CNRN Review


Type of glioma; astrocytes maintain the health of nerve cells and help form BBB. Multiple types: brainstem gliomas, pineal astrocytic tumors, pilocytic astrocytomas (form in the brain or spine), diffuse astrocytomas (cerebral), anaplastic astrocytomas/gli

Distal Symmetrical Peripheral Neuropathy (DSPN)

Complication from AIDS that begins with myelopathy (progressive weakness of lower extremities), then leads to spinal cord damage causing gait dysfunction, leg weakness, and incontinence. Symptom of late-stage HIV/AIDS.

Bell's Palsy

Temporary irritation of the facial nerve causing unilateral facial paralysis due to inflammation or compression of CNVII. Mostly from herpes virus, but some are idiopathic. Patients usually recover within a few weeks, but some retain weakness.
Symptoms: p

Acute Disseminating Encephalomyelitis (ADEM)

Acute form of demyelinating polyneuropathy. Autoimmune response after an infection (usually viral) causing abrupt inflammation in the brain and spinal cord and subsequent demyelination. Symptoms appear 1-2 weeks post-infection. Most recover but some retai

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)

Autoimmune disorder causing demyelination; chronic symptoms of Guillain-Barre. Slow disease progression or relapse pattern.
Symptoms: motor - muscle weakness, impaired gait, absent reflexes; sensory - numbness and tingling of affected muscles; respiratory

Guillain-Barre Syndrome (GBS)

AKA Acute Demyelinating Polyneuropathy. Paralysis caused by an autoimmune attack on peripheral myelin, causing weakness and ascending paralysis of the limbs, face and diaphragm. Usually precipitated by viral infection 1-3 weeks prior (70%). Most patients

Multiple Sclerosis (MS)

Autoimmune disease that attacks the myelin surrounding neuron axons, causing demyelination. Women>Men. Onset 20-40 years. Myelin loss causes focal lesions and plaques, which appear in multiple areas. Myelin normally helps propogate neural transmissions, s

Myasthenia Gravis (MG)

Autoimmune disorder affecting the function of acetylcholine receptors at the neuromuscular junction. Acetylcholine is released from motor neurons and stimulates muscle contractions; therefore, receptor failure diminishes voluntary muscle control. Women>Me

Creutzfeldt-Jakob Disease (CJD)

Type of transmissible spongiform encephalopathy (from prions). Can be sporadic (85%), inherited, or from ingesting infected animal tissues. Mostly sporadic. Prions accumulate and form plaques in nervous tissue, destroying neurons and creating widespread h


Brain disease occurring when systemic disease impairs brain health and function. Can be from hepatitis, cirrhosis (hepatic encephalopathy); diabetes, renal artery stenosis, renal failure (renal or uremic encephalopathy); cardiac arrest, drowning, birth as

Lyme Disease

Disease caused by a spirochete transmitted from ticks. Most recover without any permanent deficits, but some have chronic fatigue and joint problems.
Symptoms: bullseye rash around site of bite, headache, fatigue, flulike symptoms (early); headache, neck


Nervous system infection by the encysted larval form of a pig tapeworm (taenia solium). Caused by ingestion of tapeworm eggs through contaminated food or water. Eggs hatch in the GI tract, enter the bloodstream, then migrate to the muscle, eye, or brain.

Pseudoseizures (Psychogenic Nonepileptic Seizures)

Seizurelike activity from emotional or stress-related psychological issues (as opposed to an abnormal electrical discharge from the brain). Involuntary but considered somatoform.
Treatment includes psychotherapy and medications to treat the underlying anx

Simple Partial Seizure

A seizure affecting only one part of the brain without an alteration in consciousness. Symptoms depend on focal location of the abnormal activity. Treatment can include antiepileptics or possible surgical excision of abnormal tissue if identified. Vagus n

Complex Partial Seizure

A partial seizure, starting from a focus and remaining localized, that produces loss of consciousness and automatisms (involuntary repetitive motor activity)
Treatment can include antiepileptics or possible surgical excision of abnormal tissue if identifi

Generalized Seizure

A seizure that involves most of the brain, as contrasted with a partial seizure, which remains localized. Involves generalized bilateral discharge of electrical activity. Includes multiple types of seizures, including tonic-clonic and absence seizures.

