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Biomedical subjects

Nancy J Newman

Publications and source records attributed to Nancy J Newman.

At least 37 records · Page 2Linked to original sources
PubMed2005

Simultaneous bilateral retinal artery occlusions associated with a mitral valve mass.

A 52-year-old woman with simultaneous bilateral retinal artery occlusions and normal trans-thoracic echocardiography was found to have a mitral valve lesion on trans-esophageal echocardiography. Bilateral retinal artery occlusions suggest a source of emboli at the level of the heart or aortic arch. Such cases should be evaluated not merely by trans-thoracic echocardiography, but by trans-esophageal echocardiography, which better visualizes the aortic arch and left heart cavities.

Calcinosis↗
PubMed2005

Eliminating the Ant1 isoform produces a mouse with CPEO pathology but normal ocular motility.

PURPOSE: The adenine nucleotide transporter 1 gene (ANT1) encodes an inner mitochondrial membrane protein that transports ATP into the cell. Mutations within ANT1 produce a syndrome of chronic progressive external ophthalmoplegia (CPEO) in humans. Ant1 knockout (Ant1-/-) mice develop cardiomyopathy and mitochondrial myopathy of limb muscles. Because the extraocular muscles (EOM) are preferentially affected in human CPEO, the objective of this study was to determine whether Ant1-/- mice also exhibit an EOM mitochondrial myopathy. METHODS: ANT isoform expression of isolated EOMs, EOM morphology and mitochondrial content, mitochondrial structure and function, ocular motility in intact mice, and contractile performance in isolated muscle preparations were examined. RESULTS: Ant1-/- EOMs had the typical appearance of mitochondrial myopathy, including increase in mitochondrial size, number, and oxidative phosphorylation (OXPHOS) staining. However, there were no measurable ocular motor abnormalities in intact Ant1-/- mice, and their isolated EOMs did not show evidence of increased fatigability. EOMs of wild-type mice exhibited higher levels of Ant2 mRNA compared with hindlimb muscle, which may compensate for the Ant1 loss in mutant mouse EOMs and account for the normal EOM function. CONCLUSIONS: The Ant1-/- mice provide a model in which to study CPEO pathology and compensatory mechanisms.

Adenine Nucleotide Translocator 1↗
PubMed2005

Optic nerve glioma and optic neuritis mimicking one another: case report.

OBJECTIVE AND IMPORTANCE: The clinical and radiographic presentations of optic nerve gliomas and optic neuritis are for the most part distinct and their diagnoses straightforward. We present two cases illustrating the occasional difficulty one can encounter in distinguishing neoplastic from inflammatory optic neuropathies. CLINICAL PRESENTATION: Patient 1 is a 17-year-old girl who presented with acute onset of pain and rapidly progressive visual loss in the right eye. Patient 2 is a 38-year-old man who presented with painless progressive visual loss in the left eye. INTERVENTION: Patient 1 was initially diagnosed with idiopathic retrobulbar optic neuritis. Interval increase of the optic nerve on magnetic resonance imaging prompted a biopsy of the optic nerve, which revealed a pilocytic astrocytoma. Patient 2 was found to have left optic nerve enhancement most consistent with an optic nerve glioma. Before a biopsy, the patient spontaneously improved without treatment, indicating an inflammatory process. CONCLUSION: Differentiating between optic nerve neoplasm and inflammation may be difficult. On occasion, the classic clinical finding of pain with eye movement and the radiographic finding of enlargement and enhancement of the optic nerve may be misleading. Open biopsy of the optic nerve is indicated only after a completely negative metabolic, infectious, and inflammatory workup; interval increase of the optic nerve on magnetic resonance imaging; and failure of the patient to recover vision.

Adolescent↗
PubMed2005

Ischemic optic neuropathy following spine surgery.

