Effects of dry needling on muscle spasticity of the upper limb in a survivor of traumatic brain injury: a case report

Spasticity as one of the symptoms of upper motor neuron syndrome is characterized by a speed-dependent increase in muscle tone caused by excessive excitability of the stretching reflex [1]. Spasticity is mostly considered a neural lesion because the primary lesion leading to spasticity is located in the central nervous system. Recently, attention has been drawn to the structural and functional changes in skeletal muscle that occur secondary to spasticity. Studies have reported decreased mitochondrial volume fraction, appearance of intracellular amorphous material, reduction in muscle fiber length, and decrease in the number of serial sarcomeres within fibers of spastic muscles [2, 3]. Multiple therapeutic interventions including stretching, casting, splinting, pharmacologic treatment, botulinum toxin injection, and electrical stimulation of the muscles have been tried for abating spasticity that mostly involves the peripheral nerves and muscles [4‐6]. Dry needling (DN) is a relatively new promising intervention that has been shown to control spasticity following stroke [7, 8]. It is assumed that DN not only decreases the spasticity by affecting contractile properties of spastic muscles [9] but also has modulatory effects on neural activity of the spinal circuit [10], supraspinal, and higher centers [11, 12].

Spasticity is a common condition among survivors of traumatic brain injury (TBI), and occurs in up to 20% of patients with moderate-to-severe TBI [13]. Up to 20% of patients with TBI develop an acute subdural hematoma [14], a condition that may be associated with contralateral spastic hemiplegia, a lesion whose physiopathology is similar to that of brain lesions of vascular origin [15]. When a lesion of the brainstem is involved, spasticity becomes more pronounced [16]. Spasticity occurs more commonly in upper limbs than lower limbs [17]. Upper limb function is severely compromised by spasticity owing to decreased range of motion, decreased voluntary strength, and increased joint stiffness [18, 19]. The aim of this case presentation is to evaluate the immediate effect of a DN session on a patient with left hemiplegia after TBI, who suffered from spasticity of the upper limb.

The patient was a 27-year-old Iranian man surviving from severe TBI following a motor vehicle accident, with left hemiplegia and spasticity of the upper and lower limbs (lower limb spasticity less severe than upper limb), especially in the wrist flexors, pronator, and thumb adductor and flexor muscles. The patient had no history of any comorbid conditions such as cardiovascular disease, diabetes, or high blood pressure. He had started to walk independently and without support 8 months after injury. He had received several other treatments, including physiotherapy, exercise therapy, medication, and botulinum toxin injections to relieve spasticity of the upper limb, but still complained of spasticity and dysfunction in the left upper limb. We aimed to evaluate the immediate effect of a single session of DN on this patient with left hemiplegia after TBI, who suffered from spasticity of the upper limb. The study was approved by the research ethics committee of Shiraz School of Rehabilitation Sciences.

After a single session of DN, the patient’s upper limb recovery stage and hand function improved from 4 to 5 according to Brunnstrom recovery stages. Spasticity was assessed using MMAS in the elbow flexor, wrist, and finger flexors, and thumb flexor/adductor showed one-grade abatement in all except forearm pronator. PRF decreased in all movements that were measured except in forearm supination. Both AROM and PROM increased in all movements that were measured except in active and passive forearm supination. Also, hand dexterity, which was measured by BBT, improved in both affected and unaffected hands. Table 3 presents the pre- and post-intervention results.

