Intelligence after traumatic brain injury: meta-analysis of outcomes and prognosis – Konigs,
Engenhorst & Oosterlaan (2015)
Abstract
In conclusion, TBI causes persisting intelligence impairments, where children may have better
recovery from mild TBI and poorer recovery from severe TBI than adults. Injury severity measures
predict intelligence impairments and do not outperform one another.
Survivors of TBI often have impaired neurocognitive functions, prominently manifested in
intelligence. In children, the impact of TBI is thought to slow down post-injury development of
intelligence, which may translate into increasing intellectual delays. Intelligence impairments in
children with TBI have in turn been associated with psychiatric symptoms and poor academic
attainment. In adults with TBI, intelligence impairments relate to psychopathology, poor vocational
placement and lower quality of life. These findings highlight intelligence as a crucial factor in the
prognosis of TBI.
(PTA) = Post-traumatic amnesia
This study is the first to comprehensively quantify the impact of mild, moderate and severe TBI on
intelligence in children and adults, and to determine the prognostic value of age at injury and injury
severity using meta-analytic methods.
GSC score:
- Mild TBI 15-13
- Moderate TBI 12-9
- Severe TBI 8-3
PTA duration:
- < 1 day
- 1-7 days
- > 7 days
Subacute phase TPI ≤ 6 months
Chronic phase > 6 months
Mild TBI
Patients with mild TBI had no significant intelligence impairments in the subacute phase of recovery,
but there were significant smallsized FSIQ and VIQ impairments in the chronic phase. There were no
significant differences between the subacute phase of recovery and the chronic phase in the effects
of mild TBI on any of the IQ indices, and the VIQ impairment in the chronic phase did not differ from
the PIQ impairment.
Moderate TBI
TBI on intelligence showed low heterogeneity. Patients with moderate TBI had significant medium-
sized FSIQ and PIQ impairments and a small VIQ impairment in the subacute phase of recovery. In
the chronic phase, significant small-sized FSIQ and VIQ impairments were found, but no impairment
in PIQ was observed. The FSIQ and PIQ impairments were smaller in the chronic phase compared to
the subacute phase.
Severe TBI
Moderate to high heterogeneity was found in metaanalytic effect sizes reflecting the impact of
severe TBI on intelligence. Patients with severe TBI exhibited significant large-sized FSIQ, PIQ and VIQ
impairments in the subacute phase of recovery. In the chronic phase, severe TBI patients showed
Engenhorst & Oosterlaan (2015)
Abstract
In conclusion, TBI causes persisting intelligence impairments, where children may have better
recovery from mild TBI and poorer recovery from severe TBI than adults. Injury severity measures
predict intelligence impairments and do not outperform one another.
Survivors of TBI often have impaired neurocognitive functions, prominently manifested in
intelligence. In children, the impact of TBI is thought to slow down post-injury development of
intelligence, which may translate into increasing intellectual delays. Intelligence impairments in
children with TBI have in turn been associated with psychiatric symptoms and poor academic
attainment. In adults with TBI, intelligence impairments relate to psychopathology, poor vocational
placement and lower quality of life. These findings highlight intelligence as a crucial factor in the
prognosis of TBI.
(PTA) = Post-traumatic amnesia
This study is the first to comprehensively quantify the impact of mild, moderate and severe TBI on
intelligence in children and adults, and to determine the prognostic value of age at injury and injury
severity using meta-analytic methods.
GSC score:
- Mild TBI 15-13
- Moderate TBI 12-9
- Severe TBI 8-3
PTA duration:
- < 1 day
- 1-7 days
- > 7 days
Subacute phase TPI ≤ 6 months
Chronic phase > 6 months
Mild TBI
Patients with mild TBI had no significant intelligence impairments in the subacute phase of recovery,
but there were significant smallsized FSIQ and VIQ impairments in the chronic phase. There were no
significant differences between the subacute phase of recovery and the chronic phase in the effects
of mild TBI on any of the IQ indices, and the VIQ impairment in the chronic phase did not differ from
the PIQ impairment.
Moderate TBI
TBI on intelligence showed low heterogeneity. Patients with moderate TBI had significant medium-
sized FSIQ and PIQ impairments and a small VIQ impairment in the subacute phase of recovery. In
the chronic phase, significant small-sized FSIQ and VIQ impairments were found, but no impairment
in PIQ was observed. The FSIQ and PIQ impairments were smaller in the chronic phase compared to
the subacute phase.
Severe TBI
Moderate to high heterogeneity was found in metaanalytic effect sizes reflecting the impact of
severe TBI on intelligence. Patients with severe TBI exhibited significant large-sized FSIQ, PIQ and VIQ
impairments in the subacute phase of recovery. In the chronic phase, severe TBI patients showed
