What Is Brown-Séquard Syndrome? Symptoms, Causes, and Treatment Options
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is Brown-Séquard syndrome?
Brown-Séquard syndrome (BSS) is a rare, treatable condition caused by damage to one side of the spinal cord, causing weakness on the injured side and loss of pain and temperature sensation on the opposite side. [4] Penetrating trauma is the most common cause. [4] With surgery and rehabilitation the prognosis is usually good, though recovery can take up to two years. [4]
Key takeaways
BSS is caused by damage to one side of the spinal cord and is classified as an incomplete spinal cord injury. [4]
It produces a unique pattern: weakness or paralysis on the same side as the damage and loss of pain and temperature sensation on the opposite side. [4]
Trauma — gunshot wounds, stab wounds, motor vehicle accidents, and spinal fractures — is the most common cause. [4]
BSS is rare, accounting for an estimated 2% to 4% of the more than 18,000 new traumatic spinal cord injuries in the U.S. each year, affecting females and males equally. [4]
MRI is the most useful test to confirm the diagnosis; myelogram plus CT, blood tests, and spinal tap are used when needed. [4]
Treatment has two phases — initial care (surgery, medications, skin and bladder care) and rehabilitation — and the overall prognosis is usually good. [4]
What the research says
Recovery after Brown-Séquard syndrome looks similar to recovery after other incomplete spinal cord injuries. In a study of 15 age-matched pairs of people with neck-level (tetraparetic) incomplete injuries from nine European spinal cord injury rehabilitation centers, researchers compared motor score, walking function, daily-life activities, nerve conduction, and length of stay at 1 and 6 months. They found no difference in the time course of improvement between Brown-Séquard syndrome and central cord syndrome, despite the common assumption that Brown-Séquard syndrome has a better outcome (Wirz et al., Spinal Cord, 2010) [1].
Penetrating injuries are a documented but uncommon cause. A literature review that screened 338 PubMed results (258 of them case reports) found 16 reported cases of Brown-Séquard syndrome caused by an object retained in the spine — knives in 5, screwdrivers in 3, and glass in 3 — in people aged 11 to 72 (male-to-female ratio 11:5). Non-missile penetrating spine injuries are estimated to account for 0.8% of spinal cord injuries in Western countries (Abdulqader et al., Surg Neurol Int, 2022) [2].
What Is Brown-Séquard Syndrome (BSS)?
Brown-Séquard syndrome (BSS) is a rare neurological condition that happens when damage to your spinal cord causes muscle weakness or paralysis on one side of your body and a loss of sensation on the opposite side. The damage occurs on only one side of the spinal cord in a specific area. [4]
Your spinal cord is a cylindrical structure that runs through the center of your spine, from your brainstem to your low back. It is a delicate structure containing nerve bundles and cells that carry messages from your brain to the rest of your body and vice versa. It is one of the main parts of your nervous system.
Brown-Séquard syndrome is considered an incomplete spinal cord injury (SCI), meaning there is partial preservation of sensory function, motor function, or a combination of both below where the injury occurred. A complete SCI results in the loss of all sensory and voluntary motor functions below the level of the injury. [4]
BSS has several possible causes, but the most common is trauma — typically penetrating trauma such as a gunshot or stab wound. Inflammation or pinching of the spinal cord can also occasionally cause BSS. [4]
BSS is named after scientist Charles-Édouard Brown-Séquard, who first described it in 1849. [4]
How Is BSS Different From Central Cord Syndrome?
Central cord syndrome (CCS) and Brown-Séquard syndrome (BSS) are both incomplete spinal cord injuries, but they are distinct conditions:
Feature | Brown-Séquard syndrome (BSS) | Central cord syndrome (CCS) |
Injury location | One side of the spinal cord, anywhere along the spine | The center of the spinal cord, usually in the neck |
Main effect | Weakness or paralysis on one side of the body; loss of sensation on the other side, below the injury | Weakness in the arms that is worse than in the legs |
Injury type | Incomplete spinal cord injury | Incomplete traumatic spinal cord injury |
Who Does Brown-Séquard Syndrome Affect?
BSS can affect anyone, though it is a rare condition. It affects females and males in equal numbers. [4]
How Common Is Brown-Séquard Syndrome?
