Neurological evaluations are diverse . There is a wide range of methods that can be used to determine whether our brain is functioning in a preserved way, or if on the contrary there is some anomaly.

The technique called cerebral spect is a method which allows to see images concerning the functioning of specific parts of the brain by means of substances that are injected into the subject’s body.

In this article we will review the main characteristics of this evaluation technique, see in which cases it is applicable and its contribution in the pharmacological field.

What is the cerebral spect? Characteristics

Brain Spect is a neurological evaluation tool that consists mainly of injecting a substance through an intravenous medium, which adheres to specific brain structures depending on their chemical composition, and allows the evaluator to observe how that particular area is functioning.

This is possible because the substance injected into the body has a detection mechanism by means of radioactive isotopes , which are added to the patient’s body intravenously. Prior to this, a source of gamma radiation must be applied to the subject. Once this substance is in the organism of the person being evaluated, it mixes with his/her blood until it reaches the brain, and it is there where it adheres to the structure that the specialist needs to evaluate. As mentioned earlier, it is the chemical composition of the substance that will determine which specific structure in the brain it adheres to.

This method, also known as monophoton emission computed tomography, is extremely practical to perform , taking into account that it does not require any complex preparation. It is only the application of gamma radiation to the patient to subsequently perform the intravenous injection into the body. Then the substance is in charge of making the tour and showing the areas of interest

The estimated duration of this method is approximately one hour, calculating the entire aseptic process prior to application.

What do you evaluate?

Basically, there are three aspects that this test allows to evaluate. This is the study of brain perfusion, tumour viability and brain receptors.

1. Brain perfusion

It is evaluated by means of radioisotopes, which depending on the patient’s blood flow level will be fixed in the brain tissue . This procedure provides significant information on vascular pathologies that are difficult to detect with other tests.

Apart from that, it is also effective in showing indirectly how the activity of the neurons is. This aspect is of great importance in the field of psychiatry.

2. Tumour viability

This is done using tracers that do not pierce the blood vessel network, which remains intact. These tracers are actively incorporated into the subject’s body as potassium analogues.

The importance of this evaluation lies in determining tumour conditions or natural changes in the organism as a result of a surgical intervention .

3. Neuro-receptors

Finally, this analysis allows us to evaluate the density and distribution of the different receptors that the Central Nervous System (CNS) has . This is achieved thanks to specially marked emitting isotopes for the procedure.

This aspect is the most recent in terms of brain spectrometry evaluations. Despite this, it has shown a fairly good degree of effectiveness when required.

In what cases does it apply?

This form of evaluation has been shown to be extremely useful in a wide variety of cases; it is even capable of detecting neurological and psychiatric abnormalities that other techniques overlook.

Some of its most frequent uses are in cases where the extent of cerebrovascular disease (CVD), Parkinson’s disease, dementias in all its forms, and epilepsy need to be evaluated. In these assessments, the cerebral spect is extremely effective. It is also capable of recognizing areas of the brain with a lower than normal blood supply , which translates into a very effective form of prevention for cerebrovascular disease.

In the case of epilepsy, this assessment technique can capture the irritative focus during the seizure by means of a photogram, which helps to determine exactly which area of the brain is affected and to proceed with the necessary intervention.

As far as psychiatric diseases are concerned, it is of great help in establishing the differential diagnosis between disorders , and largely clarifies when it is a question of a particular dementia. It also provides information in the recognition of multiple more complex neuropsychiatric pathologies.

Contributions to pharmacology

In the field of pharmacology, the cerebral spect has been very useful, helping to determine which drugs are more efficient when iterated with the nervous system, especially the drugs that inhibit neurotransmitters .

Taking into account that this technique allows us to see clearly how the route of the drug in the body is, the level of blockage towards a certain substance and when its effect can last before a new dose is necessary.

Bibliographic references:

  • Dougall NJ, Bruggink S, Ebmeier KP (2004). “Systematic review of the diagnostic accuracy of 99mTc-HMPAO-SPECT in dementia”. Am J Geriatr Psychiatry. 12 (6): 554 – 570.
  • Scuffham J. W. (2012). A CdTe detector for hyperspectral SPECT imaging. Journal of Instrumentation. IOP Journal of Instrumentation. 7: P08027