Nervous System Flashcards

Question

``` Which of the following is NOT a risk factor for a CVA? Arterial hypertension Smoking Diabetes Obesity ```

Answer 1

Obesity ------------ Obesity may indirectly cause other risk factors but is not a direct risk factor. The other risk factors include arterial hypertension, smoking, diabetes, insulin resistance, polycythemia, increased lipoprotein A, impaired cardiac function, hyperhomocysteinemia, and atrial fibrillation.

Answer 2

The most common cause of hemorrhagic stroke is hypertension. -------- Hemorrhagic stroke is the third most common cause of CVA. It accounts for 10% of strokes. The most common cause is hypertension. Hemorrhages can be massive, small, slit, or petechial. An infarct is a type of occlusive stroke.

Answer 3

Heroin abuse ------------- Aneurysm formation has been linked to cocaine use.

Answer 4

Can be due to a combination of congenital and degenerative changes ------------ Saccular aneurysms can be due to a combination of congenital and degenerative changes. They affect approximately 2% of the general population. They grow slowly over time and are rare in childhood.

Answer 5

Individuals with intracranial aneurysm are at risk. ------------ Individuals with intracranial aneurysms are at risk for subarachnoid hemorrhage. Hypertension and trauma are also risk factors. The mortality rate is more than 50%.

Answer 6

Migraine without aura.

Answer 7

Migraines occur most frequently before and during menses. ------------ Migraines occur most frequently during menses and right before menses. They often decrease with menopause and pregnancy. The diagnosis is made from medical history and physical examination. They are linked to depression. Drug therapy includes anti-inflammatory medications, ergotamine, magnesium, and the triptans. Narcotics may be used but are not routine.

Answer 8

Tension headache ------------ A tension headache often feels like a band is constricting the head. Migraines tend to throb and are often unilateral. Cluster headaches are more common in men; several can occur in a day and are often unilateral.

Answer 9

Astrocytoma ------------ Astrocytomas are the most common brain tumors and account for 50% of brain and spinal tumors. Oligodendrogliomas are less commonly occurring gliomas. Ependymomas are gliomas that arise from ependymal cells. Meningiomas account for about 20% of all intracranial tumors.

Answer 10

Grades III and IV are treated with surgery. ------------ Grade I is treated with surgery and then follow-up CT scans for recurrence. Grade II is treated surgically if accessible and then followed with radiation. Grades III and IV are treated with surgery. Grade III is well circumscribed.

Answer 11

They are commonly found in the frontal lobe and cerebral hemisphere. ------------ Astrocytomas are commonly found in the frontal lobe and cerebral hemisphere. They are found twice as often in men as in women. They are often large and well circumscribed with a variegated pattern. The rim is pinkish gray and solid with a soft, yellow, necrotic center. There is vascular proliferation.

Answer 12

Cysts and calcifications present ----------------------- Oligodendrogliomas are slow-growing, well-differentiated tumors that often have cysts and calcifications. They comprise 2% of all brain tumors.

Answer 13

Parasellar ------------ The parasellar area demonstrates evidence of chiasmatic compression, urinary incontinence, dementia, gradual paraparesis, hormonal failure, optic atrophy, and bitemporal hemianopia. Involvement of the sphenoidal wing results in ophthalmoplegia and mild proptosis. The olfactory groove will demonstrate anosmia, personality change, and visual failure. A parasagittal site demonstrates focal seizures.

Answer 14

Carcinomas are disseminated to the brain from the circulation. ------------ Carcinomas disseminate to the brain from the circulation. Two thirds of metastatic tumors are located within the brain, and one third are located in the extradural spaces. Tumors of the pelvis tend to metastasize to the cerebellum and pons.

Answer 15

Tubercular meningitis has a 90% recovery rate with an early diagnosis. ----------------- Tubercular meningitis has a 90% recovery rate with an early diagnosis and treatment. Fungal meningitis is uncommon. Aseptic meningitis is most commonly caused by a virus. Bacterial meningitis is caused by primary infection of the pia mater and arachnoid.

Answer 16

Cranial nerve VII ------------ Cranial nerve VII is responsible for innervating the muscles of facial expression. Cranial nerve II causes papilledema and blindness. Cranial nerves III, IV, and VI cause ptosis, visual field defects, and diplopia. Cranial nerve VIII causes deafness, tinnitus, and vertigo.

Answer 17

Early capsule formation --------------- Early capsule formation occurs on days 10 to 13. The necrotic center decreases in size; inflammatory infiltrate changes in character. Mature collagen evolves, forming a capsule. Early cerebritis occurs on days 1 to 3 and is a localized inflammatory process. There is marked cerebral edema and a central core of necrosis. Late cerebritis occurs on days 4 to 9, and there is a necrotic center surrounded by inflammatory infiltrate of macrophages and fibroblasts. There is rapid new blood vessel formation. Late capsule formation occurs on day 14 and later. There is a well-formed necrotic center surrounded by a dense collagenous capsule.

