Headache in military service members with a history of mild traumatic brain injury: A cohort study of diagnosis and classification

Abstract

Introduction

Headaches after concussion are highly prevalent, relatively persistent and are being treated like primary headaches, especially migraine.

Methods

We studied all new patients seen between August 2008 and December 2009 assessed by a civilian headache specialist at the TBI Center at Womack Army Medical Center, Fort Bragg, NC. We report sample demographics, injuries and headache characteristics, including time from injury to headache onset, detailed descriptions and International Classification of Headache Disorders second edition primary headache diagnosis type.

Results

A total of 95 soldiers reported 166 headaches. The most common injury cited was a blast (53.7%). Most subjects (76.8%) recalled the onset of any headache within 7 days of injury. The most commonly diagnosed headache was a continuous type with migraine features (n = 31 (18.7%)), followed by chronic migraine (type 1.5.1, n = 14 (8.4%)), migraine with aura (type 1.2.1, n = 10 (6.0%)), hemicrania continua (type 4.7, n = 12 (7.2%)), chronic cluster (type 3.1.2, n = 6 (3.6%)) and headaches not otherwise classifiable (type 14.1, n = 5 (3.0%)) also present. The most clinically important was a continuous headache with migraine features.

Conclusion

We present a series of patients seen in a military treatment facility for headache diagnosis after concussion in whom we found migraine, as well as uncommon primary headache types, at frequencies that were much higher than expected.

Keywords

Traumatic brain injury military headache migraine chronic migraine diagnosis

Introduction

The wars in Iraq and Afghanistan and the surge in interest in sports concussion have produced basic and clinical research opportunities as well as guidelines for return to military duty (1,2) and athletic play (3). Many of these recommendations are based upon findings from physical examinations and psychological testing instruments that are used to measure the short- and long-term impacts of concussions. Specific tests for cognitive function (4 –6), balance (7), visual tracking (8) and personality and behavioral changes (9) have been used to document the natural history of mild traumatic brain injury (TBI) and to evaluate potential therapies (10). No specific scale or instrument has yet been created to track the course of headaches attributed to mild TBI. Some of this may be due to the reliance upon recall of events from the onset of headache to a clinical evaluation. Other challenges include concurrent non-cephalic injuries, the subjective nature of head pain, differing expressions and descriptive capabilities of individuals or groups and the level of knowledge of clinicians and investigators. Adding confusion to this is the use of terms such as “mild TBI” or “concussion”, which have been used in different papers and contexts without consistency. In this report, the term “concussion” will be used in accordance with the common language of the army (11) where mild TBI is used synonymously, although differences in outcome may associate with the different terms (12).

In the military (13) and all other environments, diagnosing post-traumatic headache (PTH) requires a well-executed history and physical examination, including accounting for differences in populations (14,15). Headaches after concussion are highly prevalent (16 –18), relatively persistent (19) and are usually treated based upon primary headache nosology (20 –22). Since the first publications describing military service-related headaches after concussion, the focus has been on prevalence (17,18), associations with other symptoms (22), relationships to post-traumatic stress disorder (PTSD) and other psychological complications (21,23) and treatment (24 –26). Attempts to classify headaches have resulted in descriptive groupings (27) and categorical proposals (28 –30) and have been hindered by the lack of a gold standard questionnaire. Ongoing research aims to clarify further the relationships between concussion and primary headache diagnosis, with the goal of determining whether extant therapies are adequate or new therapies need to be developed. Since migraine is the most prevalent type (15 –17,27,31), usual therapies have been reported, but randomized controlled trials have not.

In a preliminary report on PTH in soldiers seen at the Womack Army Medical Center (WAMC) TBI Clinic, we described the headaches of 25 patients with a focus on phenomenology and diagnosis in which multiple headaches might be described by a single individual, and where diagnostic criteria according to the International Classification of Headache Disorders second edition (ICHD-II) were applied to all headaches (32). In that report, it was noted that the most common headache type was a non-standard, non-classifiable continuous headache with migraine features, meeting the criteria for migraine without aura on at least half of the days of the month prior to initial appointment. In addition, unusual and uncommon headache types were described. This present paper extends those findings to a larger group of 95 patients.

Methods

Subject sample and clinical evaluations

The study population consisted of all new patients referred for headache evaluation to a civilian headache specialist (AGF) and seen consecutively at the then-named TBI Center at WAMC, Fort Bragg, NC, between August 2008 and December 2009. The current name of that clinic is the Concussion Care Clinic. All subjects were active-duty military personnel at the time of initial evaluation. The design was retrospective and observational. All data were confirmed by reviewing medical records (the Armed Forces Health Longitudinal Technology Application or AHLTA) and recorded on a questionnaire-based template that was created for the previous study (31) in order to maximize consistency.

All subjects were clinically diagnosed with concussion, defined as head injury associated with either brief loss or alteration of consciousness, and confirmed by record review. Specific details differentiating complete from partial loss of sensorium were not included, since confirmation was often not possible. Clinical data included: demographics of age, gender, education and rank; causes of injury; and history of pre-injury concussions and headache symptoms. Mean values are reported with their standard deviations.

Injury

Injuries were defined as those to which the soldier attributed symptoms, including blast if an explosion occurred at the time of injury. All other head injuries were categorized as “non-blast”, including less common civilian types, such as parachute jumps.

