Radsci 350 Nervous System Part 2

Front 1

Stroke Syndrome

Back 1

AKA Cerebrovascular Accident (CVA): the sudden and dramatic development of a focal neurologic deficit.

Front 2

Causes of a stroke

Back 2

Usually occurs due to a blood clot most commonly involving the internal carotid arteries (83% of strokes are the result of ischemic causes). May also be caused by a brain hemorrhage--bleed.

Front 3

Signs and Symptoms of a Stroke

Back 3

One sided weakness, confusion, difficulty talking, nausea/vomitting

Front 4

Diagnosis of a Stroke

Back 4

Non-contrast CT is the modality of choice for evaluation of stroke. IV contrast material is contraindicated b/c it can cross the blood-brain barrier causing additional problems. The initial appearance on CT or MRI is a triangular or wedge shaped area of hypodensity, confined to the vascular area of the involved artery. This exam is done to rule out a bleed. It takes 8-24 hrs following the stroke to visualize its presence on imaging exams.

Front 5

Stroke Treatments

Back 5

If it is ischemic (caused by an embolis): blood thinners; 83% 30-day survival rate.
If it is hemorrhagic: 17% 30-day survival rate, difficult to stop the bleed

Front 6

TIA--transient ischemic attack

Back 6

Short term focal neurologic deficit that completely resolves within 24 hours.

Front 7

Causes of TIA

Back 7

May result from plaque emboli causing temporary occlusion of the cerebral vessels or from stenosis of an extracerebral artery leading to a reduction in blood flow. Most common location of problem lies at the carotid bifurcation. The 5 year cumulative risk of stroke in patients with TIA's may be about 50%.

Front 8

TIA symptoms

Back 8

Signs and symptoms may resemble an early stroke: one sided weakness, difficulty speaking, sudden blindness, dizziness or loss of balance.

Front 9

Diagnosis of TIA

Back 9

Duplex scanning using ultrasound to examine vascular flow; this uses Doppler scanning along with high-resolution ultrasound. Angiography along with digital subtraction typically follows to evaluate the carotid arteries.

Front 10

Treatment of TIA

Back 10

Thromolytic agents, carotid endarterectomy (removal of the internal plaque regions of the artery), antiplatelet therapy, anticoagulants

Front 11

Hemorrhages within the brain

Back 11

Types: Intraparenchymal, epidural, subdural, subarachnoid

Front 12

Intraparenchymal bleed

Back 12

This type of hemorrhage is defined as bleeding INTO the brain tissue. Typically caused by head trauma and hypertensive vascular disease and possibly rupture of a berry aneurysm.

Front 13

Radiographic appearance of an intraparenchymal hemorrhage

Back 13

This type of hemorrhage results in oval or circular collections that displace the surrounding brain and cause a significant mass effect. Most frequently occur in the basal ganglia, white matter, cerebellar hemispheres and the pons. Appears as a homogeneously dense, well-defined lesion with round to oval configuration on a CT.

Front 14

Epidural Bleed

Back 14

Typically caused by head trauma. This type of hemorrhage involves arterial blood causing a "peeling away" of the dura from the brain tissue. This creates a bi-concave space and occurs in an area that is NOT a potential space. Places pressure on the brain causing shifting and grows in size with every heartbeat. This is an emergent situation calling for immediate introduction of a drain.

Front 15

Subdural Bleed

Back 15

This type of hemorrhage involves venous blood filling up the areas of the dura, the gyrus and the sulci. Appears on images as one-sided concavity. Not life-threatening, but may be monitored and if it is large enough, it does require drainage.

Front 16

Subarachnoid Bleed

Back 16

This type of hemorrhage is typically caused by breakage of an aneurysm resulting in bleeding into the subarachnoid space. It cannot be drained because it occurs in the cerebral spinal region. (draining would cause release of CSF). A subarachnoid bleed is highly irritating which may result in necrosis of surrounding tissue structures.

Front 17

Symptoms of hemorrhage within the brain

Back 17

Sudden, severe headache due to change in pressure, neurological deficits such as confusion, nausea and vomitting

Front 18

Treatment of hemorrhages

Back 18

Drainage and possible surgical repair, steroid therapy may help to control the mass effect.

Front 19

Multiple Sclerosis

Back 19

MS is an autoimmune disorder involving the breakdown of the Swann cells that make up the Myelin Sheath of the nerve axons. This causes deterioration of the myelin sheath by the antibodies, replacing it with scar tissue. This results in impaired nerve conduction.

Front 20

MS signs and symptoms

Back 20

Unusual dexterity, numbness, tingling, memory issues, double vision, loss of balance and poor coordination, shaking tremor and muscle weakness, difficulty speaking clearly, bladder dysfunction

Front 21

MS characteristics

Back 21

Northwestern US has a high propensity for MS---may be viral, familial or environmentally related. The peak incidence is between ages 20-40 with a strong predominance in women. It is characterized by multiple relapses and remissions. It has been shown that there are increased periods of exacerbation with increased animal fat intake.

Front 22

Radiographic Appearance of MS

Back 22

MRI is used to demonstrate the scattered plaques of demyelination that are characteristic of MS. The areas of concern involve the white matter, cerebellum, brainstem and spinal cord. Appear as multiple areas of signal intensity.

Front 23

MS Treatment

Back 23

Treat with diet adjustments, medications to diminish muscle spasms, anti-inflammatories. Treatments only aid in slowing the progression of the disease; there is no cure.

