Neuro4 Flashcards
What is the classic triad of symptoms associated with Horner syndrome?
(1) ptosis (drooping of the eyelid; superior tarsal muscle)
(2) miosis (pupil constriction)
(3) anhydrosis (absence of sweating) and flushing of affected side of the face
How many neurons are involved in the pathway from the hypothalamus to the eye that is involved in horner syndrom? what is the pathway?
3
1st - hypothalamus to intermediolateral column of spinal cord (lateral horns)
2nd - lateral horns to superior cervical ganglion
3rd - ganglion to :
(a) pupil
(b) smooth muscles of eyelid
(c) sweat glands of forehead and face
**the 2nd neuron is the preganglionic sympathetic neuron; the 3rd neuron is the postganglionic neuron
Above what level would we expect a lesion to cause Horner syndrome?
Horner syndrome is associated with a lesion of the spinal cord above T1
What information does the ophthalmic division of the trigeminal nerve carry? (V1)
(5 places)
V1 carries sensory information from:
- -the scalp and forehead
- -upper eyelid
- -conjunctiva and cornea (corneal reflex)
- -the nose and nasal mucosa
- -the frontal sinuses
What fibers does the oculomotor nerve carry with it?
- -motor efferents that innervate most of the extraocular eye muscles
- -parasympathetic preganglionic fibers that synapse on the postganglionic nerves in the ciliary ganglion. (These will synapse on the pupillary sphincter muscle
What is the organization of fibers in the oculomotor nerve?
The motor efferents are located centrally, and the parasympathetic preganglionic fibers are located peripherally
(Motor-Medial, Parasympathetic-Peripheral)
How would a lesion of the oculomotor nerve present?
- -mydriasis
- -loss of direct and consensual pupillary light reflex
- -loss of accommodation and convergence
- -loss of extraocular eye movement, adduction in particular –> diplopia on horizantal gaze
Hemifacial anesthesia would result from lesion to what?
Trigeminal
Hemifacial anhydrosis would result from lesion to what?
- -Descending hypothalamic fibers, above T1
- -The sympathetic chain (e.g., superior cervical ganglion)
Hemifacial weakness would result from lesion to what?
Facial nerve
Can INO (internuclear opthalmoplegia) be a symptom of an oculomotor nerve palsy?
No. INO is a specific diagnosis; it is caused by lesion of the medial longitudinal fasciculus (MLF), which formed by neuronal axons that extend from the abducens nucleus, decussate, and synapse on the oculomotor nucleus on the opposite side.
INO results in patients who cannot adduct an eye on horizantal gaze –> horizantal diplopia. This is a shared symptom with a CNIII palsy. However, in INO, patients would not have ptosis or pupil abnormalities (mydriasis)
Where is the substantia nigra located?
In the midbrain, between the crus cerebri and the red nucleus
What are the common symptoms associated with Parkinson disease?
TRAPS
Tremor (e.g., pill-rolling tremor) Rigidity ("cogwheel" rigidity) Akinesia (or bradykinesia) Postural instability Shuffling gait
**TRA are the “classic” triad
What is the histopathologic hallmark of Parkinson disease?
–Lewy bodies: round, eosinophilic, intracytoplasmic inclusions seen in dopaminergic nigrostriatal neurons
–loss of dopaminergic neurons (i.e., depigmentation) of the substantia nigra pars compacta
What are Lewy bodies composed of?
alpha-synuclein
What two diseases are associated with Lewy bodies?
(1) Parkinson disease
(2) Lewy body dementia
How can Lewy body dementia and Parkinson disease be differentiated clinically? (3)
(1) Dementia is a common feature late in the disease in Parkinson’s, whereas early-onset dementia is suggestive of Lewy body disease.
(2) Lewy body disease is also characterized by hallucinations (not present in Parkinsons)
(3) cortical Lewy bodies present in Lewy body disease (only found in substantia nigra in Parkinson’s)
What histologic feature is associated with Creutzfeldt-Jakob disease (CJD)?
spongiform changes
Adult Polycystic Kidney Disease
Autocomal dominant genetic disorder characterized by bilaterally enlarged kidneys with multiple cyts.
Associated with Berry aneurysms in the circle of Willis, which can bleed and produce a subarachnoid hemorrhage
Location of lesion in Wernicke aphasia
superior temporal gyrus
Location of lesion in Broca aphasia
Inferior frontal gyrus
Location of lesion in Conduction aphasia
Arcuate fasciculus
Type of aphasia?
Fluent: Yes
Comprehends: No
Repeats: No
Wernicke
Type of aphasia?
Fluent: NO
Comprehends: Yes
Repeats: No
Broca