Stroke: A Complication of Stellate Ganglion Block


1. Patient reports pain that is disproportionate to that which is expected given the injury

2. Subjective symptoms (must report 3 of 4 categories)

Sensory

Hyperesthesia

Allodynia

Vasomotor

Temperature asymmetry

Skin color changes

Skin color asymmetry

Sudomotor/edema

Edema

Sweating changes

Sweating asymmetry

Motor/trophic

Decreased range of motion

Motor dysfunction (weakness, tremor, dystonia)

Trophic changes (hair, nail, skin)

3. Objective signs (must exhibit 2 of 4 categories)

Sensory

Hyperalgesia

Allodynia

Vasomotor

Temperature asymmetry

Skin color changes

Asymmetry

Sudomotor/edema

Edema

Sweating changes

Sweating asymmetry

Motor/trophic

Decreased range of motion

Motor dysfunction (weakness, tremor, dystonia)

Trophic changes (hair, nail, skin)

4. No other diagnosis better explains the signs and symptoms





19.2.1.3 Subtypes of CRPS


The first subtype of CRPS patients have a fairly limited pain component to their syndrome and have strong vasomotor signs as the main concern. The second type is also relatively limited, respectively, in terms of pain and demonstrates neuropathic pain/sensory abnormalities as the principal feature. The third and most functionally limiting subtype is the most similar to the classic descriptions of reflex sympathetic dystrophy wherein the patients have very severe pain and are extremely limited in functional status [4].



19.2.2 Treatment


The input of multiple different therapists and use of multimodal analgesic medications are two mainstays of the treatment plan for a patient with CRPS. The concept of functional restoration has always been a foundation of treatment for patients that have CRPS. Outside of actual reduction in reported pain score, functional recovery is often considered the most critical component of interdisciplinary pain management programs for CRPS. Various types of therapy are employed, and the therapists may use multiple techniques to achieve treatment goals. Outside of these less invasive treatments, several procedures exist that often ease the pain of CRPS and may be used concomitantly with medications and therapies for optimum benefit. It has long been established that optimal treatment of neuropathic pain and CRPS is through multimodal treatment that includes behavioral and physical therapies, pharmacotherapies, injection therapy, and psychotherapy, if indicated [1, 5, 6].


19.2.2.1 Therapies


Reanimation : The concept of emphasizing physical activity in the patient, given that commonly patients with CRPS are reluctant to move or permit manipulation of their affected limb, is vital to rehabilitation. As a corollary to this, immobilization is a poor prognostic sign, and pain programs must emphasize movement in CRPS patients as even healthy individuals will develop pain symptoms after prolonged immobilization [7]. Several therapy techniques aid in achieving reanimation.

Physical therapy: PT has long been a critical component of functional restoration, but it is used in conjunction with other therapies. It is often a first-line treatment of CRPS, and concomitant sympathetic nerve blocks may be used to improve the ability of the patient to participate in physical therapy and regain function [8]. PT may be intensive and can include desensitization, aerobic physical therapy, or hydrotherapy. Often it is supplemented by cognitive behavioral therapy. This has been shown to be particularly effective in treating childhood CRPS, reducing the rate of long-term dysfunction [9].

Graded motor imagery : This is one of the therapies with very strong evidence from multiple clinical trials that support its efficacy in CRPS patients. Graded motor imagery exercises are mental in nature and consist of three different components [10]:


  1. 1.


    Laterality training : The patient is presented with a picture of a limb and will answer as quickly as possible as to the laterality and view of the limb shown in the image. These can range in difficulty, from a completely visible limb to one that is almost entirely obscured or out of frame.

     

  2. 2.


    Explicit motor imagery : The therapist will show the patient an image of a healthy limb executing an activity that the patient is unable to perform. The patient is encouraged to imagine performing the activity. This can be quite traumatic for patients with severe CRPS; therefore, it is recommended to start with an unaffected limb and to move from a proximal point to a more distal point on the extremity.

     

  3. 3.


    Mirror feedback therapy : Patient will be seated such that a mirror is at the midline of their body obstructing the view of the affected limb and reflecting a mirror image of the benign limb. The patient is then encouraged to move the healthy limb, and due to neuroplasticity the brain can better adapt to the affected limb performing the same movements without pain.

