Neuroanatomy and neurological exams Flashcards
What is the definition of neurological disorders?
Diseases of the central and peripheral nervous system
What does the CNS consist of?
Brain and spinal cord (White and grey matter)
What is found within the forebrain?
Cerebral hemispheres, thalamus, hypothalamus, basal nucleuu
The brain stem comprises of:
Midbrain, Hindbrain, Cranial nerves III-XII
What is the function of the midbrain?
Ascending reticular activating system (consciousness), relays vision and hearing, relays motor function
What is the function of the hindbrain?
Cerebellum (coorderination), pons (relays information between cerebrum and cerebellum), medulla oblongata (respiration and cardiac function)
What does the PNS consist of?
Cranial and spinal nerves
What are afferent neurons stimulated by?
Mechanoreceptors (pressure)
Nociceptors (Chemical, heat, cold, mechanical deformation)
Proprioceptors (golgi tendon apparatus, muscle spindles, joints, tendons)
What is the neuroanatomy of motor neurons?
Effector neurons; muscle, glands
What is the neuroanatomy of lower motor neurons?
Somatic a-neuron-cell body in ventral portion of spinal tract
What is the neuroanatomy of upper motor neurons?
Located in brain (cortex, medulla, midbrain) - voluntary motor control
Initiate movement, maintain tone in extensor muscles
Calming effect on reflex arcs
What are signs of lesions on lower motor neurons?
Loss of spinal reflex, loss of voluntary control, atonia, flaccid paralysis, rapid muscle atrophy
What are signs of lesions on the upper motor neurons?
Loss of ‘calming effect’, loss of voluntary control, reflex intact and may be hyperactive, hypertonia, spastic paralysis
What are the goals of a neurological exam?
To locate affected anatomical area of damage/effect
To make a differential diagnosis list
Veterinary diagnosis to decide on treatment and prognosis
Physio diagnosis to evaluate progress
What are the 8 steps to a neurological exam?
History
Behaviour and mental state
Posture and position of body at rest
Gait evaluation
Cranial nerve assessment
Postural testing
Spinal reflexes, muscle evaluation
Sensory evaluation
Name things you may check when looking at the posture
Head tilt
Head turn
Spinal curvature (scoliosis, lordosis, kyphosis, torticollis)
Wide based stance
Define paresis
Some voluntary movement
Define paralysis (plegia)
Inability to move/weakness
What does the prefix ‘tetra’ mean?
Affects all four limbs (lesion cranial to T3)
What does the prefix ‘para’ mean?
Affects hind limbs (Caudal to T2)
What does the prefix ‘Mono’ mean?
One limb only, likely to be peripheral nerve damage
What does the prefix ‘hemi’ mean?
Affects both limbs on same side
Ataxia is loss of coordination of movement. What are the three types?
Proprioceptive (abnormal limb placement, limb paresis, weakness)
Vestibular (head tilt, rolling/falling to one side)
Cerebellar (Wide base stance, intention tremors)
Describe three ataxia gait effects
Hypermetria - longer protraction phase
Hypometria - shorter protraction phase
Dysmetria - uncoordinated irregular gait
What are signs of UMN paresis?
Delay in onset of protraction/initiating movement, longer and stiffer stride, ataxia often also present
What are signs of LMN paresis?
Difficulty weight bearing, shorter strides, chopping gait, bunny hoping, limb collapse, muscle tremors, ataxia absent
What are the 12 cranial nerves?
- Olfactory
- Optic
- Oculomotor
- Trochlear
- Trigeminal
- Abducens
- Facial
- Vestibulocochlear
- Glossopharyngeal
- Vagus
- Accessory
- Hypoglossal
Which cranial nerve(s) does the menace test check?
Optic
Facial
Which cranial nerve(s) does the pupillary light reflex check?
Optic
Occulomotor
Which cranial nerve(s) does the palpebral reflex check?
Trigeminal
Which cranial nerve(s) does the vestibulo-occular reflex check?
Vestibulo-cochlear
Trochlear
Abudcens
Which cranial nerve(s) does the Corneal sensation check?
Abducens
Trigeminal
Which cranial nerve(s) does the Nasal mucosa stimulation check?
Trigeminal
Which cranial nerve(s) does the lip pinch check?
Trigeminal
Which cranial nerve(s) does the gag reflex check?
Glossopharyngeal
Vagus
Accessory
Which cranial nerve(s) does the Slap test check?
Glossopharyngeal
Vagus
Accessory
Which cranial nerve(s) does the tongue pull check?
Hypoglossal
What is segmental testing for?
Aims to narrow down lesion locality in spinal cord
Either Cranial to T3 (C1-T2)
Caudual to T2 (T3 - S3)
PNS - nerve, nm junction, muscle
How do you check the thoracic limb?
Withdrawal reflex
Extensor carpi radialis reflex
Biceps branchii and triceps reflex
How do you check the pelvic limb?
Withdrawal reflex
Patellar reflex
Cranial tibial and gastrocnemius reflex
How do you check the tail and perineal region?
Perineal reflex
Define anaesthesia
Complete loss of sensation
Define hypoaesthesia
Reduced sensation
Define hyperasthesia
Increased sensation
Describe analgesia
Loss of pain sensation
Define hypoalgesia
Reduced pain sensation
Define hyperalgesia
Increased pain sensation
Define neuropraia
Temporary loss of function
Define axonotmesis
Damage to aon but not permanent
Define neurotmesis
Severance of axon
