Table 3. Clinical Features Reported in 111 American Football Players Diagnosed as Having CTE, Stratified by Neuropathological Severitya.
| Clinical Features | No. (%) of Brain Donors | ||
|---|---|---|---|
| Mild CTE | Severe CTE | Total | |
| Progressive course | 23 (85) | 84 (100) | 107 (96) |
| Cognitive symptomsb | 23 (85) | 80 (95) | 103 (93) |
| Memory | 19 (73) | 76 (92) | 95 (86) |
| Executive function | 19 (73) | 67 (81) | 86 (79) |
| Attention | 18 (69) | 67 (81) | 85 (78) |
| Language | 10 (39) | 54 (66) | 64 (59) |
| Visuospatial | 7 (27) | 44 (54) | 51 (47) |
| Fluctuating cognition | 2 (8) | 17 (21) | 19 (18) |
| Dementiab | 9 (33) | 71 (85) | 80 (72) |
| Behavioral or mood symptomsb | 26 (96) | 75 (89) | 101 (91) |
| Impulsivity | 23 (89) | 65 (80) | 88 (82) |
| Depressive symptoms | 18 (67) | 46 (56) | 64 (59) |
| Explosivity | 18 (67) | 38 (45) | 56 (51) |
| Apathy | 13 (50) | 43 (52) | 56 (51) |
| Anxiety | 14 (52) | 41 (50) | 55 (51) |
| Hopelessness | 18 (69) | 36 (46) | 54 (52) |
| Verbal violence | 17 (63) | 28 (34) | 45 (41) |
| Social inappropriateness | 13 (48) | 26 (32) | 39 (36) |
| Physical violence | 14 (52) | 23 (28) | 37 (34) |
| Paranoia | 11 (41) | 26 (31) | 37 (34) |
| Suicidality (ideation, attempts, or completions) | 15 (56) | 21 (25) | 36 (33) |
| Visual hallucinations | 6 (23) | 22 (27) | 28 (26) |
| Mania | 6 (22) | 3 (4) | 9 (8) |
| Posttraumatic stress disorder (exposure and symptoms consistent with) | 3 (11) | 9 (11) | 12 (11) |
| Substance use disorder | 18 (67) | 41 (49) | 59 (53) |
| Alcohol | 13 (50) | 31 (37) | 44 (41) |
| Anabolic steroid | 0 | 4 (5) | 4 (4) |
| Other | 14 (54) | 23 (28) | 37 (34) |
| Motor symptomsb | 13 (48) | 63 (75) | 76 (68) |
| Gait instability | 7 (26) | 55 (66) | 62 (56) |
| Slowness | 5 (19) | 42 (50) | 47 (42) |
| Coordination difficulties | 7 (26) | 38 (45) | 45 (41) |
| Falls | 4 (15) | 39 (46) | 43 (39) |
| Tremor | 5 (19) | 33 (39) | 38 (34) |
| Dysphagia | 3 (11) | 14 (18) | 17 (16) |
| Dysarthria | 5 (19) | 10 (13) | 15 (14) |
| Headache | 8 (30) | 11 (14) | 19 (18) |
| Diagnoses in life | |||
| Motor neuron disease | 1 (4) | 3 (4) | 4 (4) |
| Parkinson disease | 1 (4) | 5 (6) | 6 (6) |
| Alzheimer disease | 1 (4) | 21 (25) | 22 (20) |
| Obstructive sleep apnea (diagnosis or symptoms) | 7 (27) | 36 (46) | 43 (41) |
| Rapid eye movement sleep behavior disorder (diagnosis or symptoms) | 7 (27) | 23 (29) | 30 (29) |
Abbreviation: CTE, chronic traumatic encephalopathy.
There were 111 participants with standardized informant reports, including 27 participants with mild CTE and 84 participants with severe CTE. Sample sizes differed across clinical features because features marked as unknown by the clinician were excluded. For participants with mild CTE, sample sizes ranged from 25 to 27 and for participants with severe CTE, sample sizes ranged from 78 to 84. Mild CTE (CTE neuropathological stages I and II) is characterized by sparse to frequent perivascular CTE lesions at the sulcal depths of the cerebral cortex. Severe CTE (CTE neuropathological stages III and IV) consists of multiple CTE lesions in the cerebral cortex and moderate to severe neurofibrillary degeneration of medial temporal lobe, diencephalon, and brain stem.
Symptoms were present in the last year of life.