Exam II Flashcards
What are the three parts of a motor unit?
Peripheral axon, neuromuscular junction and innervated myocytes
What is the name of the cells that produce myelin in the PNS?
Schwann cells
A peripheral nerve injury that is characterized by direct injury to an axon and degeneration of peripheral segments and results in decreased amplitude and axon density.
Axonal neuropathy
Axonal neuropathy in which myelin loss is a secondary result is called:
Wallerian degeneration
A peripheral nerve injury that is characterized by damage to Schwann cells resulting in random internode demyelination and slow nerve conduction velocity.
Demyelinating neuropathy
Demyelinating neuropathy is also called:
Segmental demyelination
Carpal tunnel syndrome involves entrapment of a single nerve. This pattern of peripheral neuropathy is termed:
Mononeuropathy
“Stocking-and-glove” parasthesia and anasthetia involve diffuse and asymmetric neuronal loss. This pattern of peripheral neuropathy is termed:
Polyneuropathy
Damage that randomly affects portions of individual nerves follows which pattern of peripheral neuropathy?
Polyneuritis multiplex
The disorder that is characterized by acute motor neuron demyelination that results in ascending paralysis is termed:
Guillan-Barre syndrome
GBS is most common in:
Males aged 15-35 and 50-57 years
Which disorder is characterized by symmetric, segmental demyelination/remyelination and can relapse and progress to chronic GBS?
Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
What is the most common peripheral neuropathy?
Diabetic neuropathy
Which peripheral neuropathy is considered mixed due to its damage of both axons and myelin?
Diabetic neuropathy
What is the most highly recommended treatment option in diabetic neuropathy?
Daily foot inspection
Which cause of peripheral neuropathy results in altered axonal transport and cytoskeletal damage and is observed in the distal extremities?
Environmental toxins
Which cause of peripheral neuropathy results in damage to peripheral nerves and involves the polyneuritis multiplex?
Systemic vasculitis
Genetic disorders that result in peripheral neuropathy are attributed to mutations in which gene?
PMP22
The genetic disorder that leads to peripheral neuropathy most commonly in young adults and is slowly progressive is termed:
Charcot-Marie-Tooth disease
In myasthenia gravis, autoantibodies block:
Post-synaptic Ach receptors
MG is characterized by:
Thymic hyperplasia and extraocular weakness and becomes worse with e-stimulation
MG is most common in:
Females in the 3rd decade of life and males in the 5th-6th decade of life
Which test inhibits acetylcholinesterase (AchE)?
Tensilon test
In Lambert-Eaton syndrome, autoantibodies inhibit:
Pre-synaptic calcium channels
Which form of NMJ disorder mimics MG and Lambert-Eaton syndrome?
Congenital myasthenic syndrome
Which two bacteria cause infectious NMJ disorders?
C. tetani and C. botulinum
C. _____ increases Ach release, while C. _____ decreases Ach release.
tetani; botulinum
Which muscle fiber is characterized as slow twitch, aerobic, dark and uses fat metabolism?
Type I
Which muscle fiber is characterized as fast twitch, anaerobic, white and uses glycogen metabolism?
Type II
Disuse atrophy and glucocorticoid atrophy primarily involve which fibers?
Type II
The group of most common forms of muscular dystrophy are termed:
Dystrophinopathies
Duchenne muscular dystrophy is characterized by:
Absence of dystrophin
What is the most common dystrophinopathy?
DMD
Becker MD is characterized by:
Dystrophin is present but has variable function
DMD is most common in which population?
Childhood onset (Age 5), wheelchair-bound in their teens and lethal in early adulthood
BMD is most common in which population?
Delayed onset (adolescence), less severe than DMD
What are the features of DMD and BMD?
Pelvic girdle muscles primarily impacted and pseudohypertrophy of calf muscles
Lab values for patients with DMD/BMD include finding increased:
Creatine kinase
How do patients die from DMD/BMD?
Respiratory insufficiency
The type of inflammatory myopathy that is autoimmune and is most common in males aged 45-60 years.
