PubMed HealthSearch

Biomedical subjects

K Meagher-Villemure

Publications and source records attributed to K Meagher-Villemure.

At least 19 recordsLinked to original sources

Lesionectomy of MRI detected lesions in children with epilepsy.

The results of complete excision of cerebral lesions detected by MRI in 18 children presenting with epilepsy were analyzed. There were 14 boys and 4 girls with a mean age of 9.2 years. The average age of onset of seizures was 6.8 years. The mean time from onset of seizures to surgery was 2.3 years. Often, CT scans suggested that the lesions were indolent. MRI was better in differentiating neoplastic from developmental lesions. Angiography was non-contributory in this series. Interictal EEGs showed epileptiform activity correlating with imaging studies in 54% of children. The lesion was completely surgically excised in all patients. This was confirmed by intra-operative ultrasound and postoperative imaging. Electrocorticography was performed prior to and after the resection, but residual spiking did not lead to further resection. The average postoperative follow-up was 5.7 years. Five patients had low grade astrocytomas, 4 had gangliogliomas, 1 a mixed astrocytoma-oligodendroglioma, 3 had cortical dysplasia, 2 infantile desmoplastic gangliogliomas, 2 hamartomata, and 1 cavernous angioma. Sixteen patients have been seizure-free since surgery. Only 2 have partial seizures. Thus, all patients benefited from the resection, with respect to seizure control. In those with temporal lobe lesions, improvement in IQ was seen postoperatively. Early consideration of surgery in patients with epilepsy and lesions demonstrated by MRI is suggested.

Adolescent

Fulminant hepatic failure associated with status epilepticus in children: three cases and a review of potential mechanisms.

Fulminant hepatic failure is a rare complication of status epilepticus. Although many of the anticonvulsants used to treat the seizures are known to have hepatotoxic properties, the exact mechanism leading to massive destruction of the liver following a prolonged seizure remains unclear. Three children are presented who developed fulminant hepatic failure following status epilepticus and subsequently died of multiple organ failure. The literature is reviewed with particular attention to the possible interaction between the anticonvulsants and the metabolic consequences of status epilepticus. We postulate that it is a combination of hypoxia and ischemia that occurs during a prolonged seizure with altered metabolism of free radicals secondary to the anticonvulsant drugs which leads to widespread hepatocyte membrane damage.

Anticonvulsants

Ganglioglioma presenting as a vascular lesion in a 10-year-old boy. Case report.

The authors present the case of a 10-year-old boy admitted for evaluation of a generalized seizure and a history of headaches. Computerized tomography (CT) and gadolinium-enhanced magnetic resonance (MR) imaging demonstrated a large nonhomogeneous contrast-enhancing mass of the left frontal lobe, with a large cystic component. Cerebral angiography revealed the lesion to be highly vascular and fed entirely by the internal carotid artery system. The patient underwent craniotomy and the lesion was completely removed. Neuropathological study revealed that the tumor was a ganglioglioma. On review of the literature, it was found that gangliogliomas often present in the second and third decade, are known to have cystic components, and are contrast-enhancing on CT and MR imaging; however, they are classically known to be avascular on angiography. This case of a markedly vascular ganglioglioma emphasizes that these tumors should be included in the differential diagnosis of vascular supratentorial lesions.

Brain Neoplasms

Dysplastic gangliocytoma (Lhermitte-Duclos disease): CT and MR imaging.

Dysplastic gangliocytoma (Lhermitte-Duclos disease) is a rare entity. Usually presenting as a posterior fossa mass, dysplastic gangliocytoma is not a true neoplasm but a hard-to-characterize lesion that may represent an abnormality of cell migration or a phacomatosis. Previous reports of CT findings are rare in the radiologic literature, and high-field (1.5 Tesla) MR images have never been described in the pediatric age group. We present a case of dysplastic gangliocytoma in a one-year-old boy with CT and MR findings.

Cerebellar Neoplasms

Brain dysgenesis and congenital intracerebral calcification associated with 3-hydroxyisobutyric aciduria.

