David S. Knierim

Predictive value of proton magnetic resonance spectroscopy in pediatric closed head injury

We studied 26 infants (1-18 months old) and 27 children (18 months or older) with acute nonaccidental (n = 21) or other forms (n = 32) of traumatic brain injury using clinical rating scales, a 15-point MRI scoring system, and occipital gray matter short-echo proton MRS. We compared the differences between the acutely determined variables (metabolite ratios and the presence of lactate) and 6- to 12-month outcomes. The metabolite ratios were abnormal (lower NAA/Cre or NAA/Cho; higher Cho/Cre) in patients with a poor outcome. Lactate was evident in 91% of infants and 80% of children with poor outcomes; none of the patients with a good outcome had lactate. At best, the clinical variables alone predicted the outcome in 77% of infants and 86% of children, and lactate alone predicted the outcome in 96% of infants and 96% of children. No further improvement in outcome prediction was observed when the lactate variable was combined with MRI ratios or clinical variables. The findings of spectral sampling in areas of brain not directly injured reflected the effects of global metabolic changes. Proton MRS provides objective data early after traumatic brain injury that can improve the ability to predict long-term neurologic outcome.

Choroid Plexus Tumors in Infants

Choroid plexus tumors continue to be a challenge in their diagnosis, treatment, and associated conditions that occur in perioperative management. Improved radiographic techniques have recently aided surgical planning, and recent developments in operating room technology are having an impact on the favorable outcome of these patients. Cerebrospinal fluid dynamics often add to the complexity of the perioperative management.

Mild head injury in children: Identification, clinical evaluation, neuroimaging, and disposition

Pediatric head injury presents in various degrees of severity. Early intervention in the patient with a severe head injury is the key to preventing secondary central nervous system damage. Patients with a head injury are easily identified, often by clinical examination alone. However, patients with a mild head injury present a challenge to practitioners, particularly in identification, knowing what is important in the clinical evaluation, deciding whether to use neuroimaging, and knowing where to send the child for observation. Use of the Glasgow Coma Score, primary survey, and identification of historic and clinical features that are suggestive of severe head injury may guide pediatric nurse practitioners in providing appropriate medical care and disposition.

Stereotactic Localization of Deep-Seated Arteriovenous Malformations in the Functional Area

The authors approached 5 arteriovenous malformations (AVMs) located deep in functional areas of the cortex with major draining veins found in the mesial hemisphere by using the stereotactic method. This procedure is a useful adjunct to total resection of these AVMs. No mortality or significant morbidity was noted after the surgical procedure. The authors believe that direct attack on AVMs in areas of critical function is the procedure of choice in order to preserve neurological function.

Syringomyelia Associated with Tethered Cord Syndrome

The pathogenesis and dynamic pathophysiology of syringomyelia are not fully understood. Pathogenetically, syringomyelia is categorized as either a communicating syrinx (hydromyelia) or a noncommunicating syrinx. The latter category includes those caused by (1) contusion, (2) compression, (3) traction, (4) arachnoiditis, (5) tumors, and (6) ischemia. Syringomyelia located in the lumbosacral cord is likely derived from the same types of pathogenesis. The signs and symptoms of lumbosacral syringomyelia are similar to those of tethered cord syndrome (TCS), caused by the lesion being in the central portion of the spinal cord. Neurological deficits in these disorders are motor and sensory deficits in the lower limbs, incontinence, and musculoskeletal deformities. Syringomyelia associated with TCS is a unique combination and difficult to correlate because TCS is a metabolic functional disorder and syringomyelia is an anatomic functional criterion. The authors divided a series of syrinx patients into three groups: (1) those with lumbosacral syringomyelia associated with tethered spinal cord, in which the spinal cord is anchored by an inelastic filum; (2) those with low thoracic and lumbar syringomyelia associated with TCS, in which a lipoma, lipomyelomeningocele, or meningocele manque is the mechanical cause of tethering; and (3) those with a syrinx in the lower thoracic and lumbosacral cord without evidence of a tethered cord. The syrinxes in the patients in all three groups were considered to be isolated from the fourth ventricle cord. The authors’ observations include: (1) The incidence of lumbosacral syrinx in tethered spinal cord patients is much lower than that in TCS patients; (2) The group 1 patients have milder neurological symptomatology than do the group 2 patients. The degree of improvement in the neurological conditions and physical activities are much greater in group 1 than in group 2 patients; (3) Group 3 patients tend to have more serious neurological deficits associated with hydrocephalus and severe musculoskeletal deformities. Based on these facts, the authors postulate that syrinxes should be drained in cases in which the signs and symptoms suggest that the neurological deficits are more significant than those for TCS alone.