Study guide
4.4 ALS, GBS, CIDP & Neuromuscular Disease Rehab
ABPMR Physical Medicine and Rehabilitation Board Exam Study Guide Exam
Track your progress as you read
Finished sections get a check mark.
1 Chapter 1: Introduction & Exam Overview
1.1 ABPMR Part I Exam Overview & Format 1.2 Board Review Strategy & Content Blueprint Breakdown
2 Chapter 2: Musculoskeletal Medicine
2.1 Shoulder & Upper Extremity Diagnostics 2.2 Knee, Hip & Lower Extremity Conditions 2.3 Spine Pathology, Radiculopathy & Myelopathy 2.4 Inflammatory Arthritis, Tendinopathies & Concussion 2.5 Bone Health, Osteoporosis & Metabolic Bone Disease 2.6 Thoracic Outlet Syndrome & Peripheral Nerve Entrapment 2.7 Fracture Rehabilitation & Immobilization Complications 2.8 Overuse Tendinopathies & Regenerative Medicine 2.9 Gait Analysis & Abnormal Gait Patterns
3 Chapter 3: Spinal Cord Injury Rehabilitation
3.1 ASIA Examination & Impairment Scale 3.2 Spinal Cord Injury Syndromes 3.3 Autonomic Dysreflexia & Acute Complications 3.4 Neurogenic Bladder, Bowel & Secondary Complications
4 Chapter 4: Stroke & Neuromuscular Rehabilitation
4.1 Stroke Vascular Syndromes & Acute Assessment 4.2 Stroke Motor Recovery & Hemiplegic Complications 4.3 Spasticity Assessment & Multimodal Management 4.4 ALS, GBS, CIDP & Neuromuscular Disease Rehab 4.5 Multiple Sclerosis & Demyelinating Disease Rehabilitation 4.6 Parkinsonism, Movement Disorders & Functional Neurologic Disorder
5 Chapter 5: Electrodiagnostics (EMG/NCS)
5.1 Nerve Conduction Studies Principles & Physics 5.2 Needle Electromyography & MUAP Analysis 5.3 Mononeuropathies & Radiculopathy Patterns 5.4 Neuromuscular Junction Disorders & Myopathies
6 Chapter 6: Traumatic Brain Injury
6.1 TBI Severity Classification, Glasgow Coma Scale, and Pathophysiology 6.2 Rancho Los Amigos Levels of Cognitive Functioning and Disability Rating Scale 6.3 Neurobehavioral Sequelae and Agitation Management 6.4 Concussion Evaluation, Vestibular-Ocular Dysfunction, and Return-to-Play/Work Protocols
7 Chapter 7: Chronic Pain & Interventional Spine
7.1 Fluoroscopic Spine Interventions 7.2 Opioid Stewardship & Controlled Substance Compliance 7.3 Complex Regional Pain Syndrome, Fibromyalgia & Myofascial Pain 7.4 Spinal Cord Stimulation & Intrathecal Therapy
8 Chapter 8: Amputee Rehabilitation & Prosthetics
8.1 Amputation Surgical Levels & Medicare K-Levels 8.2 Socket Designs & Suspension Systems 8.3 Prosthetic Feet & Microprocessor Knee Mechanisms 8.4 Post-Amputation Care, Residual Limb & Phantom Pain
9 Chapter 9: Pediatric Rehabilitation
9.1 Cerebral Palsy Classification & GMFCS 9.2 Spina Bifida & Myelomeningocele Management 9.3 Muscular Dystrophies & Neuromuscular Disease in Children 9.4 Pediatric Brachial Plexopathy & Congenital Disorders
10 Chapter 10: Prosthetics, Orthotics & Assistive Technology
10.1 Lower Limb Orthoses — AFOs & KAFOs 10.2 Spinal & Upper Extremity Orthoses 10.3 Upper Limb Prosthetics — Body-Powered vs Myoelectric 10.4 Wheelchairs, Seating Systems & Pressure Mapping
11 Chapter 11: Medical Rehabilitation & Outcomes
11.1 Dysphagia Assessment & Management 11.2 Neurogenic Bladder & Bowel Management 11.3 Pressure Injuries & Wound Management 11.4 Outcome Measures & Medical Complications 11.5 Cancer Rehabilitation & Oncologic Rehabilitation 11.6 Burns, Endocrine/Metabolic & Medical Complications Rehabilitation
