Explanation of basal Ganglia and effects of lesion

1. Dr.Omer Tagelsir Abdalla

2.  It is a term given to a collection
of gray mater inside each
cerebral hemisphere.

3.  Putamen
 Globus pallidus
 Caudate nucleus
 Claustrum
 Subthalamic nucleus
 Subsatntia nigra

5. Lentiform nucleus
Thalamus
Caudate nucleus
Amigdala

11.  Caudate nucleus + Putamen = striatum OR
NEO STRIATUM
 PALEOSTRIATUM = GLOBUS PALLIDUS)
 ARCHISTRIARUM = AMYGDALOID BODY

12. Globus pallidus
Lentiform nucleus
Putamen
Caudate nucleus
Striatum

13.  It is situated lateral to the thalamus and is
divided by the internal capsule into:-
• Caudate nucleus.
• Lentiform nucleus.

16.  It is a large C-shaped mass of grey matter. It is
related to the lateral ventricle and thalamus
(medially), Internal capsule and lentiform
nucleus (laterally).
 It is divided into:
1. head.
2. Body.
3. Tail.

17. Body
Tail of caudate nucleus
Head of caudate nucleus
Amigdala

21.  It is a wedge-shaped mass of
grey matter.
 Its base is directed laterally ,
while its apex is directed
medially.
 It is related medially to the
internal capsule and laterally
to the external capsule.
 It is divided by vertical bands
of white matter into:-
A. Putamen: which is the larger,
darker, lateral part.
B. Globus pallidus: which is the
smaller, lighter, medial part.

22.  It is divided by vertical bands
of white matter into:-
A. Putamen: which is the larger,
darker, lateral part.
B. Globus pallidus: which is the
smaller, lighter, medial part.

23. Lentiform nucleus
Thalamus
Caudate nucleus
Amigdala

26.  it is a thin plate of
gray matter which is
separated medially
from the lentiform
nucleus by the
external capsule
and related laterally
to the insula.

29.  It is a small almond-shaped mass of
grey matter that continuous with the
tail of the caudate nucleus.
 It lies in the roof of the inferior horn of
the lateral ventricle close to the uncus.
 It is considered as a part of the limbic
system.

33.  Cortex projections to corpus striatum
 Informing the basal ganglia what is going in the
cortex
 Return by way of thalamus to cortex

41.  Input
 All areas of cortex
 Substantia nigra
 Intralaminar nuclei of thalamus

42.  Output
 Mainly to thalamus through globus
pallidus
 Efferents from caudate nucl. Ends in
prefrontal area
 Efferents from putamen ends in motor
area
 To Substantia nigra

43.  Input
 From striatum and subthalamic nucl.
 Output
 To subthalamic nucl.
 to thalamus to end in the motor
cortex

45.  Input
 Striatum
 subthalamic nucleus
 Output
 Thalamus to motor area
 Caudate nucl. & putamen

47. Striatum
CORTEX
GB
SN
Thal
amu
s
CORTICO-STRIATO-
PALLIDO-THALAMO-
CORTICAL
CORTICO-STRIATO-
NIGRO-THALAMO-
CORTICAL

50.  Cooperate with the cerebral cortex in controlling
movements
 Receive input from many cortical areas
 Evidence shows that they:
 Start, stop, and regulate intensity of voluntary
movements
 In some way estimate the passage of time

51. SYDENHAM’S CHOREA
- Complication of
Rheumatic Fever
- Fine, disorganized , and
random movements of
extremities, face and
tongue
- Accompanied by
Muscular Hypotonia
- Typical exaggeration of
associated movements
during voluntary activity
- Usually recovers
spontaneously
in 1 to 4 months
Clinical Feature
Principal Pathologic Lesion: Corpus Striatum

52. Clinical Feature
Principal Pathologic Lesion:
Corpus Striatum (esp. caudate nucleus)
and Cerebral Cortex
- Predominantly autosomal dominantly
inherited chronic fatal disease
(Gene: chromosome 4)
- Insidious onset: Usually 40-50
- Choreic movements in onset
- Frequently associated with
emotional disturbances
- Ultimately, grotesque gait and sever
dysarthria, progressive dementia
ensues.
HUNTINGTON’S CHOREA

53. HEMIBALLISM
- Usually results from CVA
(Cerebrovascular Accident)
involving subthalamic nucleus
- sudden onset
- Violent, writhing, involuntary
movements of wide excursion
confined to one half of the body
- The movements are continuous
and often exhausting but cease
during sleep
- Sometimes fatal due to exhaustion
- Could be controlled by
phenothiazines and stereotaxic
surgery
Clinical Feature
Lesion: Subthalamic Nucleus

54. Muhammad Ali in Alanta Olympic
Parkinson’s
Disease
Disease of mesostriatal
dopaminergic system
PD
normal

56. Substantia Nigra,
Pars Compacta (SNc)
DOPAminergic Neuron
Slowness of Movement
- Difficulty in Initiation and Cessation
of Movement
Clinical Feature (1)
Parkinson’s Disease - Paralysis Agitans

57. Clinical Feature (2)
Resting Tremor
Parkinsonian Posture
Rigidity-Cogwheel Rigidity
Parkinson’s Disease
Paralysis Agitans