hi, as you mentioned about the symptoms of numbness you need to be little slow in first getting what the cause is. as the medical fraternity is trying to figure out the cause. also, The CNS has two kinds of tissue: grey matter and white matter, Grey matter, which has a pinkish-grey color in the living brain, contains the cell bodies, dendrites and axon terminals of neurons, so it is where all synapses are. White matter is made of axons connecting different parts of grey matter to each other. now as you said the spinal tap test is done you need to wait and see the reports. the numbness can also be because of the lumbar spine issue. which has to be ruled out. an MRI will put the insight to the matter. most of the time, we have to wait for any other symptoms to arise, as most symptoms are self limiting and are not a major cause. So rather getting panic you should just stay calm. Also you can perfrom regular meditation and breathing exercises with general physical exercise as it will keep you out of stress and tension. with the grace of God I wish you a speedy recovery Regards Jay Indravadan Patel