Neuropathology (FF)

A homeless alcoholic pt confabulates responses, has nystagmus, and cannot walk properly. What deficiency has led to these findings?

Vitamin B1 (thiamine) deficiency; this is Wernicke-Korsakoff syndrome (CAN O' beer: Confusion, Ataxia, Nystagmus, Ophthalmoplegia)

A man repetitively flails his left arm and leg when he tries to move either of them. Where is the lesion?

In the right subthalamic nucleus (Dx: hemiballismus, a gross motor hyperkinesia contralateral to the deficit)

What 2 movement disorders are classically related to dysfunction of the basal ganglia?

Parkinson disease and related parkinsonian syndromes (hypokinetic) and Huntington disease (hyperkinetic)

A man with a brain-stem stroke is in a coma. A lesion in which area is responsible?

Reticular activating system in the periaqueductal gray matter (midbrain); thought to be responsible for maintaining consciousness

A man presents with trouble writing, doing math, and distinguishing fingers. He cannot tell right from left. Where is the lesion?

Dominant parietal cortex, damaged in Gerstmann syndrome (agraphia, acalculia, finger agnosia, and left-right disorientation)

An alcoholic man is confused, ataxic, and confabulating. What can unmask this disease in the hospital?

Giving dextrose in the setting of low thiamine may precipitate Wernicke-Korsakoff syndrome

An alcoholic man is confused, ataxic, and confabulating. What area of his brain is damaged?

The mammillary bodies (Wernicke-Korsakoff syndrome)

MRI of a pt with HSV-1 encephalitis shows bilateral lesions of the amygdala. What is the main symptom he might exhibit?

Disinhibited behavior such as hyperorality, hypersexuality, and hyperphagia (Klüver-Bucy syndrome)

A right-handed pt presents with makeup half done & a shoe on only her right foot. She can draw only half a clock. Where is her brain lesion?

Probably in her right (nondominant) parietal lobe; the pt is exhibiting signs of hemispatial neglect syndrome

A pt presents with a stroke affecting the area of the reticular activating system. What symptom would be expected?

Coma (levels of arousal and wakefulness severely reduced)

A pt presents with chorea and athetosis. In what region of the brain is the lesion?

Basal ganglia, which are responsible for control of voluntary movement; lesions in certain areas can also cause tremor

A pt presents with left-sided intentional tremor and limb ataxia. Where is the brain lesion likely to be found?

The left cerebellar hemisphere (cerebellar hemispheres are laterally located and affect lateral limbs)

A man has a tumor in the right cerebellar hemisphere. If it causes Sx, on which side of his body will deficits occur?

Right side (ipsilateral deficits with cerebellar lesions)

A pt has a tumor in the right cerebellar hemisphere. Which way would he fall?

Toward the right

A man walks with a wide-based gait, and his speech is slurred and difficult to understand. What part of his brain is damaged?

Cerebellar vermis (vermis is centrally located and affects the central body); damage to vermis causes truncal ataxia, dysarthria

A woman has a long Hx of significant alcohol abuse. Which part of her cerebellum is likely damaged?

Cerebellar vermis

A pt loses the ability to make new memories. Where is the brain lesion?

Hippocampus (on both sides)

A pt loses the ability to make new memories. What is this symptom called?

Anterograde amnesia, a characteristic feature of bilateral hippocampal lesions

In seizures involving the area of frontal eye fields, the eyes are directed in which direction?

Away from the side of lesion (in destructive lesions, eyes look towards the side of lesion)

A man has a lesion of the left frontal eye fields (FEFs). Where do his eyes look in relation to the lesion?

Toward the left (FEFs coordinate contralateral gaze; if the left is damaged [destructive], the right FEF will be unopposed)

A pt has a left-sided paramedian pontine reticular formation (PPRF) lesion. In what direction will the eyes deviate?

To the right (away from the lesion); PPRFs direct ipsilateral gaze, so the pt will be unable to look to the side of the lesion

A man with cerebellar damage has difficulty pronouncing words (dysarthria). What other major finding will he have on exam?

Truncal ataxia (he likely has damage to the cerebellar vermis)

What are the clinical features of Wernicke-Korsakoff syndrome?

Confusion, Ataxia, Nystagmus, Ophthalmoplegia, memory loss, confabulation, personality changes (Wernicke problems come in a CAN O' beer)

Where is the lesion in Wernicke-Korsakoff syndrome?

Mammillary bodies

A shy man is suddenly hyperoral, hypersexual, and uninhibited. CSF PCR for HSV-1 is positive. What brain lesion is to blame?

Bilateral amygdala lesions; the pt has Klüver-Bucy syndrome, associated with HSV-1 (temporal lobe) encephalitis

A pt with new frontal headaches, hostility, and poor decision making and concentration has bilateral Babinski signs. Where is the lesion?