Headache onset

Time from patient-reported signature concussion to first clinic visit was recorded. Patients were asked to identify the injury to which they attributed the onset or worsening of headache(s) and the time between that concussion and the onset of each headache type. The time of headache onset after attributed trauma was reported on a seven-point scale (immediate, less than 1 day, within 7 days, less than 30 days, 1–3 months, 3–6 months and greater than 6 months).

Headache characteristics

Headache descriptions were recorded in detail at the time of initial face-to-face evaluation and were entered into a template containing language and “keywords” derived from the ICHD-II. Soldiers were asked to list the number (up to three) and characteristics of each headache experienced in the last month prior to evaluation. Continuous headache was described as never having any time during waking hours without headache. If any time during a day was headache free, they were coded to “non-continuous”. Only one continuous headache was coded and up to two non-continuous headaches were recorded. Symptom-specific questions were repeated for each headache, including: the time of onset in relationship to head injury; the location and area of pain; the character, severity (none: 0, mild: 1, moderate: 2, severe: 3) and duration; modifiers, including triggers for episodic headaches; factors of worsening or relief, including those for continuous headaches; and associations, including photophobia, phonophobia, nausea/vomiting, neck pain and symptoms of the eye and/or nose. Patients were also asked about warning signs or symptoms for episodic headache or worsening of baseline headache using verbal and pictorial descriptions including, but not limited to, classical migraine aura, such as fortification spectra and scintillating scotoma.

Headache diagnosis

Headache characteristics were then codified for assigning criteria to the ICHD-II primary headache diagnosis “type” that were in use at the time of evaluation. Chronic PTH attributed to mild head injury (5.2.2) was not listed, as it was considered to be the primary clinical diagnosis. Secondary headaches were confirmed and coded. The most clinically important headaches were determined by the patient and the authors for the purposes of creating larger categories.

A false category, 2.3/1.x, was created for patients who described a headache type that was continuous which: (1) at baseline did not meet the criteria for tension-type headache because of an inclusive and regular migraine criterion; or (2) when worse, would attain other features and meet the criteria for migraine without aura. This category was created since this was the most commonly reported headache using verbal and visual cuing (e.g. a single headache that was continuous, but with migraine features, especially on more than 15 days in the previous month) (2.3/1.5.1), which we titled continuous headache chronic migraine (CHCM). (Note that the diagnosis of Hemicrania Continua (HC) was treated according to the International Classification of Headache Disorders – III (beta) (ICHD-III), which moved HC to the trigeminal autonomic cephalalgia (TAC).)

Diagnostic categories

All individual headaches were grouped according to the four major categories of primary headaches listed in the ICHD-II, and frequencies were recorded for each. We then grouped patients according to most clinically important headache regardless of total number of headaches described ad hoc by the clinician at the time of data recording and based upon the record review. This grouping of patients by the clinically most important of the reported headaches was confirmed independently and post hoc using an algorithm that was created for that purpose (Figure 1). The algorithm, accounting for migraine symptoms and reported headache severity, sequentially applied the following criteria:

Reported headache pain (severity): for this criterion, severity ratings obtained from the original scales (0–4) were utilized.

Number of migraine symptoms reported (aura, nausea/vomiting, photo- or phono-sensitivity and neck pain).

Patient activities during a severe headache, including maintenance of pre-headache activity, medication and forced rest.

Monthly frequency of headache occurrence for non-continuous headache.

Figure 1.

Flowchart for determining the most important headache (HA) for each subject.

Cohen's k coefficient was utilized in order to assess the degree of agreement between these two methods of determining a categorical variable: the clinically most important headache. k estimates greater than 0.80 provide evidence of strong agreement (33).

Approval for this study was obtained from the Institutional Review Board of WAMC with timely renewals as required.

Results

Demographics

The sample of 95 soldiers consisted of 89 males (93.7%) and six females (6.3%) with a mean age of 31.3 ± 7.4 years (median: 30.0; minimum, maximum: 20, 49). Sixty-seven (70.5%) had some college or graduated, and the majority (71/95; 74.7%) were junior enlisted or non-commissioned officers. Thirteen (13.7%) patients reported a prior history of recurrent headache, all with unknown or no diagnosis. A total of 36/91 (39.6%; data missing for four soldiers) reported a history of concussion prior to military service. A total of 24/85 (28.2%) reported a family history of headache.

Injury characteristics

The most common injury cited by the soldiers as causative was blast (53.7%), followed by parachute jump (23.2%) and motor vehicle accidents (10.5%). The mean time from injury to the initial consultation was 27.6 ± 26.6 months (median: 20; minimum, maximum: 1, 132).

Headache characteristics

Ninety-five soldiers described 166 headaches (mean: 1.7 ± 0.7; range: 1–3), with 54 (56.8%) reporting more than one type. A total of 71.6% (n = 68) had at least one headache of any migraine type. Typical aura was described by 10 (10.5%), with none describing aura prior to injury. Seventy-one (74.7%) reported a continuous headache of any type. For all subjects, the mean number of headache days estimated in the previous month was 26.7 ± 6.8, with severe headaches occurring on 16.9 ± 9.7 days (Table 1). Two patients reported headache days of fewer than 10, with 85.0% reporting greater than 15 headache days per month (data not shown).

Table 1.

Headache characteristics (sample n = 95).