Tonic-Clonic Seizure

Generalized seizure involving a tonic phase (voluntary muscle contraction/stiffness/rigidity) and clonus (contractions become rhythmic and repetitive, hyperventilation, excessive salivation). Post-ictally, clonic movements slow and the patient awakens dis

Absence Seizure

Form of generalized seizure consisting of momentary clouding of consciousness and loss of awareness of surroundings

Status Epilepticus

A prolonged seizure or situation when a person suffers two or more convulsive seizures without regaining full consciousness between episodes.

Arnold-Chiari Malformation (Cerebromedullary Malformation Syndrome)

Developmental deformity characterized by an abnormally small posterior fossa and herniation of the cerebellar tonsils that may protrude into the spinal column, obstructing CSF flow and compressing the brainstem. 3 types based on severity. Type one is mild


Abnormal, longitudinal, fluid-filled cysts (syrinx) in the spinal cord causing paresthesias and muscle weakness. May be caused by Arnold-Chairi malformations, obstructed CSF flow, SCI, hemorrhage, infection, injection, or tumors.
Symptoms: headaches, pain

Cerebral Palsy

Paralysis caused by damage to the area of the brain responsible for movement
Symptoms: increased muscle tension, seizure, intellectual disability (some)
Treatment: focused at symptom relief (muscle spasticity meds, ROM)

Spina Bifida

Congenital defect resulting in the failure of the neural tube to close completely. May be closed (occulta) or open (aperta). Open spinal bifida causes meningeal sacs to protrude from the spinal cord.
Symptoms: inability to move legs in utero causing club


Most severe form of spina bifida; herniation of spinal meninges that protrudes beyond the spine and involves the cord. Causes deformity and exposure of neural tissue. Associated with Arnold-Chiari Type II. Mostly lumbosacral.
Symptoms: weakness, paralysis

Benign Essential Tremor

Tremor involving bilateral hands and forearms that occurs while a posture is maintained or while performing voluntary movements (as opposed to Parkinsonian rest tremors). Most common movement disorder. Alcohol improve symptoms; not present while asleep.


Premature skull suture closure in newborns. May involve one or multiple sutures. Single-suture synostosis (one suture) results in a normal newborn. Multiple synostoses may be nonsymptomatic or symptomatic and lead to systemic problems.
Frequent head measu


Sac composed of dura and arachnoid protrudes through the spinal defect; also the name for the sac itself; type of spina bifida aperta

Complex Regional Pain Syndrome II (CRPS-II)

AKA causalgia; traumatic nerve injury causes hyperpathia and psychomotor dysfunction
May be relieved via rhizotomy (destroys dorsal sensory nerve root while preserving motor fiber), cordotomy (disables selected pain-conducting tracts in the spinal cord)

Trigeminal Neuralgia

Condition caused by compression of the trigeminal nerve due to an atherosclerotic artery, trauma, or local infection.
Symptoms: intense/burning pain in the sensory portion of the trigeminal nerve that occurs periodically. Facial contortions are common res


forward slipping of one vertebra over another due to diminished cushioning of the disc
usually age-related; discs lose blood supply, dehydrate, and start to deteriorate, which can lead to disc herniation and slippage
may cause nerve root irritation, causi


condition in which vertebrae contact each other (usually from degeneration) and form bony growths (osteophytes); vertebrae may fuse and lead to spinal cord injuries

spinal stenosis

narrowing of the spinal canal with compression of nerve roots; usually age-related; may occur with spondylosis or spondylolithesis
Symptoms depend on location (usually lumbar) include nerve root irritation (pain and weakness in lower extremities) and loss

ankylosing spondylitis

a form of rheumatoid arthritis that primarily causes inflammation of the joints between the vertebrae

Friedreich's ataxia (spinocerebellar degeneration)

rare genetic defect that attacks muscles and the heart caused by mutations of the FXN gene on chromosome 9, which leads to degeneration of nerve tissue in the spinal cord
young onset and rapidly progressive
symptoms: vision changes (esp color), jerky eye

