CCPT311-8-Polio-GBS-XX

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Anterior Horn Cell and Spinal Muscular Atrophy (SMA)

  • Group of disorders associated with lower motor neuron (LMN) loss

  • Degeneration of anterior horn cells in the spinal cord

  • Presents with proximal muscle weakness and atrophy

  • Etiology: Homozygous deletion at 5q13 responsible for 95% of cases of SMA

  • Most common subtype: Proximal SMA (Type 0, 1, 2, 3, 4)

  • Prevalence: 1 in 6,000-11,000, carrier frequency of 1 in 40 in the general population

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Types of SMA

  • Type 0: Congenital SMA, presents in the neonatal period with hypotonia and early respiratory failure

  • Type I: Acute Werdnig-Hoffman Disease, non-sitters with limited head control and hypotonia

  • Type II: Chronic Werdnig-Hoffman Disease, sitters with progressive weakness and scoliosis

  • Type III: Kugelberg-Welander Disease, walkers with mild weakness

  • Type IV: Adult onset SMA, presents in adulthood with mild leg weakness

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Type III: Kugelberg-Welander Disease

  • Presents after 18 months with progressive weakness

  • Similar to Type II but without restrictive lung disease

  • Subtypes: Type IIIa (18 months to 3 years), Type IIIb (>3 years)

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Diagnosis and Management of SMA

  • Diagnosis: Electrodiagnostic testing shows motor loss consistent with loss of motor neuron function

  • Management:

    • Spinaraza (Nusinersen): Intrathecal delivery of antisense oligonucleotide (ASO) to promote functional SMN2 production

    • Onasemnogene Abeparvovec: One-time IV injection gene therapy to deliver the SMN1 gene

    • Risdiplam: Oral medication that increases functional SMN protein levels

  • Pulmonary, gastrointestinal, and orthopedic management strategies discussed

  • Differential Diagnosis: Spinobulbar Muscular Atrophy, a slowly progressive LMN syndrome with bulbar involvement and sensory neuropathy

Page 5: Poliomyelitis

  • Poliomyelitis is a viral disease that can range in severity from self-limiting disease to meningitis.

  • In its most severe form, it may present as acute flaccid paralysis.

  • Poliovirus is the virus causing both acute polio and post-polio syndrome (PPS).

  • The primary cause of the majority of the world's paralytic polio cases until vaccines became widespread is Wild Type 1 Poliovirus.

  • Wild Types 2 & 3 have been eradicated as of 2015.

  • Prevention methods include the Salk vaccine (inactivated polio vaccine) and the Sabin vaccine (attenuated oral polio vaccine).

  • The primary infection can lead to viral replication in oropharyngeal and gastrointestinal lymphatic tissues.

  • In up to 95% of cases, infections are non-paralytic, presenting as a flu-like illness.

  • In approximately 5% of cases, pure motor paralysis can occur.

Page 6: Poliomyelitis continued

  • Poliomyelitis is commonly transmitted through the oral-fecal route.

  • Oral-oral spread is also possible.

  • Clinical manifestations of poliomyelitis include pure motor deficit, headaches, myalgias, fatigue, nausea, neck stiffness, or pharyngitis.

  • It can progress into the spinal cord, causing severe muscle spasms and asymmetrical flaccid paralysis.

  • Poliomyelitis tends to have a lower-limb predominance.

  • The acute stage of poliomyelitis lasts for 2 years, followed by a stage of recovery that lasts for more than 2 years.

  • Rehabilitation plays an imperative role in preventing the development of deformities.

  • During the stage of recovery, non-fatiguing exercise programs are appropriate to deal with muscle weakness.

Page 7: Poliomyelitis and Post-Polio Syndrome

  • The stage of chronicity in poliomyelitis is characterized by recovery of muscle plateau and residual paralysis.

  • Approximately 60-80% of patients with a past diagnosis of polio report at least 1 fall in the past year.

  • Diagnosis of poliomyelitis is made through various tests such as blood, CSF, respiratory, stool tests, EMG, and brain/SC MRI to rule out other pathologies.

  • Post-Polio Syndrome (PPS) affects approximately 30-40% of polio patients.

  • PPS progression is multifactorial and depends on factors like severity of acute paralysis, age of onset, and socio-economic status.

  • PPS is not contagious and is characterized by the onset of new muscle weakness and persistent symptoms for at least 1 year.

  • Diagnosis of PPS is made by exclusion, as there are no definitive biomarkers widely accepted.

Page 8: Myasthenia Gravis

  • Myasthenia Gravis (MG) is an autoimmune disorder that affects the neuromuscular junction of the skeletal muscles.

