[A severe traffic accident--250 years ago. Medical history presentation]

During a scientific examination in July 1999 both crypts below the St. Martin's Church in Grünstadt, Germany, were opened and 9 coffins from the county family of Leiningen examined. This paper is concentrating on one of these persons: Georg Hermann (1679-1751), count of Leiningen-Westerburg-Altleiningen, who gave during the 18. century the city its barock character. He was also responsible for the rebuilding of the church. His skeleton revealed interesting pathological changes. Few years before his death the count had the accident to get run over by a heavy wagon which crushed the distal part of his legs. The fractures healed, but gave him an ancylotic and shortened left leg, which must have caused him a lot of suffering in his last years.

Optic nerve lesion following neuroborreliosis: a case report

PURPOSE

Neuroborreliosis may cause various neuro-ophthalmological complications. We describe a case with a bilateral optic neuropathy.

CASE REPORT

A 58-year-old female developed facial paresis six weeks after an insect bite. One week later she developed bilateral optic disc swelling with haemorrhages and nerve fibre bundle defects in the lower visual field of the left eye. In CSF and serum, raised IgM and IgG titres to Borrelia burgdorferi were found. Systemic antibiotic treatment led to improvement of the vision and facial paresis, but not all visual field defects resolved, probably due to ischemic lesions of the optic disc.

DISCUSSION/CONCLUSIONS

In optic nerve lesions due to neuroborreliosis it is difficult to distinguish between inflammatory and ischemic lesions. This patient demonstrated features of an ischemic optic nerve lesion.

Daytime variations in central nervous system activation measured by a pupillographic sleepiness test

Pupil size is regulated exclusively by the autonomic nervous system, and in darkness is proportional to the level of central sympathetic tone. Spontaneous pupillary movements, while at rest in darkness and quiet, were recorded for a period of 11 min, using infrared video pupillography. Thirteen young adults took part in a 30-h experiment lasting from 08.00 h to 14.00 h on the following day. Pupillographic testing and completion of a self-rated scale for the estimate of sleepiness were repeated every two hours. Pupillary unrest index (PUI), as a measure of pupil size instability associated with daytime sleepiness, showed the lowest values at 09.00 h, when pupil size was found to be maximal, and 23.00 h. During the course of the day, amplitude spectrum < or = 0.8 Hz and PUI showed increasing values during the afternoon hours, followed by a decrease during the evening. Daytime variations in the pupillary unrest index in healthy normal subjects were found to be positively correlated with the level of alertness. These findings are similar to the daytime variations found by the MSLT (multiple sleep latency test) in young adults.

[Optic neuritis as a complication in preventive tetanus-diphtheria-poliomyelitis vaccination: a case report]

BACKGROUND

The preventive value of vaccinations is generally accepted. Public recommended vaccinations are administered frequently and therefore even rare complications may occur.

PATIENT

We report on a 56-year-old patient who suffered from an acute unilateral optic neuritis, following ten days after vaccination against diphtheria, tetanus and poliomyelitis. A complete remission occurred within six weeks after intravenous megadose prednisolone.

CONCLUSIONS

Neurological and ophthalmological complications following vaccinations are rare, and in most cases reversible.

[Automated swinging flashlight test in patients with optic nerve diseases]

AIM OF THE STUDY

The swinging flashlight test is an objective method to diagnose a lesion of the anterior visual pathways. However, errors and faults may easily alter the test's results. Hence, the value of the swinging flashlight test depends highly on the examiner's skills. Therefore an automated and objective procedure was developed which is independent from the examiner.

METHODS

A binocularly measuring instrument adapted for video pupillography was supplied with two arrays of light emitting diodes in front of each eye of the subject. By means of this illumination, pupillary light reflexes are elicited alternately. Pupil size is registered continuously, and after artifact elimination, the response amplitudes of the pupils are determined as a mean of right and left pupil. Responses elicited via right and left eye are compared. By varying the stimulus intensity it is possible to measure the amount of the relative afferent pupillary defect. The procedure was tested in 31 patients with optic nerve disorders.

RESULTS

The measurements were easily feasible, stable and reliable. Correlation between the relative afferent pupillary defect detected manually by grey filter compensating and with the automated procedure proved to be high. Both variables correlated highly significant with a Spearman rank coefficient of 0.65. If the clinical test is regarded as the golden standard, the automated swinging flashlight test is able to detect 85% of the relative afferent pupillary defects > or = 0.3 logE and 94% of the defects > or = 0.6 logE.

CONCLUSION

The automated swinging flashlight test can be recommended to exclude influences by the examiner or if the exact amount of the relative afferent pupillary defect is desired, e.g. when monitoring therapeutic effects in optic nerve diseases. Furthermore, an automated swinging flashlight test could serve as a screening test.

[Effect of dorzolamide on accommodation and pupillary reaction?]

PURPOSE

To test the effect of dorzolamide on accommodation or pupillary function.

MATERIALS AND METHODS

This double-blind study examined 35 young subjects with normal ophthalmological findings. Before and after the application of two drops dorzolamide in one eye and placebo in the other eye the subjects were examined by pupillography, infrared video-retinoscopy, and subjective near-point determination.

RESULTS

None of the parameters concerning accommodation or pupillary function differed significantly before and after application of the eye drops.

CONCLUSION

Dorzolamide has no short-term effect on accommodation or pupillary function.

