Dysarthria of Speech and Associated Speech Disorders
Speech disorders in a person or due to a change in anatomy the brain suffers due to a stroke, trauma or injury. Dysarthria of speech and other associated disorders like cerebellar speech, dysphasia and extrapyramidal speech are caused due to the effect on various specific anatomies of the nervous system. Every speech disorder has its own localised area in the brain and an abnormality in a particular anatomy in the brain causes the disorder.
Dysarthria of Speech: A person suffering from the speech disorder dysarthria would be possessing lesions in any of the following organs.
End Organs: The end organs are the tongue and mouth. The muscles of the tongue and mouth if are affected with lesions, would lead to immense pain and cause difficulties in speech.
- Also, lesions would lead to swallowing problems there by obstructing the speech.
- Tongue hypertrophy (increase in the tongue’s volume or size due to cell enlargement) due to myxedema (a tissue related disease) could cause dysarthria.
- Also, facioscapulohumeral (a very common genetic disorder) of the facial muscles can also lead to dysarthria.
Peripheral Nerve: A damage to the following peripheral nerves can also cause dysarthria.
When a person suffers from trauma the hypoglossal nerve (nerve responsible for tongue’s movement) could be affected with lesions.
Trigeminal nerve (responsible for facial sensations) could be pressurised during trauma or a surgery that can give rise to lesions.
Brainstem: The lesions viz.,
- poliomyelitis (a viral infection, widely known as polio)
- disseminated encephalomyelitis (a brain disease similar to multiple sclerosis)
- occlusions in the basilar artery
- brainstem gliomas (tumours in the brain stem)
- Guillian-Barre syndrome (autoimmune disorder of the peripheral nerves)
can cause dysarthria.
Cerebellar Speech: Multiple sclerosis, tumours in the cerebellum, cerebellar ataxis ( a neurological disorder that lead to lack of muscle coordination) and atrophy of alcoholic cerebellum are the condition that cause this speech disorder.
Dysphasia: In this condition, patients would find it difficult to find words during speech or produce unclear and incoherent speech. Lesions in the cerebrum would lead to dysphasia.
Extrapyramidal Speech: The speech is usually jerky or would sound disrupted. The conditions that lead to this speech disorder are Wilson’s disease (a genetic disorder that can cause psychiatric disorders) and Huntington Chorea (disorder of the central nervous system).
Dysarthria of speech and other associated speech disorders need the proper diagnosis so as to locate the area in the brain that’s been affected.