Perioperative visual loss (POVL) is a devastating injury that has been reported infrequently after nonocular surgery. The most common cause of POVL is ischemic optic neuropathy (ION). Increasing numbers of cases of ION are being reported after spine surgery, but the etiology of postoperative ION remains poorly understood. After a MEDLINE search of the literature, we reviewed published case reports of ION, specifically those reported after spine surgery performed with the patient in the prone position. Most of the cases involved posterior ION (PION, n = 17), and the remainder anterior (AION, n = 5). Most patients had no or few preoperative vascular disease risk factors. All except one PION and 2 of 5 AION cases reported symptom onset within the first 24 hours after surgery. Visual loss was frequently bilateral (40% of AION, 47% of PION cases). Mean operative time exceeded 450 minutes. The lowest average intraoperative mean arterial blood pressure was 64 mm Hg and the mean lowest intraoperative hematocrit was 27%. The average blood loss was 1.7 L for AION and 5 L for PION patients. PION patients received an average of 8 L of crystalloid solution and 2.2 L of colloid intraoperatively. This compilation of case reports suggests that a combination of prolonged surgery in the prone position, decreased ocular perfusion pressure, blood loss and anemia/hemodilution, and infusion of large quantities of intravenous fluids are some of the potential factors involved in the etiology of postoperative ION. However, levels of blood pressure and anemia intraoperatively were frequently at levels considered acceptable in anesthesia practice. The etiology of postoperative ION remains incompletely understood. Potential strategies to avoid this complication are discussed.

Adolescent↗
PubMed2004

Ischemic optic neuropathies.

PURPOSE OF REVIEW: To review recent clinical data on ischemic optic neuropathies, which are some of the most frequently encountered optic neuropathies. These disorders include nonarteritic anterior ischemic optic neuropathy, arteritic anterior ischemic optic neuropathy, and posterior ischemic optic neuropathy. RECENT FINDINGS: Recent studies have facilitated our understanding of the natural history of visual loss, recovery, and recurrence in these disorders. Additionally, the value of various diagnostic techniques and treatment options, particularly for arteritic anterior ischemic neuropathy, has been clarified. SUMMARY: Application of the studies described in this paper should allow the clinician to more accurately diagnose ischemic optic neuropathies and counsel the patient with regard to appropriate management, prognosis for visual recovery and future risk of recurrence.

Adrenal Cortex Hormones↗
PubMed2004

Diagnosis and management of MELAS.

Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is the most common maternally inherited mitochondrial disease. An A-->G mutation in the transfer RNA(Leu(UUR)) gene at position 3243 of the mitochondrial DNA accounts for most MELAS cases. The transient nature of the stroke-like episodes is reflected in abnormalities on neuroimaging. The cardinal laboratory abnormalities include elevated serum lactate during the acute episodes and respiratory enzyme defects in skeletal muscle. Muscle biopsy also helps confirm the diagnosis by identifying abnormal proliferation of mitochondria. Although current treatment options for MELAS are largely supportive, several therapeutic approaches have been attempted with limited success. Genetic counseling is an important component of patient management in MELAS. Newer reproductive technologies hold promise for reducing the recurrence of MELAS in subsequent generations. Advances in research into gene therapy offer hope of treatment for the future.

Age of Onset↗
PubMed2003

Hypertensive brainstem encephalopathy: clinical and radiographic features.

Reversible posterior leukoencephalopathy syndrome associated with hypertension rarely presents with predominant involvement of the brainstem and relative sparing of the supratentorial regions. We describe the clinical and neuroimaging features of three patients with reversible hypertensive brainstem encephalopathy. Headache and confusion in the setting of severe hypertension, with a relative paucity of brainstem signs and symptoms, despite extensive neuroimaging abnormalities in the brainstem support the diagnosis. The clinical findings and neuroimaging abnormalities resolve with treatment of the hypertension, further distinguishing this syndrome from brainstem infarction.

Adult↗
PubMed2003

Anemia and papilledema.

PURPOSE: To elucidate the relationship between anemia and raised intracranial pressure (ICP). DESIGN: Interventional case series. METHODS: Retrospective case series and review of the literature. Only patients with documented papilledema, neuroimaging ruling out a space-occupying lesion, and anemia were included. RESULTS: Five women with confirmed idiopathic intracranial hypertension (IIH) (normal brain magnetic resonance imaging, normal cerebrospinal fluid, elevated intracranial pressure), and one man with presumed IIH (normal head computed tomography [CT], no lumbar puncture) were evaluated. All had bilateral papilledema associated with peripapillary hemorrhages. Two had retinal cotton-wool spots (CWS), and two had preretinal hemorrhages. All had severe iron deficiency anemia, which was discovered at the time of their ocular complaints in five of them. Their symptoms and signs improved dramatically after treatment of the anemia. We found 30 well-documented cases in the English and French literature. Among those, 13 were excluded from our analyses (11 had confounding disorders, and two had cerebral venous thrombosis). In the remaining 17 cases, isolated raised ICP associated with anemia was the most likely diagnosis, although in none of these cases was cerebral venous thrombosis excluded. CONCLUSIONS: Anemia may play a role in the occurrence of raised ICP and papilledema. Although only a few cases in the literature support this association, it may be more common than previously thought. Because most patients are not known to be anemic when papilledema is discovered, we suggest that a complete blood count be obtained in patients with IIH, especially in the absence of known associated factors such as obesity or medications or when treatment aimed at lowering ICP fails to improve the patient's symptoms. The underlying mechanisms remain unknown, but cerebral venous thrombosis should be carefully excluded.

