Intro to Neurology (Adams) Flashcards
A 70 yo right handed man has aphasia and right hemiparesis for the last 2 hours. He has a past history of atrial fibrillation. Where and what is the lesion, and how could it have occured?
Where: Left cerebral hemisphere, causing right hemiparesis with language difficulty (think of Broca’s area on the left)
What: 2 hours is consistent with an acute event like stroke
How: With past hx of afib, think embolus
Acalculia is associated with lesions of the parietal and frontal lobes and results in difficulties with performing simple mathematics. Which hemisphere is usually affected?
Left side (dominant hemisphere in most people)
Hemispatial neglect results most commonly from brain injury to the _____ cerebral hemisphere, causing visual neglect of the _____-hand side of space.
right cerebral hemisphere; left-hand (nondominant for most) side of space
*2 other conditions associated with damage to the right side hemisphere include:
- Anosognosia (lack of knowledge of illness)
- Asomatognosia (lack of knowledge of body part)
weakness, hyperreflexia, spasticity, and Babinski sign are indicators of what type of lesion?
upper motor neuron
weakness, hyporeflexia, flaccidity, atrophy, and fasciculations are all symptoms that are typical of what kind of lesion?
lower motor neuron
*fasciculation - spontaneous contraction affecting a small number of muscle fibers, often causing a flicker of movement under the skin
if there is no facial involvement, where is the lesion?
low brainstem or spinal cord
paraparesis - involvement of both legs with arms normal - is indicative of a leison where?
spinal cord
hemiparesis indicates a lesion where?
contralateral brain stem or cerebral hemisphere
True or False: visual loss almost always involves a brainstem lesion.
False. You cannot have visual loss with a brainstem lesion, as lesions must involve the optic nerve, chiasm, tract or cerebral hemisphere - all of which reside above the infratentorium.
what is dissociated sensory loss?
it’s the term used to describe the pattern of selective modality loss with any given lesion - this is due to 2 sensory systems that send information up to the cortex: the spinothalamic, which relays pain and temperature sensation, and the dorsal columns, which conduct vibratory and position sense.
though incoordination/ataxia may result from motor or sensory impairments, lesions of what structure typically result in these deficits?
cerebellum
Which of the following is a distinct symptom that differentiates lesions in the dominant (vs. non-dominant) cerebral cortex?
A. Contralateral hemiparesis
B. Contralateral hemi-sensory loss
C. Contralateral visual field loss
D. Mild dysarythria
E. Aphasia
E. All of these signs are attributable to lestions in dominant and non-dominant hemisphere except aphasia. This is characteristic of a dominant lesion hemisphere.
Which of the following is a characteristic symptom of non-dominant cerebral cortex lesion?
A. Apraxia
B. Aphasia
C. Aprosody
D. Acalculia
E. Alexia
Aprosody (lack of variations in normal speech characteristics) is due to a lestion in the non-dominant hemisphere.
*others include:
- anosognosia - deficit of self-awareness
- asomatognosia - loss of recognition or awareness of part of the body
- contralateral hemi-spatial neglect
contralateral sensory loss with or without weakness is the most common pattern of signs for lesions of what structure?
thalamus
*other signs include
- abnormal ocular motility (vertical gaze)
- disturbed consciousness/sleep-wake cycle
- behavioral or cognitive impairments
isolated cranial nerve III palsy is most likely due to a lesion inside or outside the CNS?
outside. if it were in the brainstem there would be other symptoms to help with the diagnosis.
name two examples of cranial nerve mononeuropathy in which there would be sensory/motor loss on the affected side
Bell’s palsy (VII)
Trigeminal neuralgia (V)
features of this type of lesion include diplopia, incoordination, tremor, waxing-and-waning consciousness, weakness and numbness
midbrain lesion
*much less common than medullary or pontine lesions
what are the 2 major signs associated with midbrain lesions?
- CN III and IV palsies
- Internuclear ophthalmoplegia - disorder of conjugate lateral gaze in which the affected eye shows impairment of adduction
features of these types of lesions may be bilateral or unilateral, and include coma, weakness of all limbs (when involvement is bilateral), dysphagia, dysarthria, diplopia (when involvement is unilateral)
pontine lesions
clinical signs of lesions in this area include:
- ipsilateral signs of ataxia, nystagmus, facial sensory loss, and CN XII dysunfction
- contralateral signs of limb sensory loss and hemiparesis
medulla
which of the following cerebellar locations: lesion signs is incorrectly matched?
A. Floccular-nodular: visual defecits
B. Vermis-paravermian: truncal ataxia
C. Hemisphere: vestibular deficits
D. pan-cerebellar: all signs above
C. Vestibular defecits go with floccular-nodular lesions. Cerebellar hemisphere lesions can produce classic ipsilateral limb ataxia (intention tremor, past pointing and mild hypotonia).
clinical features of this spectrum of diseases reflect the function of the spinal cord: abnormal gait, dermatomal sensory loss, motor problems (including +Romberg sign), weak rectal sphincter and orthostatic hypotension
myelopathies
progressive weakness of the limbs with no autonomic or sensory symptoms, possibly with fasciculations in “asymptomatic” areas are findings of what group of diseases?
neuronopathies (ie, ALS)
neck and back pain with pain, paresthesia, numbness and weakness that refers to limbs in a dermatomal pattern is characteristic of what group of diseases?
radiculopathies
*may be caused by herniated disk, injury or tumor at the level of the nerve root after it leaves the spinal cord.
