Focal Muscular Vibration in Patients With Severe Acquired Brain Injury

Focal Muscular Vibration in the Intensive Treatment of Spasticity in Patients With Severe Acquired Brain Injury

Severe acquired brain injury (sABI) is a group of disorders that cause long-term disability. Rehabilitation is essential to counteract bed immobilization, muscle failure, pain, and sensory deficits that can affect the clinical and rehabilitation pathway of these patients. Focal muscle vibration (FMV) is a tool that uses low-amplitude, high-frequency vibrations that when applied to muscle-tendon units. This technique, administered at specific frequencies, amplitudes and durations, can generate action potentials of the same frequency as the stimulus applied to the muscle or tendon. This makes it possible to activate selected afferent fibers and stimulate targeted brain areas with persistent effects over time (long-term potentiation). Regarding the effect of counteracting vibration spasticity, FMV is able to inhibit the reflex arc and induce reciprocal inhibition of functional agonist muscle. In addition, the strong proprioceptive stimulus generated by vibration is able to reach the primary motor and somatosensory cortex, enhancing cortical mechanisms that regulate co-contraction between agonist and antagonist muscles, thereby reducing muscle tone and joint stiffness. In many studies, this technique has been shown to be effective in reducing pain and joint stiffness by improving muscle contraction and motor control.

The present study aims to analyze the effects of focal muscle vibration in patients with sABI. This study is innovative for the setting, as it will take place for the first time within a neurorehabilitation hospital ward, for the intensity of the treatment as patients will undergo daily treatment sessions, for longer periods than protocols so far in the scientific literature. Finally, the cortical effects of the vibratory stimulus will be analyzed through the analysis of cortical neurophysiological correlates

Patients allocated in the G-FMV, in addition to conventional rehabilitation treatment, will be treated for 3 weeks with FMV, applied to the upper and/or lower limb, depending on the clinical status. The G-FMV will perform the treatment at a frequency of 7 times per week for 3 weeks (21 total applications), using the "EVM EVO medical device" (Endomedica, Italy), applying an intensity of 100 Hz for a total of 23 minutes. Specifically, four different trains of stimulation lasting 5 minutes each will be performed, interspersed with 1 minute of rest (20 minutes of treatment + 3 minutes of rest). FMV will be applied on agonist (major spasticity) muscles of the lower limb and/or upper limb, either single-district or multiple-district, according to clinical evidence of intervention. Stimulation will be conducted in a stand-alone session as an adjunctive modality to the rehabilitation project of physiotherapy and occupational therapy.

Patients allocated in the G-CONwill be treated for 3 weeks by specific conventional rehabilitation based on the clinical status. The G-CON will carry out the normal physiotherapy and occupational therapy rehabilitation treatment, as per the rehabilitation project, for an equal total treatment time to the G-FMV. Conventional treatment will focus on joint mobilization, muscle stretching, and neuromuscular facilitation activities, using the main rehabilitation methods (e.g., neurocognitive theory, Bobath Concept, Progressive Neuromuscular Facilitation, etc...)

FMV will be applied 7 times per week for 3 weeks (21 total applications), using the "EVM EVO medical device" (Endomedica, Italy), applying an intensity of 100 Hz for a total of 23 minutes.

Conventional treatment will focus on joint mobilization, muscle stretching, and neuromuscular facilitation activities, using the main rehabilitation methods (e.g., neurocognitive theory, Bobath Concept, Progressive Neuromuscular Facilitation, etc...)

The Modified Ashworth Scale (MAS) is a scale for the assessment of spasticity consisting of 6 different categories, based on the score assigned in relation to the degree of perceived resistance to passive mobilization.

The Disability Rating Scale (DRS) is a assessment tool through which the degree of disability can be assessed. The DRS consists of 4 categories through which a patient's functional level can be identified. For the category "vigilance and responsiveness" can be scored from 0 to 12, for the category "cognitive skills for self-care" the score ranges from 0 to 9, for the category "dependence on others" from 0 to 5, and for the category "social participation" the score ranges from 0 to 3. The total DRS score ranges from 0 (no disability) to 29 (severe vegetative state).

The modified Barthel Index (mBI) is a scale used to assess autonomy in activities of daily living. It consists of 10 items: "feeding," with a score ranging from 0 to 10; "personal hygiene," with a score ranging from 0 to 5; "bathing or showering," with a score ranging from 0 to 5"; "dressing,",on a score ranging from 0 to 10; "bed/chair transfer," with a score ranging from 0 to 15; "toilet use," with a score ranging from 0 to 10; "bladder," with a score ranging from 0 to 10; "bowel," with a score ranging from 0 to 10; "walking," with a score ranging from 0 to 15; "stairs," with a score ranging from 0 to 10." The mBI score ranges from 0 (fully dependent) to a maximum of 100 (fully dependent).

The FPS is a scale consisting of 11 faces; the faces are represented by an 8 cm × 8 cm black-and-white line drawing. Each face corresponds to a value from 0 (no pain) to 10 (worst possible pain).

The Nociception Coma Scale-revised (NCS-r) is an assessment tool developed and validated for measuring nociception and pain in patients with brain injury. The NCS consists of four subscales: motor response, verbal response, visual response and facial expression. Each of the subscales is scored from 0 to 3 points, where 3 points equals the maximum possible pain sign for each item. The NCS records the response to noxious stimuli.

The C-POT is a nonverbal pain behavior detection tool specifically for ICU patients. It consists of 4 behavioral indicators: facial expression, body movements, respirator adaptation (for intubated patients) or vocalizations (for non-intubated patients), and body tension. Each indicator has three response options (0, 1, or 2), accompanied by a brief description for correct scoring; the total ranges from 0 to 8 (higher scores indicate more intense pain). A total score greater than 3 indicates clinically relevant pain.

The Painad is a multidimensional scale of pain assessment, used for patients with marked cognitive impairment or uncooperative. The Painad consists of 5 basic parameters: (i) breathing, (ii) vocalization, (iii) facial expression, (iv) body language, and (v) consolation. A score ranging from 0 to 2 is given for each item, in ascending order of observed discomfort. Finally, the sum of the values obtained from each item is performed going to form a score ranging from 0 to 10. A score of 0 indicates no pain; 1 to 3 mild pain; 4 to 6 moderate pain; 7 to 10 severe pain.

The information inherent in the assessment of electrocortical activity, using the electroencephalogram (EEG), asking the patient to move the treated limb (or, if not possible, to imagine the movement). The presence of a cortical potential in motor area will be assessed by following the somatotopic organization, by reconstructing a brain map in amplitude;

Inclusion Criteria: Age between 18-75 years Picture of subacute sABI (20 days to 6 months after the acute event), of any etiology (traumatic, vascular, metabolic) Presence of spasticity in the affected limb as assessed by the Modified Ashwort Scale (MAS) ≥ 1+ Exclusion Criteria: recent treatment with botulinum toxin (within 3 months); ongoing treatment with systemic muscle relaxant drugs (baclofen, tizanidine, benzodiazepines); deep vein thrombosis; central/peripheral accesses ipsilateral to the limb(s) to be treated; oncological diseases; epilepsy; open skin lesions or local infections.

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