Final answer:
Neuropathologies such as Alzheimer's disease, Parkinson's disease, ALS, and multiple sclerosis can affect articulation by damaging neurons or disrupting nerve signal transmission. Damage to the brainstem or cranial nerves, as well as acute events like a stroke, can also impair the ability to articulate speech. Neurologists assess these manifestations through neurological exams.
Step-by-step explanation:
Articulation, the process of forming clear and distinct sounds in speech, can be affected by a range of neuropathologies that damage different parts of the nervous system involved in speech production. Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis (ALS) often lead to neuron degeneration, which may impair motor functions necessary for articulation. In Parkinson's disease, for example, the reduction of dopamine can lead to bradykinesia (slowness of movement) and muscle rigidity, affecting speech clarity and voice volume. Other neurological disorders such as multiple sclerosis (MS) may impact myelin, the protective covering of nerve fibers, disrupting the transmission of nerve signals and resulting in speech dysfunctions. Furthermore, localized damage to the brainstem or specific cranial nerves, such as the hypoglossal nerve, can lead to impaired tongue movement, crucial for articulation.
Alongside neurodegenerative conditions, acute events like a stroke or trauma can also result in speech difficulties. These clinical manifestations are often assessed by neurologists through comprehensive neurological exams, which include specific subtests addressing language and speech, to inform diagnoses and tailor treatments accordingly.