Monozygotic male twins born to nonconsanguineous parents had dysmorphic facial features, microcephaly, migrational brain disorder, and congenital intracerebral calcification. They excreted excessive amounts of 3-hydroxyisobutyric acid, a metabolite of valine, and had evidence of impaired oxidative metabolism and metabolic acidosis. The level of 3-hydroxyisobutyrate in stored samples of midtrimester amniotic fluid was found to be high. The association of 3-hydroxyisobutyric aciduria with brain dysgenesis is a newly recognized mendelian disorder; its recurrence in a family at risk is potentially avoidable by prenatal diagnosis.

Amniotic Fluid

Aminopterin-like syndrome sine aminopterin associated with translocation involving chromosomes 5 and 10.

We studied a baby born with physical features suggestive of the aminopterin syndrome, but without exposure of the mother to aminopterin during pregnancy. G-banded chromosomes from peripheral blood lymphocytes had a normal 46,XX pattern. However, in 50 skin fibroblasts there was a normal female karyotype in 5 cells and 45 cells showed an apparently balanced reciprocal translocation involving the long arm of chromosome 5 (band q35) and the long arm of chromosome 10 (band q22). The relation of this mosaicism to the abnormal phenotype is unclear.

Abnormalities, Multiple

Encephalitis among Cree children in northern Quebec.

We report a neurological disease among Cree Indian children in a northern Quebec village. The disease manifests as severe mental retardation, cerebral atrophy with white matter changes and calcifications, and systemic immunological abnormalities. Eleven cases are known in five families. The familial incidence of cases and the high degree of parental consanguinity suggest a genetic contribution. We propose that this entity may be caused by an unusual viral infection in a genetically vulnerable host.

Adolescent

Leukoencephalopathy among native Indian infants in northern Quebec and Manitoba.

We report 14 cases of a severe familial leukoencephalopathy among native North American Indian infants in northern Quebec and Manitoba. Affected infants have hypotonia and mild motor delay, followed by seizures, hypotonia or spasticity, eye deviation, and abnormal posture during a febrile illness around 6 months of age. Death follows a rigid, vegetative state that manifests days to months after disease onset and is marked in some cases by prominent autonomic disturbances, blindness, and cessation of head growth. Symmetrical hemispheric white matter lucencies and diffuse hypomyelination of the cerebral hemispheres and brainstem are the radiological and pathological hallmarks. This disease differs from the known diseases of cerebral myelin. An autosomal recessive pattern of inheritance awaits statistical confirmation. The proposed cause is a delay in development or abnormal turnover of central nervous system myelin.

Brain

Intracerebral cavernous angiomas.

We studied 31 patients with histologically verified intracerebral cavernous angiomas. Twenty-two patients were symptomatic; nine were asymptomatic. All 22 symptomatic patients had seizures, three had intracranial hemorrhage, and one had signs of a space-occupying lesion. Twenty-seven lesions were located in the neocortex, three in the brainstem, and one in the cerebellum; all exhibited characteristic gross and microscopic features of cavernous angiomas. CT identified the location and extent of the lesion in 16 of 27 cases. Six of seven lesions demonstrated contrast enhancement, and ten of 27 scans harbored densities consistent with intracerebral calcium. Angiography was performed in 17 cases and was completely normal in eight. MRI revealed mixed signal intensity centrally with a ring of decreased signal intensity peripherally on T2-weighted images and was diagnostic in five cases. Surgical treatment offers an excellent prognosis for seizure control in patients with such lesions.

Adolescent

Subacute necrotizing encephalomyelopathy (Leigh disease): CT study.

