Alien Hand: description and treatment of three cases Giorgio Mandalà - Valentina La Mantia

The first case of h.s.a. was described in 1908 by the German neurologist Kurt Goldstein.[1]
In 1972 Brion and Jedynak described the observation of 4 patients.[2] The discovery of mirror neurons in the 90s, and recent studies Marti-Fabregas 2000,[13] Terazzi 2010, [14 ]Kim 2011,[15] Hertza 2012, [16]Shereef 2013[17], have reaffirmed the importance of the ways of vision, (semantic understanding, action in context, verification of the action), as basic elements in the elicitation and regulation of the automatic and voluntary movement. Voluntary movement and action, therefore, arise from the interaction of internal drives or wills, with the need to move and interact with the surrounding space, in relation to the context and the approach to the object; whether it is an action carried out in an implicit pragmatic or explicit way.
The connections between the parietal areas (intraparietal lobule) and the premotric areas of the frontal lobe are therefore decisive.

Effective treatment is based on neurocognitive rehabilitation techniques such as mirror box therapy [26,27]. You get the false but vivid impression of looking at both hands. It is important that the position is congruent with the point of view and that there are no distractions. By placing the alien hand behind the mirror and the other at the front, and looking at the mirror from a right angle, one sees the reflex of the hand overlapping the perceived position of the other hand. It was as if the brain had unlearned the learned disorder. [28]
This explains how the AHS is often present in cases of lesions of the parietal cortex, especially the right one, in which an interruption is created between this and the other cortical areas.
This interruption prevents the efferent copy of the planned movement from reaching the posterior parietal lobe from the premotor areas. Failure to compare the copy, with the re-afferent somatosensory information from the motor periphery, does not create the sense of self-generated action, and causes in the subject the sensation that the movement was generated by a force external to itself.[18]

TREATMENT

A.H.S. is a disease often difficult to diagnose. There are therefore no standardized treatments supported by evidence of scientific evidence. Traditional treatments consist in engaging the hand in activities that do not interfere with the actions of the right hand (to hold or manipulate objects). Other proposed treatments:
-Biofeedback e.m.g. with alarm signals, which seems to reduce the holding time of an object by the alien hand.
-Learning of motor tasks oriented to the contact of the alien hand with specific objects in particularly poor environmental contexts.
-Use of orthosis or restraints for the alien hand and the occlusive bandage (questionable as a hand with motor capacity).
-Waiting for spontaneous recovery or reduction of the phenomenon that sometimes appears in isolated lesions in the course of a year or so. [25]

Materials and methods

Take in charge in rehabilitation unit of three clinical cases:
Clinical cases: 1
acute onset: 46 year old woman, entry diagnosis: post-anoxic coma due to cardio-circulatory arrest; rmn: widespread axonal damage. Physical examination at the admittance:
vigilant, uncooperative, disorientated in space, in time and in the person, global coordination deficit, postural passages with high level of assistance and tendency to retropulsion, motor aphasia, ideo-motor apraxia; phenomenon of the left alien limb with embodyment; in orthostastism:
altered trunk control and balance control, with a tendency to retropulsion, perceptual disturbance for the posterior space. In the rehabilitation of orthostatism, gait and walking, the patient was educated in a standing position to name the parts of her body.

When the brain is faced with a chaos of conflicting sensory input, no sensorial feedback, helpless copies of motor signals, and in M.B. finds discrepant visual feedback sent from the mirror box, then it resorts to negation.
As in Garbarini's study, lines and circles were correctly executed by R.G. with the right and normal right hand; the phenomenon of Embodyment manifested itself only if the examiner's hand was the sin and was placed in an egocentric position. [29,30]

Clinical cases: 2
Man of 69 years. Entry diagnosis: right hemiplegia and sin emiparesis, fluent aphasia, spatial emineglancy u.l. - TAC left parieto-temporore-insular hemorrhage and temp. Right, subdural hematoma parieto-occip.dx. Clinical issues: double hemiparesis (right> sin), sin spatial emineglect, sensory aphasia, mixed dysphagia, ideo-motor apraxia, sustained attention deficit and short-term memory and behavioral disorders.
During hospitalization there was an improvement in the clinical conditions of the patient and recruitment of the right half-body.

Appearance of: Acalculia, Disgrafia, Lack of use of the upper left limb in the performance of the ADL (despite the good motor recruitment), Spontaneous "grasping" type of spontaneous movements; Lack of recognition of the left upper limb as its own; Confabulations.
Through the rehabilitation process, Mr. there is. it has recovered the sense of belonging and the voluntary control of one's upper left limb.

Clinical cases: 3
A 71-year-old right-handed woman developed acute left hemiparesis and visual hallucinations. She also complained that her left hand uncontrollably scratched her and pulled at her hair. Past medical history was notable for chronic hypertension and diabetes. Clinical evaluation disclosed full orientation, left lower facial weakness, right gaze bias, left hemibody hypesthesia, and extensor posturing of the left limbs, with the left hand constantly clenched. Cranial CT scan indicated acute right parietal cortical infarct and extensive bilateral subcortical white matter ischemic changes.