Action Observation Theraphy in Severe Acquired Brain Injury.

Action Observation Therapy (AOT) is a rehabilitation technique, used for several years, aimed at the recovery of motor function in patients with neurological and orthopedic conditions.

The essential element of this approach is the patient's observation and subsequent mime of a sequence of daily actions, aimed at achieving a goal. This task is proposed repeatedly during a single rehabilitation session and repeated for a set number of sessions. The recovery of the presented motor patterns has, as its ultimate goal, the improvement of autonomy in activities of daily living (ADLs).

The neurophysiological mechanism underlying motor cortical recovery is related to the activation of mirror neuron circuits and includes mechanisms of neuronal plasticity. In fact, it is well known how motor brain areas injured by a pathological process are able to activate during tasks of imagining or observing movements, with a correspondence between the type of movement observed and the specific motor cortical region involved in the given action. Activation of the brain areas in charge of movement, in addition to keeping the uninjured networks functioning, stimulates the injured ones by promoting, by mechanisms of neuronal plasticity, a reorganization of the primary motor cortex. The physiological basis for motor learning would thus be established, the cortical reorganization being decisive for the formation of a motor memory of the observed gesture and allowing the reacquisition, even partial, of the function of the injured motor cortex. Finally, motor cortical stimulation has a function in preventing dysfunctional cortical reorganization that intervenes after inactivity or disuse. As revealed by systematic review studies on the subject, the protocols used are very heterogeneous in terms of the type of patients to whom they were offered, the type and number of actions shown during treatments, their duration, and the rating scales used.

However, in the context of patients with neurological diseases, studies have mainly been conducted on patients with outcomes of stroke, infant cerebral palsy, and Parkinson's disease. Very few data are available in the literature on the possible efficacy of AOT in patients with severe acquired brain injury (sABI).

The advantage of AOT is that it represents a method that is noninvasive, requires readily available and low-cost instrumentation, is undemanding in terms of time and resources, and for whose application there are no known adverse reactions.

In light of the above, the purpose of the study is to evaluate the application and effectiveness of rehabilitative treatment with AOT in patients with sABI of different etiology.

The research hypotheses consist of: (i) improvement of motor function assessed by clinical and functional scales (ii) improvement of cerebral cortical activation, particularly in terms of improvement of basic rhythmic frequencies and connectivity, assessed by EEG method, after rehabilitative treatment with AOT in patients with outcomes of sABI.

Eligibility Criteria:
Inclusion Criteria:

* Age between 18 and 80 years;
* Having presented with a documented coma state with Glasgow Coma Scale (GCS) values ≤ 8, for at least 24 consecutive hours;
* Minimal Consciousness State (MCS) or emergence from Minimal Consciousness State (eMCS)
* Presence of muscle activity in at least one upper limb,
* Traumatic, cerebrovascular, anoxic, infectious, metabolic etiology;
* Time since acute event: 1 - 4 months;
* Unilateral or bilateral clinical involvement;

Exclusion Criteria:

* Patients in a comatose or vegetative state (VS)
* premorbid history of psychiatric or neurological conditions;
* concomitant presence of sepsis, coma, or other medical conditions that severely alter the patient's health status;
* Changes in therapy, during the study period, that may affect vigilance status (antiepileptic drugs, antidepressants, etc.) or spasticity;
* Presence of upper limb fractures;
* Level of spasticity Ashworth modified≥ 3