Chapter 7 Flashcards
What are the two methods of testing function?
Nerve conduction study (NCS)
Somatosensory evoked potentials (SEP)
What does NCS measure?
peripheral nerve function
What does SEP measure?
peripheral nerves and central nervous system pathways
What is compared to determine if NCS is normal?
distal latency
amplitude of the evoked potential
conduction velocity
What are SEPs used to determine?
verify subtle signs and locate lesions of the dorsal roots, posterior columns, and brainstem.
What is ataxia?
incoordination that is not due to weakness
What are three types of ataxia?
sensory
vestibular
cerebellar
What is the Romberg test used for?
to distinguish between cerebellar ataxia and sensory ataxia
What is neuropathy?
general term for dysfunction or the pathologic condition of one or more peripheral nerves
What is the sensory loss in peripheral nerve lesions?
- conscious proprioception and discriminative touch
- Cold
- Fast pain
- Heat
- Slow pain
What are the common causes of dysfunction of the spinal region?
trauma
disease
virus
What happens with complete transection of cord?
All sensation is prevented at one or two levels below the lesion
Voluntary motor control below the lesion is also lost
What happens with hemisection of the spinal cord?
- complete loss of sensation in contralateral side 2-3 levels below lesion
- discriminative touch and conscious proprioception lost ipsilateral to lesion
Lesion in posterior column:
conscious proprioception, 2 point discrimination and vibration lost below level of lesion
-ataxic movements
Brainstem region lesion:
mix of ipsilateral and contralateral signs
-sensory loss can be contralateral in upper midbrain after discriminative sensation have crossed midline
Somatosensory Cortex Lesion:
Conscious proprioception
Two-point discrimination
Stereognosis
Localization of touch and pinprick (nociceptive) stimuli
-contralateral and decrease of above sensations