Investigation of Neurogenic Palsies
Concomitant – angle of deviation same fixing either eye and in all positions of gaze
Incomitant – angle varies depending on fixing eye and direction of gaze
Incomitance is caused by:
• Neurogenic palsies
• Mechanical limitation
• Anisometropia
Neurogenic palsies
• Nerve supply to muscle is affected
• Can affect 1 muscle or group
• Consider observations and determine further investigations that may be required
• Recording findings as evidence of recovery, regression and stability
VA – normal though may be reduced in:
• Traumatic mydriasis
• Previous amblyope
• Related neurogenic conditions i.e. MS
• Recent reduction in VA can lead to decompensation of longstanding palsy
• Coincidental pathological cause
Things to consider:
• Deviation in primary position
• Fixing with unaffected eye – primary deviation
• Fixing with affected eye – secondary deviation
Figure 1 – A diagram showing the positions of each vertical muscle in both
• AHP to avoid deviation
eyes.
AHP
• Turn/tilt/elevation/depression
• Places eyes away from action of affected muscle
• On CT, record AHP, size and type of deviation
Observations during OM
• Smoothness of movements during smooth pursuits
• Head movements in child indicative of avoiding affected movement
• Pupils, lid position and changes
• Globe position and changes and nystagmus
• Versions, ductions and determine development of muscle sequelae
• BSV
• Normal or potential BSV most common – suppression/AC and diplopia ?
• Traumatic loss of fusion possible
• Measurements – c/s AHP/gls/N and D
• Investigate c Lees screens, uniocular field of vision and BSV field
,Muscle Sequelae, Diplopia Charts, and Interpretation of Hess Charts
Muscle sequelae – sequence of EOM adaptation following muscle weakness
• Sherrington’s – uniocular, innervation sent to muscle equivalent decrease innervation
sent to direct antagonist
• Hering’s – binocular, impulse to one muscle to contract, equal innervation sent to
contralateral synergist to contract
1. Primary u/a
2. Contralateral synergist o/a – Hering’s
3. Ipsilateral antagonist o/a – Sherrington’s
4. Secondary inhibition of contralateral antagonist – Hering’s
Factors affected muscle sequelae
• Above is expected pattern - develops overtime - primary u/a is largest
• Fixing eye could be affected or unaffected eye
• Takes time to develop, becomes more concomitant over time
• Primary deviation – fixing with unaffected eye
• Secondary deviation - fixing with affected eye
• Secondary deviation > primary – this differentiates between recently acquired and
longstanding
Diplopia charts
• Patient describes diplopia – red green goggles at 50 cm
• Drawn on chart – 9 positions of gaze
• Good for impaired OM and bilateral asymmetrical 4th nerve palsies
• Identify crossed and uncrossed
• Higher image from lower eye – lower image from higher eye
• Extorted eye sees intorted image – intorted eye sees extorted image
• Lines furthest away – greatest separation of diplopia
Hess charts – Lees screen
• Inner field 15 degrees and outer field tested at 30 degrees
• Position – higher field is higher eye, inward shifted is esodeviation
• PP deviation – cannot tell if tropia or phoria – 1* fixing unaffected 2* fixing affected
• Size of field – smaller = primary limitation in that eye
• u/a – inward displacement of dots – 1* u/a is largest displacement
• o/a – outward displacement of dots in direction of o/a contralateral synergist
• Mechanical – flat and narrow field – reversal in opposite pos. of gaze
• Equal sized field – symmetrical limitation and longstanding palsy = concomitance
• Sloping field – A and V pattern
• Hess charts are used in line with other tests and used as a way to compare changes in
recovery, regression and stability overtime
,Aetiologies of Acquired and Congenital Neurogenic Palsies 1
Aetiologies – causes of the palsy
• Interruption to neural supply
• Interruption to blood supply
o Small ischaemic attacks due to blockage or bleed – common in elderly as isolated palsies
o Recovery rate is high – 90% of 3rd NP by 6/12 according to Akagi et al. (2008)
o Risk factors – diabetes, arteriosclerosis and hypertension
o Patel et al. (2005) – diabetes risk factor for 6th NP – x6 increase w/ diabetes, x8 increase w/
diabetes and hypertension – hypertension alone = no increase
o Jacobson et al. (1994) – diabetes causes 5.75x increase in 3rd NP – left ventricular
hypertrophy cases 5.5x increase not caused by hypertension alone
o Cocaine – differential diagnosis for 3rd NP especially in young
o Giant cell arteritis – inflammation of blood vessels – 6-70% irreversible vision loss – med.