Number of headache types	Statistics^a
1	41 (43.2)
2	37 (38.9)
3	17 (17.9)
Migraine type	68 (71.6)
Continuous headache	71 (74.7)
Headache days
Mean ± (SD)	26.7 (6.8)
Median	30.0
Minimum	2
Maximum	30
IQR	0
Headache – severe days
Mean ± (SD)	16.9 (9.7)
Median	15.0
Minimum	0
Maximum	30
IQR	22
Onset ≤ 7 days, n (%)	73 (76.8%)

Statistics are counts (percentages in parentheses), except where indicated.

IQR: interquartile range.

Headache onset

Most (76.8%) subjects recalled the onset of any headache within 7 days of injury. The 22 subjects who did not report headache onset within 7 days of injury were divided into three sets (Supplemental Table 2). The first set (n = 13) reported a specific time of headache onset: seven (53.8%) reported more than 7 days but less than 30 days from injury; two (15.4%) reported between 1 and 3 months; one (7.7%) reported between 3 and 6 months; and three (23.1%) reported greater than 6 months. A second set (n = 7) had unknown times of headache onset, based upon patient response or inability to confirm time of onset from chart reviews. Only one had a continuous headache (CHCM). In a third set (n = 2), multiple concussions were sustained and subjects could not identify a signature or approximate date. Of the patients who did not report headache onset within 7 days of injury, 4/22 had more than one headache type (<30 days: two patients; multiple concussions: two patients).

Headache diagnosis

For the 166 headaches, there were a total of 31 diagnoses, including five which could not be assigned (ICHD-II: 14.1) (Table 2). Almost 75% of the headaches (n = 124) were attributed to six diagnoses: 1.1 (n = 31), 1.2.1 (n = 10), 1.5.1 (n = 14), 2.3 (n = 28), 2.3/1.5.1 (n = 29) and 4.7 (n = 12). Of these top six diagnoses, 67.7% (n = 84) were migraine type and 50.8% (n = 63) were continuous (data not shown).

Table 2.

International Classification of Headache Disorders second edition diagnoses of all headaches within major categories^a.

ICHD-II headache type	ICHD-II code	Total^b
Continuous headaches with migraine features	2.3/1.1	1 (0.6)
	2.3/1.5.1	29 (17.5)
	2.3/1.5.1/1.2.1	1 (0.6)
Migraine	1.1	31 (18.7)
	1.2.1	10 (6.0)
	1.5.1	14 (8.4)
	1.6.1	1 (0.6)
	1.6.5	2 (1.2)
Tension-type headache	2.1	1 (0.6)
	2.2	2 (1.2)
	2.3	28 (16.9)
Cluster headache and other trigeminal autonomic cephalalgias	3.1.2	6 (3.6)
	3.4	1 (0.6)
	3.4.2	2 (1.2)
	3.4.3	1 (0.6)
Other primary headaches	4.1	3 (1.8)
	4.3	1 (0.6)
	4.7	12 (7.2)
Headache attributed to head and/or neck trauma	5.7.2	1 (0.6)
Headache attributed to non-vascular intracranial disorder	7.2	1 (0.6)
Headache or facial pain attributed to disorder of cranium, neck, eyes, ears, nose, sinuses, teeth, mouth or other cranial or facial structures	11.2	1 (0.6)
	11.5	1 (0.6)
	11.7	1 (0.6)
	11.8	1 (0.6)
Cranial neuralgias and central causes of facial pain	13.1	1 (0.6)
	13.1.2	2 (1.2)
	13.1.2.1	1 (0.6)
	13.6	1 (0.6)
	13.7.1	1 (0.6)
	13.8	3 (1.8)
Headache not elsewhere classified	14.1	5 (3.0)

This table summarizes all headaches observed (n = 166); some individuals were diagnosed with multiple headaches – see text.

Percentages do not sum to 100 due to rounding; values are counts (percentages in parentheses).

ICHD-II: International Classification of Headache Disorders second edition.

Highlighted amongst patients (n = 95), chronic migraine type (1.5.1) occurred in 14 (14.7%), migraine with aura type (1.2.1) occurred in ten (10.5%) and HC type occurred in 12 (12.6%), including two who had daily but non-continuous pain. Chronic cluster type was diagnosed in six patients (6.3%), as were other primary headaches, including primary stabbing type and primary exertional headache in three each (3.2%). Nummular headache was diagnosed in one patient, with six (6.3%) secondary headache types and ten (10.4%) with cranial neuralgias and central causes of facial pain (ICHD-II 13.x). Five soldiers had headaches not otherwise classifiable (Supplemental Table 1 displays the individual patients and all diagnoses).

Headache profiles

There were 53 individual combinations or “profiles” for patients (Supplemental Table 3), and 40 (75.5%) of these profiles contained more than one headache. The top seven profiles described 43.2% of subjects (n = 41); only five of these patients did not have a continuous headache.

Most clinically important

Final grouping into the major primary headache categories yielded migraine type as being most prevalent (n = 58; 61.1%), followed by TAC type (n = 23; 24.2%) then tension type, other primary type and secondary headaches each with five (5.3%) (Table 3). The post hoc algorithm resulted in only two “ties” requiring application of the third criterion (frequency of episodic headaches). Both were migraine without aura (1.1) diagnoses. Agreement of the two methods was favorable (grouping by a clinician and independent algorithmic classification concurred in all but seven subjects; κ = 0.81 (95% confidence interval (CI): 0.72–0.90)). When including only subjects whose most impactful headache was a primary headache diagnosis, agreement assessed with κ was 0.89 (95% CI: 0.81–0.98). Agreement significantly differed from chance levels (p < 0.0001). Two of the disagreements were computer reading errors and the other five were clinician decisions based upon uniqueness in the two with HC and the one with migraine with aura versus CHCM. Clinician determination of importance accounted for the other two disagreements, one each with chronic migraine and CHCM versus migraine without aura. See Table 4 for details of discordance.

