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190 Cards in this Set
- Front
- Back
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Basics: Nissl Substance
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Stairs RER within cell bodies and dendrites, but not axons.
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Basics: Microglia
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Mesodermally-derived CNS macrophages.
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Basics: Meissner's Corpuscles
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Group Aβ fibers; rapidly-adapting proprioception and dynamic fine touch; within glabrous skin.
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Basics: Pacinian Corpuscles
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Group Aβ fibers; rapidly-adapting vibration and pressure; within deep skin, ligaments, and joints.
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Basics: Merkel Disks
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Group Aβ fibers; slowly-adapting proprioception and static touch; within hair follicles.
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CNS Pathology: Norepinephrine
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High in anxiety, low in depression.
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CNS Pathology: Dopamine
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High in schizophrenia, low in Parkinson's, low in depression.
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CNS Pathology: 5-HT
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Low in anxiety, low in depression.
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CNS Pathology: ACh
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Low in Alzheimer's, low in Huntington's, low in REM sleep.
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CNS Pathology: GABA
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Low in anxiety, low in Huntington's.
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Function: Anterior Hypothalamus.
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Senses elevated body temperature ---> parasympathetic output for body cooling.
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Function: Posterior Hypothalamus.
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Senses decreased body temperature ---> sympathetic output for body heating.
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Function: Lateral Hypothalamus.
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"Hunger center." Lesion ---> anorexia. Inhibited by leptin.
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Function: Ventromedial Hypothalamus.
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"Satiety center." Lesion ---> hyperphagia/obesity. Stimulated by leptin.
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Product: Supraoptic Nucleus of the Hypothalamus.
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ADH and Oxytocin.
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Product: Paraventricular Nucleus of the Hypothalamus.
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ADH and Oxytocin.
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Function: Septal Nucleus.
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Pleasure/Gratification/Sexual urges.
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Connections: Ventral Posterior Lateral Nucleus of the Thalamus.
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Dorsal columns, anterolateral tracts, primary somatosensory cortex.
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Connections: Ventral Posterior Medial Nucleus of the Thalamus.
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Sensory nucleus of V, spinal nucleus of V, primary somatosensory cortex.
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Connections: Ventral Anterior, Ventral Lateral Nuclei of the Thalamus.
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Basal ganglia, primary motor cortex.
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Direct Basal Ganglia Pathway.
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Excitatory to cortex:
Striatum to GPi/SNpr (GABA); GPi/SNpr to VA/VL thalamus (GABA). |
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Indirect Basal Ganglia Pathway.
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Inhibitory to cortex.
Striatum to GPe (GABA); GPe to STN (GABA); STN to GPi/SNpr (Glu); GPi/SNpr to VA/VL thalamus (GABA) |
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Nigrostriatal Pathway.
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Substantia nigra pars compacta to striatum.
D1: excitatory to direct pathway (net excitation) D2: inhibitory to indirect pathway (net excitation) |
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Classic symptoms: Parkinson's.
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TRAPG:
Tremor Rigidity Akinesia (Bradykinesia) Postural instability Gait instability |
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Basics: Hemiballismus.
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Sudden, wild flailing of 1 arm +/− leg. Associated with damage to contralateral STN.
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Classic symptoms: Huntington's.
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Chorea, athetosis; depression; progressive dementia.
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Imaging: Huntington's.
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Severely atrophied caudate, enlarged ventricles, defined sulci.
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Basics: Huntington's.
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Autosomal dominant CAG repeated disorder. Chromosome 4.
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Define: Chorea.
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Sudden, jerky, purposeless movements. Characteristic of basal ganglia lesion (e.g. Huntington’s disease).
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Define: Athetosis.
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Slow, writhing movements, especially of fingers. Characteristic of basal ganglia lesion (e.g. Huntington’s disease).
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Basics: Dystonia.
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Sustained, involuntary muscle contractions.
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Basics: Essential Tremor.
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AKA "postural tremor."
Action tremor (worsens when holding posture), autosomal dominant. Essential tremor patients often self-medicate with alcohol, which ↓ tremor. |
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Treatment: Essential Tremor.
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Treatment: β-blockers.
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Basics: Resting Tremor.
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Abates with purposeful movement, most noticeable distally. Seen in Parkinson’s.
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Basics: Intention Tremor.
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Slow, zigzag motion when pointing toward a target; associated with
cerebellar dysfunction. |
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Function: Dorsolateral Prefrontal Cortex.
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Working memory.
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Function: Orbitofrontal Cortex.
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Social and emotional decision-making.