12 Chapter 12: Cardiopulmonary Rehabilitation
12.1 Cardiac Rehabilitation Phases & Metabolic Equivalents 12.2 Pulmonary Rehabilitation & COPD Management
13 Chapter 13: Foundational Rehabilitation Concepts
13.1 Kinesiology, Biomechanics & Functional Anatomy 13.2 Rehabilitation Pharmacology & Medication Management 13.3 Research Methodology, Biostatistics & Evidence-Based Practice 13.4 Nutrition, Metabolism & Energy Expenditure in Rehabilitation 13.5 Diagnostic Procedures: Imaging, MSK Ultrasound, Urodynamics & Neuropsych Assessment
4.4 ALS, GBS, CIDP & Neuromuscular Disease Rehab
Key Takeaways Explain This Topic AI
Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease characterized by simultaneous Upper Motor Neuron (UMN: hyperreflexia, spasticity, Babinski sign) and Lower Motor Neuron (LMN: atrophy, fasciculations, weakness) degeneration across multiple anatomical regions (bulbar, cervical, thoracic, lumbosacral).
Disease-modifying therapies for ALS include riluzole (glutamate excitotoxicity antagonist, extends survival 2-3 months) and edaravone (free radical scavenger); non-invasive ventilation (NIV/BiPAP) is indicated when Forced Vital Capacity (FVC) drops below 50% or Maximal Inspiratory Pressure (MIP) is <60 cmH2O, and gastrostomy (PEG) tube placement should be performed while FVC remains >50% to minimize operative risk.
Guillain-Barré Syndrome (GBS / AIDP) presents as an acute post-infectious (e.g., Campylobacter jejuni) symmetric ascending flaccid paralysis with loss of deep tendon reflexes and cranial nerve involvement; cerebrospinal fluid (CSF) analysis demonstrates classic albuminocytologic dissociation (elevated protein with normal white blood cell count).
Treatment of GBS relies on intravenous immunoglobulin (IVIG) or plasma exchange (PLEX), initiated early in the disease course; systemic corticosteroids are ineffective and not recommended.
Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) differs from GBS by its chronic progressive or relapsing course (>8 weeks) and its clinical responsiveness to corticosteroids in addition to IVIG and PLEX, whereas Myasthenia Gravis (MG) is an autoimmune postsynaptic acetylcholine receptor disorder presenting with fatigable weakness and a decremental response on low-frequency (2-3 Hz) repetitive nerve stimulation (RNS).
Last updated: July 2026
ALS, GBS, CIDP & Neuromuscular Disease Rehab
Neuromuscular disorders encompass pathologies affecting the anterior horn cell, peripheral nerve, neuromuscular junction, and muscle. Physiatrists manage function, mobility, non-invasive ventilation, and adaptive equipment in progressive and acute neuromuscular conditions including Amyotrophic Lateral Sclerosis (ALS) , Guillain-Barré Syndrome (GBS) , Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) , and Myasthenia Gravis (MG) .
Amyotrophic Lateral Sclerosis (ALS)
Amyotrophic Lateral Sclerosis (ALS / Lou Gehrig Disease) is a fatal, rapidly progressive neurodegenerative disease characterized by simultaneous degeneration of Upper Motor Neurons (UMN) in the motor cortex and Lower Motor Neurons (LMN) in the brainstem and anterior horn of the spinal cord.
