Week 9: Neurological Disorders Flashcards
1
Q
What is Alzheimer’s Disease?
A
A progressive degenerative disorder of the cerebral cortex that accounts for more than one-half of all cases of dementia.
2
Q
What areas of the brain are affected by Alzheimer’s Disease?
A
Cortical degeneration is most marked in the frontal lobes, but atrophy occurs in all areas of the cortex.
3
Q
What is the prognosis for Alzheimer’s Disease?
A
It is a primary progressive dementia with poor prognosis; most patients die 2 to 20 years after the onset of symptoms, with an average duration of 8 years before death.
4
Q
What are the two forms of Alzheimer’s Disease?
A
Familial and Sporadic.
5
Q
What characterizes Familial Alzheimer’s Disease?
A
Genes directly cause the disease; it is very rare and has been identified in a relatively small number of families, with many people in multiple generations affected.
6
Q
What characterizes Sporadic Alzheimer’s Disease?
A
It is the most common form of the disease; genes don’t cause the disease but may influence the risk of developing it.
7
Q
What are the four factors thought to contribute to Alzheimer’s Disease?
A
Neurochemical factors, Viral factors, Trauma, Genetic factors.
8
Q
What are the distinguishing features of brain tissue in Alzheimer’s patients?
A
Neurofibrillary tangles, Beta-amyloid plaques, Granulovacuolar degeneration of neurons.
9
Q
What early cerebral changes occur in Alzheimer’s Disease?
A
Formation of microscopic plaques and significant atrophy of the cerebral cortex.
10
Q
How does the presence of beta-amyloid plaques affect dementia severity?
A
A large number of beta-amyloid plaques results in severe dementia; amyloid may exert neurotoxic effects.
11
Q
What neurotransmitter is primarily affected in Alzheimer’s Disease?
A
Acetylcholine; severity of dementia is directly related to its reduction.
12
Q
What are some complications associated with Alzheimer’s Disease?
A
Injury from violent behavior, pneumonia, malnutrition, dehydration, and aspiration.
13
Q
What are the initial signs and symptoms of Alzheimer’s Disease?
A
Forgetfulness, subtle memory loss, difficulty learning new information, inability to concentrate, and deterioration in personal hygiene.
14
Q
What symptoms indicate progression of Alzheimer’s Disease?
A
Difficulty with abstract thinking, progressive communication difficulties, severe memory deterioration, repetitive actions, and mood swings.
15
Q
How is patient history typically obtained in Alzheimer’s cases?
A
Almost always obtained from a family member or caregiver.
16
Q
What is Amyotrophic Lateral Sclerosis (ALS)?
A
The most common of motor neuron diseases causing muscular atrophy.
17
Q
What is the typical onset age for ALS?
A
Onset occurs between ages 40 and 70.
18
Q
How is ALS characterized?
A
A chronic, progressively debilitating disease that is rapidly fatal.
19
Q
What are possible causes of ALS?
A
Possible causes include a slow-acting virus, nutritional deficiency related to enzyme metabolism, metabolic interference in nucleic acid production by nerve fibers, and autoimmune disorders affecting immune complexes.
20
Q
What happens to nerve cells in ALS?
A
Nerve cells that control the muscles, known as motor neurons, are destroyed.
21
Q
Where are motor neurons located?
A
Motor neurons are located in the anterior gray horns of the spinal column and the motor nuclei of the lower brain stem.
22
Q
What occurs as motor neurons die in ALS?
A
The muscle fibers that they supply atrophy.
23
Q
What types of motor neurons may be affected in ALS?
A
Loss of motor neurons may occur in both the upper and lower motor neuron systems.
24
Q
What is the primary sign of ALS?
A
Muscle weakness, seen in 60% of affected patients.
25
What are some other signs and symptoms of ALS?
Other signs include fasciculations, impaired speech, difficulty chewing and swallowing, difficulty breathing, choking, excessive drooling, depression, and inappropriate laughing or crying spells.
26
What is epilepsy?
Epilepsy is a seizure disorder characterized by recurrent seizures.