Laboratory, clinical, and kindergarten test of a new eccentric infrared photorefractor (PowerRefractor)

PURPOSE

Photorefraction is a convenient way to determine refractive state from a distance. It is, therefore, useful for measuring infants and noncooperative subjects. However, its reliability (or precision) and accuracy (or validity) has been questioned. In a study in subjects without cycloplegia, we have tested whether, after complete automatization, eccentric photorefraction at a 1-m distance can be as reliable as a common autorefractor.

METHODS

In a laboratory study of 15 student subjects without the use of cycloplegia (30 eyes, refractive errors ranging from -6 D to +6 D), age 25 to 31 years, the photorefractive measurements were compared with spectacle prescriptions. In a clinical study, photorefraction, autorefraction, and subjective refraction were performed in 40 patients without cycloplegia (refractive errors ranging from -4 D to +4 D), most of them with various ocular pathologies. Subjective refractions were obtained by an experienced clinical ophthalmologist but were not accessible to the examiner who used the two refractors. Visual acuity was 20/20 or better except for five subjects. Ages ranged from 6 to 75 years. In the kindergarten screening study, 108 children aged 3 to 6 years were screened for refractive errors.

RESULTS

In the laboratory study, it was found that the mean difference between spectacle prescription and PowerRefractor measurements was < 0.6 D for spheres and below 0.4 D for cylinders. In the clinical study, data were obtained by all three procedures in 78 eyes. The photorefractor and the autorefractor performed similarly for spheres (mean absolute dioptric difference between refractor and subjective measure: 0.593 D and 0.696 D) and cylinders (mean absolute dioptric differences: 0.399 D and 0.389 D). However, the photorefractor was superior with regard to the measurement of the magnitude and axis of astigmatism (mean weighted difference between objective and subjective axis 0.644 D and 0.769 D, respectively). In the kindergarten study, it was found that the PowerRefractor was very convenient to handle. The autorefractor measured more myopic refractions than the PowerRefractor (mean of the left eyes 0.11 +/- 1.1 D vs. 0.62 +/- 0.53 D, p < 0.001). There was no indication that the PowerRefractor failed to detect hyperopia, because all but one child with more than 2 D of hyperopia measured with autorefractor (n = 7) was also hyperopic with the PowerRefractor. Furthermore, presenting an interesting fixation target at a 3-m distance did not cause more hyperopic refractions, indicating that the camera of the PowerRefractor at a 1-m distance was not a significant stimulus to accommodation.

CONCLUSIONS

The PowerRefractor was shown to have comparable or slightly better reliability and accuracy than a modern autorefractor; however, it has major advantages over current autorefractors in that it is faster, measures both eyes at once, and gives interpupillary distance, pupil size, and information on the alignment of the eyes at the same time.

Xkid, a chromokinesin required for chromosome alignment on the metaphase plate

Metaphase chromosome alignment is a key step of animal cell mitosis. The molecular mechanism leading to this equatorial positioning is still not fully understood. Forces exerted at kinetochores and on chromosome arms drive chromosome movements that culminate in their alignment on the metaphase plate. In this paper, we show that Xkid, a kinesin-like protein localized on chromosome arms, plays an essential role in metaphase chromosome alignment and in its maintenance. We propose that Xkid is responsible for the polar ejection forces acting on chromosome arms. Our results show that these forces are essential to ensure that kinetochores and chromosome arms align on a narrow equatorial plate during metaphase, a prerequisite for proper chromosome segregation.

[Perimetry findings and driving performance. "How much visual field" does a motorist need?]

OBJECTIVE

On 01-01-99 the new driving licence regulations came into force. Are the visual field criteria mentioned there sufficient for an adequate evaluation of driving fitness?

METHODS

Typical (binocular) visual field defects were digitally superimposed onto photographs of traffic scenes to show the influence of such scotomata on visual perception.

RESULTS

Exemplary cases clearly show that evaluation of visual field borders alone is not sufficient for evaluating driving fitness. They also prove that binocular scotomata affecting the (para-)central region of the visual field are of special importance to driving performance. The actual guidelines given by the traffic commission of the German Ophthalmological Society (DOG) and the legally defined limits will be critically discussed.

CONCLUSION

From the ophthalmological point of view the actual visual field criteria of the new driving licence regulations do not seem to be sufficient for the evaluation of driving fitness: An additional consideration of (para-)central scotoma is mandatory. This publication provides recommendations for execution and interpretation of perimetric examinations for traffic ophthalmological purposes.

Spontaneous fluctuations in pupil size are not triggered by lens accommodation

Fluctuations in pupil size and lens accommodation are measured concurrently under open loop conditions, constant illumination and far fixation. In 12/17 trials no correlation was measured between the fluctuations in pupil size and lens accommodation. For the remaining 5/17 trials no lag was observed between the changes in pupil size and lens accommodation indicating that this correlation does not arise as a consequence of a near response. These observations suggest that under conditions of constant illumination and far fixation, the supranuclear centers controlling the near response are not active.

