Asma Q. Fischer

Transcranial Doppler and Real-Time Cranial Sonography in Neonatal Hydrocephalus

Nine hydrocephalic infants who were less than 1 year old and 7 age-matched control subjects were examined by real-time and transcranial Doppler sonography to evaluate cerebral blood flow and to correlate it to ventricular size. These 16 infants were placed in one of three groups: infants in group 1 (n = 7) had a normal ventricular size, infants in group 2 (n = 3) had a progressively increasing ventricular size, and infants in group 3 (n = 6) had ventriculomegaly with either stable or decreasing ventricular size or a functioning ventriculoperitoneal shunt. All scans performed on group-2 infants showed markedly increased ventricular size and increased pulsatility index, while those on group-1 infants showed a normal ventricular size and pulsatility index. However, the scans of group-3 infants revealed increased ventricular size and normal pulsatility index. Regression analysis of the data showed rather weak correlations between ventricular size and pulsatility index for all groups. The regression data suggest that ventricular size is not the main determinant of cerebral blood flow in the neonate with hydrocephalus and that intracranial pressure may be a more critical factor. These data suggest that pulsatility index, as measured by transcranial Doppler, can be clinically more important than just the anatomical data alone in the evaluation of hydrocephaly. This points to a possible use of transcranial Doppler sonography in the evaluation of hydrocephalic patients for placement of ventriculoperitoneal shunts. (J Child Neurol 1989;4:64-69).

The Effect of Sleep on Intracranial Hemodynamics: A Transcranial Doppler Study

The effect of sleep on intracranial blood flow velocities has not been reported in children or adults, even though blood flow velocities are evaluated for clinical purposes during both sleep and wakefulness. We report the effect of sleep on intracranial blood flow velocities of 11 healthy individuals (five children and six adults) who were monitored by polysomnography and transcranial Doppler sonography (TCD). Thirty-three TCDs were obtained on middle cerebral arteries. Before sleep, during non-rapid-eye-movement sleep, and after sleep, measurements of systolic, end diastolic, and mean flow velocities were obtained by TCD. Pulse oximetry and end tidal carbon dioxide were monitored during each 8-hour polysomnogram. The before-sleep blood flow velocity values were compared to sleep and after-sleep values in children and adults separately using ANOVA. A significant decrease in the blood flow velocities was noted during sleep compared to before-sleep values in both children (P < .05) and adults (P < .01). The blood flow velocities after sleep were also decreased compared to before-sleep values. This study shows that sleep reduces blood flow velocities in both children and adults. A decrease in blood flow velocities during normal sleep should be taken into account when interpreting TCDs in patients. (J Child Neurol 1991;6:155-158).

Comparative Neuroimaging With Pathologic Correlates in Alexander's Disease

We describe a case of pathologically confirmed Alexanders disease in which serial cranial ultrasound studies demonstrated unique findings of enlarging subependymal cysts with evolving periventricular hyperechogenicity. Computed tomographic scan of the head showed low attenuation of the periventricular white matter and centrum semiovale. Magnetic resonance imaging (MRI) demonstrated diffuse, confluent high signal predominantly in frontal white matter. These imaging modalities, particularly cranial ultrasound and MRI, may be useful tools in the diagnostic evaluation of children with degenerative neurologic disease, megalencephaly, and suspected Alexanders disease. (J Child Neurol 1990;5:248-252).

Citrobacter freundii: a newly reported cause of pyomyositis.

Pyomyositis has been uncommonly reported in temperature climates, but is being recognized with increasing frequency. The most common etiologic agent is Staphylococcus aureus, although other pathogens have been rarely implicated. The authors describe the first case of pyomyositis caused by Citrobacter freundii. Because of the rarity of this disease in North America, it is often initially misdiagnosed. Neuromuscular sonography, a non-invasive imaging technique, identified the muscle abscess in this patient.

Joubert Syndrome: Early Diagnosis by Recognition of the Behavioral Phenotype and Confirmation by Cranial Sonography

Our experience with two children with Joubert syndrome demonstrates how the diagnosis, if suspected by recognition of the behavioral phenotype, can rapidly be made by employing cranial sonography. This technique also may afford prenatal diagnosis of the syndrome in future siblings of confirmed cases. We have produced an educational videotape demonstrating the dynamic behavior of these patients. It is our hope that increased familiarity with the behavior phenotype through this report and through distribution of the videotape will lead to early and accurate diagnosis of further cases of this syndrome. (J Child Neurol 1988;3:247-249).

