Neurologically Based Communication Disorders

Differentiating the six Dysarthrias

Type Site of Lesion Possible Causes Primary Speech Characteristics
Flaccid Lower Motor Neuron Viral Infection,
Tumor,
CVA,
Congenital Conditions,
Disease,
Palsies,
Trauma
Hypernasality,
Imprecise Consonants,
Breathiness,
Monopitch,
Nasal Emission
Spastic Upper Motor Neuron Tumor,
CVA,
Congenital Conditions,
Infection,
Trauma
Imprecise Consonants,
Monopitch,
Reduced Stress,
Harsh Voice Quality,
Monoloudness,
Low Pitch,
Slow Rate,
Hypernasality,
Strained-strangled Voice,
Short Phrases
Mixed
(Flaccid and Spastic)
Upper & Lower Motor Neuron Amyotrophic Lateral Sclerosis,
CVA,
Trauma
Imprecise Consonants,
Monopitch,
Distorted Vowels,
Harsh Voice Quality,
Monoloudness,
Low Pitch,
Slow Rate,
Hypernasality,
Excess & Equal Stress,
Short Phrases,
Prolonged Interval
Ataxic Cerebellar System Tumor,
CVA,
Congenital Conditions,
Infection,
Trauma,
Toxic Effect
Imprecise Consonants,
Excess & Equal Stress,
Irregular Articulatory Breakdowns,
Distorted Vowels,
Harsh Voice,
Loudness Control Problem,
Variable Nasality
Hypokinetic Extrapyramidal System Parkinsonism,
Drug-Induced
Imprecise Consonants,
Monopitch,
Monoloudness,
Reduced Stress,
Harsh Voice,
Inappropriate Silences,
Short Rushes of Speech
Hyperkinetic Extrapyramidal System Chorea,
Infection,
Gilles de la Tourettesyndrome,
Ballism,
Athetosis,
CVA,
Tumor,
Dystonia,
Drug-Induced,
Dyskinesia
Imprecise Consonants,
Distorted Vowels,
Harsh Voice Quality,
Irregular Articulatory Breakdowns,
Strained-strangled Voice,
Monopitch,
Monoloudness

The Cranial Nerves – Types and Functions

Nerve Type Function
I Olfactory Sensory Smell
II Optic Sensory Vision
III Oculomotor Motor Movement of Eyeball, Pupil, Upper Eyelid
IV Trochlear Motor Movement of superior oblique eye muscles
V * Trigeminal Mixed Tactile facial sensation, movement of muscles of chewing
VI Abducens Motor Open the eyes
VII * Facial Mixed Taste, movement of facial muscles
VIII * Acoustic Sensory Hearing & Equilibrium
IX * Glossopharyngeal Mixed Taste, gag, elevation of palate and larynx for swallow
X * Vagus Mixed Taste, elevation of palate, movement of pharynx and larynx
XI * Accessory Motor Turn Head, shrug shoulders, movement of palate, pharynx and larynx
XII * Hypoglossal Motor Movement of tongue
* Indicates nerves that are most directly related to speech, language, swallowing or hearing.