Nerves are wonderful things. Some of them are the longest cells in the body, extending from the lumbar spine to the foot. And the whole nervous system is a vast network, like a hugely complex telephone exchange.
But sometimes something goes wrong with the cables. In multiple sclerosis, for instance, the insulation around the wires breaks down. Bell’s palsy is another example, a facial paralysis that can affect any age group and frequently responds to treatment or comes right by itself.
And if the nerve itself begins to generate electric impulses, instead of just transmitting them, you get the neuralgias. In general practice we see these often. Post-shingles neuralgia can be a horrible thing, and preventing it is a major thrust of a current vaccination programme. For the first time this year, the government is funding the shingles vaccine for people aged 65-80 years and demand has been so high that we ran out for a while. I would encourage everybody in that age group to consider having the shot.
Then there is a mysterious condition called trigeminal neuralgia. The trigeminal nerve serves the chewing muscles and receives sensation from the face. Nobody really knows what causes trigeminal neuralgia, but there might be some sort of vascular problem or injury that causes acute stabbing pains to occur at random intervals. This very unpleasant malady, if untreated, can lead to great distress and depression. Fortunately it is responsive to medications. Our mainstays would be the tricyclic antidepressants, which at low doses are pain modulaters, or Gabapentin, originally developed as an epilepsy drug.
Another common condition is peripheral neuropathy. This is a malfunction in the nerves to the lower legs, producing a kind of “static” on the telephone line. Patients variously report burning discomfort, pain, numbness, pins and needles or a wooden feeling. It can be progressive, starting at the toes and moving north steadily. There are some recognised causes, notably diabetes and some vitamin deficiencies, but often we have to pull out the term ‘idiopathic’, which is a way of saying we haven’t got a clue. It’s one of the “rewards for maturity”, mostly affecting people over 55 years. Usually the diagnosis is pretty clear-cut, but it might be necessary to do nerve conduction studies to be sure. Peripheral neuropathy is moderately treatable with medication but I can’t say it reflects the finest achievement in medical science. It’s definitely worth a consultation, though.