Clinical Presentation and Diagnostic Features
Combined UMN and LMN Signs : The hallmark of ALS is finding concurrent UMN and LMN deficits in the same anatomical body region:
UMN Signs : Spasticity, hyperreflexia, clonus, extensor plantar responses ( Babinski sign ), and pseudobulbar affect (uncontrollable laughing/crying).
LMN Signs : Muscle weakness, muscular atrophy, fasciculations , muscle cramps, and hypotonia.
Anatomical Regions : Assessed across four body segments: Bulbar (dysarthria, dysphagia, tongue atrophy/fasciculations), Cervical (hand weakness, intrinsic atrophy), Thoracic (trunk weakness, dyspnea), and Lumbosacral (foot drop, leg weakness).
Sparing : Extraocular movements, bowel/bladder sphincters, and sensory pathways are characteristically preserved.
Disease-Modifying Pharmacotherapy
Riluzole : Inhibits presynaptic glutamate release and blocks NMDA receptors, mitigating excitotoxic neuronal injury. It extends median survival by 2 to 3 months . Requires baseline and periodic LFT monitoring.
Edaravone : Intravenous or oral free radical scavenger that reduces oxidative stress, slowing functional decline on the ALS Functional Rating Scale-Revised (ALSFRS-R).
Tofersen : Antisense oligonucleotide that reduces SOD1 protein synthesis in patients with SOD1 gene mutations.
Pulmonary and Nutritional Rehabilitation
Non-Invasive Ventilation (NIV / BiPAP) : Respiratory failure from diaphragmatic weakness is the primary cause of death in ALS. NIV is indicated when:
- Forced Vital Capacity (FVC) < 50% of predicted
- Maximal Inspiratory Pressure (MIP) < 60 cmH2O
Nocturnal desaturation or symptomatic hypercapnia.
Outcome : NIV prolongs survival, slows FVC decline, and improves quality of life far more than any medication.
Percutaneous Endoscopic Gastrostomy (PEG) Timing : Dysphagia leads to severe malnourishment and dehydration. PEG tube placement should be performed early while the patient's FVC remains > 50% . When FVC drops below 50%, perioperative respiratory failure and procedure-related mortality rise sharply.
Exercise Guidelines : Moderate submaximal aerobic exercise and light resistive training are beneficial in early stages. Clinicians must strictly avoid eccentric contractions and high-intensity exhaustive exercise , which cause overwork weakness and irreversible myofiber breakdown in denervated motor units.
Guillain-Barré Syndrome (GBS / AIDP)
Guillain-Barré Syndrome (GBS) , most commonly manifesting as Acute Inflammatory Demyelinating Polyneuropathy (AIDP) , is an acute, post-infectious autoimmune polyradiculoneuropathy.
Clinical Presentation and Diagnostics
Etiology : Triggered 1 to 3 weeks prior by respiratory or gastrointestinal infection. The most common inciting pathogen is Campylobacter jejuni (associated with severe axonal variants), followed by Cytomegalovirus (CMV), Epstein-Barr Virus (EBV), and Mycoplasma pneumoniae .
Clinical Features : Rapidly progressive, symmetric ascending flaccid paralysis , beginning in the lower extremities and ascending to the trunk, upper extremities, and cranial nerves (facial diplegia in 50%). Areflexia (loss of DTRs) is obligatory. Autonomic instability (labile blood pressure, cardiac arrhythmias, paralytic ileus) is common and life-threatening.
Diagnostic Findings :
CSF Analysis : Demonstrates albuminocytologic dissociation —a classic hallmark characterized by markedly elevated CSF protein levels (>45 mg/dL) with a normal CSF white blood cell count (<10 cells/μL) . Protein elevation may take 7 to 14 days post-onset to develop.
NCS/EMG : Features of primary demyelination: prolonged distal motor latencies, marked conduction velocity slowing (<75% of lower limit of normal), conduction block, temporal dispersion, and prolonged or absent F-waves (reflecting demyelination at the proximal spinal roots).
