Diseases And Disorders

Question 1

Syringomyelia

Answer 1

• a fluid filled cyst in the spinal cord (central canal)
• from lifting heavy objects or automobile accidents
• loss of pain and temperature on both sides of the body at the sight of the cyst since this is the crossing point of the STT
• continual expansion can cause brainstem trouble if not drained

Question 2

Treponema pallidum

Answer 2

• syphilis
• spirochete will slowly invade myelinated neurons and most likely travel to the posterior columns causing demyelination of the neurons (neurosyphilis)
• loss of touch and proprioception known as tabes dorsalis (syphilitic myelopathy) —-> blindness, paralysis and dementia

Question 3

Arthrogryposis, Gordon’s Syndrome

Answer 3

• PIEZO2, a molecular ion channel that responds to stretch and proprioception, critical for mechotransduction
• genetic variant leads to congenital joint contracture in two or more areas of the body, mechanosensory deficiencies

Question 4

Acute Inflammatory Demyelinating Polyradiculopathy

Answer 4

• autoimmune disorder in which the immune system attacks the peripheral nerves, often damaging the Schwann cells
• weakness, pain, autonomic dysfunction, including respiratory failure
• recovery possible
• Guillaume Barre Syndrome
• Chronic IDP (CIDP) is similar, but waxes and wanes more, chronic immune attack on the peripheral myelin
• treatment involves plasmapheresis to help remove antibodies, administration of immunoglobulins to neutralise harmful antibodies
• corticosteroids or immunosuppressants can be used but less effective, especially in GBS

Question 5

Charcot Marie Tooth

Answer 5

• hereditary demyelinating peripheral neuropathy that affects both motor and sensory neurons due to the defect in a number of proteins/lipids and the lack of proper myelin
• PT and moderate activity

Question 6

Krabbe Disease

Answer 6

• hereditary lysosomal storage disease (deficient in galactocerebrosidase) in which there is a dysfunctional metabolism of sphingolipids resulting in the destruction of proper myelin that can occur in the PNS and CNS
• diagnosed 3-6 months after birth and results in death but can also occur later in life as a more mild form
• no known cure
• bone marrow transplant can be an optional therapy

Question 7

Metachromatic leukodystrophy

Answer 7

• hereditary lysosomal storage disease that affects both PNS and CNS
• accumulation of sulfatides that destroy myelin (deficient in the enzyme arylsulfatase-A)
• no known cure
• bone marrow transplant can be an optional therapy

Question 8

Brown Sequard Syndrome

Answer 8

• loss of touch/proprioception on one side of the body and loss of pain/temperature from the other side of the brain due to damage to one side of the spinal cord - the signals can’t get to the brain
• often a loss of muscle activity and increased deep tendon reflexes on the side of the damage, Babinski sign

Question 9

Depression

Answer 9

• linked to low levels of serotonin, norepinephrine
• selective serotonin reuptake inhibitors (SSRIs -sertraline, fluoxetine, paroxetine)
• monoamine oxidase inhibitors (MAOis - phenyelzine), tricyclic antidepressants (TCAs - imipramine, amitriptyline), serotonin and NE reuptakeinhibitors (SNRIs - venlafaxine, duloxetine)

Question 10

ADHD

Answer 10

• linked to low levels of NE

* methylphenidate, dextroamphetamine, amphetamine, atomoxetine

Question 11

PTSD

Answer 11

• linked to high levels of NE

* beta receptor antagonist (propranolol) and alpha2 receptor agonist (clonidine)

Question 12

Schizophrenia

Answer 12

• linked to unbalanced levels of dopamine

* drugs that block dopamine (haloperidol, risperidone)

Question 13

Parkinson’s

Answer 13

•linked to low levels of dopamine

Question 14

Huntington’s

Answer 14

•hereditary genetic disorder dealt with by inhibiting dopamine

Question 15

Cluster headaches

Answer 15

• unilateral
• men > women
• periorbital presentation of lacrimation and rhinorrhea at times
• repetitive, 15 min- 3hours and can have bouts that last for weeks to months
• often occur at night when sleeping
• triptans, prophylaxis Ca++ channel antagonists [verapamil], Fremanezumab

Question 16

Tension headaches

Answer 16

• bilateral
• steady, mid to moderate pain that typically lasts 30 min to 6 hrs
• due to muscle contractions in the neck and head region or may be due to other causes
• OTC pain relievers first, prescription meds include higher doses of naproxen; indomethacin, ketorolac, triptans (if patient has tension headaches + migraines)

Question 17

Migraines

Answer 17

• unilateral and pulsating
• nausea/vomiting, photophobia, photophobia, auras (visual or olfactory or auditory)
• 4-72 hrs
• higher doses of naproxen; indomethacin, ketorolac, triptans
• prophylaxis include beta blockers - propranolol, timolol) and Ca++ channel antagonists - verapamil; topiramate, valproate
• Erenumab - inhibit CGRP receptors

Question 18

Medications used for pain (some not on Exam 1 list)

Answer 18

•opioids:
-hydromorphone (mu agonist, 8-10 x more potent than morphine)
-meperidine (mu agonist, neurotoxic at high doses)
-pentazocine (k and mu agonist, lower abuse potential)
•NSAIDs
-diclofenac 9reversibel COX inhibition)
-sulindac (reversible COX inhibition)
•glucocorticoid steroids
-methylprednisolone (oral)
-prednisolone (oral)
-budesonide (oral and inhaled)
-triamcimilone (inhaled and topical)
-mometasone (inhaled and topical)
-betamethasone (topical)
•gabapentinoids:
-gabapentin and pregabalin (inhibition of VGCC by binding to the alpha 2 delta protein that delivers VGCC to the membrane surface of the presynaptic cell, decrease their trafficking to the membrane) side effects include somnolence and memory problems
•NE and/ or dual reuptake inhibitors:
-duloxetine and amitriptyline (block reuptake of NE and/or serotonin, work via and increase in descending inhibition, increasing the NE and 5HT to the dorsal horn of the SC)
-Tramadol has a similar mechanism as well as weak mu opioid agonist activity
•VGSC blockers:
-lidocaine
•triptans:
-sumatripan, naratriptan, zolmitriptan, eletriptan, rizatriptan (agonists at the serotonin receptors 5-HT 1b/d, receptors found on blood vessels and on neurons —> vasoconstriction and decrease in peripheral neuronal activity)
•beta blockers:
-propranolol and timolol (block the beta-adrenergic receptors, reducing the ability of endogenous NE and epinephrine to act the the beta receptors resulting in a decrease in hypertension and widespread decrease in sympathetic activity, full mechanism as migraine prophylactic unknown
•CGRP inhibitors:
-erenumab (fully human monoclonal antibody of calcitonin gene related peptide receptor used to prevent migraines, targets CGRP receptor)
-fremanzumab (humanised monoclonal antibody directed against CGRP that is used for chronic cluster headaches

Question 19

Dementia

Answer 19

• decreased levels of acetylcholine

* aceylcholinesterase inhibitors (done-evil, rivastigmine)

Question 20

Multiple sclerosis

Answer 20

• demyelinating disease
• loss of myelin in CNS, irreversible
• between activebouts of the disease, the population of Na+ and K+ channels in demyelinated intermodal regions can increase to levels that can support propagation of regenerative APs (though slower)
• temperature - Na+ channels open and close more quickly in response to depolarizationas temperature rises - duration of AP is reduced

Question 21

Myasthenia gravis

Answer 21

• weakness and rapid fatigue of muscles under voluntary control
• immune system produces antibodies to acetylcholine receptors or tyrosine kinase receptors at NMJ, thymus triggers or maintains production of antibodies