Bilateral Subdural Hematoma Caused by Cervical Traction

Abstract

Cervical traction therapy is commonly used for cervical spondylosis; however, complications, such as subdural hematomas can occur. Possible mechanisms include cerebrospinal fluid (CSF) leakage and bridging vein damage. A 51-year-old Japanese woman developed a persistent headache after 2 weeks of cervical traction therapy. Magnetic resonance imaging revealed bilateral subdural hematomas. Bed rest, oral analgesics, and daily infusion therapy failed to improve symptoms, but 2 epidural blood patches led to recovery. Although no direct CSF leakage was found, a spinal epidural lesion may have contributed. Cervical traction therapy may cause subdural hematomas via intracranial hypotension. Clinicians should consider this risk and conduct thorough diagnostic evaluations in affected patients.

Introduction

Cervical traction therapy for cervical spondylosis is a widely used non-invasive treatment aimed at relieving nerve root compression and neck pain caused by cervical degenerative disease. It reduces nerve root compression, improves blood flow, and alleviates pain. Given that the appropriate setting of traction force and treatment duration greatly influences therapeutic outcomes, a patient-tailored approach is essential. Potential side effects and limitations in efficacy must also be considered. Moreover, further research is needed to evaluate the long-term efficacy and safety.^1-4 Subdural hematoma resulting from traumatic hypopressure syndrome, although recognized as a possible complication, is not well understood, and its incidence is unclear. It is a previously unreported side effect of cervical traction therapy. In this study, we present a case of bilateral subdural hematomas following cervical traction therapy and explore its pathophysiology and treatment considerations.

Case Presentation

The patient was a 51-year-old Japanese woman who had previously suffered from stiff shoulders and numbness in her fingertips and had been diagnosed with cervical spondylosis. She had no relevant medical history and was not taking any anticoagulant medication. She underwent cervical traction therapy for 2 weeks to relieve her shoulder stiffness and neck pain (Figure 1). Therapy was performed with a traction force of approximately 15 kg, approximately 20% of her body weight. The first and second sessions lasted approximately 10 minutes and were conducted 2 to 3 times per week. The duration was gradually increased to 15 minutes from the third session and to 20 minutes from the fifth session. The physical therapists administering the treatments varied day to day, with 5 to 12 years of experience. The patient’s shoulder stiffness and fingertip numbness improved from the second session. However, from the fourth session onward, she began to experience temporary mild dizziness. The day after the fifth session, she developed a headache unlike any she had ever experienced. The persistent, cramping headache did not respond to analgesics. As the pain worsened with head elevation, magnetic resonance imaging (MRI) was performed, revealing bilateral subdural hematomas (Figure 2A-D). Cisternal scintigraphy and CT myelography showed no direct evidence of cerebrospinal fluid (CSF) leakage. However, previous studies have suggested spontaneous intracranial hypotension (SIH) as a cause of bilateral subdural hematomas. ⁵ In this case, SIH was suspected to have occurred secondary to cervical traction therapy, possibly damaging the bridging veins and resulting in subdural hematoma formation.

Figure 1.

Clinical course of symptoms and therapies.

Figure 2.

Longitudinal changes in MRI findings. (A-C): Initial evaluation of bilateral subdural hematomas. (A) T1-weighted image (T1); (B) T2-weighted axial image (T2a); (C) Fluid-attenuated inversion recovery image (FLAIR); (D) T2-weighted coronal image (T2c). (E-H): Follow-up MRI after initial treatment: (E), T1; (F), T2a; (G), FLAIR; (H), T2c. (I-L): Post-EBP MRI: (I), T1; (J), T2a; (K), FLAIR; (L), T2c.

Initial treatment included approximately 1 month of bed rest and oral analgesics (loxoprofen and acetaminophen), but the symptoms persisted, and follow-up MRI showed no significant improvement (Figure 2E-H). The patient also complained of tinnitus and diplopia. After 1 month of daily intravenous infusion therapy, the tinnitus and diplopia resolved, but the headache remained. Two months after the initial therapy, she underwent epidural blood patch (EBP) treatment. Within a few days, her headache significantly improved, and follow-up MRI confirmed resolution of the bilateral subdural hematomas (Figure 2I-L).

