S: https://www.nlm.nih.gov/medlineplus/aphasia.html (last access: 26 February 2016); https://learningdisabilityaid.wordpress.com/2014/05/16/dysphasia-explained/ (last access: 26 February 2016).
N: 1. From dys- meaning difficult, painful, bad, disordered, abnormal + the Greek phasis meaning speech.
2. One in a group of speech disorders in which there is impairment of the power of expression by speech, writing, or signs, or impairment of the power of comprehension of spoken or written language. More severe forms of dysphasia are called aphasia.
3. Dysarthria is a speech disorder caused by disturbance of muscular control. Dysphasia (also called aphasia) is an impairment of language. They often co-exist.
Strictly speaking, the words anarthria and aphasia mean a total absence of ability to form speech or language but they are often used when dysarthria and dysphasia would be more correct. In particular, dysphasia and aphasia are used interchangeably, with aphasia in more common use.
4. Dysphasia can be receptive or expressive. Receptive dysphasia is difficulty in comprehension, whilst expressive dysphasia is difficulty in putting words together to make meaning. In reality there is usually considerable overlap of these conditions but a person who has pure dysarthria without dysphasia would be able to read and write as normal and to make meaningful gestures, provided that the necessary motor pathways are intact.
5. Apraxia of speech is different to both dysphasia and dysarthria, and is the loss of ability to plan and execute the oral motor tasks needed in order to speak.
6. Inability to write is agraphia or dysgraphia if incomplete. Inability to manipulate numbers is acalculia or dyscalculia if incomplete. Difficulty reading is dyslexia.
S: 1 & 2. http://www.medicinenet.com/script/main/art.asp?articlekey=31169 (last access: 26 February 2016). 3 to 6. http://patient.info/doctor/Dysarthria-and-Dysphasia (last access: 26 February 2016).