  • It is more common among patients with a history of thymoma or tumor on the thymus.

  • MG is more prevalent in females than males and affects individuals over 50 years old.

  • Clinical manifestations of MG include fluctuating weakness, extraocular muscle weakness, diplopia, bulbar muscle weakness, limb weakness, and myasthenic crisis.

  • Diagnosis of MG can be done through the Edrophonium (Tensilon) Test, which is a short-acting acetylcholinesterase inhibitor that increases the availability of ACh in the neuromuscular junction.

  • Another quick bedside technique for diagnosing MG is placing a small cube of ice over the ptotic eyelid for 2 minutes, which can indicate a disorder of neuromuscular transmission.

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Clinical Correlation in Physical Therapy - Poliomyelitis & Guillain Barre Syndrome Management

  • Acetylcholinesterase inhibitors increase the level of ACh at the NMJ by preventing its enzymatic degradation.

    • Neostigmine

    • Pyridostigmine

    • Physostigmine

  • Immunosuppressive Treatment

  • Intravenous immunoglobulins (IVIG)/Plasmapheresis

  • Thymectomy

Cholinergic Crisis

  • Overstimulation at a NMJ due to an excess of Ach

  • Weakness due to drug intake due to accumulation of Ach in the synaptic cleft.

Lambert Eaton Myasthenic Syndrome (LEMS)

  • Fluctuating weakness that improves with exercise.

  • Paraneoplastic Phenomenon or Primary Autoimmune disorder.

  • Underlying malignancy, most commonly small-cell lung cancer.

  • Affects voltage-gated Ca channels in the presynaptic membrane.

Epidemiology

  • LEMS is 46 times less prevalent than Myasthenia Gravis (MG).

  • More common in males (75% of patients are males).

  • Poor prognosis.

  • Peak age of onset at 35 years and a second larger peak at 60 years.

Clinical Manifestation

  • Muscle weakness:

    • Proximal to Distal; Caudal to Cranial.

    • Lower extremities more affected than upper extremities.

    • Symmetrical pattern of progression - proximal to distal, and caudal to cranial, finally reaching the oculobulbar region.

    • Dull aching or stiffness.

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Clinical Correlation in Physical Therapy - Poliomyelitis & Guillain Barre Syndrome

  • Areflexia is present in the absence of significant muscle atrophy.

  • Postexercise or post-activation facilitation characterized by the return of tendon reflexes and muscle strength with repeated muscle contractions.

  • Oculobulbar Weakness:

    • 70% of patients.

    • Ocular symptoms, particularly ptosis and diplopia.

    • Dysphagia and dysarthria are seen in later stages of the disease.

  • Autonomic dysfunction is reported in 80-96% of patients.

    • Most common symptom: Dry mouth.

    • Other symptoms: Erectile dysfunction, constipation, orthostatic dysfunction, altered perspiration.

  • Respiratory failure infrequently occurs in the later stages.

  • Triad of LEMS:

    • Areflexia

    • Muscle weakness with a typical distribution

    • Autonomic dysfunction.

Management

  • Drug of choice: Guanidine

  • Oral medication used to treat the symptoms of LEMS.

Botulism

  • Rare, potentially fatal syndrome of diffuse, flaccid paralysis caused by botulinum neurotoxin (BoNT) elaborated by the bacterium Clostridium botulinum.

  • Mode of Transmission: Foodborne botulism is acquired by the ingestion of inadequately cooked food or processed or refrigerated foods in which toxin has formed, particularly canned and alkaline foods.

Epidemiology

  • Average of 162 annual cases of botulism.

  • Distribution:

    • 71-88% for infant botulism

    • 1-20% for foodborne botulism

    • 5-10% for wound botulism

    • 1-4% for botulism of other or unknown origin.

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Clinical Correlation in Physical Therapy - Poliomyelitis & Guillain Barre Syndrome

  • Overall mortality was 3.0% with 109 botulism-related deaths among 3,618 botulism cases.

Total Nerve Blockage

  • Classically begins with cranial nerve palsies.

    • Diplopia (visual disturbances), dysphagia (difficulty swallowing), dysphonia (voice change), and dysarthria (slurred speech).

  • Progresses to symmetrical descending weakness of the trunk, extremities, and smooth muscle, with eventual flaccid paralysis.

  • No sensory deficits except for blurred vision, although paresthesias are occasionally seen.

Medication

  • Heptavalent Botulinum Antitoxin (HBAT)

  • Mixture of immune globulin fragments indicated for the treatment of symptomatic botulism following documented or suspected exposure to botulinum neurotoxin.