BSS is rare. Approximately 18,000 new cases of traumatic spinal cord injuries happen each year in the United States, and BSS is estimated to result from 2% to 4% of these cases. [4]
Brown-Séquard Syndrome Symptoms
Symptoms of BSS usually appear after a spinal cord injury that damages only one side of the spinal cord in a specific area, anywhere along the spine.
The first symptoms of BSS are usually:
For example, if someone had BSS from an injury affecting the right side of their spinal cord in the middle back, they would have a loss of muscle movement on the right side of the body from the middle of the back and down — affecting the right hip, leg, and foot. They would have a loss of pain and temperature sensation (but still have muscle control) on the left side of the body from the middle back and down. The head, neck, shoulders, and arms would be unaffected and function normally.
BSS can also cause the following symptoms:
Loss of bladder and bowel control (urinary and fecal incontinence).
Weakness and muscle atrophy in the affected area.
The symptoms of BSS can vary from mild to severe. They generally improve with proper treatment. [4]
Is Brown-Séquard Syndrome Painful?
If the cause of BSS is a traumatic event, such as a gunshot wound or vehicle collision, that event will cause pain. But the syndrome itself (the spinal cord injury) may not cause pain.
Some people with BSS may experience abnormal sensations (dysesthesia), such as a painful burning, prickling, or aching feeling, due to the spinal cord injury. [4]
What Causes Brown-Séquard Syndrome?
The most common causes of BSS are traumatic injuries affecting the spinal cord. If you experience any of these injuries, it is important to get to the nearest hospital as soon as possible and receive immediate medical care.
Traumatic cause | Details |
Gunshot wounds | Penetrating trauma, the most typical cause |
Stab wounds | Penetrating trauma damaging one side of the cord |
Motor vehicle accidents | Major blunt force to the spine |
Blunt trauma | Non-penetrating impact injuries |
Spinal fractures | Often from a fall |
There are several other less common causes of BSS due to non-traumatic conditions:
Non-traumatic cause | Details |
Cervical (neck) spondylosis | Degenerative changes in the neck spine |
Decompression sickness | Pressure-related spinal damage |
Herniated disk | Disk material pressing on the cord |
Meningitis | Inflammation of the membranes around the cord |
Multiple sclerosis (MS) | Autoimmune damage to nerve tissue |
Radiation exposure | Radiation-related spinal cord damage |
Spinal ischemia | Obstruction of a blood vessel supplying the cord |
Spinal tumors | Growths compressing the cord |
Transverse myelitis | Inflammation across the spinal cord |
Tuberculosis | Infectious damage to the spine |
How Is Brown-Séquard Syndrome Diagnosed?
If a provider suspects BSS, they will perform a thorough physical exam and a neurological exam consisting of detailed motor and sensory evaluation. They will also ask detailed questions about medical, neurological, and trauma history, then order tests such as an MRI to confirm the diagnosis or rule out other possible causes. [4]
Test | Purpose |
Magnetic resonance imaging (MRI) | The most useful imaging test for BSS; painless; identifies structural damage in the spine and helps evaluate non-traumatic causes |
Myelogram + CT scan of the spine | Used if MRI is not possible; a myelogram examines the relationship between the vertebrae, disks, spinal cord, nerves, and nerve roots, followed by a CT scan that uses X-rays to reveal nerve tissue damage on one side of the cord |
Blood tests | Used when the cause is unclear, to check for an infection that might be causing the condition |
Lumbar puncture (spinal tap) | Performed if MS, transverse myelitis, or tuberculosis is suspected; a sample of cerebrospinal fluid (CSF) — the clear liquid surrounding the spine and brain — is analyzed |
How Is Brown-Séquard Syndrome Treated?
Treatment for BSS depends on the underlying cause of the spinal cord damage. In general, the treatment goals include preserving or improving motor and sensory function, preventing secondary injuries, and minimizing complications. [4] People with BSS from a penetrating injury will need treatment for bleeding and direct tissue damage, and those with other injuries from the trauma need additional treatment for those injuries.
