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Biomedical subjects

N J Newman

Publications and source records attributed to N J Newman.

At least 19 recordsLinked to original sources

Traumatic homonymous hemianopia.

OBJECTIVE: To describe the characteristics of patients with homonymous hemianopia from traumatic brain injury (TBI) seen in our unit between 1989 and 2004. METHODS: Only patients with a history of TBI, who had detailed clinical information and results of neuroimaging, were included in our study. Demographic characteristics, clinical features, types of visual field defects, location of lesion and evolution of visual field defects were recorded. RESULTS: Of the 880 patients with homonymous hemianopia seen in our unit, 103 patients (112 with homonymous hemianopia) had TBI (74 men and 29 women, mean age 30.7 (SD 15.3) years). Median time from injury to initial visual field testing was 5 (range 0.5-360) months. In all, 64 (57.1%) patients sustained injuries that were motor vehicle-related; 19 (17%) violence-related; 17 (15.2%) due to falls; and 12 (10.7%) because of other blunt head trauma. Visual field defects included complete homonymous hemianopia in 44 (39.3%) patients and incomplete homonymous hemianopia in 68 (60.7%) patients. The lesion was occipital in 14 (12.5%) patients, associated with optic radiation in 26 (23.2%) and the optic tract in 12 (10.7%), and multiple in 60 (53.6%). CONCLUSION: Most cases of homonymous hemianopia from TBI were motor vehicle-related. Patients were younger, more often male, and had multiple brain lesions more often than patients with homonymous hemianopia from causes other than TBI. A median delay of 5 months was observed before the documentation of the homonymous hemianopia, which may have a major effect on the success of rehabilitation and driving training in these young patients.

Accidents, Traffic↗

Natural history of homonymous hemianopia.

OBJECTIVE: To describe the characteristics of spontaneous recovery of homonymous hemianopia (HH). METHODS: The authors reviewed medical records of all patients with HH confirmed by formal visual field testing and seen in follow-up in their service between 1989 and 2004. Clinical characteristics, causes, neuroradiologic definition of lesion location, final outcome, and evolution of the visual field defects were recorded. The associations among final visual field defect outcome, time from injury, and clinical features were analyzed. RESULTS: A total of 254 patients with 263 HH were included in this study. Spontaneous visual field defect recovery was observed in 101 HH (38.4%). The likelihood of spontaneous recovery decreased with increasing time from injury to initial visual field testing (p = 0.0003). The probability of improvement was related to the time since injury (p = 0.0003) with a 50 to 60% chance of improvement for cases tested within 1 month after injury that decreased to about 20% for cases tested at 6 months after surgery. No other factor was found to correlate with the final outcome of the visual field defects. Improvement after 6 months from injury was mild and usually related to improvement of the underlying disease. CONCLUSION: Spontaneous improvement of homonymous hemianopia is seen in at least 50% of patients first seen within 1 month of injury. In most cases, the improvement occurs within the first 3 months from injury. Spontaneous improvement after 6 months postinjury should be interpreted with caution as it is most likely related to improvement of the underlying disease or to improvement in the patient's ability to perform visual field testing reliably.

Adolescent↗

Homonymous hemianopias: clinical-anatomic correlations in 904 cases.

OBJECTIVE: To describe the clinical characteristics and clinical-anatomic correlations of homonymous hemianopia (HH). BACKGROUND: Homonymous hemianopia impairs visual function and frequently precludes driving. Most knowledge of HH is based on relatively few cases with clinical-anatomic correlations. METHODS: The authors reviewed medical records of all patients with HH seen in their service between 1989 and 2004. Demographic characteristics, characteristics of visual field defects, causes of visual field defects, neuroradiologic definition of lesion location, and associated neurologic deficits were recorded. RESULTS: A total of 904 HH were found in 852 patients. A total of 340 HH (37.6%) were complete and 564 HH (62.4%) were incomplete. Homonymous quadrantanopia (264 HH, 29%) was the most common type of incomplete HH, followed by homonymous scotomatous defects (116 HH, 13.5%), partial HH (114 HH, 13%), and HH with macular sparing (66 HH, 7%). A total of 407 HH (45.0%) were isolated. Causes of HH included stroke (629 HH, 69.6%), trauma (123, 13.6%), tumor (102, 11.3%), brain surgery (22, 2.4%), demyelination (13, 1.4%), other rare causes (13, 1.4%), and unknown etiology (2, 0.2%). The lesions were most commonly located in the occipital lobes (45%) and the optic radiations (32.2%). Every type of HH, except for unilateral loss of temporal crescent and homonymous sectoranopia, was found in all lesion locations along the retrochiasmal visual pathways. CONCLUSION: Homonymous hemianopia is usually secondary to stroke, head trauma, and tumors. Although the characteristics of visual field defects can be helpful in lesion location, specific visual field defects do not always indicate specific brain locations.

