Dymowski et al.

(2017)

Australia

RCT

PEDro=9

N_Initial=11, N_Final=10

Population: TBI. Methylphenidate Group (n=6): Mean Age=35 yr; Gender: Male=4, Female=2; Mean Time Post Injury=366 d; Mean Worst GCS=4.83. Placebo Group (n=4): Mean Age=32.5 yr; Gender: Male=2, Female=2; Mean Time Post Injury=183.5 d; Mean Worst GCS=4.50.

Treatment: Participants were randomly assigned to receive either methylphenidate (0.6 mg/kg/d rounded to the nearest 5mg with maximum daily dose of 60 mg) or placebo (lactose). Outcomes relating to processing speed, complex attentional functioning, and everyday attentional behaviour were assessed at baseline, 7-wk (on-drug), 8-wk (off-drug), and 9-mo follow-up.

Outcome Measures: Symbol Digit Modalities Test (SDMT), Trail Making Test (TMT) A and B; Hayling (A, B, error),  Digit Span (DS-Forward, Backward, Sequencing, Total), Ruff 2&7 Selective Attention Test Automatic Speed Raw Score (2&7 ASRS), Ruff 2&7 Selective Attention Test Controlled Speed Raw Score (2&7 CSRS), Simple Selective Attention Task Reaction Time (SSAT RT), Complex Selective Attention Task Reaction Time (CSAT RT), N-back 0-back RT, N-back 1-back RT, N-back 2-back RT, Rating Scale of Attentional Behaviour Significant Other (RSAB SO).

Plenger et al.

(1996)

USA

RCT

PEDro=5

N=23

Population: TBI; Gender: Male=17, Female=6; Placebo Group (n=13): Mean Age=26.6 yr; Mean GCS=8.1; Methylphenidate Group (n=10): Mean Age=31.4 yr; Mean GCS=9.3.

Intervention: Patients were randomly allocated to receive either methylphenidate or placebo. Methylphenidate was administered at 30 mg/kg, 2 ×/d, for 30 d.

Outcome Measures: Disability Rating Scale (DRS), Continuous Performance Test (CPT), 2 & 7 Test (2 & 7), Paced Auditory Serial Addition Test (PASAT), Digit Span & Attention/ Concentration from Wechsler Memory Scale-Revised (Attn/Conc from WMS-R).

1.        At 30 d follow-up (n=15), significant differences were obtained on DRS, suggesting better outcome for the methylphenidate group. This difference however was not seen at 90d follow-up (n=11).

2.        Significant differences were found on the attention-concentration domain at the 30d follow-up, as indicated by CPT, PASAT, 2 & 7, and Attn/Conc from WMS-R (p<0.030). The treatment group performed better in these measures compared to the placebo group.

Speech et al.

(1993)

USA

RCT

PEDro=7

N=12

Population: TBI; Mean Age=27.6 yr; Gender: Male=5, Female=7; Mean Time Post Injury=48.5 mo.

Intervention: In a crossover design, participants were randomly assigned to receive 0.3 mg/kg methylphenidate, 2 ×/d, for 1-wk, followed by 1-wk of placebo, or receive the treatment in a reverse order.

Outcome Measures: Gordon Diagnostic System, Digit Symbol and Digit Span subtests of the Wechsler Adult Intelligence Scale-Revised, Stroop Interference Task, Sternberg High Speed Scanning Task, Selective Reminding Test, Serial Digit Test,

++ Katz Adjustment Scale.

Gualtieri & Evans

(1988)

United States

RCT Crossover

PEDro=7

N=15

Population: Mean age=24.1yr; Gender: Male=10, Female=5; Mean time post-injury=46.8mo.

Intervention: Participants were assigned to receive three conditions in randomized order. 1) Placebo; 2) Methylphenidate (0.15mg/kg) twice daily; 3) Methylphenidate (0.30mg/kg) twice daily. Each condition was 12 days long, with 2 days washout between conditions.

Outcomes: Adult Activity Scale self-administered (AAS-S), Adult Activity Scale (administrator)(AAS-O), Examiner’s Rating Scale (EXRS), Self-Rating Scale (SRS), Verbal Fluency Test (VFT), Non-verbal Fluency test (NVFT).

1.        There was a significant improvement in AAS-S and AAS-O scores between the placebo and high-dose conditions (p<0.05).

2.        There was a significant difference in SRS scores between the placebo group and the high-dose condition (p<0.05).

3.        On the EXRS there was a significant difference between baseline and low-dose (p=0.012), placebo and low-dose (p=0.025), baseline and high-dose (p=0.012), with higher doses of methylphenidate having improved effects.

4.        There was a significant improvement in VFT scores between baseline and the high-dose groups (p=0.017).

5.        There was a significant difference on NVFT scores between baseline and placebo (p=0.008), baseline and low-dose (p=0.008), baseline and high-dose (p=0.008), and the placebo and high-dose group (p=0.018), with methylphenidate improving scores.