Treatment has two general phases: initial treatment and rehabilitation. [4]
Initial Treatment
Initial therapy | How it helps |
Surgery | Non-traumatic causes usually involve mechanical compression or herniation of the spinal cord requiring surgery to relieve the compression |
Blood clot prevention | Spinal cord injury patients have the highest rate of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism; anticoagulants such as heparin or warfarin help prevent clots |
Skin care for pressure injuries | The care team rotates and repositions the body at least every two hours, keeps skin clean and dry, and moisturizes dry skin to prevent bedsores |
Gastrostomy tube (G-tube) | A tube inserted through the belly to reduce abdominal distension from paralytic ileus — when the intestinal muscle contractions that move food are temporarily paralyzed, common in spinal cord injuries |
Breathing support | A ventilator helps or breathes for the patient if the injury causes breathing problems |
Neurogenic bladder management | A urinary catheter and other urological treatments if bladder control is lost |
Autonomic dysreflexia treatment | Careful management of marked blood pressure fluctuations with blood pressure and heart medications |
Temperature-regulating blankets | People with BSS often cannot regulate their body temperature |
Rehabilitation
After initial care, rehabilitation through physical and occupational therapy should begin as soon as possible to improve or regain motor function. [4]
Physical therapy goals include maintaining strength in neurologically intact muscles, maintaining range of motion in joints, preventing skin breakdown through proper positioning and weight shifting, and improving mobility. [4] Physical therapy involves therapies and exercises to ease pain and help with function and movement, and the therapist may provide devices such as braces, hand splints, limb supports, or a wheelchair.
Occupational therapy involves therapies and exercises that help people regain independence in all areas of life after a physical or neurological issue. During occupational therapy for BSS, patients learn new techniques — with or without adaptive equipment — for everyday tasks such as hygiene and grooming, eating, and dressing. [4]
What Is the Outlook With Brown-Séquard Syndrome?
The prognosis depends on several factors, including the cause of the spinal cord damage and how much it is damaged. Overall, the prognosis of BSS is usually good. People with BSS have a fair chance of recovering some of their function, including walking. Recovery is a slow process, however. It becomes slower three to six months after the onset of the syndrome, and it can take up to two years for ongoing neurological recovery. [4]
Possible Complications
If left untreated, BSS may result in the following complications:
Complication | Details |
Abdominal distension | Swelling of the abdomen, often linked to paralytic ileus |
Depression | Emotional impact of a serious neurological injury |
Low blood pressure (hypotension) | Abnormally low blood pressure |
Pulmonary embolism | A blood clot in the lung |
Infections | Most commonly in the lungs and urinary tract |
Permanent paralysis | Lasting loss of motor function |
Can You Prevent Brown-Séquard Syndrome?
The only way to prevent BSS is to practice standard safety, such as driving and traffic safety, to try to prevent injuring the spinal cord. [4]
Living With Brown-Séquard Syndrome
When to seek care: If you experience sudden muscle weakness or paralysis and/or loss of sensation on one side of your body, get to the nearest emergency room as soon as possible.
After diagnosis: See the healthcare team regularly to make sure the spinal cord injury is healing properly. Attend all physical and occupational therapy appointments to ensure the best and quickest recovery possible.
A reassuring note: Brown-Séquard syndrome can be scary to experience. The good news is that many people with this condition regain or have improved motor and sensory function after several months of recovery.
Conclusion
Brown-Séquard syndrome is a rare but treatable neurological condition with a distinctive signature: damage to one side of the spinal cord weakens or paralyzes the same side of the body while numbing the opposite side to pain and temperature. Most cases begin with trauma — a gunshot, a stab wound, a car crash, or a fall — and the condition accounts for an estimated 2% to 4% of traumatic spinal cord injuries each year. Because it is an incomplete spinal cord injury, much function is preserved, and the treatment path is well established: surgery when needed, clot and pressure injury prevention, bladder and temperature support, followed by dedicated physical and occupational therapy.
The overall prognosis is usually good. Many people regain or improve motor and sensory function, including walking, over months — with full neurological recovery sometimes taking up to two years. For anyone creating health education materials, visual explanations of spinal cord injuries and rehabilitation pathways make a daunting diagnosis far easier to understand. Explore Rinnit's infographic templates to build educational visuals for topics like this one.
Frequently Asked Questions
What is Brown-Séquard syndrome (BSS)?
BSS is a rare neurological condition caused by damage to one side of the spinal cord in a specific area. It causes muscle weakness or paralysis on one side of the body and loss of sensation on the opposite side.
Is Brown-Séquard syndrome a complete or incomplete spinal cord injury?
