The sequela of spinal cord injury (SCI) affects millions
worldwide. We present a case of a 60-year-old male with a SCI, who
experienced functional improvement and a significant reduction in pain
following spinal cord stimulation (SCS) treatment. This promising
outcome suggests SCS could be a future cornerstone in SCI management.
INTRODUCTION
Spinal cord injury (SCI) is a serious medical condition that leads to
significant morbidity and mortality. In the United States alone, there
are approximately 300,000 people living with SCI, and about 17,000 new
cases are reported each year with a cost of almost $10 billion annually1. Approximately two-thirds of SCIs are incomplete
injuries, where some neural activity still remains below the lesion,
thus preserving partial function. Unfortunately, studies have reported
that even in patients with incomplete SCI, there is a substantial
decrease in quality of life following their injury, along with a
significant reduction in life expectancy 2,3.
The outcome of a SCI varies depending on the location and degree of
neurological damage. Some complications, such as the motor spasticity
seen in our patient, affects 65–92% of people with chronic SCI and is
more common with higher levels of injuries 3,4,5.
Spasticity is a velocity-dependent increase in muscle tone associated
with upper motor neuron (UMN) injuries 6. The damaged
UMN leads to a loss of inhibitory signals in the descending spinal
tracts, resulting in increased stretch reflex and muscle tone7. Spasticity typically begins to develop several
weeks or months after injury as the period of areflexia begins to
subside 8 and can lead to pain, discomfort, and
complications with significant functional impairment, further
contributing to decreased quality of life for patients6, 2.
Epidural spinal cord stimulation (SCS) is a neuromodulation technique
that places electrodes within the epidural space of the dorsal column to
deliver mild electrical impulses. Although SCS has traditionally been
employed as a treatment for chronic pain, recent research suggests its
potential usefulness for other medical conditions as well. A 2022
systematic review found that SCS could be beneficial in restoring
sensorimotor function, including volitional movement, after SCI. The
total participants included 327 patients with SCI, and of the studies
assessing sensorimotor function, 71/127 (56%) of patients regained
volitional movement during SCS 9. In addition, a 2024
systematic review analyzed thirty-four studies for spasticity
improvements with the use of SCS. A subset of their data looked
specifically at subjective improvement in spasticity after spinal cord
injury, where 190/281 (68%) of patients found improvement in their
symptoms after SCS 10. This data shows that
neuromodulation holds promise as a tool that may enhance patients’
functional recovery in conditions beyond pain such as SCI and assist
activity-based recovery. In this case report, we hope to add to this
potential by presenting a patient who had a long-standing history of
pain and spasticity as a result of SCI, and found impactful improvements
with the use of spinal cord stimulation.
CASE HISTORY
A 60-year-old male with a history of traumatic cervical SCI secondary to
a ski accident presented to the pain management clinic with chronic
spasticity and neuropathic pain of the right upper extremity (RUE) and
bilateral lower extremities (BLE). The patient had previously found
minimal relief with conservative management and chemodenervation with
botulinum toxin. Physical examination demonstrated increased tone in his
RUE, resulting in loss of function, along with complaints of paresthesia
and numbness in his BLE. After thorough testing according to the
International Standards for Neurological Classification of SCI
(ISNCSCI), the patient’s injury was classified as C5 AIS D.
METHODS
The patient was agreeable to trying other treatment modalities and
subsequently underwent a spinal cord stimulation (SCS) trial, with
cervical and thoracic leads placed to cover mid-C3-C5 and mid-T9-T11,
respectively. This trial revealed a significant improvement in the
patient’s right-sided neuropathic pain, demonstrating a greater than
70% reduction in symptoms. This positive outcome supported the
continuation of the current treatment strategy, leading to the scheduled
implantation of a SCS.
During the SCS implant, two 8-contact spinal cord stimulator leads were
inserted and advanced under AP and lateral fluoroscopic guidance into
the posterior epidural space. The left lead was advanced to the level of
C5, and the right lead to the level of C4 (Fig. 1). The thoracic leads
were placed midline at the level of the T11 vertebral body (Fig. 2). The
placement of the leads within the posterior epidural space was confirmed
with lateral fluoroscopy (Fig. 3). Intraoperative paresthesia
stimulation confirmed adequate coverage of the pain areas, and the leads
were anchored and battery placed in a typical fashion. The patient was
awake and conversant throughout the procedure.