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Function: Anterior Cingulate Cortex.
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Motivation.
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Motor/Sensory Homunculus
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Legs and feet medially; arms, hands, face laterally.
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Basics: Klüver-Bucy Syndrome.
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Results from bilateral amygdala lesion.
Hyperorality, hypersexuality, and disinhibited behavior. |
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Lesion: Mammillary Bodies (Bilateral) .
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Wernicke-Korsakoff syndrome
Wernicke's: ataxia, confusion, ophthalmopegia. Korsakoff's: amnesia, confabulation. |
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Lesion: PPRF.
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Eyes deviate AWAY from the side of the lesion.
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Lesion: Frontal Eye Fields.
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Eyes deviate TOWARD the side of the lesion.
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Lesion: Hippocampus.
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Anterograde amnesia.
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Lesion: Cerebellar Vermis.
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Truncal ataxia and dysarthria.
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Lesion: Cerebellar Hemisphere.
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Intention tremor, limb ataxia.
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Lesion: Right Parietal Lobe.
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Contralateral hemineglect.
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Basics: Central Pontine Myelinolysis.
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Demyelinating disorder ssociated with rapid correction of hyponatremia. Acute paralysis, dysarthria, dysphagia, diplopia, and loss of consciousness. Recovery rare.
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Lesion: Recurrent Laryngeal Nerve.
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Loss of all laryngeal muscles except cricothyroid. Hoarseness
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Basics: Broca's Aphasia.
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Non-fluent with intact comprehension.
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Basics: Wernicke’s Aphasia.
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Fluent aphasia with impaired comprehension.
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Basics: Global Aphasia.
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Nonfluent aphasia with impaired comprehension (Broca's + Wernicke's).
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Basics: Conduction Aphasia.
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Poor repetition but fluent speech, intact
comprehension. Arcuate fasciculus lesion—connects Broca’s, Wernicke’s areas. |
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Basics: Berry Aneurysm.
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Occur at the bifurcations in the circle of Willis. Most common site is bifurcation of the anterior communicating artery. Rupture (most common complication) leads to hemorrhagic stroke/subarachnoid hemorrhage.
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Basics: Charcot-Bouchard Microaneurysms.
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Associated with chronic hypertension; affects
small vessels (e.g., in basal ganglia, thalamus). |
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Basics: Epidural Hematoma.
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Rupture of middle meningeal artery (branch of maxillary artery), often 2° to fracture of temporal bone. Lucid interval. Rapid expansion under systemic arterial pressure →
transtentorial herniation, CN III palsy. “Biconvex disk” on CT. |
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Basics: Subdural Hematoma.
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Rupture of bridging veins. Slow venous bleeding with delayed onset of symptoms. Seen in elderly individuals, alcoholics, blunt trauma, shaken babies.
Crescent-shaped hemorrhage on CT. |
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Basics: Subarachnoid Hemorrhage.
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Rupture of an aneurysm or an AVM. Patients complain of “worst headache of my life.”
Bloody or yellow spinal tap. 2–3 days afterward, there is a risk of vasospasm due to blood breakdown products, which irritate vessels (treat with calcium channel blockers). |
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Basics: Transient Ischemic Attack (TIA).
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Brief, reversible episode of neurologic dysfunction due
to focal ischemia. Typically, symptoms last for < 24 hours. |
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Basics: Stroke Imaging.
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Bright on diffusion-weighted MRI in 3–30 minutes and remains bright for 10 days, dark on CT in ~ 24 hours.
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Basics: Normal Pressure Hydrocephalus.
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Does not result in ↑ subarachnoid space volume. Expansion of ventricles distorts the fibers of the corona radiata and leads to the clinical triad of
dementia, ataxia, and urinary incontinence. |
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Basics: Communicating Hydrocephalus.
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↓ CSF absorption by arachnoid villi, which can lead to ↑ intracranial pressure, papilledema, and herniation
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Basics: Obstructive Hydrocephalus.
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Caused by a structural blockage of CSF circulation within the ventricular system.
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"Hydrocephalus ex vacuo"
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Appearance of ↑ CSF in atrophy (e.g., Alzheimer’s disease, advanced HIV). Intracranial pressure is normal; triad is not seen.
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Common location: Vertebral Disc Herniation.
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Between L5 and S1.
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Modalities: Dorsal Columns.
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Fine touch, conscious proprioception, two-point discrimination, stereognosis.
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Modalities: Anterolateral (Spinothalamic) Tract.
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Pain and temperature.
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Sx: LMN Syndrome.
