inflammatory_neuropathies.ppt

Editor's Notes

• #3: Inflammatory neuropathies can be considered as a group of immune-mediated disorders affecting the peripheral nervous system in which hematogenous leukocytes actively participate in axonal degeneration, demyelination or both, with resultant motor and sensory deficits. Inflammatory neuropathies may be divided into three major clinicopathological subgroups: Guillain-Barre syndrome (GBS), an acute disorder affecting peripheral nerves and nerve roots with maximum severity attained within 4 weeks from disease onset; chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), a chronic disorder affecting peripheral nerves and nerve roots with maximal severity attained after 8 weeks following disease onset, and vasculitic neuropathy, an acute-subacute disorder that commonly affects multiple individual or groups of peripheral nerves sequentially [
• #4: Inflammatory neuropathies can be considered as a group of immune-mediated disorders affecting the peripheral nervous system in which hematogenous leukocytes actively participate in axonal degeneration, demyelination or both, with resultant motor and sensory deficits. Inflammatory neuropathies may be divided into three major clinicopathological subgroups: Guillain-Barre syndrome (GBS), an acute disorder affecting peripheral nerves and nerve roots with maximum severity attained within 4 weeks from disease onset; chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), a chronic disorder affecting peripheral nerves and nerve roots with maximal severity attained after 8 weeks following disease onset, and vasculitic neuropathy, an acute-subacute disorder that commonly affects multiple individual or groups of peripheral nerves sequentially [
• #5: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #6: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #7: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #8: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #9: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #10: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #11: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #12: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #15: infections with C. jejuni, cytomegalovirus, Epstein±Barr virus and Mycoplasma pneumoniae were shown to be significantly associated with GBS. In recent years Zika virus, a flaviviruswith large outbreaks in Asia, South America, and Central America, has been associated with an increased incidence of GBS. In 1976, there was a greater incidence of GBS associated with the swine flu vaccine. Additionally, there was a slightly increased risk after the 2009 H1N1 influenza vaccine. Given that influenza infection portends a higher risk of GBS than the vaccination, vaccination continues to be recommended.
• #16: antigens in the lipopolysaccharides of C. jejuni can induce the production of crossreactive antibodies against gangliosides in the myelin sheath or axolemma The variation of ganglioside antibody speci®cities may be caused by antigenic differences in the pathogen, e.g. specific serotypes of C. jejuni (Penner 4 and 19) generate GM1 antibodies, whereas other serotypes (Penner 8 and 37) can trigger immune responses to GD1a [6.]. GM1 and GD1a IgG antibodies are primarily associated with the AMAN/AMSAN forms, whereas GM2 IgM antibodies are seen after cytomegalovirus infection and are associated with a mild AIDP [6.]. GQ1b antibodies are elevated in Miller±Fisher syndrome and in GBS with ophthalmoplegia, and have also been shown to crossreact with C. jejuni [7]. The variability of GBS may thus, at least partly, be caused by the difference in the pathogen causing the preceding infection.
• #17: The CSF protein is normal, such as in our patient, in one-half in the first week and elevated in up to 88% at 2 weeks Pleocytosis (elevated white blood cell count) raises the question of a malignant or infectious process (human immunodeficiency virus, Lyme, cytomegalovirus) or sarcoidosis.
• #20: Ultrasound examination may demonstrate enlargement of nerve roots and peripheral nerves
• #21: Respiratory function must be monitored closely with frequent measurement of forced vital capacity and maximal expiratory and inspiratory pressures. Autonomic function should also be closely monitored with particular vigilance for cardiac arrhythmias, urinary retention, and constipation. The 2 first-line treatments for GBS, IVIg and plasma exchange are equally efficacious. Either should be started immediately in patients with clinically defined GBS, even in the setting of normal electrodiagnostic studies and CSF analysis. The standard dosing for IVIg is 2 g/kg divided over 2 to 5 days.
• #22: Respiratory function must be monitored closely with frequent measurement of forced vital capacity and maximal expiratory and inspiratory pressures. Autonomic function should also be closely monitored with particular vigilance for cardiac arrhythmias, urinary retention, and constipation. The 2 first-line treatments for GBS, IVIg and plasma exchange are equally efficacious. Either should be started immediately in patients with clinically defined GBS, even in the setting of normal electrodiagnostic studies and CSF analysis. The standard dosing for IVIg is 2 g/kg divided over 2 to 5 days.
• #23: Treatment-related fluctuations occur in about 10% of patients within the first 2 months. It is recommended to treat the patient with IVIg or plasma exchange, whichever treatment they responded to initially. Clinical deterioration beyond the first 2 months should raise the possibility of acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).
