Manipulation is defined by the International Federation of Manual Medicine as “the use of hands in the patient management process using instructions and maneuvers to maintain maximal, painless movement of the musculoskeletal system and postural balance”.¹ Spinal manipulation therapy (SMT) is widely used to treat low back pain and neck pain; its efficacy has been demonstrated in numerous randomized controlled trials.^2,3 Typical SMTs include mobilization and thrust. Mobilizations make use of low velocity, small-, or large-amplitude passive movement techniques within the patient’s range of motion and control, whereas thrust uses high-velocity impulses applied to a synovial joint over short amplitude at or near the end of the passive or physiological range of motion.³ SMT can sometimes be associated with complications, including stroke, myelopathy, radiculopathy, vertebral artery dissection, or even death. The complications are usually mild, but they can also lead to severe and permanent disability occasionally.^4-7 In Korea, recently, the number of people undergoing manual therapy for musculoskeletal disorders has increased, as have the reports of post-manual therapy side effects.⁸ Due to the current increase in the elderly population, the demand for treating musculoskeletal disorders is on the rise. However, a dangerous trend of discriminatory prescription of SMT without awareness of clear indications and contraindications and without monitoring by doctors, particularly musculoskeletal specialists, is observed. If this trend continues, the prevalence of complications is bound to increase. Therefore, this review aimed to report the myelopathy that occurred in our patient after SMT, raise awareness of this issue, which has been reported worldwide, alarm the doctors about the current practice of indiscri-minate prescription of manual therapy, and consider the risk of complications arising from it.

A 52-year-old man with a height of 173 cm and a weight of 70 kg presented to our emergency department with rapidly progressive quadriparesis. He had no underlying disease other than multiple cervical herniated intervertebral discs at C4/5, C5/6, and C6/7 (Fig. 1-A and 1-B). One day before he experienced the symptoms of quadriparesis, he had undergone manipulation therapy with thrusting at a massage shop from an unlicensed therapist without a doctor’s prescription to obtain relief from chronic neck pain. Before the therapy, his only symptom was pain without any motor weakness. After the manipulation therapy, however, he experienced an abrupt onset of bilateral weakness in all four extremities, leading to an inability to walk and severe numbness in both hands. Neurological examination revealed areflexia in the elbows, abdomen, and knees, along with hypoesthesia below the C5 dermatome, particularly in the C8-T1 dermatome. He also experienced weakness in all four limbs, with the upper limbs being more severely affected than the lower limbs. The manual muscle test (MMT) revealed a strength grade of 2 of 5 and 3 of 5 for the bilateral upper and lower extremities, respectively. He also complained of progressive difficulty in voiding and defecating.

Figure 1. Cervical spine magnetic resonance imaging (MRI) performed 3 months before the onset of symptoms. Sagittal and axial MRI showed multilevel herniated intervertebral discs from C4 to C7 and severe right central disc extrusion of C4/5 (A and B). After symptom onset, they indicate compressive myleopathy at C4/5 (C and D).

Compared to the cervical magnetic resonance imaging (MRI) performed three months ago, the current MRI scan confirmed spinal cord compression and surrounding edema due to the progression of C4/5 central disc herniation (Fig. 1-C and 1-D). An emergency anterior cervical decompression fusion at the level of C4/5 was performed (Fig. 2).

Figure 2. Cervical spine MRI and X-ray performed after surgery. C-spine lateral view (A) and anterioposterior view (B). Sagittal MRI and axial MRI of the same patient at the C4/5 level obtained indicated that the cord compression at C4/5 had resolved (C and D).

Immediately after the surgery, MMT improved to 3 of 5 and 4 of 5 for the bilateral upper and lower extremities, respectively. A nerve conduction study, median somatosensory evoked potentials (SEP), and needle electromyo-graphy (EMG) were performed one week after surgery. The examination indicated normal findings; however, motor evoked potentials (MEP) and tibial SEP were not performed (Table 1∼3). The patient was eager to resume walking and wanted to return to work. Three days after the surgery, he was initiated on comprehensive rehabilitation therapy to restore muscle strength and balance through sequential performance of hip extensor strengthening, stepping, and treadmill walking exercises supervised by a well-trained physical therapist to improve endurance. Additionally, the patient was trained to improve his independence in activities of daily living, including using chopsticks and having a bath. After rehabilitation therapy for three weeks, MMT improved to 4 of 5 for the bilateral upper and lower extremities. His Functional Independence Measure score improved to 108 of 126, and he achieved independence in activities of daily living.

Table 1 . Results of Nerve Conduction Studies.

Nerve	DSL (ms)	S Amp (μV)	DML (ms)	M Amp (μV)	NCV (m/s)
Median R	2.2	35	2.7	9.9	67
Median L	2.4	31	3.2	11	72
Ulnar R	2.1	21	2.2	8.4	56
Ulnar L	2.1	37	2.2	8	61
Tibial R			3.3	21.1	50
Tibial L			3.3	25	52
Peroneal R			3	5.5	51
Peroneal L			3.3	4.9	60
Superficial peroneal R	2.6	16
Superficial peroneal L	2.8	16
Sural R	2.3	21
Sural L	2.2	16

DSL: distal sensory latency, S Amp: sensory amplitude, DML: distal motor latency, M Amp: motor amplitude, NCV: nerve conduction velocity, R: right, L: left..

