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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Since 1984, there has been a great interest in the phenomenon of a particular seasonally recurrent mood disorder called seasonal affective disorder (SAD) or winter depression and its treatment: the phototherapy. Seasonal affective disorder is a syndrome described by Rosenthal in 1984. This mood disorder is characterized by depression with onset recurrent in autumn or winter and spontaneous spring or summer remission. It is associated with hypersomnia, anergia, increased appetite, weight gain and carbohydrate craving. The population prevalence in the north of the USA is estimated between 3 and 5%, but it changes with sex, age and also latitude. A long time ago, we know that animals are photoperiod sensitive and that the melatonin secretion in mammals is suppressed by the light. In 1980, Czeiler reported for the first time that human melatonin secretion can be suppressed by high light exposure (+/- 1500 lux). In 1982, Rosenthal, Lewy and al. reported an antidepressant effect of light exposure of a manic-depressive patient. The phototherapy was born. To treat the SAD, the most common procedure of phototherapy is to expose the subject during 2 hours early in the morning, between 06:00 and 09:00 AM. The subject is sitting before a light screen, he can work and has to fix the screen one time every minute. The most common side effects are headache, eyestrain, muscle pain. The ocular phototoxicity is controversed and it seems to be potentially dangerous if phototherapy is associated with tricyclic antidepressants, neuroleptics and other medication containing a tricyclic, heterocyclic or porphyrin ring system. Since this finding, many questions are asked about photoperiod and its effects in the human being. Lewy proposes for the winter depression the hypothesis of a phase delayed circadian rhythm, that can be treated by a morning light exposure. At the present time, many trials are going on to study the effects of phototherapy in other problems like insomnia, maladaptation to night work, jet lag and Alzheimer disease.
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PMID:[Seasonal affective syndrome and phototherapy: theoretical concepts and clinical applications]. 868 79

Computer video display terminals have revolutionized the home and office work habits of millions of people. Although no verifiable organic ocular diseases have been shown to derive from computer monitors, symptoms related to eyestrain are very common. Some 10% to 15% of patients presenting for routine eye exams complain of computer-related headache and eyestrain. Comprehensive ocular examination including distance, intermediate and near refraction, as well as uncovering evidence of ergonomic and lighting inadequacy, often is clinically quite helpful. A careful eye exam with particular attention to middle and near range refraction, oculomotor balance, the workstation, lighting, and seating comfort will assist measurably in alleviating eyestrain.
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PMID:Computers and eyestrain. 871 24

A recent double-masked placebo-controlled trial has confirmed that some children experience a reduction in symptoms of eyestrain and headache when they read through individually prescribed coloured filters and has shown that this benefit cannot be solely attributed to a placebo effect. People who are helped by coloured filters in this way have been described as having "Meares-Irlen syndrome'. We investigated the mechanism of this benefit by studying the optometric and visual perceptual characteristics of the children in the double-masked study. This population had normal refractive errors and heterophorias (none of the subjects had strabismus). They demonstrated slightly, but significantly, reduced amplitudes of accommodation and vergence and poor stereo-acuity. However, these factors seemed to be correlates of Meares-Irlen syndrome rather than the underlying cause. Pattern glare, a sensitivity to striped patterns (e.g. lines of text), was prevalent in our sample and was significantly associated with the subjects' symptoms. The spatial contrast sensitivity function was normal.
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PMID:A preliminary investigation into the aetiology of Meares-Irlen syndrome. 879 97

Visual correlates of specific learning difficulties (SpLD) include: binocular instability, low amplitude of accommodation, and Meares-Irlen Syndrome. Meares-Irlen Syndrome describes asthenopia and perceptual distortions which are alleviated by using individually prescribed coloured filters. Data from 323 consecutive patients seen over a 15 month period in an optometric clinic specialising in SpLD are reviewed. Visual symptoms and headaches were common. 48% of patients were given a conventional optometric intervention (spectacles, orthoptic exercises) and 50% were issued with coloured filters, usually for a trial period. 40% of those who were given orthoptic exercises were later issued with coloured overlays. 32% of those who were issued with coloured overlays were ultimately prescribed Precision Tinted lenses. Approximately half the sample were telephoned more than a year after the last clinical appointment. More than 70% of those who were prescribed Precision Tints were still wearing them daily, and results for this intervention compared favourably with data for non-tinted spectacles. The data suggest that many people with SpLD need optometric care and that the optometrist needs to be skilled in orthoptic techniques and cognisant of recent research on coloured filters.
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PMID:A review of the management of 323 consecutive patients seen in a specific learning difficulties clinic. 1076 28

