What is main difference between symptoms and diagnosis of asymptomatic neurosyphilis and TB meningitis? Can one be misdiagnosed as other?

Big difference. Neurosyphilis is usually slow in onset and causes balance problems and dementia-like symptoms. Tb meningitis comes on more quickly and tends to cause double vision or numbness on the face, trouble talking, confusion or stroke-like symptoms. A spinal tap is the best way to make the diagnosis of either test. There is a blood test to look for a syphilis infection.