Flashcards in Neurology III Deck (46):
Neurons of the CNS are supported by?
oligodendrocytes and astrocytes
Neurons of the PNS are associated with?
Schwann cells and ganglionic satellite cells
The peripheral nervous system includes all of the cranial nerves except?
The peripheral nervous system excludes the mesh-like system of neurons of the:
gastrointestinal system (the Enteric Nervous System)
Peripheral neuropathies have four main patterns:
mononeuropathy, mononeuritis multiplex, polyneuropathy, autonomic neuropathy
mononeuritis multiplexes involve:
multiple individual nerves
most common causes of mononeuropathies are:
compression, ischemia, infection, inflammation
the mononeuritis multiplex is what type of neuropathy?
An asymmetric, non-contiguous, multifocal neuropathy
Most common causes of mononeuritis multiplexes are:
DM, vaculitis, immune-mediated disease, infection
a polyneuropathy is what type of neuropathy?
A symmetric or contiguous multifocal neuropathy, usually starting distally.
The most common causes of polyneuropathies are:
DM, metabolic/toxic disturbances, demylination (Guillain Barre), infection (herpes zoster).
Autonomic neuropathies usually co-occur with:
Presenting sxs of autonomic neuropathies include:
GI sxs, disturbances of HR/BP, erectile dysfunction, disturbances of sweat regulation
Peripheral neuropathy can be caused by:
DM, hypothyroidism, tobacco use, systemic lupus, deficiency in vitamin B1, B12, A, E or an excess of B6.
Drugs that can cause peripheral neuropathies are :
fluoroquinolones (permanent), phenytoin, vincristine, metronidazole, statins, isoniazid, nitrofurantoin, chemotherapy
Shingles, HIV, Lyme disease, hypothyroidism, and lightning strikes can all cause:
peripheral neuropathy treatments include:
tricyclic antidepressants (SNRIs), gabapentin/pregabalin/valproate, cannabinoids, opiates, TENS
carpal tunnel syndrome (CTS) is an example of:
CTS generally presents with what sxs:
intermittent numbness and parasthesias of the 1st, 2nd, 3rd, and radial half of the 4th digit of an upper extremity.
Predisposing factors for CTS include:
heavy manual work, work with vibrating tools, obesity, DM, hypothyroidism, RA, wrist fractures, acromegaly, ganglion cysts, sleep posturing, and pregnancy
Tests commonly used to diagnose CTS are:
Phalen's maneuver, Tinel's sign, hand elevation test, NCS/EMG
Tx for CTS includes:
wrist brace while sleeping, NSAIDs, Steroids (oral, phonopharesis, injected), surgical release of the transverse ligament (increased risk of trigger thumb)
Bell palsy is?
Compressive sensorimotor peripheral neuropathy of CN VII
Bell palsy sxs:
weakness to paralysis of the facial muscles, hyperacusis, and loss of taste to the anterior 2/3 of the tongue
Bell palsy exam:
Have pt raise eyebrows. If pt has experienced insidious onset of >2wks or they are able to raise eyebrows or wrinkle their forehead then MRI of the brain is indicated.
mild Bell palsy tx:
no tx needed
Bell palsy tx:
Prednisone is effective if started early. Eye lubrication. Physical therapy, massage, and exercise.
Bell palsy prognosis:
sxs usually start improving within 2 weeks of onset with a full recovery within 3-6 months.
Guillain-Barre syndrome is diagnosed by:
history and supported by NCS and CSF
Guillain-Barre history will show:
progressive, ascending weakness (distal to proximal)
Guillain-Barre PE will show:
absent DTRs and no fever
Guillain-Barre CSF study will show:
increased protein without an increase in cell count
Guillain-Barre CBC study will show:
Guillain-Barre NCS study will show:
prolonged distal latency
plasmapharesis and/or iv immunoglobulins, breathing support prn, and physical rehab
usually starts after the 4th week and 80% will recover fully within a year
Myasthenia gravis (MG) is:
Autoimmune neuromuscular disease causing intermittent/fluctuating weakness and fatiguability
Main sx of MG:
Most commonly involved muscles of fatiguability for MG:
extraocular, facial, mastication, and pharyngeal muscles
ptosis, ophthalmoplegia/nystagmus, fatiguability with upward gaze, slowed speech and counting
MG is usually caused by autoimmune ABs against the nicotinic acetylcholine receptors. MG can also be caused by ABs against muscle specific kinase
acetylcholinesterase inhibitors (neostigmine, pyridostigmine) and immunosuppressant (prednisone, cyclosporine, azothiprine)
Severe MG tx:
plasmaphoresis and IVIG