CNS Syndromes Flashcards
Ischemic stroke / TIA Description Focal / diffuse? Onset Cause Population Lacune Central venous sinus thrombosis Gross pathology
Stroke = infarct
TIA = ischemia
Focal
Acute
Atheroembolism is most common cause. Next is embolism from A fib.
Seen most often in middle-aged and elderly. More females than males (possibly b/c women live longer).
Lacune - subcortical
Central venous sinus thrombosis may be asymptomatic, but usually has a static or slowly progressive headache over days to months.
Gross pathology – focal softening, edema, sulcal effacement, hemorrhage, asymmetric herniation, focal atrophy / gliosis / cavitation.
Nontraumatic intracerebral hemorrhage Focal / diffuse Onset Age Risk factor Cause Association w/ AD Most common sites Consequences of bleeding
Focal
Acute
Most common in middle aged / elderly
Risk factor - old age and chronic HTN
Cause – old age and chronic HTN → degeneration of arteries → sudden rupture.
•Repeated episodes commonly occur in cerebral amyloid angiopathy, which is associated w/ AD.
•Most common areas involved from most to least: putamen, thalamus, deep cerebellar nuclei, pons, superficial cerebral hemispheric white matter. Same areas that lacunes occur.
•Severe forms may involve large hematoma, edema, intraventricular bleeding, hydrocephalus, sulcal effacement, asymmetric herniation, cerebral atrophy, gliosis, and hemosiderin staining (blood in macrophages).
Intracranial vascular malformation Description Focal / diffuse Onset Sxs Age Risk factor Pathology
Intracranial hemorrhage or ischemic steal caused by abnormal blood vessels. Most are congenital. May involve dural arteriovenous fistulas or aneurisms. High flow (such as fistulas) are high risk. Venous malformations are low flow / low pressure and are lower risk.
Focal
Acute
Most are asymptomatic. Sxs include headaches, focal seizures, and pulsatile tinnitus.
•Most commonly affects young adults and middle aged.
•Risk factor – family hx of hereditary hemorrhagic telangiectasia
•Pathology – Arteriovenous malformations w/o intervening capillaries are most common causes. May be evidence of calcified / gliotic brain tissue. Other signs include dilated / thin-walled veins, cavernous malformations (tangle of dialted capillaries), and capillary telangiectasias (less-dilated capillaries)
Mechanical myelopathy Focal / diffuse Onset Population Risk factors for non traumatic Which levels of SC are most often involved? Spinal stenosis Pathology
Focal
Acute
•Most commonly occurs in young adults (trauma) and middle aged / elderly (nontraumatic). Affects more males than females.
•Primary risk factor for nontraumatic injuries is spondylosis. Other causes include neoplasm, abscess, or hemorrhage along SC.
•Cervical and thoracic SC levels are most often involved.
•Spinal stenosis – narrowing of spinal canal. Causes episodic myelopathy w/ prolonged standing and is relieved w/ trunk flexion. Presents w/ bilateral leg pain w/ walking called neurogenic claudication.
•Pathology – hemorrhage, edema, neuronal / axonal loss, gliosis, cavitation.
Transient global amnesia Description Focal / diffuse Onset Age Risk factors Sign Prognosis
Anterograde amnesia often w/ brief period of retrograde amnesia. Rapid onset. Resolves w/in 1 day.
Focal
Acute
Middle aged / elderly
Risk factors - increased intrathoracic pressure (valsalva) and intense emotions
Broken record sign
Usually only have 1 episode per lifetime. If recurrent, ti may be epilepsy.
Pituitary adenoma How common? Focal / diffuse Onset Sxs
Occurs in 17% of people but sxs are rare. Most common intracranial neoplasm.
Focal
Gradual
Hypersecretion of hormones from tumor or hyposecretion of hormones from other parts of pituitary that are being compressed. Most common hypersecretion is a prolactinoma → galactorrhea, amenorrhea, infertility, or impotence.
Bitemporal hemianopsia
Meningioma Description Focal / diffuse Onset How common? Population Risk factors Pathology
Extra-axial tumor. Usually singular. Most cases start from arachnoid cells.
Usually asymptomatic. Tumor compresses w/o infiltrating adjacent brain tissue. May cause slowly progressive focal CNS syndrome w/ or w/o intracranial HTN.
Focal
Gradual
2nd most common intracranial neoplasm.
•Most commonly affects middle aged / elderly. More women than men.