Communicating Hydrocephalus

accumulation of CSF caused by defective CSF absorption, venous drainage insufficiency, or CSF overproduction
full communication between the subarachnoid space and the ventricles is present
treatment: meds (decrease CSF secretion in the choroid plexus or i

Amaurosis fugax

painless temporary vision loss in one or both eyes
can be associated with carotid stenosis

homonymous hemianopsia

loss of half of the field of view on the same side in both eyes


the inability to perceive multiple stimuli of the same time simultaneously; associated with right-sided strokes

verterobasilar insufficiency

poor blood flow (ischemia) to the brainstem; can lead to brainstem strokes
symptoms: ataxia, global amnesia, vertigo, vision changes, tinnitus, altering hemiparesis, drop attack

cerebral vasospasm

narrowing of the arteries post-brain hemorrhage (can occur up to 21 days after). Diagnosed based on the amount of blood the subarachnoid space. Leading cause of death after SAH; causes ischemia
Treatment: BP>160, angioplasty, stenting
Triple H Therapy

Todd's Paralysis

Reversible weakness following a seizure; may last up to 36 hours post-ictal (average = 15 hours). Very important to distinguish from a stroke!
symptoms: hemiparesis; may affect speech and vision

Jacksonian March Seizure

AKA sequential seizure, type of simple partial seizure that spreads from one muscle or sensory group to another

Brown-Sequard Syndrome

damage/infarct of lateral 1/2 of spinal cord
symptoms: ipsilateral motor/vibration/proprioception loss, contralateral sensation loss

Spinal Shock

complete but temporary loss of motor, sensory, reflex, and autonomic function immediately after injury- lasts less than 48hrs-12 weeks
Improvement checked with BCR reflex
Sx: loss of autonomic function/flaccid paralysis, then spasticity/hyperreflexia as s

Kernig's Sign

a diagnostic sign for meningitis marked by the person's inability to extend the leg completely when the thigh is flexed upon the abdomen and the person is sitting or lying down

Brudzinski's Sign

ZSign of meningitis; positive when a patient's legs lift involuntarily when lifting a patient's head

Diffuse Axonal Injury (DAI)

Widespread disruption of axons due to acceleration or deceleration injury.
Symptoms vary based on location and severity, but some can lead to a persistent vegetative state.
Treatment involves draining clotted blood, reducing/accommodating brain swelling,

Acute Subdural Hematoma

Hemorrhage occurring in the subdural space between the dura mater and the arachnoid layers. They are composed of clotted blood and occur 24-72 hours after injury.
Symptoms depend on location and size. May show signs of increasing intracranial pressure, he

Chronic Subdural Hematoma

Hemorrhage occurring in the subdural space between the dura mater and the arachnoid layers. They develop slowly (21 days or more after injury) and are composed of fluid blood (encapsulated hematoma).
Symptoms develop slowly and include headache, confusion

Epidural Hematoma

Hemorrhage in the cavity between the skull and the dura mater caused by tearing of the middle meningeal artery. More common in younger patients. Usually occurs with a temporal skull fracture.
Symptoms include confusion, dizziness, drowsiness, ipsilateral

Transient Ischemic Attack (TIA)

Mini stroke" causing temporary deficits that clear within 24 hours. May be a warning sign before a large-vessel stroke.
Symptoms depend on location and can include ipsilateral blindness, contralateral numbness of face/limbs, altered LOC, aphasia, behavio

Cavernous Angioma

Abnormal arrangement of vein-like structures with little blood flow within the brain and the spinal cord. Symptomatic when bleeding. Bleeding creates pressure, which causes deficits based on location.
Treatment: monitoring via imagery every 2 years, sympt

Carotid Artery Dissection

Arterial wall hematoma that tears and ultimately narrows the carotid lumen. May occur spontaneously (usually from preexisting conditions) or due to trauma including chiropractics or coughing.
Symptoms are progressive and include tinnitus, bounding pulse,

Vertebral Artery Dissection

Tearing of the inner lining of the vertebral artery (supplies blood to brain). Occurs with trauma and overuse (yoga, martial arts, neck strain). Blood accumulates and eventually causes occlusion.
Symptoms may be delayed for years and include severe occipi

