0
Basal Ganglia
1. Neostriatum
Caudate nucleus
Putamen
Ventral striatum (nucleus accumbens)

2. Paleostriatum
Globus pallidu...
And claustrum

And substantia

innominata
Nucleus accumbens

Basal Ganglia
It is a number of nuclear (grey matter) masses ...
The lentiform nucleus is three- sided, having a convex lateral surface and 2 other
surfaces that converge to a medial apex...
2- Caudate nucleus:
It consists of a large head and body and a tapering, curved tail. The head of
the caudate is completel...
principal nuclei of the basal ganglia are (1) the striatum, (2) the globuspallidus (or pallidum),
substantianigra (consist...
The tail of the caudate
passes posteriorly and
follows the curvature of
the lateral ventricle then
descends into the
tempo...
3- Globus Pallidus:
It lies medial to putamen, separated from it by the lateral medullary lamina. Its
medial apex nestles ...
4- Substantia Innominata:
It refers to the basal part of the rostral forebrain that lies beneath the corpus striatum.
It c...
Forebrain

Midbrain
Circuit of the
basal ganglia
AFFERENT FIBERS
 Corticostriate fibers
all parts of the cerebral cortex send
axons to the caudate nucleus & putamen.
Each...




Thalamosriate fibers
The intralaminar nuclei of the thalamus
send large numbers of axons to the
caudate nucleus & pu...


Brainsten striatal fibers
ascending fibers from the brinstem
end in the caudate nucleus & putamen
& liberate serotonin ...




Striatopallidal fibers
these fibers pass from the caudate
nucleus & putamen to the globus pallidus.
They have gamma ...
AFFERENT FIBERS
 Striatopallidal fibers
these fibers pass from the caudate &
putamen to the globus pallidus. GABA as
thei...


1.
2.
3.
4.

Pallidofugal fibers
these fibers can be divided into groups:
Ansa lenticularis , which pass to the
thalami...


Direct pathway : cortex –(+) striatum – (-) pallidum
internum/subst. nigra – (-) thalamus – (+) cortex ( increases
the ...
Cerebral Cortex

Glutamate

Indirect
Pathway

Striatum

D2
GABA-enk

Globus
Pallidus
externa

Direct
Pathway

Thalamus

SN...
Cerebral Cortex

Corticospinal tract and
Corticobulbar projections

Brainstem and
Spinal Cord
Cerebral Cortex

Striatum
Glutamate

Brainstem and
Spinal Cord
Cerebral Cortex

Striatum
Glutamate

D1

D2

Dopamine

Substantai Nigra compacta

Brainstem and
Spinal Cord
Cerebral Cortex

Striatum
Glutamate

Glutamate

D1
GABA-dyn

DA

Direct
Pathway

Thalamus

SNc

GABA

Brainstem and
Spinal...
Cerebral Cortex

Glutamate

Striatum

D2
GABA-enk

Globus
Pallidus
externa

D1
GABA-dyn

Thalamus
DA

Subthalamic
Nucleus
...
Cerebral Cortex

Glutamate

Indirect
Pathway

Striatum

D2
GABA-enk

Globus
Pallidus
externa

Direct
Pathway

Thalamus

SN...
•

•

•

The corpus striatum regulates muscle tone &
thus help in smoothening voluntary
movements.
It controls automatic a...









These do not receive any sensory input from spinal cord
unlike the cerebellum. Basal ganglia contribute to
c...
1- Huntington’s Disease
It is an degenerative autosomal dominant inherited disease with the onset occurring in adult
life....
2- Parkinson’s disease
It is a neurodegenerative disease of elderly, of unknown cause. It is
characterized by akinesia, fl...
3- Sydenham’s

Chorea ( St Vitus’ dance )

The patient exhibits involuntary, quick,
jerky, spasmodic, irregular movements ...
Definition: Tracts other than corticospinal tract are
known as Extrapyramidal tract.
The word extrapyramidal is slowly bei...
1.
2.
A.
B.
C.
D.
E.

Basal Ganglia
Midbrain giving rise to following
bulbospinal tracts.
Rubrospinal tract.
Vestibulospin...






Includes all motor pathways not part of the pyramidal system
Upper motor neuron (UMN) originates in nuclei deep...




Reticulospinal tracts – originates at reticular formation
of brain; maintain balance
Rubrospinal tracts – originate...


