Limb-kinetic apraxia in a patient with mild traumatic brain injury: A case report

RATIONALE: We report on a patient who developed limb-kinetic apraxia (LKA) due to an injured corticofugal tract (CFT) from the secondary motor area following mild traumatic brain injury (TBI), demonstrated on diffusion tensor tractography (DTT). PATIENT CONCERNS: She was struck in the right leg by a sedan at a crosswalk and fell to the ground. She lost consciousness and experienced post-traumatic amnesia for approximately ten minutes. She was obliged to wear a cast for a left humerus fracture for two months, and she found she could not move her left hand quickly with intention after removal of the cast; consequently her left hand was almost non-functional. When she visited the rehabilitation department of a university hospital two years after the crash, she had mild weakness of the left upper extremity (manual muscle test: 4/5). However, the movements of the left hand were slow, clumsy, and mutilated when executing grasp-release movements of her left hand. DIAGNOSES: A 44-year-old female suffered head trauma resulting from a pedestrian car accident. INTERVENTIONS: When she extended all her left fingers, it took approximately eight seconds at her fastest speed to perform the pattern extending from the thumb to little finger sequentially. OUTCOMES: On two-year DTT, narrowing and partial tearing was observed in the right supplementary motor area (SMA)-CFT. LESSONS: Injury of the right SMA-CFT was demonstrated in a patient with LKA in a hand following mild TBI. Our results stress the need to evaluate the CFTs from the secondary motor area for patients with unexplained motor execution problems following mild TBI.