Hypoesthesia

Hypoesthesia is a medical term for numbness. It describes a reduced sense of touch or sensation. A person might experience a partial loss of sensitivity to sensory stimuli. In everyday speech, most people simply call this feeling numbness. This condition is a common side effect of many different medical issues. It matters because it signals that something is wrong with how the body processes touch. Understanding hypoesthesia helps doctors identify underlying problems in the nervous system or blood supply.

This sensation usually happens because of damage to the nerves. It can also occur when blood vessels become blocked. A blockage causes ischemic damage to the tissues that the vessels supply. Ischemic damage happens when tissues do not get enough blood. When this occurs, the body cannot send touch signals correctly. Doctors can detect this type of damage using various imaging studies. These studies allow medical professionals to see exactly where the disruption is happening.

There are many specific conditions that cause hypoesthesia. Decompression sickness is one example. This occurs during a rapid ascent of 20 feet or more, usually from underwater. During this process, air bubbles form in the blood. These bubbles prevent oxygen from reaching downstream tissue. Another cause is a trigeminal schwannoma. This is a tumor that grows on the trigeminal nerve, also known as cranial nerve five. The tumor blocks the nerve from sending signals. This results in numbness in the area the nerve controls, which is the face.

Other serious illnesses also lead to sensory loss. Rhombencephalitis is a bacterial invasion of the brainstem and the trigeminal nerve. This infection can cause facial hypoesthesia in the V1 through V3 dermatomes. A different condition is called Intradural extramedullary tuberculoma of the spinal cord, or IETSC. IETSC is a cancer of the spinal cord. It causes a total lack of feeling in all body parts associated with the affected spinal nerves. This happens because the body cannot convey information from the body to the central nervous system.

Some conditions affect the skin or nutrition directly. Cutaneous sensory disorder, or CSD, is associated with negative sensory symptoms. Patients with CSD may feel disagreeable skin sensations. These can include stinging, itching, or burning due to increased nervous system activity. They can also include numbness due to decreased activity. Beriberi is another condition caused by a thiamine deficiency. This can cause hypoesthesia that starts in the feet, fingers, navel, or lips. The numbness can then extend centrally from those areas.

To find the cause, doctors follow a specific diagnostic process. They often start by asking a series of questions. They want to pinpoint the exact location and severity of the numbness. A physical examination may follow. During this exam, a doctor might tap lightly on the skin. They want to see how much feeling is present. Doctors may then recommend specialized tests. These include computerized axial tomography (CT) and magnetic resonance imaging (MRI) scans. They may also use nerve conduction studies to measure electrical impulses in the nerves.

Doctors also use reflex tests to check the nervous system. An example of this is the patellar reflex test. Treatment for hypoesthesia focuses on the broader illness causing it. For decompression sickness, hyperbaric oxygen is used. This involves breathing oxygen at a level of 100% to maintain stability. For rhombencephalitis, doctors use antibiotics like ampicillin to remove bacteria. For trigeminal schwannoma, excision is the only effective treatment. However, surgery might not fix the numbness if the nerve was already damaged.