convergence paralysis Flashcards
what is convergence parlaysis
Inability to converge
Although some convergence possible in paresis
C/o crossed diplopia at middle to near
Exotropia at near
May have involvement of accommodation and pupils
what is the ateiology of convergence paralysis
Head trauma
Neurological disease
Encephalitis
Multiple sclerosis
May be associated with dorsal midbrain syndrome – Parinaud’s syndrome (Feroze and Bhimji 2017)
Primary
Functional
Test BO fusional amplitude in distance
what is the management for convergence paralysis
Investigations
Base in prisms
Occlusion
Convex/hypermetropic lens if accomm affected
Referral for psychological/psychiatric assessment
what is convergence spasm
Usually spasm of near reflex
Contraction of medial recti muscles
Contraction of ciliary muscles
c/o uncrossed diplopia
c/o blurred vision if accomm spasm
what are features of convergence spasm
Esotropia
Could be variable in size
Miosis
Observe throughout testing
Consistency of convergence spasm and miosis
Spasm on lateral gaze gives appearance of LR palsy
Test abduction – doll’s head
Macropsia
Pseudomyopia
what is the ateiology of convergence spasm
Head injury (most common cause spasm near reflex Hyndman 2018)
Functional (aka psychogenic)
stress and anxiety
observation/ dynamic ret if accomm spasm too
Neurological disease
Encephalitis
Multiple sclerosis
Arnold Chiari malformation
Tumours (posterior fossa, pituitary)
Cerebral aneurysm (Weber et al 2008)
Following CI exercises
how to manage convergence spasm
Avoid treatment
Botulinum toxin (Kaczmarek et al, 2009)
Single or repeated injections
Limited success, but some find it helpful
Occlusion
Atropine with convex lenses
Refer for psychological/psychiatric assessment
Refer for neurological investigation if needed
what is an example case of convergence spasm
45y/o head trauma during RTA
Diplopia and blurred vision
Up to 45PD BO at near, orthophoric in dist
Conv spasm
Atropine and readers - disliked
BT to MR – short lasting exo – disliked
Pt keen on Sx but little evidence on success
Advice and other options?
what are some management options for convergence paralysis
Cyclo induces the need to converge to focus – use miotics which increase depth of focus and reduce drive to convergence
Pt is driving the spasm – reassure + learn to stop
’functional’ - up-front with patients/parents in an understanding, non-confrontational way – revealed underlying sig family event prior to symptoms
CBT (cognitive behaviour therapy)/Clinical psychologist
The patient reports accommodation to a level much worse than that expected for their age. How can you be sure that this is genuine?
One approach is to use objective testing methods to measure the patient’s accommodation. For example, an autorefractor or aberrometer can be used to measure the patient’s refractive error and accommodation response simultaneously. This can provide an objective measure of the patient’s accommodation, which can be compared to the expected level for their age.
Another approach is to perform additional tests to assess the patient’s binocular vision and accommodative function. These tests might include the cover test, prism bar test, and accommodative amplitude testing. These tests can help to identify any underlying binocular vision or accommodative issues that could be contributing to the patient’s complaints.
Convergence/accommodative spasm and 6th NP have an esotropia and limited abduction. How would you differentiate between the two?
Convergence/accommodative spasm and 6th nerve palsy can both cause esotropia and limited abduction, but there are several key differences between these two conditions that can help to differentiate them.
Convergence/accommodative spasm is a condition in which the patient’s accommodative and convergence systems are overactive. This can cause the eyes to turn inward (esotropia) and limit their ability to move outward (abduction). In this condition, the patient may experience symptoms such as headaches, eyestrain, and blurred vision when looking at near objects.
On the other hand, 6th nerve palsy is a neurological condition in which the 6th cranial nerve, which controls the lateral rectus muscle that abducts the eye, is damaged or not functioning properly. This can also cause an esotropia and limit abduction, but typically only affects one eye. In this condition, the patient may experience double vision, and the degree of esotropia may increase when they try to look in the direction of the affected eye.
To differentiate between these two conditions, a thorough eye examination is necessary. In the case of convergence/accommodative spasm, the patient may have a normal or near-normal range of eye movements in other directions, and may have a more noticeable esotropia when looking at near objects. In contrast, in the case of 6th nerve palsy, there may be limitations in abduction in the affected eye, and a more pronounced esotropia when looking in the direction of the affected eye.
What is the Holmes Adie pupil? And how is this differentially diagnosed from accommodative anomalies?
Holmes Adie pupil, also known as Adie’s tonic pupil, is a neurological disorder that affects the function of the pupil, causing it to be abnormally dilated and to react slowly or incompletely to light. This condition is usually caused by damage to the ciliary ganglion, which is part of the autonomic nervous system that controls the size of the pupil and the accommodation response of the eye.
Accommodative anomalies, on the other hand, refer to a range of conditions that affect the ability of the eye to focus on near objects. These can include convergence insufficiency, accommodative spasm, and other conditions that affect the function of the ciliary muscle and the accommodative system of the eye.
The key difference between Holmes Adie pupil and accommodative anomalies is the underlying cause of the condition. Holmes Adie pupil is a neurological disorder that is caused by damage to the ciliary ganglion, while accommodative anomalies are typically caused by dysfunction of the ciliary muscle or the accommodative system of the eye.
To differentiate between these two conditions, a thorough eye examination is necessary. In the case of Holmes Adie pupil, the pupil will be abnormally dilated and will react slowly or incompletely to light. The accommodation response of the eye may also be affected, but this will typically be less pronounced than the pupil abnormalities.
In contrast, in the case of accommodative anomalies, the pupil size and response to light will be normal, but the patient will experience difficulty focusing on near objects. Additional testing, such as measurement of the near point of convergence and assessment of accommodative function, can help to identify the specific