Polymyositis
The most common inflammatory myopathy in children is termed:
Dermatomyositis
The most common myopathy among elderly patients is termed:
Inclusion body myositis
Overproduction of thyroxine, goiter or Graves disease are characteristics of:
Thyrotoxic myopathy
Binge drinking, rhabdomyolysis and a progression into renal failure are characteristics of:
Ethanol myopathy
Drug myopathy is characterized by adverse effects by various agents, the most common being:
Statins
The peripheral nerve sheath tumor that most commonly involves CN8 is called:
Schwannoma (Vestibular schwannoma)
Multiple CNS and cutaneous schwannomas absent vestibular schwannomas is termed:
Schwannomatosis
Neurofibromatosis that exhibits pronounced neurofibromas and mutations on chromosome 17 is characteristic of:
Neurofibromatosis type I
NF1 is also called:
von Recklinghausen disease
Bilateral vestibular schwannomas and the merlin gene that most commonly result in vision and hearing problems are all characteristics of:
NF2
Swelling of the soma and displacement of the Nissl substance are characteristic of:
Reversible neuronal injury
The presence of “red neurons,” eosinophilia and axonal swelling are all characteristic of:
Irreversible neuronal injury
Minimal fibrosis occurs following CNS injury to:
Astrocytes
The presence of glial filaments sprouting is termed:
Gemistocytic astrocyte
Which cells produce myelin in the CNS?
Oligodendrocytes
Which cells are considered CNS phagocytes?
Microglia
What is the function of the choroid plexus?
Produces CSF
The rabies virus produces _____ in the cytoplasm.
Negri bodies
The presence of an “owl’s eye” is indicative of:
Cytomegalovirus
The presence of Lewy bodies is indicative of:
Parkinson’s disease
Neurofibrillary tangles and beta-amyloid plaques are indicative of:
Alzheimer’s
Accumulation of lipids in the cytoplasm or lysosomes is indicative of:
Lipofuscin
Blood-brain-barrier disruption resulting in increased permeability is termed:
Vasogenic cerebral edema
Neuronal/glial membrane injury resulting in increased intracellular fluid retention is termed:
Cytotoxic cerebral edema
What are the three distinct features of cerebral edema?
Flattened gyri, narrowed sulci, and ventricular compression
Increased CSF volume most commonly involves:
Altered flow or resorption
Hydrocephalus that occurs at
Cranial enlargement
Hydrocephalus that occurs at >2 years old results in:
Increased ICP and ventricular enlargement
What is the most common treatment for hydrocephalus?
Shunting
Hydrocephalus that occurs as a result of an infarct or neurodegeneration is termed:
Hydrocephalus ex vacuo
What is the most common form of brain herniation?
Subfalcine (cingulate)
Which brain hernia involves CNIII and Duret hemorrhage?
Transtentorial (uncinate)
Duret hemorrhage involves vessels that enter the _____ that are then disrupted by herniation.
Pons
Injury to the cortex and the red nuclei that results in extension of the legs along with internal rotation is most likely:
Decorticate rigidity
Injury to the brainstem between red nuclei and vestibular nuclei that results in extension of all 4 limbs and pronation of the arms/plantar flexion is most likely:
Decerebrate rigidity
What is the most common cause of neurologic morbidity?
Cerebrovascular disease
Which features are all considered a “stroke?”
Thrombotic occlusion, embolic occlusion and vascular rupture
Decreased O2 partial pressure and decreased O2 carrying capacity are characteristics of:
Functional hypoxia
Ischemia and hypoxia are indicative of what type of necrosis?
Liquefactive
A patient that exhibits severe hypotension is likely experiencing:
Widespread ischemic/hypoxic injury
What is the most common focal cerebral ischemia?
Emboli
Primary brain parenchymal hemorrhage is most common in:
Older adults (60 or older)
What are the most common locations for primary brain parenchymal hemorrhage?
