Encephalopathy

Generality

Encephalopathies are diseases characterized by an anatomo-physiological alteration of the brain. In other words, the brain of an individual affected by encephalopathy is modified in its structure and / or functions.

Encephalopathies may be due to various causes; symptoms, duration of illness, treatment and prognosis also depend on the triggers.

Thanks to an accurate diagnosis, it is possible to establish exactly the characteristics of the encephalopathy in place and the causes of onset. Only once these points have been clarified, is it possible to plan an adequate therapeutic course.

The prognosis is variable: if the encephalopathy is temporary, there is a real possibility of healing; if instead it is permanent, the patient can also be destined for death.

What is encephalopathy?

Encephalopathy is the term used to refer to a group of diseases that alter the structure and / or functions of the brain .

The various forms of encephalopathy can be permanent or temporary . If they are permanent, they last a lifetime; if instead they are temporary there is a possibility of recovery.

Some encephalopathies are congenital (that is, present since birth) and remain unchanged throughout existence, without deterioration; others are acquired (that is, they arise in the course of life) and may be subject to deterioration.

The various types of encephalopathy differ from each other in their triggers, symptoms, complications and prognosis.

Causes

The causes that can lead to the development of an encephalopathy are numerous and very varied.

The following table summarizes the triggers of the main known encephalopathies.

Type of encephalopathy	Causes
Chronic traumatic encephalopathy	It occurs as a result of multiple traumas or brain shocks. It is quite common in high-level contact sports, such as professional boxers (not surprisingly also known as boxing dementia).
Glycine encephalopathy	It is the result of a genetic condition, due to which there are excessive concentrations of glycine in the brain. Glycine is an ordinary amino acid.
Hashimoto encephalopathy	It is a rare consequence of an autoimmune disease that affects the thyroid gland. The disease in question is Hashimoto's thyroiditis .
Hepatic encephalopathy	It is the result of a seriously ill liver that no longer works properly. It is a classic complication of liver failure secondary to cirrhosis .
Diabetic encephalopathy	It is due to high blood glucose levels ( hyperglycemia ), typical of diabetes .
Hypertensive encephalopathy	It arises due to a state of persistent arterial hypertension .
Hypoxic encephalopathy	It arises when the brain does not receive the right amount of oxygen. The reasons for a lack of oxygen supply are related to respiratory or cardiovascular, temporary or permanent problems.
Lyme encephalopathy	It is one of the consequences of Lyme disease . Lyme disease is a bacterial infection transmitted by ticks. The bacterium responsible is Borrelia burgdorferi .
Static encephalopathy	The precise causes are unknown. Some researchers have put forward the hypothesis that it may be due to haemorrhage in the brain or infectious meningitis.
Metabolic toxic encephalopathy	It can be the consequence of some viral, bacterial and parasitic infections, or of coming into contact with certain toxic substances, such as cleaning products, pesticides, building materials, etc.
Transmissible spongiform encephalopathy	It is a consequence of prion diseases . Prions are proteins normally found in many animal species, including humans. If, for some reason, prions undergo a mutation, they can cause the following diseases: Kuru, Creutzfeldt-Jakob disease, fatal familial insomnia and Gerstmann-Str ä ussler-Scheinker syndrome .
Uremic encephalopathy	It is a possible consequence of renal failure .
Wernicke's encephalopathy	It arises due to a lack of vitamin B1 . Vitamin B1 deficiency is recorded in cases of severe alcoholism or malnutrition.
Mitochondrial encephalopathy	It is linked to metabolic diseases that cause various types of dysfunctions in the mitochondrial DNA .
Neonatal encephalopathy	This congenital type of encephalopathy arises during labor or delivery, and is due to a temporary lack / lack of oxygen in the blood directed to the brain of the unborn child.
Salmonella encephalopathy	It is caused by food poisoning contaminated with salmonella bacteria.
Encephalomyopathy	It is a combination of an encephalopathy and a myopathy. The causes include mitochondrial diseases and chronic hypophosphatemia (NB: hypophosphatemia is the medical term for low blood phosphorus levels).

Symptoms and Complications

Figure: head injuries due to contact sports are a cause of chronic traumatic encephalopathy. From the site: sodahead.com

The characteristic sign of all encephalopathies is the alteration of the mental state . Typical expressions of this alteration include: memory loss, personality changes, depression and inability to solve even simple problems of daily life.

Depending, then, on which are the triggering causes and which is the cerebral area involved, encephalopathies can provoke a long series of neurological disorders, such as:

Lethargy
Tremors
Myoclonus . These are involuntary tics of one or more muscles.
Asterissi . It consists of a sudden but temporary loss of muscle tone.
Difficulty speaking and swallowing
Attacks of epilepsy
Inability to concentrate
Nystagmus . It is a rapid and involuntary eye movement.
Muscle weakness
Loss of cognitive functions
Dementia
Cheyne-Stokes breath . It is a very particular disorder, due to which, cyclically, the patient's breathing slows down to a stop (apnea), and then recovers after a few seconds reaching a high depth (hyperpnea) and then becomes increasingly superficial until culminating in a new apnea phase.

These situations are all the more severe the more severe the changes that occur within the brain.

For example, in the case of hepatic encephalopathy, the symptomatology can evolve quite quickly and with more than evident consequences; in the case of chronic traumatic encephalopathy, however, the clinical course tends to be very slow, so that it is difficult to establish an early diagnosis.

