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Show J. Clill. Neuro-ophtha/11lo/. 4: 275-284, 1984. Neuro-ophthalmology in the Recent European Literature Part III. Heredodegenerations, Stroke, Pain, and Diagnostic Techniques AVINOAM B. SAFRAN, M.D. In Part III, the final section in the series of articles reviewing neuro-ophthalmology in the recent European literature (January to June 1983), the following topics will be discussed: heredodegenerative disorders; retinal and cerebral stroke; pain; and diagnostic techniques. Heredodegenerative Disorders A survey of 97 cases of tuberous sclerosis, covering seizures, handicap, physical findings, and family aspects, was provided by Hunt.! T.he author emphasized the importance of dep!gmented spots as a diagnostic clue to tuberous sclerosis. Depigmented skin macules were the most common skin lesion, reported in 92 cases (95%). Occurrence of adenoma sebaceum w~s noted in 78 cases (80%), and shagreen patches In 47 (48%). Depigmented spots and shagreen patches were observed at birth, whereas the presence of adenoma sebaceum was not apparent at birth. Initially, adenoma sebaceum appeared as small red spots, which in some cases were transitory. Hunt stressed the importance of ~~e s.ystematic use of ultraviolet light for IdentIflcatIon of depigmented spots when examining f.amily members of affected children. Although It has been claimed that, in diseases with dominant inheritance pattern, the symptomatology of the affected subjects may vary according to the sex of the carrier parent, no such correlation could be established in this study. Profound handicap was mainly noted in those children who had an early onset of seizures. Of greatest concern for the parents were behavioral problems including. l~ck of communication, screaming, and hyperactIvity. They occurred in 58 children. Twenty parents said their major problem was the management of seizures. From Clinique d'ophtalmolgie, Hopital Cantonal Universitaire,. Geneva, Switzerland. December 1984 Patients with tuberous sclerosis can develop an unusual form of benign subependymal glioma characteristically located at the foramen of Monro. These patients should, therefore, be checked regularly for clinical evidence of i~creasing intracranial pressure. Because of resultIng hydrocephalus, these tumors are much small:r tha~ most other supratentorial gliomas when flrst diagnosed. Of eight patients with intracranial m~nifestations of tuberous sclerosis examined by Wmter," four also presented with glioma at the foramen of Monro. The value of computerized tomography in diagnosis of intracranial tumo~s versus tubers in patients with tuberous scleroSIS was discussed. Although both contain calcifications, glioma are differentiated from tubers by contrast enhancement in computerized tomography scanning. The importance of diagnosing bilateral obstruction of the foramen of Monro when the tumor arises bilaterally or when a large unilateral tumor encroaches on both foramina of Monro was also stressed by Winter. This condition necessitates bilateral shunting, a requirement reportedly easily overlooked in neurosurgical practice because of its rare occurrence. Ataxia-telangiectasia heterozygotes are predisposed to die from malignant neoplasm. This was suggested by Swift et al. 3 in 1976. The assertion was recently confirmed by Swift and Chase4 in a survey of causes of death in 16 deceased parents of affected patients. In addition to higher than usual rates of cancer death, a high incidence of ischemic heart disease was found. This was apparently the first study of causes of death in obligatory ataxia-telangiectasia heterozygotes, i.e., in parents of affected patients. Cancer in ataxia-telangiectasia could be treated with reduced radiotherapy and chemotherapy doses. This is an important fact when considering the elevated incidence of cancer and leukemia among these patients. Severe reaction to ionizing irradiation in patients with ataxia-telangiectasia has been known of for several years.s In addition, 275 Recent Literature: Part III Abadir and Hakami6 recently observed unusually high chemosensitivity in a case of ataxia-telangiectasia. Remarkably, in this patient, control of a nasopharyngeal undifferentiated lymphoma was achieved for 5 years with a therapy which is usually considered inadequate. A variety of patients showing atypical patterns of hereditary degenerative disorders were reported. Tuck and McLeod? observed four patients presenting with clinical features resembling Refsum's disease, but lacking both detectable biochemical abnormality and "onion bulb" formations on sural nerve biopsy. Occurrence of occasionally minimal peripheral nerve involvement in Refsum's disease was confirmed by Barbieri et al. 8 Salisachs9 reviewed his personal experience with