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Flaccid paralysis, hyporeflexia, atrophy, fibrillations, fasciculations.
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Sx: UMN Syndrome.
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Rigid paralysis, hyperreflexia, spasticity, Babinski sign
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Sx: Horner's syndrome.
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Ptosis, miosis, anhidrosis.
Associated with lesion of spinal cord above T1. |
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Spinal Level: Biceps Reflex.
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C5, C6 nerve roots.
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Spinal Level: Triceps Reflex.
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C7, C8 nerve roots.
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Spinal Level: Patellar Reflex.
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L3, L4 nerve roots.
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Spinal Level: Achilles Reflex.
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S1, S2 nerve roots.
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Functions: Solitary Nucleus.
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"Nucleus of Sensation and Taste" = IX, X, and VII
Taste from VII, IX, X Visceral sensory from IX, X |
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Function: Nucleus Ambiguus.
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Motor nucleus of 9, 10.
Preganglionic parasympathetics of X to the heart. |
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Function: Dorsal Motor Nucleus of X.
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Preganglionic parasympathetics of X to lungs, gut.
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CN XII Lesion.
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Tongue deviates toward side of lesion
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CN V Motor Lesion.
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Jaw deviates toward side of lesion. Bilateral cortical input to lateral pterygoid muscle.
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CN X Lesion.
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Uvula deviates away from side of lesion. Weak side collapses and uvula points away.
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CN XI Lesion.
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Weakness turning head to contralateral side of lesion (SCM). Ipsilateral shoulder
droop (trapezius). |
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Cortical Facial Palsy.
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Contralateral facial paralysis only in lower quadrant.
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Peripheral Facial Palsy.
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Ipsilateral paralysis of upper and lower face.
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Basics: Wallenberg Syndrome.
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Sx: ipsilateral loss of face pain/temp; contralateral loss of body pain/temp; ipsilateral Horner's syndrome; nausea/vertigo/nystagmus; dysarthria/dysphagia
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Vessel: Wallenberg Syndrome.
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Vertebral artery or PICA
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Basics: Weber Syndrome.
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Ipsilateral oculomotor palsy and contralateral body paresis
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Vessels: Weber Syndrome.
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PCA or basilar artery
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Components: Limbic System.
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Cingulate, hippocampus, amgydala, fornix, mammillary bodies.
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Cerebellar Nuclei and Associated Regions.
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Lateral to medial:
Dentate (lateral); interposed (intermediate); fastigial (vermis) Interposed = emboliform and globose. |
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Cerebellum: "Climbing" vs. "Mossy" Fibers.
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Climbing fibers: from contralateral inferior olivary nucleus to Purkinje cells.
Mossy fibers: All other inputs (dorsal spinocerebellar, vestibular, pontine, etc) to granule cells. |
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Basics: OVLT
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"Organum vasculosum of the lamina terminalis"
Circumventricular organ sensitive to body tonicity; output to neurohypophysis for regulation of ADH secretion. |
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Basics: SFO
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"Sub-fornical organ"
Circumventricular ogran sensitive to [AT2]; output to hypothalamus for regulation of thirst (and ADH output). |
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Lesion: Cerebral Hemisphere.
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Intention tremor, limb ataxia; damage to the cerebellum results in ipsilateral deficits
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Lesion: Mammillary Bodies.
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Wernicke-Korsakoff syndrome.
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Lesion: Anterior Spinal Artery.
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Contralateral hemiparesis (lower extremities), medial lemniscus (↓ contralateral proprioception), ipsilateral paralysis of hypoglossal nerve
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Lesion: PICA
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Wallenberg syndrome
Contralateral body pain/temp, ipsilateral face pain/temp, vestibular nucleus lesion (vertigo/nystagmus/diplopia), ipsilateral Horner's (RVLT lesion), dysphagia, dysarthria |
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Lesion: AICA
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Ipsilateral facial palsy, ipsilateral deafness, loss of ipsilateral pain/temp, ipsilateral limbgait ataxia
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Lesion: Posterior Cerebral Artery
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Contralateral homonymous hemianopia with macular sparing (supplies occipital cortex)
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Lesion: Middle Cerebral Artery
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Contralateral face and arm paralysis and sensory loss, aphasia (dominant sphere),
left-sided neglect. |
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Lesion: Anterior Cerebral Artery.
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Motor and sensory deficits to contralateral leg and trunk.
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Infarct: Basilar Artery
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"Locked-in" syndrome.
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General Outcome: Anterior Circulation Stroke
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General sensory and motor dysfunction, aphasia.
