Lyme disease, caused by the bacterium Borrelia burgdorferi, is a tick-borne illness that affects various body systems, including the joints, heart, and nervous system. Sciatica is a collection of symptoms—pain radiating from the lower back down the leg—often due to irritation of the sciatic nerve. While mechanical compression, such as a herniated disc, is the most common cause of sciatica-like pain, inflammation from a systemic infection is another significant cause. Lyme disease can manifest with symptoms virtually identical to sciatica, confirming that the infection can directly cause this debilitating nerve pain.
How Lyme Disease Targets the Nervous System
When Borrelia burgdorferi spreads from the initial infection site, it can invade the nervous system, a condition known as Neuroborreliosis. This occurs in approximately 10 to 15 percent of untreated Lyme cases and causes a range of neurological symptoms. The bacteria trigger a significant inflammatory response as the immune system attempts to clear the infection from these sensitive tissues.
This inflammation can affect both the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves extending to the limbs). The presence of the spirochetes, combined with the body’s reaction, causes swelling and irritation of the delicate nerve structures. When this inflammatory process targets the peripheral nerves near the spinal column, the resulting irritation produces pain that mimics sciatica symptoms.
Lyme Radiculopathy: Symptoms Mimicking Sciatica
The specific neurological complication that produces sciatica-like pain is called radiculopathy—inflammation of a nerve root where it exits the spine. In the context of Lyme disease, this is termed Lyme radiculopathy. Symptoms feel similar to mechanical sciatica because the same nerve pathways are affected, resulting in sharp, electric, or shooting pain that travels down the leg.
Lyme radiculopathy often presents with distinguishing characteristics that help differentiate it from a mechanically pinched nerve. The pain is frequently reported to be disproportionately severe, especially at night, often disrupting sleep. This pain may also be migratory or involve the trunk area, which is atypical for standard mechanical sciatica.
Patients frequently experience sensory changes such as numbness, burning, or tingling in the affected limbs. While mechanical sciatica usually affects one side, Lyme radiculopathy can sometimes be bilateral, involving both legs or multiple nerve roots simultaneously. This inflammatory process, rather than physical compression, is the underlying source of the nerve irritation.
Diagnostic Steps for Nerve Pain Caused by Infection
Diagnosing Lyme radiculopathy requires a careful differential diagnosis to distinguish it from mechanical causes of sciatica. Professionals often start with imaging tests, such as an MRI or X-ray, to check for structural problems like a herniated disc or spinal stenosis. Mild or normal imaging results, despite severe pain, often raise suspicion of an infectious or inflammatory cause.
Once mechanical compression is ruled out, laboratory testing for Lyme disease becomes necessary. The standard approach involves a two-tiered serologic test, starting with an Enzyme-Linked Immunosorbent Assay (ELISA), followed by a Western Blot if the first test is positive or equivocal. These tests detect the presence of antibodies the body has produced against Borrelia burgdorferi.
For a definitive diagnosis of Neuroborreliosis, a lumbar puncture (spinal tap) may be performed. This procedure analyzes the cerebrospinal fluid (CSF) for signs of infection, such as an elevated white blood cell count (pleocytosis), and the presence of locally produced anti-Lyme antibodies. Proving the bacteria have invaded the central nervous system confirms Lyme as the source of the nerve pain.
Treatment When Lyme is the Underlying Cause
Treatment for sciatica-like pain caused by Lyme disease differs significantly from that of mechanical compression, as the primary goal is to eliminate the bacterial infection. Standard treatments for mechanical sciatica, such as physical therapy or anti-inflammatory drugs, only offer temporary symptom management without addressing the root cause. A confirmed diagnosis of Lyme radiculopathy requires antibiotic therapy to clear the Borrelia spirochetes from the nervous tissue.
In cases of nerve involvement, treatment typically involves a course of antibiotics. This may include oral medication like doxycycline or, for more severe presentations, intravenous (IV) ceftriaxone. The duration, often ranging from two to four weeks, is determined by the severity of the neurological symptoms.
Eradicating the bacteria allows the inflammation of the nerve roots to subside, leading to a resolution of the radicular pain. Recovery time varies based on how quickly the diagnosis was made and the extent of nerve damage that occurred before treatment began.