Charcot-Marie-Tooth's and Refsum's diseases, and summarized new findings on the diseases. Variations in the motor and sensory neuropathy in these two conditions were discussed. Prominent bilateral papilloedema was observed by Beck10 in a patient with Hunter's syndrome (type II mucopolysaccharidosis). When he was a 23-year-old, the patient was first examined by an ophthalmologist for intermittent blurring of vision. Gross bilateral papilloedema was found, as well as pigmentary retinopathy. Lumbar puncture showed normal cerebrospinal fluid pressure, and cerebral computerized tomography scanning was unremarkable. Myelogram demonstrated an almost complete block at the C7-Tl level. Beck gave credit to McKusik11 for having previously described papilloedema in two patients with Hunter's syndrome. Bilateral fixed miosis was noted by Dick et al. 12 in four patients with hereditary spastic ataxia, aged between 17 and 44 years. Pupils were described as being 2 mm in diameter in two patients, and all four patients were unable to respond to light, accommodation, or reduction in ambient illumination. It was felt that the patients had congenital miosis, with absent or hypoplastic dilator muscle. Previous cases of congenital myosis were reviewed. The condition may be inherited, generally as an autosomal-dominant trait. It has been described in conjunction with arachnodactyly, congenital rubella and Lowe's oculocerebral syndrome. Retinal and Cerebral Stroke Monocular visual changes due to temporary reduction in blood flow to the ophthalmic arterial system may differ from those resulting from embolism. Ross Russell and Page13 described four patients with extensive occlusive disease of the extracranial arteries who complained of intermittent alteration in vision related to standing or mild exertion, or precipitated by heat (e.g., enter- 276 ing a hot room). In one patient, visual symptoms were reported to develop over minutes, and recovery of vision similarly took place gradually. Attacks consisted of a bright dazzling sensation, bright objects appeared lighter whereas dark objects became difficult to see. The overall effect was one of "overexposure." Another patient described the appearance as "a negative of a photograph." Sight becoming gradually patchy and fragmented was reported by two patients. A striking feature experienced by the patients was the occurrence of visual phenomena without any symptoms of cerebral ischemia. This led the authors to emphasize that the eye was a more sensitive index of hypotension than the brain. The risk of eventually developing contralateral occipital infarction following a unilateral occipital stroke was evaluated by Bogousslavsky et al. 14 Thirteen out of 58 patients studied (22.4%) presented with a contralateral occipital involvement, over a mean follow-up period of 39.6 months. The contralateral occipital stroke occurred after a delay of 2 days to 12 months with an average of 4.2 months. Absence of improvement of initial visual fields and border zone extension of the initial infarct towards the Sylvian area were significantly correlated with occurrence of contralateral involvement. During this follow-up period, there were only three delayed Sylvian strokes, versus 13 controlateral occipital infarction. The so-called atheromatous pseudo-occlusion is an extreme type of stenosing lesion which is easily misdiagnosed as complete occlusion with noninvasive evaluation and conventional angiography. However, in contrast with asymptomatic or oligosymptomatic complete occlusion of the internal carotid artery, pseudo-occlusion represents a major danger for the patient because, as emphasized by Ringelstein et al, 15 occurrence of infarction as a result of hemodynamic changes is frequent during the stage of subtotal stenosis. Therefore, pseudo-occlusion requires fast and appropriate therapeutic measures. Recent data indicate that pseudo-occlusion of the internal carotid artery is a frequent diagnostic trap. Recognition necessitates appropriate angiographic procedure. The serial imaging run must be prolonged to allow the dye to pass through the stenotic lesion during the radiological procedure. Furthermore, subtraction of the images is required. Ringelstein et al. reported nine subjects presenting with such pseudo-occlusion, and, apparently for the first time, described the way this condition was diagnosed by means of Doppler ultrasound. When typical sonographic features of internal carotid artery occlusion were observed (i.e., retrograde blood flow through the ophthalmic artery, altered blood flow through the ophthalmic artery, altered blood velocity pattern in the common Journal of Clinical Neuro-ophthalmology carotid artery, and lack of signal from the internal carotid artery), special effort was required in evaluating