The frontal lobe, which governs executive function and inhibits primitive reflexes

What are the features of Parinaud syndrome?

Pupillary light-near dissociation, lid retraction, vertical gaze palsy, convergence-retraction nystagmus.

A pt presents with an inability to look up at the ceiling with both eyes. What brain region is likely damaged?

Dorsal midbrain; the pt has Parinaud syndrome

A pt presents with an inability to look up at the ceiling with both eyes. What 3 underlying conditions could cause this presentation?

Stroke, hydrocephalus, or pinealoma (lesions affecting the superior colliculus); rostral interstitial nucleus also commonly involved

A pt with Hx of multiple sclerosis has left-sided nystagmus & right-sided failure of eye adduction on looking left. Where is the lesion?

Right medial longitudinal fasciculus, which coordinates the actions of the right medial and left lateral rectus muscles

A pt has a lesion of the red nucleus. What are the 2 possible posturing problems he might have? Which has worse prognosis?

Decorticate (flexor) and decerebrate (extensor) posturing; worse prognosis with decerebrate posturing

Where is the lesion in a pt with decorticate posturing? How does it present?

Above the red nucleus; presents with flexion of upper extremities and extension of lower extremities

Where is the lesion in a pt with decerebrate posturing? How does it present?

At or below the red nucleus; presents with extension of both upper and lower extremities (worse prognosis than decorticate posturing)

A pt has a long Hx of alcohol abuse. What cerebellar symptoms would be expected?

Truncal ataxia and dysarthria caused by degeneration of the cerebellar vermis

A woman dies as a result of an acute ischemic stroke. What kind of necrosis would be found in her brain at autopsy?

Liquefactive necrosis due to the action of autodigestive enzymes that disrupt the normal cellular architecture

What are the 3 most common types of ischemic stroke?

Embolic, thrombotic, and hypoxic

A pathologist determines that a pt died 12–24 hours after an ischemic stroke. What did histologic exam of the brain reveal?

Red neurons (with eosinophilic cytosol and shrunken, pyknotic nuclei); these appear 12–24 hours after ischemic insult

A pt develops pulseless electrical activity (PEA). Within how many minutes into PEA is he likely to develop irreversible brain damage?

Within 5 minutes; with no cardiac output, he has diffuse cerebral hypoxia

What 4 regions of the brain are most vulnerable to ischemic injury?

The hippocampus, cerebellum (Purkinje cells), neocortex, and watershed areas

What histologic changes are likely present in the lesion of a pt who had ischemic stroke 2 days ago?

Liquefactive necrosis and a neutrophilic infiltrate are most likely to be seen 24–72 hours after an ischemic event

If the brain tissue of a pt who had an ischemic stroke 4 days ago was viewed under a microscope, what changes would be seen?

An infiltrate of macrophages (microglia) is most often seen 3–5 days after an ischemic injury

On autopsy of a pt who had an ischemic stroke, a large glial scar is found. How long after the stroke did the scar appear?

2 weeks (a glial scar follows the histologic findings of reactive gliosis and vascular proliferation in weeks 1-2)

A pt has acute-onset left-sided hemiplegia that began ∼2 hours ago. Findings on head CT are unremarkable. What kind of stroke is this?

Ischemic stroke is most likely, as CT is sensitive primarily for blood in the setting of an acute stroke

A pt has had acute dysarthria, ataxia, and vertigo for 30 minutes. What type of imaging would detect an ischemic stroke at this time?

Diffusion-weighted MRI can detect ischemia within 3–30 min of onset; however, CT would be indicated first to rule out hemorrhage

A pt presents with acute-onset hemiplegia. Which type of brain imaging is indicated at this time?

Noncontrast CT is indicated to rule out hemorrhage, which would contraindicate use of tissue plasminogen activator

A man has hemiplegia that began 10 hours ago. Will the stroke be visible on CT or MRI?

It will likely be visible on both CT and MRI; MRI detects ischemia within 3–30 minutes, and CT shows ischemia within 6–24 hours

What 3 predisposing risk factors commonly contribute to embolic stroke?

Atrial fibrillation, carotid artery stenosis, and DVT with patent foramen ovale

A pt with atrial fibrillation has a stroke affecting multiple vascular territories. What is the likely etiology of the stroke?

An embolism from the heart traveled up the cerebral vessels and fragmented into smaller emboli (to affect multiple territories)

A man develops an acute right facial palsy. Function returns 10 minutes later while he is waiting in the ED. Dx?

Transient ischemic attack (TIA), a brief, reversible period of neurologic dysfunction from focal ischemia without MRI findings

An elderly man with no hemorrhage risk comes to the ED after 2 hours of hemiparesis. Results of head CT are completely normal. Tx?