All fibers that influence the motor activity
without passing through the pryamidal tract
› Cortex
› Basal Ganglia (caud...
Function

Dysfunction

1. Regulation and integration of
voluntary motor activity

Involuntary motor activity:
rhythmic & r...
Note:
1. UMN cell body location
2. UMN axon decussates in pons
3. Synapse between UMN and LMN
occurs in anterior horn of s...
Red Nucleus in Midbrain

Decussation at the level of red nucleus

Pass down through Pons & Medulla

Occupies the lat. Whit...
Afferent from cerebellum, vestibular apparatus
& vestibular nuclei

Spinal motor neuron

Innervating axial &
postural musc...
Superior & Inferior collicili in midbrain

Near Medial longitudinal fasiculus

Cervical spinal motor neuron of anterior ho...
The reticular formation makes up a central
core through much of the brainstem. It
contains many different nuclear groups.
...
It arises in the cells of inferior olive of the
medulla and is found only in the cervical
region of the spinal cord.
Funct...
Origin : vestibular nucleus, reticular
formation,
superior colliculus
Course : uncrossed fibers. Extend up to
upper cervic...



Akinetic rigid syndrome (Parkinsonism)
Dyskinesias
› Tremor
› Chorea
› Myocolonus
› Tics
› Dystonia



Tremors is a rhythmic, involuntary,
oscillatory movement of body parts
It is the most common movement
disorder.





Tremors are classified as rest or action
tremors.
Rest tremor occurs when the affected
body part is completely sup...




Is continuous flow of involuntary irregular
movement. The movements are rapid,
jerky, non rhythmic and explosive tha...


Causes
›
›
›
›
›
›
›

Hereditary: huntington’s disease
Birth injury: Kernicterus
Rheumatic: Sydenham’s chorea
Pregnancy...


repetitive involuntary, slow, sinuous, writhing
movements, which are especially severe in
the hands. There are also ele...


Involuntary, twisting, sustained
movement of the limb or head resulting
in an abnormal posture.


Brief, isolated, involuntary, random, jerk
movement of a group of muscles.
Intermittent with distinct pause between
eac...




Repetitive, stereotyped, semipurposeful
movement.
Patient could willingly suppress them at expense of
mounting inne...
Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)
Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)
Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)
Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)
Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)
Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)
Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)
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Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)

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basal ganglia has dominant role in movement control in our body. Thus this slide presents basic anatomy and related disorders.

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Transcript of "Basal ganglia and clinical anatomy, by Dr. Gagan Gupta(PT)"