•Risk factors – radiation exposure and neurofibromatosis (genetic)
•Pathology – usually see spindled cells resembling fibroblasts arranged in whorls. May be calcified / highly vascular areas. Growth may be encouraged by estrogen.
NS Metastasis Description Age Risk factor How common? Which cancers metastasize? Brain vs SC
- Focal or multifocal, often involving intracranial HTN, w/ or w/o sudden onset focal syndromes from seizure or hemorrhage. Tumors often found in the superficial white matter of brain near cortex. Most tumors have surrounding edema.
- Most commonly affects middle aged / elderly
- Most important risk factor is cigarette smoking
- Metastases are 3rd most common intracranial neoplasm and most common spinal canal neoplasm. Less commonly affects PNS.
- Most common cancers to metastasize to CNS in order: lung, breast, melanoma, colorectal, and hematologic
- Progression is faster in SC than brain due to less room.
Astrocytoma
Description
Population
Adults vs kids
- Usually a single tumor in the brain. Causes focal CNS syndromes often w/ intracranial HTN, w/ or w/o sudden onset syndromes caused by seizures / hemorrhage.
- Affects all age groups. More men.
- Kids have more brainstem and cerebellar tumors (infratentorial). Adults have more cerebral tumors (supratentorial)
Parkinson's Disease Gender Sxs Protein What is the phrase that means to fall backwards?
Affects more men.
Anosmia, REM sleep behavior disorder, constipation, drooling, gait freezing on initiation or at thresholds (doorways)
•Synuclein protein is a major component of Lewy bodies and may play a role in neuronal loss
•Retropulsion – fall backwards
Focal seizures
Age
Most common sites for focal seizures
Most common aura
Most commonly affects middle aged / elderly.
•Most common site for focal seizure is medial temporal lobe, possibly due to highly plastic nature of hippocampus.
•Most common aura is unpleasant olfactory hallucination due to early seizure spread from hippocampal area to primary olfacatory cortex (both in medial temporal lobe).
Dystonia Description Focal / diffuse Onset Most common dystonias in order (3 kinds) Segmental dystonia
Involuntary muscle contractions. May see hypertrophy of chronically affected muscles and an irregular tremor w/ movements that stretch the involved muscles.
Usually focal
Episodic
•Most common dystonias in order:
• Cervical dystonia (aka torticolis) – involuntary neck rotation, flexion, extension, lateral flexion, or combo
• Blepharospasm – involuntary eye closure
• Task-specific dystonias – occurs during a frequently repeated skilled movement, such as handwriting (called “writer’s cramp”), or playing an instrument. Involuntary flexion or extension of fingers.
•Segmental dystonia - Progresses to involve more than one body area
Multiple Sclerosis Description Most common sites of involvement' Associated sxs Population 3 types Gross pathology Active vs inactive plaque Microscopic pathology Treatment
Autoimmune attack of oligodendrocytes → demyelination. Cellular and humoral immunity. Subacute attacks separated in space and time.
•Common involvement in optic nerve, near the ventricles and pons.
•Optic neuritis is most common syndrome in MS. Consists of monocular visual loss w/ afferent pupillary defect and pain on eye movement. Afferent pupillary defect often persists even when visual deficits resolve (good clue).
•Other features include chronic fatigue and Uhthoff’s phenomenon (transient worsening of deficits w/ increased body temp)
•Most often affects young adults. More women.
•Relapsing-remitting MS – most common type. Shows attacks separated by space and time.
•Primary-progressive MS – less common, gradually progressive course
•Secondary-progressive MS – occurs after initial relapsing-remitting course.
•Gross pathology – white matter plaques (may be anywhere in CNS but most often in optic nerves, cervical SC, periventricular cerebral hemispheres, pons, and cerebellum) and global cerebral atrophy if chronic.
•Microscopic pathology –
• Active plaque: demyelination, increased macrophages containing myelin, increased lymphocytes, increased astrocytes
• Inactive plaque: gliosis and variable demyelination / remyelination
• Plaques are often seen on venules
• May involve deposition of complement and Ig
•Tx w/ high dose steroids (autoimmune)
Neurocysticercosis Description Sxs Focal / diffuse Onset
Larva of pork tapeworm (Taenia solium) → cysts in brain. Most pxs are asymptomatic. Most common sx is seizures. Others include intracranial HTN, hydrocephalus (if cyst blocks ventricular system), cranial neuropathy or ischemic stroke (from compression of nerves / vessels)
Focal
Episodic
Global cerebral hypoxia / hypoglycemia / ischemia
Age
Most common syndrome
Affects all ages but middle aged / elderly are at highest risk for severe cases.
