A 58-year-old woman comes to the physician because of a 1-week history of episodes of involuntary rhythmic jerking movements of her left arm and hand. Neurologic examination shows a brisk biceps reflex on the left. A Babinski sign is present on the left. MRI of the head shows a 1-cm, round, ring-enhancing lesion. She was diagnosed with HIV 5 years ago. Her current medications are triple-antiretroviral therapy and trimethoprim/sulfamethoxazole. Which of the following is the most likely explanation for this patient’s presentation?
Cryptococcus neoformans
Cryptosporidium parvum
Malignancy
Taenia solium
Toxoplasma gondii
