Anatomy of the head – the essentials for surgical practice

The skull

Neurocranium – anatomic landmarks

Glabella –frontal proeminences

Bregma – coronal suture Lambda – crossing between the sagital and lambdoid sutures

Facial bones – anatomic landmarks

Nasion

Alveolar depression

Mentonier point

Gonion

Malar point

Dacryon

Projection of viscus and bones

The eyes: what is apparent and what should we

see?

Anatomy of the eye

The pupilary reflex

Near sight reflex

The ear:Testing the vestibulary apparatus an

hearing

Test for normal hearing

Test for balance

Walk on s narrow pathway

Romberg test for balance

Nasal cavity and paranasal sinuses

Nasal cavity and paranasal sinuses

Oral Cavity

Clincal signs in cranio-cerebral trauma

Why do we discuss in conjunction skull and

cerebral lesions?

Direct impact

ACCELERATION: traumatic agent is moving while the head is immobile.Produces an area of depression of the

skullDecreases the kinetic energy of the

traumatic agent – energy transfer Limited extra space – impact on the brain

which does not have an escape route

Direct impact

DECELERATION: the head in move stops abruptly when hitting an immobile strong surface. Kinetic energy transmits to the skull and

cerebrum Cerebrum continues to move after the skull

stops. Secondary trauma to the brain while hitting the bony irregularities: back of orbit and sphenoidal bones (ridge)

Direct trauma

BILATERAL COMPRESION: sudden compression with reduction of normal convexity

Direct trauma

ROTATIONAL ACCELERATION – complex mechanism where a combination of acceleration and deceleration prdoduces a rotational movement

Indirect trauma

Physical force does not action on the head but produces lesions from a distant impact.

Although produced by different type of impact, pathogenic mechanisms are similar with those presented for acceleration and deceleration.

Indirect trauma

Sudden flexion or extension = produces movements of the skull and cerebrum with different speeds the brain is pushed against the hard skull and is injured.

Landing on feet or ischiatic protuberances

typical mechanism is that of counter-hit

Clinical examination

History: thorough evaluation of the mental status and neurological effects as traumatic effects may determine primary consequences (neurological disturbances, dilacerations) , secondary (accumulation of fluids) or late effects (cerebral edema). Time schedule can be very important in judging severity. Evaluation of conscience – a superior form of reflection of the objective world – 90% of head trauma present an impairment of consciousness.

Clinical examinationImpairment of consciencesness : Agitation: motor/ psychological - motor Stupor: no tendency to move spontaneously and

indifference – conscience status appears to be suspended

Obnubilation (difficulties in responding to questions, as if in superficial sleep

Mute and akinetic Lack of initiative and less impressed about people

around him Confused Coma – partial or total loss of conscience and

other function that relate a human being with the environment, chenges in vegetative functions

Definitions are to complex + a lot of subjectivism = confusion in terms

GLASGOW Coma ScaleInternational accepted grading for the

conscience status0-8 9-12 13-15

0-8 9-12 13-15

Evaluation of vegetative function

RespirationCirculationThermal homeostasis

Clinical examination

Muscular tonus Back of the head Limbs Ability to sustain the forearm or ankle (integrity of the

pyramidal pathway) Rigidity by lack of cerebral function(extension of limbs) Rigidity by lack of functional cortex (flexion of limbs)

Testing sensibilityEvaluation functionality of cranial nerves – in particular for lesions with fracture lines in the base of the skull.

Cranial nerves

Olfactiv N. (I)

Fracture lines involve the fine perforated bonny structure of the etmoid bone, through which the nerve fibers pass inside the skull.

The patient if conscientious acuses anosmia impossibility to sense any odor), usually it is unilateral !!!

Optic N (II)

Lesions in the middle fossa, between the optic chiasm and the eye – blindness (different areas according to lesion)

Concussions may be reversible

Section of the nerve is always followed by atrophy and definitive blindness.

Motor nerves of the eye (oculomotor III)

Motility disorders with the consequent double vision

Ptosis of the eye lid (unilateral)

Divergent strabismum

Midriasis (unilateral)

Motor nerves of the eye (abducens IV)

Palsy of the great oblique muscle with impossibility to look below and outward

Double vision depending on the position of the view

Trigeminal (V)

Decrease sensibility or anesthesia in the respective cutaneous sensitive areasMotor branch – difficulties in mastication and lateral deviation of the mandibleOphthalmic branch – lack of corneal reflex

Extern oculomotor (VI)

Convergent strabismus, with deviation opposite in direction to the normal movement of the nerve

