Intracranial fibromuscular dysplasia in a six-year-old child: a rare cause of childhood stroke.

Intracranial fibromuscular dysplasia is a nonatheromatous angiopathy that most commonly affects adult women and is rarely recognized in children. Symptoms include stroke and headache, although the vasculopathy may be asymptomatic. Diagnosis is based on angiographic appearance, commonly described as a "string of beads." The etiology of intracranial fibromuscular dysplasia is not known, although possible causes include genetic predisposition, trauma, and underlying connective tissue disease. Treatment of intracranial fibromuscular dysplasia is largely supportive once symptoms become manifest. We report a 6-year-old girl who presented to our center for further evaluation of a large left middle cerebral artery distribution infarction. The patient was previously healthy, without known risk factors for stroke. Initial symptoms consisted of a dense global aphasia and a right hemiparesis. On arrival, the patient's aphasia had improved but she continued to have significant deficits in both receptive and expressive language as well as residual right hemiparesis. Magnetic resonance imaging and conventional angiographic studies demonstrated characteristic beading of the distal portion of the left internal carotid artery, as well as the proximal middle cerebral artery. Laboratory evaluation, echocardiogram, and renal ultrasound were normal. The renal vasculature did not demonstrate evidence of intracranial fibromuscular dysplasia. In conclusion, intracranial fibromuscular dysplasia should be considered in the differential diagnosis of childhood stroke. When recognized, other sites of vascular involvement should be sought, and consideration of underlying disorders is important, as connective tissue disorders have been associated with a propensity to develop this vascular abnormality. Careful follow-up is warranted, due to possible progression of disease.

Melkersson-Rosenthal syndrome: new clinicopathologic findings in 4 cases.

OBJECTIVE: To define the clinicopathologic features of eyelid involvement in Melkersson-Rosenthal syndrome (MRS). METHODS: Four patients with eyelid edema consistent with MRS were evaluated clinically, including diagnostic imaging in 2 patients. Eyelid tissue from these patients was examined by light microscopy and immunohistochemistry. Polymerase chain reaction for herpes simplex virus was performed in 1 case. RESULTS: The 3 men and 1 woman ranged in age from 33 to 74 years. All patients had insidious, painless, nonpitting eyelid edema. Three patients had unilateral edema; one had bilateral, asymmetric involvement. Ipsilateral lip edema was present in 1 case. Computed tomography demonstrated periorbital heterogeneous thickening that corresponded to the microscopic finding of scattered granulomas. All 4 patients demonstrated epithelioid granulomas inside and adjacent to dilated lymphatic vessels. Polymerase chain reaction testing was negative for herpes simplex virus. CONCLUSIONS: Isolated eyelid swelling that mimics thyroid-associated ophthalmopathy may occur in MRS. Computed tomography may be useful in the diagnosis. Biopsy should be performed in all cases of unexplained nonpitting eyelid edema. In the eyelid, MRS is characterized histopathologically by a granulomatous lymphangitis, a finding that seems to be unique to this condition.

The clinical spectrum of schwannomas presenting with visual dysfunction: a clinicopathologic study of three cases.

Schwannomas (neurilemomas) are benign tumors that arise from Schwann cells in the peripheral nervous system. The most commonly involved nerves that cause neuro-ophthalmic manifestations are cranial nerves V and VIII. In this series of three women, schwannomas presented as intraconal masses that mimicked a cavernous hemangioma, a superior orbital mass transgressing the superior orbital fissure, and an expansive frontal lobe mass with clinical symptoms and signs of increased intracranial pressure. Although all three complained of visual blurring, none of our patients presented with Vth or VIIIth cranial nerve dysfunction. Histopathologic studies demonstrated well-circumscribed, encapsulated spindle-cell lesions with classic Antoni A and B patterns. Histopathologic examination is essential to confirm the diagnosis of a schwannoma that may be otherwise clinically confusing. Direct optic nerve compression, globe indentation with induced hyperopia, or increased intracranial pressure with optic nerve compromise may be responsible for visual symptoms. A multidisciplinary approach is often required because of the size and location of schwannomas.

Infarction in the territory of the anterior cerebral artery.

Infarction in the anterior cerebral artery (ACA) territory is an uncommon cause of stroke. The clinical findings of ACA infarctions are not fully characterized but include contralateral hemiparesis, urinary incontinence, transcortical aphasia, agraphia, apraxia, and executive dysfunction. We report a patient with a large right ACA infarction, who in addition to previously reported findings also had a complete hemiplegia, profound sensory neglect, and micrographia.

MR of extraocular muscles in chronic progressive external ophthalmoplegia.

