8: Migraine

Case 8 Migraine



Description of migraine




Epidemiology


Migraine typically begins in adolescence. The prevalence of the condition increases from this point, peaking around age 40 and declining thereafter. In the US, migraine affects around eighteen per cent of women and six per cent of men.3 The higher prevalence rate reported in the female population is evident across all age groups, except for the prepubescent period, in which migraine is relatively more common in males. Migraine is also more prevalent among Caucasians, particularly Europeans and Americans; it is least prevalent in the African and Asian populations.3



Aetiology and pathophysiology


The aetiology and pathophysiology of migraine are complex and still not completely understood. Genetic predisposition is likely to be a contributing factor, although not all cases have a familial tendency.4 Even though specific causes of migraine have yet to be established, a number of triggers have been identified. Intrinsic triggers, such as oestrogen fluctuation, brain serotonin depletion, temporomandibular joint dysfunction, emotional stress, excessive or inadequate sleep and neck pain, as well as extrinsic triggers such as tyramine-containing foods (i.e. cheese, red wine, chocolate, preserved meats), monosodium glutamate, weather changes (such as increased temperature or elevated barometric pressure), head trauma, hormone therapy, oral contraceptive use, strong odours, intense or flashing light and skipped meals, have all been associated with the onset of migraine.1,2,5 It is also suggested that nutritional deficiency, specifically, magnesium deficiency, could play a role in the pathogenesis of migraine.68


Genetic predisposition and/or risk factors as yet unknown may lower an individual’s threshold to these triggers, upon exposure to which, susceptible individuals may experience a reduction in cerebral blood flow, which, in some people, may manifest as an aura. The cortical spreading depression (CSD) of blood flow from the occipital lobe to other regions of the cerebral cortex, which may be preceded by brain serotonin depletion, triggers the diffuse activation of perivascular trigeminal sensory nerves.5 These impulses are transmitted to the trigeminal nucleus caudalis of the brainstem and from there to the periaqueductal grey matter, sensory thalamus and sensory cortex. The stimulation of these regions results in the manifestation of pain.2,4


There are several deviations from this theory, however. Some argue that the pain of migraine is simply a rebound vasodilatatory response to CSD. Others propose that the activation of the trigeminovascular system increases neuropeptide release, which results in painful inflammation to the dura mater and cranial vessels.1 Still others have also indicated that migraine may be the result of mitochondrial dysfunction and a subsequent impairment in cellular oxygen metabolism.9 While researchers do not completely agree on the pathophysiology of migraine, there is general agreement that migraine is a neurovascular disorder.



Clinical manifestations


The International Headache Society (IHS) defines migraine as a repeated, episodic headache of 4–72 hours duration that is characterised by any two of the following: unilateral distribution, throbbing quality, moderate or severe intensity and/or worsened by movement. To complete the IHS criteria, the pain also should be accompanied by nausea and vomiting, or photophobia and phonophobia.4 It is not unusual for individuals with migraine to also experience osmophobia, poor concentration, blurred vision, clumsiness, localised weakness, numbness or tingling, irritability and scalp tenderness.1,2


In cases of classic migraine, the headache is preceded by a temporary neurological disturbance known as an aura. This phenomenon typically presents as a visual defect (e.g. bright zigzags, scintillating lights), but may also manifest as a sensory or motor disturbance (e.g. paraesthesias, dysarthria, ataxia, confusion).2 Hemiplegic migraine generally presents as unilateral weakness, and basilar artery migraine as focal weakness, vertigo, ataxia and altered consciousness.1 The symptoms of migraine are often aggravated by bright lights, noise, strong odours and physical activity, and are somewhat relieved following seclusion in a dark, quiet environment.1




Clinical case


35-year-old woman with classic migraine



Rapport


Adopt the practitioner strategies and behaviours highlighted in Table 2.1 (chapter 2) to improve client trust, communication and rapport, as well as the accuracy and comprehensiveness of the clinical assessment.





Medical history








Diagnostics


CAM practitioners can request, perform and/or interpret findings from a range of diagnostic tests in order to add valuable data to the pool of clinical information. While several investigations are pertinent to this case (as described below), the decision to use these tests should be considered alongside factors such as cost, convenience, comfort, turnaround time, access, practitioner competence and scope of practice, and history of previous investigations.



Pathology tests


Magnesium deficiency test

Magnesium deficiency may be implicated in the pathogenesis of migraine.68 Intracellular and/or extracellular magnesium concentration may be measured using a range of different specimens – hair, erythrocytes, serum, urine and faeces. While some authorities indicate that erythrocytic magnesium concentration may be more sensitive than other methods in measuring magnesium levels,10 there has been little rigorous research to substantiate this argument. In fact, studies suggest that hair magnesium may be a more sensitive measure of magnesium concentration than erythrocytic magnesium, and serum magnesium the least sensitive.11 Thus, assessing hair or erythrocytic magnesium concentration may help to determine whether magnesium deficiency is a contributing factor in this condition.









Application


The range of interventions reported in the CAM literature that may be used in the treatment of migraine are appraised below.



Diet


Low antigenic diet (Level II, Strength C, Direction + (for oligoantigenic diet only))

Tyramine-containing foods, such as cheese, red wine, chocolate and preserved meats, and food additives such as monosodium glutamate, are considered to be key dietary triggers of migraine headache.1,2 Even though many studies have explored the relationship between these triggers and the onset of migraine, the evidence is not convincing. Several dietary studies have, for instance, reported a large reduction in migraine frequency during the consumption of an oligoantigenic diet and the provocation of migraine attacks following double-blind challenges with suspected dietary triggers.1820 These findings should be considered with caution given the small size of the studies and the lack of corroborating evidence from larger trials.


Several controlled clinical trials have also demonstrated an increased incidence of migraine attacks following the consumption of low tyramine-containing red wine21 and aspartame22 when compared with controls, but many studies have failed to find a statistically significant difference in migraine frequency in groups receiving tyramine,23 chocolate24 or a low vasoactive amine diet25 when compared with controls. This is corroborated by findings from a systematic review of 10 RCTs exploring the relationship between oral ingestion of biogenic amines and food intolerance reactions.26 The discrepancies between these research findings and those reported in the professional literature need to be resolved to minimise clinician confusion about the best practice care of migraine.

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Jul 22, 2016 | Posted by in MANUAL THERAPIST | Comments Off on 8: Migraine

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