Headache prevalence in the population of L’Aquila (Italy) after the 2009 earthquake

The large majority of primary headache in patients afferent to ER are of essential origin. In fact, up to 90% of patients suffering from headache are affected by the TTH or by migraine [4]. The peculiar clinical context of the present observational study may provide some interesting clues. The population study was stratified by gender and age according to the epidemiological studies on primary headache reported in the literature [5]. The different types of primary headache were distributed according to the prevalence observed in the general population [6]. However, a substantial increment up to 70% of TTH forms was observed when compared with the 11% migraine and 20% remaining types (cluster, trigeminal, etc.). Secondary forms represented only 2.82% of the total, and were correctly diagnosed on the basis of the reported questionnaire and the accurate observation of the associated symptoms; obviously, these cases required a different therapeutic approach when compared with primary headache. The prevalence of primary headache was high, reaching a 16% of all post-seismic painful pathologies; also in relation to pathologies of other origin, primary headache represented the 5.53% of all causes of access to AMPs within the 5 weeks of the study. The shortage of diagnostic tools, including routine chemistry and imaging techniques, did not prevent a correct diagnosis of primary conditions that was mostly based on the exhaustive differential diagnosis. During a natural disasters, the clinical presentation of headache is super imposable in most of the cases; symptoms may be associated or masked by multiple external factors, including fasting, dehydratation, insomnia or panic. Overall, headache episodes may be induced by the stress related to the catastrophic event. A stressful event, indeed, has been shown to precipitate a pain episode of TTH or migraine [7]. It has been hypothesized that a chronicizing stress, poor stress tolerance, prolonged physiological response to stressors or insufficient recovery from stress can cause headache, chronic pain and multiple physical disturbances [8]. These factors support the observations of the present study. Several stress-related factors may have induced or worsened the episodes of headache. First of all, the uncomfortable life conditions, including living in tents, atmospheric agents, high temperature excursion (hot days, wintry nights and/or rain), small uncomfortable beds, hard physical work in order to meet personal and community daily life needs in the emergency centers. A drastic interruption of domestic and social habits as a consequence of the catastrophic event caused a deep sense of impotence and limitation of autonomy that seriously influenced individual and community mood [9]. The time course and distribution of cases during the 5-week observation period shows that inadequate adaptation to multiple acute stressors directly or indirectly related to disaster played a key role in inducing headache episodes. The increased prevalence of primary headache, indeed, during 3 weeks after the earthquake may be related to the stress of the acute event and the associated factors including psycho-physical changes of individuals, due to acceptance, hope, resignation or other factors such as progressive improvement of social, hygienic and structural conditions and decreased intensity of the seismic swarm.

The high frequency of first episodes of primary headache is another distinctive element that underlines the importance of chronicizing stress in the pathogenesis of this condition. The “central” mechanisms of the disease may have been triggered off, in particular, by peripheral mechanisms such as contraction, hypersensitivity, pain of pericranial and cervical muscles, secondary to the above-mentioned hard life context. Overall, these elements may be responsible for increase of chronic forms after the catastrophic event [10]. Several studies, indeed, have shown that activation of muscles of the pericranial areas related to pain may be induced directly by stress or by modulation of specific nociceptive afferences related to episodes of central sensitisation. In fact, central sensitisation is recognized as an important mechanism in the pathogenesis of primary headache, either TTH or migraine [11‐13]. In the presence of a natural disaster, the relationship between stress and pain may perpetuate a dangerous vicious circle. The physiopathological mechanisms of headache may have amplified the role of the stressful event in cases exposed and stress, in turn, may have enhanced the relapse and/or appearance of pain. This vicious circle should be blocked also in emergency situations by the administration of effective analgesic drugs, in order to prevent pain chronicization, in particular, in post-traumatic cases. In the present study, drugs most frequently administered as pain relievers included paracetamol (36%) and non-steroid antiinflammatory drugs (46%); weak opioids (18%), either alone or associated with paracetamol were used in a smaller percentage of cases. The high intensity of pain (average NRS score 7 ± 1.1, severe pain) in the acute phase of headache often required a strict monitoring of vital parameters [BP, HR, BT (in °C), SpO₂] and of the analgesic effect of drugs by the NRS score during the following 2 h. The decrease of pain intensity as assessed by the difference between NRS scores was the reference parameter for estimating the efficacy of drugs either immediately (T_2h = first 2 h) as in the following 24–48 h (T_24h and T_48h). It is known that about two-third of patients complain new episodes of pain within 24 h after discharge from ER; in half of them, the intensity of pain is mild-severe [14]. Up to 50% of patients report a functional disability within 24 h after the headache crisis causing the access to the ER [15]. In the present study, 77% of patients required the administration of analgesic drugs up to 48 h after the onset of the crisis in order to control pain. This suggests that the mechanisms triggering and maintaining headache were operating for a longer period than the stress-induced peripheral and muscular mechanisms usually do. An early treatment, although with the limited number of drugs available, and a strict monitoring of patients, allowed us to substantially control pain, as shown by the decrease of the average NRS scores within 48 h (T_48h = 1.8 ± 0.68). Figures 1, 2, 3 shows the time course of pain during the observation period. The choice of the drug, in the large majority of cases NSAIDs or paracetamol, according to medical history and characteristic of pain, was mostly influenced by the shortage of specific drugs, such as triptans [16], ergot derivatives [17], antiepileptic drugs [18], and narcotic analgesics [19]. Analgesic drugs have been mainly administered orally; the oral route facilitated the therapeutic management of patients after discharge and improved their compliance to treatment during the following 48 h.