the area of the carotid bulb for a faint, sharp, hissing sound. Its recognition was reportedly difficult. Ringelstein et al. indicated that it was so faint that documentation on both the "scope" and the recording chart was generally not possible. However, the tone was said to be so typical that it was diagnostic. In seven patients, ultrasound diagnosis of pseudo-occlusion was confirmed by appropriate angiography, and in one patient without angiography the diagnosis was confirmed during endarterectomy. In the remaining patient, diagnosis was missed with Doppler evaluation, but was eventually established by means of cerebral angiography. Aspirin was shown to be effective in the secondary prevention of atherothrombotic cerebral ischemia in the apparently largest controlled trial ever conducted on the matter. Six hundred four patients were studied by Bousser et al. 10 over a follow-up period of 3 years. They were divided into three groups: 1) patients treated with aspirin 1 g a day; 2) patients treated with aspirin 1 g a day and dipyridamole 225 mg a day; and 3) patients receiving a placebo. The cumulative rate of cerebral infarction was 10% in the two treated groups, and 18.5% in the placebo group. The difference between the two treated groups considered together and the placebo group was found to be significant (p < 0.02). Analysis of results failed to show either a significant difference between the two treated groups or a difference in the efficacy of aspirin for patients of different sexes. Also of interest was the significant reduction in occurrence of myocardial infarction in the two treated groups (p < 0.05). The overall incidence of cerebral and myocardial infarction showed a strong negative correlation with treatment (p < 0.004). Clinical value of phosphorus nuclear magnetic resonance spectroscopy for investigation of cerebral metabolism was demonstrated by Cady et al. 17 in newborn infants with cerebral hypoxia. The technique allowed metabolic consequences of cellular hypoxia to be detected rapidly. As compared to values measured in a presumably normal infant, phosphocreatinine inorganic orthophosphate ratio was shown to be reduced in three infants who had suffered birth asphyxia, but increased as clinical condition improved. Infusions of mannitol solution were followed by a rapid ratio increase on four occasions in two of the infants. Demonstration that large porencephalic cysts developed in two infants some time after grossly abnormal phosphorus spectra had been demonstrated also emphasized the prognostic value of nuclear magnetic resonance. Nuclear magnetic resonance imaging of revers- December 1984 Safran ible cerebral ischemia in man was also described by Sipponen et al. 18 One reported patient presented with a ruptured intracranial aneurysm, and showed temporary aphasia and slight hemiparesis. Huber and Yasargil 19 summarized their experience with 40 carotid-ophthalmic artery aneurysms (in 33 patients) with regard to symptomatology, modern microsurgical treatment, and postoperative results. Following surgery, worsening of visual defects was noted in only four patients. The uncommon association of Wallenberg's syndrome with "en plaque" craniopharynir0ma was reported by van der Bergh and Dom2 in a 71-year-old man. The tumor was spreading along the pons, involving the posterior inferior cerebellar artery, and the basilar artery and its branches. Van der Bergh and Dom reviewed the reported etiologies of Wallenberg's syndrome, which include arteriosclerotic thrombotic occlusions, embolic occlusions, syphilitic vascular disease, brain stem tumors, metastatic carcinoma, metastatic brainstem encephalitis caused by infectious foci in Lang's herpetic brainstem encephalitis, demyelinating disease, whiplash trauma, and mechanical trauma to the vertebral artery in the neck. Pain Although the endorphin hypothesis has been accepted by many as the best explanation for the pain control with acupunctural stimulation or placebo administration, controversies about the real importance of endorphin-mediated analgesia are far from being resolved. Chapman et al.,:'1 in a recent study on acupuncture analgesia following injection of naloxone (a narcotic antagonist), were unable to demonstrate reversal of analgesia when naloxone was given. These findings did not support the assertion of endorphin as the main factor of acupuncture analgesia. Chapman et a!. suggested that there may be two kinds of acupunctural analgesia. One mechanism would be linked to the stress resulting from the acupuncture procedure itself, that induces secretion of beta-endorphin and adrenocorticotropin (ACTH), while a second mechanism would involve an acupuncture-specific nonopioid-mediated phenomenon. Relative importance of each of these mechanisms could be related