Aphasia is a condition characterized by the inability to express and understand both spoken and written language. People with aphasia can make sounds and noises. Some patients produce unrecognizable words or incomprehensible sentences.
Patients with non-fluent aphasia can only utter short, simple incomplete sentences. These individuals can usually understand what other people are saying and are aware that they have a language deficit.
Patients with fluent aphasia produce word-like and sentence-like sounds that are meaningless. These patients often cannot comprehend what others are saying and are usually unaware that they are speaking unintelligibly.
Patients with global aphasia cannot speak or comprehend language.
Most cases of aphasia are caused by strokes, head injuries, brain tumors or neurodegenerative diseases.