Clinical Pearl: How I would treat spastic clenched fist deformity in a stroke patient

Introduction The clinical approach to the treatment of patients with spasticity is a complex balance between science and art, and should be part of a well-coordinated and comprehensive rehabilitation program that is patient-centric and goal-specific1. While there are a variety of therapies available for the treatment of spasticity, the challenge for clinicians is to optimize outcomes from the available management options1. By its very nature, spasticity treatment is not a single, isolated intervention but continues over the long term and progresses as the patient’s condition changes, and suboptimal outcomes following any treatment modality can have multiple etiologies2. As a result, the choice of a particular treatment for a given presentation can vary from patient to patient. In addition, treatment decisions are greatly influenced by individual circumstances, with factors such as experience, training, and locally available resources having a significant impact on how a clinician makes treatment decisions. Botulinum toxin injections are widely considered as effective and safe, with few cases of iatrogenic botulism often relating to systemic drug diffusion and characterized by generalized or focal weakness. However, when they occur, transient adverse effects disable patients who are often already vulnerable. Currently, the only remedy available is to wait for the toxin’s effects to pass. The duration of the clinical effects of the toxin and any associated adverse events is usually 2–3 months after injection. Such periods of waiting can aggravate a patient’s disability3. The purpose of this hypothetical patient case is to gain insight into approaching a treatment challenge commonly encountered in clinical practice and to understand contrasting approaches, particularly in terms of dosage and traditional techniques, thereby enhancing future care. More importantly, it will highlight how often these methods differ and underline the variety of potential options available. It is anticipated that the treatment approaches documented will lead to further dialogue and exchange of expertise. Hypothetical clinical case Thirty-four-year-old, left-hand-dominant patient with left hemorrhagic cerebral vascular accident (CVA) with right hemiparesis, which occurred 6 months ago. He presents with progressive right-hand tightness and pain onset over the last 2 months and has received multiple outpatient physical and occupational therapy visits without benefit (Figure 1).Figure 1: Clinical case—tightly clenched right hand (ventral).The fingers and thumb are tightly clenched and no longer fit into his resting hand splint. The hand is difficult to open to perform palm hygiene and has problems with pain and stretching (Figure 2). He reports no symptoms in the leg.Figure 2: Clinical case—tightly clenched right hand (dorsal).Treatment with oral baclofen was increased to 20 mg tid without improvement in symptoms. On exam, the fingers are fully flexed at the MCP, PIP, and DIP joints at rest with the thumb-in-palm posture of the first digit (Table 1). Table 1 - Clinical case—passive extension of the fingers. Joint Passive ROM (wrist in neutral position) MAS MCP −60 degrees 3 PIP −80 degrees 3 DIP −45 degrees 3 There is some maceration of the skin of the palm and a noted foul odor. He has no active movement of the fingers; sensation to light touch in the right hand and arm is intact. Learning objectives for this case Identify the muscles involved in the clenched fist. Develop an approach to differentiate spasticity from contracture. Identify pharmacological and nonpharmacological therapeutic options. Identify possible treatment goals for this pattern. What management approaches would you recommend? - Steven Escaldi Djamel Bensmail Department of Rehabilitation Medicine, JFK-Johnson Rehabilitation Institute, New Jersey, USA Department of Physical Medicine and Rehabilitation, R. Poincaré Hospital, Assistance publique—Hôpitaux de Paris, University of Versailles Saint Quentin, Garches, France Clinical factors driving treatment decisions Clinical factors driving treatment decisions The primary factors considered for treatment decisions are: time post-injury, symptom severity, current function, and treatment goals. Primary factors for consideration include pain, ROM limitations, and hygiene difficulties leading to discuss BoNT as a first-line treatment. Treatment goals Treatment goals Treatment goals are primarily passive: Three treatment goals comprise: • improved hand position; • improved comfort with PROM; • improved ease of hygiene; • ability to wear his hand splint. • pain decrease during mobilization; • hygiene facilitation; • no worsening of the fingers’ ROM. Pain decrease and hygiene facilitation will be evaluated using a VAS. The third goal will be assessed using the passive ROM of the finger joints (MCP, PIP, and DIP) Primary intervention Primary intervention Since he has already taken oral medication and performed therapy, primary treatment would be a BoNT injection to address the focal presentation. Our institution does not dictate toxin dosing, and FDA approval in the United States for ULS is 400 U for incobotulinumtoxinA and onabotulinumtoxinA, so dosing is clinically driven. Based on the presentation, injecting both extrinsic and intrinsic finger and thumb flexors would be anticipated (assuming there is no wrist muscle involvement). It is my preference to use EMG guidance for localization (alone or in combination with Ultrasound guidance), which allows for real-time evaluation of muscle activity and dosing adjustments