The Evolution of Ischemic Cerebral Infarction in Infancy: A Sonographic Evaluation

Cranial sonography provides a noninvasive, portable method for imaging the infant brain. This study describes the time-dependent, sonographic findings of infantile cerebral infarction, as well as computed tomographic (CT) scan and neuropathologic confirmation. Three hundred ninety-five infants under 18 months of age were sonogrammed over a period of 18 months. Three infants were diagnosed by cranial sonography and confirmed by CT scan and/or autopsy to have acute ischemic cerebral infarcts. The cases were followed with serial cranial sonograms for up to 18 months of age. The acute sonographic findings included a hyperechoic zone around the infarcted tissue. The subacute infarct had a checkerboard pattern, while the chronic infarcts were anechoic. (J Child Neurol 1988;3:105-109).

Cerebral vasospasm in childhood migraine during the intermigrainous period.

Background and Purpose. The aims of this study were to evaluate the changes in intracranial hemodynamics and assess the presence of vasospasm in children with migraine during the intermigrainous period. Methods. Transcranial Doppler (TCD) sonography findings, clinical examinations, and the vasospastic index of Lindegaard were analyzed for children who fulfilled the criteria for childhood migraine. The significance of the presence of vasospasm and abnormal hemodynamics were statistically analyzed using the normal approximation to the binomial test method. TCD sonography was performed using the standard published techniques for children. Results. Sixty‐two patients between the ages of 5 and 17 years who had undergone at least one TCD sonographic examination were selected for this study. A total of 113 TCD sonographic examinations were performed on the patients. Elevated mean blood flow velocities were found in 23 of 62 patients (37%) (P< .001). Early vasospasm was found in 4 of 62 patients (6.5%) (P< .001). Bruits were noted in 35 of 62 patients (56%). Conclusions. This study raises the possibility of cerebral vasospasm in the intermigrainous period in childhood migraine. Further studies are needed to elaborate on the pathophysiology of cerebrovascular behavior during this period. These findings may have a significant impact on the current clinical treatment of childhood migraine.

Color Flow Imaging in Neurosonology: Technical Background and Clinical Applications

DOI: http://dx.doi.org/10.5915/20-4-13296 This paper summarizes the technical background and current clinical applications of color flow imaging in neurosonology. The criteria for interpretation along with our experience with color flow imaging of the carotid arteries and the intracranial vessels of neonates is presented.

Evaluation of congenital extracranial masses by waterpath sonography

Congenital scalp masses pose a diagnostic and management challenge. In the past the relationship of the lesion to the skull and intracranial contents have been assessed by skull x-rays and computed cranial tomography. Waterpath sonography is a non-invasive technique that utilizes no ionizing radiation for evaluating and monitoring congenital scalp masses. In two illustrative cases this method of imaging assisted in assessing the size, contents, and relationship of the congenital scalp masses to the intracranial contents. It enabled the surgeon to anticipate the avascular cystic nature of the congenital scalp masses, the intact underlying calvarium, and non-violation of the CSF pathways prior to surgery. The technique was also useful for monitoring progress after surgery.

The Ultrasound Appearance of Early Periventricular Leukomalacia with Neuropathologic Correlates

DOI: http://dx.doi.org/10.5915/17-1-12734 Periventricular leukomalacia is a necrotic lesion of the cerebral white matter. It is seen in premature infants weighing 1000-1900 grams at birth, who have cardiorespiratory disturbances early in life and survive more than a week. It is characterized by necrosis of the periventricular axons adjacent to the lateral margins of the lateral ventricles. Premorbid recognition of this entity has been facilitated by the use of cranial ultrasound. Two types of lesions have been described sonographically: porencephalic and hemorrhagic. The former is anechoic and the latter hyperechoic; both are located periventricularly. We present a third type of sonographic pattern associated with early. non-hemorrhagic periventricular leukomalacia. This sonographic pattern differs from those previously described. The cranial ultrasound and neuroropathologic findings will be presented in two premature infants.