The term basal nuclei is applied to a collection of masses of gray matter situated within each cerebral hemisphere. They are the corpus striatum, amygdaloid nucleus, claustrum. The subthalamic nuclei, the substantia nigra, and the red nucleus are functionally closely related to the basal nuclei.

1. BASAL NUCLEI
by Dr Abdul Qayyum khan

2. BASAL NUCLEI
 The term basal nuclei is applied to a collection of
masses of gray matter situated within each
cerebral hemisphere.
 They are the
 corpus striatum
 amygdaloid nucleus
 claustrum.
 The subthalamic nuclei, the substantia nigra, and
the red nucleus are functionally closely related to
the basal nuclei.

3. CORPUS STRIATUM
 The corpus striatum is situated lateral to the thalamus
and is almost completely divided by a band of nerve
fibers, the internal capsule, into the caudate nucleus
and the lentiform nucleus.

5. CAUDATE NUCLEUS
 Large C-shaped mass of gray
matter that is closely related to the
lateral ventricle and lies lateral to
the thalamus
 lateral surface of the nucleus is
related to the internal capsule,
which separates it from the
lentiform nucleus
 Divided into
 Head
 Body
 Tail

6.  Head—large and
rounded,forms lateral wall
of anterior horn of lateral
ventricle
 Body__long and
narrow,forms the floor of
body of lateral ventricle
 Tail---long and narrow,forms
the roof of inferior horn
 Terminates anteriorly in
amydaloid nucleus

7. LENTIFORM NUCLEUS
 The lentiform nucleus is a wedge-shaped mass of gray matter
whose broad convex base is directed laterally and whose
blade is directed medially
 related medially to the internal capsule, which separates it
from the caudate nucleus and the thalamus
 2 parts
 Putamen
 Globus pallidus
 External capsule
 Claustrum

9. AMYDALOID NUCLEUS
 The amygdaloid nucleus is situated in the temporal
lobe close to the uncus .
 The amygdaloid nucleus is considered to be part of
the limbic system

10. CLAUSTRUM
 The claustrum is a thin sheet of gray matter that is
separated from the lateral surface of the lentiform
nucleus by the external capsule
 Lateral to the claustrum is the subcortical white
matter of the insula.
 The function of the claustrum is unknown.

11. CONNECTIONS OF THE CORPUS STRIATUM
 AFFERENT FIBERS
Corticostriate Fibers
 All parts of the cerebral cortex send axons to the caudate
nucleus and the putamen
 Each part of the cerebral cortex projects to a specific part
of the caudate-putamen complex.
Thalamostriate Fibers
 The intralaminar nuclei of the thalamus send large
numbers of axons to the caudate nucleus and the putamen

12. Nigrostriate Fibers
 Neurons in the substantia nigra send axons to the
caudate nucleus and the putamen
Brainstem Striatal Fibers
 Ascending fibers from the brainstem end in the
caudate nucleus and putamen

13. EFFERENT FIBERS
Striatopallidal Fibers
 Striatopallidal fibers pass from the caudate nucleus
and putamen to the globus pallidus
Striatonigral Fibers
 Striatonigral fibers pass from the caudate nucleus
and putamen to the substantia nigra

14. CONNECTIONS OF THE GLOBUS PALLIDUS
 AFFERENT FIBERS
Striatopallidal Fibers
 Striatopallidal fibers pass from the caudate nucleus
and putamen to the globus pallidus..

15. EFFERENT FIBERS
 Pallidofugal Fibers
 Pallidofugal fibers are divided into groups:
(1) the ansa lenticularis, which pass to the thalamic nuclei
(2) the fasciculus lenticularis, pass to the subthalamus;
(3) the pallidotegmental fibers, which terminate in the
midbrain
(4) the pallidosubthalamic fibers, which pass to the
subthalamic nuclei.

17. FUNCTIONS OF THE BASAL NUCLEI
 The basal nuclei control muscular movements by
influencing the cerebral cortex and have no direct
control through descending pathways to the
brainstem and spinal cord.
 In this way, the basal nuclei assist in the regulation
of voluntary movement and the learning of motor
skills.

18. CLINICAL NOTES
 Disorders of the basal nuclei are of two general
types.
 Hyperkinetic disorders
 Hypokinetic disorders

19. CHOREA
 In chorea, the patient exhibits involuntary, quick,
jerky, irregular movements that are non repetitive
 Huntington disease
 Sydenham chorea

20. HUNTINGTON DISEASE
 Autosomal dominant inherited disease
 Characterized by
 Choreiform movements
 Progressive dementia

21. SYDENHAM CHOREA
 Sydenham chorea (St. Vitus' dance) is a disease of
childhood in which there are rapid, irregular,
involuntary movements of the limbs, face, and
trunk.
 The condition is associated with rheumatic fever

22. HEMIBALLISMUS
 Hemiballismus is a form of involuntary movement
confined to one side of the body.
 Lesion occurs in the opposite subthalamic nucleus
or its connections

23. PARKINSON DISEASE
 Parkinson disease is a progressive disease of
unknown cause.
 It is associated with neuronal degeneration in the
substantia nigra and, to a lesser extent, in the
globus pallidus, putamen, and caudate nucleus.

24. PARKINSON DISEASE
 Tremer
 Rigidity
 Bradykinesia
 Postural disturbances
 No loss of muscle power and no loss of sensibility

25. ATHETOSIS
 Athetosis consists of slow, sinuous, writhing
movements that most commonly involve the distal
segments of the limbs.
 Degeneration of the globus pallidus

26. REFERENCES
 Snell’s neuroanatomy …. 8th edition
 Gray’s anatomy 39th edition