Table 3.

Final categories by major classification for most clinically important headache identified^a.

Category	Total (%)
Migraine	58 (61.1)
Tension type	4 (4.2)
TAC (HC, n = 12)	23 (24.2)
Other primary	5 (5.3)
Secondary, including NEC	5 (5.3)

Continuous headache chronic migraine is included as migraine. HC was included in the TAC category following the International Classification of Headache Disorders third edition.

HC: hemicrania continua; NEC: not elsewhere classified; International Classification of Headache Disorders second edition code 14.1; TAC: trigeminal autonomic cephalalgia.

Discussion

The classification of headaches after concussive or non-concussive injury to the head, neck or face depends on many factors. Originally classified as “concussion reactions” under Category VI.B, non-migraine vascular headaches, of the American Academy of Neurology Ad Hoc Committee on Classification of Headache, PTH was included with, amongst others, carbon monoxide poisoning, caffeine “circulatory insufficiency in the brain” and “hangover reactions” (Supplemental Figure 1) (34). The International Headache Society Classification of Headache (first edition) (35) describes chronic PTH according to “significant” or “minor” head trauma (Supplemental Figure 2) where: “Headache occurs less than 14 days after injury, Headache continues more than 8 weeks after injury and there is no: 1. loss of consciousness; 2. posttraumatic amnesia lasting more than 10 minutes; or 3. at least 2 of the following exhibit relevant abnormality: Clinical neurological examination, x-ray of skull, neuroimaging, evoked potential, spinal fluid examination, vestibular function tests, neuropsychological testing.” No mention of headache characteristics is stated, and the preface to Section 5 acknowledges chronic PTH as “often part of the post-traumatic syndrome”. The second edition of the ICHD based diagnosis of PTH upon the severity of trauma by Glasgow Coma Scale, “onset within 7 days after injury” and the chronic type was a “headache which continues more than 3 months” (Figure 2) (36). The Committee states that the headaches have “no typical characteristics known” (emphasis added). The most recent classification (ICHD-III beta version) (36) has added the term “persistent” to “any headache” that meets the onset criteria lasting greater than 3 months (Figure 3). This change recognizes the complications of onset timing when headaches can begin within 7 days of “regaining consciousness” or “discontinuation of medication(s) that impair ability to sense or report headache…”. The time course of “greater than 3 months after injury” for chronic PTH is repeated and the inclusion of other persistent symptoms that are typically associated with mild concussion is not mandated. Appendix Criteria A5.x for delayed-onset headaches attributed to traumatic injury of the head allows attribution of headaches that have onset at more than 7 days but less than 30 days after injury, at least in the introduction. In addition to headaches with uncertain onset in relation to injury, attribution after 1 month may be difficult to reconcile with most of these cases. In a seminal paper on the subject of headache onset after TBI, Walker et al. reported new-onset headaches at all time points recorded (i.e. 6 and 12 months from the time of injury) (19). These findings were also replicated in a more recent prospective study in which the injuries were considered mild and the incidence of PTH continued to increase through the first 3 months after injuries (31).

Figure 2.

International Classification of Headache Disorders (second edition) (2004) (35).

Figure 3.

International Classification of Headache Disorders (third edition, beta) (36).

Table 4.

Discordances between post hoc algorithm and clinician diagnosis of most clinically important in individual subjects.

Source		Headache by duration and diagnosis^b			Reason for change
Algorithm based	Clinician based^a	Continuous	Non- continuous 1	Non- continuous 2	Reason for change
14.1	4.7	4.7	14.1	X	Reading error
2.3	11.7	2.3	11.7	X	Reading error
1.2.1	4.7	4.7	1.2.1	X	Clinician decision – unique versus uncommon
1.1	1.5.1	X	1.5.1	1.1	Clinician decision – prominent
1.2.1	4.7	4.7	1.2.1	X	Clinician decision – unique versus uncommon
1.1	2.3/1.5.1	2.3/1.5.1	1.1	X	Clinician decision – prominent
2.3/1.1	1.2.1	2.3/1.1	1.2.1	X	Clinician decision – prominent and uncommon

Most clinically important are displayed in bold.

“X” indicates that no headache was reported.

Our group of active-duty service members presented with a multitude of headache descriptions at an average of more than 2 years from their reported signature injury. We used direct interview and medical record review to confirm concussion or “symptoms and/or signs diagnostic of concussion” (37) and diagnosed each headache according to the extant classification in use at the time. The most common diagnosis was a mixed CHCM type, with the next most common types being migraine without aura and chronic tension type, either continuous or non-continuous. Overall, the largest category of described headaches was migraine, and we noted that continuous headaches could occur across diagnostic categories. There were non-continuous headaches of the less common type, including TAC and other primary headaches.

