Radiographic Head and Neck Positional Changes in Response to Oculomotor Muscles Tonic Modification Using Low-powered Prismatic Lenses
Phase: NA
Conditions: Postural Neck Pain, Postural Imbalance, Postural Disorders
Sponsor: Lisbon Academic Medical Center - Centro Académico de Medicina de Lisboa

Radiographic Head and Neck Positional Changes in Response to Oculomotor 
Muscles Tonic Modification Using Low-powered Prismatic Lenses
NCT ID not yet assigned
Reviewed in 22.Nov.2025

PhD Project Intent
Doctoral Programme of the Lisbon Academic Medical Centre (CAML)
1. Applicant’s Name:
João Luís Gomes Lopes Alves da Silva
2. Project Title:
Active Cervicocephalic Mobility in Postural Deficiency Syndrome and its Response 
to Treatment with Supero-External Base Prismatic Lenses
3. Supervisor
3.1 Name: Pedro Manuel Gonçalves Silva Fernandes
3.2 Institution: Faculty of Medicine, University of Lisbon
3.3 Curriculum Vitae: Document highlighting publications in the scientific field of 
the proposed thesis, attached to the application documents.
3.4 Supervisor’s Opinion: Document attached to the application file.
4. Co-Supervisors
4.1 Name: Ivo da Piedade Álvares Furtado
4.2 Institution: Faculty of Life Sciences, University of Madeira
4.3 Curriculum Vitae: Document highlighting publications in the scientific field of 
the proposed thesis, attached to the application documents.
4.4 Supervisor’s Opinion: Document attached to the application file.
4.5 Name: Fábio Miguel Vasconcelos Trindade
4.6 Institution: Faculty of Life Sciences, University of Madeira
4.7 Curriculum Vitae: Document highlighting publications in the scientific field of 
the proposed thesis, attached to the application documents.
4.8 Supervisor’s Opinion: Document attached to the application file.
5. Institutions of Execution:
Faculty of Life Sciences, University of Madeira
Faculty of Medicine, University of Lisbon
Posturmed Clinic
CUF Descobertas Hospital

7. Summary
The relationship between ocular and vertebral motor activity is very close and was 
already evident at the foundational moments of neuroscience. When the English 
physiologist Charles Scott Sherrington (awarded the Nobel Prize in Physiology or 
Medicine in 19321) published his major work The Integrative Action of the Nervous 
System—in which he also coined the term proprioception—he demonstrated the 
independence of retinal images in both cerebral hemispheres and their correlation 
with a common ocular motor pathway, thereby achieving a single image 
perception (Sherrington, 1906). Sherrington clearly stated that this motor 
relationship is not exclusive to the ocular muscles but also involves the head and 
the entire body: “[…] the taxis of the lateral movements of the two eyeballs transfer 
thought each eyeball from its own actual sagittal plane to the median sagittal 
plane of the head; and this latter corresponds in the resting position with the 
sagittal median plane of the animal as a whole.”
Half a century after Sherrington’s studies, the French ophthalmologist Jean Benard 
Baron published his science thesis Muscles moteurs oculaires, attitude et 
comportement locomoteur des vertébrés (Baron, 1955). He described several 
experiments on the proprioceptivity of ocular motor muscles in rodents and fish. 
Through surgical manipulation of these muscles, he managed to modify the 
animals’ locomotor patterns: by surgically displacing the position of the eyeballs up 
to four dioptres via partial scleral tenotomies, the animals changed their 
swimming or walking pattern in accordance with the induced deviation.
To clarify the cause of the postural deviation, Baron performed the same 
experiment with blinded animals—obtaining “absolutely identical” results—and 
with enucleated animals, which showed no postural deviation. Based on these 
data, he concluded:

A deviation of the ocular motor muscles of less than 4° provokes a particular 
attitude that varies with the nature of the deviation.

This attitude generates a specific motor behaviour.
1 https://www.nobelprize.org/prizes/medicine/1932/sherrington


These attitudes and behaviours do not depend on vision but solely on the 
ocular motor and paravertebral muscles.