Microembolic signals and clinical outcome in patients with acute stroke--a prospective study

The occurrence of microembolic signals (MES) in patients with transient ischemic attack (TIA) or stroke has already been described; the influence of the time interval between onset of symptoms and transcranial Doppler monitoring (TCD) on the MES rate or MES prevalence and the possible prognostic value of the early detected MES rate on the outcome of TIA or stroke symptoms in a 3 month interval are discussed. In a prospective study we evaluated 61 patients consecutively admitted to our stroke unit after their first ischemic neurological deficit involving the vascular territory of MCA and/or ACA. All of the patients underwent a 30-minute bilateral transcranial Doppler monitoring of their MCAs for the identification of MES. Monitoring was performed within 12.3 + -9.3 (average mean + -SD) hours of stroke onset for the first time, the second time 48 hours after first TCD monitoring. Prognosis for the recovery of neurological deficits was evaluated by using the Barthel index (BI) and Scandinavian Stroke Scale (SSS) at the time of admission of the patient to the stroke unit, and with Barthel indices after one month and after 3 months. As a result, 56% of all patients showed MES in at least one of the two registrations. MES were recorded not only on the symptomatic side. The MES prevalence between both TCD monitorings was significantly different (total MES prevalence: 1st TCD: 26 patients: 2nd TCD: 13 patients; p < 0.04; ipsilateral MES prevalence: 1st TCD: 19 patients; 2nd TCD: 9 patients; p < 0.01). The regression analysis showed a significant influence of the total MES rate on both neurological scores at admission (SSS: 0.03; Barthel index: 0.04), but not for the Barthel scores after one and three months. In conclusion, we found an influence of the time interval between onset of neurological symptoms of TIA or stroke on the MES rate and the prevalence of MES. The prevalence of MES or the MES rate, found after a short time interval to the onset of symptoms, did not have a prognostic value on the outcome of neurological deficits up to a three month follow-up.

Pupil perimetry using M-sequence stimulation technique

PURPOSE

M-sequence stimulation technique allows mapping of the retinal function by multifocal electroretinographic (ERG) recordings. However, the information provided about visual field is limited to retinal function. Optic nerve diseases and diseases of the higher visual pathways usually show normal multifocal ERGs. Using pupillary responses instead of the electrical retinal responses might enhance the diagnostic possibilities of this system. The problems of local ERG recordings are very similar to those encountered in pupil perimetry: Local stimuli have to be dim to avoid or at least reduce stray-light responses. Dim stimuli, close to the absolute threshold, elicit only subtle pupillomotor responses. Therefore, techniques that are able to detect small focal responses are promising.

METHODS

Pupillography was done by means of an infrared video camera and real time image processing (50 Hz) using a custom-designed videoboard in a personal computer (486). Recording conditions: The stimulus was presented on a monitor (75 Hz) in 26 cm distance from the patient's eyes. It contained 37 hexagons in a 25 degrees visual field. Each element changed between black (1.6 cd/m2) and white (160 cd/m2) after a binary M-sequence independently from other elements. Four thousand ninety six different stimulus pictures of 120-msec duration were shown during a single pupillogram recording. Thirty-seven local pupillograms were calculated in a cross-correlation of stimulus sequence and the pupil diameter.

RESULTS

The pupillomotor fields in normals showed a shape and sensitivity distribution as known from conventional pupil perimetry techniques. Artificial paracentral scotomas (5 degrees) created by masking different locations could be demonstrated convincingly. Even in patients with optic nerve lesions it was possible to demonstrate visual field defects.

CONCLUSIONS

Pupil perimetry using the M-sequence technique is a promising method of objective perimetry that may find its entrance into clinical application.

Naso-temporal asymmetry and contraction anisocoria in the pupillomotor system

BACKGROUND

Differences between the pupillomotor sensitivity of nasal and temporal retinal hemifields may contribute to the relative afferent pupillary defect (RAPD) seen in optic tract or pretectal lesions. To understand the architecture of the pupillary pathway, it is necessary to know the size and the prevalence of such naso-temporal differences and also of contraction anisocoria (unequal direct and consensual pupillary responses) in normal individuals. The results of previous studies have been only partially consistent.

METHODS

We registered the direct and consensual pupillary light reactions in both central retinal hemifields of 42 healthy subjects by means of IR video pupillography. Stimuli were generated under mesopic conditions on a computer screen as half-circles with 4.6 cd/m2 and 10 deg radius. Stimulus duration was 200 ms with a stimulation interval of 4 s.

RESULTS

The nasal retina was significantly more sensitive than the temporal retina, and the direct pupillary reactions were significantly larger than the consensual reactions. For the nasal retina, direct pupillary reactions exceeded the consensual reactions, whereas there was nearly no difference between direct and consensual reactions for the temporal retina.

CONCLUSION

RAPD in optic tract damage or pretectal lesions cannot be explained by the only slightly more sensitive nasal retina. Considerably more input would be needed from the contralateral than from the ipsilateral retina into the optic tract. The nearly equal direct and consensual pupil reactions when stimulating the temporal retina suggest an input of temporal retina to both sides of the pretectum. Such a crossing of temporal fibres may take place in the chiasm.