We describe a variety of onset dates, including a group of headaches that were reported to begin later than 14 days (35) or 7 days (36,37) from the time of injury. All patients had headaches that were persistent for more than 3 months after head trauma, including those few who were seen within fewer than 3 months after their concussion. The time from injury to evaluation was variable, but on average, we found that many still had headaches at 2 years after concussion.

We did not attempt to apply statistical formulae or to ascribe any possible relationships to demographics or injury type or the outcomes that we observed (not reported here). The primary goal of this study was to demonstrate that close assessment of patients in this population can yield diagnosis types other than migraine type.

Why does this matter? In our clinical observation of a population of mostly male soldiers, there are more than just migraine features with which to deal. In a recent epidemiologic sampling at 1 year post-injury of mixed severity, migraine and probable migraine types were most prevalent (54%), followed by tension type (21%), cervicogenic (4%) and unclassifiable (21%), with those with only mild TBI having similar rates of migraine/probable migraine (49%), tension type (32%), cervicogenic (4%) and unclassifiable headaches (17%) (38). Our finding of other headache types may suggest that prescription of medications with efficacy in other diagnoses should be considered; for example, verapamil in cluster type, indomethacin in short duration or hemicrania types, etc. These subtleties may not be apparent in larger epidemiologic studies or clinic trials using survey or questionnaire data to determine control drug trials (e.g. we found that chronic migraine type may have better outcomes than continuous type when treated with onabotulinum toxin A, and in that study, the time from injury to treatment may have improved the efficacy) (39). In addition, the anecdotally high failure rate of the standard of care for PTH of the migraine type may relate to the presence of changes expressed as a second and perhaps more unique headache diagnosis types.

In developing guidelines and standard operating procedures, the gold standard is always going to be clear delineation of diagnosis and the application of evidence- or consensus-based treatments. Our findings may have implications for primary care or general neurology in the military setting, where stratification of medication or procedural management is important, but Continuation on Active Duty and deployment readiness are paramount. Finally, the factors that lead to persistence may be different for more non-specific headache types, such as tension type or tension type with migraine features (the largest group combined), and in our future reports, we will address the question of such associations.

The shortcomings of a phenomenological study of individuals with subjective complaints are obvious. Reliance upon patient report always presumes some difficulties in addition to the recall of injury and symptom progression over time. These may also be based upon education, prior experience, ability to express symptoms consistently and possible motive or intent on the part of the individual to gain attention or secondary advantages. We did not address any of these issues, relying upon a historical classification system in current use at the time of the patient's initial evaluation. We were able to show that the criteria were applicable in the vast majority of cases.

Additional criticism of the work could include what might be called “shoe-horning” symptoms into diagnosis typing. The utility to applying criteria to individual headaches in specific patients is the cornerstone of headache medicine. Changes to the criteria for PTH and chronic PTH (Figures 2 and 3; Supplemental Figures 1 and 2) through time may have introduced more specific terms, with the most recent ICHD-III beta recognizing that “any headache” that could be attributed differs substantially from “no typical characteristics”. Application of this criterion may need to be tested in field trials. Those same authors also allow for onset after 7 days post-injury.

Using these ideas, we proposed that clinically diagnosed and retrospectively reviewed medical records could yield criteria that were positive diagnoses for individual headaches and individuals with PTHs. These were based upon best clinical judgement at the point of contact and on the analysis of granular details collected retrospectively. Best attempts to match criteria exactly were made, and choices between diagnoses, where unclear, aimed to best match existing primary headache classification.

Another prominent concern must be that study participants may be biased to report a close temporal association between the impugned injury and the timing of headache onset (i.e. < 7 days post-injury). Historically, assumptions have been that highly selected responders may have negative motivational factors related to monetary awards (e.g. disability benefits) (40), comorbidities (41) or distress related to the context of injury (e.g. directly attributable to concussion, such as PTSD) (24).

In light of these and possibly other legitimate arguments, our highly selected cohort that was referred for definitive evaluation to a headache specialist at an average of 2 years after headache onset demonstrated a surprisingly high prevalence of cluster and other TAC-type headaches, leading some to be legitimately skeptical of our reporting. The literature has very few cases of these types of headaches attributed to mild head trauma. Those arguing thus could further suggest that the absence of contemporaneous medical records describing headache phenomenology and symptomatology from the moment of concussion to the immediate period afterwards led us to rely upon a retrospectively determined timing of headache based upon a forced choice of fixed time periods for headache onset. Acknowledging this during our review, we strictly adhered to criteria, including those with “probable” TAC type, all having only one missing criterion. Whether this occurrence relates to patient variables or transition in central and peripheral structures implicated in TAC-type headaches or problems of symptom interpretation, etc., cannot be known. We note that a possible association with changes in hypothalamic–pituitary function has been proposed in concussion (42,43). Speculating on the onset of a more complex headache disorder such as these TAC types, it is worth noting that three out of ten of our subjects had onset either unknown onset, onset at >7 but < 30 days post-injury or onset after multiple injuries. Whether this should be interpreted as a change in anatomy or physiology (44 –46) is an open question, including whether the entire discussion is moot (e.g. headache is not a post-concussive complication) (30). Opposing this argument, imaging results in mild TBI have shown both functional and anatomical changes (47,48).

