Background: Although neurological conditions present with specific clinical patterns, practitioners often encounter patients with vague symptom complexes. Delayed diagnosis and unnecessary medications can lead to iatrogenic effects and poor prognosis. Case Report: This paper reports a 21-year-old girl who perceived right upper extremity monoplegia following a trauma, which did not fit into the traditional neurological diagnosis. Her movement patterns during physiotherapy were suggestive of the central fatigue related reduction of function. Focused behavioral neuro-rehabilitation approach based training helped her to regain her upper extremity function. Conclusion: Central fatigue may be considered as a differential diagnosis when atypical muscle weakness occurs following a probable physical exertion.