  1. 1. Basal Ganglia 1. Neostriatum Caudate nucleus Putamen Ventral striatum (nucleus accumbens) 2. Paleostriatum Globus pallidus external segment (GPe) Globus pallidus internal segment (GPi) 3. Substantia Nigra Pars compacta (SNc) Pars reticulata (SNr) 4. Subthalamic nucleus (STN)
  2. 2. And claustrum And substantia innominata Nucleus accumbens Basal Ganglia It is a number of nuclear (grey matter) masses which lie within the cerebral hemisphere. They are corpus striatum; amygdaloid nucleus and claustrum. Its major components are caudate nucleus; putamen and globus pallidus . These structures are involved in the control of posture and movement. They are sometimes referred to anatomically as the corpus striatum but clinically, as basal ganglia. Notice that the function of amygdala is differ. Gross anatomically, the putamen and globus pallidus are called the lentiform or lenticular nucleus. The corpus striatum are connected with thalamus ; subthalamus of diencephalon and substantia nigra of midbrain.
  3. 3. The lentiform nucleus is three- sided, having a convex lateral surface and 2 other surfaces that converge to a medial apex which lies against the genu of the internal capsule. 1- Putamen: It lies lateral to the internal capsule and globus pallidus. It is separated from the globus pallidus by a thin lamina of nerve fibers ( the lateral medullary lamina ). Lateral to it lies a thin sheet of grey matter ( claustrum ) which separates the white matter into 2 layers, the external capsule and the extreme capsule. Lateral to the extreme capsule lies the cortex of the insula ( deep within the lateral fissure of the hemisphere ).
  4. 4. 2- Caudate nucleus: It consists of a large head and body and a tapering, curved tail. The head of the caudate is completely separated from the putamen by the internal capsule. Rostrally, it is continuous with the putamen at the anterior limb of the internal capsule. At this level, the most ventral portion of the striatum is the nucleus accumbens which is connected to the limbic system. The head of the caudate nucleus forms a prominent bulge in the lateral wall of the anterior horn of the lateral ventricle.
  5. 5. principal nuclei of the basal ganglia are (1) the striatum, (2) the globuspallidus (or pallidum), substantianigra (consisting of the pars reticulata and pars compacta), and (4) the subthalamic . The striatum consists of three important subdivisions: the caudate nucleus, the putamen, and striatum (which includes the nucleus accumbens). The striatum is divided into the caudate nu tamen by the internal capsule, a major collection of fibers that run between the neocortex an directions. Striatum = caudate+putamen
  6. 6. The tail of the caudate passes posteriorly and follows the curvature of the lateral ventricle then descends into the temporal lobe where it lies in the roof of the inferior horn of lateral ventricle.
  7. 7. 3- Globus Pallidus: It lies medial to putamen, separated from it by the lateral medullary lamina. Its medial apex nestles into the lateral concavity of the internal capsule. It consists of 2 division which are separated by a thin sheet of fibers ( the medial medullary lamina ). The medial segment is the smaller one. The putamen and globus pallidus ( lentiform nucleus ) lie lateral to the internal capsule and deep to the cortex of the insula.
  8. 8. 4- Substantia Innominata: It refers to the basal part of the rostral forebrain that lies beneath the corpus striatum. It contains several groups of neurons. One of them is the nucleus basalis that project to the cerebral cortex and utilize acetylcholine as their neurotransmitter. These neurons undergo degeneration in Alzheimer’s disease. 5- Claustrum: It is a thin plate of grey matter placed lateral to lentiform nucleus. Its anteroinferior part fuses with the anterior perforated substance and the
  9. 9. Forebrain Midbrain
  10. 10. Circuit of the basal ganglia
  11. 11. AFFERENT FIBERS  Corticostriate fibers all parts of the cerebral cortex send axons to the caudate nucleus & putamen. Each part of cerebral cortex projects to a specific of the caudate putamen complex. Most of the projections are from the cortex of the same side. The large input is from the sensory motor cortex. Glutamate is the neurotransmitter of the corticostriate fibers.
  12. 12.   Thalamosriate fibers The intralaminar nuclei of the thalamus send large numbers of axons to the caudate nucleus & putamen Nigrostriate fibers Neurons in the substantia nigra send axons to the caudate nucleus & putamen & liberate dopamine at their terminals as the neurotransmitter. It is believed that these fibers are inhibitory in function.
  13. 13.  Brainsten striatal fibers ascending fibers from the brinstem end in the caudate nucleus & putamen & liberate serotonin at their terminals as the neurotransmitter. It is thought that these fibers are inhibitory in function.
  14. 14.   Striatopallidal fibers these fibers pass from the caudate nucleus & putamen to the globus pallidus. They have gamma aminobutyric acid ( GABA ) as their neurotransmitter. Striatinigral fibers fibers pass from the caudate & putamen to the substntia nigra. Some of the fiber use GABA or acetylcholine as the neurotransmit ter,while other use substance P.
