FOCAL DYSTONIA

Definition of focal dystonia

Focal dystonias identify alterations of the voluntary musculature typical of adulthood: spasms, contractions and stiffening of some muscle groups, and again the anomalous and abnormal postures, torsions and repetitive movements of some body regions, describe the pathological picture of dystonias. In particular, focal ones are characterized by rather prolonged movements over time, arrhythmic, up to degenerate causing real fixed and immobile positions. The affected subject involuntarily tends to worsen the condition by exercising an "antagonistic action at the level of the voluntary musculature, in an attempt to restore a correct position: in doing so, unfortunately, the condition sometimes worsens, deforming even more heavily the abnormal posture and making it sadly bizarre.

Classification

As we have seen, the onset of focal dystonias is emblematic of adulthood and, in most cases, the disease does not degenerate with the passage of time (unlike, for example, childhood dystonic forms), therefore it tends to remain circumscribed in the site primarily affected.
Among the best known focal dystonias, we remember:

Focal cervical dystonia

Blepharospasm

Focal laryngeal dystonia

Focal dystonia of the upper limb (eg scribe's cramp and musicians' dystonia)

Focal cervical dystonia

Focal cervical dystonia, also known as spasmodic torticollis, is the most frequent form of voluntary muscle alterations in adulthood. It is a full-fledged syndrome in which the affected subject presents evident involuntary spasms in the muscles of the neck: these contractions are responsible for the continuous tilting, bending and twisting of the head. Cervical pain is acute and penetrating, sometimes guilty of disability: in fact, among the possible serious complications, any degenerative forms affecting the medullary and cervical spine should not be underestimated.
The subjects most at risk are between the ages of 40 and 60, and it affects 10 subjects per million healthy individuals.
A correlation between focal cervical dystonias and some pathologies has been recorded in some affected subjects, including Wilson's disease and Parkinson's disease; sometimes, focal dystonias result from the administration of certain pharmacological specialties, such as neuroleptic substances (these drugs are involved in the creation of dyskinesias in general). Many patients affected by this focal dystonic form also have generalized tremor, considered a constitutive element of the disease itself.

Blepharospasm

After focal cervical dystonia, blepharospasm is the most common focal dystonia; the disease affects the face, particularly the upper part, and it is not uncommon for blepharospasm to be accompanied by other movement disorders. The kinetic disorder is characterized by muscle contractions and spasms that mainly involve the eyelids; sometimes, the disorder is so severe that it causes functional blindness. The patient is unable to control the movements caused by blepharospasm: the disorder begins with "excessive blinking " [www.distonia.it], and then degenerate into rapid, repeated and long-lasting spasms. The diagnosis must be precise and careful since, at first glance, blepharospasm could be mistakenly mistaken for tics.
Botulinum toxin therapy may prove useful in resolving blepharospasm.

Focal dystonia of the upper limb

These are mostly focal dystonias related to particular activities (eg playing, writing, etc.); in any case, there is no lack of focal dystonias of the non-action-specific upper limb, that is, not connected to secondary activities. wrist and, sometimes, of the forearm.
The contractions and spasms of the hand muscles, established during writing, can generate an incorrect way of holding the pen inevitably accompanied by a marked alteration of the handwriting, which is increasingly difficult to understand.
The use of hand braces (used in the past) in order to remedy the cramp of the scribe and modulate the posture of the hand during writing, has not shown many advantages in the symptomatological profile. Botulinum toxin represents the therapeutic option of excellence. , partially or totally resolving, to remedy this focal dystonia.
The dystonia of the upper limb also includes the dystonia of musicians, responsible for the progressive and inevitable shrinking of the fingers, which prevents playing musical instruments (eg piano); once again, the infiltration of botulinum toxin in the affected muscles from focal dystonia, it is particularly effective.