Objective: Prolonged mental fatigue and cognitive impairments are common after a mild traumatic brain injury (TBI). This sets limits for rehabilitation and for regaining the capacity for work and participation in social life.
Method: This follow-up study, over a period of approximately 5.5 years was designed to evaluate the effect and safety of methylphenidate treatment for mental fatigue after a mild TBI. A comparison was made between those who had continued, and those who had discontinued the treatment. The effect was also evaluated after a four-week treatment break.
Results: Significant improvement in mental fatigue, depression, and anxiety for the group treated with methylphenidate (p < .001) was found, while no significant change was found for the group without methylphenidate. The methylphenidate treatment group also improved their processing speed (p = .008). Withdrawal produced a pronounced and significant deterioration in mental fatigue, depression, and anxiety and a slower processing speed. This indicates that the methylphenidate effect is reversible if discontinued and that continued methylphenidate treatment can be a prerequisite for long-term improvement. The effect was found to be stable and safe over the years.
Conclusion: We suggest methylphenidate to be a possible treatment option for patients with post-TBI symptoms including mental fatigue and cognitive symptoms.
Long-term mental fatigue and cognitive impairment are common after a mild, moderate or severe traumatic brain injury (TBI) and these can have a significant impact on work, well-being and quality of life (1). Fatigue and concentration deficits are acknowledged as being one of the most distressing and long-lasting symptoms following mild TBI (1). There is currently no approved treatment (2), although the most widely used research drug for cognitive impairments after TBI is methylphenidate (3). A few studies have used methylphenidate for mental fatigue after TBI with promising results including our own (4,5). Other clinical trials of drugs have reported improvements in mental fatigue ((−)-osu6162 (6)) or none ((−)-osu616, modafinil (7–9)).
In our feasibility study of methylphenidate (not placebo controlled) we reported decreased mental fatigue, improved processing speed and enhanced well-being with a “normal” dose of methylphenidate compared to no methylphenidate for people suffering from post-traumatic brain injury symptoms (4). We tested methylphenidate in two different dosages and found that the higher dose (20 mg three times/day) had the better effect compared to the lower dose. We also found methylphenidate to be well tolerated by 80% of the participants. Adverse events were reported as mild and the most commonly reported side-effects included restlessness, anxiety, headache, and increased heart rate; no dependence or misuse were detected (10). However, a careful monitoring for adverse effects is needed, as many patients with TBI are sensitive to psychotropic medications (11).
Participants who experienced a positive effect with methylphenidate were allowed to continue the treatment. We have reported the long-term positive effects on mental fatigue and processing speed after 6 months (12) and 2 years (13). No serious adverse events were reported (13)(Figure 1). In a 30-week double-blind-randomized placebo-controlled trial, Zhang et al. reported that methylphenidate decreased mental fatigue and improved cognitive function in the participants who had suffered a TBI. Moreover, social and rehabilitation capacity and well-being were improved (5). Other studies evaluating methylphenidate treatment after TBI have focused only on cognitive function reporting improved cognitive function with faster information processing speed and enhanced working memory and attention span (14–21). A single dose of methylphenidate improved cognitive function and brain functionality compared to placebo in participants suffering from post-TBI symptoms (22,23). Most of these have been short-term studies covering a period between 1 day and 6 weeks and included participants suffering from mild or more severe brain injuries.
This clinical follow-up study was designed to evaluate the long-term effect and safety of methylphenidate treatment. We also evaluated the effect after a four-week treatment break and compared the subjective and objective effects with and without methylphenidate. Patients who had discontinued methylphenidate during this long-term study were also included in this follow-up, as it was our intention to compare the long-term effects on mental fatigue in patients with and without methylphenidate treatment.