NMJ disorders, sleep, mitochondrial encephalopathies Flashcards
(121 cards)
1
Q
Spinal muscular atrophy on EMG will present as _
A
Spinal muscular atrophy on EMG will present as fibrillation potentials, denervation, and increased amplitude of motor unit potentials
2
Q
Fatiguing ptosis, double vision, dysarthria, dysphagia, and general weakness after muscle use is classic for [NMJ disorder]
A
Fatiguing ptosis, double vision, dysarthria, dysphagia, and general weakness after muscle use is classic for myasthenia gravis
3
Q
Classic signs for lambert-eaton syndrome include _
A
Classic signs for lambert-eaton syndrome include slowly progressive leg weakness, constipation, dry mouth
* Sometimes see ptosis and diplopia
4
Q
Botulism involves rapid [direction] paralysis with respiratory failure, constipation, and mydriasis
A
Botulism involves rapid descending paralysis with respiratory failure, constipation, and mydriasis
* Ocular, bulbar, extremities
5
Q
Ascending paralysis with areflexia and sensory loss is suggestive of _
A
Ascending paralysis with areflexia and sensory loss is suggestive of guillain-barre
6
Q
Botulism affects the [proteins]
A
Botulism affects the SNARE proteins
* Decreases release of Ach
7
Q
Myasthenia gravis exerts its effects via [mechanism]
A
Myasthenia gravis exerts its effects via antibodies to the post-synaptic Ach receptors
8
Q
Lambert-eaton myasthenic syndrome exerts its effect via [mechanism]
A
Lambert-eaton myasthenic syndrome exerts its effect via antibodies against voltage-gated Ca2+ on presynaptic membrane
9
Q
(MG/LES) is associated with reduced Ach release
A
LES is associated with reduced Ach release
10
Q
(MG/LES) symptoms can transiently improve after brief activation
A
LES symptoms can transiently improve after brief activation
11
Q
Edrophonium and ice pack tests can be used for the diagnosis of _ (will cause improvement of symptoms)
A
Edrophonium and ice pack tests can be used for the diagnosis of myasthenia gravis (will cause improvement of symptoms)
12
Q
MG is associated with underlying [condition]
A
MG is associated with underlying thymoma
13
Q
LES is associated with underlying [condition]
A
LES is associated with underlying small cell lung carcinoma
14
Q
Three anticholinesterase drugs that cross the BBB and can be used for Alzheimer disease:
A
Three anticholinesterase drugs that cross the BBB and can be used for Alzheimer disease: Dona Riva dances at the gala
1. Donepezil
2. Rivastigmine
3. Galantamine
15
Q
_ is an anticholinesterase drug that we historically used to diagnose MG
A
Edrophoniumis an anticholinesterase drug that we historically used to diagnose MG
* Has since been replaced by anti-AchR antibody testing
16
Q
_ is a long acting anticholinesterase that is used to treat MG; though it is a bandaid treatment
A
Pyridostigmine is a long acting anticholinesterase that is used to treat MG; though it is a bandaid treatment
* Increases Ach –> improves muscle strength
* Does not cross the BBB
17
Q
MG on EMG will show _
A
MG on EMG will show amplitude decrement on repetitive nerve stimulation
18
Q
_ and _ are two antibiotic classes that should be avoided in patients with MG
A
Aminoglycosides and Fluoroquinolones are two antibiotic classes that should be avoided in patients with MG
* Magnesium and beta blockers should also be avoided
19
Q
Muscle weakness in LES tends to be in [location] > [location] and symmetric
A
Muscle weakness in LES tends to be in legs > arms and symmetric
* Will see areflexia or hyporeflexia
20
Q
Botulism in adults involves the ingestion of _ ; while in babies it is caused by ingestion of _
A
Botulism in adults involves the ingestion of pre-formed toxin ; while in babies it is caused by ingestion of spores
* Treat with immunoglobulin (infant) or anti-toxin (adult)
21
Q
Botulism affects [NT] release
A
Botulism affects Ach release
22
Q
_ waves (1-3 Hz) are seen in stage N3
A
Delta waves (1-3 Hz) are seen in stage N3
23
Q
_ waves (4-7) are seen in stage N1
A
Theta waves (4-7) are seen in stage N1
* Mild slowing, meditation
24
Q
_ waves (8-13 Hz) are normal background waves
A
Alpha waves (8-13 Hz) are normal background waves
25
_ waves (> 13 Hz) are present during conscious thought, logical thinking, benzo use
**Beta** waves (> 13 Hz) are present during conscious thought, logical thinking, benzo use
* Awake and alert
26
Stage N1 is associated with _ waves
Stage N1 is associated with **theta waves**
* This is light sleep, easy to wake
27
Stage N2 is associated with _ waves
Stage N2 is associated with **sleep spindles and K complexes**
* This is the largest percentage of sleep
* Bruxism (twooth-grinding)
28
Stage N3 is associated with _ waves
Stage N3 is associated with **delta waves**
* Most prominent in first-half of night
* This is the deepest non-REM sleep
29
Sleepwalking, night terrors, and bedwetting are all associated with [sleep stage]
Sleepwalking, night terrors, and bedwetting are all associated with **stage N3**
* Can also see confusional arousals during N3
30
Bruxism is associated with [sleep stage]
Bruxism is associated with **stage N2**
31
REM stands for _
REM stands for **rapid eye movement** sleep
32
Dreaming, nightmares, and penile/clitoral tumescence occur during [sleep stage]
Dreaming, nightmares, and penile/clitoral tumescence occur during **REM sleep**
33
REM sleep occurs approximately every 90 minutes, with increased duration [when?]
