Six-month recovery from mild to moderate Traumatic Brain Injury: the role of APOE- 4 allele

Abstract

The possession of at least one APOE-epsilon4 allele may be linked to poor outcome in patients with predominantly severe traumatic brain injury (TBI). In mild TBI, which accounts for approximately 85% of all cases, the role of the APOE-epsilon4 allele is less clear. Studies completed to date have relied on brief cognitive assessments or coarse measures of global functioning, thereby limiting their conclusions. Our study investigated the influence of the APOE-epsilon4 allele in a prospective sample of 90 adults with mild to moderate TBI in whom neuropsychiatric outcome 6 months after injury was assessed as follows: (i) a detailed neuropsychological battery; (ii) an index of emotional distress (General Health Questionnaire); (iii) a diagnosis of major depression (Structured Clinical Interview for DSM-IV); (iv) a measure of global functioning (Glasgow Outcome Scale); (v) an index of psychosocial outcome (Rivermead Head Injury Follow-up Questionnaire); and (vi) symptoms of persistent post-concussion disorder (Rivermead Post-Concussion Symptoms Questionnaire). No association was found between the presence of the APOE-epsilon4 allele and poor outcome across all measures. Given the homogeneous nature of our sample (mild to moderate injury severity), the uniform follow-up period (6 months) and the comprehensive markers of recovery used, our data suggest that the APOE-epsilon4 allele does not adversely impact outcome in this group of TBI patients.

Apolipoprotein E4: A causative factor and therapeutic target in neuropathology, including Alzheimer’s disease

“…In some, 40-80% of patients with AD possess at least one apoE4 allele (12). Likewise, apoE4 is associated with earlier onset, progression, or severity of head trauma (13)(14)(15)(16)(17)(18)(19), stroke (20,21), complications after coronary artery bypass surgery (22,23), Parkinson's disease (24)(25)(26)(27), amyotrophic lateral sclerosis (28)(29)(30)(31)(32), multiple sclerosis (33,34), diabetic neuropathy (35), sleep apnea (36), Lewy body disorders (37), and CNS ischemia (38).…”

Mind the gaps—advancing research into short-term and long-term neuropsychological outcomes of youth sports-related concussions

“…Several studies indicate that possession of at least one APOE ε4 allele is associated with poorer cognition and lasting neuropsychological impairment after concussion in professional American football players, 96 boxers 95 and other adults, 97-100 although other studies found no such association. 101,102 Some evidence points to polymorphisms in both the APOE gene and its promoter as contributory factors to concussion risk in college athletes. 103,104 Another study did not identify a role for APOE ε4 in concussion risk, 105 although this allele might increase the risk of dementia following midlife or late-life mTBI.…”

Neuropsychology and clinical neuroscience of persistent post-concussive syndrome

“…Thus, some refer to PCS if the symptoms persist for more than a few days and in particular, if the symptoms persist for more than a week Sheedy et al, 2006). If the symptoms last more than 3 months then the term persistent post-concussive syndrome or PPCS has been used (Begaz et al, 2006;Chamelian et al, 2004;Iverson, 2006;Rees, 2003;Satz et al, 1999;Stalnacke et al, 2005;Willer & Leddy, 2006). Whereas there is a relationship between severity of concussion and who develops PPCS (Hessen et al, 2006), concussion severity by itself is a poor predictor of who develops PPCS (Guskiewicz et al, 2004).…”