Adolescent↗

Progressive outer retinal necrosis presenting with isolated optic neuropathy.

Progressive outer retinal necrosis is a necrotizing herpetic retinopathy usually seen in immunocompromised patients. The authors describe two patients with this disease who initially had findings suggestive of an optic neuropathy. Vision declined after treatment with methylprednisolone, after which fundus examination became consistent with progressive outer retinal necrosis. These cases underscore the importance of careful examination of the retinal periphery before management of any presumed optic neuropathy with steroids.

AIDS-Related Opportunistic Infections↗

Ophthalmologic features of Parkinson's disease.

Patients with Parkinson's disease (PD) commonly complain of impaired visual function and difficulty reading, despite normal visual acuity. Although previous studies have evaluated contrast sensitivity, color vision, visuospatial processing, visual hallucinations, and ocular movements, none has systematically evaluated the ocular complaints and ocular findings of PD patients. Thirty patients with early untreated PD and 31 control subjects without neurologic or known ocular diseases were ophthalmologically evaluated for the frequency of visual complaints, dry eyes, blepharitis, visual hallucinations, reduced blink rate, blepharospasm, and convergence insufficiency. Ocular complaints suggesting ocular surface irritation, altered tear film, visual hallucinations, blepharospasm, decreased blink rate, and decreased convergence amplitudes were more common in PD patients than in control subjects. These findings likely account for many of the visual difficulties commonly encountered by PD patients. These ocular abnormalities frequently respond to treatment.

Adult↗

Hereditary optic neuropathies.

AIMS: To provide a clinical update on the hereditary optic neuropathies. METHODS: Review of the literature. RESULTS: The hereditary optic neuropathies comprise a group of disorders in which the cause of optic nerve dysfunction appears to be hereditable, based on familial expression or genetic analysis. In some hereditary optic neuropathies, optic nerve dysfunction is typically the only manifestation of the disease. In others, various neurologic and systemic abnormalities are regularly observed. CONCLUSION: The most common hereditary optic neuropathies are autosomal dominant optic atrophy (Kjer's disease) and maternally inherited Leber's hereditary optic neuropathy. We review the clinical phenotypes of these and other inherited disorders with optic nerve involvement.

Dysautonomia, Familial↗

The use of contact lenses to treat visually symptomatic congenital nystagmus.

It has been suggested that contact lens wear improves the visual function of patients with visual loss from congenital nystagmus. In this study, four patients with congenital nystagmus had two evaluations separated by at least one week (one with spectacles, one with contact lenses) including visual acuity, contrast sensitivity, oscillopsia scale, quality of life questionnaire (NEI VFQ-25), and eye movement recording with an infrared tracking system. All patients subjectively preferred contact lenses to spectacles. Their contrast sensitivity and VFQ-25 scores were improved with contact lenses compared with spectacles alone. Several parameters of nystagmus showed no change in two patients, worsening in one patient and improvement in one patient. This suggests that much of the clinical improvement observed in our patients may result from a better optical correction of their refractive error with contact lenses than with spectacles, rather than from a true damping effect of the nystagmus by contact lenses.

Adolescent↗

Diffusion weighted imaging in radiation necrosis.

This case report suggests that magnetic resonance imaging with diffusion weighted imaging may help distinguish between tumour recurrence and radiation induced necrosis in patients previously treated for a brain tumour.

Adult↗

Clinical, genetic, and biochemical characterization of a Leber hereditary optic neuropathy family containing both the 11778 and 14484 primary mutations.

Four mitochondrial DNA (mtDNA) mutations at nps 3460, 11778, 14484, and 14459 account for roughly 90% of cases of Leber hereditary optic neuropathy (LHON) and are designated as "primary" LHON mutations since they act as major predisposition factors for LHON. Although each primary mutation can arise independently on different mtDNA backgrounds during human evolution, they characteristically do not co-occur in LHON patients. We report here a family with the simultaneous occurrence of the 11778A and 14484C mutations. Neuro-ophthalmological examination of the proband, a nine-year-old Caucasian female, revealed the bilateral optic atrophy, central scotomas, and reduced visual acuity typical of LHON. Her mother had normal appearing optic discs and is today visually asymptomatic. Analysis of the proband blood mtDNA revealed that she harbored both the 11778A (heteroplasmic, 94% mutant) and the 14484C (homoplasmic mutant) mutation. This genotype was maintained in proband lymphoblasts and transmitochondrial cybrids. The mother also had both mutations, with the 14484C mutation homoplasmic in all cell types examined. However, only 31% of her blood mtDNAs carried the 11778 mutation, which segregated to essentially 100% wild-type in lymphoblast and cybrid mtDNA. Complex I-linked respiration and specific enzyme activity were consistently lowest in proband lymphoblast and cybrid mitochondria compared to those from the mother, 11778A patients, 14484C patients, or controls, thus demonstrating both a deleterious synergistic interaction between the 11778A and 14484C mutations and the magnitude of 11778A-associated complex I dysfunction. Remarkably, spontaneous vision recovery occurred in the proband, highlighting the complexities encountered when associating mtDNA genotype and complex I function with LHON expression.

