ATAXIA: What Does it Mean

 Ataxia is a Poor coordination and unsteadiness due to the brain's failure to regulate the body's posture and regulate the strength and direction of limb movements. Ataxia is usually due to disease in the cerebellum of the brain, which lies beneath the back part of the cerebrum.

General analysis of the case:

A) Patient complains:

1. Instability of walking and repeated falling down (poor balance or decreased equilibrium)
2. Shaking of the hand at the start of the action( intention tremor)

B) Signs which has been seen by the physician:

1. Slurred speech (dysarthria)

C) Other condition of the patient:

1. He is known hypertensive case for 10 years; his BP is 190/90 with medication.

D) Important negative data:

1. No alcohol consumption, because alcohol can produce the same clinical picture.

E) Provisional diagnosis:

All symptoms and signs indicating cerebellar disease because:

1. Instability of walking and repeated falling down --> poor balance ---> balance is the function of vestibulocerebellum.
2. Intention tremors ---> loss of damping function which is a function of the spinocerebellum.
3. Dysarthria ----> loss of timing function which is a function of the cerebrocerebellum.

Tasks:

Tasks 1 & 2:

• Head region tests:
• Eye examination Nystagmus
• Hypotonia of the face and neck muscles and this result in pulling of the face toward the normal side ((defective attitude))
• Dysarthria broken speech because cerebellum controls the vocal cords.
• Upper limbs teat:
• Finger – nose – finger test. Overshooting and missing of the wanted point. Dysmetria or post-pointing or intention tremors.
• Fast alternative movements ((Dysdiadochokinesia))
• Rebound phenomena. The patient hand will slip to hit his face.
• Lower limbs test:
• Straight line test. The patient is unable to walk in a straight line and he has a drunken gait.
• Heel-shin test. The heel wavers away from the line of the shin.
• Reflexes:
• Cerebellar damage --> muscle Hypotonia.
• Deep tendon reflexes (knee reflex) --> pendular and weak (hyporeflexia)
• Superficial reflexes (plantar reflex) --> weakened.

Task3:

C.T. or MRI.

Task 4:

By executing a Romberg’s test we can identify the site of the lesion 

1. Positive Romberg’s test suggest a dorsal column lesion (( sensory ataxia))
2. Negative Romberg’s test suggests lesion to the midline and adjacent structures of the cerebellum.

The lesion could be:

• Tumors.
• Hemorrhage.
• Infarction.
• Abscesses.
• Multiple sclerosis.

Task 5:

The loss of the damping function of the cerebellum ---> overshooting ---> correction ---> repeated overshooting and correction leads to the shaking of the hands. (Intention tremors).

Task 6:

Because the equilibrium function (controlling the contraction of the agonist and antagonist muscle groups) of the cerebellum is disturbed. 

Task 7:

Dr.Wajid said that we should cross this question because it is unreasonable.

Task 8:

He has this problem because the formation of words depends on rapid and orderly succession of individual muscle movements in the larynx, mouth, and respiratory system. Lack of coordination among these and inability to adjust in advance either the intensity of sound or duration of each successive sound causes jumbled vocalization, with some syllables loud, some weak, some held for long intervals, some held for short intervals, and resultant speech that is often unintelligible. This is called dysarthria.

Task 9:

They are the Anterior and posterior spinocerebellar tracts.

You need to know these facts about these tracts:

• Course.
• Contra or ipsilateral tract.
• Number of synapses.
• Type of information transmitted.

These information can be found in neuroanatomy by Snell pages 147-150  and figure 4-13 page 149 and the table 4-3 page 150

by

Akshaya Srikanth

Pharm.D Resident

Hyderabad, India