  15. 15. AFFERENT FIBERS  Striatopallidal fibers these fibers pass from the caudate & putamen to the globus pallidus. GABA as their neurotransmitter.
  16. 16.  1. 2. 3. 4. Pallidofugal fibers these fibers can be divided into groups: Ansa lenticularis , which pass to the thalamic nuclei Fasciculus lenticularis , which pass to the subthalamus pallidotegmental , fibers terminate in the caudal tegmentum of the midbrain pallidosubthalamic fibers , which pass to the subthalamic nuclei.
  17. 17.  Direct pathway : cortex –(+) striatum – (-) pallidum internum/subst. nigra – (-) thalamus – (+) cortex ( increases the activity of the thalamus and the excitation of cerebral cortex = increased motor activity)  Indirect pathway : cortex – (+) striatum –  (-) pallidum externum – (-) subthalamic nc. – (+) pallidum internum – (-)thalamus – (+) cortex (decreases activity of the thalamus and the excitation of cerebral cortex = decreased motor activity)
  18. 18. Cerebral Cortex Glutamate Indirect Pathway Striatum D2 GABA-enk Globus Pallidus externa Direct Pathway Thalamus SNc Glutamate Brainstem and Spinal Cord D1 GABA-dyn DA Subthalamic Nucleus Glutamate GABA Globus pallidus interna/Substantia Nigra reticulata
  19. 19. Cerebral Cortex Corticospinal tract and Corticobulbar projections Brainstem and Spinal Cord
  20. 20. Cerebral Cortex Striatum Glutamate Brainstem and Spinal Cord
  21. 21. Cerebral Cortex Striatum Glutamate D1 D2 Dopamine Substantai Nigra compacta Brainstem and Spinal Cord
  22. 22. Cerebral Cortex Striatum Glutamate Glutamate D1 GABA-dyn DA Direct Pathway Thalamus SNc GABA Brainstem and Spinal Cord Globus pallidus interna/Substantia Nigra reticulata
  23. 23. Cerebral Cortex Glutamate Striatum D2 GABA-enk Globus Pallidus externa D1 GABA-dyn Thalamus DA Subthalamic Nucleus SNc Glutamate Brainstem and Spinal Cord Glutamate GABA Gpi/SNr
  24. 24. Cerebral Cortex Glutamate Indirect Pathway Striatum D2 GABA-enk Globus Pallidus externa Direct Pathway Thalamus SNc Glutamate Brainstem and Spinal Cord D1 GABA-dyn DA Subthalamic Nucleus Glutamate GABA Globus pallidus interna/Substantia Nigra reticulata
  25. 25. • • • The corpus striatum regulates muscle tone & thus help in smoothening voluntary movements. It controls automatic associated movements, like the swinging of arms during waking. Similarly, it controls the coordinated movements of different parts of the body for emotional expression. It influences the precentral motor cortex which is supposed to control the extrapyramidal activities of the body
  26. 26.      These do not receive any sensory input from spinal cord unlike the cerebellum. Basal ganglia contribute to cognitive functions of brain. These help cortex in execution of learned patterns of movements subconsciously. Corpus striatum , cerebellum & motor areas of cerebrum jointly are responsible for planning , execution & control of movements. Corpus striatum & cerebellum without sending fibres to spinal cord modify the effect on spinal cord through projections to motor cortex & extra pyramidal fibres. Basal ganglia & cerebellum do not initiate movements but are able to adjust motor commands.
  27. 27. 1- Huntington’s Disease It is an degenerative autosomal dominant inherited disease with the onset occurring in adult life. Within the striatum, there is progressive ; particular attrition of the cells that project to the lateral segment of the globus pallidus ( indirect segment ). This leads to disinhibition of the lateral pallidal neurons and inhibition of subthalamic nucleus. Medial pallidal neurons , therefore ,become abnormally underactive and unwanted; involuntary movements.The following signs is present: 1- Choreiform movements first appear as involuntary movements of the extremities and twitching of the face (facial grimacing). Later, more muscle groups are involved so the patient becomes immobile and unable to speak or swallow. 2- Progressive dementia occurs with loss of memory and intellectual capacity There is degeneration of the GABA; P-secreting and acetylcholine-secreting.
  28. 28. 2- Parkinson’s disease It is a neurodegenerative disease of elderly, of unknown cause. It is characterized by akinesia, flexed posture, rigidity and a resting tremor. It is due to depletion of striatal dopamine levels. It is treated by levodopa which restores normal striatal function. When drug therapy fails, neurosurgical ablation or electrical stimulation of the subthalamic nucleu or medial segment of the globus pallidus can help the patient.
  29. 29. 3- Sydenham’s Chorea ( St Vitus’ dance ) The patient exhibits involuntary, quick, jerky, spasmodic, irregular movements that are nonrepetitive. Sudden movements of the head; trunk or limbs. It is a common manifestation of rheumatic fever. 4- Hepatolenticular degeneration (Wilson’s disease) It is an inherited disorder ( autosomal recessive ) of copper metabolism. 5- Hemiballism It is rare with choreiform movements of the limbs on one side of the body. It caused by a lesion of cerebrovascular origin of the contralateral subthalamic nucleus.
  30. 30. Definition: Tracts other than corticospinal tract are known as Extrapyramidal tract. The word extrapyramidal is slowly being replaced by Corticonuclear & corticobulbar tracts. The descending tracts of spinal cord oter than pyramidal tracts are known as extrapyramidal tracts.