to the circumstances of the acupuncture procedure. A significant stress response is less likely to occur in a human subject of laboratory research than in clinical patients. Chapman et aI., therefore, hypothesized that this may account for inconsistencies of naloxone reversal of acupuncture analgesia among the various experimental sets. 277 Recent Literature: Part III The hypothesis of endorphin-mediated analgesia in placebo treatment was partiallx supported by the study of Grevert et al., 2 who showed that administration of naloxone diminished the analgesic effectiveness of the placebo. However, naloxone did not prevent significant placebo-induced analgesia from occurring. Thermal biofeedback emerged as the treatment of choice of migraine headaches, as compared with frontalis electromyography biofeedback and relaxation technique, in a study conducted by Lacroix et al 23 with 27 patients. Although reduction in headache was observed with each method, it was most prominent with thermal biofeedback. The latter technique led to immediate and substantial improvement that lasted as long as 6 months after the end of the treatment. In contrast with the immediate effects of thermal biofeedback, those of relaxation treatment took months to develop. However, by the 6 months of followup, these patients enjoyed an improvement comparable to that of patients treated with thermal biofeedback. Headache reduction resulting from electromyography biofeedback was much smaller than that obtained by either of the other two techniques. Interestingly, reduction in migraine headache symptomatology could be correlated with changes of skin temperature in all three groups of patients. To compare the prophylactic effect of acetylsalicylic acid with that of propranolol in the treatment of common migraine, Baldrati et al. 24 conducted a double-blind crossover study in 18 patients. In comparison with the pretreatment period, both drugs reduced migraine index, frequency, duration, and severity of attacks. No correlation was found either between plasma concentration and effects of the drug, or between results in acetylsalicylic acid and propranololtreated groups. However, the number of patients involved in the study was limited. Placebo comparison was not used. The increasing number of known side-effects of propranolol is a matter of some concern. Inhibition of phagocytic activity of cultured retinal pigment epithelial cells when incubated with propranolol was recently added by Matsuda et al. 25 to the previously reported alterations in ocular metabolism induced by beta-blockers. In a review in The Lancet, Breckenridge26 addressed the problem of heterogeneity of the side effects of betablockers and stressed the importance of newly observed drug-induced effects that may constitute major risk factors. Among these are propranolol- induced increase of plasma triglycerides, decreased concentration of high-density lipoproteins, and increased concentration of low-density lipoproteins. As indicated by Breckenridge, clinical importance of these induced changes in lipid 278 metabolism is difficult to assess when overall effects of beta-blockers may be to decrease the incidence of ischemic heart disease by means of other mechanisms. In patients with atypical periodic headache, Geraud et al. 27 suggested the assessment of supersensitivity to dopamine agonist for differentiating migraine from chronic nonmigrainous headache. In a study involving 150 patients, they showed that 30 minutes after intravenous administration of 0.1 mg/kg of piribediL 94% of patients with migraine exhibited nausea, vomiting, and rapid fall in blood pressure, whereas no effect was seen in 59% of patients presenting with nonmigrainous headache. Chronic paroxysmal hemicrania has been differentiated from cluster headache by the following clinical features: 1) predominant occurrence in females, 2) frequent short attacks (15 or more per day), and 3) full relief with indomethacin. So far, a limited number of patients with chronic paroxysmal hemicrania have been described. The first British case was recently reported by Petty and Clifford-Rose. 28 "If possible the investigator engaged in research on pain in animals should try the pain stimulus on himself; this principle applies for most noninvasive stimuli causing acute pain." This suggestion was at least included in the "Ethical Guidelines of the Committee for Research and Ethical Issues of the International Association for the Study of Pain."29 Diagnostic Techniques Automated Perimetry The Peritest is a new computer-assisted perimeter, first described by Greve.30 Its efficiency was assessed recently by Greve et al.,31 Greve and Dannhein,32 and Etienne et al.,33 mainly in glaucomatous subjects. The Peritest is based on lightemitting diode (LED) technology. Two