Immune Mediated Neuropathy - Guillain-Barre Syndrome (GBS)

  • Also known as "Landry's Paralysis"

  • Demyelinating Disease of the Peripheral Nervous System.

  • Acute inflammatory demyelinating polyneuropathy/post-infectious immune-mediated (IgG) neuropathy.

  • Most common cause of acute flaccid paralysis.

  • Idiopathic but self-limiting.

  • Progressive symmetrical weakness of the limbs with hyporeflexia or areflexia, with or without sensory abnormalities.

  • Numbness, tingling, and weakness that can progress to paralysis.

Epidemiology

  • Rare but affects 0.4 to 2 per 100,000 individuals.

  • More common in males.

  • Approximately 100,000 patients worldwide.

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Clinical Correlation in Physical Therapy - Poliomyelitis & Guillain Barre Syndrome

Etiology/Pathology

  • Molecular mimicry:

    • Campylobacter jejuni: Lipooligosaccharide of Campylobacter jejuni is similar to the gangliosides of peripheral nerve membranes.

    • Cytomegalovirus

    • Epstein Bar Virus

  • Post-infection: Most common antecedent illnesses are gastrointestinal or respiratory illnesses.

    • 70% of patients have reported an antecedent illness in the 1-6 weeks before the presentation of GBS.

Clinical Manifestation

  • Ascending Symmetrical Weakness

  • Monophasic (not relapsing or remitting course)

  • 1-6 weeks of antecedent illness.

  • Non-length-dependent sensory symptoms (dysesthesias in the hands followed by the feet)

  • Facial diplegia due to the involvement of both facial cranial nerves.

  • Dysphagia due to the involvement of glossopharyngeal, vagus, and hypoglossal cranial nerves.

  • Dysautonomia is a primary etiology of the morbidity and mortality attributable to GBS.

  • Respiratory failure can occur in up to 30% of patients, usually leading to prolonged hospitalization and recovery.

Diagnosis

  • Lumbar Puncture

    • Normal within 48 hours

    • Elevated CSF protein (>0.55 g/dL) by the end of the week.

  • Electrodiagnostic Testing

    • Confirmatory test for GBS and can differentiate between the more common demyelinating form (AIDP) and axonal forms (AMAN and AMSAN).

    • Main clinical method of distinguishing subtypes.

Page 13: Clinical Correlation in Physical Therapy - Poliomyelitis & Guillain Barre Syndrome

  • GBS subtypes:

    • Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP)

      • Primarily motor inflammatory demyelination or secondary axonal damage

      • Clinical features: symmetrical weakness of all limbs, hyporeflexia, mild sensory symptoms, respiratory involvement, facial nerve palsy

    • Acute Motor-Sensory Axonal Neuropathy (AMSAN)

      • Motor and sensory involvement with severe course respiratory and bulbar involvement

      • Primary axonal degeneration with poorer prognosis

      • Similar to AMAN but affects sensory nerves and roots

    • Acute Motor Axonal Neuropathy (AMAN)

      • Primary axonal degeneration

      • Motor only with early and severe respiratory involvement

      • Often affects children and young adults

    • Miller-Fisher Variant

    • Pharyngeal-cervical-brachial variant of GBS

    • Acute Pandysautonomia

Page 14: Clinical Correlation in Physical Therapy - Poliomyelitis & Guillain Barre Syndrome

  • Miller-Fisher Syndrome:

    • Triad: ophthalmoplegia, sensory ataxia, areflexia

    • Rare disorder

    • Sensory loss unusual, but proprioception may be impaired

    • Demyelination and inflammation of CN 3 & 6, spinal ganglia, and peripheral nerves

    • Resolution: 1-3 months

  • Pharyngeal-cervical-brachial variant:

    • Often associated with IgG anti-GT1a

    • Presents with proximal descending weakness

    • Must distinguish from botulism and diphtheria

  • Acute Panautonomic Neuropathy:

    • Rarest variant

    • Widespread sympathetic and parasympathetic failure

    • Involvement of SNS & PNS

    • Cardiovascular involvement: postural hypotension, tachycardia, HTN, dysrhythmias

  • Autonomic dysfunctions:

    • Sinus tachycardia or bradycardia

    • Fluctuating HTN or hypotension

    • Flushing of the face

    • Loss of or excessive sweating

  • Bickerstaff Brainstem Encephalitis:

    • Ophthalmoplegia, ataxia, areflexia, pyramidal tract signs, and impaired consciousness, often overlapping with sensorimotor GBS

  • GBS variants: pattern of symptoms management

    • Intravenous Immunoglobulin (IVIG) or Plasma Exchange

    • 5% of patients achieving independent ambulation with