Front 24

Epilepsy

Back 24

A condition in which brain impulses are temporarily disturbed, resulting in a spectrum of symptoms ranging from loss of consciousness for a few seconds to violent seizures. It is caused by uncontrolled electrical discharges from nerve cells in the cerebral cortex.

Front 25

Types of seizures

Back 25

Petit mal: mildest type, results in brief loss of consciousness, which may be associated with mild muscular twitching
Grand mal: tonic/clonic (stiff and uncontrolled muscle movements), generalized convulsions with the patient falling to the floor, hypersalivating and losing control of urine and/or feces.
Nocturnal: sudden awakening out of a deep sleep

Front 26

Possible causes of seizures

Back 26

-most are idiopathic
-trauma
-infection (high fevers)
-chemical imbalance
-tumors
-suddenly awakened
-nervousness
-fatigue

Front 27

Appearance of Epilespy on imaging studies

Back 27

MRI scan is done to search for an unsuspected brain tumor, arteriovenous malformations or hippocampal sclerosis. CT may also be used to look for the cause. However, both exams typically show normal anatomy. PET may be used to localize the seizure focus.

Front 28

Normal aging

Back 28

During normal aging, a gradual loss of neurons results in enlargement of the ventricular system and sulci.

Front 29

Alzheimer's Disease (AD)

Back 29

This is a diffuse form of progressive cerebral atrophy that develops at an earlier age than the senile period. It is a disease of progressive mental deterioration. Early onset (30's) involves chromosomes 14 and 21, while late onset (>age 70) involves chromosome 19.

Front 30

Causes of AD

Back 30

Part of DNA--genetic predisposition
Idiopathic
Autoimmune

Front 31

Symptoms of AD

Back 31

Involves failure in 3 of the following areas:
-memory (short term)
-use of language
-visuospatial skills (ie depth perception)
-changes in personality
-difficulty with simple calculations

Front 32

Radiographic appearance of AD

Back 32

CT and MRI show symmetrically enlarged ventricles with prominence of the cortical sulci. May visualize cerebral atrophy, hardening of small cerebral vessels and cortical plaques.

Front 33

Treatment of AD

Back 33

Mostly palliative treatment in an effort to retain function. Experimental drugs may be used to slow down the progression. Progression occurs faster after the age of 70. Death typically occurs 8-12 years following the onset of symptoms.

Front 34

Huntington's Disease

Back 34

This is an inherited disease that predominantly involves men and appears in the early to middle adult years. This is the deterioration of the basal ganglia causing a disconnect between the thalamus and the cerebral cortex.

Front 35

Causes of Huntington's Disease

Back 35

Possibly genetic
Idiopathic

Front 36

Signs and Symptoms of Huntington's Disease

Back 36

Characterized by dementia and rapid, jerky continuous movements (choreiform movements). These movements are NOT affected by voluntary movements. Memory loss, delusions, loss of judgment, and suicidal tendencies.

Front 37

Radiographic appearance of Huntington's

Back 37

Best seen on MRI; may visualize atrophy of Caudate nucleus and Putamen, dilation of the anterior horns of the lateral ventricles and the cerebral sulci.

Front 38

Treatment for Huntington's Disease

Back 38

Palliative trying to control the use of body functions for as long as possible, controlling the muscle spasms.
There is no cure; death typically occurs within 15 years of onset, usually from complications such as pna and heart failure.

Front 39

Parkinson's Disease

Back 39

A progressive degenerative neurologic disease in which there is a decreased amount of dopamine produced in the mid-brain. It involves the deterioration of the substantia nigra which is responsible for the release of dopamine. May also involve excessive amounts of acetylcholine in the system.

Front 40

Causes of Parkinson's Disease

Back 40

-Hereditary
-Acute encephalitis
-Metallic poisoning
-Carbon monoxide poisoning
-Pesticides and herbicides
-Anti-psychotic drugs (lithium)
-Anti-convulsant meds

Front 41

Symptoms of Parkinson's Disease

Back 41

Shuffled gait, difficulty initiating movement, tremors that can be controlled with voluntary movement, lack of facial expressions, stooped posture (cognition is NOT effected)

Front 42

Radiographic Appearance of Parkinson's Disease

Back 42

Demonstration of cortical atrophy on CT. May visualize deterioration of basal ganglia. SPECT and PET are the most useful imaging modalities to demonstrate degenerative changes. Must have clinical manifestation for proper diagnosis.

Front 43

Treatment of Parkinson's Disease

Back 43

Palliative
Drug Therapy: correct the dopamine imbalance, Levodopa (dopamine replacement)
May use electrodes to stimulate the midbrain to produce dopamine
May also do a transplant with dopamine producing tissues

Front 44

Hydrocephalus

Back 44

This is the dilatation of the ventricular system that is usually associated with increased intracranial pressure. Parkinson's and Huntington's can lead to hydrocephalus. CT shows the dilatation while MRI is useful in recognizing the cause of the obstruction.

Front 45

Treatment for Hydrocephalus

Back 45

VP shunt--ventricular peritoneal shunt; allows drainage of CSF into the peritoneal cavity to be picked up by the lymphatic system. Least invasive measure, releases pressure on the brain.
VA shunt--ventricular atrial shunt; allows drainage of CSF into the right atrium. Used if there are problems with the VP shunt. May cause increased BP and infection.
**X-rays are used to ensure the proper placement of the shunts**