Anatomic Localization Flashcards
General principles of lesion: cortex?
Localization in the Upper Motor Neuron (Pyramidal) System
Principle: Tone Is Increased, Causing Spasticity and Hyperreflexia
General principles of lesion: corona radiata?
Localization in the Upper Motor Neuron (Pyramidal) System
Principle: Tone Is Increased, Causing Spasticity and Hyperreflexia
General principles of lesion: internal capsule?
Localization in the Upper Motor Neuron (Pyramidal) System
Principle: Tone Is Increased, Causing Spasticity and Hyperreflexia
General principles of lesion: brain stem?
Localization in the Upper Motor Neuron (Pyramidal) System
Principle: Tone Is Increased, Causing Spasticity
and Hyperreflexia
General principles of lesion: spinal cord?
Localization in the Upper Motor Neuron (Pyramidal) System
Principle: Tone Is Increased, Causing Spasticity
and Hyperreflexia
General principles of lesion: anterior horn?
Localization in the Lower Motor Neuron System
Principle: Tone Is Decreased, Causing Flaccidity
and Hyporeflexia
General principles of lesion: root/plexus?
Localization in the Lower Motor Neuron System
Principle: Tone Is Decreased, Causing Flaccidity
and Hyporeflexia
General principles of lesion: nerve?
Localization in the Lower Motor Neuron System
Principle: Tone Is Decreased, Causing Flaccidity
and Hyporeflexia
General principles of lesion: neuromuscular junction?
Localization in the Lower Motor Neuron System
Principle: Tone Is Decreased, Causing Flaccidity
and Hyporeflexia
General principles of lesion: muscle?
Localization in the Lower Motor Neuron System
Principle: Tone Is Decreased, Causing Flaccidity
and Hyporeflexia
General principles of lesion: midbrain?
Localization within the brain stem
Principle: specific cranial nerve involvement guides localization
General principles of lesion: pons?
Localization within the brain stem
Principle: specific cranial nerve involvement guides localization
General principles of lesion: pontomedullary junction?
Localization within the brain stem
Principle: specific cranial nerve involvement guides localization
General principles of lesion: medial medullar (rare)?
Localization within the brain stem
Principle: specific cranial nerve involvement guides localization
General principles of lesion: lateral medulla (wallenberg syndrome)?
Localization within the brain stem
Principle: specific cranial nerve involvement guides localization
General principles of lesion: hemicord (brown-sequard syndrome)?
Localization in the Spinal Cord
Principle: Localization Is Assisted by the Combination of Tracts Involved
General principles of lesion: anterior cord?
Localization in the Spinal Cord
Principle: Localization Is Assisted by the Combination of Tracts Involved
General principles of lesion: central cord?
Localization in the Spinal Cord
Principle: Localization Is Assisted by the Combination of Tracts Involved
General principles of lesion: posterior cord?
Localization in the Spinal Cord
Principle: Localization Is Assisted by the Combination of Tracts Involved
General principles of lesion: foramen magnum?
Localization in the Spinal Cord
Principle: Localization Is Assisted by the Combination of Tracts Involved
General principles of lesion: conus medullaris?
Localization in the Spinal Cord
Principle: Localization Is Assisted by the Combination of Tracts Involved
General principles of lesion: cauda equina?
Localization in the Spinal Cord
Principle: Localization Is Assisted by the Combination of Tracts Involved
Signs and symptoms of cortex lesion?
signs:
- differential weakness of limbs and face
- sensory symptoms
- language, visual or attentional alterations
symptoms:
- fractionated weakness (e.g. arm greater than face and leg)
- cortical and primary sensory loss
- aphasia, hemianopia, or hemineglect
- cognitive dysfunction
Signs and symptoms of corona radiata lesion?
signs:
- differential weakness of limbs and face
symptoms:
- fractionated weakness
- primary sensory loss
Signs and symptoms of internal capsule lesion?
symptoms:
- weakness only
signs:
-face, arm and leg affected equally and densely
Signs and symptoms of brain stem lesion?
symptoms:
- unilateral or bilateral weakness
- diploplia, vertigo, dysarthria, or weakness
signs:
- dense hemiparesis
- ocular or oropharyngeal dysphagia
- motor posturing
Signs and symptoms of spinal cord lesion?
symptoms:
- difficulty with gait + walking
- urinary incontinence
signs:
- no face involvement
- spastic quadriparesis (cervical) or paraparesis (thoracic)
- sensory level
Signs and symptoms of anterior horn?
symptoms:
- progressive flaccid weaknesses
signs:
- wasting, weakness, fasciculations
- no sensory loss
Signs and symptoms root/plexus?