REM sleep occurs approximately every 90 minutes, with increased duration **as night progresses (longer REM towards the morning)**
34
REM sleep involves [brain waves]
REM sleep involves **beta waves**
* Memory processing occurs
* Loss of motor tone
* Increased brain O2 use
* Variable pulse/BP
* Extraocular movements (PPRF)
35
As we age, we have _ N3 and REM
As we age, we have **decreased** N3 and REM
36
_ is the region in the hypothalamus that receives retinal inputs and serves to regulate circadian rhythms based on external light cycles
**Suprachiasmatic pathway (SCN)** is the region in the hypothalamus that receives retinal inputs and serves to regulate circadian rhythms based on external light cycles
37
The _ pathway is important for pupillary light reflex and accommodation
The **pretectal pathway** is important for pupillary light reflex and accommodation
38
Tectal (superior colliculus) pathway is needed for _
Tectal (superior colliculus) pathway is needed for **reflexive head and eye movement**
39
[NT] is particularly involved in movement, learning, memory, arousal, sleep
**Ach** is particularly involved in movement, learning, memory, arousal, sleep
40
[NT] is involved in reward, pleasure, planning, cognition, movement
**Dopamine** is involved in reward, pleasure, planning, cognition, movement
41
[NT] is important for mood, appetite, arousal, sleep-wake cycles, descending pain modulation
**Serotonin** is important for mood, appetite, arousal, sleep-wake cycles, descending pain modulation
42
[NT] is implicated in attention and arousal and is made in locus coeruleus
**NE** is implicated in attention and arousal and is made in locus coeruleus
43
The nigrostriatal pathway goes from _ to _
The nigrostriatal pathway goes from **substantia nigra** to **striatum**
44
The mesolimbic system includes _ to _
The mesolimbic system includes **ventral tegmental area** to **nucleus accumbens & limbic system**
45
The mesocortical pathway extends from _ to _
The mesocortical pathway extends from **VTA** to **cortex**
46
The SCN receives direct input from the _ and releases [NT] in response
The SCN receives direct input from the **retina** and releases **NE** in response --> tells pineal gland to secrete melatonin
* *The SCN also controls the secretion of melatonin*
47
The majority of slow wave sleep occurs in the _ of night while the majority of REM sleep occurs in the _
The majority of slow wave sleep occurs in the **first part** of night while the majority of REM sleep occurs in the **second half**
48
Normal sleep begins in _ , those with narcolepsy enter sleep directly into _
Normal sleep begins in **N1**-> N2 -> N3/4 -> REM , those with narcolepsy enter sleep directly into **REM**
49
Advanced sleep phase disorder involves _
Advanced sleep phase disorder involves **early evening sleepiness and early morning awakening**
50
_ sleep-phase disorder is common in adolescents and teenagers
**Delayed sleep-phase disorder** is common in adolescents and teenagers
51
Insomnia is defined as _
Insomnia is defined as **difficulty getting to sleep or staying asleep** or having non-refreshing sleep **for at least 1 month (acute) or 3 months (chronic)**
52
Obstructive sleep apnea is produced by _ and risk factors include _
Obstructive sleep apnea is produced by **obstruction of upper airway** and risk factors include **age, obesity, alcohol, supine sleep**
53
Narcolepsy is caused by an absence or reduction of _ , brain chemicals that help sustain alertness and prevent REM sleep
Narcolepsy is caused by an absence or reduction of **orexin (hypocretin)**, brain chemicals that help sustain alertness and prevent REM sleep
54
Narcolepsy is associated with [HLA marker]
Narcolepsy is associated with **HLA-DQB1 0602**
55
Name the four main features of narcolepsy
Name the four main features of narcolepsy:
1. **Excessive sleepiness**
2. **Cataplexy**
3. **Sleep paralysis**
4. **Hypnic hallucinations**
56
Type I narcolepsy involves _ , which is a condition by which emotion causes sudden muscle weakness
**Type I** narcolepsy involves **cataplexy** , which is a condition by which emotion triggers sudden muscle weakness
57
Hypnagogic hallucinations (narcoplepsy) occur [when?]
