Frequency of diagnoses in a specialized headache clinic in Buenos Aires Frequência de Diagnósticos em um Centro de Cefaleia Especializado de Buenos Aires

DOI: 10.5935/2178-7468.20190002 Objective: Headache is one of the most frequent reason for consultations in neurology. The global prevalence among adults with migraine is approximately 10% with migraine, 40% for tension-type headache (TTH) and 3% for chronic daily headache. The purpose of this study is to analyze the prevalence of the diagnoses of headache and craniofacial pain among patients evaluated in a specialized headache clinic of Buenos Aires during 2017. Methods: Retrospective, descriptive study. We reviewed the electronic medical records of patients who consulted for headaches or craniofacial pain from January 1st to December 31st, 2017. Diagnoses were made according to the criteria of the International Classification of Headache Disorders (ICHD-3). Results: We reviewed 3254 electronic medical records and documented 3941 diagnoses: headache (93.03%), craniofacial pain (3.62%) and unclassifiable (3.35%). The average age was 43.14 years. 80.7% were women. Primary headaches were the most frequent diagnoses (78.54%). Migraine represented the main diagnosis (87.42%). Episodic migraine without aura was the most prevalent diagnosis (48%). Tensiontype headache (TTH) was found in 8.74% of cases of primary headaches and Trigeminal autonomic cephalalgias (TACs) in 2.89%. Medication-overuse headache (MOH) represented 77.93% of the secondary headaches, and most of them also met chronic migraine criteria fulfilled criteria of chronic migraine. Primary trigeminal neuralgia represented 50% of craniofacial pain and 27% were secondary trigeminal neuralgia, mostly postherpetic or posterior to dental procedures. Regardin to the frecuency, 33.58% of the patients had chronic headache. Conclusion: In our section, migraine is the most frequent diagnosis followed by medication-overuse headache. The percentage of chronic headache is higher than the prevalence in the general population, probably because it is a tertiary center.


INTRODUCTION
Headache is one of the most frequent consultations in neurology. It is estimated that 95% of men and 99% of women will have at least one episode of headache throughout their life, provided that about 40% have it quite regularly. 1 The global prevalence among adults is apporxiamtely 10% of migraine, 40% for tension-type headache (TTH) and 3% for chronic daily headache . 2 In general population the most frequent headache is TTH, but among patients visiting specialized clinics migraine is the first diagnosis.
Headache can have a significant impact on the patients quality of life. On the World Health Organization's ranking of causes of disability, headache disorders are between the 10 most disabling conditions for the two genders, and between the five most disabling for women. 2 There are few data about frequency of headache and craniofacial pain in South America. The purpose of this study is to analyse the prevalence of the diagnoses of headache and craniofacial pain among patients evaluated in Fleni, a specialized headaches clinic of Buenos Aires, during 2017.

Patients and methods
We performed a retrospective, descriptive study based on the electronic medical records of patients evaluated for headaches or craniofacial pain who presented to the headache clinic of the Fleni Institute from January 1 sth to December 31 sth , 2017. Diagnoses were recorded according to the International Classification of Headache Disorders (ICHD-3) criteria. When a patient met criteria for more than one type of headache, all of them were coded. This work was approved by the ethics committee of the Fleni Institute.

DISCUSSION
The demographic characteristics of the study showed a female-to-male ratio of 4:18, higher than in other published series 3 . Average age of the patients was 43.14 years, comparable with those reported previously 3 .
As in other specialized headache, the most frequent diagnosis in our population was migraine. Among them, episodic migraine without aura was the most prevalent, followed by chronic migraine and finally migraine with aura.
The second diagnosis was Medication-overuse headache. All these patients also have another type of headache, which was the cause that leaded to the abuse of analgesics. These patients were mostly diagnosed with chronic migraine without aura.
Tension headache was the next diagnosis in frequency. Although this type of headache is the most frequent in the general population, the percentage is lower in specialized centers, because it usually generates less impact on the patients live, and therefore, they need less medical assistance. In our series the prevalence of this type of headache is lower than in other published studies. Cluster headache was the most frequent trigeminal autonomic cephalalgia. Other primary headaches accounted a small percentage of the diagnoses.
Medication-overuse headache was the most frequent secondary headache. The majority were patients with chronic migraine. The next diagnosis within this group was headache associated with craniofacial and/or cervical pathologies, mainly cervicogenic pathology and temporomandibular joint.
Within craniofacial neuropathic pain, primary trigeminal neuralgia was the most prevalent, while postherpetic neuralgia was the next frequency diagnosis.
The percentage of chronic headaches was 34%, higher than in the general population, probably because Fleni is a tertiary center. Most of them were migraines.

CONCLUSIONS
There are few published data about frequency of different types of headaches and craniofacial pain in South America, being the main data those coming from Brazil. [4][5][6] According to our knowledge there are no data from Argentine headache center In our section, migraine is the most frequent headache. Unlike the published data, where tension-type headache is the next cause of consultation in specialized centers, medication-overuse headache is the second diagnosis. The percentage of chronic headache is higher than the prevalence in the community, probably because it is a tertiary center.
The high frequency of chronic headache , especially Medication-overuse headache highlight the need for more education for doctors and the importance of raising awareness among patients about its prevention, detection and treatment.