Infantile hydrocephalus: brain sonography as an effective tool for diagnosis and follow-up

Role of Endoscopy in Treatment of Complex Hydrocephalus in Children

Complex hydrocephalus or loculated hydrocephalus is a challenging problem in the field of pediatric neurosurgery. Early diagnosis and treatment are paramount in order to ensure success of treatment. Therefore, alertness is required among pediatricians who are dealing with premature children and children having meningitis and/or intraventricular hemorrhage. Disproportionate hydrocephalic changes in CT scan of the brain are suspicious, whereas gadolinium-enhanced multiplanar MR imaging (axial, sagittal, and coronal) is the best diagnostic modality. The definitive treatment is surgical, yet the approach remains a matter of debate. Cyst fenestration, communicating the isolated compartments together and with the ventricular system, is the main strategy of treatment. Cyst fenestration can be performed through either microsurgery or endoscopy, in order to improve the hydrocephalus, decrease number of shunts, and reduce shunt revision rates. However, the endoscopic procedure has an advantage over microsurgery of being simple and minimally invasive. It is evident that uniloculated hydrocephalus carries better prognosis than multiloculated hydrocephalus; this can be attributed to the initial pathological disease contributing to the ventricular compartmentalization. Because of the bad prognosis in multiloculated hydrocephalus, and because there are few numbers of patients available in any given center, a multicentric prospective study with long-term follow-up evaluating the results of outcome and quality of life is warranted.

Brain contrast-enhanced ultrasonography and elastography in infants

Advanced ultrasound techniques, including brain contrast-enhanced ultrasonography and elastography, are increasingly being explored to better understand infant brain health. While conventional brain ultrasonography provides a convenient, noninvasive means of assessing major intracranial pathologies, its value in revealing functional and physiologic insights into the brain lags behind advanced imaging techniques such as magnetic resonance imaging. In this regard, contrast-enhanced ultrasonography provides highly precise functional information on macrovascular and microvascular perfusion, while brain elastography offers information on brain stiffness that may be associated with relevant physiological factors of diagnostic, therapeutic, and/or prognostic utility. This review details the technical background, current understanding and utility, and future directions of these two emerging advanced ultrasound techniques for neonatal brain applications.

Endoscopic cyst fenestration in the treatment of uniloculated hydrocephalus in children

OBJECT

The treatment of uniloculated hydrocephalus is a difficult problem in pediatric neurosurgery. Definitive treatment is surgical, yet the approach remains controversial. This study evaluates the role of endoscopic cyst fenestration (ECF) in the management of this disease.

METHODS

Thirty-one pediatric patients with uniloculated hydrocephalus who underwent endoscopic surgery, performed by the author, between May 1999 and December 2010 constitute the patient group for this study. The patients included 17 boys and 14 girls, with ages ranging from 5 months to 5 years (mean 22.9 months). Patients with multiloculated hydrocephalus were not included. The patients' charts were reviewed for demographic data, radiological findings, information regarding morbidity, improvement of hydrocephalus, incidence of recurrence, shunt dependency, and the need for shunt revision.

RESULTS

Neuroepithelial cysts were the most common cause (17 cases), followed by postoperative gliosis due to previous shunt infection (9 cases), intraventricular hemorrhage (3 cases), and meningitis (2 cases). Multiplanar MRI was reliable in making the diagnosis and is indicated if CT shows disproportionate hydrocephalus. Surgical treatment included ECF (31 cases), endoscopic revision of malfunctioning preexisting shunts (9 cases), endoscopic third ventriculostomy (4 cases), and placement of a new shunt (3 cases). Endoscopic cyst fenestration was easily performed in all the cases, with devascularization of the cyst wall by coagulation to prevent recurrence. Improvement of hydrocephalus was observed in 26 cases (83.9%). Among the group of patients without prior shunts (22 cases), 3 patients (13.6%) required repeat ECF and 3 patients (13.6%) required placement of a shunt (new shunt placement). In the 9 patients with preexisting shunts, endoscopy reduced the mean rate of shunt revision from 2.7 revisions per year before fenestration to 0.25 per year after fenestration. Four of these 9 patients had multiple shunts, which could be converted to a single shunt; however, repeat ECF was necessary in all 9 patients. With a mean follow-up duration of 4.3 years, none of the patients with a prior shunt was able to become shunt-independent, whereas 86.4% of patients without a prior shunt were able to avoid shunt placement. Endoscopic complications were reversible (unilateral subdural effusion in 5 cases, minor arterial bleeding in 2 cases, CSF leakage in 1 case), and there was no death (0%).

CONCLUSIONS

Endoscopic cyst fenestration is recommended in the treatment of uniloculated hydrocephalus because it is effective, simple, minimally invasive, and associated with low morbidity and mortality rates. The fact that all previously shunt-treated patients needed repeat ECF and that none of these patients was able to become shunt-independent makes it clear that uniloculated hydrocephalus due to postoperative gliosis induced by previous shunt infection carries the worst prognosis.