Symptoms:
- single-limb weakness and sensory loss
- pain in the neck, back or limb
signs:
- weakness in radicular/plexus distribution
- EMG shows denervation in affected muscles
Signs and symptoms of nerve lesion?
Symptoms:
- focal weakness (mononeuritis)
- distal weakness (polyneuropathy)
Signs
- focal or distal weakness
- atrophy in affected distribution
- fasciculations
- hyporeflexia
-slowing or low amplitude on conduction studies; denervation on EMG
Signs and symptoms of neuromuscular junction lesion?
Symptoms:
- fluctuating weakness
- diplopia
Signs:
- positive edrophonium test
- decremental response with repetitive stim on EMG
Note:
- edrophonium is a readily reversible acetylcholinesterase inhibitor
- prevents breakdown of acetylcholine + competitively inhibits enzyme acetylcholinesterase, mainly at the neuromuscular junction.
Signs and symptoms of muscle lesion?
Symptoms:
- proximal weakness
- difficulty climbing stairs and brushing hair?
- muscle aches
Signs:
- proximal weakness
- polyphasic, low-amplitude motor units on EMG
Signs and symptoms of midbrain lesion?
- impaired vertical gaze
- contralateral motor signs
- CN 3 palsy (plus contralateral abduction nystagmus suggest ipsilateral INO)
- CN 4 palsy
(hemiparesis suggests Weber syndrome; ataxia suggests Claude syndrome; tremor or chorea suggests Benedikt syndrome)
Signs and symptoms of pons lesion?
- dysarthria
- dysphagia
- ataxia
- contralateral hemiparesis or hemisensory loss
- ipsilateral facial sensory loss (CN5)
- ipsilateral gaze palsy (PPRF) or one and a half syndrome (PPRF and MLF)
- locked in syndrome (bilateral basis pontis; associated with ocular bobbing)
- horizontal nystagmus (often brachium pontis)
Signs and symptoms of pontomedullary junction lesion?
- Vertigo (CN 8)
- dysarthria
- horizontal or vertical nystagmus
- contralateral hemisensory loss and hemiparesis
Signs and symptoms of lateral medullar (Wallenberg syndrome)?
- ipsilateral horner syndrome
- ipsilateral limb ataxia
- ipsilateral face and contralateral body numbness
- gait ataxia
- vertigo, dizziness, nausea (CN 8)
- dysphagia (CN 9 - 12 palsises)
Signs and symptoms and medial medulla (rare)?
- contralateral hemiplegia
- contralateral posterior column sensory loss
- ipsilateral tongue weakness (CN 12 palsy)
Features of and causes of hemicord (brown-sequard syndrome)?
S&S:
- ipsilateral hemiparesis
- contralateral spinothalamic sensory loss
- ipsilateral dorsal column sensory loss
- sphincter dysfunction
Causes:
- penetrating trauma
- extrinsic cord compression
Features of and causes of anterior cord?
S&S:
- upper and lower motor paralysis
- spinothalamic sensory loss
- sphincter dysfuntion
- sparing of posterior columns
Causes:
- anterior spinal artery infarction (often involves T4-T8)
Features of and causes of central cord?
S&S:
- paraparesis
- lower motor paralysis; wasting and fasciculations in arms
- sensory loss in ‘shawl’ distribution (if in cervical region)
Features of and causes of posterior cord?
S&S
- proprioceptive and vibratory sensory loss
- segmental tingling and numbness
- sensation of constricting “bands”
Causes:
- vitamin B12 deficiency
- demyelinations (multiple sclerosis)
- extrinsic compression
Features of and causes of foramen magnum?
S&S:
- spastic quadriparesis
- neck pain and stiffness
- C2-C4 and upper facial numbness
- ipsilateral horner syndrome
- ipsilateral tongue and trapezius muscle weakness
causes:
- tumor (meningioma, chordoma)
- atlantoaxial subluxation
Features of and causes of conus medullaris?
S&S:
- lower sacral saddle sensory loss (S2-S5)
- sphincter dysfunction; impotence
- aching back or rectal pain
- L5 and S1 motor deficits (ankle and foot weakness)
Causes:
- intrinsic tumor
- extrinsic cord compression
Features of and causes of cauda equina?
S&S:
- sphincter dysfunction
- paraparesis with weakness in the distribution of multiple roots
- sensory loss in multiple bilateral dermatomes
causes:
- extrinsic tumor
- carcinomatous meningitis
- arachnoiditis
- spinal stenosis
