Malignant neuroleptic syndrome

Malignant neuroleptic syndrome (CNS) is an acute life-threatening condition, most often a complication of neuroleptic therapy. It can also occur when taking other drugs that block dopamine receptors. Despite the achievements of modern medicine, the mortality from malignant neuroleptic syndrome and is currently 5-20%. Even the timely placement of a patient in a specialized intensive care unit does not always guarantee a favorable outcome of this condition, if the existing violations increase and no corrections are given.

How NSN is developing

Thin biochemical mechanisms of the brain and the entire body continue to be studied. According to modern views, the malignant neuroleptic syndrome is mainly of central origin. This means that the main disorders occur in the brain, or rather, in its subcortical structures. But the importance of the effect of drugs on skeletal muscles. This leads to the destruction of muscle cells (rhabdomyolysis) and the binding of peripheral dopamine receptors.

Under the action of neuroleptics and some other drugs, there is a massive blockade of central dopamine receptors in the hypothalamus and basal nuclei. This causes a metabolic disorder, persistent hyperthermia (elevated body temperature), and severe motor disorders by extrapyramidal type, the most important of which is muscle rigidity.

Disturbance of dopamine metabolism changes the activity of the serotonergic system in the brain, later cascade reactions develop with violation of the work of other neurotransmitters. As a result, the sympathetic nervous system is disinhibited, vegetative disorders appear and grow, the work of the heart is disrupted.

Central disturbance of water and mineral metabolism leads to a change in the permeability of the blood-brain barrier. Because of this, various toxic substances begin to flow to the nerve cells through the walls of the vessels, swelling and subsequent cerebral edema occur. All this leads to mental disorders and various violations of the level of consciousness. In the blood plasma, the acid-base balance shifts and the concentration of the basic electrolytes changes.

In unfavorable course, malignant neuroleptic syndrome is often complicated by cerebral edema, pulmonary edema, cardiovascular insufficiency, acute disruption of kidney and liver function. All these are possible causes of death.

What can lead to NNS

Malignant neuroleptic syndrome refers to iatrogenic psychoneurosomatic conditions, then it occurs only in response to ongoing therapy and is directly related to a particular medication.

The main drugs that can cause NSA:

• typical (classical) and atypical antipsychotics of different groups;
• metoclopramide or cerucal (antiemetic);
• reserpine (a drug used to treat arterial hypertension and vegetative disorders of various origins);
• tetrabenazine (a drug for the treatment of chorea, hemiballism, nervous tics, Gilles de la Tourette's syndrome, late dyskinesias);
• antidepressants, especially those related to the tricyclic and SSRI group;
• lithium preparations.

ZNS when taking antidepressants is rare, the violation of dopamine metabolism is secondary to the change in the work of the serotonergic system. The effect of lithium drugs is due to the neurotoxic effect that can occur if the therapeutic concentration is exceeded, a long uncontrolled admission and against a background of impaired renal function.

Malignant neuroleptic syndrome can occur with a sharp cancellation of correctors and antiparkinsonian drugs, so sometimes it is observed after a sharp irrational therapy change in patients with Parkinson's disease or syndrome.

Predispose to the development of the NSA is the existing organic cerebral insufficiency, dehydration, physical exhaustion, fasting, postpartum period, anemia. Even slight damage to the brain in the past can affect the tolerability of neuroleptic therapy. Therefore, in the risk group for the development of complications are people with perinatal damage to the nervous system, who have undergone craniocerebral trauma and neuroinfections, suffering from alcoholism, degenerative and demyelinating diseases of the brain.

Main features

Malignant neuroleptic syndrome includes a set of characteristic disorders. Some of them are mandatory and are included in the diagnostic criteria, others do not always arise and therefore are considered optional (optional). Mandatory symptoms include muscle rigidity, fever, autonomic disorders and mental disorders.

Rigidity is an increase in muscle tone, which leads to their tightening and limiting active and passive movements. In the flexor, the tone increases more than in their antagonists. Therefore, a person has a forced position of the body and limbs. Sometimes the rigidity is so pronounced that it is almost impossible to bend the arm or leg to the patient with the ZNS. This is called the lead tube symptom. Stiffness is usually the first sign of neurolepsy, it quickly builds up and combines with pronounced and persistent hyperthermia.

The increase in muscle tone occurs on an extrapyramidal type, so the symptom of the gear wheel is revealed (stepwise movements when flexion occurs with small jerks with pauses between them). Often, other extrapyramidal signs are identified. This can be tremor (trembling), akathisia (restlessness), dystonia, oculogic crises (eyeballs up), clonus of the feet, increased tendon reflexes, myoclonus. Violation of swallowing, pronunciation of sounds, masculinity of the face also appears.

