ahp Flashcards
what is a normal head posture
When the body is erect and facing forwards
The median plane of the head is continuous with the median plane of the body
what is an ahp
Compensatory head posture’
Consist of:
Head turn to R or L (Face turn)
Chin elevation or depression (Head up/ Head down)
Head tilt to R or L shoulder
May exist singly or combined
Torticollis: AHP includes a head tilt
what are non ocular causes of ahps
Congenital
Contracture of sternocleidomastoid muscle in neck
Head tilt to affected side
Head turn to unaffected side
May adopt chin elevation (head up)
Acquired
Deafness - unilateral/ asymmetrical
Head turn to more affected side
Shyness
Often chin depression (Head down) and variable
Mental retardation
Often variable AHP
Habit
Neurological – brain tumour
Arthritis / rheumatism
Disorders/ injuries of spine
what are ocular causes of ahp
Obtain/ maintain BSV
Incomitant strabismus
A & V patterns
Separate diplopic images further
Insuperable diplopia
Gain foveal fixation
Infantile esotropia
Gross limitation preventing foveal fixation in PP
Optimise VA
Refractive errors
Nystagmus
DVD
Head tilt towards fixing eye appears to ↓ DVD
Centralise field of vision
Bilateral ptosis
Gaze palsies
Homonymous hemianopia
Avoid pain
Graves Ophthalmopathy
Blow-out #
what is the diagnostic value of ahp
Diagnostic
Aids in diagnosis of affected EOM in palsies
Aids in differential diagnosis of longstanding versus recently acquired palsies
Degree of AHP < in longstanding palsies
Patient less aware of AHP in longstanding
Presence of pre-existing BSV
how to assess ahp
Ensure patient sitting / standing straight
Observe patient on same level, directly in front
Note any facial asymmetry
Assess if one ear more visible than other
Check eyes are level
Observe chin position from side
Straighten head and allow patient to resume “normal” position
Observe AHP for 1/3m, 6m, when performing visual task
Old photos may identify duration of AHP
Ask patient if aware of AHP
how to differentially diagnose ahp
straightening head is difficult/ impossible for someone who has congenital non ocular
for ocular congenital straightening head is easy
congenital non ocular aware of ahp - may be
ocular - unaware - longtstanding - aware and without tech ache -acquired
congenital - non ocular - usually asymptomatic
congenital ocular may be symptomatic
congential non ocular have bsv without and without ahp
ocular bsv with ahp without ahp diplopia / suppress
ct congential non ocular nad
ocular congential- presence of strabismus / nystagmus
om are full in congenital non ocular in ocular muscle imbalance
hess is normal in congenital non ocular in ocular there is a muscle imbalance
how to differentially diagnose a ahp between congenital non ocular and ocular
when you occlude one eye of congenital non ocular they have non change in app
with ocular - head straightens on occlusion of paretic eye
ui ocular va testing -no change of ahp in congenital non ocular
ocular may change to improve va if presence of nystagmus
medical congenital ntial non ocular ppl have indications for reasons for adopting ahp example deafness aqs a pose to those with ocular problems that may be with illness relevant to muscle imbalance
how to record ahp
Define
Small, moderate, marked
Variable or alternating
Distance(s) AHP noted
Present with and without optical correction
how to manage ahp if asymptomatic
Asymptomatic
Small
relieve diplopia and/or pain
No active treatment
how to manage ahp if symptomatic
Symptomatic
Small-moderate AHP
Relieve using prisms, occlusion
Botulinum toxin injection
Surgery
how to manage ahp if they are symptomatic and have a marked ahp
Symptomatic
Marked AHP
Indication for surgery
Neurogenic palsies
Mechanical palsies
Nystagmus
Young children- prevent secondary contractural neck changes
Affect amount of surgery
Consider under-correct if longstanding
what are reasons for a head turn
Purpose
Move eyes away from field of action of paresed muscle
Move eyes to a position where deviation is least
Enable eye to fixate centrally – gross limitation
Permit the use of the nose as an occluder
Utilisation of VOR
Head turn L eyes move R
Paralytic strabismus:
Head turned in direction of paresed muscle
if someone has a right left palsy where will there head turn be
In right lateral rectus palsy, the affected eye will have difficulty moving outward towards the right side. To compensate for this, the person may adopt a head posture where they turn their head to the right to align their eyes and maintain binocular vision. This is known as a compensatory head turn. The head turn is usually towards the side of the affected eye, so in this case, the person would likely turn their head to the right.
if someone has a left superior rectus palsy where will there head turn be
Head turn left
if someone has right duanes type b what head posture will they adopt
In Type 1 Duane syndrome, there is limited or absent abduction (outward movement) of the affected eye. To compensate for this, the person may adopt a head posture where they turn their head to the opposite side of the affected eye to align their eyes and maintain binocular vision. This is known as a compensatory head turn.
