<prompt> A patient presents with recurrent optic neuritis of both eyes with extensive transverse myelitis. Visual acuity in right eye is 660 and visual acuity in left eye is 618. Patient showed 50 response to steroids. Diagnosis is:Neuromyelitis optica NMOSubacute combined degeneration of spinal cord SACDPosterior cerebral artery strokeNeurosyphilis  <response>: Ans. A. Neuromyelitis optica NMO Clinical scenario matches classic Wingerchuk criteria. Optic neuritis simultaneous transverse myelitis. So it is a case of neuromyelitis optica.Diagnostic Criteria for NMO Required:- Optic neuritis- Acute transverse myelitis Supportive 2 of 3 criteria required:- Longitudinally extensive cord lesion extending over 3 or more vertebral segments- Brain magnetic resonance imaging normal or not meeting criteria for multiple sclerosis- Aquaporin-4 seropositivity- Cloud-like appearance sometimes seen in MRI- CSF findings: Pleocytosis, neutrophils, and eosinophils- Next investigation will be Anti NMO IgG in blood CSF- Best treatment: Steroids IV IgSubacute Combined Degeneration of Spinal Cord Loss of reflexes due to an associated peripheral neuropathy Diagnostic clue: Babinski sign Optic atrophy and irritability seen in advanced cases Lab findings: Macrocytic red blood cell, low serum B12 concentration, elevated serum homocysteine Best investigation: Antiparietal cell antibodies and Schilling test Treatment: Vitamin B12 therapy 1000 pg given intramuscular at regular intervalsNeurosyphilis Neurological involvement: Argyll-Robertson pupil, Tabes dorsalis, general paresis, rarely a gumma or aortitis. Initial diagnostic test:- Lumbar puncture for neurosyphilisFTA is 100 sensitive in CSFCSF VDRL is only 50 sensitive Treatment: IV penicillin. Desensitize if the patient is penicillin allergic. 