**6. Neurodegenerative disorders**

#### **6.1 Agnosia**

In this disorder the ability to identify objects, persons, sound, shapes or smells are lost while the specific sense is neither defective nor is there any considerable memory loss. Usually, it is correlated with brain injury or neurological illness, especially after damage to the right parietal lobe.

#### **6.2 Alexander disease**

It is a gradually progressing and mortal neurodegenerative disease. It is an atypical disorder which results from a genetic mutation and generally has an effect on infants and children, causing developmental obstacles and changes once physical characteristics.

#### **6.3 Alpers disease**

A rare degenerative disease of the brain connecting the grey matter. It is described by the acute initiation of severe convulsions that lead to a speedy intellectual and bodily breakdown. Other features are deafness, myoclonus, blindness, choreoathetosis, spasticity, cerebellar ataxia, growth delay, plus terminal decortications. Noticeable in early childhood and generally causes death within a month.

#### **6.4 Alzheimer's disease**

The disease of the brain progresses slowly and is characterised by the devastation of memory and ultimately disturbance in planning, language, reasoning and perception.

#### **6.5 Apraxia**

This neurological disorder is described by the loss of ability to perform learned determined movements, even though having the desire to perform the physical activities. It is a disorder of motor planning which may be obtained or developmental, but it is may not be caused by sensory loss, in coordination.

#### **6.6 Batten disease**

It begins in childhood, a rare, deadly, autosomal recessive neurodegenerative disorder. It is also known as "Spielmeyer-Vogt-Sjogren-Batten" disease, it is one of the most common forms of disorders called NCLs (neuronal ceroid lipofuscinosis).