[Carcinoma-associated retinopathy: a review with clinical examples]

Cancer-associated retinopathy (CAR) is a rare paraneoplastic syndrome. In this survey we report about two further patients with CAR, who were referred to the University Eye Hospital of Tuebingen within a few months. The most common primary tumor associated with CAR is small cell carcinoma of the lung. Case reports about rhabdomyosarcoma, carcinoma of the endometrium, prostate and mamma were also described. The exact pathogenesis of CAR is still unknown. Specific autoantibodies were found against the photoreceptor protein recovering (23-kd retinal CAR antigen). However, this reaction is not present in all patients, and probably other antigens are also involved. Most of the patients experience symptoms of CAR before the primary tumor is detected. Besides glare sensitivity and flashing lights, a rapidly progressive, often asymmetric visual loss may occur. Although paracentral and mid-peripheral scotomas can be found frequently, visual field defects are often quite heterogeneous. Typically, the responses in the electroretinogram (ERG) are markedly reduced, but normal ERGs were also described. The fundus picture in CAR shows sheathing of the retinal vessels, narrowing of the arterioles and clumbing of the retinal pigment epithelium. The prognosis is poor. Frequently there is progression to bilateral loss of vision within a few months. Treatment of the primary tumor does not seem to alter the ocular prognosis. Systemic corticosteroids may be helpful in some patients. Nevertheless, no proven therapeutic regimen is currently available.

[Bilateral optic disk edema in polyneuropathy, organomegaly, endocrinopathy, monoclonal proteins and skin changes (POEMS syndrome)]

BACKGROUND

POEMS occurs only in about 1% of plasmocytoma cases, but in more than 50% of the rare osteosclerotic subtypes and plasma cell dyscrasias. The estimated frequency is 20 cases per year in Germany. Swelling of the optic disks is an early sign of the syndrome.

CASE REPORT

An osteosclerotic plasmocytoma type IgA lambda was known in a 63-year-old farmer for 4 years. The primary lesion in the left femur was irradiated at diagnosis. Half a year prior to our examination the patient experienced edema of the legs and recurrent diarrhea. A staging confirmed the earlier diagnosis of a POEMS syndrome. The patient was presented for ophthalmologic examination because of optic disk swelling and progressive visual field defects: raster perimetry revealed enlarged blind spots and increased thresholds. Neurologic examination revealed polyradiculitis, increased protein levels in the cerebrospinal fluid and intracranial hypertension. The patient was treated with oral steroids which entailed improvement of the visual fields and decrease of optic disk swelling.

CONCLUSIONS

Ophthalmologists play an active role in the staging, in the ruling out of other causes, and in the treatment. Symptomatic treatment with oral steroids should be monitored with visual acuity, raster perimetry and fundus examinations.

[Bilateral neuroretinitis with zoster infection]

BACKGROUND

Infections with varicella zoster virus may involve the optic nerve and the retina. Different pathomechanisms have been discussed. We present a case with an autoimmune inflammatory reaction according to the clinical course.

PATIENT

A 69-year-old female was referred to our clinic because of suspected bilateral anterior ischemic optic neuropathy. She complained of severe visual loss the day before admission. Her ophthalmological and general history was unremarkable apart from treatment with 5 to 7.5 mg prednisolone alternately because of rheumatoid arthritis. Best corrected visual acuity was 1/15 OD and 0.1 OS. A relative afferent pupillary defect on the right eye was present. Optic disc oedema with multiple hemorrhages of the retina extending into the peripheral funds, slightly attenuated retinal arteries and macular oedema were seen fundoscopically in both eyes. THERAPY AND CLINICAL OUTCOME: After immediate treatment with steroids (initial dose 250 mg prednisolone per day) visual acuity improved. Because of a clinically suspected and serologically proven active varicella-zoster infection an additional virostatic therapy with valaciclovir was started and steroids were lowered gradually. Within 2 months, visual acuity increased to 0.8 OD and 1.0 OS. Oedema of optic discs and macula resolved and retinal hemorrhages disappeared.

CONCLUSION

A severe hemorrhagic neuro-retinitis involving the optic discs was seen in the course of a varicella-zoster infection, possibly reactivated by chronic steroid therapy of a rheumatoid arthritis. Because of the normalization of visual function an ischemic pathogenesis is unlikely. An autoimmune inflammatory reaction seems to be the predominant mechanism, supported by the good effect of steroid and valaciclovir therapy.

Pupillary light reflexes in patients with Leber's hereditary optic neuropathy

BACKGROUND

According to a recent pupillographic study, patients with Leber's hereditary optic neuropathy (LHON) show the same pupillary behaviour as normals. Because this raises many questions concerning the real nature of LHON and challenges our concept of the afferent pupillary system, we tried to verify the results of this study.

METHODS

Pupillary function was assessed in 34 normal subjects and 40 patients with LHON. Pupillary light reflexes were recorded by means of the Compact Integrated Pupillograph (CIP, AMTech). Under mesopic conditions 200-ms stimuli were presented at two different stimulus intensities. Latency, constriction amplitude and baseline diameter were defined automatically. Pupil light reflexes were compared between LHON patients and normals and between the better and the worse eye in 20 LHON patients with different visual acuities.

RESULTS

For both stimuli there were significant differences in latency between LHON patients and controls. The latency of the pupil light reflex proved to be about 20 ms longer for LHON patients, and the amplitude was significantly smaller for the bright stimulus. Within LHON patients, the eyes with the worse visual acuity had a significantly smaller constriction amplitude than the eyes with the better visual acuity.

CONCLUSION

The results of our study confirm that LHON really is an optic nerve disease and that the pupillary light reflexes are not normal.

[Optic neuropathy after erythema infectiosum]

BACKGROUND

Optic neuropathies can not always easily be classified as neuritis or ischemic disease.