hundred six positions can be examined, using a thresholdrelated gradient adapted suprathreshold strategy. It makes possible the performance of both automatic and semiautomatic (manual) visual field examination with the same instrument. The semiautomatic procedure allows a quick control evaluation of inconsistent results. In addition, by using multiple rather than single stimuli, semiautomatic examination is performed more quickly than With the completely automatic procedure. Reliability of the patient is measured. In glaucomatous patients, the Peritest was found to be superior to routine kinetic examination, but less sensitive than careful static perimetry. An automated static perimeter/adaptometer using light-emitting diodes was described by Ernst et al. 34 It measures thresholds with lights of Journal of Clinical Neuro-ophthalmology two wavelengths (530 and 660 nm). The procedure allows assessment of rod and cone mechanisms either during dark adaptation or with full dark adaptation. The instrument has been devised primarily for the diagnosis and management of retinal disorders, but it may have applications in other clinical fields. The Competer is a computerized perimeter that was modified by Bynke and Krakau in 198235 to make it better suited to neuro-ophthalmological examination. Exploration of the central visual field (2.5° to 20° excentricity) is performed by means of 68 testpoints, and midperipheral field 20° to 35° excentricity with 44 testpoints. The sums of the threshold values in the 68 and 44 testpoints, respectively reflect the overall function of the central and midperipheral fields. Difference between the performance values in the temporal and the nasal hemifields indicates extension and depth of a defect restricted to the hemifield. In a recent evaluation, Bynke36 found that these parameters were suitable for quantitative studies in cooperative patients. Pe'er et al.37 described a method for converting visual field isopters plotted with Goldmann perimetry into digitized data for computer evaluation. The contours of the visual field isopters are traced with a stylus generating sparks at its end. Two linear microphone sensors located on adjacent sides of the table measure the time required for the sound waves to reach them. The information is fed into a computer for further processing. This method allows area calculations, graphic display and storage of patients' data, and seems relatively inexpensive and easy to perform. Contrast Sensitivity Measurements Contrast sensitivity was found by Lund et al. 38 to be greater in the lower than in the upper field. These observations correlate with the better visual acuity that has been reported in the lower part of the visual field,39 as well as with electrophysiological findings indicating a greater sensitivity in the lower visual field. 40 In normal subjects, better acuities were shown by Owsley et al. 41 to be associated with a generalized decline in sensitivity for low and intermediate spatial frequencies. These findings do not support previous observations stating that subject's acuity is not predictive of sensitivity to low and intermediate frequencies. In their analysis of changes in contrast sensitivity throughout adulthood, Owsley et al. also noted progressively decreased perception of intermediate and high spatial frequencies starting in the 20s. In addition, older adults demonstrated impairment in the processing of temporaly modulated targets. It was hypothesized that elderly subject's sensitivity loss December 1984 Safran for intermediate and high frequency bands can be attributed partially to changes in retinal illuminance, but neural involvement was not precluded. In optic neuritis, loss of sensitivity for low spatial fre~uency stimulus was found by Hess and Plant4 to be diminished with increase in temporal frequency of stimulus presentation. In contrast, loss of sensitivity for higher spatial frequency was independent of the temporal rate of stimulation. Importance of grating field size for evaluation of contrast sensitivit~ threshold was emphasized by Hyvarinen et al.4 A number of patients with optic nerve or macula disorders retained reasonably good contrast sensitivity for low and intermediate spatial frequencies, in spite of markedly reduced visual acuity. Relative preservation of contrast sensitivity can be overlooked if sensitivity is assessed by means of grating fields as small as 2° to 5° in diameter. Measuring contrast sensitivity thresholds with various grating field sizes is still another way of evaluating visual function. Even at suprathreshold levels, contrast perception in normals differs from that of amblyopes. Loshin and Levi44 provided further evidence that at all contrast levels the amblyopic eyes show prolonged reaction times as