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General Outcome: Posterior Circulation Stroke
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Cranial nerve deficits (vertigo, visual deficits), coma, cerebellar deficits (ataxia).
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Basics: Area Postrema
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Circumventricular organ within 4th ventricular; chemoreceptor trigger zone for nausea/vomiting reflex; only bilateral CVO
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# of Spinal Nerves
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31 Total
8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal |
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Pathway: Dorsal Columns.
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Peripheral receptor ---> medial DREZ ---> ipsilateral fasciculus gracilis/cuneatus ---> nucleus gracilis/cuneatus (synapse) ---> decussate as internal arcuate fibers ---> ascend as medial lemniscus ---> ventral posterior lateral thalamus (synapse) ---> primary somatosensory cortex (synapse)
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Pathway: Anterolateral (Spinothalamic) Tract.
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Peripheral fibers ---> lateral DREZ ---> ipsilateral anterolateral spinal funiculus (synapse) ---> decussate within 2 spinal levels ---> ascend to ventral posterior lateral thalamus (synapse) ---> primary somatosensory cortex
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Pathway: Dorsal Spinocerebellar Tract.
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Peripheral receptor ---> medial DREZ ---> Column of Clarke nuclei ---> ipsilateral dorsolateral funiculus ---> ipsilateral cerebellum (via ICP)
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Pathway: Corticospinal tract.
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Primary motor cortex ---> corona radiata ---> internal capsule (posterior limb) ---> cerebral peduncles ---> decussation in medullary pyramids ---> lateral and anterior spinal funiculi ---> synapse on α and γ motor neurons.
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Lesion: Horner's syndrome.
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Spinal lesion above T1.
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Sensory/Motor/Both: CN I
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Sensory
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Sensory/Motor/Both: CN II
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Sensory
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Sensory/Motor/Both: CN III
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Motor
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Sensory/Motor/Both: CN IV
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Motor
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Sensory/Motor/Both: CN V
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Both
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Sensory/Motor/Both: CN VI
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Motor
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Sensory/Motor/Both: CN VII
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Both
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Sensory/Motor/Both: CN VIII
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Sensory
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Sensory/Motor/Both: CN IX
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Both
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Sensory/Motor/Both: CN X
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Both
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Sensory/Motor/Both: CN XI
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Motor
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Sensory/Motor/Both: CN XII
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Motor
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Cranial Nerve Nuclei: Midbrain
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III, IV
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Cranial Nerve Nuclei: Pons
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V, VI, VII, VIII
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Cranial Nerve Nuclei: Medulla
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IX, X, XI, XII
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Afferent/Efferent: Corneal Reflex
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Afferent: V1
Efferent: VII |
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Afferent/Efferent: Lacrimal Reflex
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Afferent: V1
Efferent: VII |
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Afferent/Efferent: Jaw Jerk Reflex
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Afferent: V3
Efferent: V3 |
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Afferent/Efferent: Pupillary Reflex
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Afferent: II
Efferent: III |
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Afferent/Efferent: Gag Reflex
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Afferent: IX
Efferent: IX, X |
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Cranial Foramen: CN I
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Cribiform plate of the ethmoid bone.
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Cranial Foramen: CN II
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Optic canal.
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Cranial Foramen: CN III
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Superior orbital fissure.
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Cranial Foramen: CN IV
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Superior orbital fissure.
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Cranial Foramen: CN V1
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Superior orbital fissure.
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Cranial Foramen: CN VI
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Superior orbital fissure.
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Cranial Foramen: CN V2
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Foramen rotundum.
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Cranial Foramen: CN V3
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Foramen ovale.
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Cranial Foramen: CN VIII
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Internal acoustic meatus.
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Cranial Foramen: CN VIII
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Internal acoustic meatus.
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Cranial Foramen: CN IX
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Jugular foramen.
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Cranial Foramen: CN X
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Jugular foramen.
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Cranial Foramen: CN XI
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Jugular foramen.
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Cranial Foramen: CN XII
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Hypoglossal canal.
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Nerves that Pass Through the Cavernous Sinus
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CN III, IV, V1, V2, VI
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Sx: Cavernous Sinus Syndrome
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Ophthalmoplegia and sensory loss within the distribution of V1 and V2 (ophthalmic and maxillary)
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Functions: Muscles of Mastication
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Jaw opening: Lateral pterygoid
Jaw closing: Medial pterygoid, masseter, temporalis |
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Function: Otolith Organs
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Linear acceleration and gravity.
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Function: Semicircular Canals.
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Angular acceleration.
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Mechanism: Semicircular Canals.