• #24: Treatment-related fluctuations occur in about 10% of patients within the first 2 months. It is recommended to treat the patient with IVIg or plasma exchange, whichever treatment they responded to initially. Clinical deterioration beyond the first 2 months should raise the possibility of acute-onset chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).
• #25: A 47-year-old man with a history of juvenile rheumatoid arthritis presented to the emergency department with a 1-week of blurry vision, intermittent diplopia, and gait instability. He had a sinus infection treated with antibiotics 1 week before the onset of neurologic symptoms. He denied any dysarthria, dysphagia, dyspnea, or generalized weakness. He reported patchy sensory changes that were resolving. On examination, he had complete ophthalmoplegia (Video 1), areflexia, and impaired tandem gait.
• #26: A 47-year-old man with a history of juvenile rheumatoid arthritis presented to the emergency department with a 1-week of blurry vision, intermittent diplopia, and gait instability. He had a sinus infection treated with antibiotics 1 week before the onset of neurologic symptoms. He denied any dysarthria, dysphagia, dyspnea, or generalized weakness. He reported patchy sensory changes that were resolving. On examination, he had complete ophthalmoplegia (Video 1), areflexia, and impaired tandem gait.
• #27: A 47-year-old man with a history of juvenile rheumatoid arthritis presented to the emergency department with a 1-week of blurry vision, intermittent diplopia, and gait instability. He had a sinus infection treated with antibiotics 1 week before the onset of neurologic symptoms. He denied any dysarthria, dysphagia, dyspnea, or generalized weakness. He reported patchy sensory changes that were resolving. On examination, he had complete ophthalmoplegia (Video 1), areflexia, and impaired tandem gait.
• #28: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #29: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #30: A 65-year-old librarian with a past medical history of hypertension developed conjunctivitis with ocular erythema and discharge 1 week before New Year’s eve. These symptoms resolved with antibiotic eye drops. On New Year’s eve, she developed bilateral hand clumsiness resulting in difficulty typing. Within 1 day, her gait deteriorated significantly. She was admitted to a community hospital where she developed progressive dyspnea requiring intubation. Cerebrospinalfluid (CSF) protein, glucose, leukocyte counts, Gram stain, and culture were normal. She was given 1.5 g/kg of intravenous immune globulins (IVIg) divided over 3 days for presumed Guillain-Barre´ syndrome (GBS) before transfer to a tertiary care hospital. After transfer, an MRI of the spine with and without gadolinium demonstrated nerve root enhancement and enlargement Nerve conduction studies revealed absent F responses. Although this can be an isolated finding in early GBS, it could also be explained by the sedation given in the intensive care unit and the patient’s asleep state.
• #31: a GBS variant, is characterized by the classic clinical triad of ophthalmoplegia, ataxia, and areflexia. Other cranial neuropathies, dysesthesia, and micturition problems may also occur. Miller-Fisher syndrome comprises 5%to 10% of GBS cases in Western countries and a higher proportion in Asia. It often follows C jejuni or Haemophilus influenzae infection. For description of other GBS variants please refer to (Table 1). The characteristic anti-GQ1b ganglioside antibodies react with C jejuni surface epitopes supporting molecular mimicry between nerve and bacteria. Electrodiagnostic studies may demonstrate sensory predominant axonopathy
• #32: a GBS variant, is characterized by the classic clinical triad of ophthalmoplegia, ataxia, and areflexia. Other cranial neuropathies, dysesthesia, and micturition problems may also occur. Miller-Fisher syndrome comprises 5% to 10% of GBS cases in Western countries and a higher proportion in Asia. It often follows C jejuni or Haemophilus influenzae infection. For description of other GBS variants please refer to (Table 1). The characteristic anti-GQ1b ganglioside antibodies react with C jejuni surface epitopes supporting molecular mimicry between nerve and bacteria. Electrodiagnostic studies may demonstrate sensory predominant axonopathy
• #33: The prognosis is generally good, regardless of whether IVIg or plasma exchange is given. For this reason, many experts do not treat patients with classic Miller- Fisher syndrome, although patients with progressive weakness and ophthalmoplegia (“ophthalmoplegic GBS”) should be treated.
• #34: The prognosis is generally good, regardless of whether IVIg or plasma exchange is given. For this reason, many experts do not treat patients with classic Miller- Fisher syndrome, although patients with progressive weakness and ophthalmoplegia (“ophthalmoplegic GBS”) should be treated.