Tissue plasminogen activator (tPA); if a stroke occurred in the past 3–4.5 hours, tPA can be given to a pt with no contraindications

An elderly pt with recent ischemic stroke comes in for follow-up. What are 3 methods of decreasing his future stroke risk?

Antiplatelet therapy (aspirin); manage comorbidities (atrial fibrillation, carotid stenosis); control of BP, blood glucose and lipid levels

A pt develops hypotension while undergoing cardiac surgery. For what type of stroke is he at risk?

Hypoxic stroke caused by hypoperfusion or hypoxemia; it is common in cardiovascular surgeries and tends to affect watershed areas

A pt with Hx of DVTs has a new ischemic stroke. Why do you decide to perform an echocardiogram with bubble study?

Given the DVT Hx, you want to rule out a patent foramen ovale or ASD (through which paradoxical emboli may reach the brain)

A pt with Hx of stable angina and a carotid bruit has an MCA stroke. What type of ischemic stroke is this?

Thrombotic (carotid bruit suggests stenosis, likely secondary to atherosclerotic disease in a pt with risk factors)

A pt with Hx of stable angina and a carotid bruit has an MCA stroke. What is the likely mechanism?

Atherosclerotic plaque rupture, the most common cause of thrombotic stroke

A diabetic smoker has an MCA infarction (image). Embolic disease is ruled out. What is the most likely etiology?

Formation of a clot over an atherosclerotic plaque

A pt presents with evidence of a large stroke (image). What artery is likely occluded by a thrombus?

Right MCA

Where does the hemorrhage in neonatal intraventricular hemorrhage originate?

Germinal matrix (highly vascularized zone within subventricular zone)

Why are premature infants more at risk of intraventricular hemorrhage?

Reduced glial fiber support and impaired BP autoregulation

What are the symptoms of neonatal intraventricular hemorrhage?

Bulging fontanelle, altered level of consciousness, hypotension, seizures, coma

A premature, low birth weight infant presents with hypotension, seizure and bulging fontanelle. MRI is shown (image). Dx?

Neonatal intraventricular hemorrhage (arrow indicates blood in right ventricle, extending into periventricular white matter)

A man has an intraparenchymal hemorrhage. Which blood vessel abnormality likely predisposed this pt to this stroke?

His lenticulostriate vessels likely had Charcot-Bouchard aneurysms from long-standing hypertension

A pt, hospitalized after a subarachnoid bleed, has a new-onset ischemic stroke 3 days later. What medication could have prevented this?

Nimodipine, which is given to prevent vasospasm after a subarachnoid hemorrhage

A baby is shaken by a frustrated mother. What type of hematoma would you expect to see on head CT?

A subdural hematoma, which is produced by the shearing of sensitive bridging veins within the immature skull

An elderly pt with Alzheimer disease has 2 cortical intraparenchymal hemorrhages in different lobes. What is the likely underlying cause?

Amyloid angiopathy, which leads to recurrent lobar hemorrhagic strokes in the elderly, often those with preexisting amyloidopathy

What kind of intracranial hematoma crosses suture lines but not the falx? What kind crosses the falx but not suture lines?

A subdural hematoma crosses suture lines; an epidural hematoma crosses the falx

A pt from a nursing home presents with altered mental status after several falls. Likely cause of altered mental status?

Subdural hematoma (or several) as a result of physical trauma from the falls

A pt is hospitalized after a subarachnoid bleed. What may occur in the first 3–10 days after hemorrhage?

Vasospasm, which can impair blood flow and lead to further morbidity

A pt is hospitalized after a subarachnoid bleed. For what 2 kinds of hydrocephalus is the pt at risk?

Obstructive hydrocephalus, if blood clogs a foramen or aqueduct; communicating hydrocephalus, if arachnoid granulations are blocked

"A woman presents with the ""worst headache of her life."" Spinal tap shows xanthochromia. Dx?"

Subarachnoid hemorrhage

"A pt presents with the "" worst headache of her life."" Spinal tap shows xanthochromia. What 2 vascular anomalies can produce this condition?"

Saccular aneurysm and arteriovenous malformation (less common); rupture of either produces a subarachnoid hemorrhage

A pt is struck on the side of the head by a baseball bat. He appears fine initially but becomes obtunded 30 minutes later. Dx?

Likely an epidural hematoma with skull fracture at the pterion (the pt had a classic lucid interval followed by hematoma expansion)

A pt is rushed to the hospital, and an expanding epidural hematoma is identified on head CT. What are 2 complications of hematoma expansion?

"Transtentorial herniation (ie, central or uncal herniation) and CN III palsy (with ""down and out"" eye, mydriasis, etc)"

A pt with a Hx of multiple falls has a subdural hematoma identified on head CT. What are 2 key predisposing factors?

