An Overview of Back Pain and its Myriad Manifestations
Brian Hainline, M.D.
Low back pain is a very common and ubiquitous reason for patients to visit their primary care physician. When assessing patients for low back pain, it is important to differentiate between nociceptive and neuropathic pain.
Nociceptive pain is caused by the activation of nociceptors, a type of pain receptor that responds to chemical, mechanical or thermal stimuli. Nociceptors protect the body from a potential injury. For example, if you place your hand in a flame, you will immediately withdraw your hand in pain because of the activation of thermal nociceptors. In this case, the pain serves as a protective response to potential tissue damage.
Neuropathic pain is generated from within the nervous system and is the result of a lesion or dysfunction of the nervous system. Because of this, neuropathic pain does not serve to protect from pain against a potential tissue threat or injury. Neuropathic pain is transformed pain and is much more complex than nociceptive pain. Patients with neuropathic pain suffer in a multi-dimensional manner: physically, emotionally, mentally, spiritually, and socially.
When treating patients with low back pain, it is important to try to understand the source of the pain. For common low back conditions, one can usually identify if the pain is generated from the muscles, soft tissues, a herniated disc, the spinal joints, or from spinal canal encroachment. If one can identify the source, then it is highly likely that the pain is nociceptive in origin. Identifying the source of the pain allows for targeted treatment.
When back pain does not have a clear-cut target, it is most often an expression of transformed or neuropathic pain. In this case, pain becomes more constant, without clear precipitating or relieving features. Patients with neuropathic pain often describe a burning, deep aching pain that is essentially constant. If it is treated as nociceptive pain, treatment will usually be unsuccessful. Neuropathic pain is complex in nature and as such, requires a multi-disciplinary treatment approach.
It is simplistic to view low back pain as a result of a herniated disc. Lumbar disc degenerative changes and herniations are commonplace and do not necessarily result in pain. Low back pain is most often a result of a weakness of the deep rotator muscles of the back. An imbalance in these muscles can also exacerbate a tendency to develop pain from other structural causes. Therefore, if treatment simply addresses immediate pain control but does not address the underlying muscle imbalance, most likely there will be a recurrence of symptoms.
When a patient has low back pain, it is important to determine if there is a danger of permanent medical or neurological injury. If so, then the patient requires an immediate referral to a neurologist. The Division of Neurology and Integrative Pain Medicine at ProHEALTH is an appropriate referral source for patients who are in neurological or biomechanical danger as a result of their back condition.
If the patient is not in imminent danger, treatment can be started by the primary care physician. The cornerstone of initial treatment for uncomplicated low back pain is medical management coupled with physical therapy or chiropractic care. Medications may include nonsteroidal anti-inflammatory drugs (such as advil), corticosteroids (such as prednisone), muscle relaxers and opioid medications – the choice of medication depending on pain severity and type of pain. Uncomplicated back pain should resolve in 2 weeks.