TL;DR: Findings support the idea that the pathogenesis of migraine is related to an imbalance in activity between brain stem nuclei regulating antinociception and vascular control.
Abstract: Evidence from animal experiments shows that the brain stem is involved in the pathophysiology of migraine. To investigate human migraine, we used positron emission tomography to examine the changes in regional cerebral blood flow as an index of neuronal activity in the human brain during spontaneous migraine attacks. During the attacks, increased blood flow was found in the cerebral hemispheres in cingulate, auditory and visual association cortices and in the brain stem. However, only the brain stem activation persisted after the injection of sumatriptan had induced complete relief from headache and phono- and photophobia. These findings support the idea that the pathogenesis of migraine is related to an imbalance in activity between brain stem nuclei regulating antinociception and vascular control.
TL;DR: GO affected females six times more frequently than males (86% versus 14% of cases, respectively) and the peak incidence rates were bimodal, occurring in the age groups 40 to 44 years and 60 to 64 years in females and 45 to 49 years and 65 to 69 years in males.
Abstract: Among incident cases of GO in Olmsted County, Minnesota: GO affected females six times more frequently than males (86% versus 14% of cases, respectively). The age-adjusted incidence rate was 16 cases per 100,000 population per year for females and 2.9 cases per 100,000 population for males. The peak incidence rates were bimodal, occurring in the age groups 40 to 44 years and 60 to 64 years in females and 45 to 49 years and 65 to 69 years in males. Among patients with GO, approximately 90% had Graves' hyperthyroidism, 1% had primary hypothyroidism, 3% had Hashimoto's thyroiditis, and 5% were euthyroid. Eyelid retraction was the most common ophthalmic feature of autoimmune thyroid disease, being present either unilaterally or bilaterally in more than 90% of patients at some point in their clinical course. Exophthalmos of one or both eyes affected approximately 60% of patients, restrictive extraocular myopathy was apparent in about 40% of patients, and optic nerve dysfunction occurred in either one or both eyes in 6% of patients with autoimmune thyroid disease. Only 5% of patients had the complete constellation of classic findings: eyelid retraction, exophthalmos, optic nerve dysfunction, extraocular muscle involvement, and hyperthyroidism. Upper eyelid retraction, either unilateral or bilateral, was documented in approximately 75% of patients at the time of diagnosis of GO. Lid lag also was a frequent early sign, being present either unilaterally or bilaterally in 50% of patients at the initial examination. At the time of diagnosis of GO, the most frequent ocular symptom was pain or discomfort, which affected 30% of patients. Some degree of diplopia was noted by approximately 17% of patients, lacrimation or photophobia was present in about 15% to 20% of patients, and 7.5% of patients complained of blurred vision. Decreased vision attributable to optic neuropathy was present in less than 2% of eyes at the time of diagnosis of GO. Thyroid dermopathy and acropachy accompanied GO in approximately 4% and 1% of patients, respectively. Myasthenia gravis occurred in less than 1% of patients. Superior limbic keratoconjunctivitis was documented in less than 4% of patients. The median age at the time of diagnosis of GO was 43 years (range, 8 to 88). Among patients with hyperthyroidism, 61% developed ophthalmopathy within 1 year of the onset of thyrotoxicosis. Symptoms and signs for which statistically significant changes occurred between the initial and final examinations included lacrimation, pain or ocular discomfort, photophobia, eyelid retraction, lid lag, eyelid fullness, conjunctival injection, chemosis, and exophthalmos.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: Both migraine and vertigo are common in the general population with lifetime prevalences of about 16 % for migraine and 7 % for vertigo, but recent epidemiological evidence suggests that the actual comorbidity is higher than previously thought.
Abstract: Both migraine and vertigo are common in the general population with lifetime prevalences of about 16 % for migraine and 7 % for vertigo. Therefore, a concurrence of the two conditions can be expected in about 1.1 % of the general population by chance alone. However, recent epidemiological evidence suggests that the actual comorbidity is higher, namely 3.2 %. This can be explained by the fact that several dizziness and vertigo syndromes occur more frequently in migraineurs than in controls including benign paroxysmal positional vertigo, Meniere's disease, motion sickness, cerebellar disorders and anxiety syndromes which may present with dizziness. In addition, there is increasing recognition of a syndrome called vestibular migraine (VM), which is vertigo directly caused by migraine. VM affects more than 1 % of the general population, about 10 % of patients in dizziness clinics and at least 9 % of patients in migraine clinics.Clinically, VM presents with attacks of spontaneous or positional vertigo lasting seconds to days. Migrainous accompaniments such as headache, phonophobia, photophobia or auras are common but not mandatory. Cochlear symptoms may be associated but are mostly mild and non-progressive. During acute attacks one may find central spontaneous or positional nystagmus and, less commonly, unilateral vestibular hypofunction. In the symptom-free interval, vestibular testing adds little to the diagnosis as findings are mostly minor and non-specific. In the absence of controlled studies, treatment of VM is adopted from the migraine sphere comprising avoidance of triggers, stress management as well as pharmacotherapy for acute attacks and prophylaxis.
TL;DR: The clinical characteristics and disorders associated with photophobia are reviewed, the anatomy and physiology of this phenomenon are discussed, and a practical approach to diagnosis and treatment is concluded.
Abstract: Photophobia is a common yet debilitating symptom seen in many ophthalmic and neurologic disorders. Despite its prevalence, it is poorly understood and difficult to treat. However, the past few years have seen significant advances in our understanding of this symptom. We review the clinical characteristics and disorders associated with photophobia, discuss the anatomy and physiology of this phenomenon, and conclude with a practical approach to diagnosis and treatment.
TL;DR: There is a clear association between the head pain and the release of the neuropeptide calcitonin gene-related peptide (CGRP) from the trigeminovascular system, and a central role for sensory and parasympathetic mechanisms in the pathophysiology of primary headaches.