Brown-Séquard syndrome is an incomplete spinal cord injury, meaning there is partial preservation of sensory function, motor function, or both below the level of the injury. A complete spinal cord injury causes total loss of all sensory and voluntary motor functions below the injury.
What does the spinal cord do?
The spinal cord is a cylindrical structure running through the center of the spine, from the brainstem to the low back. It contains nerve bundles and cells that carry messages between the brain and the rest of the body, and it is one of the main parts of the nervous system.
What are the first symptoms of BSS?
The first symptoms are usually loss of voluntary muscle movement (weakness or paralysis) on the same side of the body as the spinal cord damage, below the injury level, and loss of pain and temperature sensation on the opposite side, below the injury.
Why does weakness occur on one side and numbness on the other?
The damage occurs on only one side of the spinal cord. The pathways affected produce motor loss on the same side as the damage and sensory loss (pain and temperature) on the opposite side, below the injury level.
What does an example case look like?
If the right side of the spinal cord in the middle back is injured, the person loses muscle movement on the right side from the middle back down (hip, leg, foot) and loses pain and temperature sensation — but keeps muscle control — on the left side from the middle back down. The head, neck, shoulders, and arms are unaffected.
Does BSS affect bladder and bowel control?
Yes. BSS can cause loss of bladder and bowel control, known as urinary and fecal incontinence.
Does BSS cause muscle wasting?
Yes. Weakness and muscle atrophy can occur in the affected area.
How severe is BSS?
Symptoms can vary from mild to severe, and they generally improve with proper treatment.
Is BSS painful?
The traumatic event that causes BSS causes pain, but the syndrome itself may not. Some people experience dysesthesia — abnormal sensations such as painful burning, prickling, or aching — due to the spinal cord injury.
What is the most common cause of BSS?
Traumatic injuries to the spinal cord are the most common cause, typically penetrating trauma such as gunshot or stab wounds.
What traumatic injuries can cause BSS?
Gunshot wounds, stab wounds, motor vehicle accidents, blunt trauma, and spinal fractures from accidents such as falls.
Can non-traumatic conditions cause BSS?
Yes. Less common causes include cervical spondylosis, decompression sickness, herniated disk, meningitis, multiple sclerosis, radiation exposure, spinal ischemia (blocked blood vessel), spinal tumors, transverse myelitis, and tuberculosis.
Who gets Brown-Séquard syndrome?
Anyone can be affected, though it is rare. Females and males are affected in equal numbers.
How common is BSS in the United States?
More than 18,000 new traumatic spinal cord injuries occur each year in the U.S., and BSS results from an estimated 2% to 4% of these cases.
How is BSS diagnosed?
The provider performs a thorough physical exam, a neurological exam with detailed motor and sensory evaluation, and a detailed history of medical, neurological, and trauma events. Imaging such as MRI confirms the diagnosis or rules out other causes.
Is MRI the best test for BSS?
MRI is the most useful imaging test for BSS. It is painless, identifies structural damage in the spine, and helps evaluate non-traumatic causes.
What if someone cannot have an MRI?
The provider will likely order a myelogram immediately followed by a CT scan of the spine. These tests can reveal nerve tissue damage on one side of the spinal cord.
When is a lumbar puncture needed?
If the provider suspects multiple sclerosis, transverse myelitis, or tuberculosis, a lumbar puncture (spinal tap) collects a sample of cerebrospinal fluid — the clear liquid surrounding the spine and brain — for analysis.
What are the goals of BSS treatment?
Treatment aims to preserve or improve motor and sensory function, prevent secondary injuries, and minimize complications. Treatment depends on the underlying cause of the spinal cord damage.
Is surgery used for BSS?
Yes. Non-traumatic causes usually involve mechanical compression or herniation of the spinal cord, which requires surgery to relieve the compression.
Why are blood thinners given?
People with spinal cord injuries have the highest rate of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism. Anticoagulants such as heparin or warfarin help prevent blood clots.
How are bedsores prevented?
The healthcare team rotates and repositions the body at least every two hours, keeps the skin clean and dry, and uses moisturizers to treat dry skin.
What is paralytic ileus and how is it managed?
Paralytic ileus occurs when the muscle contractions that move food through the intestines are temporarily paralyzed, common in spinal cord injuries. It can cause abdominal distension, and a G-tube (gastrostomy tube) inserted through the belly may be placed to reduce this risk.
