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Neurology - Ataxia (Gait) - By Wendy Stewart M.D.
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- เผยแพร่เมื่อ 7 พ.ย. 2016
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Neurology - Ataxia (Gait)
Whiteboard Animation Transcript
with Wendy Stewart, MD
medskl.com/Mod...
Ataxia is the word we use to describe the loss of control of body movements. It may affect our trunk, one side of the body, both legs, or one limb.
We need to consider problems that affect the vestibular system, the cerebellum, and proprioceptive pathways.
Vestibular System
Problems with the vestibular system cause disequilibrium and unsteadiness. If the problem is unilateral, the patient develops profound vertigo, with associated nausea and vomiting. Drugs and alcohol are the most common causes of this type of ataxia. If it is unilateral, Menieres disease is important to consider.
Cerebellum
Like the cerebrum, the cerebellum is organized in a somatotopic distribution with the trunk control centrally and the limbs more laterally.
The midline structure is the vermis. Lesions affecting the area just lateral to and including the vermis result in truncal or gait ataxia. Patients have a wide based gait and appear “drunk”.
Lesions affecting the cerebellar hemispheres result in problems with voluntary limb movements. This is referred to as appendicular ataxia. Finger nose testing and rapid alternating movements allow observation of these difficulties. They have problems judging distances, known as dysmetria, and are unable to maintain the rhythm or amplitude of the movements, known as dysdiadochokinesia. Speech can also be affected, with variations in intensity and slurring of words. Speech can also be affected, with variations in intensity and slurring of words.
The last part of the cerebellum is the flocculonodular lobe, also known as the vestibulocerebellum. Problems in this region result in postural instability and impaired eye movement control.
Cerebellar ataxia can result from vascular lesions such as stroke or hemorrhage, inflammation, demyelination, tumors, infections, hereditary disorders, drugs or alcohol for example.
Sensory Nerves
When we think of sensory ataxia we are referring to a problem with proprioception. Lesions affecting this pathway result in an inability to stand with your eyes closed: this is a Romberg sign.
The patient may walk heavily as they cannot judge how to place their feet. They will often stumble if trying to walk in the dark as they no longer have visual input to assist them with their gait. This type of ataxia may be caused by, for example, inflammation, demyelination, vitamin deficiencies, infections, and inherited disorders.