In an attempt to confirm the clinical impression using this approach based on objective criteria, one of us (JSK) created an algorithm to test whether control of severity, migraine criteria and headache-associated disability could replicate the clinician-determined diagnoses of the most clinically important headaches. Use of the clinician's sense of uniqueness to stratify headaches in patients with more than one type of headache, as well as determination of the most clinically important headache, was largely (although not completely) replicated. In patients with more than one type of headache, we found concordance in all but a few comparisons (>90%). Replication also included the relatively high prevalence of TACs observed. Though some clinician-detected nuances were not accounted for by this algorithm, this type of approach may offer future opportunities to create methods for sub-classifying secondary headaches of no known characteristics.

Lastly, few statistics were applied to the data we present. This leaves unanswered questions such as: are there predictors of diagnoses or types that could be easily used to help clinicians at all levels to treat or prognosticate? Do patients with certain headache types have different injuries? Do headache types in combination with medical histories and demographics predict outcomes?

In conclusion, we present a series of patients seen in a military treatment facility for headache diagnosis after concussion. Prior publications in non-traumatic headaches have attempted to view diagnosis through a microscopic (49 –53) or phenomenological lens (54,55) for the purposes of clarifying the heterogeneous nature of even the most common headaches. To that end, where there has been reliance upon field trials for validations (56 –60), including PTH (61), there have also been refutations of the claims for classification as being truly representative of the phenomenology and thus epidemiology of individual headache diagnoses (62).

We did find that the prevalence of migraine is high, but we also included headache types that met specific criteria for other primary headaches. We were able to group patients and headaches by creating “profiles” and, lastly, by identifying the most clinically important headache. We found only five soldiers each (5.3%) in which tension type, other primary or secondary headache were most important. A review of the last 10 years of publications (search terms “post traumatic headache”) (63) showed that 26% (121/458) were under the categorical heading that included cervicogenic. On the other hand, we found essentially no cases in which cervicogenic was either the only headache type or the most important type. However, migraine type was most prevalent, but, interestingly, TAC type was the second most prevalent, raising the possibility that more focal, severe and episodic headaches may suggest a relationship with the mechanism of injury. In an historical footnote, those papers relating cluster headache patients to head injury or violence suggest that the pugnacious nature of males with cluster headaches, including the authors' noting of alcohol seeking, may be a part of the reason for some of this association (64 –67). The relevance of this to service members is not implied, but war, by definition, involves fighting. In this same vein, the generalizability of all of the diagnostic findings reported here may be limited to specific populations and/or injuries.

This disparity may suggest that intensive diagnostic interview in combination with stringent applications of classification can help the clinician determine upon which of the possibly multiple headache types to focus evaluation and treatment. Lastly, the results of a directed diagnostic process may help to determine clinical outcomes or surrogates in lieu of reliable biomarkers. Future prospective and longitudinal studies are indicated.

Article highlights

Ninety-five soldiers injured during the wars in Afghanistan and Iraq were seen consecutively by a certified headache specialist for diagnosis.

The most common diagnosis was a continuous headache with migraine features.

Twenty-two subjects did not report the onset of headache within the 7 days stipulated by the International Classification of Headache Disorders. Of these, seven had unknown onset and seven had onset between 7 and 30 days.

Uncommon headaches, including cluster headaches, were seen in higher prevalence than would be expected, raising the possibility of central nervous system and hypothalamic–pituitary changes.

An innovative approach using an algorithm based upon most severe headache characteristics was employed, showing a high level of correlation with clinically determined diagnosis.

Footnotes

Disclosure

The views expressed herein are those of the authors and do not reflect the official policy of the Department of the Army, Department of Defense, the Uniformed Services University or the US Government.

Declaration of conflicting interests

The authors declared the following potential conflicts of interest with respect to the research, authorship and/or publication of this article: One of the authors (AGF) received salary support from the Defense and Veterans Brain Injury Center and General Dynamics Information Technology for work associated with this study.

Funding

The authors disclosed receipt of the following financial support for the research, authorship and/or publication of this article: Funding was received from the Defense and Veterans Brain Injury Center.

References

Defense and Veterans Brain Injury Center. Progressive return to activity following acute concussion/mild traumatic brain injury: Guidance for the primary care manager in deployed and non-deployed settings, https://dvbic.dcoe.mil/resources/progressive-return-to-activity (2014, accessed 31 May 2014).

Defense and Veterans Brain Injury Center. Mild traumatic brain injury pocket guide (CONUS). Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury website, https://dvbic.dcoe.mil/sites/default/files/DCoE_mTBI-Pocket-Guide.pdf (2009, accessed 31 May 2014).

Giza

Kutcher

Ashwell

. Summary of evidence-based guideline update: Evaluation and management of concussion in sports: Report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology 2013; 80(24): 2250–2271.

Covassin

Elbin

3rd Stiller-Ostrowski

. Immediate post-concussion assessment and cognitive testing (ImPACT) practices of sports medicine professionals. J Athl Train 2009; 44(6): 639–644.

Echemendia

Bruce

Bailey

. The utility of post-concussion neuropsychological data in identifying cognitive change following sports-related MTBI in the absence of baseline data. Clin Neuropsychol 2012; 26(7): 1077–1091.

De Marco

Broshek

. Computerized cognitive testing in the management of youth sports-related concussion. J Child Neurol 2016; 31(1): 68–75.

King

Horak

Mancini

. Instrumenting the balance error scoring system for use with patients reporting persistent balance problems after mild traumatic brain injury. Arch Phys Med Rehabil 2014; 95(2): 353–359.

