Neurology 2 Flashcards
What does finger flexion test?
C8, median
What does finger extension test?
C7 (radial - posterior interosseus)
What does finger abduction test?
T1 (ulnar)
What does thumb abduction test?
T1 (median)
What does wrist extension?
Extensor carpi radialis longus (c5/6, radial nerve)
Extensor carpi ulnaris (C7/8, posterior interosseus branch of the radial nerve)
What causes weakness of brachioradialis, wrist extension and finger extension? Normal triceps, reduced or absent brachioradialis reflex
Radial nerve lesion, likely spiral groove
What causes weakness of finger extension with radial deviation of the wrist on attempted extension (signifying weak extensor carpi ulnaris)? No sensory loss and reflexes are normal.
Posterior interosseus nerve lesion
Weakness of triceps and finger extensors and flexors, radial deviation of wrist and reduced or absent triceps reflex.
C7/8 root or plexus lesion
What are the causes of peripheral nerve disease according to disease onset?
Acute: GBS, porphyria, vasculitis, infectious (Lyme), toxic/drug
Subacute: toxic, nutritional, malignancy, paraneoplastic
Chronic: inherited
What is the differential diagnosis for multiple mononeuropathies?
Diabetes, vasculitis, leprosy, sarcoidosis, demyelinating neuropathies, hereditary neuropathy with liability to pressure palsies, neurofibromatosis, entrapment/compressive neuropathies
What are the clinical features of hereditary neuropathies?
Onset 1-2nd decade Insidious onset Slowly progressive distal muscle weakness and atrophy Foot drop, Pes cavus Impaired sensation Deep tendon reflexes lost
What are the causes of a purely sensory neuropathy?
Diabetes, B12 deficiency, HIV, amyloidosis, sjogrens syndrome, paraneoplastic, pyridoxine intoxication