Discussion

Cervical traction therapy is widely employed for managing cervical spondylosis; however, its potential complications, including subdural hematomas, remain insufficiently understood. In this case, a 51-year-old woman developed bilateral subdural hematomas following 2 weeks of cervical traction therapy, suggesting a possible correlation between traction-induced intracranial hypotension and subsequent hematoma formation. Previous studies have described cases in which CSF leaks resulted in subdural hematomas as a result of low intracranial pressure. ⁶ Although no direct evidence of CSF leakage was found in this patient, a spinal epidural lesion may have contributed to intracranial hypotension, increasing the risk of venous damage, and hematoma development.

The mechanism underlying traction-induced subdural hematomas likely involves disruption of bridging veins resulting from altered intracranial dynamics. When CSF pressure decreases, the brain may descend slightly, placing tension on the bridging veins, which can rupture and result in hematomas. Similar findings have been reported in cases of SIH, where bridging vein laceration was identified as a contributing factor. ⁷ Additionally, cervical traction may exert excessive mechanical stress on the spinal dura, affecting CSF flow and pressure regulation, thereby increasing vulnerability to hematoma formation. Bridging veins are small vessels that return blood from the surface of the brain to the dural venous sinuses, traversing the subdural space between the brain and dura mater. In this case, pre-existing brain atrophy and venous fragility were unlikely, and the subacute clinical course argues against microdisplacement of the brain resulting from sudden traction. The presumed cause was an inappropriate traction angle (excessive forward flexion), which stretched the dura mater at the skull base and cervical spinal cord, increasing venous tension. Alternatively, excessive traction force (commonly > 12 kg) or a sudden increase in force may have placed undue stress on cervical soft tissues, the dura mater, and the venous system. This case highlights a clinically significant interaction between decreased intracranial pressure and bilateral chronic subdural hematomas. The rapid progression of hematoma formation alongside signs of CSF depletion suggests that reduced intracranial pressure may stretch bridging veins and increase their risk of rupture. This mechanism highlights the importance of recognizing decreased intracranial pressure as a potential trigger for the formation and recurrence of subdural hematomas. ⁸

Treatment strategies for subdural hematomas vary depending on severity and etiology. Conservative management may be appropriate for smaller hematomas and includes bed rest, hydration, and analgesics. In this case, the patient underwent daily infusion therapy for 1 month, which resulted in clinical and radiological improvement. Adequate hydration is known to play a critical role in restoring CSF volume and mitigating complications associated with intracranial hypotension. In cases where CSF leakage is confirmed, epidural blood patch (EBP) is an effective intervention to seal the dural defect and normalize intracranial pressure. Surgical drainage may be warranted in cases involving large hematomas or progressive neurological deterioration.

In the management of subdural hematomas secondary to SIH, addressing the underlying CSF leakage is essential. EBP is effective in sealing the leak and often leads to spontaneous hematoma resolution. In this case, conservative measures—including analgesics, bed rest, and continuous intravenous infusion—were initially selected because of concern for potential side effects; however, headache relief was only temporary. Based on the clinical course, earlier administration of EBP may have been more beneficial.^9,10 Furthermore, in patients with significant symptoms and large hematoma volumes, hematoma drainage under intracranial pressure monitoring should be considered when EBP alone proves insufficient. ¹¹

Given these associated risks, clinicians should exercise caution when prescribing cervical traction therapy, particularly in patients with potential risk factors for intracranial hypotension. Post-treatment monitoring is essential to detect early signs of complications such as persistent headache or neurological deficits. Although cervical traction remains a valuable therapeutic option, its potential adverse effects must be carefully weighed. In this case, SIH was diagnosed based on the clinical course; however, a definitive diagnosis could not be established because of the absence of intracranial pressure measurement. Future research should aim to establish standardized guidelines for identifying and managing patients at risk for traction-related complications to ensure safer therapeutic practices.

Conclusions

In conclusion, this case highlights the need for increased awareness of traction-induced subdural hematomas and intracranial hypotension.