Thalamus, pons and cerebellum
A patient presents with the “worst headache I’ve ever had.” You would suspect:
Subarachnoid hemorrhage
Subarachnoid hemorrhaging most commonly involves the rupture of:
Saccular (berry) aneurysm
In arteriovenous malformations, a tangle of arteries and veins are connected via:
1 or more fistula
Arteriovenous malformations are most common in:
Males ages 10-30 years
Hypertension has what effect on vessel walls?
Weakens vessel walls
A single artery occlusion is termed a:
Lacunar stroke
Ruptured small cerebral vessels where a “slit-like cavity” remains is termed:
Slit hemorrhage
A patient presents with global cerebral dysfunction, with a diastolic BP of >130 and increased ICP. You suspect:
Acute hypertensive encephalopathy
Systemic, autoimmune vasculitis with fibrinoid necrosis of small arteries is termed:
Polyarteritis nodosa
Primary angiitis of the CNS is characterized by chronic inflammation of:
Multiple parenchymal and subarachoid vessels
CNS trauma is most common in:
Males
Silent CNS trauma is most likely associated with:
The frontal lobe
CNS trauma of the spinal cord is:
Disabling
If a patient has had fatal CNS trauma, which area was most likely damaged?
Brainstem
What tissues are damaged in CNS trauma?
Parenchyma and vasculature
How would you assess CNS trauma?
Airway, breathing, circulation and disability (ABCD)
A contusion at the impact site is called a _____, while a contusion on the opposite side of impact is called a _____.
Coup; contrecoup
Tearing of the cerebral parenchyma is considered a:
Laceration
Tissue displacement or injury and edema are characteristics of a:
Contusion
Movement of one region relative to another, commonly from angular acceleration is called:
Diffuse axonal injury (DAI)
Reversible altered consciousness from head injury in the absence of a contusion is called a:
Concussion
Epidural hemorrhaging is characterized by damage to _____, while subdural hemorrhaging is damage due to _____.
Dural artery; Rapid movement tears veins
The most common CNS malformation is:
Neural tube defects
An asymptomatic bony defect is indicative of:
Spina bifida occulta
Extension of the CNS through a vertebral defect is indicative of:
Myelomeningocele
Abnormal widening of the central canal is called:
Hydromyelia
A cyst within the cord is called:
Syringomyelia (syrinx)
Which microbe(s) is/are responsible for acute pyogenic meningitis in neonates?
E. coli and Group B strep.
Which microbe(s) is/are responsible for acute pyogenic meningitis in adolescents and young adults?
Neisseria meningitidis
Which microbe(s) is/are responsible for acute pyogenic meningitis in older adults?
Strep. pneumoniae and Listeria monocytogenes
Which form of meningitis is self-limiting?
Aseptic
Diffuse parenchymal infections are caused by _____, while localized and septic parenchymal infections are caused by _____.
Viruses; bacteria
Which types of parenchymal infections are associated with meningitis?
Viral and fungal
What is the most common disorder of myelin and what is the prevalence in the US?
Multiple sclerosis; 1 per 1000
What are the risk factors for MS?
Young adults, females and a family history of MS
What genetic antigen is well established as a predisposition for MS?
HLA-DR2
Plaques associated with MS will most likely target which cranial nerve?
CNII (Optic)
Wernicke-Korsakoff syndrome is associated with a deficiency of:
Thiamine
Which metabolic disorder mimics hypoxia, with the hippocampus most likely susceptible?
Hypoglycemia
Which metabolic disorder is associated with demyelination?
Vitamin B12 deficiency
The most common cause of dementia, characterized by beta-amyloid plaques, is called:
Alzheimer’s disease
Patients with Alzheimer’s disease will be most commonly disabled by _____ within _____.
Lethal pneumonia within 5-10 years
What age group presents the highest risk for developing Alzheimer’s? Lowest risk?
Highest: >85 years (47%)
Lowest: 65-74 years (3%)
Motor disturbances, tremor, bradykinesia and damage to dopaminergic neurons are all indicative of:
Parkinson’s disease
Parkinson’s disease will most likely attack the:
Substantia nigra
What are the two most commonly involved structures in Huntington disease?
