A single pathophysiological mechanism of Chiari Type I malformations (CM-I) has been a topic of debate. To help better understand CM-I, the authors review disorders known to be associated with CM-I. The primary methodology found among most of them is deformation of the posterior cranial fossa, usually with subsequent decrease in volume. Other mechanisms exist as well, which can be categorized as either congenital or acquired. In understanding the relationship of such disorders with CM-I, we may gain further insight into the process by which cerebellar tonsillar herniation occurs. Some of these pathologies appear to be true associations, but many appear to be spurious.
Marios Loukas, Brian J. Shayota, Kim Oelhafen, Joseph H. Miller, Joshua J. Chern, R. Shane Tubbs and W. Jerry Oakes
R. Shane Tubbs, Cuong J. Bui, Marios Loukas, Mohammadali M. Shoja and W. Jerry Oakes
The authors report on symptomatic patients with myelomeningocele (MMC) and lipomyelomeningocele (LMMC) who were found to have changes in their lumbosacral angle (LSA) corresponding to the onset of symptoms indicative of a tethered spinal cord.
The authors review data obtained in these two cohorts of patients and compare the LSAs measured in the perinatal period with those seen when the patients presented with symptoms of a tethered spinal cord.
Children with LMMC, roughly one third of studied cases, were symptomatic due to a tethered spinal cord at their most recent follow-up. In children in whom the MMC was the closed form at birth, 20 of 30 had symptoms that could be indicative of a tethered spinal cord at their most recent follow-up. The LSA was altered in both groups with symptoms.
Signs and symptoms indicative of a tethered spinal cord appear to correspond to increases in the LSA.
Jeffrey P. Blount, R. Shane Tubbs, John C. Wellons III, Leslie Acakpo-Satchivi, David Bauer and W. Jerry Oakes
✓ In certain highly selected circumstances, division of a distally nonfunctional or dysfunctional cord can be a means of definitive untethering that spares and protects more rostral neurological function and results in definitive untethering. The authors reviewed their institutional experience with such cases and evaluated the limited literature. Based on their experience, treatment can be effective in carefully selected patients who undergo spinal cord transection, and the rate of repetitive tethered spinal cord can be decreased. Although uncommon, spinal cord transection appears to be an effective therapy in carefully selected patents with symptoms of repetitive cord tethering.
Cuong J. Bui, R. Shane Tubbs and W. Jerry Oakes
✓The treatment of a patient with symptoms of a tethered spinal cord and in whom a fatty infiltrated terminal filum is found is controversial. The authors review their experience and the literature regarding this aspect of occult spinal dysraphism. From experience, transection of a fatty terminal filum in patients with symptoms related to excessive caudal cord tension is a minor procedure that generally yields good results. The most problematic issue in the literature is what patients and symptoms are best suited to surgical treatment.
Jeffrey P. Blount, W. Jerry Oakes, R. Shane Tubbs and Robin P. Humphreys
✓ Intracranial aneurysms are rare in children, and their origins and treatment methods tend to be different from those in these same entities in adults. These lesions tend to be congenital or to have an infectious or traumatic origin. In the current paper the authors trace the historical evolution of the diagnosis and treatment of intracranial aneurysms in children. Based on the literature, these lesions appear to occur in children in less than 3% of all series. The literature also supports the suggestion that symptoms from these aneurysms are often from mass effect and that giant aneurysms and lesions in the posterior cranial fossa are relatively more common in children than in adults. The termination of the carotid artery and the anterior cerebral artery seem to be disproportionately common sites of aneurysm formation in this cohort. Interestingly, surgical outcomes in children appear to be moderately better than in adults. Based on the literature, the claim can be made that a multidisciplinary approach to the management of such aneurysms can yield good outcomes in a very high percentage of children treated.
Jeffrey P. Blount, W. Jerry Oakes, R. Shane Tubbs and Robin P. Humphreys
✓ Vein of Galen aneurysmal malformations are a mixed group of lesions characterized by an abnormal fistula between abnormal distal branches of the choroidal and/or posterior cerebral arteries and the great vein of Galen. In this paper the authors trace the historical evolution of the current approach to diagnosis and treatment, and the literature is reviewed comprehensively. During the historical era, vein of Galen malformations were described in individual case reports and an early classification system was developed. In the early era of treatment, open surgery was the preferred approach, although morbidity and mortality rates were high. The development of neurointerventional techniques allowed the introduction of occlusive materials into the fistula, with pronounced improvements in clinical outcome.
Jeffrey P. Blount, R. Shane Tubbs, W. Jerry Oakes and Robin P. Humphreys
✓ Arteriovenous malformations (AVMs) are the most common cause of intracerebral hemorrhage in children. In this paper the authors trace the historical evolution of the recognition, diagnosis, and treatment of pediatric intracerebral AVMs, and they summarize the contemporary approach and current controversies surrounding treatment of these lesions. Important distinctions between adult and pediatric AVMs are emphasized.
Michael J. Rauzzino, R. Shane Tubbs, Eben Alexander III, Paul A. Grabb and W. Jerry Oakes
Neurenteric cysts are infrequently reported congenital abnormalities believed to be derived from an abnormal connection between the primitive endoderm and ectoderm. The authors report a series of 13 patients treated over a 50-year period.
Of the 13 patients, seven were female and six were male. Their ages at presentation ranged widely from 5 weeks to 52 years of age. Children presented more commonly with cutaneous stigmata of occult spinal dysraphism (OSD) whereas adults presented primarily with pain. Neurological deficit as a presenting symptom was less common in our series, a finding that reflects the slow growth of these lesions. In all but one patient some form of vertebral anomaly was associated with the cystic lesions, including two patients with Klippel–Feil abnormalities. There was a high incidence of associated forms of OSD including split cord malformation, lipoma, dermal sinus tract, and tethered spinal cord. In previous reports the authors have suggested that neurenteric cysts are more common in the cervical region and in a position ventral to the cord. In the present series these cysts most commonly occurred as intradural, extramedullary masses in the thoracolumbar region, situated dorsal to the spinal cord. The median follow-up period was 7.5 years, and postoperative outcome reflected a patient's preoperative neurological status; in no patient was outcome worsened due to surgery.
Complete excision of the neurenteric cyst remains the treatment of choice, as subtotal excision is associated with recurrence.