In cases of deviation exceeding 4°, the attitude depends on the position of 
the paravertebral muscles.
In 1979, the Portuguese physiatrist Henrique Martins da Cunha defined the 
Postural Deficiency Syndrome (PDS). He interpreted PDS as a proprioceptive 
dysfunction: in these patients, the sensory information required to construct a 
biomechanical schema—originating from multiple sources (cutaneous, tendinous, 
muscular, articular, visual, and labyrinthine)—becomes discordant, resulting in a 
sensory conflict that distorts the biomechanical schema and overloads the postural 
regulation mechanisms. From the outset, he identified this syndrome as a 
deviation from the ideal biomechanical scheme, producing a complex clinical 
picture variably affecting the musculoskeletal, stato-acoustic, and visual 
proprioceptive systems (Martins da Cunha, 1979, 1987).
The notion of good posture depends on an optimal mechanical relationship 
among body parts, which varies across bodily attitudes over the days and 
throughout an individual’s life. The American Academy of Orthopaedic Surgeons 
(AAOS, 1947) defined posture as the state of muscular and skeletal balance that 
protects the body structures from injury or progressive deformity. Given the 
important anatomical variations of individual vertebral curvatures, it is not possible 
to establish an ideal vertebral dynamic, only to assess variations in vertebral statics 
that maintain the centre of gravity balanced over the plantar support area. This 
equilibrium situation was defined as the “cone of stability” by Jean Dubousset 
(1994). Several authors have defined different vertebral morphotypes and the 
positional and angular limits necessary to maintain vertebral stability within good 
posture (Le Huec & Hasegawa, 2016; Mac-Thiong et al., 2010; Roussouly et al., 
2003; Roussouly & Pinheiro-Franco, 2011; Vaz et al., 2002).
Treatment of PDS offers several options: correction of the “simple deviation from 
the ideal biomechanical scheme” (Martins da Cunha, 1979) can be achieved 
through various sensory modalities. The physiotherapeutic treatment proposed by 
Martins da Cunha consisted of postural correction through positioning and 
breathing exercises (1987). Other modalities include proprioceptive manipulation 

using dental orthoses (Marino & Quercia, 2021) or insoles (Quercia et al., 2007). 
The use of the proprioceptive pathway of ocular motor muscles for PDS treatment 
began in the late 1970s, when Martins da Cunha requested support from the 
Ophthalmology Department of Hospital de Santa Maria to investigate gaze 
deviations he regularly identified in his patients: detecting convergence 
abnormalities became one of the diagnostic criteria for PDS (Martins da Cunha, 
1979, 1987). This finding was later interpreted as an alteration in the 
proprioceptivity of the oculocephalic muscles (Alves da Silva, 1987; Alves da Silva & 
Alves da Silva, 2019; Gagey, 1987; Martins da Cunha & Alves da Silva, 1986a; Roll & 
Roll, 1987; Roll et al., 1991). The collaboration between these two departments 
enabled the development of a PDS treatment centred on postural reprogramming 
and the use of external or supero-external base prisms (Alves da Silva & Alves da 
Silva, 2019).
Over the last century, extensive scientific work has clarified the close relationship 
between periocular and cervical muscles—phylogenetic, ontogenetic, anatomical, 
and functional. Their common origin in the paraxial mesoderm (Pourquié, 2011; 
Schoenwolf, 2021) is expressed, despite the singularity of craniofacial 
development, in a clear anatomofunctional correlation of the motor and sensory 
nuclear columns of the cervical spinal cord and brainstem (Joyce et al., 2021; 
Vishram, 2021). This functional relationship is so well recognised that its absence 
constitutes part of the criteria for brain death (Harvard Medical School, 1968).
Objective of the Project
The aim of this project is to clarify the relationship between PDS and asymmetry in 
active and static axial mobility through an observational study, as well as to assess 
the axial postural effect of prismatic treatment in these patients through four 
studies.
8. Technical Description
8.1 Literature Review
Search Criteria
A preliminary search was conducted in the databases PubMed, LILACS, Cochrane 
Library, and SciELO using the following criteria: “postural deficiency syndrome”, 
“syndrome de déficience posturale”, “Martins da Cunha”, and combinations of at 

