Generality
Sclerosis is the name that doctors give to any process of hardening of an organ, or a considerable part of it, as a result of an increase in the connective-fibrous tissue at the expense of normal parenchymal tissue.
Different organs and tissues of the human body can be victims of a sclerosis process.
The most popular types of human sclerosis are: multiple sclerosis, amyotrophic lateral sclerosis (ALS), arteriosclerosis, atherosclerosis, otosclerosis and tuberous sclerosis.
What is Sclerosis
Sclerosis is the medical term that indicates a process of hardening of an organ, or a considerable part of it, due to the increase in "scar tissue" (connective-fibrous) and to the regression of normal parenchymal tissue.
In other words, when subjected to sclerosis, an organ or tissue sees its normal parenchymal component decrease and the connective-fibrous component increased.
Depending on the causes, the regression of the parenchyma may precede the increase of the connective-fibrous tissue or vice versa (ie the increase of the connective-fibrous component may precede the decrease of the normal parenchymal tissue).
SCLEROSIS, FIBROSIS AND CIRRHOSES: THE DIFFERENCES
Sclerosis, fibrosis and cirrhosis are three different processes, which however, for some similar characteristics, are often confused with each other.
With the term fibrosis, doctors mean an increase in the connective-fibrous tissue in an organ, or in a portion of it, without any reference to the behavior of the parenchyma.
By the term cirrhosis, instead, they mean an increase in the connective-fibrous component in an organ or part of it, associated with a decrease in parenchymal tissue and attempts to regenerate this same tissue.
MASSIVE SCLEROSIS
The term massive sclerosis refers to a generalized sclerotic process, which involves an organ in its entirety.
Often, the process of massive sclerosis involves a decrease in the volume of the organ, consequent not only to a reduction in the parenchymal component, but also to a scar-related contraction of the newly formed connective-fibrous tissue.
Types of Scleroderma
Different organs and tissues of the human body can be victims of a sclerosis process.
The most popular types of human sclerosis are:
- Multiple sclerosis;
- Amyotrophic lateral sclerosis;
- Arteriosclerosis and atherosclerosis;
- Tuberous sclerosis;
- The otosclerosis;
- The osteosclerosis;
- Progressive systemic sclerosis;
- Hippocampal sclerosis;
- Segmental and focal glomerulosclerosis;
- The genital lichen sclerosus .
MULTIPLE SCLEROSIS
Multiple sclerosis is a chronic and debilitating disease, which occurs due to the progressive sclerotic degradation of myelin belonging to the neurons of the central nervous system (NB: the central nervous system, or CNS, includes the brain and the spinal cord).
The symptoms of multiple sclerosis can be mild or severe. Clinical manifestations considered mild are, for example, the numbness of the limbs and tremors; on the contrary, examples of serious disorders are limb paralysis or loss of vision.
Despite the many studies conducted to date, the precise causes of multiple sclerosis remain a mystery. According to the most reliable hypotheses, the disease could be the result of a combination of immunological, environmental, genetic and infectious factors.
The lack of knowledge of the precise triggering causes represents one of the main reasons why multiple sclerosis is an incurable condition. Currently, in fact, the only treatments available to patients consist of symptomatic therapies, ie treatments whose only effect is to mitigate the severity of the symptoms.
AMYOTROPHIC LATERAL SCLEROSIS
Amyotrophic lateral sclerosis, also known as ALS, Gehrig's disease or motor neuron disease, is a degenerative disease of the central nervous system, which specifically affects motoneurons, ie nerve cells responsible for muscle control and muscle movement.
As a consequence of the motor neuron degeneration, the ALS sufferer gradually loses the ability to: walk, breathe, swallow, speak and hold objects.
ALS always has a dramatic course and a fatal outcome: the patient dies (usually due to severe respiratory insufficiency) after about 3-5 years from the onset of the disease and, in this period of time, is first forced to the chair to wheels (because paralyzed) and then to breathe through a support for mechanical ventilation.
The causes that trigger the degenerative process of the motor neurons - which is then a process of sclerosis - are unknown.
As long as the triggers of ALS remain unknown, the chances of developing a specific cure (and not just to alleviate symptoms) are practically nil.
ARTERIOSCLEROSIS AND ATEROSCLEROSIS
In medicine, the term arteriosclerosis identifies all those forms of hardening, thickening and loss of elasticity of the wall of the arteries, ie the blood vessels that carry blood from the heart to the periphery.
Atherosclerosis is the most known and widespread form of arteriosclerosis.
