Neuro Flashcards
What is optic neuritis?
Optic neuritis is the most common presentation of multiple sclerosis.
It involves demyelination of the optic nerve.
What is a central scotoma?
A central scotoma is an enlarged central blind spot.
It is a key feature of optic neuritis.
What disease is characterized by pain with eye movement, impaired colour vision, RAPD and a central scotoma
optic neuritis.
What does a relative afferent pupillary defect indicate?
A relative afferent pupillary defect indicates a problem with the optic nerve.
It is assessed using the swinging flashlight test. The affected eye constricts more when shining a light in the other eye than the affected eye. There is a reduced pupil responsive to shining light in the eye affected
Causes of optic neuritis
MS
SARCOID
SLE
SYPHILIS
MEASLES/ MUMPS
NEUROMYELITIS OPTICA
LYME DISEASE
What cranial nerves are affected by lesions that cause double vision and nystagmus?
Oculomotor (CN III), trochlear (CN IV), and abducens (CN VI)
These nerves are responsible for controlling eye movements.
What does oscillopsia refer to?
The visual sensation of the environment moving and being unable to create a stable image
Oscillopsia can be distressing and is often associated with vestibular disorders.
What condition is caused by a lesion in the medial longitudinal fasciculus?
Internuclear ophthalmoplegia
This condition affects the coordination of eye movements.
What do the nerve fibres of the medial longitudinal fasciculus connect?
Cranial nerve nuclei that control eye movements
Specifically, the 3rd, 4th, and 6th cranial nerve nuclei.
What is the effect of a lesion in the medial longitudinal fasciculus on eye movement?
Impaired adduction on the same side as the lesion and nystagmus in the contralateral abducting eye
This results in the affected eye’s inability to move towards the nose during adduction.
What type of disorder does a lesion in the abducens (CN VI) cause?
Conjugate lateral gaze disorder
This disorder affects the ability of both eyes to move together laterally.
When looking laterally in the direction of the affected eye due to an abducens lesion, what happens to the affected eye?
The affected eye will not be able to abduct
For example, in a left abducens lesion, the left eye will not move left.
True or False: In a left abducens lesion, when looking to the left, the right eye will abduct.
False
The right eye will adduct instead.
Fill in the blank: The term ‘conjugate’ in conjugate lateral gaze means _______.
Connected
This indicates that both eyes are supposed to move together.
What are some examples of focal weakness in multiple sclerosis?
- Incontinence
- Horner syndrome
- Facial nerve palsy
- Limb paralysis
These symptoms indicate focal neurological deficits associated with multiple sclerosis.
What are some examples of focal sensory symptoms in multiple sclerosis?
- Trigeminal neuralgia
- Numbness
- Paraesthesia (pins and needles)
- Lhermittes sign
These symptoms reflect sensory disturbances that can occur in multiple sclerosis.