while injecting the muscles involved in a presenting posture: a 1:1 concentration is my preferred dilution to address muscles of this size. I believe that the smaller volume allows more precise placement of the toxin into each individual fascicle of the muscle without extravasation. The increased number of injection sites allows the medicine to be placed in multiple locations along the length of the muscle. For injection site comfort, ice and/or topical lidocaine gel can be applied. Due to the availability of a 50 U vial (to minimize waste), incobotulinum is selected with a plan for 250 U total of incobotulinumtoxinA for the initial injection: 90 U to FDS (4 sites), 70 U FDP (3 sites), 20 U FPL (1 site), 20 U FPB (1 site), and 50 U allocated to lumbricals (3–4 sites). Typically, FPL, FDS, and FDP are the primary focus; the severity and fisted position that was reported in this case would lead me to add the lumbricals and FPB. As well as justification for a higher than labeled initial dosing In this case of severe disabling spasticity of the upper limb, oral treatments are not effective and do not allow us to reach the goals set. First-line treatment would include BoNT injections. We can use any formulation of BoNT (abobotulinumtoxinA, onabotulinumtoxinA, or incobotulinumtoxinA). In FDP (50 U), FDS (50 U), and FPL (40 U) of incobotulinum toxin or onabotulinum toxin. I use the same dosage for either incobotulinum or onabotulinum toxin. If using abobotulinum toxin, FDP (125–150 U), FDS (125–150), FPL (100–120 U). To have enough volume to inject all the muscle bundles, 100 U of incobotulinum and onabotulinum toxin should be diluted with 2.5 mL of saline. 300 U of abobotulinum toxin would be diluted with 3 mL of saline, as per the manufacturer’s instructions. Use either electrostimulation or sonography guidance is recommended to perform the injections. In case of dystonia or severe neuropathic pain associated with spasticity, sonography may be used because it is not always easy to stimulate a dystonic muscle and also to minimize pain during the injections. In the other cases, electrostimulation can be utilized for its ease of use. The FDS would be injected in 4 sites (each bundle representing the 4 digits). The FDP would be injected in 2 sites. The FPL would be injected in 1 site, but using the entire length of the needle to ensure the diffusion of BoNT. In case of neuropathic pain or great anxiety of the patient, nitrous oxide may be considered to improve the patient experience and reduce pain during the procedure. Expected outcomes Expected outcomes With the dose and muscles selected, it is anticipated that the resting position of the hand will be sufficient that the palm can be visualized and accessible to clean. It is hoped that the PROM for finger extension at the DIP, PIP, and MCP would be improved to at least −30 from full. WFL for extension at the thumb at the IP joint, −30 degrees at the MCP. • 50%–70% of pain decrease during mobilization; • hygiene facilitation (VAS = 5–7); • stabilization of passive fingers range of motion. Other treatment modalities Other treatment modalities Patient would be instructed in daily self-ROM exercises and hand splint use. Occupational therapy would be ordered in conjunction with the injection. Focus of therapy into providing proper fitting hand splint and maximizing ROM. Two therapy modalities that can be employed are local heating (moist heat/paraffin) before ROM activity (usually initiated 2 wk after injection). Physiotherapy 3 times per week Guided self-rehabilitation*4: everyday stretching of the fingers by the patient. Explain to the patient the self-rehabilitation program. 20 min of daily self-rehabilitation should be recommended to the patient. A few weeks after the injection session, review again to determine if the orthosis is suitable. Follow-up Follow-up Patient would be seen in 4–6 wk to evaluate the injection response as well as the response to the ordered therapy. Consultation 4–6 wk after the injection session • clinical evaluation; • assessment of proximal joints; • assess goal achievement; • discuss future treatments in terms of targeted muscles and dosing Considerations and approach for future treatments Considerations and approach for future treatments If there is a noted positive response, the patient can be scheduled for the next injection with a 90-day injection interval. Based on the follow-up exam, increased dosing (up to 400 U) would be determined, as well as changes in dose distribution and the need to address additional muscles. Goals can also be updated as warranted. Evaluate the indication of a splint and if the existing one is adapted or if modification is necessary. If there was minimal or no response, consider diagnostic medial and ulnar nerve blocks to determine extent of soft tissue contracture and to assist with consideration for surgical release. Of note, in an actual patient, this step can be considered the first intervention if the physical exam indicates that the soft tissue changes/tendon contractures were the primary restrictive component. OnabotulinumtoxinA is indicated for the treatment of upper limb spasticity in adult patients and supplied as single-use, sterile 50, 100, or 200 U vacuum-dried powder for reconstitution only with sterile, nonpreserved 0.9% Sodium Chloride Injection USP before injection5. Indication-specific dosage and administration recommendations of the manufacturer should be followed. The lowest recommended starting dose should be used, and ≤50 U per site should generally be administered. Localization of the involved muscles with electromyographic guidance or nerve stimulation techniques