Disease-Modifying Medical Management
First-Line Immunotherapies :
Intravenous Immunoglobulin (IVIG) : 0.4 g/kg/day IV for 5 consecutive days.
Plasma Exchange (PLEX) : 4 to 5 plasma exchanges over 7 to 14 days.
Comparison : IVIG and PLEX are equally effective in shortening time to recovery and ventilator dependence. Combining IVIG and PLEX provides no added clinical benefit.
Corticosteroids : Systemic corticosteroids ARE NOT EFFECTIVE in GBS and are explicitly contraindicated , as randomized trials show they do not speed recovery and may worsen long-term outcomes.
Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) is an autoimmune demyelinating polyneuropathy considered the chronic counterpart of GBS.
Clinical Distinction from GBS : CIDP follows a progressive or relapsing-remitting course lasting greater than 8 weeks (whereas GBS reaches peak disability within 4 weeks). It produces symmetric proximal and distal weakness with generalized areflexia.
Therapeutic Difference : Unlike GBS, CIDP responds robustly to systemic corticosteroids (prednisone) . First-line treatments include corticosteroids, IVIG, and PLEX , often requiring long-term maintenance immunosuppression (e.g., azathioprine, rituximab).
Myasthenia Gravis (MG)
Myasthenia Gravis (MG) is an autoimmune disorder of the neuromuscular junction caused by autoantibodies targeting postsynaptic structures.
Pathophysiology and Clinical Presentation
Autoantibodies : 85% of cases exhibit autoantibodies against postsynaptic acetylcholine receptors (AChR) ; remaining cases may have antibodies against muscle-specific kinase (MuSK) . Up to 15% of patients have an underlying thymoma , and 70% have thymic hyperplasia.
Clinical Hallmarks : Fatigable muscle weakness that worsens with repetitive activity and toward the end of the day, improving with rest. Initial symptoms affect extraocular muscles ( ptosis, diplopia ), progressing to bulbar weakness (dysphagia, dysarthria) and limb/respiratory muscle weakness.
Condition Target Pathology Diagnostic Hallmarks Key First-Line Medical Treatments Unique Management Pearls
ALS UMN (cortex) + LMN (anterior horn) Combined UMN & LMN signs in same region Riluzole, Edaravone PEG tube placement while FVC > 50% ; NIV when FVC < 50%
GBS (AIDP) Peripheral nerve myelin & spinal roots Albuminocytologic dissociation (high protein, normal WBC) IVIG or PLEX Corticosteroids are NOT effective ; monitor for autonomic instability
CIDP Chronic peripheral demyelination Progressive/relapsing weakness >8 weeks Corticosteroids , IVIG, or PLEX Responds well to oral corticosteroids (unlike GBS)
Myasthenia Gravis Postsynaptic AChR at neuromuscular junction Decremental CMAP response on low-frequency (2–3 Hz) RNS Pyridostigmine, immunosuppression, IVIG/PLEX Thymectomy for thymoma/generalized MG; avoid aminoglycosides
Diagnostic Electrodiagnostics
Repetitive Nerve Stimulation (RNS) : Low-frequency (2–3 Hz) stimulation demonstrates a classic decremental response (>10% drop in CMAP amplitude) between the 1st and 4th stimuli due to depletion of presynaptic ACh vesicles across compromised postsynaptic receptors.
Single-Fiber EMG (SFEMG) : The most sensitive diagnostic test (>95%), revealing increased jitter (variability in inter-potential intervals) and neuromuscular blocking.
Medical and Surgical Management
Acetylcholinesterase Inhibitors : Pyridostigmine provides symptomatic benefit by prolonging ACh availability in the synaptic cleft.
Immunosuppression & Crisis : Corticosteroids, azathioprine, or mycophenolate for chronic control; IVIG or PLEX for acute myasthenic crisis.
Thymectomy : Indicated for all patients with thymoma, and recommended in non-thymomatous generalized AChR-positive MG to induce long-term remission.