Neurology Flashcards
1
Q
What are the effects of B12 deficiency?
A
Subacute combined degeneration of the:
- dorsal columns
- lateral corticospinal tracts
- spinocerebellar tracts.
2
Q
Damage to the dorsal column causes?
A
Sensory Ataxia
- Loss of position and vibration sensation
- Patient will have a positive rhomberg
3
Q
Damage to the lateral corticospinal tract causes?
A
Spastic paresis
4
Q
Damage to the Spinocerebellar tract causes?
A
Contributes to ataxia
5
Q
What is atrophic glossitis?
A
Smooth shiny, erythematous tongue
6
Q
Which two diseases cause destruction of the lower motor neurons in the anterior horn and what is the result?
A
- Poliomyelitis
- Werdnig-Hoffman
- Flaccid paralysis, muscle atrophy and fasciculations
7
Q
Migraine Headaches
- Localization
- Duration
- Description
- Treatment
A
- Unilateral
- Last 4-72 hours
- Pulsating pain with nausea, photophobia or phonophobia. May have aura. Due to irritation of CN V, meninges, blood vessels (release of substance P, calcitonin gene related peptide, vasoactive peptides)
- Treatment
1. Acute: NSAIDs, triptans or dihydroergotamine
2. Prophylaxis: Lifestyle (sleep, excercise, diet), beta-blockers, calcium channel blockers, amitriptyline, topiramate or valproate
POUND
Pulsatile
One day
Unilateral
Nausea
Debilitating
8
Q
Pathophysiology of migraine headaches
A
- Pain is due to trigeminal afferents that innervate the meninges
- Release of vasoactive neuropeptides, substance P and calcitonin gene related peptide results in inflammation due to vasodilation and plasma protein extravasation
- Neuronal sensitization also occurs causing central nociceptive pathways to become more sensitive to painful and non painful stimulation.
9
Q
What medication is used to abort migraines?
A
Triptans
10
Q
What is the mechanism of action of triptans?
A
Serotonin 5-HT1b/5-HT1d agonists
- Directly counter by inhibiting release of vasoactive peptides, prompting vasoconstriction and blocking pain pathways in the brainstem
11
Q
Side effects of triptans?
A
- Significant elevations in blood pressure and cardiac events
- Avoid in those with cardiac or cerebrovascular disease
12
Q
What medications are used for migraine prophylaxis?
A
- Beta blockers
- Calcium channel blockers
- Antidepressants
- Amitrptaline and Venlafaxine - Anticonvulsants
- Valproate and Topiramate
13
Q
Where does cranial nerve VII exit the skull?
A
Via the stylomastoid foramen
14
Q
What are the 5 branches of the facial nerve?
A
- Temporal
- Zygomatic
- Buccal
- Mandibular
- Cervical
15
Q
What are the complication of a parotid gland tumor?
A
- Compress and disrupt the ipsilateral facial nerve and its branches
- Causes facial droop
16
Q
In the setting of a UTI, what is pathognomonic for pyelonephritis?
A
- WBC casts
- Formed by Tamm-Horsfall protein secreted by tubular epithelial cells
17
Q
Where else can you find WBC casts?
A
- With interstitial nephritis but urinary symptoms are usually not present.
18
Q
What is axonal reaction?
A
- The changes observed in the body of a neuron after the axon has been severed.
- Becomes visible 24-48 hours after injury.
- There is increased protein synthesis facilitating axon repair.
- Cytoplasms has enlarged round cells, with peripherally located nuclei and dispersed finely granular Nissl substance
19
Q
What is miosis and what causes it?
A
- Pinpoint pupils
- Caused by pupillary sphincter muscle contraction
- Caused when light reaches the retina, the pupillary light reflex
- Also caused when the eye is accommodating to a near object
- Innervated by parasympathetic ciliary nerves that synapse in the ciliary ganglion
- Atropine like eye drops results in blockage of this mechanism leading to mydriasis
20
Q
Causes of miosis?
A
Clonidine Barbiturates Opiates Cholinergic's Pontine stroke
21
Q
What is mydriasis and what causes it?
A
- Dilation of the pupils
- Caused by dilator papillae muscle contraction
- Under sympathetic control from fibers that synapse in the superior cervical ganglion.
- The nerve fibers follow the internal carotid artery and the ophthalmic arteries to reach the eye
- Damage anywhere along the tract results in Horner syndrome (pinpoint pupil with slight drooping of eyelid)
22
Q
Which class of medications cause dry skin?
