Cortical shoulder syndrome: isolated shoulder weakness from a small cortical infarct

A 62-year-old man with multiple vascular risk factors developed acute-onset altered sensation in the right arm and lateral shoulder, followed by isolated shoulder abduction weakness. While there was initial uncertainty in localisation as to a central or peripheral lesion, the sensory pattern was atypical for a peripheral nerve lesion. An MR scan of the brain confirmed a small area of acute cortical infarction affecting primary motor and sensory regions along the banks of the precentral sulcus. This unusual stroke syndrome (‘cortical shoulder syndrome) not only illustrates principles of clinical neuroanatomical localisation but may also be of practical importance to aid timely and appropriate acute ischaemic stroke diagnosis and treatment.