Anatomical Basis of Neural Deficits Flashcards
peripheral deficits
- are defined by?
- include which categories of disorders:
- definition: defect of a peripheral nerve (including roots) that go out to an effector organ
- include
- muscle defects
- neuromuscular defect
- peripheral nerve defect
- nerve root defect (ridiculopathy)
muscle type peripheral defect
- presents what key sx?
- does NOT present with what key sx?
motor weakness without sensory impairment
- seen: motor weakness that
- is proximal - esp hip & thigh
- is symmetrical
- initially mild, then worsens from prox -> distal
- presents as trouble rising (climbing stairs, standed from seat)
- not seen: sensory impairment ( numbness / weakness)
neuromuscular type peripheral defect
- presents what key sx?
- does NOT present with what key sx?
motor weakness + fatigue without sensory impairment
- seen: motor weakness that
- is proximal - esp hips & thigh
- is mild / absent throughout course
- is largely presents as fatigue
- no seen: sensory impairment (pain / numbness)
compare & contrast muscle vs neuomuscular peirpheral deficits
- motor weakness without sensory deficits:
- muscle: progressses from mild to worse, limits rising - on stairs / from a chair
- neuromuscular: remains mild, presents as fatigue
periperhal nerve type peripheral defect
- presents what key sx?
- does NOT present with what key sx?
muscle weakness following sensory impairment
-
muscle weakness that is
- distal
- assymetric
- characterized by hyporeflexia, hypotonia
- matched to paraesthesia distribution
- sensory impairment (numbness) that - prededes weakness
nerve root (ridiculopathy) type peripheral defect
- presents what key sx?
- does NOT present with what key sx?
pain +/- weakness
-
pain that
- is shooting / stabbing
- radiates from the spine outwards
-
muscle weakness that
- does not effect tone
muscle deficits include what major disorders?
- muscular dystrophies
- polymyositis
- thyroid disorders
- toxin exposures
neuromuscular deficits include what major disorders?
- myasthetnia gravis: rapid fatigue with quick recovery upon rest
- eaton lambert syndrome: fatigue followed by strength improvement with exercise
- extraocular muscles - ptosis, nystagmus
peripheral nerve deficits include what major disorders?
- mononeuropathy
- polyneuropathy
nerve root deficits (radiculopathy) include what major disorders?
- sciatica (L5/S1)
- upper extremitiy radiculopathy (C5/C6)
myasethenia gravis
- cause
- presentation
- neuromuscular type (ACh deficient) perpheral disorder
- presentation: rapid fatigue, but followed by quick recovery upon rest
eaton lambert syndrome
- cause
- presentation
- neuromuscular type (ACh deficiency) peripheral disorder
- presentation: fatigue that wanes as strength improves with exercise
mononeuropathy
- cause
- presentation
- cause: peripheral nerve type peripheral defect - nerve entrapment / impairment often d/t
- trauma
- surgery
- presentation: sensory loss distal to point of impingement
- assymetrical
- follows dermatome
peirpheral polyneurophathy
- cause
- presentation
- cause: peripheral nerve type peripheral defect - due to metabolic disorder that disrupts long axons
- diabetes
- guillane barre
- charcot marie tooth
- presentation: sensory loss of distal extemities, symmettrically (“gloves and socks”)
sciata
- cause
- presentation
- nerve root (radiculopathy): due to L5/S1 spinal nerve compression
- presentation: pain that originates in buttocks then -> radiates along posterior thigh
upper extremity radiculopathy
- cause: radiculopathy (nerve root) d/t C5/C6 inervertebral diss
- presentation: pain that radiates along trapezius -> shoulder & can extend all down UE to thumb
what are the major types of spinal deficits?
- transection
- hemisection
- compression
- commisural lesion
- medullary lesion
transection - presentation
= total loss of a spinal level
- below damage, there will be a loss of:
- motor loss (paralysis)
- autonomic function
- propioreception (touch)
- pain + temp two spinal segments below
- reflexes
- normal superior to damage
- absent at spinal level
- exaggerated below damage
hemisection - presentation
= brown-sequard syndrome
- ipsilateral loss of
- motor (corticispinal)
- propioreception / touch (dorsal column)
- contralateral loss of
- pain + temperature (spinothalamic)
compression - presentation
i.e., external presentation of the spinal cord
in this order:
- impairment of bladder then -> bowel
- motor dysfunction
- sensory dysfunction
commisural lesion - presentation
lesion within the central canal that expands to disrupt ventral white commisure (dessucation site of spinothalamic)
- bilateral pain + temperature loss in a single dermatomal pattern
what is the infratentorium?
brainstem + cerebellum
aka posterior fossa
infranteorial medial lesions can endanger what tracts / nuclei?
- corticpinal motor tracts
- medial lemniscus
- medial longitudinal fasciculus
- hypoglossal (XII) nucleus
infratentorial medial lesions can lead to what deficits?
- corticospinal motor tracts: contralateral hemiplagia (motor loss)
- medial lemniscus: contralateral loss of touch / propioreception
- medial longitudinal fasciculus: ipsilateal nystagmus
- hypoglossal motor nucleus: ipsilateral impairment of tongue mobility
infratentorial lateral lesions endanger what tracts / nuclei?
- spinal lemniscus (spinothalamic)
- spinal trigeminal (V)
- spinocerebellar tract
- sympathetic chain
infratentorial lateral lesions can lead to what defecits?
- spinal lemniscus (spinothalamic): contralateral pain + temp loss
- spinal trigeminal (V): facial paresthesia
- spinocerebellar tract: ipsilateral propioreception loss
- sympathetic chain: ipsilateral Horner’s syndrome
the medulla oglongota gives rise to what cranial nerves?
- glossopharyngeal (IX)
- vagus (X)
- accessory (XI)
- hypoglossal (XII)
the pons give rise to what cranial nerves?
- trigeminal (V)
- abducens (VI)
- facial (VII)
- vestibuloacoustic (VIII)
the midbrain gives rise to what cranial nerves?
- oculomotor (III)
- trochlear (IV)
medulla oblongata lesions can lead to what deficits?
- glossopharyngeal (IX): impaired gag reflex
- vagus (X): dysarthria (trouble talking), dysphagia (trouble swallowing)
- accessory (XI): neck weaness
- hypoglossal (XII): palate deviation
pontine lesions can lead to what deficits?
- trigeminal (V): facial parasthesia
- abducens (VI): diplopia, nystagmus
- facial (VII): facial paralysis
- vestibuloacoustic (VIII): deafness
midbrain lesions can lead to what deficits?
- oculomotor (III):dipoplia, nystagmus
- trochlear (IV)
cerebellar deficits can lead to?
(specify differences in LE vs UE)
(infratentorial defciti)
- in general: ataxia - “appear as if drunk”
- LE: gait ataxia - extra wide stance, staggering walk
- UE{ pointing disorders, targetting difficulties, intention tremors
