Proximal weakness due to injury of the corticoreticular pathway in a patient with traumatic brain injury

Abstract

The corticoreticular pathway (CRP) innervates the proximal muscles of extremities and axial muscles; therefore, it is involved in postural control and gait. We report on a patient who exhibited proximal weakness due to a CRP injury, which was evaluated using diffusion tensor tractography (DTT). A 62-year-old male patient who had been injured in a traffic accident underwent conservative management for a contusional hemorrhage in the right frontotemporal lobes, and a subdural and epidural hematoma in the right temporoparietal lobes. The patient exhibited right proximal weakness (shoulder: 3+, hip: 3+) at two weeks after onset. Findings on brain MRI revealed encephalomalactic lesions in both frontal lobes. Findings on DTT of the left CRP showed discontinuation at the midbrain level; in contrast, the integrities of the corticospinal tract in both hemispheres were maintained from the cerebral cortex to the medulla along the known pathway of the corticospinal tract. The proximal weakness of the right shoulder and hip observed in this patient appeared to be attributed to injury of the left CRP.