Abstract
Isolated foot drop is a neurological sign frequently linked to lower motor neuron (LMN) lesions, including peroneal nerve damage or L4-L5 radiculopathy. Nonetheless, upper motor neuron (UMN) lesions, such as strokes or tumors located in the parasagittal motor cortex, may sometimes manifest as isolated foot drops. The main causes of isolated foot drop secondary to central etiologies are uncommon, with few instances documented in the literature. An 83-year-old male presented with a four-day history of left isolated foot drop that started in the big toe and then spread to involve the whole foot. Clinical examination was negative for any other neurological deficit. Magnetic resonance imaging (MRI) of the cervical, thoracic, and lumbar spine showed only mild lumbar spinal stenosis at the L4/L5 level. Brain MRI revealed acute infarction foci in the right superior frontal gyrus. While uncommon, central causes of isolated foot drop should be taken into account when peripheral examinations yield inconclusive results. This case highlights the significance of a thorough diagnostic method, encompassing brain imaging, to detect lesions in the central nervous system. Timely identification and management of these cases are essential for enhancing patient outcomes and avoiding misdiagnosis.