Acute hemiparesis as the initial manifestation of Chiari I-associated syringomyelia: a stroke mimic

Abstract

Introduction: Syringomyelia is a rare neurological disorder characterised by the formation of a fluid-filled cystic cavity (syrinx) within the spinal cord, most commonly resulting from disruption of cerebrospinal fluid flow. It typically presents as slowly progressive dissociated sensory loss in a cape-like distribution involving bilateral shoulders, upper back, neck and arms, and is often accompanied by muscle weakness. Case description: A 44-year-old female presented with sudden-onset posterior headache followed by right-sided blurred vision, right-sided hemiparesis along with numbness and paraesthesia. The initial evaluation ruled out a stroke. Magnetic resonance imaging (MRI) of the brain and spinal cord revealed an Arnold Chiari-I malformation with an extensive multiseptate syrinx from the cervical spinal cord to the conus medullaris. Multiple teleneurology consultations with multiple repeat imaging failed to elucidate the cause of the patient’s progressive symptoms. Persistent and progressive neurological deterioration prompted a transfer for an in-person neurology evaluation where the definitive diagnosis was made, resulting in urgent transfer to a tertiary level centre for emergent posterior fossa decompression. Conclusion: This case highlights an unusual presentation of syringomyelia with acute, rapidly progressive unilateral neurological deficits without an identifiable precipitating event, closely mimicking acute ischaemic stroke. It emphasises the need to maintain a broad differential diagnosis when the presentation is atypical, or investigations do not explain the neurological deficits. This case also underscores the importance of comprehensive bedside neurological examination, as reliance on teleneurology may delay diagnosis. Early recognition and timely neurosurgical intervention can result in substantial neurological recovery.