Writer’s cramp is a selective violation of the motor function of the leading hand, manifested when writing. It is characterized by discomfort, tonic spasm, trembling, weakness, pain, forcing the patient to stop the action. The diagnosis is made according to clinical data, the results of the study of neurological status, electroneuromyography, cerebral MRI. Treatment includes pharmacotherapy (muscle relaxants, benzodiazepines, adrenoblockers), kinesiotherapy, writing training. Injection therapy with botulinum toxin is possible.
General information
The term “writer’s cramp” quite succinctly characterizes the dyskinesia of the hand, which affects the writing process in isolation. In neurology, there are a number of synonyms for this syndrome: graphospasm, writing dysgraphy, writing cramp. Writer’s cramp refers to the focal dystonia of the brush, often associated with the peculiarities of professional activity that require rapid writing of a large amount of text. Other forms of selective motor disorders of the hand are observed when working on the keyboard (pianists, typesetters), playing a stringed musical instrument (violinists, harpists, guitarists). Studies conducted in European countries have shown that writer’s cramp occurs with a frequency of 14 cases per 1 million population. Pathology is prevalent mainly among middle-aged people, women and men get sick with the same frequency.
Causes
Professional graphospasm is an independent disease, the causes of which are not precisely established. Secondary writer’s cramp is a neurological syndrome that occurs in pathology of the central or peripheral nervous system. Accordingly , there are 2 etiological variants:
- Primary — occurs in the absence of a causal neurological defect. Refers to professional neuroses. The main etiological factor is daily monotonous writing, the provoking trigger is psycho—emotional tension. Persons with the following character traits are prone to developing the disease: irritability, excessive emotionality, self-esteem, suspiciousness, anxiety. Primary writer’s cramp accompanies a number of mental disorders (Briquet syndrome). Changes in the musculoskeletal system can contribute to the occurrence of dysgraphy: scoliosis of the thoracic spine, muscular hypotrophy of the shoulder girdle, the presence of an additional rib.
- Secondary — appears as a result of a disorder of the nervous regulation of muscle tone against the background of damage to the central nervous system, peripheral nerves. Symptomatic writer’s cramp along with hyperkinesis develops due to dysfunction of the extrapyramidal system, often acts as a manifest symptom of torsion dystonia, observed in Gallervorden-Spatz disease. Graphospasm can cause damage to the nerves of the hand with peripheral neuritis, cervical radiculitis, plexitis, secondary compression of nerve trunks with myositis. Dyskinesia of the hand in these cases is caused by dysfunction of the ulnar and/or median nerve.
Pathogenesis
The mechanism of development of the secondary variant of writing dysgraphy is clear. With a peripheral lesion, nerve irritation causes an increase in nerve impulses, causing spasm of the hand muscles, dysfunction of the nerve trunk fibers leads to muscle weakness. Pathological changes are provoked by the load of muscles during the writing of the text. Writer’s cramp as part of extrapyramidal syndrome is formed due to dysfunction of extrapyramidal structures of the premotor cortex, basal nuclei, which have a regulating effect on muscle tone, motor acts.
The pathogenesis of the primary variant of dysgraphy is under study. They assume the presence of isolated functional changes of the central nervous system, affecting exclusively the act of writing a text by hand. Since the connection of the disease with emotional overstrain has been noted, many authors consider graphospasm to be a separate form of neurosis, and consider the dysfunction of the limbic-reticular complex as the main pathogenetic aspect. Some researchers suggest that the pathology is a selective apraxia (disorder of motor skill) of writing associated with dysfunction of the dominant hemisphere.
Classification
The name of the disease “writer’s cramp” characterizes the most common spastic form. Individual cases of pathology have different features of symptoms, in connection with which the following classification of clinical forms of writing dyskinesia was proposed:
- Convulsive — accompanied by an increase in tone (spasm) of the small muscles of the hand. There is a feeling of awkwardness and heaviness in the hand.
- Paretic — manifested by a sudden sharp weakness in the arm. When writing, the pen literally begins to fall out of the patient’s hand.
- Shaky — the letter provokes intense shaking of the hand, making it impossible to continue the work.
- Neural — characterized by sudden muscle pain spreading to the forearm, shoulder. Painful sensations are described by patients as “breaking”, “pulling”.
Symptoms
A distinctive feature is the pronounced phasing of the development of disorders. The disease debuts with subclinical changes in handwriting, often ignored by the patient. Then there are episodic difficulties in writing that arise in certain conditions (the need to write quickly, strong emotions, physical overstrain). Over time, persistent changes in individual handwriting details develop, the patient begins to write more slowly, the first complaints appear. The spasm, weakness, tremor, and pain that occur during writing force the patient to interrupt work. Trying to adapt to the difficulties that have arisen, the patient uses various compensatory techniques: a special position of the hand / fingers, corrective gestures (shaking the hand, pushing with the healthy hand), the selection of a special writing tool (thick pen, brush).
