Since the brain controls or supervises a large part of our body’s functions, damage to different regions of this structure can lead to a variety of alterations. Aphasias are a type of language disorder that occurs as a result of damage to language-related areas of the brain.
In this article we will describe the symptoms and causes of Broca’s aphasia , expressive, motor or production aphasia. This neuropsychological disorder consists of the alteration of expressive language as a consequence of damage to the frontal lobe, although auditory comprehension is not necessarily affected, as in other types of aphasia.
What is aphasia?
Aphasias are language disorders that appear as a result of lesions in certain regions of the brain, mainly due to head injuries and strokes, also called heart attacks or strokes. The term is based on classical Greek and translates as “inability to speak”.
There are different types of aphasia that are characterized by idiosyncratic combinations of alterations in four linguistic domains: verbal comprehension, oral expression, functional communication and literacy . Most of them share the presence of anomie, which consists of persistent difficulty in recovering words from memory.
Other common signs and symptoms of aphasia are articulatory and comprehension deficits, reduced spontaneous language, inability to read and/or write, dysprosody (alterations in the tone and rhythm of speech) and the use of neologisms (in psychopathology, words that only have meaning to the speaker).
Therefore aphasias do not only affect spoken language, but also written language and mimicry , including sign language. This is because all these forms of communication depend on the same cognitive functions, related to brain structures and pathways that are damaged in aphasia.
Symptoms and Signs of Broca’s Aphasia
The basic signs of Broca’s aphasia are related to speech production. People with this syndrome have severe difficulties finding words and articulating sentences fluently, and the prosody of speech is also affected, causing speech to be monotonous. Writing is equally affected.
In the context of this disorder , “telegraphic speech” is often used to refer to the way those who suffer from it express themselves: they pause a lot because they have a lot of difficulty in articulating (or gesturing) words that are not of content, i.e. they communicate mainly through successions of nouns and verbs.
The intensity of these symptoms depends on the severity of the injury; while in some cases only mild anomie, moderate reductions in expressive fluidity and the phenomenon of “foreign accent” appear, in others the person may be unable to utter any words at all. In most cases, at least the more formulaic expressions are retained.
Since regions related to Broca’s aphasia are involved in motor skills, it is not surprising that the brain lesions that cause it also cause motor signs. These include hemiparesis (paralysis in one half of the body), apraxia (deficit in purposeful movements) and dysarthria, which affects pronunciation .
In a synthetic way we can say that the main characteristics of Broca’s aphasia are the following:
- Lack of spontaneous language fluency
- Handwriting alterations
- Maintenance of listening and reading comprehension
- Word repetition deficit
- Problems remembering words, such as names of objects (anomie)
- Associated motor disorders (dysarthria, apraxia, hemiparesis)
Causes of this disorder
Broca’s aphasia appears as a consequence of lesions in the anterior part of the brain, especially in the frontal lobe of the left hemisphere, which plays a more relevant role than the right one in the execution of movements, including those necessary for speech and writing.
Although the name of the disorder is associated with Brodmann’s area 44 , known as “Broca’s area” , damage that is limited to this brain region causes only mild linguistic and motor symptoms. The most severe manifestations appear when the damage extends to surrounding areas, such as the anterior insula, the precentral gyrus and the opercular region.
The most common cause of Broca’s aphasia is ischemic strokes, which consist of the interruption of blood flow, and therefore oxygen, to a certain area of the brain. In this case the regions affected by oxygen hypoperfusion are those mentioned in the previous paragraph.
With some frequency the brain injuries that cause this type of aphasia are due to other reasons; the most frequent are cranioencephalic trauma, cerebral hemorrhages , brain tumors located near the language areas and extradural hematomas (accumulations of blood or other fluids between the meninges and the skull).