Ventura

Balcer

Galetta

. The neuro-ophthalmology of head trauma. Lancet Neurol 2014; 13(10): 1006–1016.

Soble

Silva

Vanderploeg

. Normative data for the Neurobehavioral Symptom Inventory (NSI) and post-concussion symptom profiles among TBI, PTSD, and nonclinical samples. Clin Neuropsychol 2014; 28(4): 614–632.

10.

Kristman

Borg

Godbolt

. Methodological issues and research recommendations for prognosis after mild traumatic brain injury: Results of the International Collaboration on Mild Traumatic Brain Injury Prognosis. Arch Phys Med Rehabil 2014; 95(3 Suppl): S265–S277.

11.

US Army (2009) Traumatic Brain Injury: Symptoms, Diagnosis, Treatment. Army Medicine. 27 February 2009. https://www.army.mil/article/17566/traumatic-brain-injury-symptoms-diagnosis-treatment (accessed 13 May 2016).

12.

Sullivan

Edmed

Kempe

. The effect of injury diagnosis on illness perceptions and expected postconcussion syndrome and posttraumatic stress disorder symptoms. J Head Trauma Rehabil 2014; 29(1): 54–64.

13.

Hartmann

. Neurology in Operation Iraqi Freedom: Risk factors for referral,clinical presentations and incidence of disease. J Neurol Sci 2006; 241(1–2): 83–90.

14.

Rigg

Mooney

. Concussions and the military: Issues specific to service members. PM R 2011; 3(10 Suppl. 2): S380–S360.

15.

Theeler

Lucas

Riechers

2nd . Post-traumatic headaches in civilians and military personnel: A comparative, clinical review. Headache 2013; 53(6): 881–900.

16.

Theeler

Mercer

Erickson

. Prevalence and impact of migraine among US Army soldiers deployed in support of Operation Iraqi Freedom. Headache 2008; 48(6): 876–882.

17.

Theeler

Erickson

. Mild head trauma and chronic headaches in returning US soldiers. Headache 2009; 49: 529–534.

18.

Armed Forces Health Surveillance Branch. Medical Surveillance Monthly Report. Incident diagnoses of common symptoms (“sequelae”) following traumatic brain injury, active component, U.S. Armed Forces, 2000– 2012, http://www.afhsc.mil/viewMSMR?file=2013/v20_n06.pdf (2013, accessed 31 May 2014).

19.

Walker

Seel

Curtiss

. Headache after moderate and severe traumatic brain injury: A longitudinal analysis. Arch Phys Med Rehabil 2005; 86(9): 1793–1800.

20.

Cohen

Plunkett

Wilkinson

. Headaches during war: Analysis of presentation, treatment, and factors associated with outcome. Cephalalgia 2012; 32(2): 94–108.

21.

Patil

St Andre

Crisan

. Prevalence and treatment of headaches in veterans with mild traumatic brain injury. Headache 2011; 51(7): 1112–1121.

22.

Ruff

Riechers

2nd Wang

. For veterans with mild traumatic brain injury, improved posttraumatic stress disorder severity and sleep correlated with symptomatic improvement. J Rehabil Res Dev 2012; 49(9): 1305–1320.

23.

Hoge

McGurk

Thomas

. Mild traumatic brain injury in U.S. soldiers returning from Iraq. N Engl J Med 2008; 358: 453–456.

24.

Rosenthal

Erickson

. Post-traumatic stress disorder in U.S. soldiers with post-traumatic headache. Headache 2013; 53(10): 1564–1572.

25.

Watanabe

Bell

Walker

. Systematic review of interventions for post-traumatic headache. PM R 2012; 4(2): 129–140.

26.

Erickson

. Treatment outcomes of chronic post-traumatic headaches after mild head trauma in US soldiers: An observational study. Headache 2011; 51(6): 932–944.

27.

Ruff

Wang

. Improving sleep: Initial headache treatment in OIF/OEF veterans with blast-induced mild traumatic brain injury. J Rehabil Res Dev 2009; 46: 1071–1084.

28.

Hoffman

Lucas

Dikmen

. Natural history of headache after traumatic brain injury. J Neurotrauma 2011; 28(9): 1719–1725.

29.

van Reekum

. Should post-traumatic headaches be considered a post-concussive symptom? Brain Inj 2013; 27(10): 1210–1211.

30.

Rapp

Curley

. Is a diagnosis of “mild traumatic brain injury” a category mistake? J Trauma Acute Care Surg 2012; 73(2 Suppl. 1): S13–S23.

31.

Lucas

Hoffman

Bell

. A prospective study of prevalence and characterization of headache following mild traumatic brain injury. Cephalalgia 2014; 34(2): 93–102.

32.

Finkel

Yerry

Scher

. Headaches in soldiers with mild traumatic brain injury: Findings and phenomenologic descriptions. Headache 2012; 52(6): 957–965.

33.

McHugh

. Interrater reliability: The kappa statistic. Biochem Med (Zagreb) 2012; 22(3): 276–282.

34.

Friedman

Finley

Graham

. A classification of headache: Ad Hoc Committee on Classification of Headache. 1962; 12: 378–380. .

35.

Headache Classification Committee of the International Headache Society. Classification and diagnostic criteria for headache disorders, cranial neuralgias and facial pain. Headache Classification Committee of the International Headache Society. Cephalalgia 1988; 8(Suppl. 7): 1–96.

36.

