The most useful test in further evaluating this patient would be an MRI of the brain. An MRI (Magnetic Resonance Imaging) of the brain can provide detailed images of the brain
structures, allowing the healthcare provider to assess for any abnormalities that could be causing the patient's symptoms. In this case, the patient is presenting with weakness, visual loss, and sensory loss over the right great toe, which suggests a neurological issue.
An MRI of the brain can help identify any
lesions or abnormalities in the brain that may be responsible for the patient's symptoms. It can help rule out conditions such as multiple sclerosis, which can cause episodic neurological symptoms like the ones described by the patient.
The other options listed - Electromyograph, Glucose tolerance test, and Electroencephalograph - may be useful in other clinical scenarios but are not the most appropriate tests for evaluating the specific symptoms presented by this patient. Remember, it is important to consult with a healthcare professional for a definitive diagnosis and appropriate treatment.