• #35: CASE 3. THE 61-YEAR-OLD BANKER WITH DIABETES WITH PROGRESSIVE WEAKNESS
• #36: The progressive finger and hand weakness resulted in trouble with activities of daily living. He reported mild numbness in the feet, but no paresthesia or neuropathic pain. He denied bowel, bladder, or bulbar dysfunction. On examination the patient had symmetric weakness of his proximal and distal lower extremities (Medical Research Council grade 4/5 throughout, except dorsiflexion was a 3/5). Pinprick sensation was decreased to the level of the knees and hands. Vibratory sensation was absent to the level of the ankles and normal in the fingers. He was areflexic.
• #37: The progressive finger and hand weakness resulted in trouble with activities of daily living. He reported mild numbness in the feet, but no paresthesia or neuropathic pain. He denied bowel, bladder, or bulbar dysfunction. On examination the patient had symmetric weakness of his proximal and distal lower extremities (Medical Research Council grade 4/5 throughout, except dorsiflexion was a 3/5). Pinprick sensation was decreased to the level of the knees and hands. Vibratory sensation was absent to the level of the ankles and normal in the fingers. He was areflexic.
• #41: In multiple motor nerves, there are prolonged distal latencies, slowed conduction velocities, and conduction block Abnormalities are bolded
• #42: and partial motor conduction block as represented in the left median–abductor pollicis brevis compound muscle action potential waveforms
• #44: CIDP is the most common, chronic autoimmune polyneuropathy. The estimated incidence is 0.33 per 100,000 and prevalence 2.81 per 100,000.21 Both cellular and humoral mechanisms are involved
• #45: One-half of patients have typical CIDP, which is characterized by symmetric, proximal, and distal generalized weakness; distal large fiber sensory impairment; and areflexia. A postural tremor may accompany the typical features of CIDP and is often treatment refractory.
• #46: In contrast with GBS, CIDP usually spares the cranial nerves, respiratory muscles, and autonomic function. Patients reach clinical nadir more than 2 months after symptom onset. The disease course may be monophasic, relapsing remitting, or progressive.
• #48: to screen for a monoclonal gammopathy. Monoclonal gammopathies can be associated with CIDP. Other demyelinating neuropathies associated with hematologic malignancies are Waldenstrom’s macroglobulinemia and osteosclerotic myeloma in polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes, both of which portend a poorer prognosis and require a different treatment approach. Laboratory testing to exclude alternative causes of neuropathy such as
• #49: CSF analysis is not required for all cases of CIDP, but when collected also classically demonstrates cytoalbuminologic dissociation. MRI may demonstrate contrast enhancing, hypertrophied nerve roots, plexuses, and proximal peripheral nerves. There are more than 15 electrodiagnostic criteria published for CIDP. The European Federation of Neurologic Societies/Peripheral Nerve Society criteria are recommended, given their well-balanced sensitivity and specificity and high diagnostic accuracy.
• #50: There are 3 first-line treatments for CIDP including IVIg, subcutaneous immune globulins, and corticosteroids. Plasma exchange is considered second line given the logistical challenges of administering it chronically in the outpatient setting. IVIg is typically administered at a 2 g/kg dose divided over 2 to 5 days, followed by every 3 to 4 week doses of approximately 1 g/kg. The dose and frequency should constantly be assessed and adjusted depending on treatment response. Subcutaneous immune globulins is administered at a dose of 0.4 g/kg/wk for 5 weeks followed by maintenance dose of either 0.2 or 0.4 g/kg weekly. The PATH study led to its approval by the US Food and Drug Administration in 2018. Corticosteroids (prednisone at a daily dose of 1–1.5 g/kg, high-dose dexamethasone 40 mg/d for 4 days every 4 weeks, or IV methylprednisolone weekly) are options for induction therapy. Three months may be necessary for corticosteroids to be efficacious. Once there is clinical improvement, corticosteroids should be tapered.
• #51: There are 3 first-line treatments for CIDP including IVIg, subcutaneous immune globulins, and corticosteroids. Plasma exchange is considered second line given the logistical challenges of administering it chronically in the outpatient setting. IVIg is typically administered at a 2 g/kg dose divided over 2 to 5 days, followed by every 3 to 4 week doses of approximately 1 g/kg. The dose and frequency should constantly be assessed and adjusted depending on treatment response. Subcutaneous immune globulins is administered at a dose of 0.4 g/kg/wk for 5 weeks followed by maintenance dose of either 0.2 or 0.4 g/kg weekly. The PATH study led to its approval by the US Food and Drug Administration in 2018. Corticosteroids (prednisone at a daily dose of 1–1.5 g/kg, high-dose dexamethasone 40 mg/d for 4 days every 4 weeks, or IV methylprednisolone weekly) are options for induction therapy. Three months may be necessary for corticosteroids to be efficacious. Once there is clinical improvement, corticosteroids should be tapered.
