Spinal Hematoma: Signs, Risks, and Diagnostic Insights

A spinal hematoma is a collection of blood that forms inside the spinal canal and compresses the spinal cord or the nerves branching from it. The hallmark presentation is sudden, severe back or neck pain followed rapidly by neurological deficits such as weakness, numbness, or paralysis in the limbs. The condition is rare, with spontaneous cases estimated at roughly one per million people per year, but it demands fast recognition because delays of even hours can mean the difference between full recovery and permanent disability.¹

What It Looks Like When It Happens

The classic scenario unfolds quickly. A person develops abrupt, intense pain in the back or neck that does not follow the pattern of a pulled muscle or a slipped disc. Within minutes to hours, neurological symptoms appear: tingling, heaviness, or outright inability to move the legs or arms depending on where the bleeding occurs. One case report describes a 76-year-old man who arrived at the hospital with sudden chest and back pain alongside complete paralysis of both legs.² That rapid progression from pain to paralysis is the red flag clinicians look for.

Bladder and bowel dysfunction can accompany the motor loss. Some people lose sensation below a certain level of the trunk. The speed of symptom progression varies: some patients deteriorate over minutes, others over a day or two. A slower onset does not make the situation less urgent, it simply reflects a slower rate of bleeding or a hematoma that initially forms without fully compressing the cord.

Where the Bleeding Comes From

The spinal canal contains arteries, veins, and a network of small blood vessels called the epidural venous plexus. Most researchers believe the venous plexus is the primary culprit in spontaneous spinal epidural hematomas because those veins lack valves, making them vulnerable to pressure swings in the chest and abdomen. The fact that most spontaneous cases form behind (dorsal to) the spinal cord supports the theory that the posterior venous plexus is the main source.³ Some investigators, however, have argued that arterial bleeding is sometimes responsible, and this may explain why certain hematomas expand rapidly enough to cause dramatic cord compression.

Risk Factors That Make Spinal Hematoma More Likely

Blood-thinning medications are the single most discussed risk factor. Around a fifth of spinal hematomas are linked to some form of clotting disorder or anticoagulant use.⁴ A systematic review of spontaneous spinal hematomas in patients on blood thinners found that nearly three-quarters of the cases involved anticoagulants such as warfarin or the newer direct oral anticoagulants, with the remainder linked to antiplatelet drugs.⁵ Other case series have put the proportion of anticoagulant-associated cases even higher, ranging from a quarter to as many as 70 percent of spontaneous epidural hematomas.⁶

Beyond anticoagulants, a range of conditions and exposures raise the risk:

• Vascular malformations: Abnormal tangles of blood vessels within or around the spinal cord can rupture with minimal provocation. Arteriovenous malformations are the most common cause of non-traumatic bleeding inside the spinal cord itself.⁷
• Bleeding disorders: Hemophilia, leukemia, and other conditions that impair clotting increase vulnerability.
• Minor trauma or exertion: Coughing, straining, or even mild spinal manipulation has been associated with epidural hematoma formation, especially in people with underlying risk factors.
• Spinal procedures: Epidural injections, spinal anesthesia, facet joint blocks, and acupuncture near the spine are recognized triggers in rare cases.⁸
• Pregnancy: Physiological changes in blood flow and clotting during pregnancy can contribute.

That said, a meaningful proportion of cases are truly spontaneous, with no identifiable trigger at all. Those are classified as idiopathic.

Spinal Hematoma After Epidural Anesthesia

One scenario that draws particular anxiety is the risk of a spinal hematoma following epidural analgesia, such as the kind used during labor or after surgery. A large U.S. study examining over 3.7 million epidural procedures found the risk varies dramatically by patient population. In obstetric patients, the rate of spinal hematoma was about 0.6 per 100,000 epidural catheter placements. In non-obstetric patients, the rate jumped to roughly 18.5 per 100,000, a 30-fold difference.⁹ Predictors of hematoma in that study included vascular surgery, teaching-hospital status, and the patient’s overall burden of other medical conditions. The takeaway is that while the absolute risk is low, it is not zero, and it rises substantially in older, sicker patients undergoing major surgery.

Hematomas after spinal procedures do not always appear at the puncture site. One reported case involved a large epidural hematoma that formed far from where the needle entered, caused by a previously undiagnosed vascular malformation that ruptured in connection with the procedure.¹⁰ Clinicians watching for post-procedure complications need to think beyond the immediate needle-entry level.

Chiropractic Manipulation and Other Mechanical Triggers

Spinal epidural hematoma after chiropractic manipulation is rare but documented. A literature review identified seven reported cases, most involving cervical manipulation, and one patient had been on anticoagulant therapy at the time.¹¹ In at least one case, the manipulation appeared to rupture a previously undiagnosed cervical arteriovenous malformation, and the case report stressed that patients with known vascular malformations should be cautioned against spinal manipulation even when it is performed correctly.¹² The difficulty, of course, is that many people carrying small vascular malformations do not know it until something goes wrong.

Subtypes of Spinal Hematoma

Not all spinal hematomas are the same. The location of the blood collection relative to the spinal cord membranes determines the subtype and influences both the clinical picture and the treatment approach.

Epidural Hematomas

Epidural hematomas sit between the vertebral bone and the outermost membrane (dura) surrounding the spinal cord. These are the most commonly discussed type and tend to form dorsal (behind) the cord. They account for most spontaneous and procedure-related spinal hematomas.

Subdural Hematomas

Spinal subdural hematomas form beneath the dura but outside the cord itself. In one case series, subdural hematomas were more common in the thoracic spine and tended to sit in front of the cord, whereas epidural hematomas were always behind it.¹³ This positional difference matters on imaging and can influence how a surgeon plans the approach.