age is 75 years – Kawasaki and Purvin, (2009)
o Erythrocyte sedimentation rate – more than 50mm/h for 96% of patients – normal 0-30mm/h
o Signs – jaw claudication, head ache, weight loss, anorexia, fever, anaemia etc.
o Symptoms – vision loss, diplopia, eye pain, amaurosis fugax
o Ocular ischaemic lesion – ant. isch. optic neuropathy, cent. Retinal vein occl., cilioretinal
artery occl., post. isch. optic neuropathy
• Intracranial vascular abnormality
o Aneurysm – persistent localised dilations of a blood vessel wall – result of trauma, infection
and inflammation – symptoms due to pressure, bleeding and rupture
▪ Internal carotid and posterior communicating artery – 3rd NP
▪ Intracranial portion of internal carotid – compression of visual pathway
▪ Cavernous sinus – 3rd and 6th NP, isolated 6th NP w/ ipsilateral Horner syndrome
o AVM – congenital – arterial and venous circulation – problematic in 2nd and 3rd decades of
life – headaches – symptoms due to compression, haemorrhage, ischaemia and vascular
steel
o Fistula – abnormal connection between carotid artery and cavernous sinus
▪ Traumatic or spontaneous – high and low velocity – direct and dural – internal/ext.
▪ See diagram
▪ Trauma/vascular/tumour
▪ Tumours – 4th and 6th nerves commonly affected – 3rd NP post pituitary tumours
▪ Trauma – 4th NP susceptible to closed head trauma
▪ Idiopathic intracranial hypertension – more in females and obese – headache etc.
▪ Intracranial hypotension – following dural puncture , headache
▪ Diabetes – 3rd and 6th nerves most affected – pupil spared
o Pupil in 3rd NP – aneurysm compresses 3rd N → iris sphincter spared
o Aberrant regen. – occur 6+ weeks after onset – see figure
, Aetiologies of Acquired and Congenital Neurogenic Palsies 2
• Herpes Zoster – virus affects dorsal root ganglion – any age –
treated with antiviral therapy
• Demyelination – age of presentation 20-40 years
• Inflammation – meningitis, Encephalitis, polio-myelitis, tertiary
syphilis, Tolosa-Hunt syndrome
o Tolosa-Hunt – inflammation in anterior part of cavernous
sinus
▪ All nerves (3, 4 and 6)
▪ Vision loss in ON involved
▪ Proptosis and sluggish pupil
▪ CT and ESR to diagnose – systemic steroids to treat
• Systemic lupus erythematosus – connective tissue and NS
affected – pain relief
• Sarcoidosis – granulomatous disease – isolated or multiple nerve
palsies sometimes with pain
• Guillain-Barre – post viral infections- greater in women and 20-50
years, sudden acute motor paresis – steroids, plasma exchange and
intravenous immunoglobulin treatment
• Miller Fisher – ophthalmoplegia – treatment as for Guillain-Barre
• Gradenigo’s – middle ear infection leading to petrositis affecting 6th
nerve
• AIDS – fungal or parasitic / neoplasms and vascular problems are
complications
Multiple cranial palsies
• Causes are neoplasms and trauma – less common include:
• Herpes zoster, aneurysm, Tolosa-Hunt, Miller-Fisher, Cavernous
sinus lesions, meningitis, Encephalitis
• 11% in children – multiple palsies
Congenital palsy
• 6th NP in under 14s found hydrocephalus, cerebral palsy and
inherited SO palsy and intoxications from mother as possible causes
Prognosis
• Recovery more likely when treatment of underlying cause
successful – Park et al. (2008)
• Regression common in tumours – spontaneous remission
Concomitant – angle of deviation same fixing either eye and in all positions of gaze
Incomitant – angle varies depending on fixing eye and direction of gaze
Incomitance is caused by:
• Neurogenic palsies
• Mechanical limitation
• Anisometropia
Neurogenic palsies
• Nerve supply to muscle is affected
• Can affect 1 muscle or group
• Consider observations and determine further investigations that may be required
• Recording findings as evidence of recovery, regression and stability
VA – normal though may be reduced in:
• Traumatic mydriasis
• Previous amblyope
• Related neurogenic conditions i.e. MS
• Recent reduction in VA can lead to decompensation of longstanding palsy
• Coincidental pathological cause
Things to consider:
• Deviation in primary position
• Fixing with unaffected eye – primary deviation
• Fixing with affected eye – secondary deviation
Figure 1 – A diagram showing the positions of each vertical muscle in both
• AHP to avoid deviation
eyes.
