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D Harwood-Nash

Publications and source records attributed to D Harwood-Nash.

17 recordsLinked to original sources
PubMed1998

Cerebellar arteriovenous malformations in children.

We review the presentation, imaging findings and outcome in 18 children with cerebellar arteriovenous malformations (AVM). This group is of particular interest because of the reported poor outcome despite modern imaging and neurosurgical techniques. All children had CT and 15 underwent catheter angiography at presentation. Several of the children in the latter part of the study had MRI. Of the 18 children, 17 presented with a ruptured AVM producing intracranial haemorrhage. The remaining child presented with temporal lobe epilepsy and was shown to have temporal, vermian and cerebellar hemisphere AVM. This child had other stigmata of Osler-Weber-Rendu syndrome. Three other children had pre-existing abnormalities of possible relevance. One had a vascular malformation of the cheek and mandible, one a documented chromosomal abnormality and another a midline cleft upper lip and palate. Six of the 17 children with a ruptured cerebellar AVM died within 7 days of the ictus. Vascular pathology other than an AVM was found in 10 of the 14 children with a ruptured cerebellar AVM who had angiography: 4 intranidal aneurysms, 5 venous aneurysms and 2 cases of venous outflow obstruction (one child having both an aneurysm and obstruction). The severity of clinical presentation was directly related to the size of the acute haematoma, which was a reasonable predictor of outcome.

Adolescent↗
PubMed1997

99mTechnetium HMPAO imaging in children with the Sturge-Weber syndrome: a study of nine cases with CT and MRI correlation.

Demonstration of the full extent of abnormality in patients with the Struge-Weber syndrome (SWS) is important for prognosis and in planning surgery to remove the seizure focus. We compared single-photon emission computed tomography (SPECT), MRI and CT in nine children under the age of 4 years with seizures as part of SWS, in an attempt to determine the optimal method of imaging in different clinical settings. Seven unilateral and two bilateral cases were studied by interictal 99mtechnetium hexamethylpropyleneamineoxime (HMPAO) SPECT, and contrast-enhanced CT and MRI, giving information on 11 abnormal hemispheres. All imaging modalities showed abnormalities in every child. Perfusion imaging showed focal regions of decreased uptake in 9 of 11 (82%) abnormal hemispheres and demonstrated a widespread decrease but no focal defect in 2; it also revealed crossed cerebellar diaschisis in 2 cases. CT demonstrated typical gyriform calcification in 9 of 11 (82%) affected hemispheres. Contrast-enhanced MRI showed more extensive involvement than contrast-enhanced CT in 5 of 11 (45%) cases. The area of hypoperfusion shown by SPECT was smaller than the area of contrast enhancement on MRI in 6 of 11 cases (55%), comparable in 3 (27%) and larger in 2 cases (18%). CT is sufficient to confirm the clinical diagnosis of SWS, but MRI frequently shows more extensive abnormal areas. 99mTc HMPAO imaging is a useful addition when it is important to know the full extent of the disease, for example prior to surgery. It is likely to detect areas of hypoperfusion, representing ischaemic regions, which may act as an epileptogenic focus and may not be shown by CT or MRI.

Adolescent↗
PubMed1996

Abnormal ocular enhancement in Sturge-Weber syndrome: correlation of ocular MR and CT findings with clinical and intracranial imaging findings.

PURPOSE: To estimate the prevalence of abnormal ocular enhancement in children with Sturge-Weber syndrome as detected with MR imaging and CT and to correlate this with the clinical, fundoscopic, and intracranial imaging findings. METHODS: Fifteen children, 4 years old or younger, with Sturge-Weber syndrome were examined with enhanced CT and MR imaging. Eleven children had unilateral intracranial involvement and 4 had bilateral involvement, for a total of 19 abnormal hemispheres and related orbits. The presence of ocular enhancement was compared with the fundoscopic findings independently. Ocular enhancement was correlated with the extent of leptomeningeal disease, the severity of the cutaneous lesion, and the presence of glaucoma by the calculation of likelihood ratios and 95% confidence limits. RESULTS: Seven of the 15 patients had abnormal ocular enhancement, which was present in 10 (53%) of the eyes associated with the 19 abnormal hemispheres. MR imaging showed choroidal hemangioma in 7 of 8 patients in whom hemangiomas were shown at fundoscopy. The likelihood of ocular enhancement was increased with the presence of bilateral disease, extensive facial nevi, and glaucoma; there was no significant correlation with the extent of hemispheric involvement. CONCLUSION: Both enhanced MR imaging and CT can show diffuse choroidal hemangioma in patients with Sturge-Weber syndrome. However, MR imaging is more sensitive and is recommended to aid in the detection of abnormalities with preventable late complications.