Facial nerve (VII)Facial asymmetry Deviation of the mouth towards the normal sideLabial corner lowered on the affected side Eye-bulb on the affected side appears largerAcoustic/vestibular syndrome may be associated when the fracture involves the base of the skull

Acustico-vestibular nerve (VIII)

Audition: Abnormal sounds Auditory deficit

Vestibular:Only in cases with unaltered conscience

the patient may suffer from dizziness or vertigo

Glosopharingeal nerve (IX)

Mixt composition motor and sensitive compoentsDeglutition problem (palsy of the superior

constrictor of the pharynx)Absent pharingeal reflexHipoestesia or anestesia of the pharynx

and posterior third of the tongue

Vagus nerve (X)

Palsy of the soft palate

Palsy of the recurrent nerve with voice characterized by bitonality

Changes in respiration and cardiovascular activity

Spinal (XI)

Palsy of sterno-cleido-mastoidian nerve and trapesius. Shoulder is abnormally low and the patient can not move the scapula away from the midlineThe sterno-cleido-mastoidian on the affected side does not contract when the head is moving.

Hipoglosal nerve (XII)

Atrophy of half of the tongue

Deviation of the tongue towards the affected side

Cranio-cerebral concussions

There is significant difference in terms from soft tissues concussions: in head injuries it is possible

the skin to be continuous, but a fracture to produce endocranian infection

1. Concussions of the scalp

Particularities: deep fascia slides over the skull (periostum) and as such it is very mobile

The scalp is a complex structure that behaves as an entity. It has numerous fibrous structures that produces honey-comb spaces that comprise blood vessels.

1. Concussions of the scalp

Haematoma of the skull – may appear during delivery in the skull of babies in the area of presentation of the head. It is a cutaneous bloody suffusion It has a tumor-like appearance which can

be deformed while pressing it and will be reabsorbed in days.

1. Concussions of the scalp

Subcutaneous hematoma: Direct impact Painful swelling (spontaneous or after

manipulation0 Relatively soft (deformable) but may be hard (in

tension) If large enough can present a softer area in the

middle which can produce “thumb-printing” Specific sound – crepitating – similar when

crushing snow in your hand) – poses a risk of confusion with the sound of moving bony fragments

It develops under the deep fascia and can migrate in adjacent area

1. Concussions of the scalp

Subperiostal hematoma Blood suffusion developing between the external

layer of the bone and the periosteum after the rupture of epicranial vessels

Develops typically after a difficult delivery or forceps application

Most frequent in the parietal region It is a round or oval structure with central

liquefaction It may transform in bony structures

2. Concussions of the skull

Fractures produced at the impact area or distant fractures radiated from the impact areaFractures can be: Localized Radiating towards the base of the skull

Fractures Incomplete (only one of the bony layers) Complete (both layers)

2. Concussions of the skull

Fractures - simple or multiple

Fractures - with detached fragmentsWith or without protrusion inside the skull

cavityWith or without lesions of the cerebrum

Fractures of the base of the skull

Resistance arches that are continuous with those on the skull cap

Transmit forces away from impact zone

Frontal impact

Radiation of the fracture towards the anterior or middle foosa of the base

Major risks : orbital cavity, optical nerve, oculomotor and abducens.

Temporal impact

Can radiate in any segment of the base

Frequently fractures of the petrous portion

Can produce lesions in the inner ear

Occipital impact

Risk to radiate toward the middle and anterior fossa of the base

Simptomatology

Many do not present any symptomsEpistaxis Periorbital hematomaBilateral subconjunctival hemorrhageHemorrhage exteriorised through the earPerimastoidian hematomaHematoma developing in the posterior pharingeal subbmucoasaLicvoreea (cerebrospinal fluid)

Epistaxis

Suggest a fracture of the anterior fossa

Etmoid fracture + vessel disruption

Careful to exclude other possible diagnosis

Bilateral periorbital hematoma

Unilateral is rare and is typical produced by direct impactBilateral: blood originates in the anterior or middle fossa and migrates towards the orbit and periorbital tissues. Characteristic for base pf the skull fractures

Bleeding from the ear

Highly suggestive for base of skull fractureMiddle fossaOriginates in timpanic vessels, middle ear or vessels around petrous portion of the temporal bone. Fracture of the petrous portion should be made after excluding other entities (open fracture)

Otorahia and retro/perimastoidian

hematomaMiddle fossa fractures

The typical afected vessel is the mastoidian vein

Posterior fossa fractures

Licvoreea (loss cerebrospinal fluid)

Cristal clear liquid

Exteriorization in many alternatives

It reveals a fracture of the base of the skull (or a panetrating injury)

Loss of fluid can be continuous or discontinuous)

OPEN FRACTURE