Table 2 . Latencies of Somatosensory Evoked Potential Study.

	P19 latency (ms)			P23 latency (ms)
	Right	Left		Right	Left
Median nerve	19.2	19.8		23.8	23.7

Table 3 . Results of the Needle Electromyography.

Muscle	Spontaneous			MUAP		Recruitment pattern
	Fib	PSW		Duration	Amplitude
APB. R	None	None		Normal	Normal	Normal
APB. L	None	None		Normal	Normal	Normal
BB. R	None	None		Normal	Normal	Normal
BB. L	None	None		Normal	Normal	Normal
PT. R	None	None		Normal	Normal	Normal
PT. L	None	None		Normal	Normal	Normal
C5 paraspinal R	None	None		Normal	Normal	Normal
C5 paraspinal L	None	None		Normal	Normal	Normal
C6 paraspinal R	None	None		Normal	Normal	Normal
C6 paraspinal L	None	None		Normal	Normal	Normal
C7 paraspinal R	None	None		Normal	Normal	Normal
C7 paraspinal L	None	None		Normal	Normal	Normal

Fib: fibrillation, PSW: positive sharp wave, MUAP: motor unit action potential, APB: abductor pollicis brevis, BB: biceps brachii, PT: pronator teres, R: right, L: left..

Herein, the patient had a history of cervical spondylosis and C4-5 disc herniation. A combination of forced rotatory and extension maneuvers executed during cervical spine manipulation seemed to have caused an extreme excursion of the vertebrae, which can manifest in the form of direct contusion and-/or ischemia of the spinal cord.⁹ Thrust is contraindicated in patients with central disc herniation.⁶ If the patient had approached a musculoskeletal specialist, he would have been recommended alternative treatment modalities or surgery other than thrust, and the above disaster could have been prevented. This case suggests the role that should be played by doctors in situations, where the number of claims for actual expenses and those for complaints of manual treatment are increasing every year. Doctors, particularly musculoskeletal specialists, must be completely functional in all areas of manual therapy. First, subjective and objective evaluations should precede manual therapy for patients. Absolute contraindications to manual therapy or red flag groups must be identified after considering the patient’s complaints, previously diagnosed diseases, family history, physical examination and imaging tests and must be performed under the guidance of a doctor. Symptoms that arise during or after treatment must be addressed by the doctor through prompt and appropriate measures, thereby ensuring the patient’s recovery. Finally, in the event of the occurrence of adverse events (AEs), the doctors should reduce the incidence of complications in the future through active accident reporting.

Flexion and extension movements of the cervical spine involve sliding movements of a vertebra over the one below it, and normal flexion or extension reduces the anteroposterior diameter of the cervical canal. Meanwhile, in a previous case reported by Murphy et al.,¹⁰ a patient with a cervical disc problem progressed to cervical myelopathy naturally, even without manipulation. Hence, in patients with stenosis of the spinal canal or vertebral instability, cervical SMT can lead to severe cord injury. Acute fracture, acute soft tissue injury, dislocation, osteoporosis, vertebral instability, and vertebral artery abnormalities are some of the other contraindications to manipulation. Smoking, cervical trauma, recent infection, hypertension, migraine, a low cholesterol level, and a low body mass index are the additional risk factors associated with AEs.¹¹ Previously, it has been reported that strictly excluding patients with known contraindications and red flags from receiving manipulation could reduce AEs by 44%.¹²

SMT can generally be performed for various etiologies of neck and lumbar pain, if not contraindicated. A limitation in normal joint movement is called a restriction barrier. Use of hands to eliminate these barriers can help restore the normal range of motion. Thrust and mobilization are useful, but there are other techniques, such as soft tissue technique and direct myofascial release, and appropriate treatment is decided by the physical therapist. There are other considerations to reduce complications. Currently, the prevalence of AEs following SMT has not been clearly established. Assendelft et al.¹³ reported that post spinal manipulation complications are usually underreported, owing to the inability of the physician to recall the cases, leading to misses of minor cases. Moreover, in Korea, treatment modalities, such as Chuna therapy, chiropractic treatment, and manual therapy, are mixed and have an underdeveloped complication reporting management system. Clarifying the concepts of manual therapy and allowing it to be performed by a qualified therapist can help manage the risk.

Only seven cases of complications arising from SMT have been reported in Korea, as evident from the Korea Citation Index and journals related to manual therapy, including Annals of Rehabilitation Medicine and Clinical Pain. These cases have reported central retinal artery occlusion, posterior inferior cerebellar artery infarction, vertebral fracture, accessory nerve injury, cauda equina syndrome, atlantoaxial subluxation, and myelopathy as complications of cervical SMT.^11,14-19 Compared to the previous domestic report, the case of our patient was not a rare one; however, he already had cervical spondylosis, C4-5 herniated disc, multilevel disc bulging and cervical foraminal stenosis due to uncovertebral joint hypertrophy, contraindicating manual therapy. Through this case report, we emphasized the importance of a physician’s role as a commander and reiterated the importance of recognizing contraindications and indications of SMT.