least two of the following terms: proprioceptive, proprioception, eye, eyes, neck, spine, 
impairment, impairments, deficit, and deficits.
From these searches, 256 original titles were identified. After reviewing the 
abstracts, 12 scientific articles related to Postural Deficiency Syndrome (PDS) were 
selected. Cross-referencing citations from these articles and evaluating their 
bibliographies yielded an additional 17 relevant articles. Out of the total of 29 
identified, 23 complete articles were obtained.
Axial postural changes are part of the description of Postural Deficiency Syndrome 
(Martins da Cunha, 1979). The author described as a typical PDS pattern an 
increase in both cervical and lumbar lordotic curvatures (Martins da Cunha, 1974, 
1983).
The scientific studies collected on axial postural changes in PDS focus primarily on 
the neurophysiological mechanisms of postural control and the correlation 
between axial posture and oculomotricity (Berthoz, 1987; Buisseret, 1987; Gagey, 
1987; Martins da Cunha & Alves da Silva, 1986b).
Although changes in the amplitude of spinal physiological curves in PDS have been 
described since the first publications, they have never been quantified—clinically 
or radiographically—in subsequent studies, nor has the effect of treatment on 
these curves been measured.
The evaluation of these postural changes in PDS patients is mentioned in several 
studies, often referring to their alteration following treatment; however, none of 
these are prospective or randomized, nor do they clearly specify the vertebral 
parameters before and after treatment. All identified articles in this literature 
review were retrospective, non-randomized, and lacked a clear definition of pre- 
and post-treatment outcomes. No studies using conventional radiography in the 
evaluation of PDS patients were found.
8.2 Objectives
Research Question
Can the use of supero-external base prisms alter axial mobility in patients with 
Postural Deficiency Syndrome?

Working Hypotheses
The use of supero-external base prisms in patients with PDS modifies their 
vertebral mobility.
Active axial mobility in patients with PDS:

Is asymmetric and quantifiable;

Represents a proprioceptive dysfunction;

Can be treated with supero-external base prisms.
Main Objectives
This work aims to:

Demonstrate the axial postural repercussions of using supero-external base 
prisms in patients with PDS.

Confirm the effectiveness of treating these clinical manifestations using 
supero-external base prisms.
Secondary Objectives
1. Quantify the asymmetry of cervical mobility in PDS patients.
2. Correlate this asymmetry with other signs and symptoms characteristic of 
PDS.

8.3 Research Plan, Methods, and Task Description
Materials and Methods
Participant Selection
Inclusion Criteria
The studies aim to include patients who meet the defined diagnostic criteria for 
Postural Deficiency Syndrome (PDS).
We consider the original diagnostic criteria proposed by Martins da Cunha and 
apply the classification of Alves da Silva (Alves da Silva & Alves da Silva, 2019; 
Martins da Cunha, 1987).
The following table presents the characteristic signs and symptoms of PDS as 
defined by Martins da Cunha:
We also include his own description of the physical examination characteristics of 
these patients:
“Patients with PDS present a characteristic body attitude, with rotation of the head, 
trunk, and one of the lower limbs—usually the right—around a vertical axis in a 
clockwise direction. This incomplete rotation results in a typical posture, 
characterised by a particular gaze direction, facial asymmetry, asymmetry of the 

trunk and upper limbs, accentuated physiological spinal curvatures, and a scoliotic 
attitude with lumbar muscle hypertonia and clearly asymmetric plantar support 
(fig. 1).”
The classification used in this study corresponds to Table 1 from the most recent 
publication by Alves da Silva & Alves da Silva (2019).
To establish the diagnosis of PDS, the following criteria are required:

Presence of at least two cardinal signs defined by Martins da Cunha.

Presence of asymmetric plantar support, as described by Martins da 
Cunha.

Presence of asymmetry of head rotation and extension, as described by 
Martins da Cunha.

Presence of directional pseudo-scotomas on synoptophore testing.
The selection of these criteria is based on the inclusion of key clinical features 
defined as central by the original author, associated with signs considered essential 
for proper classification, as expressed in the first three columns of the referenced 
table.

Exclusion Criteria
The following exclusion criteria will apply:

Corrected visual acuity below 8/10 in either eye.

Strabismus.

Nystagmus.


Glaucoma.

History of ophthalmic or vestibular surgery.

Use of medication affecting binocular vision, accommodation, or balance.

Ocular or central nervous system lesion reducing visual field.

Vestibular or otological disease affecting inner ear function.

Known neurological or muscular disorder interfering with postural control or 
gait (e.g., Parkinson’s disease, Charcot–Marie–Tooth, stroke, etc.).