Intramedullary Hemorrhage

Bleeding directly within the spinal cord tissue, called hematomyelia, is the rarest and often the most devastating subtype. The most common non-traumatic cause is a vascular malformation inside the cord, particularly intramedullary cavernomas. Other causes include anticoagulant therapy, spinal cord tumors, and, in unusual cases, a delayed effect of spinal radiation.¹⁴ Hematomyelia can present acutely or in a stepwise fashion, and it often produces a pattern of neurological deficits that reflects damage to the center of the cord rather than compression from outside it.

How Spinal Hematomas Are Diagnosed

MRI is the gold standard. It can show the hematoma’s location, size, and age, and it can reveal underlying causes such as vascular malformations or tumors. The appearance of the blood on MRI changes as the hematoma ages. A very fresh (hyperacute) hematoma looks similar to the spinal cord itself on one type of MRI sequence and bright on another, while an older hematoma may appear bright on both sequences or, in the chronic phase, dark on both.¹⁵ Understanding these signal patterns helps radiologists estimate when the bleeding occurred, which can influence treatment decisions.

The bigger diagnostic challenge is not the scan itself but getting to the scanner in time. In the emergency department, a spinal hematoma can masquerade as a heart attack, a stroke, or an aortic dissection, particularly when the initial symptom is chest or back pain. One case report described a 43-year-old man who was initially investigated for a cardiac event, a posterior stroke, and an arterial dissection before the correct diagnosis was made.¹⁶ These diagnostic detours burn precious hours.

Surgery Versus Conservative Treatment

Emergency surgical decompression, typically a laminectomy to remove the bone overlying the hematoma and evacuate the blood, is the standard treatment when neurological deficits are worsening. The goal is to relieve pressure on the cord before permanent damage sets in. Conservative management, meaning close monitoring without surgery, is an option when symptoms are mild and stable or when neurological function is already recovering on its own.¹⁷ One comparative study found that conservative management was feasible in patients who had no motor deficit at all or who were already showing early recovery of function.¹⁸

For patients on anticoagulants who need emergency surgery, reversing the blood thinning comes first. Prothrombin complex concentrates have been used to rapidly bring clotting function back toward normal. In one series of anticoagulated patients needing urgent spinal decompression, these concentrates brought the international normalized ratio (a measure of how thinned the blood is) down from an average of about 2.3 to roughly 1.1, allowing surgery to proceed within hours.¹⁹ In patients taking newer direct oral anticoagulants, prothrombin complex concentrates were also administered in most cases requiring surgery.²⁰

Why Timing Changes Everything

The evidence on surgical timing is about as clear as it gets in this field. A large series of epidural hematoma cases found that patients who went to surgery within 12 hours of symptom onset had better neurological outcomes than those with identical pre-operative deficits whose surgery was delayed beyond 12 hours. The study also showed that pre-operative neurological status mattered independently: roughly 83 percent of patients who still had some leg movement before surgery recovered completely, compared with only 25 percent of those who had complete paralysis.²¹

There is some encouraging nuance, though. A more recent case series found that significant neurological recovery after surgical decompression could still be achieved even when patients had substantial pre-operative deficits or when surgery was somewhat delayed, suggesting the 12-hour window is not an absolute cutoff beyond which all hope is lost.²² Still, faster is reliably better.

Children and Spinal Hematomas

Spinal hematomas in children are exceptionally rare. Since the condition was first described, only a few dozen pediatric cases have appeared in the literature.¹ The presentation can be atypical: younger children may not articulate neck or back pain clearly and instead become irritable, refuse to move, or simply cry. In pediatric cases, the hematoma is often spontaneous, sometimes connected to an underlying clotting abnormality or athletic trauma.²³

A systematic review of pediatric cases highlighted that screening for bleeding disorders is warranted and that imaging follow-up after treatment is essential because vascular malformations are a common underlying cause that may need separate treatment. In one reported case, a 7-year-old girl developed an epidural hematoma after only a minor cervical sprain, and surgical evacuation revealed an arteriovenous malformation. Another child, a 4-year-old boy with neck pain and no neurological deficit, was managed conservatively, and follow-up MRI at three months showed complete resolution.²⁴ Most children do well, but some do not recover fully, making vigilant neurological monitoring important.

The Medico-Legal Landscape

Because delayed diagnosis is the main driver of poor outcomes, spinal hematoma generates a disproportionate amount of litigation relative to how rare it is. A retrospective analysis of 101 U.S. malpractice cases involving epidural hematomas found that failure to diagnose was the most common allegation, cited in about 63 percent of suits. Spine surgery, trauma, and epidural injection or catheter placement were the leading procedural contexts. Neurosurgeons and anesthesiologists were the most commonly named defendants. Most cases resulted in a verdict favoring the defense, but when plaintiffs won, the average payout exceeded $3.6 million, and settlements averaged about $2.4 million.²⁵

An earlier, smaller analysis of lawsuits specifically focused on the timing question found that surgical delays beyond 48 hours were significantly associated with an unfavorable verdict for the physician.²⁶ In French medicolegal data examining postoperative epidural hematomas after spine surgery, the occurrence of the hematoma itself was usually considered a no-fault medical complication, but one surgeon was found liable specifically for taking 11 days to perform a surgical revision. In two additional cases, nurses were questioned for failing to alert the surgeon when symptoms first appeared.²⁷ The consistent thread across jurisdictions is that the hematoma forming is often treated as an inherent risk, but failing to act on it quickly is where liability begins.