Hypnagogic hallucinations (narcoplepsy) occur **at onset of sleep**
58
Hypnopompic hallucinations (narcolepsy) occur [when?]
Hypnopompic hallucinations (narcolepsy) occur **at end of sleep, while waking up**
59
_ is a condition involving a crawling sensation or urge to move the legs during rest
**Restless leg syndrome** is a condition involving a crawling sensation or urge to move the legs during rest
60
Check [lab value] in patients with restless leg syndrome
Check **ferritin & iron saturation** in patients with restless leg syndrome
* Often associated with iron deficiency
* Replace iron
* Or treat w gaba, pregabalin, ropinirole
61
REM sleep behavior disorder is associated with _ proteinopathies
REM sleep behavior disorder is associated with **alpha-synuclein** proteinopathies
* Lewy body dementia
* Parkinson disease
* *It involves loss of normal muscle atonia during REM --> acting out dreams*
62
Benzos are helpful for the treatment of sleepwalking and night terrors because they _
Benzos are helpful for the treatment of sleepwalking and night terrors because they **decrease N3 and REM sleep**
63
Nonbenzodiazepine hypnotic drugs include _
Nonbenzodiazepine hypnotic drugs include:
* **Zolpidem**
* **Zaleplon**
* **Eszopiclone**
*These work by BZ1 GABA receptor*
64
[Hypnotic drug] is a melatonin receptor agonist
**Ramelteon** is a melatonin receptor agonist (MT1-2 receptor)
65
Suvorexant is a hypnotic drug that induces sleep by [mechanism]
Suvorexant is a hypnotic drug that induces sleep by **antagonizing orexin receptors**
66
Benzos are drugs that facilitate GABAa action by _
Benzos are drugs that facilitate GABAa action by **increasing frequency of Cl- channel opening**
* "Frenzodiazepines"
67
The short acting benzos can be remembered with the mneumonic _
The short acting benzos can be remembered with the mneumonic **ATOM**
* **Alprazolam**
* **Triazolam**
* **Oxazepam**
* **Midazolam**
*The others have active metabolites and long half life*
68
Barbituates faciliate GABAa action by _
Barbituates faciliate GABAa action by **increasing duration of Cl- channel opening**
69
Recall the many reactions that take place in the inner membrane/matrix of the mitochondria:
Recall the many reactions that take place in the inner membrane/matrix of the mitochondria:
* **TCA cycle**
* **Acetyl-CoA production**
* **Ketogenesis**
* **Fatty acid oxidation**
*Therefor metabolites are kept away from the rest of the cell*
70
Recall that the ETC takes place in the _
Recall that the ETC takes place in the **inner membrane of mitochondria**
* Isolates metabolic processes in the cell
* This limits the exposures of toxic substances to the rest of the cell
71
Unlike the nuclear genome, the mitochondrial genome is [shape], [size], and replication is _
Unlike the nuclear genome, the mitochondrial genome is **circular**, **small**, and **replication is asynchronous to mitochondrial fission and mitosis**
* *Recall that mitochondrial DNA only comes from mom*
72
Mitochondrial DNA will have far more mutations than nuclear DNA due to _
Mitochondrial DNA will have far more mutations than nuclear DNA due to **less proofreading, faulty polymerase, exposure to ROS**
73
_ is when a variant exists on some, but not all copies of the mitochondrial genome
**Heteroplasmy** is when a variant exists on some, but not all copies of the mitochondrial genome
* As opposed to homoplasmy
* We use these terms instead of homo/heterozygous because mitochondria are not diploid
74
The fact that a certain amount of heteroplasmy may be tolerated without clinical effect is called _ ; heteroplasmy can change over time and external factors can change the threshold (especially metabolic stress)
The fact that a certain amount of heteroplasmy may be tolerated without clinical effect is called **Threshold effect**
* *Heteroplasmy can change over time and external factors can change the threshold (especially metabolic stress)*
75
Mitochondrial disorders are typically progressive, triggered by _ , and affect tissues with high energy requirement like _
Mitochondrial disorders are typically progressive, triggered by **metabolic stress** , and affect tissues with high energy requirement like **skeletal/cardiac muscle, nerves, liver, kidney, GI, endocrine glands**
76
Mitochondrial disorders may have [non-specific lab finding]
Mitochondrial disorders may have **elevated lactate/ pyruvate**
