Doc, you know my hands seem to tingle an awful lot. And you know, so do my feet. It is like they are asleep or something. Any idea what that is?
So, the sense of tingling is called parasthesia, and might represent any number of things. It usually represents an irritation or inflammation of a nerve, such as when your legs fall asleep while sitting cross legged. Sometimes it feels like tingling, and sometimes it feels like a burning. The pattern or the tingling, the characteristics of the tingling and the presence or absence of weakness help us figure out the cause.
What kind of things may make this happen? There are lots of causes of peripheral neuropathy. This can range from trauma, infection, or endocrine problems. Trauma (chronic or acute) can lead to trapping of nerves that causes chronic irritation, inflammation and may lead to neuropathy. Carpal tunnel syndrome is the classic example of this kind of problem. This could also be due to problems with diabetes or thyroid dysfunction. Nutritional deficiencies also account for some of the cases, usually due to problems with B12 absorption as seen in patients with celiac disease, renal disease, or liver disease (Lancet 2004 Jun 26;363(9427):2151). In these instances, the irritation/inflammation of the nerves is as a consequence of the disease progress. There are also other causes (such as infections), from medications (alcohol, chemotherapy drugs, and others), or from toxins (arsenic, mercury, cyanide and such).
Ok, so how do I figure out if I have this problem or not? This is pretty straight forward for us. The first step is a good history and a thorough physical examination. Often these two steps will do a great deal to help figure out what is going on. The history and physical will help us narrow down the likelihood of peripheral neuropathy and point us in the direction of the tests that will need to be considered to determine the cause. The American Academy of Neurology has laid out a straight forward stepwise evaluation of peripheral neuropathy (Neurology 2009 Jan 13;72(2):185). The basic screening tests include a test for diabetes, B12 deficiency and serum protein immunofixation electrophoresis. Additionally, testing the nerves themselves using a nerve conduction test is usually performed (Neurology 2003 Mar 25;60(6):898).
OK so if I have this, what do I need to do to treat it? Well, this is a case of prevention being far better than treatment. First off, activity is not likely to make things worse and helps people maintain strength (Cochrane Database 2004 Oct 18;(4):CD003904). For patients who have pain as the main symptom of their unhappy nerves, then there are several medications that have been shown to help with the control of the pain. Narcotics (such as morphine and such) have been shown to decrease the pain from neuropathy (Cochrane Database Systemic Review 2006 Jul 19;3:CD006146). Additionally, there are some older antidepressant medications are helpful in decreasing the pain from neuropathy (Neurology 2003 Apr 22;60(8):1284). Of course, if the cause is vitamin deficiency then treating that deficiency will help correct the neuropathy.
Where can I get some more information?
The National Institute of Neurological Disorders and Stroke has lots of information here.
MedlinePlus also has a lot of good information.