Neurophysiology Flashcards
Neurophysiology
The functioning of the nervous system
Trigeminal Nerve
The trigeminal nerve (the fifth cranial nerve, or simply CN V) is a nerveresponsible for sensation in the face and motor functions such as biting and chewing.
Trigeminal Lesions (motor and sensory effects)
Motor:
- Atrophy of the jaw
- Jaw deviates toward side of lesion or weakness
- Open mouth posture
- Weakness or paralysis of the velum
- Hypernasality
Sensory:
•Loss of tactile sensation to anterior two thirds of the tongue
Trigeminal Neuralgia
Chronic pain that affects the trigeminal nerve
Trrigeminal Neuralgia- Typical type (TN1):
Extreme sporadic, sudden burning or shock-like facial pain that lasts anywhere from a few seconds to as long as two minutes per episode.
Trigeminal Nerualgia- Atypical type (TN2):
Constant aching, burning, stabbing pain of somewhat lower intensity than TN1
The facial nerve
The facial nerve is the seventh cranial nerve, or simply cranial nerve VII. It emerges from the brainstem between the pons and the medulla, controls the muscles of facial expression, and functions in the conveyance of tastesensations from the anterior two-thirds of the tongue and oral cavity.
Facial Nerve Lesions
- Articulatory functioning
- Paralysis to muscles of facial expression
- Facial paralysis on the side of the lesion
- Bells palsy may result from any compression of the nerve
Bells Palsy
The glossopharyngeal nerve
The glossopharyngeal nerve, known as the ninth cranial nerve, is a mixed nerve that carries afferent sensory and efferent motor information. It exits the brainstem out from the sides of the upper medulla, just rostral (closer to the nose) to the vagus nerve.
Glossopharyngeal Lesions
- Paralysis of the stylopharngeus muscle
- Loss of general sensation (anesthesia) to posterior one third of the tongue and pharynx
- Reduced or absent gag reflex
The vagus nerve
The vagus nerve (/ˈveɪɡəs/ vay-gəs), historically cited as the pneumogastric nerve, is the tenth cranial nerve or CN X, and interfaces with parasympathetic control of theheart and digestive tract. The vagus nerves are paired; however, they are normally referred to in the singular.
Vagus Lesions
- Loss of gag reflex
- Hypernasality
- Asymmetrical palatal elevation
- Nasal regurgitation
- Laryngeal stridor
- Vocal fold paralysis
Dysphagia
Dysphagia is the medical term for the symptom of difficulty in swallowing. The word is derived from the Greek dys meaning bad or disordered, and the root phag-meaning “eat”.
Not to be confused with Dysphasia
The hypoglossal nerve
The hypoglossal nerve is the twelfth cranial nerve XII, and innervates muscles of thetongue. The name hypoglossus springs from the fact that its passage is below thetongue, hypo meaning “under”, and glossus meaning “tongue”, both of which are fromAncient Greek. The nerve is involved in controlling tongue movements required for speech, food manipulation (i.e. formation of bolus), and swallowing.
Hypoglossal Lesions
- Profoundly affects articulation and speech intelligibility
- Intrinsic and extrinsic muscles of the tongue
- May have fasiculations
Flaccid Paralysis
- Hypotonia and hyporeflexia
- Reduced or absent reflexes
- Low muscle tone
Plegia (3 types)
- Para lower portion of body
- Hemi half of the body
- Quad from the neck down or all 4 extremities
Speech Disorders (6 types)
- Dysarthria
- Apraxia
- Aphasia
- Myasthenia gravis
- Amyotrophic Lateral Sclerosis
- MS
Dysarthria
- Speech disorder arising from paralysis and muscle weakness
- Flaccid – hypotonia and fasiculations
- Spastic – paralysis and hyperflexia and hypertonia
- Ataxic – cerebellum or brainstem, loss of coordination
- Hypokinetic – paucity of movement, Parkinson’s
- Hyperkinetic –extraneous voluntary movements, ballism (uncontrolled flailing)
- Mixed – ALS, combination of many
Apraxia
- Inability to perform sequential and isolated motor movements
- Problem with motor programming and planning for speech and non speech production
- Not due to weakness
Aphasia
Caused by brain damage
- Non fluent –Broca’s-expressive aphasia
- Fluent – Wernicke’s-receptive
Paraphasias
- Verbal – substitute one word for another two types
- Random and semantic
- Random dog for flower
- Semantic same category i.e. mother for father
- Neologistic- entirely new word that is non meaningful i.e. arbuckel
- Phonetic or literal substitutes one sound for another i.e. mandwhich for sandwich
Myasthenia Gravis
- Neuromuscular disease
- Builds antibodies that blocks reception of neurotransmitters
- Extreme fatigue at end of day
- Speech becomes more unintelligible
- Reduced velar functioning is an early sign
- Hypernasal speech
ptosis
drooping eyelid
ALS
- Demyelinating disease of the brain myelin
- Progressive
- Unknown etiology
- 2-5 years from date of diagnosis to death
- 40-50 years of age
Multiple Sclerosis