Previous PDS treatment within the last year.
Study Design
The research will be divided into three phases, comprising a total of four distinct 
studies. The study presented here corresponds to Study 3, as stated in the 
following summary table:
Table 3 – Summary of Proposed Studies
Description
Type
Duration
Phase 1 – Population Characterisation
Study 1
Prospective Assessment of the Baseline Characteristics of 
Patients with SDP
Observational
1 year
Phase 2 – Short-Term Outcomes
Clinical Evaluation of Short-Term Prismatic Treatment for SDP
Study 2
Prospective Randomized Trial Against 
Regular Lenses
6 months
Study 3
Prospective (non-randomised)
6 months
Phase 3 – Medium-Term Evaluation of SDP 
Treatment Outcomes
Study 4
Prospective randomised vs regular lenses
9 months

All studies follow the principles of the Declaration of Helsinki (World Medical 
Association, 2013) and will be submitted for approval by the Ethics Committee of 
the University of Lisbon.
Any additional costs arising from these studies will be fully covered by the 
candidate.
The proposed studies aim to assess a set of PDS parameters at different stages 
and in response to treatment. For the current study, these parameters are defined 
in Table 2 below.
Table 2. Parameterisation of Recorded Variables
Description
Measurement Unit
Reference
Radiographic Parameters
 
 
Cervical lordosis, thoracic 
kyphosis, and lumbar lordosis
degrees
2
Global and cervical (C2–C7) 
vertical spinal alignment
millimeters
2
Inclination of C0, C1, and C2
degrees
2
Pelvic incidence, pelvic tilt, and 
sacral slope
degrees
2
Head inclination and rotation
degrees
2
Clavicular angle and 
radiographic shoulder height
degrees & 
millimeters
2
Pelvic obliquity
degrees
2
Hip rotation
degrees
2
The methodology for measurement and recording of these parameters (Table 2) is 
detailed in Annex 1. A summary table of the proposed studies is presented at the 
end of this section.
Evaluation of the Short-Term Prismatic Effect on Spinal Static Posture

This study aims to assess the short-term prismatic effect on the spinal static 
posture of patients with PDS, using radiographic evaluation before and after the 
application of the appropriate prisms.
The radiographic study is conducted using the EOS very low-dose biplanar 
scanning system. This system, which has been duly validated and calibrated for the 
European population, provides exceptional precision for angular measurements 
and is capable of obtaining the aforementioned records in any patient position due 
to its three-dimensional assessment capability of the vertebral column (Le Huec & 
Hasegawa, 2016). The EOS system performs these acquisitions using radiation 
doses significantly lower than conventional digital radiography, with exposure 
levels 5 to 20 times lower. In total, the proposed study results in an expected 
exposure of less than 3 μSv, approximately half the average daily exposure to 
natural background radiation (Hui et al., 2016).
The measured angles follow the criteria defined in the Radiographic Measurement 
Manual published by the Spinal Deformity Study Group (Group & O’Brien, 2005).
Participant Recruitment
Participants will be recruited from patients referred to the specialist consultation at 
a private clinic in Lisbon (Posturmed Clinic).
All adult consecutive patients fulfilling PDS diagnostic criteria will be invited. 
Written informed consent will be required.
The aim is to recruit an initial sample of 12 patients for this study (Julious, 2005). 
Using this initial sample as a pilot study, we will seek to compare the results 
between the two paired observations (before and after treatment) to calculate the 
sample size required to determine the number of participants needed to detect 
differences in the parameters chosen as primary outcomes (see below – statistical 
processing of the data).
The study will have a maximum duration of 1 year after the sample size calculation 
ending earlier if the planned sample size is reached beforehand.

Methodology
The study comprises of three assessment moments:
1. Initial assessment – follows the procedures already defined previously ffor 
diagnosis and treatment prescription, carried out by the ophthalmologist.
Participants will undergo an ophthalmological consultation by a specialist 
experienced in strabology and posturology to confirm inclusion/exclusion 
criteria.
In cases that meet these criteria, it is proposed that all parameters Table 2 
be recorded for the purposes of the study.
In this phase of the study, the ophthalmologic examination, diagnosis, and 
treatment prescription will be performed by an ophthalmologist. The 
candidate will attend this appointment as an observer, only performing the 
formalities associated with the study.
The ophthalmological evaluation, diagnosis, and treatment will be 
performed by Dr Orlando Alves da Silva, Chief Ophthalmologist and former 
Head of the Strabismus Unit, Hospital de Santa Maria / Lisbon University 
Hospital Centre (1977–2005).
2. Pre-treatment radiographic assessment – after the prescribed lenses have 
been prescribed but before their use, this assessment consists of 
performing the examination with the patient standing in their natural 
posture.
3. Radiographic assessment after 15 minutes of treatment – fifteen 
minutes after the patient begins wearing the prescribed glasses with the 
evaluated visual correction (if not emmetropic) and the supero-external or 
external base prisms, according to the established prescription criteria for 
the diagnosed PDS subtype, the radiographic assessment and the 
measurements described in the previous point are repeated.
The EOS system's proprietary software allows for the measurement of all 
parameters defined as clinical outcomes, namely: 