According to the most recent definitions, it is a degenerative disease of medium and large caliber arteries, characterized by the presence of atheromas on the inner wall of arterial vessels.
The atheromas are plaques of lipidic material (mostly cholesterol), protein and fibrous, which, in addition to obstructing the lumen of the arteries and preventing blood flow, can also become inflamed and fragmented. The fragmentation of an atheroma is responsible for the dispersion, in the bloodstream, of moving bodies, which can occlude small arteries located even very far from the site of origin of the same atheroma.
Progressive morbid condition, atherosclerosis represents an important risk factor for serious pathologies, such as: angina pectoris, myocardial infarction and stroke.
Various factors can contribute to the formation of atheromas on the wall of the arteries, some of which cannot be modified and others which can be modified.
Favorable factors that cannot be changed include advanced age, male sex, familiarity and race.
Among the modifiable favoring factors, on the other hand, there are: cigarette smoking, hypercholesterolemia, hypertension, obesity, a sedentary lifestyle and diabetes mellitus.
Arteriosclerosis is a subtle condition, as, very often, it remains silent until the worst consequences appear.
- Atherosclerosis
- Arteriolosclerosi
- Calcific sclerosis of Mönckeberg
TUBEROSIC SCLEROSIS
Tuberous sclerosis is a genetic disease characterized by the formation of hamartomas in different organs and tissues of the human body.
The result of a very intense cellular multiplication process, a hamartoma is an obvious cluster of cells, similar to a nodule or a tuber. Hamartomas are not tumors, but sometimes they could become tumors, assuming the characteristics of benign neoplasms comparable to fibroids and angiofibromas.
Tuberous sclerosis, with its hamartomas, mainly affects the brain, the skin, the kidneys, the heart and the lungs. Given the multiplicity of organs and tissues it can involve, it is one of the multisystem genetic diseases.
The genes, whose mutation is responsible for the appearance of tuberous sclerosis, are known as TSC1 (chromosome 9) and TSC2 (chromosome 19). According to various statistical surveys, the majority of patients with tuberous sclerosis (approximately 80%) would present a mutation of TSC2 and only a small part (approximately 20%) of a mutation of TSC1.
TSC1 and TSC2 mutations may arise spontaneously, during embryonic development, or may have a hereditary origin.
- Skin manifestations. They typically consist of depigmented spots on the body, areas of thickened skin, growth of layers of skin under or around the nails and spots tending to red on the face.
- Neurological manifestations. Hamartomas in the brain can determine: episodes of epilepsy, appearance of subependymal nodules or subependymal astrocytomas in giant cells and, finally, mental deficits in behavior and learning.
- Renal manifestations. They can be the result of the rupture of hamartomas located in the kidneys or the consequence of alterations of the renal anatomy.
In the first case, they generally consist of: hemorrhage, hematuria and abdominal pain; in the second case, they may consist of: horseshoe kidney, polycystic kidney, renal agenesis and double ureter.
- Cardiovascular manifestations. Due to hamartomas located on the walls of the cavities of the heart, they consist of arrhythmias and cardiac flow abnormalities.
In severe cases, hamartomas located in the heart may result in heart failure.
- Lung manifestations. They are mainly due to two conditions, whose specific name is: lymphangioleiomyomatosis (LAM) and micronodular multifocal hyperplasia.
LAM is responsible for cysts in the lungs, it mainly affects female patients and causes symptoms such as dyspnea, cough and spontaneous pneumothorax.
Micronodular multifocal hyperplasia is a cause of nodules in the lungs, equally affecting both sexes and is often asymptomatic.
otosclerosis
Otosclerosis is a pathology of the ear, characterized by a sclerotic process affecting the stirrup, one of the three ossicles of the middle ear (the other two being the hammer and the anvil).
The process of sclerosis that characterizes otosclerosis induces the formation, around the bracket, of an abnormal bone mass; this bone mass stiffens and blocks the movements of the stirrup itself, thus altering the transmission of sound waves entering the ear and directed towards the brain. An incorrect transmission of sound waves, along the chain of the three small bones of the middle ear, affects the hearing ability, and therefore the perception of sounds.
The presence of otosclerosis in an individual coincides with a gradual hearing loss. Failure to treat otosclerosis can lead to complete deafness.
The precise causes of otosclerosis are unknown. However, there is a fairly reliable hypothesis, which recognizes the reasons for the disease in the interaction between genetic and environmental factors.