CONCLUSION AND RESULTS
Two weeks post-procedure, the patient reported improvement in his hand
spasticity and neuropathic pain. Neuropathic pain in the feet was mostly
masked by the stimulator. However, he was still able to notice it and
adjust settings for better coverage. Subsequent weeks involved several
programming adjustments to optimize pain management and spasticity
reduction. These adjustments led to the restoration of the patient’s
previously impaired right elbow extensor motor function, achieved with a
frequency of 2Hz, a pulse width of 550 ms, and an intensity of 5 amps.
The patient reported a 60% improvement in spasticity and complete
alleviation of pain, rating it at 0 out of 10. The patient approved the
reporting of this case and results.
DISCUSSION
Spinal cord injury can have devastating consequences for patients,
affecting their physical, psychological and social well-being11. Common impairments associated with SCI are loss of
motor and sensory function, bowel and bladder dysfunction, recurrent
infections, autonomic dysreflexia, spasticity, contractures, and chronic
pain. These impairments can also impose a significant financial burden
on patients, who may incur costs ranging in the millions over their
lifetime for SCI-related care 12. The main goal of SCI
treatment is to help patients enhance their functional abilities,
mitigate pain, and ultimately cope with their condition in the best way
possible.
Current treatment strategies for post-SCI spasticity involve multimodal
strategies and a multidisciplinary approach. Initial treatment is
typically conservative with passive muscle stretching and physical
therapy, pharmacologic agents (tizanidine, benzodiazepines),
onabotulinumtoxinA injections, or even surgical interventions (e.g.,
dorsal rhizotomy). Baclofen can additionally be administered through an
intrathecal baclofen pump (ITB), providing sustained bolus release of
the medication for spasticity management. While these treatment options
are widely used, they come with limitations, including undesirable
adverse effects, treatment resistance, and inconsistent results.
Technological advances have allowed for the development of minimally
invasive techniques that can advance patient care and expand available
treatment options. In 1967, by way of the “Gate Control Theory”, it
was postulated that the introduction of an exogenous electrical signal
can potentially modulate the endogenous pain signals that coalesce
within the dorsal column. Even though the exact underlying process of
how SCS enhances functional recovery remains somewhat unclear at this
time, the prevailing hypothesis is that the constant stimulation of
afferent fibers in the dorsal root elevates the overall excitability of
spinal circuits, making interneurons and motor neurons closer to their
firing threshold and physiological state 13. These
effects enable these neurons to respond more effectively to the
diminished inputs after an injury, thus increasing synaptic strength and
plasticity. Although the mechanism is not fully understood, there is
growing evidence that the suppression of motor neuron hyperactivity can
also improve spasticity in patients with SCI 14.
Ongoing pathophysiologic research is needed to explain the underlying
mechanism, but select patients are already experiencing tangible
benefits from this treatment option.
SCS for improving spasticity after SCI is an emerging technology showing
positive results overall 10, 15. Although SCS is
regularly studied in other uses, such as chronic pain, further
literature is needed to continue the establishment of additional
indications for the treatment modality. This case report illustrates the
remarkable benefits of SCS for a patient with an incomplete AIS D SCI.
After receiving SCS, he reported significant reductions in hand
spasticity and neuropathic pain, as well as enhanced motor function and
range of motion in his right arm. We hope that this case study helps
provide evidence that spinal cord stimulators have the potential to
positively impact the lives of patients with multiple ailments.
While there is emerging evidence of the potential role of SCS as a
treatment modality for UMN-lesion-induced spasticity, more research is
needed to assess efficacy, optimal stimulation parameters, and proper
patient selection. With the advent of new technologies that can measure
neural feedback during stimulation and the supraspinal/cortical changes
occurring in addition to analgesia, there may be a lot more to be
uncovered with future investigations.
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