The role of deficient pain modulatory systems in the development of persistent post-traumatic headaches following mild traumatic brain injury: an exploratory longitudinal study

Table 1 Participant Characteristics

	*PPTH Group (n = 21*	*No-PPTH (n = 21)*
Variable	Mean ± SD	Mean ± SD	p-value
Age, years	29.5 ± 9.4	32.9 ± 9.8	0.253
Sex, % female	66.7%	33.3%	0.013*
Body Mass Index	28.7 ± 9.2	26.8 ± 4.9	0.414
Education
Some HS	5.3%	9.5%
HS degree	47.4%	33.3%
2 year College degree	15.8%	9.0%
4 year College degree	15.8%	28.6%
Masters or above	15.8%	9.5%
Race
African American	38.1%	14.3%
Asian/Pacific Islander	0.0%	4.8%
Caucasian	52.4%	66.7%
Hispanic	4.8%	14.3%
Other	4.8%	0.0%
Frequency of headaches at 1–2 weeks post injury (since injury)
No headaches since injury	0.0%	14.7%
About once a week	4.8%	19.0%
Several times a week	47.6%	33.3%
Daily	42.9%	33.3%
Constant	4.8%	0.0%
Frequency of headaches at 1-month post injury (past month)
No headaches since 1-week visit	0.0%	33.3%
About once a month	14.3%	19.0%
About once a week	33.3%	19.0%
Several times a week	23.8%	23.8%
Daily	23.8%	4.8%
Constant	4.8%	0.0%
Frequency of headaches at 4-months post injury (past 3 months)
No headaches since 1-month visit	0.0%	57.1%
Less than once a month	0.0%	42.9%
At least once a month	14.3%	0.0%
About once a week	52.4%	0.0%
Several times a week	28.6%	0.0%
Daily	4.8%	0.0%
Constant	0.0%	0.0%

ISSN: 1129-2377