Progressive Aphasia Overview

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Progressive Aphasia (PA) is a language disorder. There are two types of progressive aphasia: fluent PA (called Semantic Dementia (SD)) and non-fluent PA (also called Progressive Non-Fluent Aphasia (PNFA).

The presenting feature in people with PNFA is a deterioration in their ability to produce speech. These patients first become hesitant in their speech, then begin to talk less, and eventually become mute. Current research suggests that the fundamental loss in PNFA is a deterioration in knowledge of the grammatical organization of language; patients are said to have a grammatical processing deficit. This is manifested in the fact that patients have more difficulty understanding complex sentences than simple ones, and retain understanding of single words longer than they do the meaning of those same words when put together in a sentence.

Unlike other FTD subtypes, PNFA does not produce changes in behavior or personality until much later stages of the disease: most people with progressive aphasia maintain the ability to care for themselves, keep up outside interests and, in some instances, remain employed for a few years after onset of the disorder.


Key Clinical Features

* Aphasia is experienced as hesitant, effortful speech. Despite this difficulty, it appears that patientsÂ’ ability to comprehend what others say is preserved longer (though this is eventually lost, as well)
* Dysarthria (increased difficulty producing speech due to weakness or incoordination – speech sounds weak, imprecise and uncoordinated)
* Word meaning is preserved during early stages of the disorder
* Reading and writing abilities may be preserved longer than speech, but these eventually decline, as well.
* Dysphagia (difficulty swallowing)
* Mutism eventually develops with progression
* Neuroimaging Studies demonstrate decreased neural activity and decreased blood flow, especially in the left hemisphere of the frontal and temporal lobes.

In later stages, clinical features may include ones found more commonly in other FTD subtypes. These include:
* Behavioral Symptoms
* Emotional Symptoms
* Neurological Symptoms
* Psychiatric Symptoms
* Cognitive Symptoms


Key Pathologic Features

It is important to note that Progressive Aphasia is a clinical diagnosis, defined by the symptoms the patient displays. There is no single pathology (meaning a specific physical finding in the brain) associated with the clinical disorder known as PNFA. Indeed, upon autopsy, a variety of pathological features have been found in the brains of PNFA patients, many of which are associated with other FTD subtypes. These include: the inclusions seen in nerve cells (Pick bodies) characteristic of PickÂ’s disease; nerve cell loss in the cerebral cortex and basal ganglia seen in Corticobasal Degeneration; and Dementia Lacking Distinctive Histopathology (DLDH), which is a pattern of neural damage seen in several types of FTD. DLDH is characterized by neuronal loss, gliosis (overgrowth, or development of tumors), and spongiosis (swelling with excess fluid).

In patients for whom language dysfunction is the most severe feature, it is common to see cells in the temporal lobe most affected by these disease changes.


Cause

Scientists have recently linked DLDH to abnormally low levels of the protein tau.


Genetics

The majority of PNFA is not hereditary.


Treatment

There is no cure for PNFA.


Management and Prognosis

Speech therapy and voice devices may be effective in preserving some ability for spoken language, at least for a while.

Some PNFA patients develop the behavioral, social, and/or motor complications seen in other forms of FTD. In these patients, prognosis is obviously poorer, and management more complicated. Patients who do not develop these additional symptoms are able to preserve their independence and active lifestyle for a longer period of time.


taken from aphasia.org
Acknowledgement and thanks to NAA Executive Board members Martin Albert,MD,PhD, Harold Goodglass, PhD and Stephanie Mensh for the preparation of this fact sheet.

For additional information and support:
National Aphasia Association
350 Seventh Avenue, Suite 902
New York, N.Y. 10001
naa@aphasia.org
http://www.aphasia.org
Tel: 800-922-4622

Material prepared by Jennifer M. Farmer, MS, CGC, Website Clinical Consultant and Susan L-J Dickinson, MS, CGC, Website Medical and Science Writer.