Most common syndrome is brief / mild presyncope (feeling light headed) due to hypotension → ischemia. May involve blurred / gray vision, decreased hearing, generalized weakness, feeling warm, diaphoresis, nausea, pallor, yawning, confusion, or shuddering. If severe, syncope occurs.
Convulsive syncope
Fainting w/ generalized myoclonic movements. Often mistaken for seizures. Movements are often arrhythmic, as opposed to rhythmic in a seizure. Another thing to help differentiate is presyncope rather than an aura preceding the loss of consciousness. Pallor (white) is seen w/ presyncope, while blue / red skin is seen w/ seizures. Usually recover w/in seconds w/o a post-ictal state w/ syncope. Tongue biting and incontinence are rare in syncope but common w/ seizures.
Vasovagal / neurocardiogenic syncope
Most common form of syncope. Triggered by something that produces a strong emotional reaction (fainting at sight of blood) or prolonged standing (passing out at church).
•Usually caused by inappropriate cardiovascular reflex that leads to systemic vasodilation and decreased CO. May involve sympathetic output that is quickly reversed / overpowered by parasympathetic output.
•Both hypotension and bradycardia precede the event.
•More common when people are warm or dehydrated.
What population is most often affected by orthostatic syncope?
Elderly and diabetic due to autonomic neuropathy. Can’t vasoconstrict.
Cardiogenic syncope
Cause
Difference from other types of syncope
Risk factors
Caused by cardiac abnormality, most often brady / tachyarrhythmia. AV node dysfunction is most common cause of bradyarrhythmia. Often lacks a trigger, presyncope, and other warning signs (different than 2 other types of syncope). If it lasts long enough it may cause brain damage.
•Risk factors – old age, MI, ventricular dilation
Most common parts of brain affected by syncope and associated sxs
Anterograde amnesia from hippocampal injury, gait / limb ataxia from cerebellar injury, generalized myoclonus (from BG injury).
Pathology of ischemia / syncope
- Lack of O2 / nutrition → failure of Na/K pumps → AP failing. Na influx is followed by water → intracellular edema.
- Ca influx occurs due to depolarization, and is associated w/ apoptosis.
Post-concussion syndrome
Headaches, subtle cognitive abnormalities such as poor concentration or emotional dysregulation
Osmotic neural syndromes Description Focal / diffuse Onset Age Risk factors Most common syndrome Caution
Hypoosmolality causes diffuse cerebral cortical dysfunction or rarely cerebral edema. Rapid rise in osmolality may cause cerebral demyelination.
•Cerebral edema may cause decreased arousal, generalized seizures, or intracranial hypertension.
Diffuse
Acute
•Most commonly affects middle aged / elderly
•Risk factors – old age, diuretic use, and heavy alcohol consumption
•Most common syndrome is delirium
•Rapid increase in osmolality (usually iatrogenic overcompensation to fix hypoosmolarity) may cause demyelination, especially in the pontine white matter, called central pontine myelinosis → quadriparesis, cranial neuropathies, or decreased arousal. Severe cases may cause locked-in syndrome or coma.
Aneurysmal Subarachnoid Hemorrhage Description Focal / diffuse Onset How common? Population Risk factors Complications Main difference from other headaches Eye involvement CSF
•Thunderclap headache w/ or w/o brain dysfunction.
•Most common cause of subarachnoid hemorrhage is trauma. Most common nontraumatic cause is rupture of saccular aneurysm.
•Aneurysm rupture is most common at branch points in the circle of Willis.
•Mycotic aneurysm may develop from septic emboli in bacterial endocarditis
•Thunderclap headache is sudden onset and feels like a bomb went off in their brain. May involve neck pain and guarding (nuchal rigidity).
•Dysfunction of arachnoid villi may cause communicating hydrocephalus
Diffuse
Acute
•Unruptured brain aneurysms are common, seen in 3% of people.
•Most commonly affects middle aged / elderly. More females than males.
•Risk factors – polycystic kidney disease and family hx of intracranial aneurysm. Weak risk factor is smoking.
•Same complications as ischemic stroke may occur, including early seizures, later epilepsy, disability, and death.
•Main difference b/w normal headache is speed of onset
•Unruptured, growing aneurysm on posterior communicating artery may compress the oculomotor nerve → isolated oculomotor neuropathy. This is important to recognize due to high risk of rupture. Down and out.
•Pathology – RBCs are found in CSF and turn yellow after a couple hours due to Hb breakdown, called xanthochromia