Brain↗
PubMed1996

Choroid plexus size in young children with Sturge-Weber syndrome.

PURPOSE: To assess the size of the choroid plexus in young children with unilateral and bilateral Sturge-Weber syndrome. METHODS: Subjects included 15 children 4 years old or younger with Sturge-Weber syndrome. Eleven cases were unilateral and four were bilateral. Unilateral or bilateral involvement was determined by the distribution of abnormal leptomeningeal enhancement on MR images. The diameters of the choroid plexus were measured on contrast-enhanced axial MR images. The choroid plexus of the affected and unaffected sides in these cases were compared with those of 15 age-matched children without Sturge-Weber syndrome who were being examined for seizures. RESULTS: Our results show a wide variation in the size of the choroid plexus in children with Sturge-Weber syndrome; however, plexus associated with a hemisphere affected by Sturge-Weber syndrome were significantly larger than those on the unaffected side and in the age-matched control group. The size of the choroid plexus was positively correlated with the extent of leptomeningeal involvement as demonstrated by abnormal contrast enhancement. CONCLUSION: The choroid plexus is enlarged early in the course of Sturge-Weber syndrome in both unilateral and bilateral cases. There is a positive correlation between choroid plexus size and extent of leptomeningeal involvement in children with Sturge-Weber syndrome.

Child, Preschool↗
PubMed1995

Neuroimaging studies in children with temporal lobectomy.

Twenty-eight children with intractable seizures who subsequently underwent a temporal lobectomy were studied by electroencephalogram (EEG), prolonged video EEG telemetry, computed tomography (CT), magnetic resonance imaging (MRI), and single photon emission computed tomography (SPECT) for the localization of epileptogenic foci. MRI showed abnormalities indicating epileptogenic foci in 21/25 patients and a increased signal intensity in 7/11 patients with mesial temporal sclerosis (MTS). SPECT showed corresponding abnormalities in 17/22 patients, including an interictal decrease in regional cerebral blood flow corresponding to the epileptogenic zone in 15. CT showed localized abnormalities in 16/28. All 12 patients with benign, slow-growing neoplasms showed an abnormality on CT scan. In children, MRI is essential in localizing epileptogenic abnormalities, especially MTS and cortical dysplasia. SPECT contributes to the localization of epileptogenic foci, which are often coincident with EEG abnormalities, particularly in single pathology. CT depicts benign neoplasms with calcification in the temporal lobe, which are likely to provoke complex partial seizures.

Adolescent↗
PubMed1993

Pathology of temporal lobectomy for refractory seizures in children. Review of 20 cases including some unique malformative lesions.

Significant pathological abnormalities were encountered in a series of 20 temporal lobectomies in children with intractable complex partial seizures. In particular, "dual pathology" (mesial temporal sclerosis with other lesions) was found rather than mesial temporal sclerosis as the only lesion. Unusual pathological findings included capillary penetration of neurons in a neuronal heterotopia in one patient, and foci of extensive cortical disorganization in some cases of mixed tumors and gangliogliomas. A high proportion of neuronal migration disorders was also seen with overlapping pathological features between cortical dysplasia and tuberous sclerosis. In this correlative clinical, radiological, electroencephalographic, and pathological study, some of the pathological lesions in children did not fit the classical categories of neoplasia and malformation and transitional forms were rarely encountered.

Adolescent↗
PubMed1993

Pediatric spinal neoplasms.

Magnetic resonance imaging (MRI) is an accurate and noninvasive tool in the evaluation of children with spinal neoplasm. Localization and definition of site and extent of disease for treatment planning, the most important goals of neuroimaging in spinal neoplastic disease, have become more precise with MRI, because all spinal compartments can be seen without the need for subarachnoid puncture. Epidural and contiguous soft tissue disease, and associated vertebral abnormalities such as marrow replacement by metastatic processes, are readily confirmed during the same examination. In children, as in adults, gadolinium-diethylenetriaminepentaacetic acid aids in separating intramedullary neoplasms from associated edema or syrinx, and is essential in the evaluation of intradural-extramedullary spread of neoplasm. MRI is also useful in the exclusion of compressive lesions in children with systemic neoplasms and cord infarction or treatment-related transverse myelopathy.

