The human premotor oculomotor brainstem system – can it help to understand oculomotor symptoms in Huntington's disease?

Recent progress in oculomotor research has enabled new insights into the functional neuroanatomy of the human premotor oculomotor brainstem network. In the present review, we provide an overview of its functional neuroanatomy and summarize the broad range of oculomotor dysfunctions that may occur in Huntington's disease (HD) patients. Although some of these oculomotor symptoms point to an involvement of the premotor oculomotor brainstem network in HD, no systematic analysis of this functional system has yet been performed in brains of HD patients. Therefore, its exact contribution to oculomotor symptoms in HD remains unclear. A possible strategy to clarify this issue is the use of unconventional 100-µm-thick serial tissue sections stained for Nissl substance and lipofuscin pigment (Nissl-pigment stain according to Braak). This technique makes it possible to identify the known nuclei of the premotor oculomotor brainstem network and to study their possible involvement in the neurodegenerative process. Studies applying this morphological approach and using the current knowledge regarding the functional neuroanatomy of this human premotor oculomotor brainstem network will help to elucidate the anatomical basis of the large spectrum of oculomotor dysfunctions that are observed in HD patients. This knowledge may aid clinicians in the diagnosis and monitoring of the disease.     

Xeromammographic automatic exposure termination

A method of automatic exposure termination (AET) for xeromammography has been devised, significantly reducing the rate of repeat exposures due to poor choice of manual exposure factors. AET images are of good quality and are reliably produced. The concept of AET is based on the existence of an optimal transmitted exposure to the selenium plate, which is easily determined experimentally. In routine clinical xeromammography, a repeat rate of 20% was eliminated by the use of AET.     

The use of in vivo lumbar discography to assess the clinical significance of the position of the intercrestal line

An investigation of the clinical relevance of the location of the intercrestal line in relation to the pattern of disc degeneration in the lower lumbar spine is presented. An analysis of the discograms from 89 symptomatic patients has demonstrated a difference in the incidence of disc degeneration in the L4-5 and L5-S1 disc spaces dependent on the position of the intercrestal line. This difference supports the hypothesis that additional protection will be given to those L5-S1 discs with which high intercrestal lines are associated as compared to those associated with intercrestal lines lying lower down the spine. A corollary of this hypothesis is that for any individual there is an increased likelihood that the L4-5 disc space will undergo degeneration from the influence of normal mechanical stresses before the L5-S1 disc space if the intercrestal line lies comparatively high up the spine.     

Choroidal melanoma: A review of the experience of the Sydney Eye Hospital Professorial Unit 1979–1995

Purpose: This study examines 90 patients presenting with choroidal or ciliochoroidal melanoma to the Professorial Unit at the Sydney Eye Hospital. The indications for treatment, and the outcome for the eye and vision are presented together with an account of mortality and the incidence of metastases. Methods: A retrospective analysis of 90 choroidal melanoma patients managed by one surgeon over a 16-year period was undertaken. Initial findings, investigations performed, incidence of metastatic disease, treatment received and complication rates and mortality, where applicable, were recorded. Results: The group was followed for an average of 64 months (range, 5–172 months). Primary treatment was with either Iodine¹²⁵ (¹²⁵1) brachytherapy, local excision or enucleation. Radiation retinopathy was prominent in ¹²⁵1 cases resulting in poor visual acuity when the tumour resided in the posterior pole. Local excision even of large tumours was effective particularly if peripheral. Overall metastatic disease was seen in 11% with 5-year survival rates for the metastatic group being 10%. Prognosis after diagnosis of metastases was poor. Conclusions: Specific therapy for choroidal melanoma must relate to the size and location of the tumour at the time of diagnosis. Visual outcome relates directly to the proximity of the tumour to the optic nerve and fovea. Metastatic disease latency can be prolonged; therefore caution about prognosis is required long after therapy is given. The 5-year survival is encouraging with all forms of therapy. However, as the natural history of ocular melanoma is variable and not fully delineated it is important to monitor the effects of conservative therapy. Further long-term survival data is required to distinguish whether one form of treatment is advantageous over the others, although case-control studies are difficult for ethical and practical reasons. In this regard the Collaborative Ocular Melanoma Study (COMS) will provide further evidence for the safety and efficacy of conservative therapy with brachytherapy compared to enucleation.