The primary aim of this project was to study the effect of flip lens-training on the accommodative function in a group of children with accommodative dysfunction and subjective symptoms such as asthenopia, headache, blurred vision, and avoidance of near activity. We also wanted to measure the accommodative facility among the children in comparison with a control group. Another aim of the study was whether flip lens-training increased accommodative facility, and to find out if it also had a positive effect on their asthenopia and related problems also in long term. Following the training period the accommodative facility and accommodative function significantly increased and two years after finishing the training period no child had regained any subjective symptoms and the objective findings were almost the same as at the end of facility training period. These results suggest that accommodative facility training is an efficient method built on loss of symptoms among children with accommodative infacility.
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PMID:Accommodative facility training with a long term follow up in a sample of school aged children showing accommodative dysfunction. 1094 12

In a multicenter, randomized, double-blind, cross-over study in the Netherlands, the effectiveness of (prism-)glasses prescribed by the Measurement and Correction Method of H.-J. Haase (MKH) was compared to that of glasses prescribed by conventional orthoptic examination. Nine pairs of MKH-optometrists and orthoptists recruited patients who primarily presented with asthenopia, and each prescribed the patient (prism-)glasses. A questionnaire for asthenopia was developed that rated headache and tired eyes as 0-7 days per week and none-light-medium-severe, respectively. Light sensitivity, problems with focusing, near-work problems and burning eyes were each rated as: never-occasionally-often-always. A patient was eligible if he scored 'medium', 'often' or '5 days a week' twice; or 'medium' (etc.) once and 'light' (etc.) twice. Controls, in contrast to the patients, typically answered 'none' or 'never' to half of the complaints, but 37% of them would have passed the admission criteria. Among other criteria were: 18 to 40 years of age, horizontal angle < 4 degrees, vertical < 1.7 degrees, acuity > or = 0.8, stereopsis threshold disparity < 120". Seventy-two patients fulfilled all criteria and returned sufficient questionnaires. They wore the first glasses for six weeks, were without glasses for two weeks, and then wore the second glasses for six weeks. At the start, halfway and at the end of each 6-week period, questionnaires were filled out; 97% were returned. Only 19 of the orthoptists' glasses contained prisms (14 horizontal, 5 vertical; horizontal average of all glasses 0.49 PD, vertical 0.05 PD). Five of the orthoptists' glasses were plano. All MKH glasses contained prisms, 53 of 72 both horizontal and vertical, 18 only horizontal and one only vertical (horizontal average of all glasses 2.83 PD, vertical 0.79 PD). The starting levels of complaints were high and both glasses improved complaints dramatically. The starting levels were lower, but not significantly, in the second 6-week period and improvement was less outspoken. Because of these differences, the two periods had to be evaluated separately. The primary outcome of the study was defined as the difference between the effect of the MKH glasses and that of the orthoptists' glasses in the first and second 6-week periods. For problems with focusing, in the first 6-week period, and for tired eyes, in the second 6-week period, the difference exceeded the difference that had been defined as clinically significant (one day per week less headache or half the distance light-medium or half the distance occasionally-often), but it did not reach statistical significance. The statistical power was approximately 0.7 for demonstrating this clinically significant difference. Statistical significance was not reached in multivariate repeated measure ANOVA either. Forty-four patients preferred to keep the MKH glasses, 25 the orthoptists' glasses, including one plano. It is striking that 25% of the patients did not prefer the glasses that, according to the questionnaire, improved their complaints the most. A year after the study, the questionnaire was sent again to all patients: The levels of complaints after a year were similar to those at the end of the second 6-week period, whether they had preferred the MKH or the orthoptists' glasses, and were similar to the levels in controls. The most conspicuous finding was that both glasses improved the complaints dramatically. Apart from the prisms, other reasons could be: spherical and cylindrical correction, improved wearing comfort of the frame, placebo effect, Hawthorne effect and regression to the mean.
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PMID:Preliminary report: prescription of prism-glasses by the Measurement and Correction Method of H.-J. Haase or by conventional orthoptic examination: a multicenter, randomized, double-blind, cross-over study. 1126 97

This study sought to experimentally validate two reported precipitants of chronic headaches, namely, negative affect (anxiety, anger, depression) and visual disturbance (flicker, glare, eyestrain), and to investigate whether they triggered common or different physiological mechanisms. Twenty-two male and 68 female subjects (46 with migraine, 29 with tension-type headache, and 15 controls) were submitted to antecedent challenges in the laboratory which induced negative affect or visual disturbance and to a control challenge. The results demonstrated that negative affect and visual disturbance can indeed precipitate headaches, and that the physiological responses associated with these antecedents differ, but the findings were not conclusive as to whether one or more physiological mechanisms are operative. Follow-up revealed that the antecedent challenges had significant effects on headache activity 48 to 72 hours after termination.
Headache
PMID:Effects of visual stimuli and a stressor on head pain. 1127 46

