NEFL and Guillain-Barre syndrome, familial: While earlier studies suggested that patients with AMAN experience a worse prognosis compared with those with AIDP (12, 27), more recent research indicates that other factors such as baseline severity of weakness, as measured by Medical Research Council (MRC) scale sum score, and serum and cerebrospinal fluid (CSF) neurofilament light chain (NfL) and neurofilament heavy chain levels during active disease are more relevant in predicting outcome in patients with GBS (12, 44–48).