Otosclerosis is usually a bilateral problem; unilateral otosclerosis is very rare.
Currently, the therapies available to patients consist in the use of external acoustic prostheses and in surgical practice aimed at removing / remodeling the bracket.
If the treatment is carried out in time, the prognosis is generally positive.
osteosclerosis
Osteosclerosis, or bone sclerosis, is a pathological process that causes abnormal hardening and an equally abnormal thickening of a bone.
In most cases, osteosclerosis is due to a condition of osteoarthritis, ossifying osteitis, reactive osteitis or osteoid osteoma.
A fair number of patients with osteosclerosis suffer from this disorder without recognizable reasons (idiopathic osteosclerosis).
Due to the sclerosis process, the affected bone is denser and more compact than normal. In fact, what happens in the case of osteosclerosis is opposite to what occurs in case of osteoporosis.
PROGRESSIVE SYSTEMIC SCLEROSIS
Progressive systemic sclerosis, better known as scleroderma, is a pathology of the skin, characterized by abnormal hardening and an equally abnormal thickening of the skin.
In most cases, scleroderma affects the skin of the arms and legs and the skin area around the mouth. More rarely, it also affects the capillaries, arterioles and internal organs heart, kidneys, intestines and lungs.
When progressive systemic sclerosis also involves internal organs, it can have very serious consequences, including the death of the patient.
Despite numerous studies on the subject, the precise causes of scleroderma are unknown. According to some researchers, the condition would be linked to some genetic factor.
Currently, there is still no cure for scleroderma, but only a symptomatic treatment that relieves disorders and improves the quality of life for patients.
HIPPOCAMPAL SCLEROSIS
Hippocampal sclerosis is a neurological condition characterized by a severe loss of nerve cells (or neurons) and a process of gliosis involving a specific section of the temporal lobe of the brain, known as the hippocampus.
Currently, the precise causes of hippocampal sclerosis are unclear. According to some theories, factors such as advanced age, vascular problems (hypertension and stroke in particular) and belonging to the lower socioeconomic classes are favoring the appearance of the condition.
The most characteristic consequence of hippocampal sclerosis is a form of epilepsy, known as temporal lobe epilepsy .
According to statistics, hippocampal sclerosis presents a remarkable mortality.
What is gliosis?
In medicine, the term gliosis indicates a pathological proliferation of glia cells.
GLOMERULOSCLEROSI SEGMENTARIA AND FOCALE
Segmental and focal glomerulosclerosis is a condition that alters the normal anatomy of the renal glomeruli and causes nephrotic syndrome .
Following the appearance of segmental and focal glomerulosclerosis, the renal glomeruli of the affected person present a connective-fibrous component superior to normal and a reduced healthy parenchymal component.
The precise causes of segmental and focal glomerulosclerosis are unknown. For reasons that are still unknown, the condition in question is more frequent in the male population.
The most important complication is renal failure.
The only therapies available to patients are symptomatic: their purpose is to alleviate the symptoms and avoid (or at least delay) the onset of renal failure.
Symptoms that characterize the presence of nephrotic syndrome:
- Presence of proteins in the urine, which become foamy;
- Reduction in the amount of protein in the blood;
- Appearance of generalized swelling (edema), initially at the level of the face, then extended to the rest of the body (feet, ankles, abdomen, etc.);
- Presence of hyperlipidemia, with increase in total cholesterol or triglyceridemia;
- Hypercoagulability of blood, with consequent increase in the risk of thrombo-embolism.
LICHEN GENITAL SCLEROSUS
Lichen sclerosus genitale, or more simply lichen sclerosus, is an inflammatory condition of a sclerotic nature, which affects the skin and mucous membranes.
Due to causes still unknown, lichen sclerosus can affect any district of the human body; however, it usually affects the genital areas (both when the patient is a man and when he is a woman).
At the level of the female genitalia, lichen sclerosus is responsible for: itching, burning, dyspareunia and dryness of the vaginal and perianal mucosa.
At the level of the male genitalia, on the other hand, it is a potential cause of: shiny white-brownish patches associated with excoriation, microlesions, pruritus, penodynia, pain, dyspareunia, urethritis, urethral stricture and tight phimosis.
For most affected people, genital lichen sclerosus is a long-term condition.
Currently, there are no specific treatments, only symptomatic treatments.
The main symptomatic treatment of genital lichen sclerosus consists of topical application of corticosteroids.
Particularly serious episodes of lichen sclerosus can determine processes of sclerosis that make surgical practice necessary.
