Discussion
Activity-related headaches can be brought on by Valsalva maneuvers (“cough headache”) or prolonged exercise (“exertional headache”). These headaches account overall for 1-2% of the consultations due to headache in a general neurological Department for adults
[
9], while in children they are very rare. These entities are a challenging diagnostic problem as they can be primary or secondary and as their etiologies differ depending on the headache pattern
[
9].
Primary cough headache (PCH) is considered to be a rare condition, accounting for 0.4% of all headaches consulting a Neurology Department, and predominantly affects male patients older than 40 years of age
[
4,
5,
9‐
11]; its pathophysiology is unknown
[
4,
5,
9‐
11]. PCH is a sudden-onset headache that usually lasts from 1 second to 30 minutes, tends to be bilateral and posterior, is brought on by and occurring only in association with coughing, straining and/or Valsalva maneuver, and it responds to indomethacin
[
4,
5,
9‐
14]. A craniocervical MRI study is mandatory to rule out posterior fossa lesions
[
5,
9]; in fact cough headache can be symptomatic in about 40% of cases and the large majority of them are due to CM1 [4,5,9-11], as in case 2 of the present study. Other reported causes of symptomatic cough headache include carotid or vertebrobasilar diseases and cerebral aneurysms. Differently from PCH, secondary cough headache begins earlier (average 40 vs 60 years), is located posteriorly, lasts longer (years vs months), is associated with posterior fossa signs or symptoms, and does not respond to indomethacin
[
9,
10].
Among the 72 cases with activity-related headaches described by Pascual
et al.
[
5] there were 30 patients with cough headache (13 primary, 17 secondary) and 28 cases with exertional headache (16 primary; 12 secondary); the few cases (the exact number was not specified) under the age of 18 years had secondary cough headache or primary exertional headache. Age at onset of secondary cough headache (mean 39 ± 14, range 15 - 63) was significantly lower than for PCH (mean 67 ± 11, range 44 - 81). All cases with secondary cough headache had a CM1, and most of them (14/17) complained posterior fossa symptoms or signs apart from headache; the three patients having isolated headache developed posterior fossa symptoms or signs after an interval between 1 to 5 years
[
5].
In our two cases we investigated whether the pattern of headache met the diagnostic criteria of ICHD-II
[
1]. In presence of cough headache, that both our patients presented, the criteria A-B-C of PCH (4.2, ICHD-II)
[
1] are satisfied, but the diagnosis requires that headache is not attributed to an another disorder. In fact in our cases, by mean of brain MRI showing respectively a cerebellar neoplasm (case 1) and a CM1 (case 2), a diagnosis of secondary cough headache could be made. Considering other possible encodings, case 1 met all the criteria for headache attributed to intracranial neoplasm (7.4.2, ICHD-II)
[
1]. Moreover the child had an isolated episode of paroxysmal torticollis, lasting about two hours, that was a strong element of suspicion for craniocervical pathology. Case 2 fulfilled the criteria A, B and D for headache attributed to CM1 (7.7, ICHD-II)
[
1], while criteria C was only partially satisfied. This is probably due to the fact that the young age of child made difficult to refer and therefore to recognize transient visual or oto-neurological symptoms
[
15‐
19]; moreover the follow-up was not long enough to establish if the patient will develop posterior fossa symptoms or signs within 5 years, as reported in the study by Pascual
et al.
[
5].
In our two cases headache was triggered not only by cough but also by exertion, therefore we considered another diagnostic category, exertional headache.
Primary exertional headache (PEH) can present in adolescence
[
6‐
8], last more than 5 minutes and is often associated with disautonomic symptoms. Among 72 cases with activity-related headaches, primary exertional headache (age: 24±11, 10-48) began significantly earlier than PCH and secondary exertional headache
[
5]. On first occurrence of this headache type, it is mandatory to exclude subarachnoid haemorrhage and arterial dissection
[
6‐
8,
12,
14].
While in PCH the headache can be triggered by exercise or by coughing, in the PEH pain occur only during or after physical exertion
[
1,
6‐
8]. Therefore in our cases headache pattern did not meet the criteria for PEH because in both cases headache was triggered by exertion and coughing, and in case 1 the duration of pain was much lower than 5 minutes.
