Arachnodactyly is a congenital deformity of the fingers of the hand, manifested by their elongation, thinning and characteristic curvature. It is a symptom of some hereditary diseases, usually combined with elongation of tubular bones, other skeletal deformities, changes in the eyes and cardiovascular system. The diagnosis is made on the basis of local examination data. To determine the underlying pathology, a comprehensive examination is carried out, including a general examination, the study of genealogical data, a number of analyses and hardware studies. Treatment of aranchodactyly is not required, when other disorders are detected, symptomatic therapy is prescribed, reconstructive operations are performed.
Q87.4 Marfan Syndrome
Arachnodactyly (translated from Latin “spider fingers”) is a syndrome that is observed in some hereditary diseases associated with metabolic disorders. The first description of this pathology dates back to 1876. 20 years later, the French pediatrician Marfan published studies in which he described similar disorders in a five-year-old girl. The disease became known as “Marfan syndrome”. Subsequently, it was found that arachnodactyly is a hereditary pathology of connective tissue and can be detected not only in this syndrome, but also in some other rare hereditary diseases.
Causes of arachnodactyly
Most often, a characteristic change in the shape of the fingers is observed in Marfan syndrome, along with other changes in the skeleton is included in the clinical picture of homocystinuria. There are also a number of marfan-like syndromes – hereditary diseases, which are also accompanied by arachnodactyly, but differ in manifestations from the internal organs. The pathologies combined with arachnodactyly include:
- dilation syndrome and aortic dissection;
- ectopic lens syndrome.
It is assumed that the cause of the development of syndromes accompanied by arachnodactyly is a violation of protein synthesis caused by similar genetic mutations. With Marfan syndrome, an autosomal dominant type of inheritance is noted, with homocystinuria – autosomal recessive. In addition, arachnodactyly may be the result of spontaneous genetic mutations.
Symptoms of arachnodactyly
Pathology is manifested by characteristic changes in the shape and size of the brush. The fingers of patients with arachnodactyly are disproportionately thin compared to the palm, excessively long, curved, with a typical deformation in the area of the interphalangeal joints. All of these manifestations give the patient’s hands a peculiar appearance, because of which the deformation was called “spider fingers”.
Sometimes, along with an unusual appearance, excessive mobility of the fingers is detected – one or more of them may deviate 180 ° to the back side. Usually the elongation of the fingers is accompanied by other pathological changes on the part of the skeleton, eyes and internal organs. The nature of changes in arachnodactyly is determined by the type of hereditary disease.
The severity of various pathological changes in arachnodactyly can vary significantly – from mild, with the absence of a number or most of the signs, to severe, with impaired ability to self-care and an unfavorable prognosis for life:
- All tubular bones are elongated, arms and legs are disproportionately thin and long. Due to the weakness of the ligamentous apparatus, excessive joint mobility often occurs. Pronounced flat feet are observed.
- The head is enlarged in size, the skull is elongated, the back of the head is flattened, the forehead is high, with pronounced frontal bumps. The lower jaw is protruding anteriorly or, conversely, weakly pronounced and looks underdeveloped.
- The muscles are atrophied and almost invisible under the skin, the fat layer is almost not pronounced.
- There is a curvature of the spine, a flat pelvis, a keeled deformation of the sternum or a funnel-shaped chest.
- The sclera are bluish, myopia, dislocation of the lens is noted.
- An aortic aneurysm and various heart defects are often diagnosed.
Patients also have pronounced arachnodactyly, elongation of tubular bones, deformity of the chest, pelvis and spine, disorders of the cardiovascular system and the eyes. Along with this , the following symptoms are detected:
- Osteoporosis. Increased bone fragility is accompanied by frequent fractures with minimal traumatic effects.
- Disorders of neuropsychic activity. IQ is reduced to 32-72 units (normally 85-115 units), poor performance, problems when switching attention, uncritical attitude to their capabilities, simplified speech, dyslalia, weakening of facial expressions.
