Aphasia vs Dementia
Neurological disorders can manifest from simple memory loss in Alzheimer’s to more aggressive forms like mania and epilepsy. The manifestations depend chiefly on the area of the brain that is affected as every part of the brain has a different function, unlike other organs which essentially have one main function.
Dementia, meaning madness in Latin, implies a serious memory loss in a previously normal person, beyond what is expected due to normal ageing. The memory loss can be classified as static and complete, due to an injury to the brain and progressive, if it worsens slowly over time due to any reason. Aphasia, means speechlessness in Greek and is a manifestation of either disturbed comprehension and/or speech articulation. Depending on the region of the brain that is damaged, it can range from having problems in recollecting and using the correct word at the right time, to not being able to speak at all and even not being able to write what you wish to express.
Causes of dementia are hypothyroidism, vascular events, Alzheimer’s, Huntington’s disease, traumatic head injury, stroke, meningitis, chronic alcoholism leading to Wernicke’s encephalopathy and Korsakoff’s psychosis. Aphasia most commonly is the result of a stroke or traumatic injury to the skull. Brain tumors and infections may also precipitate a gradually evolving aphasia. The kind of aphasia will be determined by the area of the brain involved.
Aphasia can be classified as expressive aphasia, receptive aphasia, anomic aphasia, global aphasia, conduction aphasia and 3 transcortical type aphasias based on symptoms like repetition, fluency of speech, ability to name, etc. Symptoms of aphasia vary vastly; persistent phrase repetition, inability to read aloud, inability to repeat/write, disability in naming objects or recollecting their names, substitution of words/letters, speaking complete gibberish are all symptoms of aphasia. Symptoms of dementia can be permanent or transient. There might be transient memory loss after a seizure or acute head injury, which returns spontaneously over few hours/days. Permanent dementia is seen in conditions like Alzheimer’s, Parkinson’s and stroke. Dementia manifests as difficulty in recalling past experiences, retaining new information, loss of feeling and thoughts. People might forget to do daily activities like brushing and bathing and start neglecting themselves. There might be sudden outbursts of emotions like crying or anger without any apparent cause.
Diagnosis of both aphasia and dementia is by observing the symptoms. There are no particular tests which give conclusive evidence of either. Brain imaging techniques like CT scan, MRI might help by identifying damaged tissue in the brain. There exist 5-15 minute long tests that are reasonably reliable in screening dementias like MMSE and AMTS which are conducted by specialists.
There is no real cure for dementia and aphasia. If the cause is a tumor, then removing it might solve the condition but not necessarily. A few dementias are treatable, e.g. if due to hypothyroidism, or due to meningitis, correcting the cause returns the dementia to normal. Similarly, no single treatment can be applied for aphasia. Using speech therapists, occupational therapists, physiotherapists and neuropsychologists, aphasia can be worked on to improve but cure is rare.
Take home pointers:
Aphasia is speechlessness while dementia is serious memory loss in a previously normal person.
Aphasia can manifest as inability in reading, writing, talking, naming, identifying objects, recalling names, etc.
Dementia manifests as difficulty in recalling experiences, retaining new information, not being able to identify friends and relatives, forgetting daily hygiene rituals, wandering aimlessly and sudden emotional outbursts.
Diagnosis is chiefly by symptoms, few tests might aid an anatomical diagnosis.
Treatment for a few dementias is available, remaining are incurable. Aphasias require multiple modalities of treatment for improvement but a cure is rare.