Right Hemisphere Stroke - Symptoms

distractible/impulsive, flat affect, left-sided neglect/paralysis/vision loss, extinction

Left Hemisphere Stroke - Symptoms

aphasia, agraphia, cognitive impairment, right-sided deficits

Posterior Cerebral Artery (PCA) Stroke

The posterior cerebral artery (PCA) supplies the temporal and occipital lobes, as well as cerebellum, brainstem, and spine.
Symptoms include dysarthia, dysgraphia, diplopia, bilateral blindnes, sensorimotor deficits, quadriparesis, and memory deficits

Cerebellar Stroke

Ischemia to the cerebellar arteries, which branch off from, the posterior cerebral artery, causes deficits with motor coordination (ataxia, vertigo, nystagmus, dizziness)

Middle Cerebral Artery (MCA) Stroke

Ischemia of the middle cerebral artery (MCA), which branches off from the internal carotid and supplies the lateral cerebrum. Most common type of stroke.
symptoms: motor/sensory deficits of the face and/or limbs on the contralateral side (arms greater tha

Anterior Cerebral Artery (ACA) Stroke

Ischemia of the anterior cerebral artery (ACA), which branches from the internal carotid artery and supplies the frontal and parietal lobes
symptoms: contralateral hemiparesis (lower greater than upper extremities), personality changes, lack of initiative

Lacunar Stroke

Strokes caused by ischemia of small, deep arteries. Ischemia leads to infarcted tissue, which degenerates and leaves a cavity (lacuna). Common in basal ganglia, thalamus, internal capsule, and pons. Usually caused by small vessel wall thickening, hyperten

Intracerebral Hemorrhage

bleeding into the brain as a result of a ruptured blood vessel within the brain; most common type of hemorrhagic stroke
Symptoms steadily worsen as blood accumulates and include one-sided numbness/weakness, dysphagia, receptive aphasia, confusion, visual

Intraventricular Hemorrhage

Bleeding that occurs from vessels along the ventricles into the deep CSF-filled spaces of the brain. Common in premature infants due to fragile blood vessels.

Subarachnoid Hemorrhage (SAH)

Bleeding between the brain and the membrane covering it caused from
aneurysm rupture
(berry aneurysm) or trauma. May be from AVMs. 33% lethal.
usually in the anterior circulation
higher risk with connective tissue disorders (Ehlers-Danlos; Marfan)
Sx: "wo


Malignant tumor of oligodendrocytes (makes up myelin); rare and slow-growing. Mean survival time 3-5 years with treatment.
most seizure-generating tumor type
grade two astrocytoma

Embryonic Brain Tumor

Tumors may develop in fetal brain and spinal tissue during development. Highly malignant.
Medulloblastoma - up to age 20; causes cerebellar sx (ataxia)
Primitive Neuroectodermal Tumor (PNET) - muscle/melanocytic cells; aggressive
Prognosis depends age of

Neurofibromatosis Type 1 (Von Recklinghausen's Disease)

Autosomal dominant genetic condition causing tumors (neurofibromas) that arise from the nerve sheath of cranial and spinal nerves. Tumors arise in childhood. Chromosome 17 abnormality.
Symptoms: skin hyperpigmentation (cafe au lait spots), small tumors in

Neurofibromatosis Type 2

Genetic disorder involving benign schwannomas found on the acoustic nerve (acoustic neuroma) in the peripheral nerve sheath
Symptoms: hearing loss, tinnitus, vertigo; may affect facial, trigeminal, and glossopharyngeal, and vagus nerves and have associate


Tumors that form in the thin tissue layers covering the brain and spinal cord (meninges). 3 Grades:
1) most common; prevalent in women; benign and slow-growing; form in meninges
2 and 3) prevalent in men; rare; malignant and fast-growing; spread within br


Tumor of lymph nodes and lymph tissue and could arise anywhere in the brain. More common in immunocompromised patients. Usually malignant and recurring. Highly vascular.
Treatment: surgery, radiation, autologous peripheral stem cell transplantation