is recommended. In clinical trials, doses ranging from 75 to 360 U were divided among selected muscles at a given treatment session5. Dose should be selected based on muscles affected, severity of muscle activity, prior response to treatment, and adverse event history; electromyographic guidance is recommended by the manufacturer5. AbobotulinumtoxinA is indicated for the treatment of upper limb spasticity in adult patients and supplied as 300 or 500 U lyophilized powder in a single-use vial for reconstitution with preservative-free 0.9% Sodium Chloride Injection USP. The manufacturer’s recommended concentration is 100 or 200 U/mL: ≤1 mL should generally be administered at any single injection site. In the pivotal clinical trial, doses of 500 and 1000 U were divided among selected muscles6. Although the actual location of the injection sites can be determined by palpation, the use of injection guiding techniques (eg, electromyography, electrical stimulation) is recommended to target injection sites by the manufacturer6. IncobotulinumtoxinA is indicated for the treatment of upper limb spasticity in adult patients and supplied as 50, 100, or 200 U lyophilized powder in a single-dose vial. The manufacturer’s recommended total dose is up to 400 U, divided among affected muscles. The maximum recommended dose is 8 U/kg, divided among affected muscles, up to a maximum dose of 200 U per single upper limb7. Localization of the involved muscles with electromyographic guidance, nerve stimulation, or ultrasound techniques is recommended by the manufacturer7. • * Guided self-rehabilitation contracts are a diary-based strategy comprising a moral agreement between patient and physical therapists, where the therapist prescribes self-stretching techniques involving static postures at high load interchanged with rapid alternating movements of maximum amplitude to gradually reduce antagonist co-contraction4. Figures 3 and 4 indicate the anatomy of the forearm and hand.Figure 3: Muscles of the (A) forearm, (B) wrist, and (C) hand. Image from https://musculoskeletalkey.com/the-forearm-wrist-and-hand-3/, accessed January 4, 2025.Figure 4: Muscles of the hand. Image from: https://anatomyinfo.com/hand-muscles/ accessed January 4, 2025.How would you treat this case? Treatment of spastic clenched fist presents significant challenges for the management of individuals with post-stroke spasticity. The approaches proposed by Dr Escaldi and Professor Bensmail share common goals and the use of BoNT, but they differ in their specific dosages. As the reviewing author, what stands out is the choice to inject 4 sites into the FDS, including each fascicle. Typically, injection into 1–2 sites is used to minimize pain and discomfort. This raises the question whether multiple injections are more effective for spreading the toxin to muscle motor end plates, or if medication is placed across different sites within the muscle using a single skin puncture. In addition, the number of treatment cycles applied may have differing benefits when considering passive and active measures of spasticity. Randomized, double-blind, placebo-controlled comparisons suggest differing patterns of effect, where multiple injection cycles are required to attain maximal treatment efficacy; maximal benefits to passive measures were observed after 2–3 injection cycles compared with 4 cycles for active measures8. Another interesting difference is the dilutions used by my colleagues—1:1 and 2.5:1. This leads to consideration of whether Dr Escaldi used a higher, off-label dosage with a more concentrated formula, necessitating multiple injection sites. Such insight may influence best practice when injecting extrinsic finger muscles and could be something for readers to consider. Lastly, while the focus is on the clenched fist, neither physician discussed injections into wrist flexors or proximal muscles. It is possible that spasticity and pain in these areas contribute to the clenched fist. Colleagues are invited to share their management approaches for this hypothetical clinical case by submitting a letter to the editor. CRediT author statement Escaldi : Conceptualization, Investigation, Writing - Original Draft, Review and Editing, Bensmail: Conceptualization, Investigation, Writing - Original Draft, Review and Editing, Verduzco-Gutierrez: Conceptualization, Investigation, Writing - Original Draft, Review and Editing, Francisco : Conceptualization, Investigation, Writing - Original Draft, Review and Editing. Declaration of competing interest D.B. is a consultant for MERZ, Medtronic, IPSEN, and AbbVie. S.E. has received a consulting honorarium from Merz; M.V.-G. has been a consultant for AbbVie, Merz, Ipsen, and Piramal; G.E.F. has been a consultant to AbbVie, Merz, and MicroTransponder, Inc., and has received research grants from AbbVie, Merz, Microtransponder, Ottobock, and Revance Therapeutics. The funders of Toxnet had no role in the writing of the manuscript or in the decision to publish the manuscript. Funding The Toxnet group is supported by Merz Therapeutics GmbH. The medical writing for this manuscript was funded by Merz Therapeutics GmbH and provided by Allan Johnson and Brenda McCleary. None of the authors were paid for contributing to this manuscript. Ethics statement None. Data availability statement None. Acknowledgments The authors thank Aughrim Consultancy Ltd for support in facilitating manuscript preparation. The illustrations in Figure 1 and 2 were supplied by Merz Therapeutics LLC. Declaration of generative AI and AI-assisted technologies in the writing process No AI tools/services were used during the preparation of this work.