Neuro Week 7: Cerebelluum, Basal Ganglia
Guillian Barre syndrome
dymleination occurs bcs immune system generates antibodies against Schwann cells
Wilsons disease (Basal Ganglia disorder)
excesive copper in basal ganglia - also in liver, brain & eyes
slow twitch muscle fibers (alpha motor neurons)
smaller alpha neurons involved in posture
how to test Diadochokinesis
supination/pronation
What do alpha neurons supply?
skeletal muscles
what is the innervation ratio of motor units
# of fibers innervated by a motor unit
What is the Functional organization of Cerebellum? (3 regions )
1. Vestibulocerebellum 2. Spinocerebellum 3. Neocerebellum * ipsilateral organization (left hemisphere controls left side of body)
Types of lower motor neurons
1. alpha motor neurons - BIG (alpha) cell bodies & myleinated axons 2. gamma motor neurons - med mylelinated hoes
What are the characteristics of the neuromuscular junction?
1. endplate: excitable region that intiates AP 2. obligatory response : ACHs always released after depolarization to help maintain muscle tone
Spinal tumors types
1. extradural : outside of dura matter 2.intradural: inside dura matter
what is affected in lower motor neuron lesions
1. muscle strength 2. muscle bulk 3. muscle contraction 4. muscle tone 5. muscle stiffness 6. reflexes
myotomes
10 muscle groups tested to determine motor level of patient - 0-5 ( 5 is Fully active)
Cerebral palsy- athetoid
Basal ganglia affected - jerky, abrupt, irregular -athetoid (slow, writhing) movements)
treatment for CP- athetoid
CIMT: cast, sling splint, forced to use affected UE
Gray matter of the spinal cord
Cell bodies H shape , 3 horns 1. dorsal horn: sensory 2. ventral horn: motor 3. lateral horn: sympathetic
Cerebellar signs
DANISH Dysmetria/Dyssnergia Diadochokinesis Ataxia Astasia Abasia Nystagmus Intentional Tremors Slurred/ Scanning Speech Hypotonia
What is the finger-to-nose exam testing for? (Cerebellar signs)
Dysmetria/dysenergy - trouble controlling distance
Diadochokinesis
Inability to perform rapidly alternating movement
Poliomyelitis
a viral infection - gray matter attacked
Quadriplegia
affectation of all 4 limbs
hemiplegia
affectation of one side
motor unit consist of
alpha motor neuron and muscle fiber it innervates
myasthenia gravis
autoimmune condition affecting synapes results in fewer receptos
White matter of Spinal cord
axons 1. dorsal column 2. lateral columns 3. anterior columns
Astasia-abasia
can't stand or can't maintain against gravity
where are Upper motor neurons
cell bodies are in hgier regions of brain - synapse on lower hoes
where are Lower motor neurons
cell bodies in spinal cord/ brain stem -innervate skeletal muscle fibers
Herniated disc (spinal cord injury)
common displacement of disc in lumbar or cervical -> Compresses nerve: numbness, pain
paralysis
complete loss of voluntary movement
Function of Vestibulocerebellum?
control balance and coordinate eye-body movements
Syringomyelia
cyst/cavity formation within spinal cord - cape like distribution
hypotonia
decreased muscle tone - pendular reflex
Parkinsons disease
degenerative condition where muscle tone increases - mask fask (no automatic expressions) - freezing of gait -resting tremors
Function of Spinocerebellum
gait and balance - sensory info f
Duchenne muscular dystrophy
genetic condition of X chromosome - onset @ 5 - progressive weakness of legs and pelvis
What are the components that make up the Basal Ganglia?
has an excitatory and inhibitory pathway, imbalnce = defect
Huntingtons disease (Basal Ganglia disorder)
hereditary neurodegenrative disease - graual onset, death after 10 yrs - rigiig, jerky movements, gait & balance issues - person becomes irritable (video we watched in class)
Hyper-reflexia
hyper reflex response - tapping patellar tendon can casuse limb to react 8x
rebound phenomenon
in Ataxia - remove resistance you get flinging movement (pt can hit themself)
when does muscle tone generally increase?
in upper motor neuron injuries
how to compensate Astasia-abasia
increase base of support (stand wider)
dermatomes
key sensory points that are labeled to determin sensory levels
Ataxia
lack of coordination w/ voluntary movement
fast twich muscle fibers
large alpha motor neurons involved w quick contraction for muscles
Cerebellum
little brain - controls coordination muscle tone, motor learning, fine motor tasks
What happens in Syringomyelia
may cause segmental or longitudial signs
how is the innervation ratio determined?
more fibers innnervated for big less skilled movements - less fibers for skilled movement (eye)
signs of Guillian Barre syndrome
muscle paralysis , deep pain, can't chew, swallow, speak
What do gamma motor neurons supply?
muscle spindles
Amyotrophic lateral sclerosis (ALS)
neuropathic disease destroying motor neurons - paresis , stiffness, twitches , - loss of cranial nerves = breathing,swallowing, speaking hard
paraplegia
paralysis in trunk, legs, and pelvic
Paresis
partial loss of voluntary contraction
What happens after SCI
pt enters spinal shock - bowel and bladder ( atonic or flaccid - spasticity
post-polio
reactivation of polio virus - happens 15-30 yrs after = pain, fatigue
Wilson's disease symptoms
rigidity, resting tremors, weakness, liver function lost, - brown ring in eyes
function of neocerebellum
sensory coordination of distal limb movements - involved w cognitino
basal ganglia function ( in relation to movement)
sequence motor steps (writing), action selection, intiation/control of movement
Spinal cord injuries
severe damage to the spinal cord that impairs the function of the spinal cord
intentional tremors
tremors at the end of movement - absent @ rest
neuromusccular junction
where motor axons synapse with muscle fibers
implications of SCI (summary)
•Upper motor neuron symptoms -Paralysis/paresis -Hyperreflexia below level of injury, areflexia at level of injury -Hypertonicity: •Spasticity - hyperactive response to quick stretch •Clonus repeated stretch reflex with passive dorsiflexion of foot -Muscle stiffness/shortening/contracture •Impaired sensation •Autonomic Dysreflexia •Pressure ulcers •Sexuality issues •Bowel and bladder issues •Psychosocial implications