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Endolymph displaces hair cell stereocilia enclosed within cupulas, contained within ampulas at the base of the canals.
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Mechanism: Otolith Organs.
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Endolymph displaces hair cell stereocilia embedded within calcium carbonate matrix.
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Structure/Tonotopy of Basilar Membrane.
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Base: Narrow, elastic; sensitive to high frequencies.
Apex: Wide, compliant; sensitive to low frequencies. |
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Function: Outer Cochlear Hair Cells.
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Modulate sensitivity of basilar membrane to different frequencies.
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Pathway: Sound ---> Hair Cells.
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Tympanic membrane ---> malleus ---> incus ---> stapes ---> oval window ---> basilar membrane/tectorial membrane ---> hair cells.
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Composition: Endolymph.
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Very high [K+]
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Composition: Perilymph
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Very high [Na+]
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Ocular Tunics and Components
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Fibrous: Sclera, cornea
Vascular: Choroid, iris, ciliary body Neural: Retina |
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Pathway: Aqueous Humor
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Secreted in posterior chamber by ciliary bodies ---> passes between iris and lens into anterior chamber ---> drained by canal of Schlemm into ophthalmic veins
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Basics: Glaucoma.
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Impaired flow of aqueous humor →↑intraocular pressure → optic disk atrophy with cupping.
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Wide-Angle Glaucoma.
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Obstructed outflow through canal of Schlemm; much more common; painless/"silent"
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Closed-Angle Glaucoma
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Obstruction of flow between iris and cornea → pressure buildup
behind iris. Very painful, ↓ vision, rock-hard eye, frontal headache. Do not give epinephrine! |
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Presentation: CN III damage
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damage—eye looks down and out; ptosis, pupillary dilation, loss of accommodation.
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Presentation: CN IV Palsy.
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Diplopia with a defective
downward gaze (patients adjust by tilting head toward side of the lesion). |
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Presentation: CN VI Palsy.
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Medially directed eyes.
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Presentation: Unilateral MLF Lesion
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"Internuclear ophthalmoplegia": Ipsilateral medial rectus palsy on attempted lateral gaze with contralateral nystagmus.
Convergence intact! |
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Findings: Caloric Test
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Cold water: Ipsilateral deviation
Warm water: Contralateral deviation. |
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Charcot's Triad (Multiple Sclerosis)
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Dysarthria, intention tremor, and nystagmus.
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Classic findings: MS
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Charcot's triad (dysarthria, intention tremor, nystagmus), unilateral optic neuritis, hemiparesis,
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Course: MS
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Relapsing and remitting inflammation and neurodegeneration.
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Epidemiology: MS
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Most commonly: white women in their 20s and 30s
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Lab Findings: MS
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Oligoclonal bands; MRI with periventricular plaques.
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Treatment: MS
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β-interferon, mitoxantrone, natalizumab.
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Toxicity: Opioids
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Respiratory depression, nausea/vomiting, constipation, miosis, pruritis
Additive CNS depression with other drugs. |
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Antidote: Opioid Overdose
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Naltrexone.
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Mechanism: Tramadol
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Very weak opioid agonist; also inhibits serotonin and NE reuptake
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Use: Tramadol
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Chronic pain
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Toxicity: Tramadol
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Respiratory depression, nausea/vomiting, constipation, miosis, pruritis
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Opioid Receptor Signaling
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K+ channel activation, Ca2+ inactivation ---> hyperpolarization, inhibited transmitter release
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Mechanism: Phenytoin
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↑ Na+ channel inactivation
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Mechanism: Carbamazepine
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↑ Na+ channel
inactivation |
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Mechanism: Lamotrigine
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Blocks voltage-gated
Na+ channels |
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Mechanism: Gabapentin
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Primarily inhibits Ca2+ channels
GABA analogue with NO GABA receptor activity |
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Mechanism: Topiramte
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Blocks Na+ channels, ↑ GABA action
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Mechanism: Phenobartbital
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Facilitate GABA-A action by ↑ duration of Cl− channels
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Mechanism: Valproate
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↑ Na+ channel inactivation, ↑ GABA concentration
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Mechanism: Ethosuximide
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Blocks thalamic T-type Ca2+ channels
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Clinical Use: Phenytoin
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Tonic-clonic seizures.
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Clinical Use: Phenobarbital
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Anxiety, seizures, insomnia
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Clinical Use: Benzodiazepines
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Anxiety, spasticity, status epilepticus
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Tx: Benzodiazepine Overdose
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Flumazenil, competitive GABA antagonist
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