Q. A 37-year-old male presents to your clinic with a sudden onset of weakness in his legs that progressed to involve his arms over the course of a week. He reports difficulty walking and performing fine motor tasks, such as buttoning his shirt. The patient had no history of significant medical problems, but does report a recent upper respiratory infection two weeks prior to the onset of his symptoms. Physical examination reveals symmetrical weakness in all extremities, with the greatest weakness noted in his legs. Deep tendon reflexes are absent and the patient is unable to perform a heel-to-shin test due to difficulty coordinating the movement. Sensory examination is normal. You order laboratory studies, including a complete blood count, electrolyte panel, and serum protein electrophoresis, which are all within normal limits. Nerve conduction studies show evidence of demyelination and an elevated cerebrospinal fluid protein level. You initiate treatment with intravenous immunoglobulin and monitor the patient closely for any signs of respiratory failure. Over the course of the next two weeks, the patient’s weakness gradually improves and he is eventually able to walk with assistance. Which of the following is NOT true regarding this patient’s most likely diagnosis?