CASE REPORT

A 39 year old woman suffered from unilateral optic neuropathy 9 days after the acute onset of a general disease with erythema and joint swellings. The optic disc swelling and visual fields resembled an anterior ischemic optic neuropathy, however, a marked improvement was achieved by steroid treatment. The general disease proved to be erythema infectiosum.

CONCLUSIONS

Erythema infectiosum as a frequent children's disease causes very rarely central nervous involvement, optic neuropathy has not been reported yet. In cases of atypical optic neuropathies search for an underlying systemic disease is of value.

Pupillographic sleepiness testing in hypersomniacs and normals

BACKGROUND

Pupillary oscillations in darkness are considered to be a sign of sleepiness. The purpose of this pilot study was to ascertain whether pupillary oscillations were more pronounced in patients with hypersomnia than in normals.

METHODS

Seven patients (four with sleep apnea syndrome, three with narcolepsy) and seven age-matched controls underwent pupillography for 11 min in complete darkness. The changes in pupil size were analyzed mathematically to determine quantitatively the amount of pupillary instability.

RESULTS

Hypersomniacs had much higher amounts of pupillary oscillations in darkness than normals. The differences were significant. Baseline pupil size did not differ significantly between the two groups.

CONCLUSION

This study showed that a pupillographic sleepiness test based on the evaluation of spontaneous pupillary changes in darkness is applicable in hypersomniacs and may facilitate therapy control, i.e. diagnostic grading by measuring daytime sleepiness objectively.

Mathematical procedures in data recording and processing of pupillary fatigue waves

Spontaneous pupillary behaviour in darkness provides information about a subject's level of vigilance. To establish infrared video pupillography (IVP) as a reliable and objective test in the detection and quantification of daytime sleepiness, the definition of numerical parameters is an important precondition characterising spontaneous pupil behaviour adequately for further statistical procedures. The correct measurement of the pupil size, even if the lid or eyelashes are occluding the pupil, is of particular concern when testing vigilance. In this case many edge points of the pupil are detected and a fitting procedure is described that fits these edge points to a circle and excludes outliers. The first step of data preparation consists of a mathematical artefact management consisting of blink detection and elimination, followed by interpolation. Second, a fast Fourier transformation is carried out for frequencies from 0.0 to 0.8 Hz for each time segment of 82 s. Results are given in absolute and relative power of each frequency band per time segment and mean values over the entire record of 11 min. Third, the changes of the mean pupillary diameter per data window against time are shown graphically. An additional parameter referring to the pupil's tendency to instability, the pupillary unrest index (PUI), is defined by cumulative changes in pupil size based on mean values of consecutive data sequences. These mathematical procedures provide a high level of quality in both data collection and evaluation of IVP as an objective test of vigilance. In a pilot study, the pupillary behaviour of two groups were measured. One group rated themselves as alert (ten men), the other group as sleepy (12 men). The power and PUI were compared using the Mann-Whitney U-test. Both parameters show significant differences between the two groups.

Neuro-ophthalmology of pupillary function--practical guidelines

An overview how to examine pupillary function and handle pupillary abnormalities is presented. The following issues are discussed: swinging flashlight test, clinical relevance of a relative afferent pupillary defect, anisocoria with normal light reaction, diagnosis and evaluation of Homer's syndrome, differential diagnosis of impaired light reaction, tonic pupil, third nerve palsy, supranuclear pupillary disorders, iris problems, systemic disease, measurement of sleepiness, and pupillography.

Pupillographic assessment of sleepiness in sleep-deprived healthy subjects

Spontaneous pupillary-behavior in darkness provides information about a subject's level of sleepiness. In the present work, pupil measurements in complete darkness and quiet have been recorded continuously over 11-minute period with infrared video pupillography at 25 Hz. The data have been analyzed to yield three parameters describing pupil behavior; the power of diameter variation at frequencies below 0.8 Hz (slow changes in pupil size), the pupillary unrest index, and the average pupil size. To investigate the changes of these parameters in sleep deprivation, spontaneous pupillary behavior in darkness was recorded every 2 hours in 13 healthy subjects from 19:00 to 07:00 during forced wakefulness. On each occasion, comparative subjective sleepiness was assessed with a self-rating scale (Stanford Sleepiness Scale, SSS). The power of slow pupillary oscillations (< or = 0.8 Hz) increased significantly and so did the values of SSS, while basic pupil diameter decreased significantly. Slow pupillary oscillations and SSS did not correlate well in general but high values of pupil parameters were always associated with high values in subjective rating. Our results demonstrate a strong relationship between ongoing sleep deprivation and typical changes in the frequency profiles of spontaneous pupillary oscillations and the tendency to instability in pupil size in normals. These findings suggest that the results of pupil data analysis permit an objective measurement of sleepiness.

[Objective assessment of visual field defects using multifocal electroretinography]

BACKGROUND

Multifocal electroretinography allows simultaneous recording of 61 focal electroretinographic signals from the retina of the posterior pole. The function of the outer retinal layers can be mapped for a visual field of 30.5 degrees radius. We herein describe the topography of such potentials in patients with hemianopic and concentric visual field defects.

SUBJECTS AND METHODS

Six patients with visual field defects caused by chorioretinal and central visual pathways diseases were examined using multifocal ERG.