A
- Anticholinergics
23
Q
Which class of medications cause wet skin?
A
- Cholinergics
- Sympathomimetics
24
Q
Gabapentin
- MOA
- Uses
- Side effects
A
MOA: Inhibits presynaptic high voltage gated calcium channels. Prevents influx of calcium which prevents fusion and release of neurotransmitter vesicles into the synaptic cleft; also a GABA analogue
Uses: partial (focal) seizures, peripheral neuropathy and postherpetic neuralgia
Side effects: Sedation and ataxia
25
Levetiracetam
- MOA
- Uses
- Side effects
MOA: Reacts downstream by disrupting vesicle fusion of GABA and glutamate release
Uses: Partial (focal) and Tonic-clonic seizures
Side effects: Fatigue, drowsiness, headache, neuropsychiatric symptoms such as personality change
26
Topiramate
- MOA
- Uses
- Side effects
MOA: Blocks sodium channels and increases GABA action
Uses: Partial (focal) seizures and tonic-clonic seizures; also used for migraine prevention
Side effects
27
Lamotrigine
- MOA
- Uses
- Side effects
MOA: Blocks voltage gated Na+ channels, inhibiting release of glutamate
Uses: Partial (focal), tonic-clonic and absence seizures
Side effects: Stevens-johnson syndrome (must titrate medication slowly)
28
Valproic acid
- MOA
- Uses
- Side effects
MOA: Increases Na+ channel inactivation, increases GABA concentration by inhibiting GABA transaminase
Uses: Partial (focal), tonic-clonic (first line), absence and myoclonic seizures; also used for bipolar disorder and migraine prophylaxis.
Side effects: GI distress, rare but fatal hepatotoxicity (LFTs), pancreatitis, tremor, weight gain and contraindicated in pregnancy due to neural tube defects
29
Carbamazepine
- MOA
- Uses
- Side effects
MOA: Blocks Na+ channels
Uses: First line for partial (focal) seizures and trigeminal neuralgia; also for tonic-clonic seizures
Side effects: Diplopia, ataxia, blood dyscrasias (agranulocytosis, aplastic anemia), liver toxicity, teratogenesis, induction of cytochrome p-450, SIADH and Stevens-Johnson Syndrome
30
Phenytoin
- MOA
- Uses
- Side effects
MOA: Blocks Na+ sodium channels; has zero order kinetics; disrupts the generation and propagation of action potentials in the axon hillock and proper
Uses: First line prophylaxis for Status epilepticus, first line for tonic-clonic seizures and may be used for partial (focal) seizures.
Side effects: The most of all.
- Neurologic: Nystagmus, diplopia, ataxia, sedation, peripheral neuropathy.
- Dermatologic: hirsutism, Stevens-Johnson syndrome, gingival hyperplasia, DRESS syndrome
- Musculoskeletal: osteopenia, SLE-like syndrome
-Hematologic: Megaloblastic anemia
- Reproductive: Teratogenesis (fetal hydantoin syndrome)
- Other: cytochrome P-450 induction
31
Barbiturates
- Phenobarbital, pentobarbital, thiopental, secobarbital
- MOA
- Uses
- Side effects
MOA: Facilitate GABA action by increased duration of Cl channel opening, decreasing neuron firing; contraindicated in porphyria
Uses: Sedatives for anxiety, seizures, insomnia and induction of anesthesia (thiopental)
Side effects: Respiratory and cardiovascular depression (can be fatal); CNS depression (can be exacerbated by alcohol use); dependence, drug interaction (induces cytochrome P-450
Overdose: Treatment is supportive by assisting respiration and maintaining BP
32
Phenobarbital
- MOA
- Uses
- Side effects
MOA: Increases GABA action
Uses: For partial and tonic-clonic seizures, first line in neonates
Side effects: Sedatiom, tolerance, dependence, induction of cytochrome P-450, cardiorespiratory depression
33
Benzodiazepines
- MOA
- Uses
- Side effects
MOA: Facilitate GABA action by increased frequency of Cl channel opening. Decrease REM sleep
Use: Anxiety, spasticity, status epilepticus, eclampsia, detoxification (alcohol withdrawal), night terrors, sleep walking, general anesthetic (amnesia, muscle relaxation), hypnotic (insomnia)
Side effects: Dependence, additive CNS depression effects with alcohol, less risk of respiratory depression and coma than with barbiturates
Overdose: Treatment is with flumazenil (competitive antagonist of GABA benzodiazepine receptor)
Withdrawal: can precipitate seizures with acute benzodiazepine withdrawal
34
Benzodiazepines are used for which sezures?
