Flashcards in Neuro Deck (38):
Which vessel is most commonly affected by cerebrovascular accidents?
the MCA (middle cerebral artery)
What structures does the MCA supply?
--Lateral surfaces of the frontal, parietal and upper temoral lobes
--the internal capsule
--most of the basal ganglia
What symptoms would be expected with occlusion of the MCA?
--aphasia (e.g., Broca's or Wernicke's) if the stroke occurred in the language-dominant hemisphere (usually left)
--Hemineglect if the stroke occurred in the non-dominant hemisphere (usually right)
--anesthesia of the contralateral face and upper limb
--Spastic paresis of the contralateral lower face and upper limb.
Describe Broca's aphasia
characterized by slow, nonfluent speech with deficits in word-finding. Because **comprehension is normal**, patients are able to follow commands, they are typically aware of the problem, and can be frustrated.
Repetition, writing, and reading aloud is often impaired, but reading comprehension is often preserved.
Describe Wernicke's aphasia
Speech is nonsensical but fluent (word salad), and the patient as a lack of both comprehension and awareness of his or her syndrome.
What symptoms would arise from occlusion of the ACA?
spastic paralysis and anesthesia (loss of sensation) of the contralateral lower limb.
urinary incontinence may be present (usually present with bilateral damage)
What does the posterior cerebral artery (PCA) supply?
--part of the temporal lobe
How does occlusion of the PCA present?
with a homonymous hemianopia of the contralateral visual field with macular sparing
What artery supplies the lateral medulla?
The PICA (posterior inferior cerebellar artery)
What syndrome is caused by occlusion of the PICA?
Wallenberg syndrome (lateral medullary syndrom)
How does Wallenberg syndrome present?
--Ipsilateral limb ataxia
--ipsilateral loss of pain and temperature sense from the face
--contralateral loss of pain and temperature sense of the body
--ipsilateral Horner's syndrome
--nausea and vomiting
"Don't pick a (PICA) horse (hoarseness) that can't eat (dysphagia)
How would a lesion of the trigeminal nerve present?
--Ipsilateral loss of sensation to the face (anesthesia of the ipsilateral face)
--The trigeminal nerve (V1) is also the afferent limb of the corneal reflex, which would also be impaired.
What is the corneal relfex?
Involuntary bilateral blinking of the eyelids after stimulation of the cornea
What are the histopathologic features of Alzheimer's Disease?
(1) neurofibrillary tangles consisting of hyperphosphorylated tau protein
(2)extracellular senile plaques consisting of A-beta amyloid
(3) Granulovacuolar degeneration and Hirano bodies
What are Hirano bodies?
rod-shaped, crystal-like and eosinophilic intracellular aggregates of actin
When would we see gliosis of the caudate nucleus?
In Huntington disease
What are the histologic features of Parkinson's disease?
(1) Lewy bodies
(2) loss of pigmented neurons
Lewy bodies are eosinophilic intracytoplasmic spherules
The pigmented neurons are found in the substantia nigra
What is the most common non-glial brain tumor in children?
From what structure does a craniopharyngeoma arise?
From epithelial rests (remnants) derived from Rathke's pouch.
What tumors can lead to bitemporal hemianopia, and how?
Pituitary adenomas and craniopharyngeal tumors can lead to bitemporal hemianopia by compressing the optic chiasm
What HLA haplotype is associated with MS?
What are the most important clues in a patient case for MS?
--well-circumscribed, demyelinated plaques seen on MRI (or autopsy)
--Relapsing-remitting pattern of neurologic symptoms (motor and sensory) that are separated in time and space
Where is the most common site of encephalocele?
the occipital bone
Presentation of a lesion to the optic chiasm
Cause of a central scotoma
Lesions of the retina that include damage to the macula
-neurotoxins, such as ehtambutol
-optic neuritis (and therefore, MS could be a cause of central scotoma)
What is the macula?
An oval region near the center of the retina that is approximately 3mm by 5mm and contains the fovea. It is responsible for central, high resolution vision.
Hypoglossal nerve innervation
intrinsic muscles of the tongue:
genioglossus, hypoglossus, and styloglossus
Lesion of what nerve would be responsible for hoarseness?
The recurrent laryngeal nerves
From what cranial nerve does the recurrent laryngeal nerve branch?
What does the recurrent laryngeal nerve innervate?
All intrinsic muscles of the larynx, except the cricothyroid
What is the connection between thyroidectomy and development of hoarseness?
The right and left recurrent laryngeal nerves ascend to the larynx by passing between the trachea and the esophagus, in close proximity to the thyroid gland. The recurrent laryngeal nerves are therefore particularly susceptible during thyroid surgery.
Motor innervation of the glossopharyngeal nerve
The stylopharyngeus muscle and the parotid gland
Afferent innervation of the glossopharyngeal nerve
visceral afferents and somatosensory
visceral afferents supply:
--carotid sinus baroreceptors
--carotid body chemoreceptors
--mediate taste from posterior 1/3 of the tongue
--supply pain, temperature, and touch information from the posterior 1/3 of the tongue
Facial nerve innervation
--muscles of facial expression
--lacrimal, submandibular and sublingual glands
--mediates taste sensation from anterior 2/3 of the tongue
--Failure of closure of the caudal portion of the neural tube
--Only the meninges herniate through a defect in the vertebral column and form a sac-like structure filled with CSF.
--Meningiocele is typically associate with only minial neurologic damage and is relatively easy to treat surgically.
--Occurs due to failure of closure of the caudal portion of the neural tube.
--Include herniation of the spinal cord along with meningeal tissue through a vertebral defect.
--Associated neurologic deficits are usually severe.
--Caused by failure of closure of the neural tube at the rostal end
--Herniation of brain tissue through a bony defect in the skull