compared to nonamblyopic eyes. Following amblyopia therapy, poor correlation was found between the effects on contrast sensitivity and those on visual acuity. After stripe treatment, Lundh and Lennerstrand45 observed that some subjects displayed increase contrast sensitivity while no improvement was noted in visual acuity. Since assessment of contrast sensitivity thresholds is now an essential part of clinical evaluation of visual function, it is important to devise easy clinical tests to be used in children. They should be fast and simple for the child to understand. Maione et al. 46 proposed to fill outlines of horses with gratings of various contrast. When the grating is resolved by the eye, the picture looks like a zebra. Visual-Evoked Potentials Multiple sclerosis is probably the neurological disorder in which visual evoked potential recordings have been the most useful. This examination technique made possible a reclassification of the clinical diagnosis of multiple sclerosis in 30% of the 500 patients studied by Lowitsch. 47 Usefulness of visual-evoked potentials in the diagnosis of multiple sclerosis condition was compared to that of other electrophysiological examinations. According to Kjaer's48 personal experience with 160 patients, if multiple sclerosis patients were to be examined by only one evoked 279 Recent Literature: Part III potential technique, visual-evoked response recording should be preferred. Indeed, in comparison with brain stem auditory-evoked potentials and somatosensory evoked potentials, pattern reversal visual-evoked potentials were demonstrated to be the most sensitive technique, as well as the easiest to perform and evaluate. Brain stem auditory-evoked potentials were found somewhat less sensitive, but revealed many subclinical lesions. Somatosensory evoked potentials were as sensitive as brain stem auditory evoked potentials, but in most cases they only confirmed clinical findings. Blink reflex evaluation was a less sensitive method than evoked potential testing. Delplace and Guillaumat49 reevaluated Uthoffs phenomenon in multiple sclerosis by means of pattern visual evoked potentials. A number of diabetic subjects with no evidence of ocular changes showed altered pattern visualevoked responses. In 10 (62%) of 16 patients studied by Puvanendran et al.,50 latency was increased by more than three standard deviations, often in conjunction with severe reduction in amplitude. All cases with altered visual-evoked potentials also showed delayed sensory conduction in the median nerve. In a study of pattern visual-evoked potentials in patients with neurosyphilis, Conrad et al. 51 found altered responses in 16 (20%) out of 79 affected patients. A higher percentage of altered visual evoked potentials was noted in patients with tabes dorsalis than in patients with general paresis or meningovascular forms. Increase in latencies noted with neurosyphilis (up to 30 ms) was less marked than that reported in multiple sclerosis (up to about 100 ms). Sokol52 observed that in amblyopic eyes, pattern reversal visual evoked potentials demonstrated longer latency of the first and shorter latency of the second major positive waves. Since shorter latency of the second positive wave is normally elicited by low spatial frequency stimuli as a reflection of local luminance activity, Sokol hypothesized that the pattern of changes in latencies reported in amblyopic eyes indicated a loss of contrast-specific mechanism and activation of that of local luminance. Lithium treatment was reported by Fenwick and Robertson53 to induce a significant increase in amplitude of pattern visual-evoked potentials. In hyperactive children, stimulants speed reaction time, but without shortening visual-evoked response latency. However, as demonstrated by Halliday et aI. 54 with methylphenidate administration, minimal drug-induced changes in amplitude can occur. The nature of these effects varied according to age, so that opposite effects could occur in children under the age of 10 and older children. 280 Alteration in late occipital positive components in human visual-evoked potentials (about 270 ms after the stimulus onset) were interpreted by Kitajima et al. 55 as being due to amplitude changes of the overlapping occipital negative component occurring with latency of 250 ms, and reflecting task-specific perceptual activities. It was suggested by Whittaker and Siefried56 that low amplitude high frequency wavelets that were observed superimposed upon large slow waves reflected the earliest cortical visual processing recorded in man. They usually began 35 to 40 ms after the onset of the flash stimulus and reached a maximum at the O2 electrode locus (2.5 cm above the inion), and wavelet polarities inverted when adjacent bipolar electrode pairs were