RESULTS

In 30 normal volunteers in the entire 30 degrees visual field clear signals were obtained. In the patients with visual field defects caused by retinal diseases in areas with reduced light sensitivity diminished electroretinographical activity was found. In contrast, in patients with bitemporal hemianopsia due to a chiasmal lesion no correlation between visual field and magnitude of focal ERGs was seen.

CONCLUSIONS

In retinal disorders defects in multifocal ERG presented the similar pattern as scotomata in perimetry. The patient with visual field defects due to disturbances in the chiasma exhibited a normal ERG-topography. In patients with visual field defects multifocal ERG supported differentiation of the location of the lesion.

[Pneumocysts juxta-articular to the ilial bone and the sacral bone]

PURPOSE

The purpose of the study was to detect and safely diagnose pneumatocysts by means of computed tomography.

METHODS

From September 1995 to May 1996 computed tomography of the pelvis was performed in six patients for various indications. A slice thickness of 8 mm was employed for all studies. One patient had undergone surgery for hyperparathyroidism nine years previously. Attenuation values within the coincidentally diagnosed pneumatocysts were obtained.

RESULTS

We found a total of 14 pneumatocysts juxtaarticular to the sacroiliac joint. Three patients demonstrated a bilateral intraarticular vacuum phenomenon, yet a joint communication was not found. The lesions did not coincide with inflammation, tumour or trauma.

CONCLUSION

Pneumatocysts are benign bone lesions associated with arthrotic changes of the sacroiliac joint. Computed tomography is the modality of choice for the diagnosis of pneumatocysts.

Side effects from increased doses of carbamazepine on neuropsychological and posturographic parameters of humans

Patients taking anticonvulsant drugs display a broad spectrum of side-effects. Particularly, in the beginning of treatment and with increasing doses of carbamazepine, side effects such as dizziness, ataxia, drowsiness and reduction of alertness occur, which improve some days after the dose has reached a stable level. Our aim was to find objective parameters for grading these side effects and to differentiate between neurophysiological and neuropsychological side effects of carbamazepine in a clinical situation. Twenty-two patients with trigeminal neuralgia were included for a follow-up study with increasing carbamazepine doses (0 mg to 600 mg). The effect of carbamazepine on postural stability was quantified by posturography. Different neuropsychological tests to study cognitive effects of carbamazepine were performed. The composite equilibrium score showed a significant reduction of postural stability with increasing doses of carbamazepine. In sensory analysis the somatosensory ratio was significantly influenced by increased doses of carbamazepine during the study. Mean reaction time of tonic alertness and physical alertness varied significantly with different doses of carbamazepine. There was a significant influence in patients attention during trail making tests and divided attention tests with increase in carbamazepine. In conclusion our observations show that the rate of change of carbamazepine doses is an important determinant of cognitive and motor functions in the phase of increasing doses.

[Relation between relative afferent pupillary defect and suprathreshold automated perimetry]

The purpose of this study was to test for correlation between relative afferent pupillary defect (RAPD) and visual acuity, central differential light threshold and visual field defect measured by suprasthreshold automated grid perimetry.

METHODS

In 98 patients with optic neuropathies of different origin (inflammatory, ischemic, or compressive) in addition to a standard ophthalmological examination, static perimetry of the 30 degrees visual field with a dense grid of test spots, including measurement of the central differential light sensitivity, was done by means of the Tübingen Automated Perimeter. RAPD was tested using the swinging flashlight test quantified with neutral density filters.

RESULTS

Visual acuity and central differential light sensitivity correlated only weakly with the RAPD. The visual field showed a better correlation (coeff. of corr. for all patients 0.58, for patients with optic neuritis 0.64. for patients with AION 0.53 and for patients with compressive neuropathies 0.84). One test spot not seen in perimetry corresponded to an RAPD of about 0.01 log-units.

CONCLUSIONS

The results confirm those from previous studies obtained by threshold perimetry. The RAPD is a good parameter for the severity of an optic nerve lesion, especially of compressive origin.

Source of cerebral microembolic signals in occlusion of the internal carotid artery

BACKGROUND AND PURPOSE

There are several possible sources of cerebral embolic ischaemia distal to an occlusion of the internal carotid artery (ICA). Our aim was to identify the source of microembolic signals in the ipsilateral middle cerebral artery (MCA) by taking simultaneous bitemporal transcranial Doppler ultrasound recordings of the ipsilateral MCA and the contralateral ACA to find the route of potential microembolic material to MCA.

SUBJECTS AND METHODS

The study group consisted of 38 patients with an occlusion of the ICA. With extracranial duplex sonography (ACUSON 128 XP; 7 MHz), performed by an experienced sonographer, the echo intensity and echo structure of the occluded ICA in the extracranial part (proximal) were classified as homogeneous or inhomogeneous. In addition, affected segments of the ipsilateral and contralateral carotid artery with arteriosclerotic vessel walls were compared. Microembolic signals were recorded with transcranial Doppler (TCD) monitoring. The microemboli counts in the MCA and ACA were added to the sum scores.

RESULTS

The number of affected segments of the carotid artery on the ipsilateral (the bifurcation, the external or common carotid artery) and contralateral side of occluded ICA were equally distributed. In ipsilateral MCA 3.1, 7.1 microemboli (average mean, SD) with a range of between 0 and 34 were counted, in the contralateral ACA 0.3, 0.6 (range of between 0 and 2). Regression analysis confirmed the non-predictability of the microemboli variance on the ipsilateral side of the occlusion from the variance on the contralateral side (multiple r: 0.024). We found no significant correlation between the echo intensity or echo structure of the occluded artery and an increased rate of microemboli in the ipsilateral MCA.

