Aphasia and Dysphagia

Aphasia and dysphagiaare language associated conditions. Aphasia is a total disruption of understanding and forming language. Specific regions of the brain control the understanding, written and spoken language. Frontal lobe and temporal lobe of the brain contains two of these key areas. The area close to the left temporal lobe in the pre-motor cortex of the left frontal lobe is the Brocha’s area. Damage to this area disrupts speech production. This is called expressive aphasia because the patients can understand speech well enough. Only verbal expression is disordered. They produce very short meaningful phrases with great difficulty. Often they know of their mistakes and are frustrated by it.There is a right sided weakness in patients with expressive aphasia because the same brain area is important for controlling movements of the right side of the body too.

An area on the temporal lobe close to the parietal lobe is called Wernicke’s area. This area is responsible for understanding spoken and written language. Damage to this area causes receptive aphasia. This is called receptive aphasia because the patients can formulate sentences without any grammatical errors, but they cannot convey the meaning. Only the reception of meaning is disordered, but their expression is normal. Understanding written and spoken language is very difficult for them. They tend to add unnecessary words into sentences and create new words. They are usually unaware of their mistakes. These people do not have associated body weakness due to the Wernicke’s area is nowhere near the areas responsible for gross motor functions.

Conduction aphasia is a rare form of aphasia. Patients cannot repeat what was specifically said, but understanding, talking, and writing are normal. Trans cortical motor aphasia is due to damage to the anterior superior frontal lobe. Patients have very short halting speech with good language understanding. Essentially, its symptoms are similar to expressive aphasia except for normal repetition ability. Stroke is the common cause of this aphasia. Trans cortical sensory aphasia has close symptoms as receptive aphasia, except for normal repetition ability. Anomic aphasia features a total disruption of naming. Global aphasia includes both expressive and receptive disorders.

Aphasia occurs mainly due to brain injury, brain tumour and viral infections like encephalitis. It is also seen in cases of stroke and in degenerative diseases like Alzheimer’s disease and Parkinson’s disease.

Dysphagia is caused due to diseases of the oesophagus like Stricture (narrowing),  Diverticula ,Oesophageal spasms, cancers etc. Oesophagus is a muscular tube that moves food from back of the mouth to the stomach. It is also caused due to defects in the nerves and muscles that control swallowing which occurs in cases of head injury, Stroke, Multiple sclerosis, Parkinson’s disease and after an attack of Polio (viral infection causing paralysis). The only difference between aphasia and dysphasia is Aphasia means a total disruption while dysphasia means a moderate disruption.

Tests like MRI and CT scan help to identify the cause of aphasia. The speech-language pathologist assesses the individual and determines the type of aphasia. To determine the cause of dysphagia, the tests done include barium X-ray, CT scan, Endoscopy, and Chest X-ray.