Neuropathy comes with a wide range of different symptoms, with almost all parts of the body able to be affected by it in some way or another. The two types of neuropathy: peripheral neuropathy and cranial neuropathy, cause their own distinct types of symptoms, some of which are described below.
Peripheral neuropathy tends to affect a wider area of the body than cranial neuropathy. Common sensory symptoms present in many types of neuropathy include pain, itching, ‘pins and needles’. Sufferers also commonly experience loss of function symptoms, such as numbness and tremor. Pain can range from mild to intense, with drugs often being required to help with this. Hypersensitivity to touch is also a frequent occurrence, with patients not able to have any material touching certain parts of their bodies. Most often it is the feet that are affected by this problem, resulting in the sufferer being unable to wear socks or shoes, and even finding some surfaces problematic to walk on. This results in the sufferers eventually being unable to leave the house in extreme cases.
In terms of motor function, patients can experience a range of symptoms from weakness and tiredness to muscle cramps and twitches (known as fasciculation). Fasciculations are usually harmless, however they can be an indicator of a disease of the motor neurons. Inflammation of affected areas can also be present. Particularly in polyneuropathy, the problems can lead to dizziness upon standing, and problems such as erectile and urinary dysfunction. Hypoglycemia can also occur.
Cranial neuropathy is split into two smaller sets of problems: optic neuropathy and auditory neuropathy.
The main symptom of optic neuropathy is partial or full blindness, depending on the severity of the condition. This may affect one or both eyes, with or without pain. Also possible is the loss of color vision in one or both eyes – either totally, or colors simply becoming blurred or washed out. Also, some colours may turn into other colours, for example a patient may look at a lump of butter that, to them, appears to be pink. The loss of color vision may not even be noticed by the patient until examined by a doctor; if the patient has lost the ability to see color in only one eye, the other eye compensates so that proper color vision is maintained.
Auditory neuropathy, on the other hand, has the main symptom of partial or full deafness. This can be in one ear or both, with the degree of deafness in each ear not necessarily being the same if both ears are affected. This can cause a lot of discomfort to the patient because the brain cannot properly detect where noise or sound is coming from, leading to unpleasant confusion. The deafness can come either over a prolonged period of time, or sometimes can happen instantly. The problems can come about completely spontaneously in some cases, or they may go hand in hand with other illnesses such as Friedreich’s ataxia.