families had malformation of the hindbrain and midbrain with molar tooth sign (10 patients of 5 families with typical Joubert syndrome), 5 patients showed severe supratentorial anomalies in addition to the hindbrain malformations, 5 patients had pontocerebellar or cerebellar hypoplasia with anterior horn cell disease in the spinal cord (spinal muscular atrophy), and 4 patients showed malformations affecting predominantly the hindbrain without substantial involvement of other systems. A locus for Joubert syndrome was previously identified on chromosome 9q34.3 in two families, and a second locus on chromosome 11p12-q13.3 in another family. A third Joubert syndrome locus has been mapped at 6q23 and a mutation in the AHI1 gene at this site has been found recently in a further family from this cohort. Delineation of homogeneous subgroups of patients with hindbrain malformations and molecular genetic analysis of these groups may lead to identification of further loci, genes and mutations responsible for the malformations.

Sudden and unexpected fetal death associated with agenesis of the arcuate nucleus in the medulla oblongata.

Abnormalities have been reported in the medullary arcuate nucleus (ARCN) in unexpected late fetal death. They speculated that this developmental anomaly may underlie cardioventilatory abnormalities intrapartum and postpartum. This article describes a case of an unexpected late fetal death associated with absence of the ARCN.

Congenital cleft in the pontomedullary junction.

A 4-month-old boy is reported with complete absence of horizontal gaze. Magnetic resonance imaging revealed a congenital cleft at the pontomedullary junction directed from the right anterior paramedian region toward the posterior midline, sparing the posterior region of the pontine tegmentum and the medulla oblongata. Such clefts are extremely rare, and there is only 1 previous report in the literature.

Direct approach to the ventrolateral medulla for cavernous malformation--case report.

A 49-year-old man presented with symptomatic cavernous malformation in the ventrolateral portion of the medulla oblongata manifesting as left-sided numbness and gait disturbance. Neurological examination disclosed sensory disturbance on the left, cerebellar ataxia, nystagmus, dysphagia, and right hypoglossal nerve paresis. Magnetic resonance imaging revealed a cavernous malformation with hemorrhage occupying the right paramedian field of the medulla oblongata. The patient underwent complete removal of the lesion through vertical incision of the bulging surface of the ventrolateral medulla, anatomically coinciding with the inferior olive. The neurological deficits improved without additional postoperative deficits. This unusual microsurgical approach through a ventrolateral medullary incision permits direct resection of a subpial intrinsic lesion, even on the ventral medulla.