     

These three components used for an intensive 2-week period can reduce pain in a statistically significant manner even in patients with long-standing intractable CRPS [11].

Occupational therapy : Occupational therapists (OTs) will evaluate the patient’s initial active range of motion, edema, coordination, dexterity, and ability to use the extremity during activities of daily living. This therapy may also utilize mirror visual feedback in an attempt to desensitize the patient to performing normal activities. Additionally, OTs often use a stress-loading program to improve the patient’s ability to use the affected limb for activities requiring strength or contact with substances causing pain [12]. In severe cases of CRPS, e.g., subtype 3, patients may need desensitization therapy with OT in order to tolerate the touch of clothing on the affected skin surfaces. If the patient is limited in even relatively benign activities due to pain, a sympathetic nerve block may assist in enabling the patient to participate in therapy [13].

Recreational therapy : In particularly recalcitrant cases of CRPS, recreational therapy is an attractive option to engage the patient in activity to break their phobia of movement or contact. If planned appropriately, recreational therapy may incorporate the goals of the physical therapist and occupational therapist [14].

Vocational rehabilitation : This is an advanced level rehabilitation therapy in which the patient is prepared for return to work. Alternatively it is termed “work hardening.” The vocational rehabilitation specialist must work closely with the patient to fully understand the physical demands of the patient’s prior occupation. Although it is utilized late in the rehabilitation process, vocational rehabilitation should also be addressed early on to ensure that the final goal of return to work is constantly the focus of the patient’s therapeutic process. The therapist may also work with the patient’s employer in an attempt to optimize the workplace for any new limitations the patient may possess [15].


19.2.2.2 Medications


A handful of medications have been evaluated in randomized controlled trials (RCTs) specifically for use in CRPS, but the majority of medications prescribed for the disease state have only been evaluated in other neuropathic syndromes.


Anti-inflammatory Drugs

Oral corticosteroids have level 1 evidence demonstrating benefit in CRPS. However, these trials typically took place in early acute cases of the disease, at which time inflammation is a common pathophysiologic factor [16]. There are no trials regarding corticosteroid use in chronic CRPS. Other nonsteroidal anti-inflammatory medications (NSAIDs) have only been trialed in neuropathic pain and only in small clinical trials. Specific NSAIDs may be more beneficial in treating CRPS, an example of this being ketoprofen. Celecoxib, a COX-2 inhibitor, and infliximab, a tumor necrosis factor inhibitor, both have some degree of evidence demonstrating their efficacy in CRPS [17, 18].


Antiepileptic Medications

Gabapentin has shown efficacy in the treatment of neuropathies and has strong anecdotal evidence regarding its benefit in CRPS patients [19]. Carbamazepine showed considerable benefit in a randomized controlled trial when used in doses of 600 mg per day for an 8-day course in patients with CRPS [20]. Other related medications such as oxcarbazepine, phenytoin, and lamotrigine also showed some benefit in neuropathic processes but are not as widely prescribed for CRPS [1].


Antidepressants

Tricyclic antidepressants are among the most widely prescribed medications for neuropathic conditions. Although they have not been specifically studied for CRPS, multiple RCTs support their use in neuropathies, and as a consequence they are widely prescribed for CRPS [21]. Serotonin/norepinephrine reuptake inhibitors have shown some benefit in neuropathies, but none have been studied in CRPS patients. Selective serotonin reuptake inhibitors do not show analgesic benefit in any pain state, neuropathic, or otherwise [1].


N-Methyl-d-aspartate (NMDA) Receptor Antagonists

Ketamine is often prescribed for CRPS, either in oral or IV form. Currently level 4 evidence exists for its use in CRPS [22, 23], but its widespread use is limited by its abuse potential and toxicity at therapeutic doses. Ketamine has shown benefit in both oral form and after IV infusion [24].


Opioids

Opioids are not typically recommended for CRPS. Few randomized controlled trials exist, but given the neuropathic nature of CRPS, the disease state does not seem to respond to opioid therapy as reliably as patients with nociceptive pain. When considering opioid therapy for a CRPS patient, optimal choices include methadone or tramadol, due to the NMDA antagonism and serotonin/norepinephrine reuptake, respectively, of the two agents [22, 23].


