ATAXIAATAXIA

Dr. Shamekh M. El-ShamyDr. Shamekh M. El-Shamy

THE CEREBELLUMTHE CEREBELLUM ANATOMYANATOMY: : the cerebellum is the cerebellum is

formed of 2 main parts:formed of 2 main parts: 1. A midline central structure, 1. A midline central structure,

known as the vermis. known as the vermis. 2. Two lateral cerebellar 2. Two lateral cerebellar

hemispheres.hemispheres.**cerebellum can be divided:cerebellum can be divided:1- Focculo-nodular lobe.1- Focculo-nodular lobe. 2. 2. Anterior lobe.Anterior lobe. 3- 3- Posterior lobe.Posterior lobe.

Anterior lobe

Posterior lobe

Foocculo-nodular lobe

Paleocerebellum

Neocerebellum

Archicerebellum

Archicerebellunm (flocculo-Archicerebellunm (flocculo-nodular lobe):nodular lobe):

Paleo-cerehellum (anterior Paleo-cerehellum (anterior lobe):lobe):

Neocerebellum (posterior Neocerebellum (posterior lobe): lobe):

Blood SBlood Supplyupply

The cerebellum is supplied byThe cerebellum is supplied by:: Superior cerebellar artery Superior cerebellar artery

(branch of the basilar artery).(branch of the basilar artery). Anterior inferior cerebellar Anterior inferior cerebellar

artery artery (branch of the basilar (branch of the basilar artery). artery).

Posterior inferior cerebellar Posterior inferior cerebellar artery artery (branch of the vertebral (branch of the vertebral artery).artery).

Cerebellum SyndromesCerebellum Syndromes

I.I. Archicerebellar Archicerebellar syndromesyndrome: :

II.II. Neo-cerebellar syndromeNeo-cerebellar syndrome::

There is incoordination of voluntary motor There is incoordination of voluntary motor activitiesactivities

ATAXIAATAXIA

Definition:Definition: Incoordination of Incoordination of voluntary motor activity with or voluntary motor activity with or without disequilibration in the without disequilibration in the absence of motor weakness.absence of motor weakness.

Cerebellum AtaxiaCerebellum Ataxia

Causes of Cerebellar AtaxiaCauses of Cerebellar Ataxia:: I.I. Herido-familial:Herido-familial: 1. Friedreich's ataxia. 2. 1. Friedreich's ataxia. 2.

Marie's ataxia.Marie's ataxia. II. Symptomatic :II. Symptomatic : CongenitalCongenital InfectiveInfective VascularVascular ToxicToxic

5. Neoplastic5. Neoplastic

6. Demyelination6. Demyelination

7. Metabolic7. Metabolic

III. Idiopathic:III. Idiopathic:

Clinical picture of Cerebellar Clinical picture of Cerebellar AtaxiaAtaxia

I. Incoordination of movements of I. Incoordination of movements of different muscles in the form of:different muscles in the form of:

a)Nystagmus in the eyes.a)Nystagmus in the eyes.

b) Staccato speech.b) Staccato speech.

c) Nodding of the head.c) Nodding of the head.

d) Titubaiion of the trunk.d) Titubaiion of the trunk.

e) Kinetic tremors of the e) Kinetic tremors of the limbs.limbs.

II. Hypotonia and hyporeflexia II. Hypotonia and hyporeflexia of the affected muscles.of the affected muscles.

III. III. Gait disturbance: Wide Gait disturbance: Wide base or drunken gait in base or drunken gait in archicerebellar lesions.archicerebellar lesions.

IV. Positive tests: used by the IV. Positive tests: used by the neurologist to detect neurologist to detect cerebellar ataxia.cerebellar ataxia.

TESTS OF CEREBELLAR TESTS OF CEREBELLAR ATAXIAATAXIA

1. 1. Finger to nose testFinger to nose test: :

2. Finger to doctor's finger 2. Finger to doctor's finger test: test:

you may found you may found

a) Decomposition of a) Decomposition of movement. movement.

b) Kinetic intention tremors b) Kinetic intention tremors

c) Dysmetria in the form of c) Dysmetria in the form of hypermetria or hypometriahypermetria or hypometria

3. Adiadokokinesis 3. Adiadokokinesis

4. Rebound phenomenon:4. Rebound phenomenon:

5. Heel to knee test5. Heel to knee test

HERIPO-FAMILIAL HERIPO-FAMILIAL ATAXIASATAXIAS

I. Friedreich's AtaxiaI. Friedreich's Ataxia1. It occurs in the 1st decade of 1. It occurs in the 1st decade of

life.life.

2. Gradual onset and slowly 2. Gradual onset and slowly progressive course.progressive course.

3. Positive family history is 3. Positive family history is common as it is inherited as an common as it is inherited as an autosomal recessive disease.autosomal recessive disease.

44. Pathologically there is . Pathologically there is degeneration of:degeneration of:

- Cerebellum specially the - Cerebellum specially the archicercbcllum &archicercbcllum & the the spinocerebellar tracts.spinocerebellar tracts.

- Pyramidal tracts.- Pyramidal tracts.

- Posterior columns.- Posterior columns.

- Peripheral nerves.- Peripheral nerves.P.N

II. II. Marie's AtaxiaMarie's Ataxia1. It occurs in the 2nd and 3rd 1. It occurs in the 2nd and 3rd

decades of life.decades of life.

2. Gradual onset and slowly 2. Gradual onset and slowly progressive course.progressive course.

3. Pathologically there is degeneration 3. Pathologically there is degeneration of: of: 

- Cerebellum specially the neo-- Cerebellum specially the neo-cerebellum (dentate nucleus)cerebellum (dentate nucleus)

-Pyramidal tracts.-Pyramidal tracts.

- It presents with progressive - It presents with progressive manifestations of neocerebellar manifestations of neocerebellar degenerationdegeneration..

- Mental impairment, ocular nerve - Mental impairment, ocular nerve paralysis and extrapyramidal paralysis and extrapyramidal syndromes are occasionally syndromes are occasionally present.present.

SENSORY ATAXIASENSORY ATAXIA  

Definition:- Definition:- It is ataxia due to It is ataxia due to loss of the proprioceptive (deep) loss of the proprioceptive (deep) sensations, at any point in their sensations, at any point in their pathway.pathway.

Causes :-Causes :-

4. Medial lemniscus : 4. Medial lemniscus : brain brain stem lesions. stem lesions.

5. Thalamus : 5. Thalamus : thalamic thalamic syndrome. syndrome.

6. Cortical sensory area : 6. Cortical sensory area : parietal lobe lesions.parietal lobe lesions.

Rhomberg’s Test :Rhomberg’s Test :

VESTIBULAR ATAXIAVESTIBULAR ATAXIA

Definition :- Definition :- It is ataxia due to It is ataxia due to lesions of the vestibular division of lesions of the vestibular division of the eighth nerve.the eighth nerve.

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