In the case of Type 1 Duane syndrome affecting the left eye, the person would likely turn their head to the right to align their eyes, as this movement would bring the left eye closer to the midline. Conversely, if the right eye is affected, the person would likely turn their head to the left
what are reasons for chin elevation/ depression
Purpose
Move eyes away from field of action of paresed muscle
Utilise physiological V pattern
For comfort – mechanical
Head up (Chin elevation)
Eyes relatively depressed
Relative convergent position of eyes
Head down (Chin depression)
Eyes relatively elevated
Relative divergent position of eyes
if someone has a right inferior rectus palsy where will they turn their head
If someone has a right inferior rectus palsy, they may turn their head to the left in an attempt to compensate for the resulting double vision (diplopia). This is because the inferior rectus muscle is responsible for downward and inward movement of the eye. When the muscle is paralyzed or weakened, the affected eye may be unable to move downward and inward, causing the person to see double when looking downward and to the right. To avoid this, they may turn their head to the left to align the affected eye with the object of interest, thereby reducing the degree of double vision
what head posture would someone with left browns syndrome adopt
In Brown syndrome, there is limited or absent elevation of the affected eye when looking inward or upward. To compensate for this, the person may adopt a head posture where they tilt their head away from the affected eye and chin down towards the opposite shoulder. This is known as a compensatory head tilt.
In the case of left Brown syndrome, the person would likely tilt their head to the right and chin down towards the right shoulder to help the left eye move inward and upward.
what are the reasons for a head tilt
Purpose
Overcome torsional displacement
Overcome vertical displacement
when the head is straight where are the vertical meridians
When the head is straight the vertical meridians of the eyes are parallel
When the head is tilted RIGHT, RE intorts due to RSO & RSR contracts and LE extorts due to LIO & LIR contracts
When the head is tilted LEFT, LE intorts due to LSO & LSR contracts and RE extorts due to RIO & RIR contracts
If LE is extorted in PP , a head tilt to the RIGHT makes RE intort = vertical meridians are parallel
what does a head tilt cause
Head tilt also causes vertical movement
Head tilt L
LE sl depressed & RE sl elevated
LE moves up sl & RE moves down sl to neutralise
Head tilt always towards side of hypotropic eye
Superior muscles (SR & SO) tilt and turn same way
Inferior muscles (IR & IO) tilt and turn opposite ways
how to measure head posture in clinic
Often an estimate – slight, moderate, marked
Photographs
Goniometer
Cervical range of motion (CROM) instrument
designed to assess the range of motion in the cervical spine
how to measure head posture in clinic use of tech
Use of technology to measure head posture
The Cambridge Face tracker
iPhone compass function
May be possible to use but require further research
head turn is towards the field of…….
Head turn: towards field of action of paresed muscle
head tilt is towards the….
Head tilt: towards side of hypotropic eye
head up - chin elevation is towards
Head up (chin elevation ): moves eyes away from field of action of paresed muscles (SR & IO)
head down - chin depression is towards….
Head down (Chin depression): moves eyes away from field of action of paresed muscles (SO & IR)
if someone has a left blow out fracture without pain on attempted elevation where will they turn there head
If someone has a left blowout fracture without pain on attempted elevation, they may turn their head to the right in an attempt to compensate for the resulting double vision (diplopia). This is because a blowout fracture typically involves a fracture of the orbital floor, which can lead to the entrapment of the inferior rectus muscle or other orbital contents. As a result, the affected eye may be unable to move downward and inward, causing double vision when looking downward and to the left. To avoid this, they may turn their head to the right to align the affected eye with the object of interest, thereby reducing the degree of double vision
if someone has a left superior oblique palsy where will they turn there head
f someone has a left superior oblique palsy, they may tilt their head to the right and slightly tilt their chin down to compensate for the resulting double vision (diplopia). This is because the superior oblique muscle is responsible for inward and downward movement of the eye. When the muscle is paralyzed or weakened, the affected eye may be unable to move inward and downward, causing the person to see double when looking downward and to the left. Tilting the head to the opposite side can help to align the eyes and reduce the degree of double vision. It’s important to note that the exact compensation strategy may vary depending on the individual and the extent of the palsy.
if someone has a left medial wall blowout with medial rectus muscle entrapment where will they move their eyes
n a left medial wall blowout fracture with medial rectus muscle entrapment, the left eye would have restricted movement, particularly in the medial direction. This means the person would have difficulty moving the left eye towards the nose.
As a result, the person may compensate by avoiding movements that require medial rectus function, and instead, move their right eye towards the object of interest to maintain binocular vision. This is known as an ocular tilt reaction, where the eyes and head tilt towards the opposite direction of the affected eye.
So in this case, the person would likely move their right eye towards the object of interest and tilt their head to the right to align their eyes and maintain binocular vision.
where would someone move there head with a left inferior rectus palsy