At the initial stage of the disease, these dyskinetic manifestations are strictly isolated, other types of movements (sewing, playing a musical instrument, typing on the keyboard) absolutely safe. At the stage of pronounced clinical manifestations, the patient loses the ability to control dyskinesia by volitional effort, the compensatory strategies used by him stop working. Violations extend to motor acts of a domestic nature: stabbing food with a fork, typing on a mobile phone keyboard, buttoning buttons. There is a dependence of the severity of dyskinesia on the posture (it is easier to write standing), external circumstances. Extraneous observation, overwork, stressful situation aggravate dysgraphy, rest, calm benevolent mood — reduce its manifestations.
Complications
The progression of symptoms significantly complicates the professional activity of the patient. Work requires more concentration, time, and effort. As a result, there is chronic fatigue, low mood background. The usual performance of professional duties becomes a stressful situation for the patient, which aggravates the course of the disease. In the absence of adequate treatment, the disease continues to progress, spreads to everyday skills, there is a need to part with the previous job, to register a disability. Such events can enhance emotional experiences, provoke the development of neurotic disorders: depression, hypochondriac neurosis, anxiety-phobic disorder.
Diagnostics
Identification of a writer’s cramp does not cause much difficulty, it is enough to offer the patient to write a text on paper. In the process of writing, typical phenomena are determined: incorrect position of the hand and fingers; tonic tension, tremor, loss of the handle, stops due to the appearance of pain; compensatory actions (shaking, pushing, massaging the brush). The list of diagnostic studies includes:
- Anamnesis collection. Allows you to identify the stages of disease development, the absence of remissions, the presence of concomitant diseases (including neurological, mental).
- Neurological examination. At the time of the attack, the tonic tension / weakness of the muscles involved in writing is determined. The long course of the disease is accompanied by a stable decrease in muscle strength to 4-4.5 points (on a 5-point scale). The detection of concomitant neurological deficit indicates the secondary nature of graphospasm.
- Consultation of a psychiatrist. It is necessary for the diagnosis of mental disorders, borderline character traits. It is carried out by the method of conversation, testing.
- Electroneuromyography. It reveals a disorder of the regulation of the tone of individual muscles of the dominant forearm. With the secondary nature of graphoparesis, signs of axonal degeneration, segmental demyelination, radiculoishemia, partial denervation are possible.
- Testing the letter. The time and quality of writing a standard text is evaluated. It is characterized by a decrease in time when writing in a standing position, an improvement in the legibility of handwriting when using a pen with a rubber ball on.
- MRI of the brain. It is used to exclude organic intracranial pathology (encephalitis, brain tumors), the syndrome of which may be a writing spasm.
Differential diagnosis is performed with muscle diseases (myotonia, myopathy), ulnar nerve damage, carpal tunnel syndrome, vertebrogenic pathology (radiculopathy, intervertebral hernia). Differentiation of primary and secondary dyskinesia is carried out. The peculiarity of the primary form is strictly selective, extending exclusively to movements related to writing, the lack of data for the presence of causal pathology during the EMNG, MRI.
Treatment
Treatment is a difficult task that requires regularity, time, and patient perseverance. Pharmacopreparations are ineffective, give side effects, are used only in complex treatment. Therapy is carried out by a neurologist, kinesiotherapist, rehabilitologist (physical therapy doctor). An integrated approach is applied, including:
- Medical treatment. The drugs of choice are muscle relaxants (tolperizone, baclofen), benzodiazepine derivatives (clonazepam), adrenoblockers (propranolol). The most effective combination therapy with drugs of all these groups.
- Kinesiotherapy. The set of exercises is selected individually, taking into account the remaining preserved movements. The motor strategy is subject to constant revision, correction based on the results obtained. In some cases, patients are recommended to change the stereotype of writing: learning to write with the second hand, using the keyboard.
- The use of orthosis. A special device that fixes the fingers and brush allows you to extend the duration of continuous writing up to an hour, relieve the patient from discomfort.
- Letter training. It is carried out carefully, gradually, at first in an alternative position (standing), on paper with markings (lines, cells), using a brush, felt-tip pen, which do not require significant muscle tension. Slowly, the patient begins to write dashes, circles, then letters, words.
- Botulinum toxin injections. They are considered a promising method of therapy. The limited use of the technique is due to the complex anatomy of the arm muscles, which does not allow to accurately determine the target muscles.
During the treatment period, the patient must observe the daily routine, avoid overwork, stressful situations. To strengthen the nervous system, a sufficient duration of sleep, walking in the fresh air is of great importance. Acupuncture, acupressure, physiotherapy have a weak effect on the course of the disease, are used as auxiliary methods.
Prognosis and prevention
Writer’s cramp is characterized by a steadily progressive course, periods of remission are extremely rare (according to literature data in about 5% of cases). Without treatment, the aggravation of motor disorders leads to permanent disability. Complex treatment rarely allows you to completely overcome the resulting dyskinesia, but it helps to stop the progression of the disease, reduce the severity of symptoms, and preserve the professional fitness of the patient. Prevention of primary graphospasm should be carried out from childhood and be aimed at the formation of positive qualities of character that allow a person to maintain a calm, friendly attitude in any situation that arises. Prevention of secondary forms includes measures to prevent various lesions of the nervous system.