Download Cerebellum and Basal Ganglia

Cerebellum and Basal Ganglia
David Roman Renner, MD
Suzanne Stensaas, PhD
2009 Kenya Curriculum
BG
CBLM
Courtesy of Stephen C. Voron, MD
BG
CBLM
Courtesy of Stephen C. Voron, MD
pyramidal cell
in the motor
homunculus
of the frontal
lobe
BG
CBLM
Courtesy of Stephen C. Voron, MD
corticospinal
tract
BG
CBLM
Courtesy of Stephen C. Voron, MD
BG
CBLM
decusation at
the pyramids
(spinomedullary
junction
Courtesy of Stephen C. Voron, MD
BG
thalamus:
AKA the
“gate keeper”
prevents
unwanted
movements
T
CBLM
Courtesy of Stephen C. Voron, MD
BASAL
GANGLIA
BG
consultant on
automatic
movements
T
CBLM
Courtesy of Stephen C. Voron, MD
provides
input into the
thalamus
Cerebellum:
consultant on
rapid
movements
BG
CBLM
Courtesy of Stephen C. Voron, MD
provides
input into the
thalamus
Basal Ganglia
Cerebellum
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resting tremor
postural instability
festination
rigidity
masked facies
bradykinesia
dyskinesia
torticollis
chorea
athetosis
hemiballismus
akathisia
intention tremor
dysmetria
dysdiadochokinesia
hypotonia
heal to shin
finger to nose
rebound
ataxic gait
titubation
nystagmus
dysmetric saccades
Basal ganglia lesions produce
contralateral signs.
Cerebellar lesions produce
ipsilateral signs.
Most movement disorders produced by
cerebellar and basal ganglia pathology
disappear during sleep.
Cerebellar and basal ganglia signs are
usually not present if the corticospinal tract
is damaged.
The cerebellum is the great comparator:
1. It compares cortical willful command
with muscle tension, joint position, &
tone (via ipsilateral spinocerebellar tracts)
2. Advises the cortex on how much,
how many, how fast
3. The motor cortex sends the revised
command down the corticospinal tract
The BASAL GANGLIA are the autopilot
for procedural movements.
The CEREBELLUM is the refiner of
finely controlled movements
(particularly of fingers).
COMPARISON OF MOTOR SYSTEMS
http://library.med.utah.edu/neurologicexam/html/home_exam.html
Lowe r Motor Neuron
Spina l Cord
Uppe r Motor Neuron
Corticospina l Tract
Cerebellum
Basal Ganglia
Efferent part of
monosynaptic reflex
Volunta ry movement
Muscle tone by
inhibiting antagonists
Maintains muscle
fibers (trophic factors)
Muscle tone
Rapid coordinated alternating
skilled movements that are
learned
Eye-head movements
Facilitates intentional
movements and inhib it
extraneous movements
Autopil ot for motor activities
Normal
Weakness or paralysis
Fine control, espec. finger
flexors
Inhibitory to Lower motor
neurons
Weakness or paralysis
Posture and Gait
Balance, equili brium,
orientation in space
timi ng, duration, and ampli tude
Voluntary movements in an
automatic manor.
Hyperreflexia
Hyperactive deep tendon
reflexes
Babins ki- extensor plantar
reflex
Spasticity
Trunca l ataxia, gait ataxia
Shuffling or festinating gait,
small steps, hard to turn
Nystagmus, Dizziness,
Masked facies, few bli nks
Decomposition of movement
Diffi culty turning or starting,
hypo kinetic = bradykinesia
Paucity of associated
movements
Abno rmal
Areflexia
Fasciculation
Muscle Atrophy
Flaccid paralysis
Dysmetria- ataxia of arms
Dysynergia
Dysdiadocho kinesia- inabili ty
to do rapid alternating
movements
Hypotonia- pendular reflexes
Intention tremor
Scanning speech
Chorea, athetosis,
hyperkinetic
Rigidity ( lead-pipe )
(cogwheel),
Resting tremor
Soft speech
Courtesy of Stephen C. Voron, MD