"Cerebral atrophy, which causes retraction of the parenchyma and ""stretches"" bridging veins, and trauma (eg, falls)"

A pt presents with a sudden-onset severe headache. CT shows blood in the prepontine cisterns. What would lumbar puncture reveal?

Xanthochromia, a yellowish discoloration of the CSF due to the breakdown of heme to bilirubin

What are the most common sites for intraparenchymal hemorrhage?

Putamen of basal ganglia (lenticulostriate vessels), thalamus, pons and cerebellum

A man is hit on the head by a wrench. He has a pterion skull fracture, but says he feels fine. Despite this, why do you monitor him closely?

His skull fracture predisposes him to middle meningeal artery rupture, which could lead to an epidural hematoma

In a patient who develops an epidural hematoma, what bony region is likely fractured in the skull and why?

The pterion, which is the thinnest area of the lateral skull

A man is hit on the head with a pipe. Axial CT is shown in the image. Could this be fatal?

Yes (this is an epidural hematoma); may result in transtentorial hernia and CN III palsy

An elderly man fell and hit his head. CT scan is shown (image). What predisposed him to develop this hematoma?

Age; chronic subdural hematomas are seen more often in the elderly; other risk factors are brain atrophy, mild trauma, alcoholism

An elderly woman fell and hit her head on the opposite side of a prior injury. CT scan is shown. Which hematoma is new and which is old?

Hyperdense regions are acute bleeds, and hypodense regions are chronic bleeds (Dx: acute-on-chronic subdural hematoma)

A man develops the worst headache of his life. CT scan is shown (image). What could have caused this?

A ruptured aneurysm or arteriovenous malformation; note the blood in the cisterns, indicating a subarachnoid hemorrhage

A man develops the worst headache of his life. CT scan is shown (image). What will CSF analysis show?

Bloody or xanthochromic CSF (this is a subarachnoid hemorrhage)

This CT image shows an infarction of the basal ganglia and internal capsule. What conditions are associated with this type of stroke?

Systemic hypertension, amyloid angiopathy, vasculitis, and neoplasms (this is an intraparenchymal hemorrhage)

A man had a left-sided ischemic cerebellar stroke. A week later, he suddenly develops a severe headache. CT scan is shown. What happened?

Reperfusion injury (hemorrhagic conversion) of his stroke

Noncontrast CT in a pt who had a stroke shows bright areas in the basal ganglia (image). What factors predispose for this type of stroke?

Cancer, HTN, anticoagulation, reperfusion injury after ischemic stroke (this is a hemorrhagic stroke/intracerebral bleeding)

A pt with Marfan syndrome has xanthochromic CSF and the imaging findings shown. Dx?

Subarachnoid hemorrhage, likely caused by the rupture of a saccular aneurysm

A baseball hits a man on the head. He seems fine initially, but his condition deteriorates rapidly. Axial CT is shown. What artery ruptured?

The middle meningeal artery, a maxillary artery branch (this is an epidural hematoma)

An elderly woman falls and hits her head. CT scan is shown (image). Rupture of what blood vessel led to this kind of hematoma?

Ruptured bridging veins and slow bleeding caused a subdural hematoma (note the crescent shape [red arrow] and midline shift [yellow arrow])

A woman fell from a 4th-floor window. CT is shown (image). Dx?

Epidural hematoma

A pt presents with the CT findings shown (image). Dx?

Subarachnoid hemorrhage with enhancement of the basal cisterns

A pt presents with the CT findings shown (image). How does this type of injury occur?

Epidural hematoma (with lentiform hemorrhage) occurs as a result of rupture of the middle meningeal artery (especially at the pterion)

A pt presents with the CT findings shown (image). Dx?

Intraparenchymal (intracerebral) hemorrhage

A pt presents with the CT findings shown (image). What is the most likely underlying cause of this condition?

Systemic HTN (Findings indicate intraparenchymal [intracerebral], or hypertensive, hemorrhage)

A pt receives thrombolytic therapy for an ischemic cerebellar stroke but soon after develops the CT findings shown. What is the mechanism?

Reperfusion injury secondary to tPA administration; hemorrhage into the weakened ischemic area is a key risk of thrombolytic therapy

What are the brain regions affected in anterior inferior cerebellar artery (AICA) stroke?

Lateral pons (also middle and inferior cerebellar peduncles, labyrinthine artery)

What brain region is affected in posterior inferior cerebellar artery (PICA) stroke?

Lateral medulla

A pt loses sensation and strength in his left arm and face. He seems to neglect the left side as well. Where is the stroke located?

The right middle cerebral artery (MCA) distribution; damage to the nondominant (usually right) parietal lobe causes hemineglect

A pt suddenly loses the right visual field of each eye but retains some of the center field. What artery was affected?

Left posterior cerebral artery, causing damage to occipital and visual cortex with macular sparing; also causes alexia w/o agraphia