PURPOSE: Our goal was to determine whether the extraocular muscles in patients with chronic progressive external ophthalmoplegia (CPEO) could be distinguished from those of age-matched control subjects by MR imaging. METHODS: Nine patients with CPEO and eight age-matched healthy control subjects were studied. The extraocular muscles of eight of the patients (16 eyes) and all the control subjects (16 eyes) were measured digitally. Images consisted of 1.5-mm contiguous sections acquired using a volume (three-dimensional) gradient-echo acquisition. In all, measurements were performed on 11 interpolated 1.0-mm coronal sections, five on each side of the muscle center. Only the medial, inferior, and lateral rectus muscles were evaluated. The superior rectus was omitted to avoid averaging problems with the superior ophthalmic vein and levator palpebrae muscle. The 11 sections were summed to obtain a volume measurement of the central portion of each muscle. RESULTS: The digitally measured extraocular muscles in the patients with CPEO had statistically significantly smaller volumes than those of the control subjects. The average muscle volumes for the patients with CPEO were 215 mm3 for the medial rectus, 202 mm3 for the inferior rectus, and 269 mm3 for the lateral rectus. The average extraocular muscle volumes for the control subjects were 366 mm3 for the medial rectus, 365 mm3 for the inferior rectus, and 425 mm3 for the lateral rectus. CONCLUSION: MR imaging can show small extraocular muscles in patients with CPEO, which may help to distinguish this disorder from other entities. Since denervated extraocular muscles do not readily atrophy, this MR sign would support a myogenic pathologic substrate for CPEO. Variation in the degree of extraocular muscle atrophy may simply reflect the length of time the mitochondrial defect and ophthalmoplegia have been present.

Isolated abducens nerve palsy: MR imaging findings.

The abducens nerve, the sixth cranial nerve, innervates the lateral rectus muscle of the eye and is responsible for lateral horizontal ocular movement. A wide variety of abnormalities, both primary to the nerve itself and secondarily involving the nerve, can paralyze the abducens nerve. MR imaging offers the best opportunity to detect the underlying abnormality causing abducens nerve palsy. In this pictorial essay, we illustrate the MR imaging features of numerous conditions that cause isolated abducens nerve palsy.

Structure and function of the human interleukin 2 receptor gene.

The gene encoding the human Interleukin 2 (IL-2) receptor consists of 8 exons spanning more than 25 kilobases on chromosome 10. Exons 2 and 4 were derived from a gene duplication event and unexpectedly also are homologous to the recognition domain of human complement factor B. Receptor gene transcription is initiated at two principal sites in normal activated T cells. Adult T cell leukemia cells infected with HTLV-I show activity at both of these sites, but also at a third transcription initiation site. Resting T cells do not contain detectable IL-2 receptor mRNA. Within 1 hour after stimulation with phytohemagglutinin (PHA), a large, presumably nuclear precursor RNA species is seen, which then gradually disappears. Mature IL-2 receptor mRNA forms appear within 8 hours after stimulation, reach peak levels between 8 and 24 hours, and then decline. Thus in PHA-activated lymphocytes the rise and fall in IL-2 receptor mRNA levels precede by more than 24 hours the peak and decline of IL-2 receptor protein expression occurring at the cell surface. Nuclease S1-protection assays indicate that IL-2 receptor mRNAs may differ in length due to the use of three different polyadenylylation signals. Further, these assays demonstrate the presence of transcripts that lack a 216-base segment within the protein-coding region and thus do not encode a functional IL-2 receptor. Nuclear transcription assays indicate that the increase in IL-2 receptor mRNA is reflected at the level of transcription. Thus, IL-2 receptor gene regulation controls IL-2 receptor expression at the cell surface and is intimately linked to the control of T-cell proliferation.

Development of enzymes of glycerol metabolism in human fetal liver.

The activities of three key enzymes of glycerol metabolism were measured in liver samples from 37 human fetuses ranging in gestational age from 18 weeks to term, from neonates (1-3 days) and from infants to 2 years. Glycerol kinase specific activity was constant throughout the period of fetal development examined, and was comparable to that measured in neonates and infants. However, the subcellular distribution of the activity changed markedly, being predominantly particulate in fetal samples and cytoplasmic in postnatal samples. The particulate activity had an elevated Km for glycerol. Cytoplasmic glycerol-3-phosphate dehydrogenase activity was very low in the fetal period, and then rose to adult levels during infancy. There were no kinetic differences between the fetal and postnatal activities. Mitochondrial glycerol-3-phosphate dehydrogenase activity rose somewhat after birth to near adult levels. The data indicate that glycerol can be metabolized by human fetal, neonatal and infant liver.

[Gonadotropin secretion following pernasal stimulation with synthetic gonadotropin releasing hormone (GnRH) and a highly effective GnRH-analog in healthy men and prepubertal boys]. / Gonadotropinsekretion nach pernasaler Stimulation mit synthetischem Gonadotropin-Releasing-Hormon (GnRH) und einem hochwirksamen GnRH-Analogon bei gesunden Männern und präpubertären Jungen).

Potent long acting analogs of GnRH are of great interest especially in view of pernasal (p.n.) treatmen of hypogonadism of hypothalamic origin and of cryptorchidism. To find the necessary p.n. dosage of such a substance, serum LH and FSH were measured in 6 normal adult human males after p.n. application of various doses of D Leu6-des-Gly10-GnRH ethylamide. 50 microgram of the GnRH analog were necessary to obtain increased serum gonadotropins over a period of at least 8 hours. By repeated p.n. application of 200 microgram of synthetic GnRH every 2 hours in 6 normal adult males a considerable increase of serum gonadotropins could be demonstrated as well. Pernasal application of 200 microgram GnRH repeated at an interval of 1 hour in 3 cryptorchid boys produced a distinct increase of the serum gonadotropins. The intraindividual comparison of 200 microgram GnRH and 20 microgram of the GnRH analog in one boy showed equivalent net increases of the gonadotropins. With the analog the gonadotropin increase lasted for about 6 hours.