lower motor neuron dysarthria

Etiology: 1) weakness or paralysis of the articulary muscles 2) lesions of the motor nuclei of the pons & medulla 3) lesions of the cranial nerve 5, cranial nerve 7, cranial nerve 10, or cranial nerve 12 Epidemiology: less frequent than spastic dysarthria Clinical manifestations: 1) in advanced forms, the tongue is shriveled & lies fasciculating on the floor of the mouth 2) lips are lax & tremulous 3) saliva constantly collects in the mouth because of dysphagia 4) drooling is troublesome 5) the voice is altered to a monotone because of vocal cord paralysis 6) as the condition develops, speech becomes slurred & progressively less distinct 7) a special difficulty in the enunciation of r occurs early 8) as paralysis becomes more complete, consonants are not pronounced at all 9) bilataleral paralysis of the palate causing nasality of speech - diphtheria, polio, progressive bulbar palsy 10) bilateral paralysis of the lips - Guillain-Barre syndrome

References

Principles of Neurology, 4th ed, Adan RD & Victor M (eds) McGraw-Hill, Inc, New York, 1989, pg 390