Introduction
Aphasia is a term used to describe a disturbance in the ability to use symbols (written or spoken) to communicate information. It is categorized into 2 types: expressive aphasia and receptive aphasia. These 2 types of aphasia can occur together. This topic discusses Broca aphasia (also called expressive aphasia). Broca aphasia was first described by the French physician Pierre Paul Broca in 1861. A mild form of this condition is termed dysphasia. Aphasia/dysphasia should be distinguished from dysarthria, which results from impaired articulation. Dysarthria, as opposed to aphasia, is a motor dysfunction due to disrupted innervation to the face, tongue, or soft palate, resulting in slurred speech but intact fluency and comprehension. Aphasia is typically considered a cortical sign. Its presence suggests dysfunction of the dominant cerebral cortex.[1][2][3]
Etiology
The most common cause of Broca aphasia is a stroke involving the dominant inferior frontal lobe or Broca area. A stroke in the Broca area is usually due to a thrombus or emboli in the middle cerebral artery or internal carotid artery. Other causes of Broca aphasia include traumatic brain injury, tumors, and brain infections. Aphasia is a symptom of degenerative dementing illnesses such as Alzheimer disease. With dementing illness, patients develop gradual progressive language deficits as opposed to a sudden onset of loss of language function that is seen in an ischemic stroke.[4]
Epidemiology
Data on the incidence of Broca aphasia are limited. In the United States, approximately 170,000 new cases of aphasia related to stroke occur annually.[5]
Pathophysiology
The Broca area is a region in the inferior frontal lobe of the brain's dominant hemisphere, comprising Brodmann areas 44 and 45. Language function is lateralized to the left hemisphere in 96% to 99% of right-handed people and 60% of left-handed people. Various pathways connect the Broca area to the frontal lobe, basal ganglia, cerebellum, and contralateral hemisphere. As a result of a lesion in the Broca area, there is a breakdown between one's thoughts and one's language abilities. Thus, patients often feel that they know what they wish to say but cannot produce the words. They cannot translate their mental images and representations into words. This affects the normal fluency of speech. The loss of language function may be due to the Broca area's role in ordering sounds into words and words into sentences, thereby creating relationships among linguistic elements.
History and Physical
Broca aphasia is non-fluent aphasia. The output of spontaneous speech is markedly diminished. There is a loss of normal grammatical structure (agrammatic speech). Specifically, small linking words, conjunctions (and, or, but), and the use of prepositions are lost. For example, a sentence like "I took the dog for a walk" may become "I walk the dog." Patients can exhibit interjectional speech with a long latency, and the words expressed are produced as if under pressure. The ability to repeat phrases is also impaired. Despite these impairments, the produced words are often intelligible and contextually correct. In pure Broca aphasia, comprehension is intact. Patients with Broca aphasia are often very upset about their difficulty communicating. This may be due to a deficit or damage to adjacent frontal lobe structures that control the inhibition of negative emotions. Broca aphasia can accompany other neurological deficits such as right facial weakness, hemiparesis or hemiplegia, and apraxia.
Evaluation
Bedside examination of a patient with suspected aphasia includes assessments of fluency, the ability to name objects, repeat short phrases, follow simple and complex commands, and read and write. Formal neuropsychological testing may help determine the type and severity of the language deficit. Neuroimaging may be required to localize and diagnose the cause of aphasia. Patients should also be screened for depression, as this is also common in Broca aphasia.[6]
Treatment / Management
Broca aphasia often has a devastating effect on the ability of individuals to carry out their normal activities. It affects the patient's ability to communicate, often leading to loss of productivity, vocation, and social isolation.[7][8][9] Currently, there is no standard treatment for Broca aphasia. Treatments should be tailored to each patient's needs. Speech and language therapy is the mainstay of care for patients with aphasia. It is essential to provide aphasic patients with a means to communicate their wants and needs so these may be addressed. Often, this is done by providing a board with various objects so the patient can point to the object they want. The involvement of a speech therapist, neuropsychologist, and neurologist in developing a care plan for the patient with Broca aphasia is very helpful in obtaining a good outcome. One innovative treatment option for patients with Broca aphasia is melodic intonation. Melodic intonation relies on the fact that musical ability is often spared in Broca aphasia. Thus, the speech therapist encourages patients with poor speech production to express their words with musical tones. This approach has shown promise in clinical trials.
Medical treatment of aphasia is currently under investigation in clinical trials. Drug therapies have included catecholaminergic agents (bromocriptine, levodopa, amantadine, dexamphetamine), piracetam and related compounds, acetylcholine esterase inhibitors, and neurotrophic factors. Previous studies have been small, and further studies are needed to determine the efficacy of these pharmacological agents. Also, trials of transcranial magnetic stimulation and transcranial direct stimulation for aphasia are currently underway. When the cause of Broca aphasia is a stroke, recovery of language function peaks within 2 to 6 months, after which time further progress is limited. However, patients should be encouraged to work on speech production, as improvements have been observed long after a stroke. There are commercial software products available that claim to improve language function, but for the most part, these have not been rigorously tested in randomized clinical trials. It is important to address issues of post-stroke depression and post-stroke cognitive impairment, as well as disorders of executive function, awareness, neglect, and hemiparesis during the rehabilitation process to optimize the outcome for an individual patient. Family and social support are extremely important to keep patients with language deficits engaged in social and leisure activities, which can greatly influence the aphasic patient’s quality of life.
