Palsies of the third, fourth, and sixth cranial nerves.

Diplopia is one of the most vexing problems to confront a physician. When diplopia is binocular, it commonly results from dysfunction of one or more of the ocular motor nerves. Ocular motor dysfunction may result from injury anywhere along the neuraxis, from the ocular motor nucleus to the myoneural junction. Identifying the location of the lesion is important for determining the etiology and prognosis of third-, fourth-, and sixth-nerve injuries. In this article, an anatomic approach is presented for the diagnosis and treatment of ocular motor nerve lesions. Emphasis is placed on the identification of associated neurologic and ophthalmologic findings that are critical for management of patients with acquired and congenital ocular motor palsies.

4.0 Tesla magnetic resonance imaging of brainstem lesions with ocular motility deficits.

The authors studied six patients with brainstem ocular motility deficits with 4.0 Tesla (T) magnetic resonance imaging to investigate whether a higher field strength would produce superior images compared with 1.5T. In four patients whose lesions were evident on 1.5T, the increased signal-to-noise achieved with 4.0T allowed for better resolution at 1-mm slice thickness than was achieved at the standard 5-mm slice thickness with 1.5T. In the two patients with unremarkable 1.5T scan results, 4.0T also failed to demonstrate a lesion. Therefore, 4.0T imaging has superior resolution to 1.5T imaging and can provide more detailed images of lesions identified by 1.5T.

New low-contrast vision charts: reliability and test characteristics in patients with multiple sclerosis.

The quantitative assessment of visual function in multiple sclerosis (MS) clinical trials has been limited to Snellen visual acuity. The purpose of this study was to examine the inter-rater reliability and test characteristics of a new visual outcome measure, the Low-Contrast Sloan Letter Charts, in patients with MS and visually-asymptomatic volunteers. Contrast letter acuity scores (letter scores) were measured at each of four contrast levels (100, 5, 1.25 and 0.6%) by two independent raters. Inter-rater agreement was described with the intraclass correlation coefficient (ICC) and comparison of mean scores. Excellent inter-rater agreement (ICC=0.86 - 0.95) was demonstrated at each contrast level among MS patients (n=100) and visually-asymptomatic volunteers (n=33). Average letter scores at the lowest contrast level (0.6%) were highly variable in the MS group, even among patients with visual acuities of 20/20 or better, and among those who required no assistance for ambulation. Low-Contrast Sloan Letter Chart testing is a highly reliable method of visual assessment, and provides information on an aspect of neurologic impairment in MS which is not captured by Snellen visual acuity or ambulation status. This new method demonstrates excellent potential as a visual function outcome measure for future MS clinical trials.

Evidence for preganglionic pupillary involvement in superficial siderosis.

A 36-year-old man presented with spinal myoclonus, ataxia, hearing loss, and unilateral pupillary dilation. MRI demonstrated hemosiderin deposition along the superficial surfaces of the brain, brainstem, cerebellum, and spine. The pupillary changes were localized to the preganglionic oculomotor nerve. In contrast to vasculopathic oculomotor nerve palsies, superficial siderosis may cause selective involvement of the superficially located pupillary fibers.

Variation in in-patient stroke management in ten centres in different countries: the INCLEN multicentre stroke collaboration.

BACKGROUND AND PURPOSE: Large within-country variations have been described in stroke management and there have been a few studies of between-country variation (in the USA and the UK). We designed a study to examine stroke management across a wide range of countries representing different stages of economic development. Large variations would suggest the need to explore methods of increasing the uptake of evidence-based stroke practice. METHODS: Members of the International Clinical Epidemiology Network (INCLEN) from 14 centres in ten countries agreed to review the records of the last 50 patients admitted to hospital with a clinical diagnosis of stroke. Information on demographic variables, the clinical diagnosis of stroke type, investigations performed and treatments given and the discharge destination of the patient were recorded and sent to the coordinating centre in Australia for analysis. RESULTS: There were statistically significant between-centre differences in the proportions of patients cared for by a neurologist, staying in hospital for at least ten days and having CT or MRI scans. Significant between-centre differences were also seen for treatment, for example, the use of aspirin in non-haemorrhagic stroke varied from 11 to 79%. The variation (for all interventions studied) was no longer statistically significant when examined within strata according to availability of facilities. CONCLUSIONS: The large variation between centres in the management of stroke is largely 'explained' by the availability of resources, even for interventions that do not depend on resource availability. It will be important to develop management guidelines that reflect evidence-based practice of relevance across a range of economic settings.

Acute sensorimotor polyneuropathy with tonic pupils and an abduction deficit: an unusual presentation of polyarteritis nodosa.

A tonic pupil may occur in isolation or as part of a systemic disorder. We report a patient who developed tonic pupils and an abduction deficit in the setting of polyarteritis nodosa. The combination of a tonic pupil and an abduction deficit should suggest the possibility of a vasculopathic disorder, because the ciliary ganglion and lateral rectus muscle are both supplied by the lateral muscular artery. Widespread small artery and arteriolar narrowing and occlusion are the hallmarks of polyarteritis nodosa. Unusual ischemic syndromes may occur, such as this rare combination of neuro-ophthalmic signs, by involvement of both the nutrient artery and its collaterals. We are unaware of other reports of neuropathic tonic pupils in association with polyarteritis nodosa.

Activated CD3- CD16+ natural killer cells express a subset of the lymphokine genes induced in activated alpha beta + and gamma delta + T cells.

In this study we analysed the potential of highly purified polyclonal TcR alpha beta+, TcR gamma delta + and CD3- NK cells, to produce lymphokines in response to mitogenic stimulation. RNA hybridizations were performed to detect with high sensitivity the induction of multiple lymphokine genes. Upon stimulation with lectin and phorbol ester TcR gamma delta + lymphocytes expressed the same set of lymphokine genes as the TcR alpha beta + lymphocytes expressed the same set of lymphokine genes as the TcR alpha beta + lymphocytes, which included IL-2, -3, -4, -5, GM-CSF, TNF alpha and beta, IFN gamma. In contrast, a more limited set of lymphokine genes (GM-CSF, TNF alpha and beta, IFN gamma) was induced in activated CD3- NK cells, thus indicating that this subpopulation of cells may display different regulatory functions, with respect to CD3+ T lymphocytes.

Projections from inferior temporal cortex to prefrontal cortex via the uncinate fascicle in rhesus monkeys.

In five rhesus monkeys (Macaca mulatta) we used anterograde and retrograde tracing techniques to investigate the projection from the inferior temporal cortex (area TE) to the prefrontal cortex as well as the course of the projecting fibers. The results showed that TE projects to both the inferior convexity and orbital surface of prefrontal cortex and that these projections course almost exclusively via the uncinate fascicle. Transection of the uncinate fascicle deprives the prefrontal cortex of virtually all input from TE, but leaves intact inputs from prestriate and parietal visual areas as well as the amygdala. Such transection also leaves intact many projections from TE to targets other than the prefrontal cortex, including the amygdala, ventral putamen, tail of the caudate nucleus, and pulvinar.