What is Herniated Nucleus Pulposus?
Herniated nucleus pulposus or HNP is a medical term used to define a spinal condition commonly known as slipped disc or herniated disc.(1)
The human spine or the vertebral column is made up of 33 individual bones called as vertebra. These vertebrae have something called as spinal discs between them, which act as a shock absorber. Nucleus pulposus is a jelly like substance found within the spinal discs, within in hard outer wall. Due to wear and tear of these discs, the walls of the disc may develop a tear or break, leading to leakage of the nucleus pulposus from the disc into the spinal canal. This condition is known as herniated nucleus pulposus.
Herniated nucleus pulposus, is very common among today’s population. It is highly possible that a person may have this condition without him or her being aware about it. Symptoms are elucidated when the leakage of nucleus pulposus lead to compression of the nerves, ligaments and tissues; or disrupts the integrity of the spinal cord.
Signs and Symptoms of Herniated Nucleus Pulposus
Herniated nucleus pulposus does not give rise to symptoms by itself. Symptoms are felt, when the leakage of nucleus causes compression of nerves, which in turn leads to other serious issues. The most common symptoms associated with herniated nucleus pulposus are listed below:
- Pain and tenderness over the affected area
- Numbness and chronic discomfort
- Muscle weakness
- Loss of reflexes
- Pins and needle or tingling sensation
In some cases, nerve compress can lead to symptoms such as bowel and bladder incontinence with fever. This is considered as a medical emergency and needs urgent medical attention.
The symptoms of herniated nucleus pulposus are very similar to symptoms of other serious issues such as spinal stenosis, facet joint degeneration, cancer etc. Thus, it is very important to correctly diagnose the condition for providing correct treatment.
Causes of Herniated Nucleus Pulposus
As mentioned earlier, herniated nucleus pulposus is caused due to degeneration of the discs. This worsens with age due to increase in stress and strain over the spine.(1) However, it has been noted, certain factors aggravates this conditions. These common causes and listed below:
- Excessive weight gain or obesity
- Sedentary lifestyle with lack of physical activities or exercises
- Poor posture while lifting heavy objects
- High impact injury or sudden injury such as motor vehicle accident; fall from a height etc.
- Genetic inheritance or family history of spinal issue
- Occupational strain over the spine due standing, sitting or driving for extended period of time, manual labour, physical work etc.
- Excessive smoking or alcohol consumption
- Other underlying spine conditions or degenerative disc diseases.
Pathophysiology of Herniated Nucleus Pulposus
The pathophysiology of herniated nucleus pulposus is a combination of increase in local inflammatory chemokines and mechanical compression of nerves due to bulging of the nucleus pulposus. It has been noted that the incidence of herniation is more common in posterolateral area, due to the anatomy there (thin annulus fibrosus with poor support from anterior-posterior longitudinal ligaments). Posterolateral herniation may cause compression of the nerve root leading to radiculopathy. Spinal cord compression may cause myelopathy secondary to herniation of midline disc. Back pain is caused due to localized inflammation and herniated disc pressure over longitudinal ligament.
Diagnosis and Treatment of Herniated Nucleus Pulposus
Diagnosis of herniated nucleus pulposus is done by an experienced orthopedist. A detailed case history is obtained followed by physical examination of the back.
Confirmatory tests such as X-ray, MRI or CT scan are often helpful in ruling out other conditions and reaching a correct diagnosis.(1) Advanced technology such as pain mapping technologies are often used in these conditions. Based on the findings, treatment is planned. The available treatment options are:
Medications to Treat Herniated Nucleus Pulposus: A large number of over-the-counter medications are available in the market, for local application as well as for oral ingestion.(1) These medications control inflammation and pain, and it also helps in starting physical therapy without excessive discomfort. Prescription medications such as local injection of pain relieving agents are also available for severe cases. Some of these medications are effective for up to 6 months after a single shot.
Physical Therapy or Exercise for Herniated Nucleus Pulposus: Excessive bed rest in not beneficial for patients suffering from herniated nucleus pulposus. Physical therapy and specifically designed exercises, helps in combating this issue by strengthening abdominal muscles, increasing flexibility, losing excess pounds etc. They help is removing excess strain over the spine and promotes rapid healing,
Lifestyle Changes and Alternative Ways to Treat Herniated Nucleus Pulposus: Additional treatments such as lifestyle modification, ergonomic education, acupuncture, therapeutic massages, wearing appropriate footwear often help in management of the symptoms.
Surgical Intervention for Herniated Nucleus Pulposus: If conventional treatment does not relieve symptoms, surgical intervention is considered to treat herniated nucleus pulposus. Surgery aims at repairing the damages discs or replacing them with artificial spacers. Minimal invasive laparoscopic surgery is popularly used as a surgical option for herniated nucleus pulposus.
Complications of Herniated Nucleus Pulposus
The most common complication associated with herniated nucleus pulposus is compression of the entire cauda equine (i.e. the group of long nerve roots which branches out from the spinal cord below the waist neat the tail bone). This is an emergency situation and is associated with worsening of existing symptoms to the point where the patient is unable to carry out daily activities, bladder/bowel dysfunction, saddle anesthesia etc.
Prevention of Herniated Nucleus Pulposus
Following a few precautionary measures can help in reducing the risk of developing herniated disk. Some of these preventive measures include:
- Being physically active and exercising regularly.
- Maintaining a good posture while walking, sitting, driving etc. for long hours.
- Maintaining a healthy weight to avoid pressure over the spine.
Herniated nucleus pulposus or herniated disc is a very painful condition and the person suffering from it experiences chronic discomfort. Hence, it is very essential to prevent the condition from occurring due to poor posture, obesity, occupational strain or substance abuse. It is very important to seek medical treatment at the earliest with the onset of mild symptoms so that it doesn’t progress further. Once progressed, the treatment and management protocol has to be followed without fail to get relief.