in profile view
o
Sagittal plane
o
Cervical lordosis
o
Thoracic kyphosis
o
Lumbar lordosis
o
Global spinal vertical alignment
o
Cervical vertical alignment (C2–C7)
o
Inclination of C0, C1, and C2
o
Pelvic incidence
o
Pelvic tilt
o
Sacral slope

in frontal view
o
Head tilt and rotation
o
Shoulder tilt and height (clavicular angle and radiographic shoulder 
height)
o
Pelvic obliquity
o
Hip rotation
Statistical Analysis
The sample size calculation for the study will follow the following assumptions:
1. Estimating an expected outcome. In this study, given the absence of robust 
data in the published literature, it is proposed to include a pilot group of 12 
patients to provide a basis for estimation. By analysing this group using 
analysis of variance, it is possible—provided that a normal distribution is 
confirmed—to determine the sample size required to achieve the desired 
alpha level. The following baseline parameters are defined for this 
calculation:

statistical power of 0.8;

α of 0.05;

dropout rate of 0%.

2. Defining a clinically significant value for the outcomes. As no sufficiently 
reliable values exist in the published literature from which to objectively 
determine clinically meaningful differences, the following thresholds were 
selected, each well above the known limits of measurement error:

clinically significant difference in pelvic tilt: 3 degrees;

clinically significant difference in C0 inclination: 3 degrees;

clinically significant difference in cervical spinal vertical alignment: 2 mm.
The analysis of the final results of the study will be carried out, for continuous 
variables, using analysis of variance (ANOVA) and mean comparison tests—
Student’s t-test for paired variables or, if normality is not confirmed using the 
Shapiro–Wilk test, the Wilcoxon test.
8.5 Bibliographic References
Alves da Silva, O. (1987). Scotométrie directionnelle et corrections prismatiques dans le 
syndrome de déficience posturale. Agressologie: Revue Internationale De Physio-
Biologie Et De Pharmacologie Appliquées Aux Effets De L’agression, 28(9), 945–946.
Alves da Silva, O., & Alves da Silva, T. (2019). The Eye and Proprioception. Vision 
Development and Rehabilitation, 5(2), 130–146.
American Academy of Orthopaedic Surgeons. (1947). Posture and its Relationship to 
Orthopaedic Disabilities: A Report of the Posture Committee. AAOS.
Baron, J. (1955). Muscles moteurs oculaires, attitude et comportement locomoteur des 
vertébrés. Thèse de Sciences, Université de Paris.
Berthoz, A. (1987). Regard et posture: Influence de la direction du regard sur le 
contrôle de la posture. Agressologie, 28(9), 893–895.
Buisseret, P. (1987). Développement du système visuel et proprioception d’origine 
extraoculaire et cervicale. Agressologie, 28(9), 913–916.
Dubousset, J. (1994). Three-dimensional analysis of the scoliotic deformity. In S. L. 
Weinstein (Ed.), Pediatric Spine: Principles and Practice (pp. 479–483). Raven Press.
Gagey, P. M. (1987). L’oculomotricité comme endo-entrée du système postural. 
Agressologie, 28(9), 899–903.
Group, S. D. S., & O’Brien, M. F. (2005). Radiographic Measurement Manual. 

