U5 O1 - Neurological and Ophthalmic Emergencies Flashcards
What is ataxia?
Incoordination of the limbs that can cause swaying,
abnormal carriage of limb(s) etc
What is blepharospasm?
Rapid blinking of the eyelids often in response to ocular pain or irritation.
What is clonus?
Involuntary, regular rhythmic contractions and relaxation of muscles
What is hemiparesis?
Weakness of 2 limbs on the same side.
What is horners syndrome?
Drooping of the eyelid (ptosis), constriction of the pupil
myosis/miosis) and retraction of the eyeball into the socket (enophthalmos
What is Hyphaemia?
Blood in the anterior chamber of the eye
What is Hypopyon?
Pus in the anterior chamber of the eye
What is nystagmus?
Abnormal movement of the eyes in synchrony. There is
usually a slow phase in one direction; and then a fast phase as the eyes flick back to their origin. It may be horizontal, vertical or rotational and it may only occur when the head position is altered (positional nystagmus).
What is Opisthotonus?
Strong contraction of the extensor muscles of the neck and back. This results in arching of the back; and
hyperextension (backward arching) of the head and neck - often with extension of the fore limbs.
What is paralysis?
Loss of motor (muscle) function. Generally used in
reference to a limb but could also be e.g. facial paralysis
What is paresis?
Partial loss of motor (muscle) function. Usually used in
reference to a limb but can also be used in relation to other parts of the body such as the eye
What is proprioception?
The sensory function which allows the animal to be aware of and adopt the normal limb positioning
What is Schiff-Sherrington posture ?
Increased forelimb extensor tone secondary to a serious injury from T3-L3
What is Spasticity?
An increase in the tone/activity of the extensor muscles of limb(s) leading to rigid paralysis: hypertonia
What is a spinal reflex?
Automatic response to a particular stimulus which involves spinal cord nerve pathways. Examples include the patellar reflex, cutaneous trunci reflex and perineal reflex.
What is strabismus?
A squint where both or one eye deviates from the normal position: usually ventrally and medially.
What is syncope?
A collapse/faint
What is tetraparesis?
Partial loss of motor (muscle) function in all 4 limbs.
What is tonus?
Increased extensor tone of muscles
The initial emergency neurological assessment involves assessing what three basic features?
The initial emergency neurological assessment involves assessing three basic features to try and quickly identify the severity and location of the neurological problem. It does not replace a full neurological assessment but can provide valuable
early information to allow emergency treatment to be provided without wasting valuable time. The three features to assess are:
1) Mental status
2) Ambulation
3) Cranial and spinal nerve function
An initial hands- off assessment is important. Visual assessment of level of consciousness and abnormalities is important e.g. nystagmus, miosis, balance issues etc. It is Important to remember that mental status is also affected by cerebral
perfusion so anything that interferes with this could affect the patient’s mental status.
How do you assess the mental status in an initial neurological assessment?
Mental status
This is an assessment of the patient’s level of alertness and can be tested in a number of ways. Hands off observation of the patient is very important - initially a
clinical assessment of the degree of consciousness of the patient should be made i.e. is it alert/awake. This can progress on to an assessment of the response to
external stimuli: such as a loud noise; or light; or the response to touch/noxious stimuli. Response to touch around the head, especially around the nose, medial
canthus of the eye and the ears, is particularly important to assess mental status,
How do you assess the ambulation in an initial neurological assessment?
Ambulation
This is the assessment of the animal’s ability to walk and move normally. If affected, an assessment of the degree of ataxia should be made. If limb function is reduced or impaired, is this localised to one limb, one side, or does it involve all four limbs?
In addition, some postural reactions, including basic proprioception tests, can be performed by knuckling over the paws in turn to see if the patient immediately
replaces the foot to its normal position. Any delay or failure to reposition the foot indicates a loss of sensory and / or motor nerve function to that limb.
Noxious stimuli are useful to test pain pathways and deep nerve function. These are classically performed by applying haemostats across the nail bed of the patient. The response should be vocalisation and / or movement of the head around to the side affected. Lack of response or reduced response suggests reduced function or lack of deep pain sensation which has a poor prognosis. This assessment should not be
performed if a patient has normal limb motor function. Due to the potential to cause pain, deep pain assessment should only be performed on veterinary direction.
How do you assess the mental status in an initial neurological assessment?
Cranial nerves
A full cranial nerve assessment is unlikely to be performed as part of the initial assessment – however an initial brief assessment of cranial nerve abnormalities can be helpful e.g. balance issues might indicate an issue with CN VIII, the vestibulocochlear nerve, or the cerebellum.
The following cranial nerves can be tested to help locate the source of a neurological
problem involving the head and neck:
Cranial nerve II optic nerve
Cranial nerve III oculomotor nerve
Cranial nerve IV trochlear nerve
Cranial nerve VI abducens nerve
Cranial nerve VII facial nerve
Cranial nerve VIII vestibulocochlear nerve
Cranial nerve IX glossopharyngeal nerve
Cranial nerve X vagus nerve
Cranial nerve XII hypoglossal nerve
Cranial nerve II and cranial nerve VII can be tested by assessing the menace response reflex i.e. does the patient blink when an object is moved rapidly towards them? Cranial nerve II travels directly from the back of the globe, through the calvarium and to the vision centre in the forebrain, close to the midbrain. On the
ventral brain there is some crossing over of the left and right optic nerves at the optic chiasma: so part of the left optic nerve crosses over to the right side of the brain and vice versa. The sensory nervous impulses are analysed in the vision centre: resulting in motor nerve impulses being transmitted in cranial nerve VII to the eyelids to cause blinking. An abnormal response can indicate damage or disease of the retina, cranial
nerve II, the vision centre of the forebrain or cranial nerve VII.
What following cranial nerves can be tested to help locate the source of a neurological problem involving the head and neck?
The following cranial nerves can be tested to help locate the source of a neurological problem involving the head and neck:
Cranial nerve II optic nerve
Cranial nerve III oculomotor nerve
Cranial nerve IV trochlear nerve
Cranial nerve VI abducens nerve
Cranial nerve VII facial nerve
Cranial nerve VIII vestibulocochlear nerve
Cranial nerve IX glossopharyngeal nerve
Cranial nerve X vagus nerve
Cranial nerve XII hypoglossal nerve