Differentiating Central vs Peripheral Lesion in Acute Flaccid Paralysis of the Lower Limbs

Abstract

Differentiating upper motor neuron (UMN) from lower motor neuron (LMN) lesions is essential in the evaluation of acute flaccid paralysis, as it directs diagnosis and management. This report discusses two cases highlighting the challenges of neurological localisation. The first case presented with bilateral lower limb weakness, hypotonia, and diminished reflexes, suggesting an LMN lesion. However, urinary retention and sensory level below T6 indicated spinal cord involvement, leading to an initial diagnosis of transverse myelitis, which was later revised to acute disseminated encephalomyelitis (ADEM) due to altered sensorium and multifocal brain and spinal cord lesions. The second case, with ascending weakness and ankle areflexia, was diagnosed with Guillain–Barré syndrome (GBS). These cases highlight the importance of clinical features such as reflex patterns, sensory loss, and bladder involvement in distinguishing central from peripheral nervous system pathologies.