neurological diseases pns. nervous system cns – brain, spinal cord pns (links cns to body) –...
TRANSCRIPT
Nervous System
• CNS– Brain, spinal cord
• PNS (Links CNS to body)– Cranial nerves (from brain)
– Peripheral nerves (from spinal cord)
• Autonomic nervous system smooth muscle and cardiac muscle : (PNS and SNS)
• Somatic (voluntary) system – skeletal m.
Cranial nerves
Mnemonics
• “Oh, Oh, Oh, To Touch And Feel Various Girl's Very Angelic Hands”
• Olfactory, Optic, Oculomotor, Troclear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal
• “Some Say Marry Money, But My Brother Says Big Business Makes Money”
NUMBER NAME TYPE KEY FUNCTION
I Olfactory S Smell
II Optic S Vision
III Occulomotor M Eye movement, pupil size, focusing lens
IV Trochlear M Eye movement
V Trigeminal B Sensations – head & teeth; chewing
VI Abducent M Eye movement
VII Facial B Face and scalp movement, salivation, tears, taste
VIII Vestibulococlear S Balance, hearing
IX GLossopharangeal B Tongue movement, swallowing, salivation, taste
X Vagus B Sensory from: GI, respiratory; Motor: larynx, pharynx, parasympathetic,
abdomen and thoracic organs
XI Accessory M Head movement, accessory motor with vagus
XII Hypoglossal M Tongue movement
Neurological Exam
• Attitude, Level of consciousness, Gait– Cerebral cortex, thalamus, hypothalamus
• Cranial Nerves– I (S) Olfactory: SMELL• ether on cotton—will pull away
– II (S) Optic: VISION• follow moving objects; drop cotton ball
Neurological Exam
– III (M), IV (M), VI (M) : look up, down, sideways: strabismus, aniscoria (PNS/SN)• Oculomotor: Eye movement, pupil size, focusing lens• Trochlear: Eye movement• Abducent: Eye movement
– V (B) Trigeminal: sensory to face, motor to mastication (Chewing); • anesthesia to face, weakness in jaw muscles. • Head and teeth e.g dropped jaw
Neurologic Exam
–VII (M) Facial: Face/Scalp, salivation, tears, taste • unilateral droop; drool; no
menace• Paralysis: eyelid, lip, ear
–VIII (S) Vestibulocochlear: • balance (nystagmus, head
tilt, circling); deafness
Neurologic Exam
– IX (B), X (B), XI (M): swallowing (9 and 10); muscle atrophy • Glossopharyngeal: tongue movement, swallowing,
salivation, taste, dysphagia• Vagus: Sensory: GI/resp; Motor: larynx, pharynx,
parasympathetic, abdomen and thoracic organs. Dysphagia. Megaesophagus. • Accessory: head movement, accessory motor with
vagus. Laryngeal paralysis.
–XII (M) Hypoglossal • loss of tongue movement; unilateral atrophy
Female Brain
Male Brain
Neurologic Exam
• Observe– Mentation (alert,
lethargic, coma, etc)• Agitation, anxiety
• Seizures
– Posture (Higher center)• Upright or sternal
• Head tilt (vestibular?VIII)
• Wide based stance (ataxia, weakness)
Neuro Exam
• Gait– Walking and running on flat, nonslippery surface
• Walk slowly back and forth with turns and circles
– Proprioceptive deficits – knuckling? (spinal cord defect)
– Paresis (Deficient)/paralysis (No) – cerebral cortex, brainstem, spinal cord or peripheral spinal nerves or muscles
– Circling/pacing – • Tight circling with head tilt – vestibular (VIII)
• With dementia – ipsilateral cerebral cortex
Posterior Paresis (T-L)
• Reflexes presentin the rear legsT3-L3• Reflexes arediminished orabsent in the rear legsL4-S2•IVDD/Trauma
‘My dog is draggin’
Neuro Exam
– Ataxia/incoordination – cerebellum (coordinates motor activity), vestibular system, or spinal cord
– Dysmetria - cerebellar• Hypermetria – too long movements
• Hypometria – movements too short
Neuro Exam
• Postural reactions– Knuckling– Hopping– Wheelbarrowing– Hemiwalking
• Muscle Tone– Atrophy – occurs slowly from disuse
• Rapidly from nerve damage– LMN – decreased– UMN – extensor muscle tone increased– Test by flexing/extending joints
Knuckling
Neuro exam – Spinal Reflexes• Thoracic limb withdrawal – pinch toe• Patellar – strike patellar ligament – extension of stifle• Pelvic limb withdrawal – pinch toe • Sciatic – Strike between greater trochanter and
ischium – flexion of stifle and hock• Cranial tibial – strike cranial tibial m just below
proximal end of tibia – flex hock• Perineal – pinch perineum/anus – anal sphincter
contraction, tuck tail• Panniculus – stimulate skin over dorsum just lateral
to vertebral column – twitch of cutaneous trunci m.