Caudate and putamen nuclei
Huntington disease has a delayed onset, most commonly affecting ages:
30-40 years
The Huntington gene is present on which chromosome?
Chromosome 4
What functions are spared in ALS?
Sensation and extraocular motor
Upper and lower motor neurons are commonly killed in which disease?
ALS
Patients with ALS often die as a result of:
Respiratory paralysis
Most CNS tumors are:
Primary
Which gliomas are diffuse/infiltrative?
Astrocytoma and oligodendroglioma
Which glioma is not diffuse or infiltrative?
Ependymoma
What is the mean survival time for a glioblastoma?
15 months
Which glioma is the most lethal and has the poorest prognosis?
Astrocytoma
What is the most common embryonal neoplasm?
Medulloblastoma
What is the most common CNS tumor among immunosuppressed (AIDS) patients?
Primary CNS lymphoma (Diffuse large B cell lymphoma)
What is the most common benign tumor of adults?
Meningioma
What is the #1 cause of morbidity and mortality in the US?
Vascular disease
What are the 2 mechanisms of vascular disease?
Narrowing/obstruction of the lumen and Weaking of the vessel walls
What are the 3 layers of vessel walls?
Intima, media and adventitia
The inner portion of the media is supplied by:
Diffusion of blood from the lumen
The outer portion of the media is supplied by:
Vasa vasorum
What is the order of the vascular pathway?
Large elastic arteries –> Medium-sized muscular arteries –> Small arteries –> Arterioles
What are the 3 main vascular anomalies?
Intracranial berry aneurysms, arteriovenous fistulas, and fibromuscular dysplasia
What are the effects of increased blood pressure?
Stimulates atrial natriuretic peptide (ANP), reduced sodium resorption and vasodilation
What are the effects of decreased BP?
Stimulates renin-angiotensin system (RAS), increased sodium resorption and vasoconstriction
Blood pressure medications influence what 2 things?
Angiotensin II receptor blockers and diuretics
What is the clinical BP reading to be considered hypertension?
> 140/90
Percentage of HTN cases considered “essential HTN?”
95%
Which race is more at risk to HTN?
African-Americans
In what ways does the vascular wall respond to injury?
Smooth muscle cell recruitment/mitosis and irreversible intimal thickening
Which pattern of arteriosclerosis is characterized by calcium deposits in the arteries?
Monckenberg medial sclerosis
Which pattern of arteriosclerosis affects small arteries and could result in ischemic injury?
Arteriolosclerosis
The tunica media is separated from the tunica adventitia by the:
External elastic lamina
Atherosclerosis is most likely to involve:
Large elastic arteries
Which layer of the vessel wall contains endothelial cells?
Tunica intima
What percentage of the general population are hypertensive?
25%
What is a standard response following vascular injury?
Medial thickening and intimal thickening
Which of the following is not a category of arteriosclerosis?
A. Arteriolosclerosis
B. Monckenberg medial sclerosis
C. Endotheliosclerosis
D. Atherosclerosis
C. Endotheliosclerosis
Without appropriate treatment, what percentage of hypertensive individuals will die from a stroke?
1/3 or 33%
Metabolic syndrome is not associated with which of the following?
A. Dyslipidemia
B. Foam cells
C. Insulin resistance
D. Central obesity
B. Foam cells
Extravasation of blood into the wall of an artery is associated with a:
False aneurysm
Which type of aneurysm is associated with all 3 layers of a vessel or heart wall?
True aneurysm
What are 2 key features of atherosclerotic plaques?
Thickening of the tunica intima and lipid accumulation
What percent of arteriosclerosis is atherosclerosis?
99%
A polyneuropathy is most likely to have a _____ distribution.
Symmetric
The clinical features _____ involve ptosis and diplopia.
MG
Acute renal failure may result from rhabdomyolysis secondary to:
Binge-drinking