Differential Diagnosis
Differential diagnosis for Broca aphasia includes:
Anterior circulation stroke
Cardioembolic stroke
Central pontine myelinolysis
Cerebral venous thrombosis
Dementia in motor neuron disease
Dissection syndrome
Frontal lobe syndrome
Glioblastoma multiforme
Head injury
Pearls and Other Issues
When speaking to a patient with aphasia, it is important to maintain a normal rate and volume. Questions should be simple. It is preferable to ask yes or no questions rather than open-ended ones requiring a lengthy answer.
Enhancing Healthcare Team Outcomes
Broca aphasia is often seen in patients with head trauma or a stroke. While the individual has preserved comprehension, they have trouble speaking fluently. These patients often undergo speech therapy but are cared for by nurses because of their other illnesses. Hence, nurses need to be aware of this speech disorder. Individuals with this disorder may be able to read, but their writing ability may be limited. However, it is important to appreciate that in Broca aphasia, intellectual and cognitive functions are preserved.[10][6] Some patients may recover functionally and lead an independent life, as long as they do not have other comorbidities or neurological deficits. The recovery after Broca aphasia is often many months or even years, especially if the cause was a stroke. Most people see mild improvement within the first 6 months, but full recovery can take years. The key is to educate the family members of caregivers who are looking after patients.[11]
References
- 1.
Ripamonti E, Frustaci M, Zonca G, Aggujaro S, Molteni F, Luzzatti C. Disentangling phonological and articulatory processing: A neuroanatomical study in aphasia.
Neuropsychologia. 2018 Dec;121:175-185. [
PubMed: 30367847]
- 2.
Friedrich P, Anderson C, Schmitz J, Schlüter C, Lor S, Stacho M, Ströckens F, Grimshaw G, Ocklenburg S. Fundamental or forgotten? Is Pierre Paul Broca still relevant in modern neuroscience?
Laterality. 2019 Mar;24(2):125-138. [
PubMed: 29931998]
- 3.
Grossman M, Irwin DJ. Primary Progressive Aphasia and Stroke Aphasia.
Continuum (Minneap Minn). 2018 Jun;24(3, BEHAVIORAL NEUROLOGY AND PSYCHIATRY):745-767. [
PMC free article: PMC7988735] [
PubMed: 29851876]
- 4.
Fridriksson J, Fillmore P, Guo D, Rorden C. Chronic Broca's Aphasia Is Caused by Damage to Broca's and Wernicke's Areas.
Cereb Cortex. 2015 Dec;25(12):4689-96. [
PMC free article: PMC4669036] [
PubMed: 25016386]
- 5.
Ochfeld E, Newhart M, Molitoris J, Leigh R, Cloutman L, Davis C, Crinion J, Hillis AE. Ischemia in broca area is associated with broca aphasia more reliably in acute than in chronic stroke.
Stroke. 2010 Feb;41(2):325-30. [
PMC free article: PMC2828050] [
PubMed: 20044520]
- 6.
Des Roches CA, Vallila-Rohter S, Villard S, Tripodis Y, Caplan D, Kiran S. Evaluating Treatment and Generalization Patterns of Two Theoretically Motivated Sentence Comprehension Therapies.
Am J Speech Lang Pathol. 2016 Dec 01;25(4S):S743-S757. [
PMC free article: PMC5569623] [
PubMed: 27997950]
- 7.
Ali N, Rafi MS, Ghayas Khan MS, Mahfooz U. The effectiveness of script training to restore lost communication in a patient with Broca's aphasia.
J Pak Med Assoc. 2018 Jul;68(7):1070-1075. [
PubMed: 30317304]
- 8.
Silva FRD, Mac-Kay APMG, Chao JC, Santos MDD, Gagliadi RJ. Transcranial direct current stimulation: a study on naming performance in aphasic individuals.
Codas. 2018 Aug 30;30(5):e20170242. [
PubMed: 30184007]
- 9.
Hartwigsen G, Saur D. Neuroimaging of stroke recovery from aphasia - Insights into plasticity of the human language network.
Neuroimage. 2019 Apr 15;190:14-31. [
PubMed: 29175498]
- 10.
Fridriksson J, Rorden C, Elm J, Sen S, George MS, Bonilha L. Transcranial Direct Current Stimulation vs Sham Stimulation to Treat Aphasia After Stroke: A Randomized Clinical Trial.
JAMA Neurol. 2018 Dec 01;75(12):1470-1476. [
PMC free article: PMC6583191] [
PubMed: 30128538]
- 11.
Silverman ME. Community: the key to building and extending engagement for individuals with aphasia.
Semin Speech Lang. 2011 Aug;32(3):256-67. [
PubMed: 21968561]
Disclosure: Aninda Acharya declares no relevant financial relationships with ineligible companies.
Disclosure: Michael Wroten declares no relevant financial relationships with ineligible companies.