Von Hippel-Lindau Disease

A hereditary disease that includes the development of noncancerous blood vessel tumors found in the retina, brain, and spinal cord, as well as kidney and adrenal gland tumors. Median life expectancy of 50 years. Death mostly commonly from capillary hemang


Highly vascular tumors that typically arise in the cerebellum (esp. common in von Hippel-Lindau disease); secrete erythropoietin and can induce polycythemia.
Treatment: surgical excision (curative), vascular embolization to reduce tumor vascularity

Pituitary Tumor

Cause excessive secretion of hormones and/or adjacent nerve compression (mostly the optic nerve).
Treatment: surgical resection, hormone replacement

Pineal Tumors

Tumor of the pineal gland, which produces melatonin. Found in adults. 3 types:
1) Pineocytomas - slow-growing; variable prognoses
2) Pineoblastomas - rare; highly malignant; embryonal; poor prognosis
3) Pineal Parenchymal Tumors - unpredictable


A congenital tumor arising from Rathke's pouch of the pituitary. Affects endocrine function and may compress the optic nerve.
Symptoms: growth retardation, visual disturbances, increased ICP (from ventricle compression)
Treatment: Surgery, radiation, horm


Primary tumors derived from ependymal cells (line ventricles and spinal canal). Most common in male children/young adults.
May attach to the ventricle wall and grow into the cerebrum via CSF transport. May obstruct CSF flow and cause hydrocephalus and oth

Bacterial Meningitis

disease diagnosed by low glucose in the CSF
can cause damage to cranial nerve VIII

Central Venous Thrombosis

clot in the superior sagittal sinus (in the falx cerebri) that presents with vague focal neurologic deficits and headache

tau protein

when found in CSF, can indicate dementia

Arterio-Venous Fistula

abnormal connection between arteries and veins in cerebral or spinal cord
typically find in the dura/arachnoid mater
develops from infection/trauma (not congenital)
Sx: tinnitus, eye pain, impaired memory, hemorrhagic stroke

Arterio-Venous Malformation

a condition in which arteries and veins connect abnormally without capillaries between them
typically found inside the brain or spinal cord
usually congenital and sx develop over time

Posterior Reversible Encephalopathy Syndrome (PRES)

Severe hypertension leading to interruption of brain autoregulation; typically seen in patients with advanced kidney disease, or those on immunosuppressants
Sx: headache, seizures, confusion, visual disturbances
Subcortical vasogenic edema seen on MRI

Frontal Lobe

part of the brain involving higher cognitive function, speech, ipsilateral motor control, emotions

Temporal Lobe

part of the brain involving hearing, memory, speech perception
Most common site of seizures

Parietal Lobe

part of the brain involving sensory integration

Occipital Lobe

part of the brain involving vision and vision perception


part of the brain that relays impulses to and from the brain and contains the major motor nerves for eye movement (CN 3 & 4)


part of the brain containing the reticular activating system (circadian rhythm); origin of CN 5-8

Medulla Oblongata

part of the brain that contains many motor and sensory pathways that unite the brainstem, cerebellum, and cerebrum; controls heart rate and respiration; origin of CN 9-12

Cushing's Reflex

physiological nervous system response to increased intracranial pressure that results in triad of increased blood pressure, widening pulse pressure, irregular breathing, and bradycardia; may indicate brain herniation

Brain Death Determinants

- caloric reflex test (COWS)
- Doll's eyes
- corneal reflex (absence = pons dysfunction)
- cough/gag reflex
- no normothermia
- no cerebral blood flow (cerebral perfusion study)
varies state to state

Basilar Skull Fracture (symptoms)

battle sign, raccoon eyes, rhinorrhea, otorrhea, +glucose in CSF, Halo sign
Anterior fossa (frontal/ethmoid/sphenoid fracture) - raccoon's eyes, rhinorrhea
Middle fossa
- battle's sign, otorrhea, hemotympanum, peripheral facial nerve palsy (CN VII injury)

Wernicke's encephalopathy

A brain disorder caused by thiamine deficiency and characterized by visual disturbances, ataxia, somnolence, stupor, and , without thiamine replacement, death. can be reversible if treated early.

