Lesson 32 - Upper and Lower motor neurons

What type of tetraparesis does IVDD cause?

upper motor neuron

What type of tetraparesis does acute non-compressive nucleus pulposus extrusion (ANNPE) cause?

upper motor neuron

What type of tetraparesis does fibrocartilagenous embolism cause?

upper motor neuron

What type of tetraparesis does diskospondylitis cause?

upper motor neuron

What type of tetraparesis does a tumor cause?

upper motor neuron

What type of tetraparesis does trauma cause?

upper motor neuron

What type of tetraparesis does tick paralysis cause?

lower motor neuron

What type of tetraparesis does botulism cause?

lower motor neuron

What type of tetraparesis does fulminant myasthenia gravis cause?

lower motor neuron

What type of tetraparesis does polyadiculoneuritis cause?

lower motor neuron

What type of tetraparesis does coral snake envenomation cause?

lower motor neuron

What type of tetraparesis does polymyositis cause?

lower motor neuron

What are the signs of upper motor neuron damage?

1. weakness or paralysis

2. spasticity

3. increased muscle tone

4. hyperreflexia

5. positive babinski sign

What are the signs of lower motor neuron damage?

1. weakness or paralysis

2. decreased or absent muscle tone

3. hyporeflexia

4. involuntary muscle twitches

5. muscle atrophy

Where is the origin for upper motor neuron?

brainstem and some cortex

What is the origin for lower motor neuron?

ventral horn of spinal cord and motor nuclei of brainstem

What is the function of upper motor neurons?

modulates and influences LMN activity

What is the function of lower motor neurons?

directly innervates muscles

What is the pathway for upper motor neurons?

descends through brainstem and spinal cord

What is the pathway for lower motor neurons?

sends axons out of the central nervous system via cranial or spinal nerve roots

What is neurology?

study of nervous system and its disorders

What is paresis?

partial loss of voluntary movement or weakness

What is paralysis?

complete loss of motor function

What is ataxia?

lack of muscle coordination

What is proprioception?

sense of body position and movement

What is hyperesthesia?

increased sensitivity to sensory stimuli

What is hypoesthesia?

decreased sensitivity to sensory stimuli

What is parathesia?

abnormal sensation

What is dysmetria?

inability to regulate the rate, range, and force of movement

What is hypermetria?

movements go beyond the intended goal

What is hypometria?

movement fall short of intended goal

How does hypermetria usually manifest?

overflexion

What is tonus?

sustained muscle tone (extension)

What is clonus?

alternating contraction and relaxation (convulsions)

What is myoclonus?

rhythmic contraction of a muscle or group of muscles

What is nociception?

pain perception

What is allodynia?

painful response to a nonpainful stimulus

What is the term for same side?

ipsilateral

What is the term for opposite sides?

contralateral

Where is the upper motor neuron cell body?

brainstem some in motor cortex

Where is the lower motor neuron cell body?

spinal cord

What are the motor systems?

1. extra-pyramidal system

2. pyramidal system

What is the major motor system in animals?

extra-pyramidal system

Where does the EPS system originate?

brainstem

What does the EPS system activate and inhibit?

LMN of limbs, trunk, neck

What does the EPS system control?

large muscle groups that cause animals to move, gait, posture

Which motor system has noticeable clinical signs?

EPS

Where does the PS system originate from?

cerebrum

What does the PS system do as it travels down?

crosses over in the brainstem

What does the PS system control?

fine muscles/small muscle groups

What motor system is important in primates?

PS

Which motor system usually as overlooked clinical signs?

PS

What motor system is involved with strokes?

pyramidal motor system

What are the signs of stroke?

palsy, holding arm weird

Which motor system is mostly ipsilateral?

EPS

Which motor system is contralateral?

PS

If there is a gain of function, what is causing those signs?

due to loss of inhibition or due to excitation or increased stimulation

If there is a loss of function, what is causing those signs?

due to destruction of functional tissue

Where is the pattern generator?

brainstem

What is the pattern generator important for?

gait

What are postural reactions?

fine motor control

What is tetra?

all four limbs

What is para?

pelvic limbs

What is hemi?

both limbs on same side of body

What is mono?

one limb affected

What is plegia mean?

paralysis

What motor neurons have muscle fasciculations?

lower motor neurons

What is the tonicity of LMN?

hypotonic, flaccid, soft

What is the tonicity of UMN?

normal or increased muscles are rigid, spastic

Why is there spastic muscle with UMN?

loss of the inhibitory input of UMN & LMN

What is seen on gait analysis of UMN?

1. increased tone/stiffness

2. delayed protraction

3. long floating strides

4. swinging out

5. crossing knuckling over

6. wide based over-reaching

What is seen on gait analysis of LMN?

1. paresis

2. small excursions

3. bunny hopping

What are the reflexes like for UMN?

normal to hyper

What are the reflexes like for LMN?

normal to hypo/absent

Where is intumescences seen with the spinal cord?

cervico-thoracic and lumb-sacral regions

What are the forms of ataxia?

1. proprioceptive

2. vestibular

3. cerebellar

What are signs of spinal cord dysfunction?

1. ataxia

2. proprioceptive deficits

3. paresis/paralysis

4. urinary/fecal incontinence

5. decreased or absent nociception

What does schiff sherrington signify?

severe spinal cord damage usually in thoraco-lumbar region

What happens to the forelimb in schiff sherrington?

rigid extension

What happens to the hindlimb in schiff sherrington?

paralysis