Table 2.

Summary of demographic, clinical features, outcomes, and quantitative brain magnetic resonance imaging CO₂ stress testing results in sports-related concussion patients.

Subject	Past medical history	Time from injury to imaging assessment (days)	PCSS score at time of imaging assessment	Abnormal voxel counts (at imaging assessment, p < 0.005)	Clinical outcomes
1	3 previous concussions	29	8	Greater: 19,973 Less: 370 Total: 20,343	– Autonomic/physiological PCD – Required medication for post-traumatic headaches – Remained symptomatic at last follow-up (154 days)
2	1 previous concussion	13	82	Greater: 21,008 Less: 268 Total: 21,276	– Clinically recovered (41 days postinjury)
3	2 previous concussions	3	1	Greater: 12,885 Less: 176 Total: 13,061	– Clinically recovered (9 days postinjury)
4	1 previous concussion	27	58	Greater: 1,002 Less: 0 Total: 1,002	– Autonomic/physiological PCD – Remained symptomatic at last follow-up (90 days postinjury)
5	1 previous concussion	7	69	Greater: 2,091 Less: 210 Total: 2,301	– Clinically recovered (34 days postinjury)
6	2 previous concussions, migraine headaches	6	46	Greater: 1,607 Less: 49 Total: 1,656	– Autonomic/physiological PCD – Remained symptomatic at last follow-up (40 days postinjury)
7	2 previous concussions	7	18	Greater: 35,429 Less: 93 Total: 35,522	– Autonomic/physiological PCD – Clinically recovered (140 days postinjury)
8	None	22	56	Greater: 14,695 Less: 11 Total: 14,706	– Autonomic/physiological PCD – Clinically recovered (211 days postinjury)
9	3 previous concussions, depression	4	24	Greater: 12,575 Less: 16 Total: 12,591	– Remains in treatment – Abnormal formal neuropsychological testing (196 days postinjury)
10	2 previous concussions	12	56	Greater: 16,846 Less: 45 Total: 16,891	– Autonomic/physiological PCD – Remained symptomatic at last follow-up (60 days postinjury)
11	1 previous concussion	8	48	Greater: 7,772 Less: 66 Total: 7,838	– Clinically recovered (21 days postinjury)
12	None	27	23	Greater: 4,199 Less: 20 Total: 4,219	– Autonomic/physiological PTD – Clinically recovered (84 days postinjury)
13	None	25	42	Greater: 5,717 Less: 694 Total: 6,411	– Autonomic/physiological PCD – Clinically recovered (39 days postinjury)
14	1 previous concussion	32	20	Greater: 9,890 Less: 0 Total: 9,890	– Autonomic/physiological PCD – Clinically recovered (101 days postinjury)
15	3 previous concussions, migraine headaches	18	71	Greater: 20,331 Less: 15 Total: 20,346	– Autonomic/physiological PCD – BPPV – Clinically recovered (55 days postinjury)

PCSS, Postconcussion Symptom Scale; M, male; F, female; PCD, postconcussion disorder; BPPV, benign paroxysmal positional vertigo.