Demyelinating disorders Flashcards
Multiple Sclerosis (MS)
● MS is a relatively common neurologic condition that most likely has an autoimmune pathophysiologic basis
● Patients are most often under the age of 50 at onset of symptoms.
○ Greatest incidence in young adults (18-40)
Multiple Sclerosis (MS) pathophysiology
○ MS is the most common Demyelinating
Disease of the Central Nervous System.
Multiple Sclerosis (MS)
○ Almost certainly an autoimmune disorder.
○ As the myelin are attacked by the WBCs,
gray-white translucent areas of inflammation
develop in the white matter (called Plaques).
○ As the acute inflammation of the plaque resolves with time, the plaque
becomes a “remote plaque.”
○ Most commonly, these plaques occur in the
Periventricular White Matter (around ventricles),
and in the Optic Nerves and Spinal Cord.
○ Patients with MS typically follow either a relapsing-remitting pattern of
episodes, or a primary progressive course
Multiple Sclerosis (MS) S/S
○ Symptoms usually progressively develop over hours to days, and then
may disappear after a few days or weeks.
■ However, exam may reveal residual deficit even after symptoms have
resolved (because the plaque causes permanent damage)
○ The most common initial presentation may include motor weakness,
numbness, tingling, or unsteadiness in a limb
○ Diplopia can occur with Internuclear Ophthalmoplegia (INO)
What causes diplopia with MS?
○ This is caused by injury to the Medial Longitudinal
Fasciculus (MLF), a white matter tract that connects
different motor nuclei in the brainstem that
normally allows conjugate eye movements.
○ When the affected eye attempts to adduct (medial
gaze), it adducts minimally, if at all, or lags behind.
■ The other eye abducts as it should, but there is
often nystagmus of the eye
○ This causes the patient to “see double” (diplopia).
Multiple Sclerosis (MS) Diagnosis
○ MRI is the imaging modality of choice.
○ Lesions are often found in the periventricular
white matter, brainstem, or the spinal cord.
○ Acute lesions will enhance with contrast.
○ MRI is the imaging modality of choice.
○ Lesions are often found in the periventricular
white matter, brainstem, or the spinal cord.
○ Acute lesions will enhance with contrast.
What will CSF show with MS?
○ CSF may reveal sterile lymphocytosis (mild), or
slightly increased protein concentration
(especially soon after an acute relapse).
○ Elevated CSF IgG and discrete bands of IgG
(specifically “Oligoclonal Bands”) are
characteristic findings.
○ Diagnosis cannot be based on CSF labs alone
Multiple Sclerosis (MS) Management
○ Treatment of Acute Relapses-
■ Corticosteroids- PO or IV Methylprednisolone for 3-5 days.
○ Relapse Reduction Management-
■ For a long time IV, IM, and SC medications were the only options.
● Interferon beta 1a (Avonex), Interferon beta 1b (Betaseron), Glatiramer
(Copaxone), Natalizumab (Tysabri), some others
■ Newer PO options seem to be effective, but are quite expensive.
● Teriflunomide (Aubagio), Fingolimod (Gilenya), Dimethyl Fumarate (Tecfidera)
○ Symptomatic Therapy-
■ Pregabalin (Lyrica), Gabapentin (Neurontin), Amitriptyline (Elavil), Baclofen
or Tizanidine, SSRIs or SNRIs.
Guillain-Barre Syndrome
● An uncommon but serious acute immune-mediated peripheral
polyneuropathy (AKA Acute Idiopathic Polyneuropathy).
● Often follows minor infections, immunizations, or surgical procedures, but the cause is not identified in many cases
○ May be associated with recent Campylobacter jejuni, Mycoplasma pneumoniae, or Zika virus infection
Guillain-Barre Syndrome pathophysiology
○ Inappropriate immune response
(autoimmune) that results in the
attack of Schwann Cells
(demyelination of the PNS).
○ Interrupts motor and sensory signals
Guillain-Barre Syndrome clinical presentation
○ Characteristically presents with symmetric extremity weakness that often begins distally and ascends progressively. Weakness typically progresses over hours to a few days.
○ Deep tendon reflexes are decreased or absent.
○ Sensory abnormalities are common, but less severe than motor Sxs.
○ Cranial nerves are affected in 45-75% of patients.
○ Neuropathic pain is common (more than 85%) and can be severe.
○ Significant autonomic dysfunction can occur…
■ Tachycardia, cardiac arrhythmias, labile BP, paralytic ileus, etc.
○ Can become very life-threatening if the innervation to respiratory muscles
(25-30%) or swallowing become involved
Guillain-Barre Syndrome diagnosis
○ Diagnosis of GBS is made by recognizing the pattern of rapidly evolving motor weakness, associated loss of reflexes, absence of fever or other systemic symptoms, and the presence of possible characteristic antecedent events
○ CSF analysis after lumbar puncture-
■ Typically reveals elevated protein level without an increase in cell
count (normal WBC counts, AKA lack of pleocytosis)
○ Electrophysiologic studies (NCS/EMG)
○ When and if suspected, Pulmonary
Function Tests should be performed
to assess vital capacity
Guillain-Barre Syndrome management
○ Patients should be hospitalized quickly so that they can be monitored closely for respiratory dysfunction or autonomic dysregulation.
■ Death can occur from respiratory failure, hypotension, and/or arrhythmias
○ Consider early transfer to the ICU and prophylactic intubation if there is rapid
progression of weakness with involvement of UEs or face.
○ DVT prophylaxis is important if the patient is not ambulatory.
○ Treatments of choice- IVIG and Plasma Exchange, recommended for patients
requiring intubation or have difficulty with ambulation (most patients)
Guillain-Barre Syndrome prognosis
○ 4-15% mortality rate, occurring from complications of GBS (usually pulm).
○ Most patients with GBS begin to recover at around 28 days.
■ If complete recovery occurs, takes an average of 200 days
○ Many have residual motor and/or sensory loss at 12 months after Dx
Amyotrophic Lateral Sclerosis (ALS)
● ALS is also known as Lou Gehrig’s Disease.
● It is a progressive, fatal neurodegenerative
disease involving motor neurons
Risk factors for ALS
● Formaldehyde and smoking are risks.
● ALS is slightly more common in males.
