CEREBLLAR DYSFUNCTION Flashcards

1
Q

The _________, located inferiorly,
which is phylogenetically the oldest portion of the
cerebellum and is much the same in all animals (hence
archicerebellum) .

It is separated from the main mass of
the cerebellum, or corpus cerebelli, by the__________

A

flocculonodular lobe

posterolateral fissure.

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2
Q

The anterior lobe, or paleocerebellum, which

is the portion rostral to the_____

A

primary fissure

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3
Q

The ____________,
consisting of the middle divisions of the vermis and
their large lateral extensions

A

posterior lobe, or neocerebellum

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4
Q

The
flocculonodular lobe receives special proprioceptive
impulses from the_________i and is therefore
also referred to as the vestibulocerebellum;

A

vestibular nucle

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5
Q

The anterior vermis
and part of the posterior vermis are referred to as
the _________ since projections to these parts
derive to a large extent from the proprioceptors of
muscles and tendons in the limbs and are conveyed to
the cerebellum in the dorsal spinocerebellar tract (from
the lower limbs) and the ventral spinocerebellar tract
(upper limbs) .

A

spinocerebellum,

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6
Q

The main influence of the spinocerebellum

appears to be on______ and _____

A

posture and muscle tone

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7
Q

The neocerebellum derives its afferent fibers indirectly from the cerebral cortex via the pontine nuclei and brachium pontis, hence the designation ________

A

pontocerebellum.

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8
Q

Lesions of the nodulus and flocculus

have been associated with a disturbance of ______

A

equilibrium

and frequently with nystagmus

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9
Q

The ________, which receives both peripheral and central projections (from motor cortex), influences postural tone and also individual movements of the ipsilateral limbs.

The lateral zone is concerned mainly with _______ but is also involved
in other functions.

A

intermediate
zone

coordination
of movements of the ipsilateral limbs

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10
Q

The projections from Purkinje cells are ______ whereas those from the nuclei are excitatory on other parts of the motor nervous system.

A

inhibitory

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11
Q

The deep cerebellar nuclei, in turn, project to the
cerebral cortex and certain brainstem nuclei via two
main pathways:

fibers from the dentate, emboliform,
and globose nuclei form the _______
enter the upper pontine tegmentum as the brachium
conjunctivum, decussate at the level of the inferior colliculus, and ascend to the __________ of the
thalamus and, to a lesser extent, to the intralaminar
thalamic nuclei

Some of the ascending fibers,
soon after their decussation, synapse in the _____
but most of them traverse this nucleus without terminating, and pass on to the thalamus

A

superior cerebellar peduncle,

ventrolateral nucleus

red nucleus,

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12
Q

A
small group of fibers of the superior cerebellar peduncle,
following their decussation, descend in the ventromedial
tegmentum of the brainstem via the central
tegmental fasciculus and terminate in the reticulotegmental
and paramedian reticular nuclei of the pons and
inferior olivary nuclei of the medulla.

A

Guillain-Mollaret triangle

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13
Q

The _________sends fibers to the vestibular

nuclei of both sides and, to a lesser extent, to other nuclei of the reticular formation of the pons and medulla

A

fastigial nucleus

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14
Q

The _______ project via the restiform body (inferior cerebellar
peduncle) to the contralateral cerebellar cortex and corresponding
parts of the deep cerebellar nuclei.

A

inferior olivary

nuclei

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15
Q

The
dentate nucleus receives information from the premotor
and supplementary motor cortices via the pontocerebellar system and helps to initiate _________

A

volitional movements

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16
Q

The _______ also receives
cerebrocortical projections via the pontocerebellar system;
in addition, it receives spinocerebellar projections
via the intermediate zone of the cerebellar cortex

A

interpositus nucleus

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17
Q

Also, the _________ appears to be
responsible for making volitional oscillations (alternating
movements) .

A

prepositus nucleus

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18
Q

The _________controls antigravity and
other muscle synergies in standing and walking; ablation
of this nucleus greatly impairs these motor activities

A

fastigial nucleus

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19
Q

The cerebellar cortex is configured as a stereotyped

________containing______types of neurons

A

three-layered structure

five

20
Q

The outermost “molecular” layer of the cerebellum
contains two types of inhibitory neurons, the _____
and the ________

A

stellate cells

basket cells

21
Q

The _______ constitute
the main output of the cerebellum, which is directed at
the deep cerebellar and vestibular nuclei

Purkinje cells are likewise entirely inhibitory and utilize
the neurotransmitter _______

A

Purkinje cell axons

gamma-aminobutyric acid (GABA)

22
Q

The innermost “granular” layer contains an enormous
number of densely packed ______ and a few larger
________

A

granule cells

Golgi interneurons

23
Q

The predominant afferent input to the cerebellum is
via the_________which are the axons of the ___________ and the projections from pontine, vestibular,
and reticular nuclei

A

mossy fibers,

spinocerebellar
tracts

24
Q

Mossy fibers ramify in
the granule layer and excite Golgi and granule neurons
through special synapses termed ________

A

cerebellar glomeruli.