Korsakoff's syndrome

chronic damage to the hippocampus secondary to vitamin B12 deficiency - leads to amnesia, apathy. from chronic alcohol abuse. irreversible.

Cranial Nerve I (olfactory nerve)

cranial nerve that determines sense of smell

Cranial Nerve II (optic nerve)

cranial nerve responsible for sense of vision

Cranial Nerve III (oculomotor nerve)

cranial nerve that determines upward eye movement, eyelid movement, pupil constriction

Cranial Nerve IV (trochlear nerve)

cranial nerve responsible for downward eye movement

Cranial Nerve V (trigeminal nerve)

cranial nerve that determines facial sensation and responsible for clenching teeth and the corneal reflex

Cranial Nerve VI (abducens nerve)

cranial nerve responsible for lateral eye movement

Cranial Nerve VII (facial nerve)

cranial nerve responsible for facial movement and taste to the anterior 2/3 of tongue

Cranial Nerve VIII (vestibulocochlear nerve)

cranial nerve responsible for hearing and proprioception

Cranial Nerve IX (glossopharyngeal nerve)

cranial nerve responsible for swallowing and vocalization; provides taste to the posterior 1/3 of tongue

Cranial Nerve X (vagus nerve)

cranial nerve responsible for swallowing and vocalization; determines heart rate and gastric control

Cranial Nerve XI (accessory nerve/spinal accessory nerve)

cranial nerve responsible for shoulder elevation and lateral head movement

Cranial Nerve XII (hypoglossal nerve)

cranial nerve responsible for tongue movements

Putamen hemorrhage

sx: contralateral hemiplegia with eyes directed toward the hemishphere containing the hemorrhage
most common type of intracerebral hemorrhage
this part of the brain forms complex loop that determines motor movement

Thalamic hemorrhage

sx: contralateral hemiplegia and sensory deficits
this part of the brain relays motor and sensory info to the cerebral cortex

pontine hemorrhage

causes locked-in syndrome
this part of the brain controls sleep/wake cycle and is involved in the control of breathing, communication between different parts of the brain, and sensations such as hearing, taste, and balance.


condition occurring when hypothalamus or pituitary gland is damaged; secretes ADH even though fluid balance is normal
sx: fluid overload, decreased serum sodium, high urine specific gravity

Cerebral Salt Wasting

AKA hypovolemic hyponatremia
condition occurring with hypothalamus/pituitary damage; occurs due to renal loss of sodium
sx: hyponatremia, hypovolemia, increased urine output, increased BUN

Diabetes Insipidus

condition due to hypothalamic damage causing extreme diuresis due to decreased ADH in the body
sx: excessive urination, extreme thirst, poor skin turgor, hypernatremia, increased serum osmolarity
tx: replace ADH and fluids

Spinal Cord Tumors (types)

Intramedullary (within cord)
- usually gliomas
Intradural-Extramedullary (within dura but outside cord)
- can attach to spinal nerve roots
- includes meningiomas, neurofibromas, schwannomas
- typically metastatic; common in elderly
- may cause

Normal-Pressure Hydrocephalus (NPH)

Most common type of communicating hydrocephalus
Characterized by normal intracranial pressures, since CSF increase is slow, allowing gradual increases in ICP to be offset by compression of cerebral hemispheres
sx: "wet, wobbly, and wacky"
may be chronic s


Literaly, "The part of a shadow surrounding the darkest part"
Salvagable ischemic tissue surrounding infarcted tissue following an ischemic stroke; vasogenic edema usually surrounds this

Saccular aneurysm (berry aneurysm)

A slowly progressing aneurysm that affects only a portion of the circumference of the arterial wall and may be the result of congenital anomalies or degeneration.
have characteristic "neck" that can be treated by coiling

Fusiform aneurysm (giant aneurysm)

Large aneurysm that stretches to affect the entire circumference of the arterial wall.
Usually treated by stenting

Charcot-Bouchard aneurysms

small microaneurysms in the brain caused by weakening of arteriole walls secondary to hypertension which may rupture and cause intracerebral hemorrhage