  31. 31. 1. 2. A. B. C. D. E. Basal Ganglia Midbrain giving rise to following bulbospinal tracts. Rubrospinal tract. Vestibulospinal Tract. Reticulospinal Tract Tectspinal Tract. Olivospinal Tract.
  32. 32.      Includes all motor pathways not part of the pyramidal system Upper motor neuron (UMN) originates in nuclei deep in cerebrum (not in cerebral cortex) UMN does not pass through the pyramids! LMN is an anterior horn motor neuron This system includes › › › ›  Rubrospinal Vestibulospinal Reticulospinal Tectospinal tracts Regulate: › › › Axial muscles that maintain balance and posture Muscles controlling coarse movements of the proximal portions of limbs Head, neck, and eye movement
  33. 33.    Reticulospinal tracts – originates at reticular formation of brain; maintain balance Rubrospinal tracts – originate in ‘red nucleus’ of midbrain; control flexor muscles Tectospinal tracts - originate in superior colliculi and mediate head and eye movements towards visual targets (flash of light)
  34. 34.  All fibers that influence the motor activity without passing through the pryamidal tract › Cortex › Basal Ganglia (caudate, putamen, globus › › › › pallidus, Subthalamic nucleus and substantia nigra) Thalamus Cerebellum Red nucleus Reticular nucleus
  35. 35. Function Dysfunction 1. Regulation and integration of voluntary motor activity Involuntary motor activity: rhythmic & regular (static tremor) Dysrhythmic and irregular (chorea, athetosis, dystonia) 2. Regulation and maintenance of muscle tone Hypertonia or rigidity 3. Regulation and maintenance of Bradykinesia, mask face, emotional & associative movement infrequent blinking, loss of swinging during walking.
  36. 36. Note: 1. UMN cell body location 2. UMN axon decussates in pons 3. Synapse between UMN and LMN occurs in anterior horn of sc 3. LMN exits via ventral root 4. LMN axon stimulates skeletal muscle
  37. 37. Red Nucleus in Midbrain Decussation at the level of red nucleus Pass down through Pons & Medulla Occupies the lat. White column of spinal cord Ends in ant. Horn of spinal cord Functions: Facilitatory influence on flexor muscle tone
  38. 38. Afferent from cerebellum, vestibular apparatus & vestibular nuclei Spinal motor neuron Innervating axial & postural muscles Function : Controls reflexes eg. Postural & righting Control eye movements.
  39. 39. Superior & Inferior collicili in midbrain Near Medial longitudinal fasiculus Cervical spinal motor neuron of anterior horn Function: Allow turning of the head in response to visual or Auditory stimuli.
  40. 40. The reticular formation makes up a central core through much of the brainstem. It contains many different nuclear groups. Pontine and medullary nuclei projects to the anterior horn of the spinal cord. It extend up to thoracic segments. Functions: Coordination of voluntary & reflex movement and is also responsible for the muscle tone. Control of respiration & diameter of blood vessels.
  41. 41. It arises in the cells of inferior olive of the medulla and is found only in the cervical region of the spinal cord. Functions : are not known clearly. It is believed that this tracts is involved in reflex movements arising from the proprioceptors.
  42. 42. Origin : vestibular nucleus, reticular formation, superior colliculus Course : uncrossed fibers. Extend up to upper cervical segments Function : coordination of reflex ocular movements , Integration of movements of eye & neck
  43. 43.   Akinetic rigid syndrome (Parkinsonism) Dyskinesias › Tremor › Chorea › Myocolonus › Tics › Dystonia
  44. 44.   Tremors is a rhythmic, involuntary, oscillatory movement of body parts It is the most common movement disorder.
  45. 45.    Tremors are classified as rest or action tremors. Rest tremor occurs when the affected body part is completely supported against gravity. Action tremors are produced by voluntary muscle contraction. › postural, isometric, kinetic tremors.
  46. 46.   Is continuous flow of involuntary irregular movement. The movements are rapid, jerky, non rhythmic and explosive that flit from portion of the body to another in random sequence. It affects limbs and face and caused by lesion in caudate nucleus
  47. 47.  Causes › › › › › › › Hereditary: huntington’s disease Birth injury: Kernicterus Rheumatic: Sydenham’s chorea Pregnancy: chorea gravidarum Vasculitic Thyrotoxicosis Drugs: L-Dopa
  48. 48.  repetitive involuntary, slow, sinuous, writhing movements, which are especially severe in the hands. There are also elements of postural disturbance. Usually combined with chorea known as chorea-athetosis
  49. 49.  Involuntary, twisting, sustained movement of the limb or head resulting in an abnormal posture.
  50. 50.  Brief, isolated, involuntary, random, jerk movement of a group of muscles. Intermittent with distinct pause between each movement.
  51. 51.    Repetitive, stereotyped, semipurposeful movement. Patient could willingly suppress them at expense of mounting inner tension There are 2 types of tics › Simple tics of children: transient or chronic › Complex tics: Gilles de La Tourette syndrome (tics, vocalization, obsessive behavior)
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