Answer 18

It is caused by arthropod-borne viruses. ------------ It is caused by a virus, often arthropod (tick or mosquito) borne. Herpes simplex 1 can also cause the illness; type 1 is more common than type 2. Encephalitis is an acute febrile illness.

Answer 19

Is a demyelinating disorder ------------ It is a demyelinating disorder of the CNS and affects the peripheral nervous system. It is relatively common and affects the myelin.

Answer 20

Guillain-Barré ------------ Guillain-Barré is an idiopathic polyneuritis with acute inflammatory demyelinating characteristics. There is demyelination of the peripheral nerves with relative sparing of the axons. Alzheimer is a form of dementia caused by tangles. Myasthenia gravis is due to antiacetylcholine receptor antibodies. ALS is a degenerative disorder diffusely involving lower and upper motor neurons resulting in progressive muscle weakness.

Answer 21

A brief stroke-like attack that, despite resolving within minutes to hours, still requires immediate medical attention to distinguish from an actual stroke. TIA is caused by a clot; the only difference between a stroke and TIA is that with TIA the blockage is transient (temporary). TIA symptoms occur rapidly and last a relatively short time. Most TIAs last less than five minutes; the average is about a minute. When a TIA is over, it usually causes no permanent injury to the brain.

Answer 22

Immediate evaluation! A stroke may soon follow. Prompt medical treatment may prevent a stroke. Treatment for a TIA may include taking medicines to prevent a stroke or having surgery to reopen narrow arteries. Medicines may include aspirin, clopidogrel, dipyridamole with aspirin, or warfarin. If your carotid arteries are significantly narrowed, you may need a procedure to widen the arteries. This may prevent another TIA or a stroke.

Answer 23

The effects of TBI can be profound. Individuals with severe injuries can be left in long-term unresponsive states. For many people with severe TBI, long-term rehabilitation is often necessary to maximize function and independence. Even with mild TBI, the consequences to a person’s life can be dramatic. Change in brain function can have a dramatic impact on family, job, social and community interaction.

Answer 24

The nervous system is itself divided into two sections: The Peripheral Nervous System (PNS): sensory receptors and motor effectors The Central Nervous System (CNS): Brain and spinal cord In summary, the nervous system is organized as follows: Peripheral Nervous System (PNS) Consists of nerve cells that lie outside the brain case or spinal vertebrae. Sensory receptors detect changes in the external environment (visual, auditory, olfactory, sensory, etc.) and communicates them to the CNS (via afferent sensory nerves). The CNS, in turn, communicates desired behavior such as muscle movement to the PNS (via efferent motor nerves) using motor effectors. The PNS is divided into two sections: 1. Autonomic Division: controls smooth muscles (involuntary), such as the stomach and heart. 2. Somatic Division, which controls striated muscles (voluntary), which are the skeletal muscles. In summary, the PNS consists of: ``` Sensory (afferent nerves) Motor (efferent nerves) Somatic Division Autonomic Division The Autonomic Division can itself be divided into Sympathetic and Parasympathetic divisions: ``` Parasympathetic Maintains bodily functions such as digestion and blood flow at a balanced level Maintains homeostasis Sympathetic 'Fight-or-flight' system Diverts energy away from sustaining activities Instead, mobilizes the delivery of oxygen (via the blood) to the extremities and brain Increases responsiveness Central Nervous System (CNS) The central nervous system integrates information arriving from the PNS, processes this information to generate behavior, which it communicates back to the PNS. The CNS is divided into two sections: the spinal cord, which connects directly with the PNS, and the brain, which contains the higher brain functions. Both are encased within bone. The brain communicates its behavior to the PNS by way of the spinal cord. In cases of very quick reflexes, such as pain response, the PNS-spinal cord-PNS pathway is invoked without first processing information in the brain (e.g., knee jerk response). The brain itself consists of three major divisions: cerebral hemispheres, cerebellar hemispheres, and the brain stem.