• #52: Plasma exchange is considered in refractory disease with 5 to 10 exchanges over 2 to 4 weeks followed by 1 to 2 sessions every 3 to 4 weeks. Steroid-sparing agents such as mycophenolate mofetil and azathioprine are often used to facilitate tapering of corticosteroids. In patients refractory to these approaches, pulse intravenous cyclophosphamide 1 g/m2 monthly for 6 months may be effective. The dose should be assessed and appropriately modified based on nadir white blood cell counts.
• #53: Plasma exchange is considered in refractory disease with 5 to 10 exchanges over 2 to 4 weeks followed by 1 to 2 sessions every 3 to 4 weeks. Steroid-sparing agents such as mycophenolate mofetil and azathioprine are often used to facilitate tapering of corticosteroids. In patients refractory to these approaches, pulse intravenous cyclophosphamide 1 g/m2 monthly for 6 months may be effective. The dose should be assessed and appropriately modified based on nadir white blood cell counts.
• #54: The patient presented with left hand weakness upon waking up in the morning. Months later, she realized she has difficulty pressing the gas pedal or the brakes completely with her right foot. On examination, she had a left finger and wrist drop as well as right foot drop (Fig. 3). Electrodiagnostic studies confirmed conduction blocks of multiple motor nerves at noncompressive sites suggesting a diagnosis of multifocal motor neuropathy (MMN).
• #56: The progressive finger and hand weakness resulted in trouble with activities of daily living. He reported mild numbness in the feet, but no paresthesia or neuropathic pain. He denied bowel, bladder, or bulbar dysfunction. On examination the patient had symmetric weakness of his proximal and distal lower extremities (Medical Research Council grade 4/5 throughout, except dorsiflexion was a 3/5). Pinprick sensation was decreased to the level of the knees and hands. Vibratory sensation was absent to the level of the ankles and normal in the fingers. He was areflexic.
• #60: CIDP is the most common, chronic autoimmune polyneuropathy. The estimated incidence is 0.33 per 100,000 and prevalence 2.81 per 100,000.21 Both cellular and humoral mechanisms are involved
• #63: IVIg is clearly the first choice treatment for MMN. Subcutaneous immune globulins is also likely beneficial. Cyclophosphamide and rituximab are considered only in the setting of treatment refractory disease. Corticosteroids are ineffective and have been reported to worsen disease
• #64: A 40-year-old man presented as a second opinion for CIDP. He developed numbness of the soles of his feet acutely approximately 6 months before presentation. Over the following 2 months, the numbness ascended his legs and into his hands, followed by progressive weakness, resulting in a steppage gait. His initial electrodiagnostic studies demonstrated a demyelinating neuropathy and he was started on IVIg. Despite repeated doses, his weakness progressed, resulting in needing a rolling walker and then a wheelchair. He was treated with several doses of intravenous methylprednisolone followed by 60mg of prednisone dailywithout improvement. He lacked bulbar or autonomic dysfunction. His CSF protein was 733 mg/dL with 3 white blood cells per high power field.
• #66: CIDP is the most common, chronic autoimmune polyneuropathy. The estimated incidence is 0.33 per 100,000 and prevalence 2.81 per 100,000.21 Both cellular and humoral mechanisms are involved
• #67: One-half of patients have typical CIDP, which is characterized by symmetric, proximal, and distal generalized weakness; distal large fiber sensory impairment; and areflexia. A postural tremor may accompany the typical features of CIDP and is often treatment refractory.
• #69: There are 3 first-line treatments for CIDP including IVIg, subcutaneous immune globulins, and corticosteroids. Plasma exchange is considered second line given the logistical challenges of administering it chronically in the outpatient setting. IVIg is typically administered at a 2 g/kg dose divided over 2 to 5 days, followed by every 3 to 4 week doses of approximately 1 g/kg. The dose and frequency should constantly be assessed and adjusted depending on treatment response. Subcutaneous immune globulins is administered at a dose of 0.4 g/kg/wk for 5 weeks followed by maintenance dose of either 0.2 or 0.4 g/kg weekly. The PATH study led to its approval by the US Food and Drug Administration in 2018. Corticosteroids (prednisone at a daily dose of 1–1.5 g/kg, high-dose dexamethasone 40 mg/d for 4 days every 4 weeks, or IV methylprednisolone weekly) are options for induction therapy. Three months may be necessary for corticosteroids to be efficacious. Once there is clinical improvement, corticosteroids should be tapered.