Headache Classification Committee of the International Headache Society. The International Classification of Headache Disorders. Second edn. Cephalalgia. 2004(Suppl. 1): 1–160.

37.

Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition (beta version). Cephalalgia 2013; 33(9): 629–808.

38.

Lucas

Hoffman

Bell

. Characterization of headache after traumatic brain injury. Cephalalgia 2012; 32(8): 600–606.

39.

Yerry

Kuehn

Finkel

. Onabotulinum toxin A for the treatment of headache in service members with a history of mild traumatic brain injury: A cohort study. Headache 2015; 55(3): 395–406.

40.

Evans

. Persistent post-traumatic headache, postconcussion syndrome, and whiplash injuries: The evidence for a non-traumatic basis with an historical review. Headache 2010; 50(4): 716–724.

41.

Cifu

Taylor

Carne

. Traumatic brain injury, posttraumatic stress disorder, and pain diagnoses in OIF/OEF/OND veterans. J Rehabil Res Dev 2013; 50(9): 1169–1176.

42.

Niederland

Makovi

Gál

. Abnormalities of pituitary function after traumatic brain injury in children. J Neurotrauma 2007; 24(1): 119–127.

43.

Tanriverdi

Unluhizarci

Kelestimur

. Pituitary function in subjects with mild traumatic brain injury: A review of literature and proposal of a screening strategy. Pituitary 2010; 13(2): 146–153.

44.

Henry

Tremblay

Boulanger

. Neurometabolic changes in the acute phase after sports concussions correlate with symptom severity. J Neurotrauma 2010; 27(1): 65–76.

45.

MacFarlane

Glenn

. Neurochemical cascade of concussion. Brain Inj 2015; 29(2): 139–153.

46.

Giza

Hovda

. The new neurometabolic cascade of concussion. Neurosurgery 2014; 75(Suppl. 4): S24–S33.

47.

Gardner

Iverson

Stanwell

. A systematic review of proton magnetic resonance spectroscopy findings in sport-related concussion. J Neurotrauma 2014; 31(1): 1–18.

48.

Gardner

Kay-Lambkin

Stanwell

. A systematic review of diffusion tensor imaging findings in sports-related concussion. J Neurotrauma 2012; 29(16): 2521–2538.

49.

Kelman

. The triggers or precipitants of the acute migraine attack. Cephalalgia 2007; 27(5): 394–402.

50.

Kelman

Tanis

. The relationship between migraine pain and other associated symptoms. Cephalalgia 2006; 26(5): 548–553.

51.

Kelman

. Migraine pain location: A tertiary care study of 1283 migraineurs. Headache 2005; 45(8): 1038–1047.

52.

Kelman

. Pain characteristics of the acute migraine attack. Headache 2006; 46(6): 942–953.

53.

Kelman

. The aura: A tertiary care study of 952 migraine patients. Cephalalgia 2004; 24(9): 728–734.

54.

Wheeler

. Phenotype-driven preventive strategies for migraine and other headaches. Neurologist 2009; 15(2): 59–70.

55.

Ward

. Migraine diagnosis and pathophysiology. Continuum (Minneap Minn) 2012; 18(4): 753–763.

56.

Solomon

Lipton

. A headache clinic-based approach to field trials of the International Headache Society criteria. Cephalalgia 1993; 13(Suppl. 12): 63–65.

57.

Nash

Lipchik

Holroyd

. American Headache Society. American Headache Society members' assessment of headache diagnostic criteria. Headache 2003; 43(1): 2–13.

58.

Solomon

. Diagnosis of primary headache disorders. Validity of the International Headache Society criteria in clinical practice. Neurol Clin 1997; 15(1): 15–26.

59.

Bigal

Tepper

Sheftell

. Chronic daily headache: Correlation between the 2004 and the 1988 International Headache Society diagnostic criteria. Headache 2004; 44(7): 684–691.

60.

Gallai

Sarchielli

Alberti

. Collaborative Group for the Application of IHS Criteria of the Italian Society for the Study of Headache. Application of the 1988 International Headache Society diagnostic criteria in nine Italian headache centers using a computerized structured record. Headache 2002; 42(10): 1016–1024.

61.

Baandrup

Jensen

. Chronic post-traumatic headache – A clinical analysis in relation to the International Headache Classification 2nd edition. Cephalalgia 2005; 25(2): 132–138. Erratum in: Cephalalgia 2005; 25(3): 240.

62.

Shevel

Sevel

. The international headache society classification of migraine headache – A call for substantiating data. J Biomed Sci Eng 2014; 7: 112–114.

63.

PubMed. http://www.ncbi.nlm.nih.gov/pubmed/?term=post+traumatic+headache+and+cervical AND http://www.ncbi.nlm.nih.gov/pubmed/?term=post+traumatic+headache (accessed 15 March 2015).

64.

Lambru

Matharu

. Traumatic head injury in cluster headache: Cause or effect? Curr Pain Headache Rep 2012; 16(2): 162–169.

65.

Manzoni

Lambru

Torelli

. Head trauma and cluster headache. Curr Pain Headache Rep 2006; 10(2): 130–136.

66.

Walker

. Cluster headache and head trauma: Is there an association? Curr Pain Headache Rep 2007; 11(2): 137–140.

67.

Turkewitz

Wirth

Dawson

. Cluster headache following head injury: A case report and review of the literature. Headache 1992; 32(10): 504–506.

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