Global Aphasia

Global aphasia is an extreme impairment or loss of language ability in all input and output modalities. The main cause of global aphasia is an injury on the Broca's and Wernicke's area of the brain which is responsible for language processing. With an impairment of language in all modalities, global aphasia is the most severe type of the aphasias.
Sufferers of global aphasia have very poor language comprehension as well as the inability to speak or write. Unlike other forms of aphasia, which target specific language functions such as the ability to produce fluent speech or comprehend language, a person who develops global aphasia from brain damage is incapable of speaking or understanding spoken language. Since they have no ability to speak or comprehend spoken language, much of the communication done by a sufferer of global aphasia is through facial gestures and signs.
For further comprehension about global aphasia, have a look at its general symptoms below:
1.    Depression
2.    Impairment in word based communication (reading, writing, spellings, speaking, etc)
3.    Speak words that are not recognizable
4.    Unable to comprehend a conversation
5.    Writing words or sentences that don't make proper sense
6.    Formation of short and incomplete words and sentences

Many patients with global aphasia are quite proficient at making their needs understood without producing spoken or written speech. Some of the ways in which patients with global aphasia may communicate successfully include prosody, inflection, pointing, and expressions of approval or disapproval. Recovery in the first 6 months generally outpaces later recovery; however, some patients can recover function years after the initial injury.
Actually, The exact symptoms vary from individual to individual. For example, some globally aphasic persons do not understand speech at all, while others recognize familiar personal names and are able to follow whole-body commands. Similarly, some individuals are mute, while others can produce a few sounds (e.g., "ta, ta") or stereotypic phrases (e.g., "we said").