CONCLUSIONS

Our results indicate a predominantly ipsilateral source for cerebral microemboli in ICA occlusion. The rate of cerebral microembolic signals was not influenced by the echo structure and echo intensity of the occluded ICA.

[The pupil and retrogeniculate visual pathway. Overview]

Classically, the pathway serving the pupillary light reflex is considered to be a simple reflex arc consisting of the retinal ganglion cells, intercalated neurons in the midbrain, the oculomotor nerve and short ciliary nerves. Investigations in patients with lesions of the postgeniculate visual pathways showed that the pupillary pathway is more complex than previously assumed. The retrogeniculate visual pathway is also involved in the pupillary light reaction.

[Pupillography for objective vigilance assessment. Methodological problems and possible solutions]

To measure vigilance disorders in healthy normals or in patients (narcolepsy, sleep apnea syndrome) is difficult, time-consuming and hardly objective with present methods. Recording and analysis of spontaneous pupillary behaviour in darkness by infrared video pupillography is an objective and time-saving method to measure daytime sleepiness. However, certain external conditions must be satisfied (avoid light, noise, stress) to get reliable results. Spontaneous pupillary oscillations are recorded in darkness over 10 min and data are analyzed by fast Fourier transformation, with additional calculation of the mean pupillary diameter for each time segment (approx. 1 min). While in the alert normal, pupil remains dilated during the measurement in darkness and oscillates with an amplitude below 0.3 mm and a frequency about 1 Hz, there are characteristic changes in fatigue: (1) low-frequency components dominate the spontaneous pupillary oscillations, with an amplitude reaching several millimeters, and (2) pupil diameter decreases with time. Infrared video pupillography could play a role as a screening method and therapy control for hypersonic patients (most frequent: sleep apnea syndrome) with excessive daytime sleepiness. An objective, time-saving method like infrared video pupillography would be useful in sleep medicine and psychiatry when testing the level of vigilance, and in psychology or industrial medicine as well, providing informations about acute vigilance problems in healthy normals.

Interaction of the indirectly acting topical sympathomimetics cocaine and pholedrine

In suspected Horner's syndrome, cocaine eye drops are applied to verify the diagnosis. Subsequent application of hydroxyamphetamine or pholedrine eye drops allows localization of the site of the interruption in the oculosympathetic pathway. In the present study the influence of cocaine on subsequent pholedrine testing was examined. Cocaine 5% and pholedrine 5% eye drops were applied to eight (72-h interval only six) normal volunteers with light-colored irides. The ages of the subjects ranged from 23 to 40 years. Eye drops were applied to the same eye at varying intervals of up to 72 h, with the cocaine being given between 8:30 and 9:30 a.m. Pupil diameters were recorded by means of a frame-grabber card in a personal computer and were subsequently measured before and at 50-60 min after each drug application in 1.7 cd/m2 ambient light. In the absence of pretreatment with cocaine, pholedrine changed the mean pupil diameter from 6.89 to 8.57 mm. At 12 h after cocaine pretreatment the pupil remained dilated. Pholedrine dilated the pupil further, from 7.69 to 8.61 mm. When cocaine was given 24 h before pholedrine, the pupil dilated from 6.75 to 8.25 mm; at 48 h after cocaine application, pholedrine dilated the pupil from 6.14 to 8.20 mm; and at 72 h after cocaine pretreatment, pholedrine dilated the pupil from 5.74 to 8.00 mm. As compared with the mean diameter of the untreated contralateral pupil, the pholedrine-induced dilation amounted to 2.32 mm in the absence of cocaine pretreatment, 1.04 mm at 12 h after cocaine application, 1.29 mm at 24 h after cocaine administration, 1.89 mm at 48 h after cocaine pretreatment, and 2.18 mm at 72 h after cocaine application. The residual cocaine effect interfered with the mean pupil dilation produced by pholedrin for at least 48 h. To ensure that the sensitivity of the pholedrine test is maximal, the examiner should delay its use for more than 48 h after the cocaine test.

Ormond's disease or aortic aneurysm? Case reports

This paper presents three case reports as a basis for discussing the differential diagnosis of retroperitoneal processes and for describing the possibilities and limitations of diagnostic imaging procedures. A definitive differentiation is not possible by CT and MRI alone, but always requires histologic confirmation. Nevertheless, imaging procedures are indispensable for assessing the extent of a lesion and for follow-up. On the basis of the cases presented here and reports in the literature, it can be hypothesized that benign retroperitoneal fibrosis is caused by a chronic inflammatory or autoimmune response of the vessels since the vast majority of cases are associated with pronounced wall abnormalities of the abdominal aorta.

Multi-layered perceptron as a model for the pupillary pathway

Derived from models of neural networks, a model for the pupillary pathway is introduced that can easily be handled computationally and analytically. To model the binocular pupillary reactions we use a feed-forward network, namely, a multi-layered perception. It is possible to calculate the pupillary reactions analytically as a function of the light stimuli of the retinal hemifields, on the one hand, and the set of neural couplings between the neural layers, on the other. Several lesions, e.g., lesions of the intercalated neurons between the afferent and efferent pupillary pathways, can be simulated within the model and the corresponding pupillary reactions such as anisocoria or relative afferent pupillary defects (RAPD) can be calculated analytically. Due to its neural network structure the model described herein can easily be extended to much more complex pupillary pathways while remaining calculable computationally and analytically.