Patellar Reflex
Reflex examination
• http://www.youtube.com/watch?v=NFqFABsIa7Q&feature=related
Pelvic Limb Withdrawal – Or Not
Panniculus Test
Palpebral reflex
• http://video.google.com/videosearch?q=neurological+exam+in+dogs&hl=en&emb=0&aq=f#
Neuro Exam – Summary UMN vs LMN
UMN LMN
• Muscle tone N or I D
• Spinal reflexes N or I D
• Motor fxn Spastic Flaccid
• Muscle atrophy Mild Severe
• disuse neuro
• Bladder Tense Flaccid
Neuro Exam – Cranial Nerves
• Blind II• No menace II/VII• Anisocoria II, III• Atrophy of temporal V
Muscles• Dropped jaw V• Nares, lip pinch, cornea V
– Inside ear• Lip/ear droop VII• No blink VII• Head tilt VIII
Neuro exam – Cranial Nerves
• Nystagmus VIII
• Deafness VIII
• Difficulty swallowing IX, X
• Loss of gag reflex IX, X
• Laryngeal paralysis IX, X
• Weakness, assymmetry XII– Of tongue
Cranial nerve
• http://www.youtube.com/watch?v=S8f9-GPW9IE&feature=related
The Nervous System
And its associated diseases
Diseases of Brain: Trauma
Dog skull and brain2º Trauma: edema, hemorrhage
1º Trauma—Direct trauma to (↑ intracranial pressure) brain tissue
Brain Trauma
• Signs:– Seizures
– Blood in eyes, ears, nose, oral cavity
– Loss of consciousness or decrease in response to external stimuli
– Shock, coma, altered respiratory patterns
• Dx– Hx of trauma (HBC, falling)
– Chem. panel to rule out other metabolic diseases
Brain Trauma
• Treatment—aimed at reducing 2° effects (edema)– Osmotic agents: Mannitol (20-50%) IV slow bolus
– Diuretics: Furosemide IV q4h
– Anti-seizure Rx if needed: Diazepam, Phenobarbital
• Client info– Some brain injury is irreversible
– Dog in coma >48 h usually does not survive
– Worsening neuro signs → bad prognosis
Idiopathic Vestibular Disease
• Signs– Loss of balance
– Head tilt
– Nystagmus
– Disorientation
– Ataxia
– Vomiting/anorexia
Signalment: Dogs (middle aged) and cats, acuteSignalment: Dogs (middle aged) and cats, acute
IVD: NYSTAGMUS
Click for video
Idiopathic Vestibular disease
http://www.youtube.com/watch?v=ZccUdSH91zc&feature=PlayList&p=E13C63C661759E7C&playnext_from=PL&playnext=3&index=30
http://www.youtube.com/watch?v=Y25T7dZ77T4&feature=related
http://www.youtube.com/watch?v=HjwGY2vJk0E&feature=related
IVD: Ataxia
Click for video
Idiopathic Vestibular Disease
• Dx– Clinical signs
– Blood work to r/o other diseases of nervous system
– Ear exam to r/o inner ear infection
• Rx– Treatment is not recommended; does not alter course of
disease (antibiotics, steroids often given to cover possible causes not found by PE and lab work)
– Clinical signs resolve in 3-6 wks
PEOPLE“The man who smiles in the face of
trouble…
Has found someone to blame it on.”
References
• Alleice Summers, Common Diseases of Companion Animals
• http://neuro.vetmed.ufl.edu/neuro/courses/vem5171/Neuropharmacology.pdf