Cerebellum: 1. Gross 2. Clinical Anatomy

1. Prof Soumya Chakraborty Bhattacharya

2.  Latin for "little brain“:
dorsal part of hindbrain:
Rhombencephalon
 Plays an important role in
motor control: ipsilateral
control on body
 Posterior cranial fossa:
cerebellar fossa of
squamous part of
occipital bone

3.  Below occipital lobe
of cerebrum
separated by
tentorium cerebelli
 Anteriorly related to
dorsal surface of
pons and medulla
separated by 4th
ventricle

4.  Two lateral halves-
hemispheres
 Intermediate part-
Vermis (Worm in
appearance)
 Superior and Inferior
surfaces
 Anterosuperior aspect:
Notch: Superior
Cerebellar notch
 Posteroinferior aspect:
Notch: Posterior
cerebellar notch
related to Falx
Cerebelli

5.  Area of Vermis:
Superior vermis
 Midline ridge
 Narrow and shallow
linear depressions-
Fissures: Primary,
Horizontal,
Posterolateral: V or U
shaped presents folia
 3 lobes: Anterior,
Posterior,
Flocculonodular
Lobes

7.  Anterior and Middle
Lobes: Fissure ant
1/3 and posterior
2/3: Primary
fissure/Fissura prima
 Anteroinferior part
cut off by another
primary fissure:
Posterolateral
Fissure/ Sulcus
 Part anterior:
Flocculonodular Lobe

8.  Depression where
inferior vermis
lodged: Vallecula
 Superior and
inferior halves of
middle lobe
separated by
Horizontal fissure

9.  Lingula- No lateral
extension
 Central Lobule- Ala
 Culmen- Anterior
Quadrangular
Lobule

10.  Declive- Posterior
Quadrangular
Lobule
 Folium- Superior
Semilunar Lobule/
Lobulus Simplex

11.  Tuber- Inferior
Semilunar Lobule
 Pyramid- Biventral
Lobule
 Uvula- Tonsil
 Horizontal Fissure
divides cerebellum
into superior
(Proximal) and
inferior (Distal)halves

12.  Nodule- Flocculus

13.  Compact masses of Gray
matter in core of white
matter
 4 : either side of midline
 Lateral to Medial:
Dentate: lateral and
largest, Emboliform: oval
, Globose: round,
Fastigial: in white core of
vermis
Emboliformis and
Globosus known as
Nucleus Interpositus

14.  Archicerebellum:
Most primitive
Lingula,Flocculonodular
lobe, Fastigial Nucleus
Vestibular nuclei
through
vestibulocerebellar
fibers
Maintains equilibrium
or balance
Fishes and Amphibians

15.  Paleocerebellum:
Central Lobule and
Ala, Culmen and
Anterior
Quadrangular Lobule,
Pyramid, Uvula,
Nucleus Interpositus
Spinocerebellar fibers
Maintains muscle tone
and posture
Lower vertebrates with
limbs: Birds and
Reptiles

16.  Neocerebellum:
Development of CNS:
Telencephalization
Middle/Posterior lobe
except Pyramid and
Uvula
Dentate Nucleus
Corticopontocerebellar
path
Coordination of
voluntary
movements- smooth
and skilled

18.  Cut section shows
arrangement of
white matter in
vermis and
hemispheres
looking like trunk
and branches of a
tree known as
Arbor Vitae
Cerebelli

19.  Superior, Middle,
Inferior Cerebellar
Peduncles
connecting
Midbrain, Pons,
Medulla with
cerebellum:
Cerebellopetal and
Cerebellofugal
fibers

20.  Thinnest
 Afferent/
Cerebellopetal :
Ventral
Spinocerebellar,
Tectocerebellar tracts
 Efferent/
Cerebellofugal:
Dentatorubral,
Dentatothalamic
tracts

21.  Thickest with only
Afferent Fibers
 Afferent/
Cerebellopetal
Fibers:
Pontocerebellar
Fibers

22.  Afferent/Cerebellopetal
Fibers: Dorsal
Spinocerebellar , Anterior
External Arcuate ,
Posterior External
Arcuate/
Cuneocerebellar,
Parolivocerebellar,
Olivocerebellar,
Vestibulocerebellar,
Reticulocerebellar Fibers
 Efferent/Cerebellofugal:
Cerebelloolivary,
Cerebellovestibular,
Cerebelloreticular tracts