Cell Line↗

Novel mtDNA mutations and oxidative phosphorylation dysfunction in Russian LHON families.

Leber's hereditary optic neuropathy (LHON) is characterized by maternally transmitted, bilateral, central vision loss in young adults. It is caused by mutations in the mitochondrial DNA (mtDNA) encoded genes that contribute polypeptides to NADH dehydrogenase or complex I. Four mtDNA variants, the nucleotide pair (np) 3460A, 11778A, 14484C, and 14459A mutations, are known as "primary" LHON mutations and are found in most, but not all, of the LHON families reported to date. Here, we report the extensive genetic and biochemical analysis of five Russian families from the Novosibirsk region of Siberia manifesting maternally transmitted optic atrophy consistent with LHON. Three of the five families harbor known LHON primary mutations. Complete sequence analysis of proband mtDNA in the other two families has revealed novel complex I mutations at nps 3635A and 4640C, respectively. These mutations are homoplasmic and have not been reported in the literature. Biochemical analysis of complex I in patient lymphoblasts and transmitochondrial cybrids demonstrated a respiration defect with complex-I-linked substrates, although the specific activity of complex I was not reduced. Overall, our data suggests that the spectrum of mtDNA mutations associated with LHON in Russia is similar to that in Europe and North America and that the np 3635A and 4640C mutations may be additional mtDNA complex I mutations contributing to LHON expression.

Adolescent↗

Rhino-orbital mucormycosis in a patient with acquired immunodeficiency syndrome (AIDS) and neutropenia.

PURPOSE: To present a case of rhino-orbital mucormycosis in a patient with AIDS and neutropenia managed without exenteration. METHODS: Case report. RESULTS: A 60-year-old African-American man with AIDS developed neutropenia that was probably secondary to antiretroviral therapy. He developed right rhino-orbital mucormycosis and was treated with right partial ethmoidectomy with debridement and liposomal amphotericin B. The infection was cured without need for orbital exenteration, although visual acuity in his right eye ultimately was no light perception. CONCLUSION: Rhino-orbital mucormycosis is uncommon in patients with AIDS. When rhino-orbital mucormycosis occurs, patients require a careful search for an underlying metabolic derangement such as neutropenia. Treatment should be aggressive, but these patients may not require orbital exenteration.

Acquired Immunodeficiency Syndrome↗

Clinical spectrum of posterior ischemic optic neuropathy.

PURPOSE: To describe the systemic and visual characteristics and prognosis in patients with posterior ischemic optic neuropathy (PION). DESIGN: Observational case series. METHODS: Retrospective chart review in a multicenter setting. Seventy-two patients (98 eyes) with a clinical diagnosis of PION. Co-morbid systemic diseases and visual function were recorded at both initial presentation and after mean visual follow-up of 4.1 years and systemic follow-up of 5.4 years. RESULTS: PION occurred in three main settings: in the perioperative period following a variety of surgical procedures (28 patients), associated with giant cell (temporal) arteritis (6 patients), and associated with nonarteritic systemic vascular disease (38 patients). Patients with perioperative and arteritic PION were more likely to have severe, bilateral visual loss that did not improve. Among eyes with nonarteritic PION, 34% experienced improvement in vision, 28% remained stable, and 38% worsened. Among patients with nonarteritic PION, carotid artery disease and a history of stroke (with or without carotid artery disease) were both associated with a statistically significant increased risk of poor final visual outcome. CONCLUSIONS: There are three distinct subtypes of PION: perioperative, arteritic, and nonarteritic. Patients with PION that is unassociated with surgery should undergo an evaluation for systemic vascular diseases, including giant cell arteritis, that may or may not be apparent at the time of vision loss. The visual prognosis for patients with perioperative or arteritic PION is poor, whereas that for nonarteritic PION is similar to that for patients with nonarteritic AION.

Adolescent↗