AHP
• Turn/tilt/elevation/depression
• Places eyes away from action of affected muscle
• On CT, record AHP, size and type of deviation
Observations during OM
• Smoothness of movements during smooth pursuits
• Head movements in child indicative of avoiding affected movement
• Pupils, lid position and changes
• Globe position and changes and nystagmus
• Versions, ductions and determine development of muscle sequelae
• BSV
• Normal or potential BSV most common – suppression/AC and diplopia ?
• Traumatic loss of fusion possible
• Measurements – c/s AHP/gls/N and D
• Investigate c Lees screens, uniocular field of vision and BSV field
,Muscle Sequelae, Diplopia Charts, and Interpretation of Hess Charts
Muscle sequelae – sequence of EOM adaptation following muscle weakness
• Sherrington’s – uniocular, innervation sent to muscle equivalent decrease innervation
sent to direct antagonist
• Hering’s – binocular, impulse to one muscle to contract, equal innervation sent to
contralateral synergist to contract
1. Primary u/a
2. Contralateral synergist o/a – Hering’s
3. Ipsilateral antagonist o/a – Sherrington’s
4. Secondary inhibition of contralateral antagonist – Hering’s
Factors affected muscle sequelae
• Above is expected pattern - develops overtime - primary u/a is largest
• Fixing eye could be affected or unaffected eye
• Takes time to develop, becomes more concomitant over time
• Primary deviation – fixing with unaffected eye
• Secondary deviation - fixing with affected eye
• Secondary deviation > primary – this differentiates between recently acquired and
longstanding
Diplopia charts
• Patient describes diplopia – red green goggles at 50 cm
• Drawn on chart – 9 positions of gaze
• Good for impaired OM and bilateral asymmetrical 4th nerve palsies
• Identify crossed and uncrossed
• Higher image from lower eye – lower image from higher eye
• Extorted eye sees intorted image – intorted eye sees extorted image
• Lines furthest away – greatest separation of diplopia
Hess charts – Lees screen
• Inner field 15 degrees and outer field tested at 30 degrees
• Position – higher field is higher eye, inward shifted is esodeviation
• PP deviation – cannot tell if tropia or phoria – 1* fixing unaffected 2* fixing affected
• Size of field – smaller = primary limitation in that eye
• u/a – inward displacement of dots – 1* u/a is largest displacement
• o/a – outward displacement of dots in direction of o/a contralateral synergist
• Mechanical – flat and narrow field – reversal in opposite pos. of gaze
• Equal sized field – symmetrical limitation and longstanding palsy = concomitance
• Sloping field – A and V pattern
• Hess charts are used in line with other tests and used as a way to compare changes in
recovery, regression and stability overtime
,Aetiologies of Acquired and Congenital Neurogenic Palsies 1
Aetiologies – causes of the palsy
• Interruption to neural supply
• Interruption to blood supply
o Small ischaemic attacks due to blockage or bleed – common in elderly as isolated palsies
o Recovery rate is high – 90% of 3rd NP by 6/12 according to Akagi et al. (2008)
o Risk factors – diabetes, arteriosclerosis and hypertension
o Patel et al. (2005) – diabetes risk factor for 6th NP – x6 increase w/ diabetes, x8 increase w/
diabetes and hypertension – hypertension alone = no increase
o Jacobson et al. (1994) – diabetes causes 5.75x increase in 3rd NP – left ventricular
hypertrophy cases 5.5x increase not caused by hypertension alone
o Cocaine – differential diagnosis for 3rd NP especially in young
o Giant cell arteritis – inflammation of blood vessels – 6-70% irreversible vision loss – med.