moved across the occipital region. Evaluation of Anterior Visual Pathway Function in Patients with Cataract In patients suffering from cataract, assessment of the "neural" visual acuity is important in neuroophthalmological evaluation. Recent papers dealt with assessment of visual function in these patients by various methods, all of which, however, have been found to have limitations. Blue field entoscopy is based on perception of one's own leucocytes in the parafoveolar capillaries upon diffuse illumination by light of 430 nm. Miris and Missotten57 investigated the extent to which blue field entoscopy was useful for prediction of postoperative visual acuity in patients with cataract. They noted that all 27 patients who preoperatively were able to perceive the entopic phenomenon demonstrated good postoperative visual acuity, i.e., 20/30 or better. However, the authors noted that a negative result from the test did not allow a prediction of postoperative visual acuity. The test required some cooperation from the patient. Before cataract surgery, photopic flash electroretinogram and visual-evoked response were found by Vrijland and van Lith58 to be good indications for estimating postoperative vision. When flash-evoked potential was larger than 21 /lV, 75% of 16 eyes demonstrated postoperative visual acuity of 20/25 or better. With evoked responses of 14 /lV to 21 /lV in amplitude, 52% of 98 eyes showed good postoperative acuity. Gratings of various spatial frequencies can be generated on the retina using interference franges, independently of the optics of the eye. Two commercially available instruments, the Haag-Streit visometer and the Rodenstock retinometer, were assessed by Halliday and ROSS 59 in cataractous eyes, for comparison with postoperative Snellen acuity. Results with both instruments were essentially the same. Of the 50 Journal of Clinical Neuro-ophthalmology studied eyes, 22 achieved acuity approximately equal (±25%) to the predicted value. Twenty patients saw better and eight worse than predicted. Eight patients with mature cataract failed to see the grating, a fhenomenon that had already been reported.6 Conversely, patients with amblyopia had markedly higher gratin? than Snellen acuity, as also shown previously.6 Conventional Radiology The oblique lateral projection of the orbital floor used in conjunction with usual radiological examination was advocated by Laurin and Johansen62 to permit a reliable diagnosis of blowout fractures to be reached in the majority of cases without tomography. However, it reportedly required experience for evaluation because anatomy was presented in a somewhat unusual way and the fracture was sometimes difficult to observe. Oblique lateral projection was not recommended for identifying destructive changes of the orbital floor. Minor radiological sellar changes, e.g., slight irregularity of the lamina dura, asymmetry of the sellar floor, or thinning of the dorsum sellae, could not be correlated with histopathological abnormalities in a study by Sanna et al. 63 These conclusions were reached following a multidirectional thin section tomography performed on 62 excised sphenoidal bones, and histological evaluation of the pituitary glands. Nuclear Magnetic Resonance Early results from examination of human orbit and brain with nuclear magnetic resonance imaging are promising. Mosley et al. 64 reported on their preliminary experience with orbital imaging by means of nuclear magnetic resonance. Characteristics of various orbital tissues were provided, according to imaging parameters. The lens could be clearly seen, whereas the ciliary body was poorly visualized. Aqueous, vitreous, sclera, and conjunctiva showed considerable changes in relative intensity with variation of imaging parameters. Retina, choroid and sclera were remarkably demonstrated. The optic nerve was shown on both sagittal and axial imaging, without movement artifacts in spite of the minimum time of 4.3 minutes for the scanning sequence. The superior ophthalmic vein and the optic nerve showed summation of their shadow on axial sections, as with computerized tomography scanning. Mosley et al. emphasized that this summation should not be mistaken for a lesion within the nerve. The four recti muscles and the levator palpebrae were clearly visible. With the strong signal of orbital fat, contrast was high and muscles were easily identified. The superior December 1984 Safran ophthalmic vein was clearly seen, showing a complex phenomenon called ·paradoxical enhancement." Mosley et al. stressed both the considerable superiority in many respects of nuclear magnetic resonance imaging over computerized tomography scanning and its limitations with regard to bone or calcified tissue definition. Nuclear magnetic resonance tomograms of the