77
Leigh syndrome is also called _ ; it is characterized by developmental delay or regression, hypotonia, dysphagia, bilateral spongiform lesions in the brain
Leigh syndrome is also called **subacute necrotizing encephalomyopathy** ; it is characterized by developmental delay or regression, hypotonia, dysphagia, bilateral spongiform lesions in the brain
* It exhibits *locus heterogeneity*
78
MELAS stands for _
MELAS stands for **Myopathy, Encephalopathy, Lactic acidosis, Stroke-like episodes**
* The mechanism is unclear but usually presents in childhood with stroke-like signs (hemiplegia, hemianopsia)
* MRS can show elevated lactate
79
MERRF stands for _
MERRF stands for **Myoclonic Epilepsy with Ragged Red Fibers**
* *The ragged red fibers are abnormal mitochondrial aggregates below plasma membrane of muscle fibers*
80
The first symptom of MERRF is usually _ followed by:
The first symptom of MERRF is usually **myoclonus + cerebellar ataxia** followed by:
* Epilepsy
* Myopathy and exercise intolerance
* Hearing loss
* Dementia
* Optic atrophy
81
Consciousness requires both awareness via a normal "hard drive" _ , and arousal via a functional on switch _
Consciousness requires both awareness via a normal "hard drive" **one functioning cerebral hemisphere** , and arousal via a functional on switch **reticular activating system**
82
"Unarousable unresponsiveness" defines _
"Unarousable unresponsiveness" defines **coma**
* Could be a lesion that destroys large area of cortex or RAS in brainstem
83
Persistent vegetative state describes a patient who is _
Persistent vegetative state describes a patient who is **arousable (eyes open) but impaired responsiveness/awareness**
84
Minimally conscious state defines a patient who is _
Minimally conscious state defines a patient who is **intact arousal with minimal reponsiveness/awareness**
85
_ occurs from a lesion affecting the *ventral pons* or caudal midbrain that causes quadriplegia, bulbar palsy, and impaired horizontal gaze
**Locked-in syndrome** occurs from a lesion affecting the *ventral pons* or caudal midbrain that causes quadriplegia, bulbar palsy, and impaired horizontal gaze
* *The RAS lies dorsal so it is spared*
* *Consciousness, vertical eye movement, blinking, hearing are preserved*
86
Locked-in syndrome is commonly caused by thrombosis of the _ artery
Locked-in syndrome is commonly caused by thrombosis of the **basilar artery**
87
Oculocephalic reflex requires [2 CNs]
Oculocephalic reflex requires **CN III, VI**
* Dolls eye reflex
88
Nerve V1 is involved in _ reflex
Nerve V1 is involved in **corneal reflex**
89
Touching the eye for corneal reflex requires [CN] to sense, and [CN] for blink
Touching the eye for corneal reflex requires **CN V** to sense, and **CN VII** for blink
90
Loss of the (motor) corneal reflex suggests _ nerve palsy
Loss of the (motor) corneal reflex suggests **facial nerve** palsy
91
Loss of gag reflex may indicate lesion of [CN] or [CN]
Loss of gag reflex may indicate lesion of **glassopharyngeal** or **vagus nerve**
92
Gag reflex involves [CN] to sense and [CN] to trigger gag
Gag reflex involves **CN IX** to sense and **CN X** to trigger gag
93
In the pupillary reflex test, [CN] senses light, [CN] constricts the pupil
In the pupillary reflex test, **CN II** senses light, **CN III** constricts the pupil
94
Lacrimation requires [afferent CN] and [efferent CN]
Lacrimation requires **V1** and **VII**
95
Cold calorics involves [CNs]
Cold calorics involves **CN VIII, III, VI**
96
Jaw jerk involves [afferent CN] and [efferent CN]
Jaw jerk involves **V3 sensory** and **V3 motor**
97
[Extrapyramidal tract] is responsible for upper extremity flexor tone
**Rubrospinal tract** is responsible for upper extremity flexor tone
* Red nucleus --> spinal cord
* Recall the red nucleus is in rostral midbrain
98
[Extrapyramidal tract] is responsible for upper extremity extensor tone
**Vestibulospinal tract** is responsible for upper extremity *extensor* tone
* Vestibular nuclei --> spinal cord
99
_ posturing happens when flexors > extensors
**Decorticate** posturing happens when flexors > extensors
* *"Flex the core"*
100
_ posturing occurs when extensors > flexors
**Decerebrate** posturing occurs when extensors > flexors
101
A lesion between the red nucleus and vestibulospinal tracts would result in _ posturing