- MOA
- Side effects
First line for acute status epilepticus, can also be used for eclampsia seizures (MgSO4 is first line)
MOA: Increase GABA action
Side effects: Sedation, tolerance, dependence, respiratory depression
35
Ethosuximide
- MOA
- Uses
- Side effects
MOA: Blocks thalamine T-type Ca2+ channels
Uses: Absence seizures
Side effects: EFGHIJ, Ethosuximide casues fatigue, GI distress, Headaches, Itching and Stevens-Johnson syndrome
36
Vigabatrin
- MOA
- Uses
- Side effects
MOA: Increases GABA irreversibly inhibiting GABA transaminase
Uses: Partila (focal) seizures
Side effects: Black box warning for permanent vision loss
37
What are the nonbenzodiazepine hypnotics?
Zolpidem, Zaleplon and Eszopiclone
| MOA: Act via BZ1 subtype of GABA receptor
38
Phrenic nerve
Origin?
Motor and Sensory Function?
- C3, C4 and C5
- Motor function is that it innervates the diaphragm
- Sensory function is that it innervates the central part of the diaphragm, the pericardium and the mediastinal part of the parietal pleura
39
What is the interscalene nerve block?
- Regional anesthetic technique used for procedures involving the shoulder and upper arm
- Anesthetic is administered in the scalene triangle and affects the brachial plexus roots and trunks
- May also cause ipsilateral diaphragmatic paralysis by anesthetizing the roots of the phrenic nerve (C3-5) as they pass through the interscalene sheath
- Avoid in patients with chronic lung disease or contralateral phrenic nerve dysfunction
40
What is asterixis?
The rhythmic flapping of dorsiflexed hands, a manifestation of hepatic encephalopathy.
41
Hepatic Encephalopathy
- Neurologic complication of cirrhosis
- Liver can not metabolize ammonia (NH3) into urea ((NH2)2CO)
- Excess ammonia crosses BBB and leads to altered mental status
- Can lead to disorientation/asterixis, difficult arousal or coma
-Triggers:
1. Increased NH3 production/absorption (dietary protein, GI bleed, constipation, infection)
2. Decreased NH3 removal (renal failure, diuretics, bypassed hepatic flow post-Transjugular Intrahepatic Portosystemic Shunt)
Treatment
A. Lactulose (Increases NH4+ generation)
B. Rifaximin or Neomycin (Decrease NH3 producing gut bacteria)
42
What is the function of the vermis in the cerebellum?
| What can results from lesions to this region?
Vermis
- Modulates axial and truncal posture and coordination via connections with the medial descending motor systems (anterior corticospinal, reticulospinal, vestibulospinal and tectospinal tracts)
- Lesion results in truncal ataxia (wide based or unsteady gait), vertigo and nystagmus due to disruption of the inferior vermis and the flocculonodular lobe (vestibulocerebelum)
43
What is the function of the cerebellar hemispheres in the cerebellum?
What can result from lesions to this region?
- Primarily responsible for motor planning and coordination of the ipsilateral extremities via connections with the lateral descending motor systems (lateral corticospinal tract, rubrospinal tract)
- Lesions result in ipsilateral dysdiadochokinesia (impaired rapid alternating movements) limb dysmetria (overshoot/undershoot during targeted movement) and intention tremor (tremor during targeted movement)
44
What is Horner Syndrome?
Ptosis, Miosis and Anhydrosis
| -Due to lesions affecting the ipsilateral hypothalamus or sympathethic tracts in the brainstem (lateral medulla)
45
What are the signs of occulomotor nerve palsy and when does it result?
Mydriasis, complete ptosis and down and out eye deviation
- May occur with nerve compression in posterior communicating artery aneurysm or uncal herniation.
- ay occur due to microvascular nerve ischemia due to DM
- Can also result from ipsilateral lesion at the level of the anterior midbrain or midbrain tegmentum
46
What lesions can cause contralateral homonymous hemianopia?
Any unilateral visual pathway lesion beyond the optic chiasm (optic tract, lateral geniculate body, optic radiations, primary visual cortex)
47
What causes simian hand?
- Lesion to ulnar and median nerve
48
What causes wrist drop?
- Lesion to radial nerve
49
What causes ulnar claw?
- If present when trying to extend the fingers or at rest, then it is due to distal ulnar nerve lesion
- If present when trying to make a fist, then may be preachers hand which is proximal median nerve lesion
50
What causes preachers/pope's blessing hand?