23.  Afferent Fibers: Enter
Through Middle and
Inferior Cerebellar
Peduncles
 Efferent Fibers: Leave
Through Superior
and Inferior
Cerebellar Peduncles
 Intrinsic Fibers: Exit
within Cerebellum

24.  3 arteries
 Superior Cerebellar Artery
 Anterior Inferior Cerebellar
Artery
 Posterior Inferior Cerebellar
Artery
 Superior Cerebellar Artery to
Cerebellar cortex, Nuclei and
Superior Cerebellar Peduncles
 Anterior Inferior Cerebellar
Artery to anterior portion of
inferior cerebellum and Middle
Cerebellar peduncles and Facial
and Vestibulocochlear nerves
 Posterior Inferior Cerebellar
Artery to posterior inferior
portion of cerebellum, Inferior
Cerebellar Peduncle, nucleus
ambiguus, vagus, motor
nucleus,
spinal trigeminal nucleus,
solitary nucleus and
vestibulocochlear nuclei.

25.  Ipsilateral control of
body
 Lesion of one half
of cerebellum :
clinical effect on
same half of body
 Maintains
equilibrium of
body/balance
 Muscle tone and
body posture
 Smooth
coordination
 Skilled movements

26.  Congenital: Hypoplasia or Dysgenesis
 Traumatic
 Ischaemic: Thrombosis of any cerebellar
arteries
 Degenerative: Multiple Sclerosis
 Neoplastic: Medulloblastoma and other
Expanding tumors

27.  Lesion of
cerebellum due to
any cause
 Motor Dysfunction
without motor
paralysis
 Archicerebellar
Syndrome
 Neocerebellar
Syndrome
 Neocerebellar
Syndrome presents
signs due to lesions
of both
paleocerebellum
and neocerebellum

28.  Lesion of
Archicerebellum:
Flocculonodular lobe
and Lingula
 Vermis Syndrome
 Common cause:
medulloblastoma of
children
 Disorders in
equilibrium: Motor
dysfunctions
 Unsteadiness in
balance: Positive
Romberg’s Sign
 Unsteadiness in Gait:
gait is style or pattern
of walking
 Sway from side to
side- Staggering Gait
 Unsteady Trunk of
body: Unable to keep
head erect moving
forwards and
backwards-
medulloblastoma in
children

29.  Combined effects of
lesions due to paleo
and neocerebellum
 Impaired functions of
paleocerebellum:
Hypotonia- Loss of
resilience of muscle,
early fatigue –
Asthenia
 Excessive movement
of terminal joints due
to loss of influence of
cerebellum on stretch
reflex
 Postural defect: Head
rotated and flexed,
shoulder on a lower
level on affected side
 Pendulous knee jerk:
Loss of stretch
reflex, series of
pendulous flexion
and extension
movement of knee
joint while knee jerk
elicited……

30.  Impaired functions
of neocerebellum:
 Incoordination or
asynergy of smooth
and precise
voluntary
movement:
Cerebellar Ataxia
 Intention Tremor:
Abnormal
Repetitive,
Oscillatory
movement affecting
distal part of limbs-
hands and fingers:
picking up an
object, buttoning
clothes

31.  Dysmetria: Finger
Nose test target:
Pastpointing
 Loss of
harmonization of
groups of muscles:
Decomposition of
movements
 Dysdiadochokinesia
: Incoordination
between functions
of antagonistic
muscles: Repeated
pronation and
supination
presents with slow ,
jerky incoordinated
manner

32.  Dysarthria: Disorder in
articulation of speech
due to incoordination
of muscles of larynx,
tongue and lips:
Slurred speech
 Nystagmus:
Incoordination of
movement of
extraocular muscles
 Rhythmical oscillation
of eyeball while fixing
the gaze for an object
for long, Horizontal
side to side movement:
sudden jerk in eyeball
at the end of
movement when gaze
returned back