Neurophysiology is a medical speciality whose objective is to perform complementary diagnostic examinations that support specialities such as General Practice and Family Medicine, Sleep Medicine, Neurology, Psychiatry, Child and Adolescent Psychiatry, Paediatrics, Neuropaediatrics, Otorhinolaryngology, Pulmonology and Psychology, among other areas that need to assess functions of the central and peripheral nervous system.

ROUTINE ELECTROENCEPHALOGRAMS (wakefulness and sleep)

The Electroencephalogram (EEG) allows the recording of cerebral bioelectrical activity, non-invasively, by placing sensors on the surface of the scalp. It is performed on patients of all ages, in wakeful rest, i.e., with the patient awake and relaxed.

During the examination, various activation tests are performed, although not all patients meet the criteria for performing all tests. The most common tests are the suspension reaction (opening and closing the eyes), hyperventilation (more intense breathing through the nose and/or mouth) and intermittent photic stimulation (light stimuli at various frequencies).

If you are going to undergo a routine EEG, you should be aware that:
      •    The examination is neither painful nor causes any discomfort, so calmness and relaxation allow for a better quality recording
      •    You should wash your hair on the day of the examination, without subsequently applying gel or hairspray
      •    You should have normal meals; the examination should not be performed fasting
      •    You should bring your usual medication and other examinations you have had

Situations in which the examination is requested:
      •    Headaches
      •    Dizziness
      •    Loss of consciousness
      •    Epilepsy
      •    Cognitive deficit
      •    Dementias

EEG BRAIN MAPPING






EEG Brain Mapping, as a quantitative analysis method, allows the construction of topographic maps in colour gradation and graphic and numerical spectra, using, for this purpose, the Fourier transform. The great advantage of this type of analysis, in addition to visual (conventional) analysis of the tracing, relates to better perception of certain electrophysiological findings, pointing to their possible focal origin and eventual propagation.

Quantitative EEG is currently one of the most widely used methods of EEG analysis in clinical research, being a fundamental diagnostic examination for patients who intend to undergo neurofeedback.

ELECTROENCEPHALOGRAM WITH COGNITIVE TESTS
EEG with cognitive tests refers to the recording of brain electrical activity during the performance of mental functions adapted to different ages. Various tests are added to the routine activation tests (hyperventilation and intermittent photic stimulation), which may include reading, mathematical calculation, association tests and memory tests. This is a particularly useful examination at school age and in the elderly.

EEG with cognitive tests is an asset in studies of:
      •    Brain maturation
      •    Behavioural alterations
      •    Attention deficits
      •    Some language alterations
      •    Learning deficits
      •    Epilepsy
      •    Dementias

PROLONGED EEG MONITORING
Electroencephalogram involving recording of brain activity in wakefulness and sleep, the duration of which varies between 3 and 12 hours.
In cases of poor patient cooperation (for example, in children/adolescents with excessive fear, behavioural alterations or autism spectrum disorder), it is possible to resort to sedation methods, enabling the placement and fixation of sensors, with sedation subsequently reversed in order to record brain activity.
In more extreme situations, these procedures are performed in the operating theatre, with the collaboration of the anaesthesia team.

NOCTURNAL SLEEP POLYSOMNOGRAPHY



Polysomnography is a complementary diagnostic examination in which sleep efficiency is assessed, using, for this purpose, the study of brain, cardiac, respiratory, muscular and ocular activity. This approach is, as a rule, carried out in the laboratory, during the night or, possibly, during the day.

In some cases, non-invasive ventilatory therapy may be applied through auto-CPAP.

If you are going to undergo polysomnography, you should bear in mind that:
      •    The examination is not painful
      •    You may have to sleep in the laboratory and, in this case, bring appropriate sleepwear and your personal hygiene products
      •    You should bring your usual medications and follow the doctor's instructions regarding whether or not to take the drugs on the day of the examination
      •    If you have any dietary restrictions, you should inform us, so as to adapt the first meal of the morning

Restorative sleep is essential for physical, psychological and social well-being. Poor sleep has negative consequences for health, not only in the short term, but also in the long term.

Polysomnography will be an asset in the presence of some symptoms:
      •    Difficulty falling asleep
      •    Nightmares
      •    Sleep apnoea (stopping breathing)
      •    Awakenings during the night
      •    Restless sleep
      •    Headaches upon waking
      •    Snoring
      •    Lack of concentration
      •    Decreased sexual activity
      •    Leg movements/waking with leg pain

MULTIPLE SLEEP LATENCY TEST
The Multiple Sleep Latency Test (MSLT) allows the objective assessment of the patient's degree of daytime sleepiness, i.e., it studies the person's propensity to fall asleep during the day. It involves monitoring brain, ocular, muscular and cardiac activity for several hours. In practice, this examination assesses latency to REM sleep (deepest phase of sleep) during the day, over the course of 5 assessment moments (5 naps) lasting 20 minutes each and with an interval of 2 hours between each nap.
 

HEALTHCARE PROFESSIONALS

Baía de Cascais Clinic – Tel.: 219 236 382*
      •    Specialist Gisela Maia – Licence: C-025070100, issued by: Central Administration of the Health System

*(Standard rate call for the national landline network)