Diagnostics of arachnodactyly
The diagnosis of a disease accompanied by arachnodactyly is made on the basis of an external examination and a number of instrumental studies. Assessment of the state of the musculoskeletal system is performed during the examination of the orthopedist. If necessary, a patient with arachnodactyly is referred for consultations to a neurologist, cardiologist and ophthalmologist. Basic diagnostics include:
- Radiography and tomography. Patients are X-rayed of the chest, pelvis and spine. To clarify the nature of pathological changes according to the indications, CT and MRI are performed.
- Sonography. In case of suspected violations of the cardiovascular system, a cardiologist may prescribe ultrasound of the heart and blood vessels, duplex scanning of blood vessels and a number of other studies.
- Neurological examination. The neurologist conducts special tests, can refer the patient to MRI of the brain, CT of the spine, electroencephalography, rheoencephalography, etc.
- Ophthalmological examination. An ophthalmologist performs an examination of the structures of the eye, if there are indications, measures intraocular pressure, prescribes optical, ultrasound and other examinations.
During the examination, differential diagnosis of arachnodactyly in homocystinuria and Marfan syndrome is carried out:
- Homocystinuria is more often diagnosed in blondes with light skin and blue eyes, seizures and dementia are characteristic. With Marfan syndrome, the hair is dark, intelligence is preserved, there is no convulsive syndrome.
- With homocystinuria, there is a subluxation of the lenses downwards, the lesion of the eyes is progressive, secondary glaucoma develops over time. In patients with Marfan syndrome, subluxation of the lenses upward is detected, myopia proceeds more favorably, secondary glaucoma is not detected.
- With homocystinuria, osteoporosis is observed, less pronounced flat feet and slight excessive joint mobility, damage to medium-caliber arteries, with Marfan syndrome there is no osteoporosis, flat feet and excessive joint mobility are more pronounced, pathology of the heart and large vessels prevails.
- With homocystinuria in urine and biochemical blood analysis, an increased content of methionine and a decrease in cystine levels are determined, homocysteine is detected, with Marfan syndrome, these changes are absent.
Treatment of arachnodactyly
Treatment is symptomatic. Patients with arachnodactyly, regardless of the cause of its occurrence, are under constant dispensary supervision, according to indications, they are sent to physical therapy, massage and spa treatment. With a decrease in vision, eyeglass correction is performed.
The purpose of drug treatment of diseases accompanied by arachnodactyly is to improve the general condition, reduce the severity of symptoms, and prevent the development of dangerous complications. The therapy plan may include:
- Collagen normalizing agents. All patients are recommended medications to improve the structure of connective tissue.
- Cardiovascular drugs. According to the indications, calcium channel blockers, adrenoblockers, ACE inhibitors are prescribed.
- Metabolic and vitamin remedies. Multivitamin complexes, drugs to improve metabolism, and nootropics are used to improve metabolic processes.
- Preventive medications. Anticoagulants are indicated to prevent the formation of blood clots, and antibiotics are indicated for the prevention of infectious endocarditis.
In case of pathology that threatens the life of a patient with arachnodactyly and significantly worsens his condition, various operations are performed:
- On the heart and blood vessels. Patients with Marfan syndrome may require prosthetics of heart valves, prosthetics of the aorta.
- On the musculoskeletal system. With keel-shaped and funnel-shaped deformities, reconstruction of the chest wall is shown. In severe arthrosis, joint replacement is performed. With severe scoliosis, spinal fractures on the background of osteoporosis, stabilization, fixation of fragments is performed.
- On the organ of vision. If necessary, glaucoma elimination, lens replacement, laser interventions to eliminate myopia are performed.
Prognosis and prevention
The prognosis is determined by the severity of cardiovascular pathology, changes in the musculoskeletal system and eyes. Timely initiation of therapy, early surgical correction of the resulting disorders can increase the duration and improve the quality of life of patients. Patients with this disease should be under constant medical supervision. People who have relatives with arachnodactyly are recommended medical and genetic counseling before the birth of a child.