25
Q

The other main afferent input is via the_______
which originate in the inferior olivary nuclei (olives) and
communicate somatosensory, visual, and cerebral cortical
signals

A

climbing fibers,

26
Q

The climbing fibers have specific excitatory

effects on Purkinje cells that result in prolonged ________

A

“complex spike” depolarizations

27
Q

Four of the five cell types of the cerebellar cortex

(Purkinje, stellate, basket, Golgi) are ________

A

inhibitory

28
Q

Afferent fibers
to the cerebellum are of three types, two of which have
been mentioned above: (1) ________, which are the
main afferent input to the cerebellum, utilize aspartate.
(2) _______, which are the axons of cells in the
inferior olivary nucleus and project to the Purkinje cells of
the opposite cerebellar hemisphere.

3) _______, which project through the superior cerebellar peduncle and terminate on
the Purkinje and granule cells in all parts of the cerebellar
cortex.

A

Mossy fibers

Climbing fibers

Aminergic fibers

29
Q

The__________ elaborate the excitatory
transmitter glutamate.

All the inhibitory cerebellar cortical
neurons appear to utilize ______

A

granule cell axons

GABA.

30
Q

the fragmentation of a smooth movement into

a series of irregular, jerky components

A

decomposition

31
Q

with cerebellar lesions, there is a _________ between the commanded act and the onset of movement

A

prolongation of the interval

32
Q

Extensive lesions of one cerebellar hemisphere,
especially of the ________, cause mild hypotonia,
postural abnormalities, ataxia, and a mild weakness
of the ipsilateral arm and leg perceived by the patient

A

anterior lobe

33
Q

Lesions
involving the superior cerebellar peduncle or the dentate
nucleus cause the most severe and enduring cerebellar
symptoms, which manifest mostly as ________

A

ataxia in the

ipsilateral limbs.

34
Q

Damage in the _______ causes
vestibulocerebellar symptoms-namely, dizziness, vertigo,
vomiting, and nystagmus-in varying proportions

A

inferior cerebellum

35
Q

With
cerebellar disease, the _________ of the movement
are not checked in the normal manner.

A

velocity and force

36
Q

This side-toside movement of the finger as it approaches its mark tends to assume a rhythmic quality; it has traditionally
been referred to as i___________

A

intention tremor, or ataxic tremor

37
Q

Holmes called it rubral tremor, and although the
______ may be the site of the lesion, the nucleus itself
is not necessarily involved in this type of tremor.

Instead, it is a result of interruption of the fibers of the superior cerebellar peduncle, which traverse the nucleus, for which reason it may be more properly called _______

A

red nucleus

“cerebellar outflow
tremor.”

38
Q

Smooth pursuit
movements are slower than normal and require that the
patient make small _________ in an attempt
to keep the moving target near the fovea

A

“catch-up” saccades

39
Q

nystagmus
caused by cerebellar disease depends on lesions of
the _______

A

vestibulocerebellum

40
Q

disequilibrium
syndrome, with normal movements of the limbs,
corresponds more closely with lesions of the ________than with those of the flocculus and nodulus

A

anterior

vermis

41
Q

acute cerebellar lesions and hypotonia

are associated with a depression of _________

A

fusimotor efferent

and spindle afferent activity

42
Q

after strongly flexing one arm against a
resistance that is suddenly released, the patient may be
unable to check the flexion movement, to the point where
the arm may strike the face

A

Holmes’ rebound phenomenon,

43
Q

________i.e., brief (50- to 100-ms),
random contractions of muscles or groups of musclesare,
in some disease processes, combined with cerebellar
ataxia

A

Myoclonic movements-

44
Q

Cognitive changes show a wide range of subtle _________ in patients with disease apparently limited to the cerebellum

A

alterations of

memory and cognition, language function, and behavior

45
Q

Th e ataxia of severe sensory neuropathy and o f posterior column or posterior spinal root disease (sensory
ataxia) simulates cerebellar ataxia; presumably this is a
result of involvement of the _______

_________ and _______
are prime examples of this type of disorder

A

large peripheral spinocerebellar
afferent fibers

Tabes dorsalis and sensory ganglionopathy

46
Q

A cerebellar type of tremor
reaches an extreme form in the large-fiber polyneuropathy
related to antibodies against _________
but the features are closer to an enhanced action
tremor,

A

myelin-associated glycoprotein