Vitamins
Electrodiagnostics
Toxic neuropathies
Clinica Scenarios
Medications causing neuropathies
100
Loss of vibration and proprioception accompanied by spasticity should immediately raise concern for deficiency of these two nutrients.
What is vitamin B12 deficiency ?
100
This is the most common pattern seen in nutritional neuropathies.
What is a length-dependent, sensory-predominant axonal polyneuropathy?
100
This is the most common cause of toxic peripheral neuropathy worldwide.
What is chronic alcohol use?
100
A 46-year-old battery factory worker presents with progressive hand weakness and bilateral wrist drop, along with abdominal pain and constipation. Examination shows predominant weakness of wrist and finger extensors with relatively preserved sensation. Labs reveal microcytic anemia with basophilic stippling.
What is lead toxicity?
100
This anti seizure medication is often first line to treat neuropathic pain. Describe its mechanism.
What its binding to alpha-2-delta subunit of voltage-gated calcium channels in the central nervous system?
200
Antibodies against this component have being associated with vitamin B12 deficiency and pernicious anemia causing neuropathy.
What is Intrinsic factor?
200
On nerve conduction studies, this finding is typically seen first in axonal neuropathies.
What is reduced sensory nerve action potential (SNAP) amplitude?
200
This chemotherapeutic agent is classically associated with a dose-dependent, painful, length-dependent sensory axonal neuropathy.
What is oxaliplatin? (Cisplatin or paclitaxel would also be acceptable.)
200
A 42-year-old mining worker presents with distal paresthesias, tremor, irritability, and gait imbalance after years of occupational exposure to this heavy metal. Examination shows decreased distal sensation and impaired vibration. His skin appears like this:
What is mercury poisoning?
200
This antimicrobial, commonly prescribed for urinary tract infections, may cause a length-dependent sensorimotor neuropathy, particularly in patients with renal impairment or prolonged use.
What is Nitrofurantoin?
300
This vitamin deficiency can present with progressive altered mental status, ataxia, neuropathy and oculomotor abnormalities
What is Vitamin B1 deficiency
300
A patient with chronic alcohol use undergoes EMG/NCS showing reduced CMAP and SNAP amplitudes with relatively preserved conduction velocities. This pattern is most consistent with:
What is an axonal sensorimotor polyneuropathy?
300
This medication used to treat tuberculosis can cause peripheral neuropathy by interfering with vitamin B6 metabolism.
What is isoniazid (INH)?
300
A patient with progressive sensory ataxia, hyperreflexia, and a history of bariatric surgery has a normal vitamin B12 level. This reversible deficiency should be suspected.
What is Copper deficiency?
300
This group of chemotherapy agents may cause acute inflammatory demyelinating polyradiculoneuropathy.
What is immune check point inhibitors?
What is: el que la saque mal tiene guardia extra?
400
A patient has neuropathy with gait ataxia, dysarthria, and absent reflexes after chronic fat malabsorption. The deficiency is:
What is vitamin E deficiency?
400
In most nutritional and toxic neuropathies, needle EMG of distal muscles demonstrates these two classic abnormalities of chronic axonal injury.
What are fibrillation potentials/positive sharp waves and motor unit changes with reduced recruitment?
400
This antimicrobial, commonly used to treat anaerobic infections and Clostridioides difficile, is associated with a dose- and duration-dependent, predominantly sensory axonal neuropathy.
What is metronidazole?
400
A 45-year-old man presents with painful distal paresthesias and progressive weakness several weeks after a severe gastrointestinal illness after ingesting a drink that was intentionally contaminated by another person.. Examination shows a symmetric length-dependent sensorimotor neuropathy, and skin examination reveals hyperkeratosis and transverse white lines on the fingernails.
What is arsenic poisoning?
400
This antiarrhythmic medication may cause a length-dependent sensorimotor axonal neuropathy with prolonged use.
What is amiodarone?
500
Progressive numbness with preserved strength but non–length-dependent sensory loss after excessive supplement use most strongly suggests toxicity from this vitamin.
What is vitamin B6 (pyridoxine)?
500
A patient with numbness and gait imbalance has normal nerve conduction studies despite convincing symptoms of peripheral neuropathy. This type of neuropathy should be considered because it is not detected on routine NCS/EMG.
What is small fiber neuropathy?
500
A patient presents with a painful axonal sensorimotor neuropathy, abdominal pain, anemia, and cognitive changes after chronic occupational exposure. This heavy metal toxicity should be suspected.
What is lead poisoning?
500
Overingestion of this mineral can induce a copper deficiency and large fiber neuropathy by impairing intestinal copper absorption.
What is zinc?
500
This chemotherapeutic agent disrupts microtubule formation and is classically associated with a severe, dose-limiting sensorimotor axonal neuropathy.
What is Vincristine?