This study tested two contrasting theories of how trigger factors acquire the capacity to precipitate headaches. The sample consisted of 110 participants, of whom 48 suffered from regular headaches. Participants were exposed to a validated headache trigger factor for one of five exposure durations. The trigger used was "visual disturbance" (flicker, glare and eyestrain) induced by a very bright, stroboscopic light. Response to the stimulus was measured by participant ratings of the degree of visual disturbance and head pain caused by the stimulus. As expected, the headache sufferers experienced more visual disturbance and head pain in response to the stimulus than the non-headache individuals. Longer exposure to the stimulus was associated with a subsequent reduction in pain ratings in response to the stimulus. This desensitization effect supported an avoidance model of how trigger factors acquire the capacity to precipitate headaches. The findings of this study have implications for the etiology of headache disorders. Also, the findings imply that the traditional clinical advice that the best way to prevent migraine and headache is to avoid the factors that trigger them, may be counterproductive, as any short-term gains may be more than wiped out by decreased tolerance for the trigger factors.
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PMID:How do trigger factors acquire the capacity to precipitate headaches? 1134 Dec 51

The first electrophysiological study of the human lateral geniculate nucleus (LGN), optic radiation, striate, and extrastriate visual areas is presented in the context of presurgical evaluation of three epileptic patients (Patients 1, 2, and 3). Visual-evoked potentials to pattern reversal and face presentation were recorded with depth intracranial electrodes implanted stereotactically. For Patient 1, electrode anatomical registration, structural magnetic resonance imaging, and electrophysiological responses confirmed the location of two contacts in the geniculate body and one in the optic radiation. The first responses peaked approximately 40 milliseconds in the LGN in Patient 1 and 60 milliseconds in the V1/V2 complex in Patients 2 and 3. Moreover, steady state visual-evoked potentials evoked by the unperceived but commonly experienced video-screen flicker were recorded in the LGN, optic radiation, and V1/V2 visual areas. This study provides topographic and temporal propagation characteristics of steady state visual-evoked potentials along human visual pathways. We discuss the possible relationship between the oscillating signal recorded in subcortical and cortical areas and the electroencephalogram abnormalities observed in patients suffering from photosensitive epilepsy, particularly video-game epilepsy. The consequences of high temporal frequency visual stimuli delivered by ubiquitous video screens on epilepsy, headaches, and eyestrain must be considered.
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PMID:Human lateral geniculate nucleus and visual cortex respond to screen flicker. 1250 50

The aim of this work was to study the relation between subjective symptoms at near and ocular accommodation in terms of the amplitude of accommodation and the relative accommodation. A secondary aim was to discuss the diagnosis of accommodative insufficiency. The chosen cohort was examined on two occasions with 1.8 years in between. The first examination included 72 children, 43 boys (mean age 8.1 years, ranging from 5.8 to 9.8) and 29 girls (mean age 8.3 years, ranging from 6.2 to 10.0). The second examination included 59 of these children, 34 boys (mean age 9.9 years, ranging from 7.8 to 11.7) and 25 girls (mean age 10.1 ranging from 8.0 to 11.8). Subjective symptoms at near work (headache, asthenopia, floating text, facility problems) were recorded and the amplitude and the relative accommodation, both positive and negative, were measured. The result from the questionnaire showed that at the first examination more than one-third of the children (34.7%) reported at least one subjective symptom when doing near work and 42.4% at the second examination. No symptoms were found among children younger than 7.5 years, but for children between 7.5 and 10 years old at the first examination, the prevalence of at least one symptom was 47.2%. At the second examination, symptoms were reported also for the youngest children, i.e. from the age of 8 years. The discrimination ability for the amplitude of accommodation, both monocular and binocular, was significant. In the first examination the difference between the mean for the two groups (i.e. with and without at least one symptom) was around 2.00 D monocular and 3.00 D binocular. Corresponding figures from the second examination was a difference between the mean for the two groups of around 3.50 D monocular and nearly 4.00 D binocular. We suggest that accommodation measurements should be performed more routinely and regularly, maybe as screening, especially in children over 8 years of age.
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PMID:Accommodation and the relationship to subjective symptoms with near work for young school children. 1646 Mar 15


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