Carbamate toxicity
Mushroom toxicity, especially:
Amanita muscaria
Inocybe
Clitocybe<unk> 
Nerve agent
Sarin
VX
Novichok agent
Nicotine toxicity (look alike)
Acetylcholinesterase inhibitor overdose (e.g in myasthenia gravis or post anesthesia reversal)
Amanita muscaria
Inocybe
Clitocybe
Sarin
VX
Novichok agent
Neuromuscular weakness
Upper motor neuron:
CVA
Hemorrhagic stroke
Multiple sclerosis
Amyotrophic Lateral Sclerosis (ALS) (UMN & LMN)
Lower motor neuron:
Spinal and bulbar muscular atrophy (Kennedy's syndrome)
Spinal cord disease:
Infection (Epidural abscess)
Infarction/ischemia
Trauma (Spinal Cord Syndromes)
Inflammation (Transverse Myelitis)
Acute flaccid myelitis
Degenerative (Spinal muscular atrophy)
Tumor
Peripheral nerve disease:
Guillain-Barre syndrome
Toxins (Ciguatera)
Tick paralysis
Diabetic peripheral neuropathy
NMJ disease:
Myasthenia gravis crisis
Botulism<unk> 
Lambert-Eaton myasthenic syndrome
Muscle disease:
Rhabdomyolysis
Dermatomyositis
Polymyositis
Alcoholic myopathy
Non-neuromuscular weakness
Can't miss diagnoses:
ACS
Arrhythmia/Syncope
Severe infection/Sepsis
Hypoglycemia
Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
Hypokalemic periodic paralysis
Thyrotoxic periodic paralysis
Respiratory failure
Emergent Diagnoses:
Symptomatic Anemia
Severe dehydration
Hypothyroidism
Polypharmacy
Malignancy
Other causes of weakness and paralysis
Acute intermittent porphyria (ascending weakness)
Upper motor neuron:
CVA
Hemorrhagic stroke
Multiple sclerosis
Amyotrophic Lateral Sclerosis (ALS) (UMN & LMN)
Lower motor neuron:
Spinal and bulbar muscular atrophy (Kennedy's syndrome)
Spinal cord disease:
Infection (Epidural abscess)
Infarction/ischemia
Trauma (Spinal Cord Syndromes)
Inflammation (Transverse Myelitis)
Acute flaccid myelitis
Degenerative (Spinal muscular atrophy)
Tumor
Peripheral nerve disease:
Guillain-Barre syndrome
Toxins (Ciguatera)
Tick paralysis
Diabetic peripheral neuropathy
NMJ disease:
Myasthenia gravis crisis
Botulism<unk> 
Lambert-Eaton myasthenic syndrome
Muscle disease:
Rhabdomyolysis
Dermatomyositis
Polymyositis
Alcoholic myopathy
CVA
Hemorrhagic stroke
Multiple sclerosis
Amyotrophic Lateral Sclerosis (ALS) (UMN & LMN)
Spinal and bulbar muscular atrophy (Kennedy's syndrome)
Infection (Epidural abscess)
Infarction/ischemia
Trauma (Spinal Cord Syndromes)
Inflammation (Transverse Myelitis)
Acute flaccid myelitis
Degenerative (Spinal muscular atrophy)
Tumor
Acute flaccid myelitis
Guillain-Barre syndrome
Toxins (Ciguatera)
Tick paralysis
Diabetic peripheral neuropathy
Myasthenia gravis crisis
Botulism<unk> 
Lambert-Eaton myasthenic syndrome
Rhabdomyolysis
Dermatomyositis
Polymyositis
Alcoholic myopathy
Can't miss diagnoses:
ACS
Arrhythmia/Syncope
Severe infection/Sepsis
Hypoglycemia
Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
Hypokalemic periodic paralysis
Thyrotoxic periodic paralysis
Respiratory failure
Emergent Diagnoses:
Symptomatic Anemia
Severe dehydration
Hypothyroidism
Polypharmacy
Malignancy
Other causes of weakness and paralysis
Acute intermittent porphyria (ascending weakness)
ACS
Arrhythmia/Syncope
Severe infection/Sepsis
Hypoglycemia
Periodic paralysis (electrolyte disturbance, K, Mg, Ca)
Hypokalemic periodic paralysis
Thyrotoxic periodic paralysis
Respiratory failure
Hypokalemic periodic paralysis
Thyrotoxic periodic paralysis
Symptomatic Anemia
Severe dehydration
Hypothyroidism
Polypharmacy
Malignancy
Acute intermittent porphyria (ascending weakness)
Blister chemical agents (Vesicants)
Lewisite (L)
Sulfur mustard (H)
Phosgene oxime (CX)
Pulmonary chemical agents (Choking agents)
Ammonia toxicity
Methyl isocyanate
Methyl bromide
Hydrochloric acid
Chlorine gas
Phosgene
Incendiary agents
Agent orange
White phosphorus
Cyanide chemical weapon agents (Blood agents)
Prussic acid (AKA hydrogen cyanide, hydrocyanic acid, or formonitrile)
Nerve Agents<unk> s)
Acetylcholinesterase inhibitors
Household and commercial pesticides (diazinon and parathion)
G-series (sarin, tabun, soman)
V-series (VX)
Lacrimating or riot-control agents
Pepper spray
Chloroacetophenone
CS
Lewisite (L)
Sulfur mustard (H)
Phosgene oxime (CX)
Ammonia toxicity
Methyl isocyanate
Methyl bromide
Hydrochloric acid
Chlorine gas
Phosgene
Agent orange
White phosphorus
Prussic acid (AKA hydrogen cyanide, hydrocyanic acid, or formonitrile)
Acetylcholinesterase inhibitors
Household and commercial pesticides (diazinon and parathion)
G-series (sarin, tabun, soman)
V-series (VX)
Pepper spray
Chloroacetophenone
CS
Cardiac
Inferior MI (involving RCA)
Sick sinus syndrome
Neurocardiogenic/reflex-mediated
Increased ICP
Vasovagal reflex
Hypersensitive carotid sinus syndrome
Intra-abdominal hemorrhage (i.e. ruptured ectopic)
Metabolic/endocrine/environmental
Hyperkalemia
Hypothermia (Osborn waves on ECG)
Hypothyroidism
Myxedema coma
Hypoglycemia (neonates)
Toxicologic
B-blocker
Ca-channel blocker
Digoxin toxicity
Opioids<unk> s
Ethanol
Clonidine
Infectious/Postinfectious
Chagas disease
Lyme disease
Syphilis
Other
Brash syndrome
Inferior MI (involving RCA)
Sick sinus syndrome
Increased ICP
Vasovagal reflex
Hypersensitive carotid sinus syndrome
Intra-abdominal hemorrhage (i.e. ruptured ectopic)
Hyperkalemia
Hypothermia (Osborn waves on ECG)
Hypothyroidism
Myxedema coma
Hypoglycemia (neonates)
Myxedema coma
B-blocker
Ca-channel blocker
Digoxin toxicity
Opioids<unk> s
Ethanol
Clonidine
Chagas disease
Lyme disease
Syphilis
Brash syndrome
Organophosphate toxicity
Carbamate toxicity
Salicylate toxicity
Mushroom toxicity, especially:
Chlorate toxicity
Amanita muscaria
Thallium toxicity
Inocybe