Brain abscess in a neonate: an unusual presentation

BACKGROUND

Neonatal brain abscesses are very rare and their clinical presentation is specific for this age group. They usually occur as a complication of bacterial meningitis or septicemia. They are most often caused by gram-negative organisms, and mortality and morbidity are still significant in this particular group of patients in spite of antibiotics and modern radiological tools.

METHODS

We report an unusual case of a multiloculated brain abscess in a term neonate caused by Staphylococcus aureus. The abscess developed in the absence of trauma, prior surgery, cyanotic heart disease, mother's disease, or immune defect. The onset of infection in this case was not clear and image features mimicked a brain tumor in the initial evaluation. The infant was successfully treated by primary surgical excision of the lesion and a 6-week total course of intravenous antibiotics.

CONCLUSION

The interest of this case lies in the rarity of the causative organism and the atypical features of clinical and neurological images in a term neonate.

Transcranial color-coded Doppler ultrasonography for evaluation of children with hydrocephalus

OBJECT

Hydrocephalus is a common disease process. Transcranial color-coded Doppler (TCCD) ultrasonography is an accepted noninvasive method with which to quantify intracranial blood flow in adults and children. The authors studied the applications of TCCD ultrasonography and the alterations of the flow velocity of the cerebral arteries in children with hydrocephalus.

METHODS

One hundred thirty-five children were divided into three groups: Group 1 comprised 40 infants with asymptomatic hydrocephalus who had well-functioning ventriculoperitoneal (VP) shunts; Group 2 comprised 10 children with symptomatic hydrocephalus who had malfunctioning shunts that were replaced; and Group 3 was a control group of 85 healthy infants. All patients underwent sequential measurements of cerebral blood flow (CBF) velocities (systolic and diastolic velocities) and resistivity index (RI). One group of patients underwent functional tests (compression of the anterior fontanelle and CO2 vasoreactivity) to determine hemodynamic changes in cerebral circulation. A significant statistical change in RI measurements, end diastolic CBF velocity, and percentage of change in RI was shown in patients with malfunctioning shunts, and in infants with a well-functioning VP shunt vasomotor reactivity was severely reduced.

CONCLUSIONS

Transcranial color-coded Doppler ultrasonography can be used to perform follow-up assessments of normal and malfunctioning shunts in children with hydrocephalus; the functional tests are a noninvasive tool for evaluating the cerebral compliance and the cerebral autoregulation in infants with hydrocephalus. The autoregulatory capacity may partly or completely be lost in cases of long-term shunt-treated hydrocephalus, and loss of cerebral vasoreactivity may be responsible for long-term deficits commonly observed in children, which help explain some of symptoms related to slit ventricles.

Cerebral mantle thickness: a measurement useful in anatomic diagnosis of fetal ventriculomegaly

The ultrasonographic diagnosis of cerebral ventriculomegaly carries grave implications, in that affected fetuses may suffer abnormal postnatal development or therapeutic abortion. It is important for pathologists to corroborate the clinical diagnosis, but because diagnostic methodologies and criteria differ so radically, this can be problematic. The clinical diagnosis is made primarily by serial ultrasound examinations of the cerebral ventricles, spaces that can be altered postmortem, particularly when the brain is autolysed or deformed artifactually. We therefore sought to learn if examination of tissue, rather than spaces, can identify accurately those fetuses diagnosed with cerebral ventriculomegaly by prenatal ultrasound. The thickness of the cerebral mantle was obtained in 100 control fetuses aged 14 to 26 postmenstrual weeks. Statistical analysis revealed significant correlation of cerebral mantle thickness with crown-rump length, foot length, and head circumference. Twenty fetuses diagnosed with ventriculomegaly showed mantle thicknesses that were less than the control mean. In a few cases, mantle thickness fell between the mean and -1 SD; in several others, thickness was diminished by -1 SD to -2 SD; in one-half of cases, mantle thickness was 2 SDs or more below the expected mean. Head circumference was within 2 SDs of the control mean in most cases, and increased beyond 2 SDs in only two cases. Head circumference is an unreliable indicator of ventriculomegaly in the midgestational fetus. By contrast, cerebral mantle thickness is a simple and useful way of corroborating ultrasonographic diagnoses at autopsy and may also prove useful in clinical settings.

The use of transcranial Doppler ultrasonography as a method of assessing intracranial pressure in hydrocephalic children

Previous studies in children have shown a strong correlation between raised intracranial pressure (RICP) and the Gosling pulsatility index (PI) as determined by transcranial Doppler ultrasonography (TCD). This diagnostic modality can, therefore, be used as a non-invasive method for the indirect evaluation of shunt function in children with hydrocephalus. Transcranial Doppler waveform analyses were done in 15 children with hydrocephalus, before and after insertion of a ventriculo-peritoneal shunt. All had clinical evidence of raised intracranial pressure (ICP) prior to surgery. CT had demonstrated dilated ventricles and, in some, additional features of RICP. Fifteen children without clinical and CT evidence of hydrocephalus were examined in an identical manner to act as a control group. The results clearly demonstrated that TCD may be a useful, non-invasive means of assessing the need for a cerebrospinal fluid (CSF) diversionary procedure and also for follow-up and monitoring.