Stereotactic thalamotomy is a type of surgery that involves the destruction of certain areas of the thalamus. The impact on the brain areas can be carried out mechanically, radio frequency, ultrasonic or electrothermal way.

Features of the thalamotomy

This type of surgical intervention does not oblige the surgeon to put the patient under general anesthesia. The brain has no pain receptors, so working with it does not bring discomfort to the patient. To destroy the nuclei of the thalamus, the surgeon uses local anesthesia: thanks to this, the patient is in a conscious state, can contact the surgeon and other medical personnel.

The greatest role in the effectiveness of the procedure is played by the qualitative construction of intracerebral coordination structures, the accuracy of which depends on the site of action, as well as adherence to all algorithms for the operation. Computed tomography and radiological control help the surgeon to clearly localize and correctly direct the beam exposure. Due to the fact that the patient is in a clear mind, his words and physiological reactions help the neurosurgeon determine the correctness of the impact on the thalamus and other therapeutic measures. The thalamus undergoes destruction in two main stages (basic and trial). The patient's head is fixed in a stereotoxic frame, due to which it is immobilized. The diameter of the hole for trepanation is 1.0-1.5 cm: this feature eliminates the risk of complexes due to aesthetic defects on the skin after the operation. After the neurosurgeon accurately hits the desired area, electrodes are used, the temperature at the tips of which reaches 75 degrees Celsius.

Efficiency

The thalamotomy acts on the foci that cause pathological symptoms. As a rule, after destruction, the symptoms disappear already on the operating table. With dyskinesia, the symptoms disappear smoothly, within a few months. Due to its accuracy, focus on pathological impulses, safety and minimally invasiveness, thalamotomy is considered an extremely effective way to treat parkinsonism and other nervous diseases.

Pallidotomy is a surgical intervention that involves the destruction of individual zones of the pale ball on one side. Unlike thalamotomy, pallidotomy is performed in cases where unilateral stiffness and slowness prevail in the patient. The indication for performing unilateral pallidotomy is the presence of pronounced medicinal dyskinesias while taking drugs. The operation leads to a decrease in tremor, stiffness and bradykinesia in the contralateral limbs (on the side opposite from the destruction).

Features of the pallidotomy

Before starting the procedure, the patient's head is fixed on a stereotaxic frame to exclude any head movements during surgery. After fixing the patient's head, a computed tomography (CT) scan is performed to accurately locate the area of ​​the brain that will undergo surgery. In addition, the CT scan allows the neurosurgeon to map out the path to the target. It is important to note that during the operation the patient is conscious: this is necessary for the doctor to be able to monitor the correct location of the electrode and make timely adjustments to the treatment process. Local anesthesia is used, due to which pain during pallidotomy is completely absent.

During the procedure, the electrode is placed through a special conductor (cannula) into the pale ball (basal nucleus of the brain), test stimulation is performed at 46 degrees for 30 seconds. In the absence of side effects such as weakness in the arm, speech impairment, the final ablation is performed with a temperature of up to 75 degrees Celsius.

Efficiency

Pallidotomy is highly effective in the treatment of severe motor disorders and the consequences of drug-induced dyskinesia accompanied by violent movements. All patients after the above destructive surgical interventions showed a positive effect in reducing involuntary movements, rigidity, bradykinesia and tremor. In half of the cases, it was possible to reduce the dose of Levodopa by 50%. In medical practice, they prefer to resort to radiofrequency surgery, because it has a high efficiency and low invasiveness.

Contraindications for stereotactic neurosurgery

There are cases when carrying out thalamotomy and pallidotomy promises more danger than benefit. Common contraindications for surgical treatment include:
- low functional status (less than 70 points on the Karnofsky scale);
- increased intracranial pressure;
- the presence of clinical symptoms of compression of the brain stem;
- the presence or high risk of developing occlusive hydrocephalus in the absence or dysfunction of the ventriculo-peritoneal shunt;
- clinical symptoms of compression of the visual apparatus.

General contraindications also include the impossibility of performing CT (computed tomography) and MRI (magnetic resonance therapy), for example, the installation of a pacemaker. The relevance of medical measures is determined by the doctor during the study of the anamnesis data.