SCNM Neuro Exam Study Guide
@ 2024
Cerebral Edema (vasogenic, cytotoxic hydrocephalic) - Answer There are three kinds:
Brain is softer, gyri are flattened, sulci are narrowed, and ventricular cavities are
compressed
a.fluid escapes from the blood vessels into the intercellular space of the brain.
Localized (abscesses, neoplasms), or generalized
b.increase in intracellular fluid secondary to cellular injury (generalized
hypoxic/ischemic insult)
c.fluid from the intraventricular CSF flows to the periventricular white matter during
hydrocephalus
Subfalcine hernation - Answer cingulate gyrus displaces under the falx cerebri,
associated with compression of anterior cerebral artery
Transtentorial hernation- - Answer medial aspect of the temporal lobe is compressed
against the free margin of the tentorium cerebelli. Oculomotor nerve (3) is compressed
(pupillary dilation, impairment of ocular movements), posterior cerebral artery
(ischemia of primary visual cortex), hemorrhagic lesion in midbrain and pons - Duret
hemorrhages
Tonsillar herniation - Answer displacement of cerebellar tonsils through the foramen
magnum and compression of medulla oblongata (death)
Hydrocephalus - Answer Accumulation of excessive CSF within the ventricular system
of the brain d/t decreased resorption of CSF, It results in a) dilation of ventricles and
increase of intracranial pressure, b) enlargement of head, if sutures are not closed, c)
expansion of ventricles, if sutures are closed
frontal - Answer a fracture after loss of consciousness usually occurs here
occipital - Answer a fall while conscious usually occurs here fracture
Concussion - Answer alteration of consciousness secondary to head injury. Loss of
consciousness, temporary respiratory arrest, and loss of reflexes. Biochemical and
physiologic abnormalities occur (decreased ATP, depolarization of membranes)
frontal lobe, orbital gyri, temporal lobes - Answer Direct Parenchymal Injury when the
head is immobile occurs here
,coup & contrecouup injury - Answer Direct Parenchymal Injury when the head is mobile
results in these two types of damages
contrecoup - Answer denoting an injury to the brain, occurring at a site opposite to the
point of impact
Diffuse Axonal Injury - Answer Mechanic forces damage the integrity of the axon in the
Node of Ranvier with alterations in axoplasmic flow. Axonal swellings and hemorrhage
of the area. Coma shortly after trauma
Epidural Hematoma - Answer laceration of middle meningeal artery, especially in
fractures of the temporal bone. Accumulation of blood separates dura from the skull.
Clinically - pt is lucid for several hours after trauma until neurologic signs develop.
Subdural hematoma - Answer displacement of brain that occurs in trauma can tear the
veins at the point where they penetrate the dura, because brain can move freely inside
the skull while venous sinuses are fixed
Clinically - begin within 48 h after trauma, located at the lateral aspects of the cerebral
hemispheres. Headache and confusion-
- lysis of the clot(1 week)
- organization of clot (2 weeks)
- hyalinized connective tissue firmly attached to dura but not in arachnoid (1-3 mo)
Post-traumatic hydrocephalus & dementia - Answer Sequelae of Brain Trauma
Global Cerebral Ischemia - Answer Cardiac arrest, shock, severe hypotension
In mild cases - transient post-ischemic confusional state, complete recovery, no tissue
damage
In severe cases - widespread brain infarction, pts. impaired neurologically and deeply
comatose - persistent vegetative state. Brain death - isoelectic \"flat\" EEG, MRI; brain
stem damage (absent reflexes and respiratory drive, absent perfusion). Autolysis of the
brain.