eye were also provided by Wollensak and Seiler.65 Wooden intraocular foreign body and ocular melanoma were noticeably delineated. Simmonds et al. 66 reported on the use of nuclear magnetic resonance imaging for human brain anatomy demonstration. Sharp gray-white matter contrast is invaluable for delineating brain structures. Moreover, it allows demonstration of myelination during childhood. The same technique was used by Sydder and Whitelaw67 for evaluating myelination of brain structures in children. Corston et al. 68 studied a variety of intracranial lesions by means of nuclear magnetic resonance multiplanar imaging. The technique permitted a precise assessment of extrasellar extension of pituitary tumors, and their relationship to the chiasm. Empty sella could be clearly differentiated from pituitary tumors. References 1. Hunt, A.: Tuberous sclerosis: A survey of 97 cases. Dev. Med. Child Neural. 25: 346-357, 1983. Reprints: Ann Hung, B.A., Research Worker, Human Development Research Unit, Park Hospital for Children, Old Road, Headington, Oxford OX3 7LQ, England 2. Winter, J.: Computed tomography in diagnosis of intracranial tumors versus tubers in tuberous sclerosis. Acta Radial. 23: 337-344, 1982. Reprints: Dr. James Winter, Department of Radiological Sciences, Neuroradiology Section, UCLA School of Medicine, University of California, Los Angeles, California 90024 3. Swift, M., Sholman, L., Perry, M., and Chase, C: Malignant neoplasms in the families of patients with ataxia-telangiectasia. Cancer Res. 36: 209-215, 1976. 4. Swift, M., and Chase, C: Cancer and cardiac deaths in obligatory ataxia-telangiectasia heterozygotes. Lancet 1: 1049-1050, 1983. Reprints: Michael Swift, Division of Medical Genetics, Department of Medicine and Biological Sciences Research Center, University of North Carolina, Chapel Hill, North Carolina 27514 5. Cunliffe, P.N., Mann, J.R., Cameron, A.H., and Roberts, K.D.: Radiosensitivity in ataxia-telangiectasia. Br. f. Radial. 48: 374-376,1975. 6. Abadir, R., and Hakami, N.: Ataxia telangiectasia with cancer. An indication for reduced radiotherapy and chemotherapy doses. Br. f. Radial. 56: 343345, 1983. Reprints: Rushdy Abadir, M.D., F.R.CR, Department of Radiation Oncology, Uni- 281 Recent Literature: Part III versity of Missouri Hospital and Clinics, Columbia, Missouri 65212 7. Tuck, R.R., and McLeod, J.G.: Retinitis pigmentosa, ataxia, and peripheral neuropathy. f. Neural. Neurosurg. Psychiatry 46: 206-213, 1983. Reprints: Dr. J.G. McLeod, Department of Medicine, University of Sydney, Sydney, NSW 2006, Australia 8. Barbieri, F., Sammartino, A, Russo, E., and De Crecchio, G.: A case of Refsum's disease without peripheral nerve involvement: Clinical, biochemical, electrophysiological and morphological aspects. Ophthalmologica 186: 71-76, 1983. Reprints: Dr. Alfredo Sammartino, Clinica Oculistica, II Facolta di Medicina, University di Napoli, Napoli, Italy 9. Salisachs, P.: Ataxia and other data reviewed in Charcot-Marie-Tooth and Refsum's disease. f. Neural. Neurosurg. Psychiatry 45: 1085-1091, 1982. Reprints: Dr. P. Salisachs, Paseo de Gracia 62, Barcelona-7, Spain 10. Beck, M.: Papilloedema in association with Hunter's syndrome. Br. f. Ophthalmol. 67: 174-177, 1983. 11. McKusik, V.A.: The mucopolysaccharidoses. In Heritable Diseases of Connective Tissue (4th ed.). CV. Mosby, St. Louis, 1972. 12. Dick, DJ, Newman, P.K., and Cleveland, P.G.: Hereditary spastic ataxia with congenital miosis: Four cases in one family. Br. f. Ophthalmol. 67: 97101, 1983. Reprints: Dr. DJ Dick, Regional Neurological Centre, Newcastle General Hospital, Newcastle upon Tyne, NE4 6BE, England 13. Ross Russell, RW., and Page, N.G.R.: Critical perfusion of brain and retina. Brain 106: 419-434, 1983. Reprints: RW. 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Bousser, M.G., Eschwege, E., Haguenau, M., Lefauconnier, J.M., Thibult, N., Touboul, D., and Touboul, PJ: Essai cooperatif de controle "ALCL.A" Prevention secondaire des accidents ischemiques cerebraux lies a I'atherosclerose par l'aspirine et la dipyridamole. 3e partie: Resultats. Rev. Neural. 139: 335-348, 1983. Reprints: M.G. Bousser, Clinique des Maladies du Systeme Nerveux, Hopital de la Salpetriere, 47 Bd de I'Hopital, F-75651 Paris Cedex 13, France 17. Cady, E.B., Dawson, M.}., Hope, P.L., Tofts, P.s., Costello, AM. de L., Delpy, D.T., Reynolds, E.O.R., and Wilkie, D.R: Non-invasive investigation of cerebral metabolism in newborn infants by phosphorus nuclear magnetic resonance spectros- 282 18 19. 20. 21. 22. 23. 24. 25. 26. 27. copy. Lancet 1: 1059-1062, 1983. 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Safran, M.D., Clinique d'ophtalmologie, Hopital Cantonal Universitaire, CH-1211, Geneva 4, Switzerland. Journal of Clinical Neuro-ophthalmology |