Final answer:
The 47-year-old woman with muscle weakness and reflexes present in the left limbs after a right-sided stroke has upper motor neuron damage. Upper motor neuron lesions are indicated by these symptoms, along with muscle tone despite the inability to move voluntarily.
Step-by-step explanation:
The symptoms described in the scenario provided for the 47-year-old woman, including weakness and loss of sensation in the left arm and leg, reflexes being present, and the location of the cerebral vascular accident (CVA) on the right side, indicate that this is a case of upper motor neuron damage. Upper motor neurons (UMNs) originate in the brain and carry motor information down to the final common pathway where they connect with lower motor neurons (LMNs), which then carry the signals to the muscles.
Signs of UMN lesion typically include muscle weakness, strong deep tendon reflexes, and spasticity, which is a form of muscle tone. Since the patient can still display reflexes and has muscle tone, despite the inability to move the limbs voluntarily, it suggests that the muscles and their LMN connections are intact; however, the damage is in the UMNs, which are responsible for voluntary movements and coordination. Spasticity is also a common feature of UMN lesions, contributing to the presence of muscle tone observed in the patient.
An MRI confirmed the stroke in the right hemisphere, which controls the left side of the body, providing further evidence that the neurological deficit observed is consistent with UMN damage, since the affected limbs are contralateral to the side of the brain that the stroke occurred on.