Spasticity is an uncompromising sequela of some neurologic diseases, including TBI, that is quite difficult to manage. Not only is this nettlesome for patients and negatively affects their function, especially upper limb function, but it is also a challenging problem for therapists working with these patients because spasticity can blunt the rehabilitation process. Therefore, controlling and mitigating spasticity is a therapeutic priority. Spasticity, a motor disorder associated with lesions of the central nervous system, is characterized by hyperexcitability of the stretch reflex due to disinhibition of cortical influences on spinal cord circuits resulting in a velocity-dependent increase in tonic stretch reflexes [28]. Spasticity is a neurological impairment resulting in structural changes and contractures in the muscles [29, 30] and, thus, increased stiffness of spastic muscle cells and tissue [2]. Dry needling is a common technique used by manual therapists to treat musculoskeletal disorders [31]. Recently, DN has emerged as a new option to treat muscle spasticity in neurological disorders such as post-stroke spasticity [32]. Some recent studies have provided evidence regarding the effectiveness of dry needles on abating spasticity [7, 8]. This case study aimed to evaluate the effects of DN in a patient suffering from upper limb spasticity post-TBI. Before DN intervention, the patient was able to combine some gross movement and deviate the synergies, and he had a small range of semi-voluntary finger extension, except thumb extension and abduction. After DN, he was able to combine more difficult movements as well as extend and abduct the thumb somewhat, in addition to voluntary extension of his fingers. This finding is similar to those reported in a previous study by Ansari et al. [8]. Significant improvement in hand functional outcomes after DN in patients with spasticity after stroke also has been proved neurophysiologically using H-reflex for α motor neuron excitability assessment [7]. In this case, spasticity after TBI showed one-grade abatement in almost all spastic muscles following DN, and consequently PRF against spastic muscles diminished. Our results are consistent with those of previous studies reported by Salom-Moreno et al. (2014) [33], Sánchez-Mila et al. (2018) [34] and Tavakol et al. (2019) [35], who also found a decrease in spasticity in the upper and lower extremities after a single session of deep dry needling. In contrast, Mendigutia-Gómez et al. (2016) found no change in spasticity in the shoulder muscles after dry needling [36]. In this patient, neither AROM nor PROM of supination changed after DN, which is in contrast with the results of Ansari et al. [8]. The lack of change in AROM and PROM may have been due to a contracture of pronators. However, the patient was able to cope with daily activities. The BBT as an indicator of manual dexterity improved after DN on the affected side, but also on the unaffected side. This may be explained as post-trial learning to some extent, as well as neural facilitation induced by DN [7], but this outcome needs further investigation. The main mechanism of DN-induced spasticity reduction is not fully understood, although there are several potential explanations. Since dry needles can reduce the stiffness of stretched bands [11], it can be assumed that dry needles can cause changes in spasticity by creating local tension release in the structure of shortened muscle fibers, as was shown in a patient with post-stroke spastic muscles [9]. Another potential explanation is related to the modulatory effects of DN on afferent and efferent neuron activity of the spinal circuit [10]. It seems that the local twitch responses elicited by DN can alter sensory spinal processing, then modulate α motor neuron excitability by modifying synaptic transmission and, therefore, decrease the excitability of spinal reflexes associated with muscle spasticity [37]. Furthermore, it is hypothesized that DN might also activate the noxious inhibitory control system by activating Aβ-fibres and Aδ fibres fibers sending afferent signals to the dorsolateral tracts of the spinal cord that could also activate the supraspinal and higher centers involved in pain processing [11, 12]. The activation of the noxious inhibitory control system following DN could have relaxing effects on the spastic muscles. The results of our study seem promising, though some potential limitations should be acknowledged. First, we collected short-term outcomes of a patient, while for accurate interpretation and generalization of the findings, it is necessary to evaluate larger samples of patients with spasticity, have a control group, and evaluate the outcomes with follow-up after treatment with DN. Second, it would be better to determine the effects of dry needling in combination with routine or other treatment options, as Cai et al. suggested that combining electroacupuncture with conventional treatment might be worthwhile in terms of muscle spasticity reduction, improvement of motor function, and return to activities of daily living [38]. Therefore, further research with a sufficient sample size, additional treatment sessions of DN, and combination with other treatment choices is suggested.

The results of this case report suggest that application of a single session of dry needling on the upper limb spastic muscle was effective at decreasing muscle spasticity and improving passive resistance force, upper limb recovery stage, and hand function and ROM in individuals who had experienced traumatic brain injury. Future studies with larger sample sizes, more treatment sessions, long-term follow-ups, and inclusion of other treatment options are needed.