Vegetative disorders are manifested in the instability of blood pressure, heart rhythm disturbance, tachycardia (rapid heart rate), sweating, salivation, characteristic skin fatigue with a simultaneous decrease in its elasticity, impaired urination. All this is supplemented by signs of dehydration.

Mental disorders increase with the progression of violations of water-electrolyte and neurotransmitter metabolism. There may be anxiety, psychomotor agitation, confusion, delirium, onyroid, amenia, catatonia, sopor and coma. It is important to assess the change in the patient's condition in a timely manner and not to overlook the transformation of psychosis as a result of increasing changes in the brain. This will reveal the malignant neuroleptic syndrome in the early stages and cancel the medications that are obtained.

When complications develop, symptoms of polyorganic insufficiency, pulmonary edema appear, and with the edema of the brain, various neurological disorders increase.

Diagnostics

A characteristic feature of the NSA is an increase in the blood of creatine phosphokinase.

Identification of the NSA is based on an analysis of the patient's symptoms, and laboratory diagnosis helps assess the severity of the disorders and monitor the effectiveness of the therapy.

In blood plasma, practically all patients with CNS have an increase in creatinine phosphokinase (CK), which is due to the destruction of muscle cells. But this is not an absolute confirmation of the diagnosis and can not serve as a screening test. After all, if a person already had at least mild neurolepsy, then the increase in CFC in him, most likely, will occur even with the common cold and the attachment of any infectious disease.

The analysis usually reveals an increase in the level of leukocytes and ESR, metabolic acidosis and a violation of electrolyte balance, protinuria and azotemia due to obstruction of the renal tubules by the products of the decomposition of muscle cells.

Instrumental diagnosis in the NSA is not required, it will not provide any clinically relevant information. Only in disputed cases, to avoid brain damage, an MRI or CT scan may be required.

Principles of treatment

The severity of the condition and the potential threat to life are an indication for the urgent transfer of the patient to a specialized Department of resuscitation and intensive care, if such a department is in a medical institution. If this is not possible, the patient is placed under intensified round-the-clock supervision of personnel, his condition is regularly monitored by the doctor. At the same time, measures are being taken to arrange transportation of the patient to the intensive care unit of another hospital. It is often necessary to consult a neurologist and a therapist.

The appearance of signs of a malignant neuroleptic syndrome requires the immediate withdrawal of the neuroleptic or another drug that caused this condition. Difficulties arise when depot forms of neuroleptic drugs are used. In this case, as early as possible, correctors are prescribed, which reduce the severity of extrapyramidal and vegetative disorders. These funds are required and when using neuroleptics short-acting, but the duration of their reception in this case will be less.

Improve the patient's condition, reduce tonic tension and relieve agitation with sedatives (tranquilizers). They also allow you to monitor the behavior of the patient in the development of disorders of consciousness and psychotic disorders.

Symptomatic therapy ZNS includes the replacement of fluid deficiency, improve blood rheology, correction of acid-base equilibrium and electrolyte imbalance, therapy of emerging complications. It is important to monitor the state of the blood coagulation system, to prevent the disseminated intravascular coagulation (DVS) syndrome and deep thromboses. For this, subcutaneous injections of small doses of heparin are often used.

To control diuresis, establish a urinary catheter. Medications are administered intravenously, for which the central or peripheral veins are usually catheterized. With the development of respiratory failure, a decision may be made to intubate the trachea.

It is not necessary to be frightened of the volume of the injected liquid, it is required for detoxification, prevention of renal failure, elimination of dehydration and normalization of blood fluidity. And nutrition of patients at first can be carried out parenterally, for which special solutions are used. Subsequently, they switch to probe nutrition, and after the restoration of swallowing, they return the person to a natural way of eating.

One of the rather effective non-pharmacological methods of treating malignant neuroleptic syndrome is electroconvulsive therapy (ECT). Modern methods suggest a gentle way of carrying out this procedure, with the use of muscle relaxants, sedation or even the application of short-term anesthesia.

Malignant neuroleptic syndrome is a formidable complication, requiring an early start of intensive treatment. The earlier the diagnosis is established and the neuroleptic is canceled, the better the prognosis for the patient. Sometimes even after the relief of this syndrome, the person who has transferred him has a neurological disorder for a long time, which will require continuation of the therapy recommended by the doctor.