Can BSS affect breathing?
Yes. If the spinal cord injury causes breathing problems, the patient may need a ventilator — a machine that helps breathe or breathes for the patient.
What happens if bladder control is lost?
A urinary catheter and other urological treatments may be required to manage the neurogenic bladder.
What is autonomic dysreflexia in BSS?
People with spinal cord damage may have marked fluctuations in blood pressure and other symptoms, which need careful management with blood pressure and heart medications.
Why are temperature-regulating blankets used?
People with BSS often cannot regulate their body temperature, so the healthcare team may provide temperature-regulating blankets.
What does rehabilitation involve?
Physical and occupational therapy should begin as soon as possible after initial care. Physical therapy maintains strength in intact muscles, preserves joint range of motion, prevents skin breakdown, and improves mobility. Occupational therapy teaches techniques for daily tasks like hygiene, grooming, eating, and dressing.
What devices might physical therapy provide?
A physical therapist may provide braces, hand splints, limb supports, or a wheelchair to help with daily activities.
What is the prognosis for BSS?
Overall, the prognosis is usually good. People with BSS have a fair chance of recovering some of their function, including walking, though recovery is slow.
How long does recovery take?
Recovery becomes slower three to six months after onset, and it can take up to two years for ongoing neurological recovery.
What complications can occur without treatment?
Untreated BSS may lead to abdominal distension, depression, low blood pressure, pulmonary embolism, infections (most commonly in the lungs and urinary tract), and permanent paralysis.
Can BSS be prevented?
The only prevention is practicing standard safety, such as driving and traffic safety, to try to prevent spinal cord injury.
When should someone go to the emergency room?
Sudden muscle weakness or paralysis and/or loss of sensation on one side of the body require an immediate visit to the nearest emergency room.
Is Brown-Séquard syndrome the same as central cord syndrome?
No. Central cord syndrome is an incomplete injury to the center of the spinal cord, usually in the neck, causing arm weakness worse than leg weakness. BSS results from an injury anywhere along the spine, causing weakness on one side and sensation loss on the other.
Can people with BSS walk again?
Many people with BSS regain or improve motor and sensory function after several months of recovery, including the ability to walk.
Related Reading
Spinal Cord Injury Guide: Symptoms, Causes, Diagnosis, and Treatment
What Is Urinary Incontinence? Types, Causes, and Treatments Explained
What Is Multiple Sclerosis? A Plain-Language Guide to Symptoms, Types, and How It's Treated
Spinal Tumor: Symptoms, Causes, Diagnosis, and Treatment Explained
Deep Vein Thrombosis (DVT): Symptoms, Causes, Diagnosis & Treatment — Complete Guide
Pulmonary Embolism Guide: Symptoms, Causes, Diagnosis, and Treatment
Understanding Meningitis: Symptoms, Causes, and Emergency Care
What Is Autonomic Dysreflexia? Warning Signs, Triggers, and What to Do
Spinal Fractures: Symptoms, Causes, Diagnosis, Treatment and Outlook — What You Need to Know
References
Wirz M, Zörner B, Rupp R, et al. Outcome after incomplete spinal cord injury: central cord versus Brown-Sequard syndrome. Spinal Cord. 2010;48(5):407-414. PMID: 19901956. https://doi.org/10.1038/sc.2009.149
Abdulqader MN, Ismail M, Al-Khafaji AO, et al. Brown-Sequard syndrome associated with a spinal cord injury caused by a retained screwdriver: A case report and literature review. Surg Neurol Int. 2022;13:520. PMID: 36447879. https://doi.org/10.25259/SNI_957_2022
Franges EZ. Solving the puzzle of Brown-Séquard syndrome. Nursing. 2021;51(4):62-66. PMID: 33759868. https://doi.org/10.1097/01.NURSE.0000733960.67995.78
Cleveland Clinic. Brown-Séquard Syndrome: Causes, Symptoms & Treatment. Cleveland Clinic. Last updated April 11, 2022. https://my.clevelandclinic.org/health/diseases/22749-brown-sequard-syndrome-bss
Medical disclaimer
This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider with any questions about a medical condition. Sudden muscle weakness, paralysis, or loss of sensation on one side of the body is a medical emergency — seek immediate care.
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