A type of headache where the pain is described as a pinch or a stab and it is short lasting, as in our cases, is primary stabbing headache (4.1, ICHD-II)
[
1]. It is characterized by transient and localised stabs of pain, single or serial, that occur spontaneously in the absence of organic disease of underlying structures. Case 1 met all the criteria but one, in which the pain is felt in the distribution of the first division of the trigeminal nerve.
Considering the duration of headache in our two cases, also short lasting headaches can be included in the differential diagnosis, in particular for case 1 that initially had short lasting attacks not triggered by Valsalva maneuver.
Short lasting headaches include short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), primary stabbing headache, cluster headache, paroxysmal hemicrania, and neck-tongue syndrome
[
1,
20‐
25].
SUNCT is classified among primary headaches and it is characterized by short-lasting attacks (from 5 seconds to 4 minutes) of unilateral pain that are much briefer than those seen in any other trigeminal autonomic cephalalgias and very often accompanied by prominent lacrimation and redness of the ipsilateral eye (3.3, ICHD-II)
[
1]. SUNCT is a very rare syndrome, particularly in childhood
[
20‐
22].
Primary stabbing “ice-pick” headache is a primary headache syndrome characterized by transient, sharp, stabbing pains that occur within a small area of the scalp for seconds
[
23]. The pain tends to occur in the distribution of the first division of the trigeminal nerve, including the orbital, temporal, or parietal regions
[
23]. Its prevalence in children is estimated at 3-5% and it usually appears by age 10 years
[
23]. In a large sample of children affected, this type of headache usually was not associated with other primary headache syndromes
[
24].
Cluster headache (3.1, ICHD-II)
[
1], that affects adults, consists of strictly unilateral pain attacks, more frequent (1-8 times a day), longer (15-180 minutes) and associated with ipsilateral autonomic symptoms
[
25]; therefore it can be excluded in our cases. The same applies to paroxysmal hemicrania (3.2, ICHD-II)
[
1] that is a rare condition, particular in children, similar to cluster headache but with shorter duration (2-30 minutes) and higher frequency (> 5 times a day).
Neck-tongue syndrome (13.9, ICHD-II)
[
1] consists of a sudden onset of pain in the occipital region or upper neck, associated with abnormal sensation in the same side of the tongue; in our cases one of the three criteria (pain is commonly precipitated by sudden turning of the head) was not satisfied.
In the literature there are no reports on cough headache in children younger than 10 years. In our cases, the clinical elements of suspicion for a secondary headache were the pain caused by the Valsalva maneuver (strain/cough) for both and, in case 1, the recent onset of headache, the nuchal site of pain, an episode of vomiting without headache and stiff neck, while in case 2 the low age of onset (3 years). Our cases demonstrate that midline lesions in young children do not lateralize well on neurological examination. Therefore, recurrent or progressive headache without the other associated features of migraine should be alarming enough to obtain neuroimaging.
In adults almost half of cases (42%) with activity-related headaches had intracranial lesions, and symptomatic cases (57%) prevailed among subjects with cough headaches
[
5]. This also can be applied to children in which the prevalence, not estimated, of primary cough and exertional headaches is likely to be rarer than in adults.
The association with strain or a cough is therefore an important clinical issue, which should always be investigated and that can be a sign of alarm for secondary headaches, especially in children.
When headache has a recent onset, it presents suddenly, it is triggered by strain, even with normal neurological examination, neuroimaging is mandatory in order to exclude secondary headaches, particularly in children. An early clinical diagnosis allowed in our cases a good control of underlying disease.
Consent
Written informed consent was obtained from the patients’ parents for the publication of the cases report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
Ethical approval
The clinical management of the patients reported in this paper was conform to the indications provided by our institutional review board.
Competing interests
The authors declare no potential conflicts of interests with respect to the authorship and/or publication of this article.
Authors’ contributions
IT, DDC, LDP, RM: have made substantial contributions to conception and design, acquisition of data, analysis and interpretation of data; MG, BB, MN, LB: have been involved in drafting the manuscript; IT, SS, PAB: were involved in revising the manuscript critically for important intellectual content and have given final approval of the version to be published. All authors read and approved the final manuscript.