WHEN TO REFER TO THE DOCTOR?

If you experience one or more of the above symptoms, you should contact your doctor immediately, without hesitation.

COMPLICATIONS

In general, the signs indicating a worsening of an encephalopathy are:

Marked worsening of symptoms already present
Serious state of confusion
Severe state of disorientation
Coma

Diagnosis

To diagnose an encephalopathy, both the physical examination, during which the doctor evaluates the symptoms and the signs in progress, and the examination of the clinical history, which provides a thorough investigation of the pathologies that have afflicted or afflict the disease, are very important. patient, on his lifestyle etc.

Therefore, at the end of these first two analyzes, it is usually necessary to subject the patient to more thorough checks: the intent is to pinpoint the causes and the precise brain areas involved.

BLOOD TESTS

Thanks to blood sampling and laboratory analysis, the doctor can determine whether the symptoms of encephalopathy are due to:

A viral, bacterial or parasitic infection
Inhalation or contact with toxic substances
Some prion disease.

Therefore, blood tests help to clarify the triggering causes.

LUMBAR PUNCTURE

The lumbar puncture consists in taking a sample of cerebrospinal fluid (or CSF ) and in its analysis in the laboratory. To remove the liquor, a needle is used that the doctor inserts between the lumbar vertebrae L3-L4 or L4-L5.

Like blood tests, the lumbar puncture provides help in identifying the triggering causes: in fact, if at the origin of encephalopathy there are infections, intoxications or prion diseases, these are readily identified.

TAC and NMR

Computerized axial tomography ( CT ) and magnetic resonance imaging ( MRI ) are two diagnostic imaging tests that, in the case of encephalopathy, help to recognize the affected brain areas.

Figure: Nuclear magnetic resonance of three individuals with Wernicke's encephalopathy. The white arrows indicate the signs of cerebral alteration. From the site: qjmed.oxfordjournals.org

ELECTROENCEPHALOGRAM

The electroencephalogram is an instrumental exam that allows to record the electrical activity of the brain and to detect any anomalies. It is a completely safe and painless diagnostic procedure.

Treatment

The treatment of an encephalopathy depends on the causes that triggered it.

This is why it is very important to study the disease and its symptoms thoroughly and with appropriate diagnostic tests.

If the causes are treatable, encephalopathy is treatable. In these cases, therapeutic remedies may consist of: various types of drugs (antibiotics, anticonvulsants, hypoglycemic drugs, substitute sugars, etc.), targeted rehabilitation therapies, surgical procedures for transplanting a sick organ and appropriate diet.

If, on the other hand, the causes are not treatable, encephalopathy results in: incurable, a possible reason for permanent brain damage and, in some situations (transmissible spongiform encephalopathy), reason for death.

SOME EXAMPLES

The following table summarizes some examples of possible treatments for some forms of encephalopathy.

In case of	Treatments
Hypoxic encephalopathy due to temporary and short-term respiratory problems.	Oxygen therapy, to increase the amount of circulating oxygen.
Hypoxic encephalopathy, due to a severe and prolonged respiratory incapacity.	Oxygen therapy Respiratory rehabilitation Respiratory physiotherapy Physiotherapy and rehabilitation serve, respectively, to restore (at least in part) breathing abilities and improve tolerance to efforts.
Hepatic encephalopathy	Oral lactulose Low protein diet rich in vegetables Antibiotics Lactulose, a low-protein diet and antibiotics are used to reduce the amount of ammonia in the blood ( ammoniaemia ). Lactulose hinders the growth of ammonia-producing bacteria and lowers the colonic pH (which is why the conversion of ammonia into a less dangerous substance, ie the ammonium ion, is favored). The low-protein diet obviously reduces the introduction of nitrogen compounds, hence also the production of ammonia. Finally, antibiotics kill ammonia-producing bacteria residing in the colon.
Uremic encephalopathy	Correction of the causes that cause kidney disease Dialysis Kidney transplant Kidney transplantation is the ultimate solution to cases of severe kidney failure.
Diabetic encephalopathy	Glucose administration Insulin administration Glucose is used to resolve any excessive blood sugar levels (severe hypoglycemia), which are very dangerous. Insulin, on the other hand, is used to control the opposite state, ie the conditions of hyperglycemia.
Hypertensive encephalopathy	Hypotensive, to reduce high blood pressure.

Encephalopathies that permanently alter the brain structure and / or that can lead to death are treatable only from a symptomatological point of view. In fact, in such situations, alleviating and managing symptoms is the only form of treatment that can be implemented.

Prognosis

The prognosis depends on the type of encephalopathy in place and its level of severity.

For some encephalopathies, such as transmissible spongiforms, the prognosis is always negative, since the brain damage is permanent and the patient is destined sooner or later to death.

For treatable encephalopathies, on the other hand, the prognosis can also be positive (or, if preferred, not negative), since there is a possibility of recovery or, at least, a partial restoration of normal brain function.

Warning: according to the National Institute of Neurological Disorders and Stroke (a US institution that deals with diseases of the brain and central nervous system), transmissible spongiform encephalopathies can lead to the death of the affected person even within 3-12 months.

Prevention

Unlike congenital encephalopathies, some acquired encephalopathies can be prevented.

In fact, if you adopt a healthy lifestyle and without excesses (so just doses of alcohol and proper diet), and if you avoid exposure to certain toxic substances, you can reduce the risk of getting sick of various forms of encephalopathy.