- If present when trying to make a fist, then it is due to proximal median nerve lesion
- If present when trying to extend fingers or at rest then may be ulnar claw
51
Radial Nerve
Largest branch of the brachial plexus (C5-T1)
- Innervates all extensor muscles of upper limb below the shoulder
- Provides sensory innervation to the skin of the posterior arm
- Nerve travels through the radial groove on the humurus
- Vulnerable to traumatic injury at the humeral midshaft
52
What causes median claw?
- If present at rest or when trying to extend fingers, then distal median nerve
- If present when trying to make a fist, then proximal ulnar nerve lesion
53
Median claw is present when at rest or trying to extend the fingers, where is the lesion?
Distal median nerve lesion
54
Median claw is present when trying to make a fist, where is the lesion?
Proximal ulnar nerve lesion
55
Ulnar claw present when at rest or trying to extend the fingers, where is the lesion?
Distal ulnar nerve lesion
56
Ulnar claw present when trying to make a fist, where is the lesion?
Proximal median nerve lesion
57
Erb palsy is a lesion to?
| What causes it?
- Upper (Erb-er) trunk, C5-C6 roots
- Infants, lateral traction on the neck during delivery
- Adults, trauma
58
What is the muscle and functional deficit in Erb's palsy?
1. Deltoid and supraspinatus
- Deficit in abduction of the arm (hangs by the side)
2. Infraspinatus
- Deficit in lateral rotation (arm is rotated medially)
3. Biceps brachii
- Deficit in flexion and supination (arm extended and pronated)
59
Klumpke palsy is a lesion to?
| What causes it?
- Lesion to lower trunk, C8-T1 root
- Infants, upward force on arm during delivery
- Adults, trauma such as grabbing tree branch to break a fall
60
What are the muscle and functional deficits in Klumpke's palsy?
- Deficit in intrinsic hand muscles (lumbricals, interossei, thenar and hypothenar)
- Causes total claw hand because lumbricals normally flex the MCP joints and extend the DIP and PIP joints
61
Thoracic outlet syndrome is a lesion to?
| What causes it?
- Compression of the lower trunk and subclavian vessels
| - Due to cervical rib (extra rib at C7) or pancoast tumor (apex of lung tumor, most are non-small cell)
62
What are the muscle and functional deficits in thoracic outlet syndrome?
- Same as Klumpke palsy, deficit in intrinsic hand muscles (lumbricals, interossei, thenar, hypothenar)
- Causes atrophy of intrinsic hand muscles
- Leads to ischemia, pain and edema due to vascular compresion
63
Winged scapula is lesion to?
| It is caused by?
- Lesion of the long thoracic nerve (from T1 root)
| - Axillary node dissection after mastectomy, stab wounds
64
What are the muscle and functional deficits in winged scapula?
- Serratus anterior deficit
- Inability to anchor scapula to thoracic cage
- Can not abduct the arm above the horizontal position
65
What are partial focal seizures?
| What are the two types?
- Affect single area of the brain
- Originate in the medial temporal lobe
- Preceded by seizure aura, can become generalized seizure
1. Simple partial
2. Complex partial
66
Simple partial seizures
- Consciousness is intact, no loss or posticatal state
- Motor, sensory, autonomic or psychic symptoms
- Treated with narrow spectrum anticonvulsants
1. Carbamazepine
2. Gabapentin
3. Phenobarbital
4. Phenytoin
67
Complex partial seizures
- Impaired consciousness and postictal state
- May have automatisms such as lip smacking
- Treat with narrow spectrum antibiotics
1. Carbamazepine
2. Gabapentin
3. Phenobarbital
4. Phenytoin
68
What are generalized seizures and what are the five types?
```
They are diffuse (spread) types of seizures
1. Absence
2. Myoclonic
3. Tonic-clonic
4. Tonic
5 Atonic
```
69
Absence seizures
- AKA Petit mal
- 3 Hz spike and wave discharges
- No postictal (after seizure) confusion
- Blank stare
Treatment
- Ethosuximide (first line)
- MAO: blocks thalamic T-type Ca2+ channels
70
Myoclonic seizures
- Quick repetitive jerks
71
Tonic-clonic seizures
- AKA Grand mal seizure
- Alternating stiffening and movement
Treatment:
- Phenytoin, fosphenytoin (first line)
- Valproic acid (first line)
- May also use phenobarbital, carbamazepine, topiramate, lamotrigine, levetiracitam
72
Tonic seizures
- Stiffening
73
Atonic seizures
- Drop seizures, pt falls to floor
| - Commonly mistaken for fainting
74
What is epilepsy?