Topical Analgesics/Local Anesthetics

Capsaicin cream has shown promising results when used topically in areas affected by CRPS, but given that it causes an initial burning pain prior to the desensitization of the nerve fibers, patient adherence tends to be poor. Lidocaine and clonidine are also prescribed as they have shown pain benefit in neuropathic conditions; however, they have not been studied expressly in patients with a CRPS diagnosis [18]. Similarly, although not studied in CRPS, IV lidocaine has also been shown to reduce hyperalgesia and allodynia in patients with neuropathic pain [5].


Antihypertensives

Nifedipine , a calcium channel blocker often used for cardiac disorders, has demonstrated weak evidence for utility in management of CRPS. Clonidine, which is a more common medication for pain states, is an alpha-2 adrenergic agonist and has shown no benefit in CRPS according to a systematic review [16].


Anti-osteoporotic Medications

Calcitonin , which is produced by the thyroid and is instrumental in bone growth, has been shown in several randomized controlled trials to improve pain scores in CRPS patients. However, other trials have revealed conflicting results. Bisphosphonates , another medication commonly used to treat osteoarthritis, slows bone resorption and has shown significant improvement in pain in CRPS patients. Although level 2 evidence supports the use of bisphosphonates for pain in CRPS, the effect of the drug on the symptom of osteopenia that so commonly accompanies late-stage CRPS has not been studied [1].


Intravenous Immunoglobulin

Immunoglobulin G is a human blood product component that consists of immunomodulating peptides and antibodies that act against not only exogenous antigens but also many normal human proteins. Intravenous immunoglobulin G has been shown to decrease pain scores when administered to patients with CRPS [25].


19.2.3 Stellate Ganglion Block



19.2.3.1 Anatomy


Fusion of the inferior cervical and first thoracic ganglia forms the stellate ganglion, which is only present in 80% of the population and provides sympathetic innervation to the upper extremities, head, and neck. With a pure stellate ganglion block, a majority of the sympathetic nerves of the upper extremity will be blocked, but anomalous pathways exist that bypass the ganglion. These pathways, known as Kuntz’s nerves , are responsible for the incomplete nature of sympathetic blockade if a pure stellate ganglion block is performed without blockade of the second and third thoracic ganglia [26]. The stellate ganglion itself is usually 1–2.5 cm long, 1 cm wide, and 0.5 cm thick near the level of the C7 vertebrae. Although its location may vary, it is most often at the lateral border of the longus colli muscle (LCM) in the region anterior to the first rib and posterior to the vertebral vessels [27]. Therefore, the stellate ganglion is located in close proximity to various fragile soft tissue structures, which is responsible for the increasing popularity of ultrasound guidance as compared to the blind or even fluoroscopic techniques. Vulnerable soft tissues in the vicinity of the stellate ganglion include the esophagus, recurrent laryngeal nerve, pleural space, subarachnoid and epidural spaces, thyroid artery, and vertebral artery.

The vertebral artery consists of four segments . The first section stems from the subclavian artery and travels superiorly to the transverse foramen of the C6 vertebral body. At this point, the second segment begins and passes through the transverse foramina of C6–C2 vertebral bodies. The C2 level delineates the beginning of the third segment of the vertebral artery, which exits the C2 foramen and courses posteriorly to enter the dura at the foramen magnum. The fourth portion of the vertebral artery is entirely intracranial and spans from the foramen magnum to the basilar artery, where it joins the contralateral vertebral artery [28]. SGB requires needle manipulation in a position that is very near in the second segment of the vertebral artery. As this artery has wide anatomic variability, the distribution of stroke symptoms may differ for any patient that suffers an injury. However, the insult may fall into two broad categories: (1) CNS toxicity from direct injection of local anesthetic to the blood supply or (2) vertebral injury/spasm causing decreased blood flow to critical central nervous system structures.

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Feb 26, 2018 | Posted by in Uncategorized | Comments Off on Stroke: A Complication of Stellate Ganglion Block
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