Medtronic Sofamor Danek.
Harvard Medical School. (1968). A Definition of Irreversible Coma: Report of the Ad 
Hoc Committee … JAMA, 205(6), 337–340. 
https://doi.org/10.1001/jama.1968.03140320031009
Hui et al. (2016). Radiation dose of digital radiography (DR) versus micro-dose x-ray 
(EOS)… Scoliosis and Spinal Disorders, 11, 46. https://doi.org/10.1186/s13013-016-
0106-7
Joyce, C., Le, P. H., & Peterson, D. C. (2021). Neuroanatomy, Cranial Nerve III 
(Oculomotor). In StatPearls. StatPearls Publishing.
Julious, S. A. (2005). Sample size of 12 per group rule of thumb for a pilot study. 
Pharmaceutical Statistics, 4(4), 287–291.
Le Huec, J. C., & Hasegawa, K. (2016). Normative values for the spine shape 
parameters using 3D standing analysis… European Spine Journal, 25(11), 3630–3637.
Mac-Thiong, J.-M., Roussouly, P., Berthonnaud, E., & Guigui, P. (2010). Sagittal 
parameters of global spinal balance… Spine, 35(22), E1193–E1198.
Marino, A., & Quercia, P. (2021). Stimulations trigéminales bipolaires: Vers une 
orthodontie neuro-sensorielle …
Martins da Cunha, H. (1974–1987). Multiple works on Postural Deficiency Syndrome 
as cited in text.
Pourquié, O. (2011). Segmentation of the vertebrate spine: From clock to scoliosis. Cell, 
145(5), 650–663.
Quercia et al. (2007). Étude de l’impact du contrôle postural associé au port de verres 
prismatiques… J. Fr. d’Ophtalmologie, 30, 380–389.
Roll & Roll (1987). La proprioception extra-oculaire comme élément de référence 
posturale… Agressologie, 28(9), 905–912.
Tavares, C. S. F. da S. (2013). Tradução e adaptação do questionário Convergence 
Insufficiency Symptom Survey (CISS)… Master’s Thesis, Univ. Beira Interior.
Tukey, J. W. (1977). Exploratory Data Analysis. Addison-Wesley.
Vaz et al. (2002). Sagittal morphology and equilibrium of pelvis and spine. European 
Spine Journal, 11(1), 80–87.
Vishram, S. (2021). Textbook of Clinical Neuroanatomy (4th ed.). Elsevier.
World Medical Association. (2013). Declaration of Helsinki. JAMA, 310(20), 2191–2194.

Annex 1 – Parameterization and Measurement Methodology
Ref.
Description
Measurement
Specifications
Musculoskeletal
 Parameters
1a
Head-rotation 
asymmetry
cm and degrees, menton-
acromion distance, 
protractor reading
Patient performs 
maximal active rotation 
avoiding trunk motion.
1b
Head-extension 
asymmetry
cm, tragus-trapezius 
vertical distance
Measured during 
maximal active head 
extension.
1c
Head tilt (neutral)
degrees
Digital AP photograph; 
interpupillary or 
midsagittal line angle.
1d
Head tilt 
(extension)
degrees
Same as 1c during 
maximal active 
extension.
1e
Head extension
degrees
Digital right-profile 
photo, tragus–subnasal 
line inclination.
1f
Foot orientation 
(natural)
degrees
Measured with 
protractor in 
comfortable stance.
1g
Perceived foot 
orientation 
(corrected)
degrees
Patient indicates 
direction of each foot 
with hands while blind 
to feet position.
Radiographic Parameters
2
All measured via EOS software per Radiographic Measurement Manual 
(Group & O’Brien, 2005).
Ophthalmological Parameters
3a
Refraction study
Spherical/cylindrical power 
and axis for each eye; 
prism power/axis; near-
addition in dioptres
Recorded per standard 
optical prescription 
norms.
3b
Interpupillary 
distance
mm at 40 cm
 

3c
Directional 
pseudo-scotomas
degrees, dextro- and 
levoversion
Using Clement-Clarke 
synoptophore (slides 
G3 & G4).
Oculomotor-coordination Parameters (PDS)
4a
Hand–eye test
± (> 1 cm error = positive)
According to Alves da 
Silva & Alves da Silva 
(2019).
4b
Near point of 
convergence
cm to fusion break
RAF rule, 1 cm/s 
approach, pinpoint 
target.
4c
Near point of 
asthenopia
cm to onset of effort
Measured immediately 
after 4b.
4d
Convergence 
Insufficiency 
Symptom Survey 
– V15
total score
Portuguese-validated 
version (Tavares 2013).
4e
PDS 
subclassification
diagnostic record
According to Alves da 
Silva & Alves da Silva 
(2019).