Leigh disease, or subacute necrotizing encephalomyelopathy (SNE), is a familial, degenerative disorder characterized by lesions of the gray and white matter in the brain and spinal cord. Low attenuation in the putamina on computed tomography (CT) scans is considered to be characteristic of the disease. The authors used CT to study five patients, in three of whom the disease was confirmed histologically. In one of the patients with documented SNE, there was extensive gray matter lucency with normal basal ganglia. CT scans obtained in a second patient showed diffuse, diseased white matter with focal cortical extension and bilateral caudate involvement. In the other three cases, CT scans revealed the usual changes that occur in the basal ganglia. The appearance of SNE on CT scans thus reflects the variable and widespread distribution of the disease. The absence of radiologically detectable abnormalities in the basal ganglia should not deter one from the diagnosis of Leigh disease given in the appropriate clinical context.

Basal Ganglia

Primary malignant lymphoma of the central nervous system.

Between 1960 and 1983, 19 patients with primary malignant lymphoma of the central nervous system (CNS) were seen at McGill University Hospitals. The diagnosis was made at autopsy in 3 patients, and by biopsy in 16. Results of treatment were poor. All four patient who underwent surgery alone died within 2 months of diagnosis. Of 12 patients who underwent surgery and postoperative radiotherapy, 11 died between 2 and 56 months (median, 12 months) following diagnosis, and one is alive with disease at 47 months. Patterns of involvement at first recurrence and/or at autopsy were analyzed for 13 patients. Failure at the original site of involvement was unusual after treatment consisting of surgery and radiotherapy. In contrast, failure in the brain at sites other than those originally involved was common in spite of the use of whole brain irradiation. Local leptomeningeal involvement was seen in one patient whose diagnosis was made at autopsy, and cerebral spinal fluid seeding was seen in two additional patients, one within 1 month of diagnosis and one at relapse at 6 months after diagnosis. No patient developed disease outside the CNS. The limitations of current therapy for this disease are discussed, and certain suggestions made regarding the management of future patients with this diagnosis.

Acquired Immunodeficiency Syndrome

X-linked hydrocephalus.

Two French-Canadian families with seven cases of hydrocephalus in two generations are presented. The pattern of inheritance is consistent with an X-linked recessive transmission. The clinical and pathologic characteristics of this entity are reviewed. The anomaly of adducted thumbs was present in one patient and its cause is considered. The hypothesis of primary hydrocephalus and secondary compression of the aqueduct as the mechanism for aqueductal stenosis is discussed.

Brain

Cerebral amyloid angiopathy.

We studied 24 patients with autopsy-proven cerebral amyloid angiopathy. Eight patients were demented or had some other medical problem and died of pneumonia or systemic disease. Sixteen patients died of intracranial hemorrhage. Amyloid was found in cortical arteries and arterioles of all patients. CT showed diffuse atrophy in demented patients and intracerebral hematomas in the others. The location and size of the hematoma, with cortical and subarachnoid extension, help to differentiate amyloid angiopathy from other causes of intracranial hemorrhage in the elderly.

Age Factors

Lymphomatoid granulomatosis with isolated involvement of the brain.

A patient with biopsy-proven lymphomatoid granulomatosis of the brain as the sole manifestation of the disease is described. During 14 months of follow-up since surgical excision of the cerebral mass, no evidence of recurrent brain involvement or of extracranial lesions has been found. This case is unusual in the confinement of the disease to the central nervous system and in the favorable outcome following surgical treatment alone.

Brain Neoplasms

Optic nerve in globoid leukodystrophy (Krabbe's disease). Ultrastructural changes.

Globoid leukodystrophy (Krabbe's disease) was diagnosed in an infant in whom a progressive neurological disorder and optic atrophy developed. At autopsy, ultrastructural examination of the optic nerves and cerebral white matter revealed characteristic tubular inclusions in globoid-epithelioid cells. Thinning of the nerve fiber and ganglion cell layers of the retina appeared to be due to retrograde degeneration of the optic nerve related to the abnormal metabolism of myelin. We discuss the pathogenesis of the clinical and pathological ocular findings, with regard to the inherited absence of the enzyme galactocerebroside beta-galactosidase and the accumulation in the optic nerve and brain of its substrates, galactocerebroside and psychosine.

Brain