- Disorder of recurrent seizures
| - Does not include febrile seizures
75
What is status epilepticus?
- Continous ( > 5-30 min) or recurring seizures that may result in brain injury
76
Where is the amyloid prescursor protein located?
What does it encode?
What can its innapropriate processing lead to?
What pathways is it processed via?
Which pathway leads to disease?
- Located on chromosome 21
- Encodes highly conserved transmembrane protein
- Innapropriate processing leads to Alzheimers
- APP is processed via alpha and gamma secretase pathways or the beta and gamma secretase pathways
- The beta and gammma secretase pathway leads to production of beta amyloid
- If beta amyloid is not sufficiently cleared by cellular processes, it forms insoluble fibrils that lead to amyloid plaques
- These amyloid plaques are neurotoxic and lead to AD
- Patients who have abnormal APP processing, impaired beta-amyloid clearance or production of higher levels of APP can develop AD
77
Cluster headaches
- Localization
- Duration
- Description
- Treatment
- Unilateral
- Last 15 min - 3 hrs; are repetitive
- Repetitive brief headaches. Excrutiating periorbital pain with lacrimation and rhinorrhea. May present with horner syndrome (Ptosis, Anhydrosis, Miosis)
- Treatment:
1. Acute: Sumatriptan, 100% O2
2. Prophylaxis: Verapamil
78
Tension Headaches
- Localization
- Duration
- Description
- Treatment
- Bilateral
- Last > 30 minutes (typically 4-6 hrs); constant
- Steady pain. No Photophobia or phonophobia. No aura
- Treatment: Analgesics, NSAIDs, acetaminophen or amitriptyline for chronic pain
79
Trigeminal Neuralgia
- Repetitive, unilateral, shooting pain in the distribution of CN V
- Typically lasts <1 minute
- First line therapy is carbamazepine (blocks Na+ channels)
80
Which nerve is more likely to be damaged during excisional biopsy of enlarged lymph nodes in the posterior triangle of the neck?
What does it result in?
- The spinal accessory nerve (CN XI)
- Results in trapezius weakness with shoulder droop, impaired abduction of the arm above the horizontal plane and winging of the scapula.
- If the proximal nerve is damaged, weakness of the sternocleidomastoid may be seen
81
What nerve innervates the deltoid?
| What does injury to nerve cause?
- Axillary nerve (C5-C6)
| - Causes inability to abduct arm below the horizontal plane
82
What nerve innervates the latissimus dorsi?
| What is its action?
- Thoracodorsal nerve
| - The most powerful adductor of the arm, assists with extension and medial rotation
83
What nerve innervates the levator scapulae?
| What is its action?
- C3 and C4 cervical nerves and the dorsal scapular nerve (C5).
- Elevates the scapula and raises the medial border to allow inferior rotation of the glenoid
84
What nerve innervates the rhomboid major?
| What is its action?
- Dorsal scapular nerve (C5)
| - Inserts on the medial border of the scapula and draws it upward and medially
85
What nerve innervates serratus anterior?
What is its action?
What does injury to nerve result in?
- Long thoracic nerve
- Originates in first 8 ribs and inserts into medial border of scapula
- It rotates the scapula upward, allows abduction of the arm over the head
- Paralysis results in impaired arm abduction past the horizontal plane and winging of the scapula with no shoulder droop.
86
If a patient is homozygous for apolipoprotein E-4 allele, what are they most likely to develop in the future?
Late onset Alzheimer's disease (after age 60)
| - May be involved in the formation of senile plaques
87
What mutations are thought to cause early onset Alzheimer's in 30% of patients with the disease?
1. Amyloid precursor protein gene on chromosome 21
2. Presenilin 1 gene on chromosome 14
3. Presenilin 2 gene on chromosome 1
88
What is kinesin?
- A microtubule associated ATP powered motor protein
| - Facilitates anterograde transport of neurotransmitter containing secretory vesicles down axons to synaptic terminals
89
What is the first line treatment for absence seizures?
Ethosuximide
90
What is the treatment if a patient has absence seizures that progress to tonic-clonic seizures?
Valproate, a broad spectrum anti-seizure drug
91
What is a germinoma?
Most common pineal mass
| Midline malignant tumor arising from embryonic germ cells
92
Limitation of upward gaze with downward gaze preference
Bilateral eyelid retraction
Light near dissociation
Perinaud syndrome