Answer 25

CSF) is a clear, colorless, bodily fluid that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord. The CSF occupies the space between the arachnoid mater (the middle layer of the brain cover, the meninges) and the pia mater (the layer of the meninges closest to the brain). It constitutes the content of all intra-cerebral (inside the brain, the cerebrum) ventricles, cisterns, and sulci (singular sulcus), as well as the central canal of the spinal cord. It acts as a cushion or buffer for the cortex, providing a basic mechanical and immunological protection to the brain inside the skull and serves a vital function in cerebral autoregulation of cerebral blood flow. CSF Production CSF is produced in the brain by modified ependymal cells in the choroid plexus (approximately 50% to 70%) and the remainder is formed around blood vessels and along ventricular walls . It circulates from the lateral ventricles to the foramen of Monro (interventricular foramen), third ventricle, aqueduct of Sylvius (cerebral aqueduct), fourth ventricle, foramen of Magendie (median aperture) and foramina of Luschka (lateral apertures), and the subarachnoid space over the brain and the spinal cord . It should be noted that the CSF moves in a pulsatile manner throughout the CSF system with nearly zero net flow. CSF is reabsorbed into venous sinus blood via arachnoid granulations. The CSF is produced at a rate of 500 ml / day. Since the subarachnoid space around the brain and spinal cord can contain only 135 to 150 ml, large amounts are drained primarily into the blood through arachnoid granulations in the superior sagittal sinus. Thus the CSF turns over about 3.7 times a day. This continuous flow into the venous system dilutes the concentration of larger, lipid-insoluble molecules penetrating the brain and CSF. The CSF contains approximately 0.3% plasma proteins, or approximately 15 to 40 mg / dL, depending on the sampling site.

Answer 26

An upper motor neuron lesion (also known as pyramidal insufficiency) is a lesion of the neural pathway above the anterior horn cell of the spinal cord or motor nuclei of the cranial nerves. (This is in contrast to a lower motor neuron lesion, which affects nerve fibers traveling from the anterior horn of the spinal cord or the cranial motor nuclei to the relevant muscle(s).) Upper motor neuron lesions occur in conditions affecting motor neurons in the brain or spinal cord such as stroke, multiple sclerosis, traumatic brain injury and cerebral palsy.

Answer 27

A lower motor neuron lesion is a lesion which affects nerve fibers traveling from the ventral horn or anterior grey column of the spinal cord to the relevant muscle(s) – the lower motor neuron.[1] One major characteristic used to identify a lower motor neuron lesion is flaccid paralysis – paralysis accompanied by loss of muscle tone. This is in contrast to an upper motor neuron lesion, which often presents with spastic paralysis – paralysis accompanied by severe hypertonia.

Answer 28

flaccid paralysis – paralysis accompanied by loss of muscle tone. (lower motor neuron lesion)

Answer 29

spastic paralysis – paralysis accompanied by severe hypertonia. (upper motor neuron lesion)

Answer 30

1. Buoyancy: The actual mass of the human brain is about 1400 grams; however, the net weight of the brain suspended in the CSF is equivalent to a mass of 25 grams. The brain therefore exists in neutral buoyancy, which allows the brain to maintain its density without being impaired by its own weight. 2. Protection: CSF protects the brain tissue from injury when jolted or hit. 3. Chemical stability: CSF flows throughout the inner ventricular system in the brain and is absorbed back into the bloodstream, rinsing the metabolic waste from the central nervous system through the blood–brain barrier. This allows for homeostatic regulation of the distribution of neuroendocrine factors, to which slight changes can cause problems or damage to the nervous system. 4. Prevention of brain ischemia: The prevention of brain ischemia is made by decreasing the amount of CSF in the limited space inside the skull. This decreases total intracranial pressure and facilitates blood perfusion.

Answer 31

CSF as a Diagnostic Tool When CSF pressure is elevated, cerebral blood flow may be constricted. When disorders of CSF flow occur, they may therefore affect not only CSF movement but also craniospinal compliance and the intracranial blood flow, with subsequent neuronal and glial vulnerabilities. The venous system is also important in this equation. Infants and patients shunted as small children may have particularly unexpected relationships between pressure and ventricular size, possibly due in part to venous pressure dynamics. This may have significant treatment implications, but the underlying pathophysiology needs to be further explored. CSF can be tested for the diagnosis of a variety of neurological diseases. It is usually obtained by a procedure called lumbar puncture. Removal of CSF during lumbar puncture can cause a severe headache after the fluid is removed, because the brain hangs on the vessels and nerve roots, and traction on them stimulates pain fibers. The pain can be relieved by intrathecal injection of sterile isotonic saline. Lumbar puncture is performed in an attempt to count the cells in the fluid and to detect the levels of protein and glucose. These parameters alone may be extremely beneficial in the diagnosis of subarachnoid hemorrhage and central nervous system infections (such as meningitis). Moreover, a CSF culture examination may yield the microorganism that has caused the infection.

Answer 32

Mild and severe

Answer 33

* A brain injury can be classified as mild if loss of consciousness and/or confusion and disorientation is shorter than 30 minutes. * MRI and CAT scans are often normal. *cognitive problems such as headache, difficulty thinking, memory problems, attention deficits, mood swings and frustration. * These injuries are commonly overlooked. Even though this type of TBI is called “mild”, the effect on the family and the injured person can be devastating.

Answer 34

* loss of consciousness for more than 30 minutes and memory loss after the injury or penetrating skull injury longer than 24 hours. *deficits range from impairment of higher level cognitive functions to comatose states. * may have limited function of arms or legs, abnormal speech or language, loss of thinking ability or emotional problems. * The range of injuries and degree of recovery is very variable and varies on an individual basis.