A lesion between the red nucleus and vestibulospinal tracts would result in **decerebrate** posturing
* *If you knock out the flexors, you see unopposed extension*
* Extension of both arms and legs
102
ID the red nucleus
103
The vestibulo-ocular reflex works to stablize a visual image on the retina by _
The vestibulo-ocular reflex works to stablize a visual image on the retina by **moving the eyes in the opposite direction of head movement**
104
The flocculonodular lobe sends information to the vestibular nuclei through the _ peduncle
The **flocculonodular lobe** sends information to the **vestibular nuclei** through the **inferior** peduncle
105
Cold water in the ear mimics head movements _ irrigated ear
Cold water in the ear mimics head movements **away from** irrigated ear
* Slow eye movement will go towards the water, fast eye movement away *in patient with functional vestibular system*
106
In a patient with a normal vestibular system, cold water causes _ quick phase/ nystagmus and warm water causes _ quick phase/ nystagmus
In a patient with a normal vestibular system, cold water causes **opposite** quick phase/ nystagmus and warm water causes **same** quick phase/ nystagmus
* COWS= cold, opposite; warm, same
107
Therapeutic hyperventilation causes vaso (constriction/dilation)
Therapeutic hyperventilation causes **vasoconstriction**
* Decreased PCO2 --> vasoconstriction --> lowers cerebral blood flow
108
Tight autoregulation of cerebral perfusion is primarily driven by _ levels
Tight autoregulation of cerebral perfusion is primarily driven by **PCO2** levels
109
Acute hypoxia/ energy failure of the brain --> _ --> cell necrosis & lysis
Acute hypoxia/ energy failure of the brain --> **intracellular Na+ and Ca2+ accumulation --> osmotic swelling** --> cell necrosis & lysis
* Also see release of glutamate and free radicals which are cytotoxic
110
The most vulnerable areas of the brain to hypoxia are _
The most vulnerable areas of the brain to hypoxia are **areas with high metabolic demand & high concentration of excitatory neurotransmitter receptors**
111
The very first area of brain injury during ischemia is _
The very first area of brain injury during ischemia is **pyramidal neurons of hippocampus**
112
In addition to the hippocampus, other areas of early ischemic injury are:
In addition to the hippocampus, other areas of early ischemic injury are:
* Pyramidal neurons of cortex
* Basal ganglia
* Purkinje cells of cerebellum
113
Irreversible neuronal injury begins after _ minutes of hypoxia
Irreversible neuronal injury begins after **5** minutes of hypoxia
114
The most vulnerable areas to hypoxia can be remembered by mneumonic:
The most vulnerable areas to hypoxia can be remembered by mneumonic: **vulnerable hippos need pure water**
* Hippocampus
* Neocortex
* Purkinje of cerebellum
* Watershed areas
115
In the first **12-24 hours** after ischemic event the brain will show [histological features]
In the first **12-24 hours** after ischemic event the brain will show **eosinophilic cytoplasm + pyknotic nuclei (red neurons)**
116
In the first **24-72 hours** after ischemic event the brain will show [histological features]
In the first **24-72 hours** after ischemic event the brain will show **necrosis + neutrophil infiltration**
117
In the first **3-5 days** after ischemic event the brain will show [histological features]
In the first **3-5 days** after ischemic event the brain will show **neuronophagia + macrophages** (anoxic neuron surrounded by microglial cells)
118
In the first **1-2 weeks** after ischemic event the brain will show [histological features]
In the first **1-2 weeks** after ischemic event the brain will show **reactive gliosis + vascular proliferation** (gliosis = astrocytes)
119
**> 2 weeks** after ischemic event the brain will show [histological features]
**> 2 weeks** after ischemic event the brain will show **glial scar formation**
* Glial scar is astrocytic processes, liquefactive necrosis, release of lysosomal enzymes
120
About 1 week-1 month post ischemic event, the brain will undergo some _ necrosis
About 1 week-1 month post ischemic event, the brain will undergo some **liquefactive necrosis**
121
Lesion above the red nucleus will result in _ posturing
Lesion above the red nucleus will result in **decorticate** posturing
* The rubrospinal and vestibulospinal will both be overactive
* Will see arm flexion, leg extension
