Proper selection of patients for the DBS procedure is essential
success factor for this therapy. Deciding on
treatment with deep brain stimulation in a patient with PD is
complex and multifactorial task. After conducting multiple
multigroup studies of DBS in North America and
Europe has led to the development of relatively uniform recommendations for the selection patients for treatment.

Diagnosed idiopathic PD based on generally accepted
diagnostic criteria, is the most important criterion for making a decision
about the DBS. Given the fact that 8.1-25% of parkinsonism diagnoses
are incorrect in the early period, even among experts, it is recommended
dynamic review of patients before making an O DBS decision. Lots of
Studies have shown that the administration of DBS to patients with parkinsonism,
such as supranuclear palsy, multiple system atrophy, dementia
with Lewy bodies and vascular parkinsonism, do not give a clinical effect, but
in some cases even worsen the course of the disease [70].
Duration of the disease and its stage.
Considering that for the development of PD, which is difficult to correct
medications, which has levodopa-induced complications, requires
at least 5 years, when the stage of the disease becomes at least 3 according to Hen-Yar, then
this is a positive criteria for resolving the issue of DBS.
Positive response from levodopa.
Many authors believe that a good response to treatment with levodopa
is one of the best predictors of DBS STTN. To assess the response of levodopa
for symptoms of PD, the levodopa test is used in clinical practice. At
this improvement in motor functions by at least 30% in the Med-off-state (12
hourly withdrawal of levodopa) according to the UPDRS scale (III part) is a positive response. Using a suprathreshold dose of levodopa (usually 1.5-2 times the dose) elicits an optimal response and may also cause drug-induced dyskinesia, which is also a symptom for treatment.
The presence of dyskinesias and motor fluctuations.
The presence of levodopa-induced complications is the main goal
BP surgery. Most series of pallidotomies showed excellent results
treatment of levodopa-induced dyskinesias in 65-100% of cases. The same
results were obtained with DBS. The reduction of dyskinesia plays an important role
role in improving the quality of life.
Age.
The maximum age at which DBS was performed was 78 years.
Many authors recommend having an age limit of 70 years, some 75 years.
Welter et al. concluded that treatment outcomes in a group of young
patients (<56 years) were better than in the older group (>56 years) [71]. However,
many experts consider various disorders associated with age
(cognitive impairment, comorbidities, poor effect of
levodopa, etc.) more important factors than just the age of the patient
[72]. Despite this, DBS is not recommended for patients older than
75 years old, due to the high risk of intervention, as well as due to limited
life expectancy. In such cases, it is preferable to
unilateral ablative interventions.

Accompanying illnesses.
Despite the lack of research on the effect of concomitant
diseases for the DBS procedure, it is not recommended to carry out this procedure
patients with unstable cardiac pathology, acute infectious
diseases, significant atherosclerotic encephalopathy, or
other cerebrovascular diseases, oncological pathology,
significantly reducing life expectancy, and
all other diseases and conditions that may lead to
significant reduction in DBS treatment outcomes and cause significant
surgical risks.
Neuroimaging data.
Many studies indicate that any structural pathology
brain, with the exception of moderate atrophy, should be considered
as an exclusion criterion for DBS. These criteria also include
radiological signs characteristic of other diseases of the brain
brain, including large tumors, malformations, convexital
cysts. Presurgical neuroradiological diagnosis is very important
multisystem atrophy, supranuclear palsy, metabolic
diseases (Fara's disease, etc.) with the deposition of substances in the basal ganglia.
In some cases (Fara's disease) it is necessary to conduct along with MRI
computed tomography.
Neuropsychological and neuropsychiatric aspects.
Dementia is a contraindication for DBS due to
for a high risk of aggravation of this condition after surgery. AT
in exceptional cases, the procedure can be carried out, however
need information support of the patient's relatives about
possible worsening of dementia in the postoperative period.
behavioral factors.
There are general guidelines for the presence of neurobehavioral
contraindications for DBS. These include primary mental
disorders, primary uncompensated bipolar disorders,
severe, refractory, depression, severe addictions
from various substances, severe personalized disorders.
Before making a decision on DBS, it is necessary to evaluate the history and
actual psychiatric status of the patient. Decision must be made
individually based on symptom severity as well as response to treatment
present and past symptoms. Other psychological
factors may be cognitive reserves, attitudes towards medications, patient response to proposed surgical treatment, attitudes and trust in specialists, etc.
Severe depression in the preoperative period is a condition for
its further progression. Therefore, a patient diagnosed
severe depression should not be affected by DBS until the depression is cured.
Thus, the issue of selecting patients for the DBS procedure is
complex task of a neurologist and related specialists. Condition
A positive result of stimulation is the correct selection of patients.
Summarizing the above, below is a short list
selection criteria for surgical treatment in PD:
1. The age of patients is up to 70 years.
2. The duration of the disease is five years or more;
3. At least stage 3 PD on the Hen-Yar scale.
4. The impossibility of adequate control of the disease with the help of
medicines;
5. The presence of levodopa-induced fluctuations and dyskinesias, and
as well as the associated decrease in the quality of life;
6. Positive
levodopa test: decrease
movement disorders on the UPDRS scale by 30%;
expressiveness
7. Absence of pronounced somatic, mental disorders.
Similar to STN-DBS are indications for pallidotomy - advanced
stage of Parkinson's disease, the presence of rigidity, tremor and bradykinesia,
complications of drug therapy - fluctuations, dyskinesia. Best
a candidate for thalamotomy is a PD patient who is tremor-dominant.
Indications for ablative surgery are more liberal in terms of
age and duration of illness, impairment of cognitive status is not
contraindication for ablation. Therefore, ablative surgery is
method of choice in patients who were not included in the DBS candidate group by topic
or other reasons, but requiring surgical intervention due to
presence of evidence. Also an important factor in the decision to
form of neurosurgical intervention is the possibility of permanent
arrival of the patient at the clinic, remoteness from specialized care,
poor living conditions that may increase risks
postoperative complications and possibilities for their solution, lack of
confidence that the patient or his relatives will be able to correctly
use a stimulant. This means that suitable patients
for DBS, but having the above difficulties, it is better to
ablative interventions.
Patients undergoing surgery should
receive a full range of examinations and treatment from a neurologist. Patients
are assessed according to the universal disease assessment scales (Hoen-Jar,
UPDRS, etc.). It is important to identify the main symptoms,
disturbing the patient in order to suggest the effects of surgery before
operations. Also important neuropsychological evaluation of patients.
Before surgery, any infectious focus in the
the patient's body (carious teeth in the oral cavity, ENT pathology
sinusitis, otitis, skin infection, etc.). Patients with arterial hypertension have an increased risk of hemorrhage, so such patients should be medically compensated. One week before
surgery, the doctor should stop taking medications that
may cause hemorrhage (aspirin, anticoagulants), non-steroidal
anti-inflammatory drugs. Antiparkinsonian drugs
can be canceled at least 8-10 hours before surgery to detect
parkinsonian symptoms.