Stroke (Focal Cerebral Ischemia) - Answer a sudden loss of consciousness resulting
when the rupture or occlusion of a blood vessel leads to oxygen lack in the brain d/t
thrombosis, arteritis or embolism
Intracerebral Hemorrhage - Answer Spontaneous intraparenchymal hemorrhages
occurs in individuals over 60y associated with HTN, heart surgery, neoplasms
Subarachnoid Hemorrhage (Ruptured berry aneurysm) - Answer bleeding caused by a
ruptured blood vessel just outside the brain ) that rapidly fills the space between the
brain and skull (subarachnoid space) with blood; the patient may experience an intense,
sudden headache accompanied by nausea, vomiting, and neck pain. Associated with
,PKD and Marfan
AV Malformation - Answer a tangle of numerous, abnormally tortuous, misshapen
vessels. Males, ages 10-30y
Clinically - seizure, intracerebral or subarachnoid hemorrhage in the territory of middle
cerebral artery
Hypertensive Cerebrovascular Disease - Answer what has the eddect of hypertensive
intercerebral hemorrhage, lacunar infarct, slit hemorrhage, and hypertensive
encephalopathy and it affects the deep arterioles that supply the basal ganglia, white
matter, brain stem makes the arteriolar wall get weaker w chronic hypertension causes
Charcot-Bouchard microaneurysms and can rupture
Acute Pyogenic (Bacterial) Meningitis - Answer It is an inflammatory process of the
leptomeninges and CSF within the subarachnoidal space
Due To: - E. coli, group B streptococci (neonates)
- H. influenzae (infants, children)
- N. meningitidis (adolescents, young adults)
- Streptococcus pneumoniae, Listeria monocytogenes (elderly)
- Klebsiella or anaerobics (immunosuppressed)
Acute Pyogenic (Bacterial) Meningitis - Answer - Fever, headache, photophobia,
irritability, clouding of consciousness, and neck and back stiffness. Kerning and
Brudzinski positive
CSF: neutrophilia, increase pressure, increased protein, MARKEDLY decreased glucose
Acute Aseptic Meningitis - Answer absence of recognizable organisms w/ meningeal
irritaton, fever, alterations of consciousness
less fulminant that pyogenic (bacterial) meningitis
usually self limiting
Acute Aseptic Meningitis - Answer CSF - lymphocytic pleocytosis, moderate protein
elevations, normal sugar content
no bacteria in culture or smear
(note, if chemical, can have neutrophilia in CSF)
Brain abscess - Answer an accumulation of pus within the brain tissue that can result
from a local or a systemic infection from another source, such as the skull, sinuses, or
other structures in the head.
, liquefactive necrosis, surrounded by fibrosis, and edema
Brain abscess - Answer CSF - increased pressure, increased WBC and proteins, normal
sugar content
Chronic Bacterial Meningoencephalitis - Answer Headache, malaise, mental confusion,
and vomiting
gelatinous or fibrinous exudate at the base of the brain involving the cranial nerves.
single, well-circumscribed Intraparenchymal mass of several cm composed of caseous
necrosis, surrounded by granuloma infiltrate, and calcifications
Chronic Bacterial Meningoencephalitis - Answer CSF - pleocytosis with mononuclear
cells, or neutrophils and mononuclear cells, markedly elevated proteins, glucose
content is normal or moderately reduced
Tuberculosis, Neurosyphilis (Treponema pallidum), Neuroborreliosis (Borrelia
burgdorferi- Lyme Disease) - Answer These are the three types of Chronic Bacterial
Meningoencephalitis
neurosyphilis - Answer this isdeveloped during tertiary stage of syphilis in 10% of
patients left untreated. Patients with HIV are at increased risk
is a chronic meningitis involving the base of the brain, cerebral convexities, and spinal
leptomeninges. It may be associated with obliterative endoarteritis and cerebral
gummas. Seizure, hemiparesis, hemiplegia.
Viral Meningoencephalitis - Answer Can be Arthropod-borne (Arbo) Viral Encephalitis,
HSV-associated, Varicella-zoster, cytomegalovirus, poliomyelitis, rabies, HIV
associated
reflex asymmetry, ocular palsies, seizure, confusion, delirium, stupor or coma.
lymphocytic meningoencephalitis, multiple foci of necrosis of gray and white matter,
viral antigens inside the neurons, neuronophagia, gliosis
Viral Meningoencephalitis - Answer CSF - colorless, slightly elevated pressure,
neutrophilic and lymphocytic pleocytosis, elevated protein levels, normal sugar content
HSV1 encephalitis - Answer It causes encephalitis in children and young adults
Clinically - alteration in mood, memory, and behavior. Subacute manifestations -
weakness, lethargy, ataxia, seizure
Morphology - encephalitis involves the temporal lobes, orbital gyri of the frontal lobes.
Histology - necrotizing and hemorrhagic lesions with intranuclear viral inclusion bodies
in neurons and glia.
HSV2 encephalitis - Answer It causes severe encephalitis in 50% of neonates born by
vaginal delivery to women with active primary HSV genital infection