[Mobilization of intraocular foreign bodies by magnetic resonance tomography]

A 49-year-old patient suffered from a binocular perforating trauma with metal foreign bodies in 1974. During an MRI examination in 1992 for a lumbar spine herniation a metal foreign body was mobilised from the deeper vitreal and retinal area, now causing optical disturbances freely floating in the anterior vitreous. Refusing an operation, the patient, an electrical engineer, tried himself to remove the foreign body out of the optical axis by exposing his head to the electro-magnetic field of an induction coil (pulsed magnetic induction B at t0 of 0.26 Tesla). The foreign body was split into multiple small parts no longer disturbing the patient. To early detect a siderosis regular ophthalmological controls including ERG are necessary. This example stresses that even small intraocular metal foreign bodies are a contraindication for the usually applied field strength of MRI examinations.

[Pupillography as an objective attention test]

Infrared video pupillography (IVP) allows continuous recording of spontaneous pupillary oscillations in darkness which change characteristically with fatigue. Pupil size in darkness is age-related, has its maximum in the second decade and subsequently decreases during life time. Normally, the pupil oscillates in darkness with a frequency of about 1 Hz and amplitudes of less than 0.3 mm. Excessive daytime sleepiness causes instability of this pupillary behaviour which is constant in alert normals, and so called fatigue waves appear with an amplitude reaching several millimeters. The frequency profile is dominated by slow frequencies below 0.5 Hz, while average pupil size decreases continuously with time. As IVP is an objective and time-saving method it could become an important supplement to test procedures used in sleep medicine and sleep research to measure daytime sleepiness.

Vascular risk factors for atherosclerotic plaque progression in carotid artery

Two-dimensional ultrasound is a widely used technique for the clinical assessment of carotid atherosclerosis. We measured volumes of atherosclerotic plaques in carotid arteries in 70 patients with a newly developed and tested three-dimensional ultrasound method over a period of twelve months to determine the relation between progression or regression of plaque volume and vascular risk factors. In multiple regression analysis of age, size, smoking, total cholesterol, HDL-cholesterol, HDL/total cholesterol ratio, LDL-cholesterol, triglycerides, HbA1, diastolic and systolic blood pressure, the strongest predictor of plaque progression (p < 0.01) was diastolic blood pressure, diabetes came next (p < 0.05). The optimal adjustment of all risk factors showed a significant influence on plaque progression (r: 0.76).

Influence of vascular risk factors for atherosclerotic carotid artery plaque progression

BACKGROUND AND PURPOSE

Investigations regarding arteriosclerosis of carotid arteries showed an association between increased intima-media thickness and vascular risk factors. A newly developed three-dimensional ultrasound method increases the reproducibility of plaque volume measurements because more exact volume measurements can be performed with a reduction of the disadvantages of two-dimensional measurements. In a pilot study the influence of vascular risk factors on carotid artery plaque progression was examined.

METHODS

Volumes of atherosclerotic plaques in carotid arteries in 54 patients were measured with a three-dimensional ultrasound system during a 12-month period to determine the relationship between progression or regression of plaque volume, vascular risk factors, dose of aspirin, and flow turbulence in the plaque region.

RESULTS

A progression of plaque volume occurred in 67% (36/54) of all plaques. In no plaque was a regression of plaque volume seen. The optimal adjustment of all risk factors showed a significant influence on plaque progression (r = .31). Diastolic blood pressure was the strongest predictor of plaque progression (P < .01), followed by diabetes (P < .03). Turbulence in the plaque region was found in 78% of the patients in the progression group (n = 36) versus 61% in the nonprogression group (n = 18) but was not significant. Dose of aspirin (100 mg versus 250/300 mg) had no influence on plaque volume after 1 year.

CONCLUSIONS

Treatment of vascular risk factors reduces the progression of carotid artery plaque volume in three-dimensional ultrasound. The most important factor for plaque progression is a high diastolic blood pressure. Turbulence in the flow pattern and the examined doses of aspirin showed no significant influence.

[Atypical optic neuritis in systemic lupus erythematosus (SLE)]

HISTORY AND CLINICAL DATA

A 67-year-old woman experienced acute unilateral visual loss accompanied by pain with eye movements. There was a marked relative afferent pupillary defect and a nerve fiber bundle defect in the upper half of the visual field. Optic discs were normal. After 4 days vision worsened to motion detection and only a temporal island was left in the visual field. The optic disc margin was blurred. Since thirty years she had been suffering from renal insufficiency. Immunoserologic examination revealed elevated ANA and DS-DNA antibody titers. An optic neuritis in systemic lupus erythematosus was diagnosed, which is called atopic, because of its association to a systemic disease and the old age of the patient.

TREATMENT AND FOLLOW UP

The patient was treated with 100 mg prednisolone/day, slowly tapered. Within 6 weeks visual acuity improved to 0.6 and visual field normalized except for a small nerve fiber bundle defect.

CONCLUSION

Autoimmune optic neuritis often responds to treatment with corticosteroids. Early onset of treatment is important. Immunopathologic examinations are an important diagnostic tool in atopic optic neuritis. Their results may even have consequences for the treatment of the underlying disease.