Adult↗
PubMed2003

Magnetic resonance imaging abnormalities in cat-scratch disease encephalopathy.

A 23-year-old woman who presented with a branch retinal artery occlusion followed by encephalopathy showed, by brain magnetic resonance imaging, a nonenhancing lesion in the right parietal gray matter with normal diffusion-weighted imaging. Of 64 reported cases of cat-scratch encephalopathy with documented neuroimaging findings, only 12 (18.8%) have had abnormal imaging findings. The abnormalities have included cerebral white matter lesions, basal ganglia and thalamic lesions, and multifocal lesions in immunocompromised patients, but no gray matter lesions similar to those in this patient. The variety of neuroimaging findings supports multiple pathophysiologic mechanisms of central nervous system involvement in this disorder.

Adult↗
PubMed2003

Leptomeningeal enhancement and venous abnormalities in granulomatous angiitis of the central nervous system.

A 68-year-old woman with a relatively acute onset of right homonymous hemianopia, Gerstmann syndrome, and global cognitive failure was found to have a lymphocytic pleocytosis and elevated protein on spinal fluid examination and displayed marked meningeal enhancement on magnetic resonance imaging and dilated cortical venules on cerebral angiography. Brain and meningeal biopsy disclosed a necrotizing granulomatous inflammation of small and medium-sized subarachnoid vessels. The brain parenchyma was normal. The angiographic presence of venous abnormalities, the lack of observable angiographic arterial involvement, and the lack of parenchymal pathology are distinctly unusual in granulomatous angiitis of the central nervous system. This case, therefore, extends the pathologic and imaging spectrum of this disorder.

Aged↗
PubMed2003

Arachnoid cyst of the optic nerve: report of two cases and review of the literature.

PURPOSE: To describe two patients with arachnoid cysts of the optic nerve mimicking optic nerve/orbital neoplasms. METHODS: The histories, ophthalmic examinations, and pathologic findings of two patients with arachnoid cysts of the optic nerves were reviewed and compared with previously reported cases. RESULTS: One patient had progressive proptosis and the other had decreased vision with visual field changes. Pathologic examination of optic nerve sheath biopsies showed redundant proliferations of meningothelial cells with associated thickened dura. CONCLUSIONS: Arachnoid cysts of the optic nerve are benign, slowly progressive conditions that may result in proptosis and visual field changes. The clinicopathologic features of arachnoid cyst should be differentiated from optic nerve sheath meningioma and other conditions.

Adult↗
PubMed2003

Neuro-ophthalmology of mitochondrial diseases.

PURPOSE OF REVIEW: To review recent data on mitochondrial diseases with emphasis on their neuro-ophthalmic manifestations. RECENT FINDINGS: Numerous studies have associated mitochondrial diseases with neuro-ophthalmic manifestations. Although there has been an explosion of studies on the genetics of mitochondrial diseases over the past few years, pathogenesis is only partly understood and therapy remains very limited. Over the past year, new mutations in Leber's hereditary optic neuropathy have been reported, and at least three genes associated with autosomal dominant chronic progressive external ophthalmoplegia have been described. These findings allow a better definition of the specific genetic mutations and gene products as well as pathophysiology of Leber's hereditary optic neuropathy and chronic progressive external ophthalmoplegia. The current development of animal models allows a better understanding of the pathophysiology of human mitochondrial diseases. SUMMARY: The afferent and efferent visual pathways within the central nervous system are frequently involved in mitochondrial diseases. Neuro-ophthalmic signs figure prominently and may be the presenting or even sole manifestation of these disorders. The four most common neuro-ophthalmic abnormalities seen in mitochondrial disorders are bilateral optic neuropathy, ophthalmoplegia with ptosis, pigmentary retinopathy, and retrochiasmal visual loss.

DNA Mutational Analysis↗