Adolescent↗
PubMed1992

Magnetic resonance imaging evaluation of delayed myelination in Down syndrome: a case report and review of the literature.

Magnetic resonance imaging has been found to be useful in assessing brain myelination and provides information on brain maturation. The normal pattern of brain myelination conforms to a fixed sequence, with good pathologic and MRI correlation. Neuropathologic analysis of myelination has shown delayed central myelination in Down syndrome. Delayed myelination on MRI in Down syndrome has not previously been reported. We report a case of Down syndrome with a significant delay in myelination as demonstrated on MRI. This 18-month-old infant had brain myelination equivalent to that expected for an 11-month-old infant. To determine the relative incidence, extent of delayed myelination, and time for recovery to full myelination in Down syndrome, more cases require examination and assessment. Magnetic resonance imaging has the advantage of serial assessment of myelination during brain maturation.

Brain↗
PubMed1986

Tumors and cysts.

"Congenital" tumors that cause hydrocephalus early in life are large masses and can easily be detected by ultrasound. CT is better for differentiating among the diverse types of mass lesions and is performed after screening by ultrasound. In our experience, ultrasound has proved successful for visualizing all of the intracranial cysts except those in the temporal fossa. Most patients with temporal fossa cysts, however, have other symptoms and signs, such as asymmetric head and seizures that lead to further investigation and correct diagnosis despite the failure to identify the temporal cysts by ultrasound. With newer and better ultrasound equipment, the detection of temporal fossa arachnoid cysts will be improved. We believe that neurosonography should be the initial tool for investigating infants and neonates who present with large heads or abnormally rapid increase in head size.

Brain↗
PubMed1986

Lumbo-peritoneal shunt malfunction. A new, simple and reliable CT sign.

Sixty CT scans in 31 patients who underwent lumboperitoneal shunting for communicating hydrocephalus showed that the size of the ventricles did not represent a good indicator of shunt malfunction. Instead, we discovered that the size of the basal cisterns around the brain stem enabled us to predict blockage earlier and more reliably. In a well functioning shunt, the basal cisterns are usually not visualized. In children with clinical shunt malfunction the cisterns dilate and become visible again. This occurs earlier and more frequently than ventricular enlargement. We therefore conclude that visible cisterns in association with persistent symptoms of malfunction are more reliable predictors of a true blockage that requires shunt revision than serial studies of ventricular size.

Brain↗
PubMed1984

The "empty sella" in childhood.

The "empty sella" (ES), a common entity in adults, is so named because a cerebrospinal fluid-filled arachnoid hernia fills the pituitary fossa and compresses the pituitary gland, creating the illusion of an "empty" sella. We report our experience of ES in childhood. Our four cases represent associations with ES that have not been previously described in childhood: case 1 was associated with central precocious puberty; case 2 with secondary ES resulting from shrinkage of a prolactinoma during bromocriptine therapy; case 3 with pseudotumor cerebri; and case 4 with no significant pathology. Together, they account for approximately 1 percent of cases of radiographically enlarged sella tursica investigated here. This brings the number of cases of ES reported in children to 27. Review of these 27 cases reveals seven with local skull dysplasia and/or a familial inheritance. The remainder lacked clinical homogeneity or similarity to the common adult variety of ES. Children with ES did not exhibit the higher female preponderance reported in adults with ES. They showed a higher frequency of secondary cases (4/27), and of associated endocrine (10/15) and visual (8/17) abnormalities than is seen in adults with the "empty sella."

Adolescent↗
PubMedDate not supplied

Radiologic characteristics of primitive neuroectodermal tumors in children.

Radiographic findings are reviewed in 31 children with primitive neural ectodermal tumors seen at the Hospital for Sick Children from 1962 through 1983. Seventeen children were initially evaluated with computed tomography (CT). Ten of these had both CT studies and angiography. The tumors were large, irregular, typically iso- to hyperdense, and showed dense, heterogeneous contrast enhancement. Cysts were present in 65% and calcifications in 71% of cases. The angiographic findings were nonspecific, ranging from avascular to markedly vascular. Although these tumors were usually found in the cerebral hemisphere, particularly the frontal lobes, two cases are included of tumors arising elsewhere: one in the pineal and one in the suprasellar region. Epidemiologic data are reviewed.

Adolescent↗