age is 75 years – Kawasaki and Purvin, (2009)
o Erythrocyte sedimentation rate – more than 50mm/h for 96% of patients – normal 0-30mm/h
o Signs – jaw claudication, head ache, weight loss, anorexia, fever, anaemia etc.
o Symptoms – vision loss, diplopia, eye pain, amaurosis fugax
o Ocular ischaemic lesion – ant. isch. optic neuropathy, cent. Retinal vein occl., cilioretinal
artery occl., post. isch. optic neuropathy
• Intracranial vascular abnormality
o Aneurysm – persistent localised dilations of a blood vessel wall – result of trauma, infection
and inflammation – symptoms due to pressure, bleeding and rupture
▪ Internal carotid and posterior communicating artery – 3rd NP
▪ Intracranial portion of internal carotid – compression of visual pathway
▪ Cavernous sinus – 3rd and 6th NP, isolated 6th NP w/ ipsilateral Horner syndrome
o AVM – congenital – arterial and venous circulation – problematic in 2nd and 3rd decades of
life – headaches – symptoms due to compression, haemorrhage, ischaemia and vascular
steel
o Fistula – abnormal connection between carotid artery and cavernous sinus
▪ Traumatic or spontaneous – high and low velocity – direct and dural – internal/ext.
▪ See diagram
▪ Trauma/vascular/tumour
▪ Tumours – 4th and 6th nerves commonly affected – 3rd NP post pituitary tumours
▪ Trauma – 4th NP susceptible to closed head trauma
▪ Idiopathic intracranial hypertension – more in females and obese – headache etc.
▪ Intracranial hypotension – following dural puncture , headache
▪ Diabetes – 3rd and 6th nerves most affected – pupil spared
o Pupil in 3rd NP – aneurysm compresses 3rd N → iris sphincter spared
o Aberrant regen. – occur 6+ weeks after onset – see figure
, Aetiologies of Acquired and Congenital Neurogenic Palsies 2
• Herpes Zoster – virus affects dorsal root ganglion – any age –
treated with antiviral therapy
• Demyelination – age of presentation 20-40 years
• Inflammation – meningitis, Encephalitis, polio-myelitis, tertiary
syphilis, Tolosa-Hunt syndrome
o Tolosa-Hunt – inflammation in anterior part of cavernous
sinus
▪ All nerves (3, 4 and 6)
▪ Vision loss in ON involved
▪ Proptosis and sluggish pupil
▪ CT and ESR to diagnose – systemic steroids to treat
• Systemic lupus erythematosus – connective tissue and NS
affected – pain relief
• Sarcoidosis – granulomatous disease – isolated or multiple nerve
palsies sometimes with pain
• Guillain-Barre – post viral infections- greater in women and 20-50
years, sudden acute motor paresis – steroids, plasma exchange and
intravenous immunoglobulin treatment
• Miller Fisher – ophthalmoplegia – treatment as for Guillain-Barre
• Gradenigo’s – middle ear infection leading to petrositis affecting 6th
nerve
• AIDS – fungal or parasitic / neoplasms and vascular problems are
complications
Multiple cranial palsies
• Causes are neoplasms and trauma – less common include:
• Herpes zoster, aneurysm, Tolosa-Hunt, Miller-Fisher, Cavernous
sinus lesions, meningitis, Encephalitis
• 11% in children – multiple palsies
Congenital palsy
• 6th NP in under 14s found hydrocephalus, cerebral palsy and
inherited SO palsy and intoxications from mother as possible causes
Prognosis
• Recovery more likely when treatment of underlying cause
successful – Park et al. (2008)
• Regression common in tumours – spontaneous remission
