Neuro Basics
These fibers bring sensory information from the periphery into the CNS
What are afferent fibers?
This temporary state after SCI features loss of all function below the injury, negative rectal tone, and low BP/HR.
What is spinal shock?
In myasthenia gravis, antibodies target these receptors at the neuromuscular junction.
What are acetylcholine receptors?
Identify the cardinal triad of Parkinson’s disease.
What is tremor, rigidity, and bradykinesia?
MS is characterized by damage to this structure on CNS neurons.
What is the myelin sheath?
ALS damages which two motor neuron pathways?
What are upper and lower motor neurons?
This dopaminergic combination is the mainstay for Parkinson’s; one component crosses the BBB to become dopamine, while the other prevents peripheral conversion to reduce side effects.
What is carbidopa/levodopa?
Upper motor neurons are located here, while lower motor neurons send axons out of the spinal cord to muscles.
What is the brain and spinal cord?
Secondary cord injury can occur due to ischemia from vasospasm, swelling, and release of damaging enzymes
What are vascular compromise (vasospasm), edema, and cellular mediator/enzyme release leading to secondary injury?
Weakness improving with rest and responsiveness to anticholinesterase medication suggests this diagnosis.
What is myasthenia gravis?
This medication combination increases CNS dopamine while reducing peripheral conversion.
What is carbidopa/levodopa?
MS lesions commonly develop in which part of the nervous system?
What is the CNS white matter?
Name one hallmark LMN finding in ALS.
What are fasciculations?
This anticholinergic helps normalize the acetylcholine–dopamine imbalance, reducing tremor/rigidity in parkinsonism.
What is benztropine?
Name two hallmark exam findings of upper motor neuron damage due to loss of brain modulation of spinal reflexes.
What is hyperreflexia and spasticity/increased tone?
In this incomplete SCI syndrome, arm weakness exceeds leg weakness due to central cord involvement near gray matter.
What is central cord syndrome?
Name the medication used as a diagnostic agent for MG.
What is edrophonium (Tensilon)?
Which medication class helps reduce tremors by blocking acetylcholine?
What are anticholinergics (e.g., benztropine)?
Name one classic visual symptom of MS.
What is optic neuritis?
ALS commonly begins affecting which body region?
What are the upper extremities?
Pyridostigmine treats MG by inhibiting this enzyme, increasing ACh at the neuromuscular junction—but watch for bradycardia, bronchospasm, and GI hyperactivity.
What is acetylcholinesterase inhibition?
In this motor system, most tracts cross to the contralateral side; in the other, most remain ipsilateral to modulate patterned movements. Name both.
What are the pyramidal (crossing) and extrapyramidal (mostly same side) systems?
Weeks after a high thoracic SCI, a patient develops severe headache, BP ~200/100, diaphoresis above and cool, pale skin below the lesion. Name the emergency and the common triggers you must rapidly address.
What is autonomic dysreflexia; common triggers are bladder distention, bowel impaction, or infection/other noxious stimuli?
This condition can occur with excessive dosing of pyridostigmine, producing dangerous symptoms such as muscle paralysis.
What is cholinergic crisis?
Name two possible adverse effects of dopaminergics such as levodopa.
What are hallucinations and dyskinesias?
Which MS subtype is characterized by clear relapses with periods of improvement?
What is relapsing-remitting MS (RRMS)?
Which neurotransmitter is implicated in ALS-related neuronal injury?
What is glutamate?
Name two important contraindications to anticholinergics like benztropine that relate to pressure/flow in the eye and GI/GU tracts.
What is narrow-angle glaucoma or GI/GU obstruction?
A patient has flaccid paralysis, fasciculations, and absent reflexes in a limb after peripheral nerve injury. Identify the lesion level and resulting type of paralysis.
What is a lower motor neuron lesion causing flaccid paralysis with loss of reflexes and denervation atrophy?
After spinal shock resolves, a complete injury above T12 will show these reflex and tone patterns—whereas a complete injury at/below T12 shows the opposite.
Above T12 (UMN): return of reflexes, spasticity/hypertonia; T12 or below (LMN): loss of reflex arcs, flaccid paralysis.
A patient shows respiratory distress and worsening weakness. Distinguish between MG crisis vs. cholinergic crisis.
MG crisis involves worsening weakness from insufficient ACh, whereas cholinergic crisis involves excessive ACh leading to paralysis.
A patient on levodopa develops hallucinations. What are two safe management steps?
Reduce levodopa dose; eliminate interacting agents (MAOIs/Vitamin B6).
Explain why MS patients may initially regain function after a relapse.
Due to remyelination restoring partial conduction efficiency.
Identify the most common cause of death in ALS.
What is respiratory failure?
A patient on carbidopa/levodopa develops hallucinations and involuntary movements. Identify two plausible strategies to manage this and one drug or nutrient interaction to avoid.
Reduce dose and avoid MAOIs or vitamin B6.