27
What are seizures?
Seizures are paroxysmal events associated with abnormal electrical discharges of neurons in the brain.
28
What symptoms can seizures trigger?
Seizures may trigger convulsive movements, interruptions of sensation, alterations in level of consciousness (LOC), or a combination of these symptoms.
29
Does epilepsy affect intelligence?
In most patients, epilepsy doesn’t affect intelligence.
30
Who can be affected by epilepsy?
Epilepsy affects people of all ages, races, and ethnic backgrounds.
31
When does epilepsy most commonly appear?
Epilepsy most commonly appears in early childhood.
32
What percentage of epilepsy cases are idiopathic?
About 50% of epilepsy cases are idiopathic (spontaneous with an unknown cause).
33
What are some possible causes of epilepsy?
Possible causes include genetic abnormalities, hereditary abnormalities, phenylketonuria, perinatal injuries, metabolic abnormalities, brain tumors, infections, traumatic injury, and ingestion of toxins.
34
What is the pathophysiology of epilepsy?
A group of neurons may lose the ability to transmit impulses and function as an epileptogenic focus, becoming hypersensitive and easily activated.
35
What physical findings may be present in epilepsy?
Physical findings may be normal if the patient doesn’t have a seizure during assessment and the cause is idiopathic.
36
How are seizures related to a patient's history?
If a seizure is caused by an underlying problem, the patient’s history and physical examination should uncover related signs and symptoms.
37
Are seizures predictable?
In many cases, seizures are unpredictable and unrelated to activities, though some patients may report precipitating factors.
38
What are nonspecific symptoms of epilepsy?
Nonspecific symptoms include headache, mood changes, lethargy, and myoclonic jerking before onset.
39
What is an aura in relation to seizures?
An aura is a sensation that occurs a few seconds or minutes before a generalized seizure, signaling the beginning of abnormal electrical discharges.
40
What are typical auras experienced by patients?
Typical auras include a pungent smell, nausea, a rising or sinking feeling in the stomach, a dreamy feeling, unusual taste, and visual disturbances such as flashing lights.
41
What is Guillain-Barré Syndrome (GBS)?
An acute, autoimmune, rapidly progressive, potentially fatal syndrome.
42
What is associated with Guillain-Barré Syndrome?
Segmented demyelination of peripheral nerves.
43
What is another name for Guillain-Barré Syndrome?
Acute demyelinating polyneuropathy.
44
What is the typical age range for the occurrence of GBS?
Usually occurring between ages 30 and 50.
45
How common is Guillain-Barré Syndrome?
Affects about 1 out of every 100,000 people.
46
What percentage of GBS patients recover with few or no residual symptoms?
80% to 90% of patients.
47
What is the precise cause of GBS?
Unknown, but thought to be a cell-mediated, immunologic attack on peripheral nerves in response to a virus.
48
What are some risk factors for GBS?
Surgery, rabies or swine influenza vaccination, viral illness, Hodgkin’s disease or another malignant disease, lupus erythematosus.
49
What is the pathophysiology of GBS?
Immunologic reaction causes segmental demyelination of the peripheral nerves, preventing normal transmission of electrical impulses.
50
What happens to the myelin sheath in GBS?
It degenerates probably due to an autoimmune mechanism.
51
What are the signs and symptoms of GBS?
Tingling and numbness, muscle weakness, immobility, paralysis, muscle stiffness and pain, sensory loss, loss of position sense, and diminished or absent deep tendon reflexes.
52
How do symptoms of GBS usually progress?
Symptoms usually follow an ascending pattern, beginning in the legs and progressing to the arms, trunk, and face.
53
In mild forms of GBS, what may be affected?
Only cranial nerves may be affected.
54
Can muscle weakness be absent in some patients with GBS?
Yes, in some patients, muscle weakness may be absent.
55
What is meningitis?
Meningitis is an infection of the membranes surrounding the brain and spinal cord.
56
What are the major causes of bacterial meningitis?
The majority of bacterial meningitis infections are caused by Streptococcus pneumoniae (gram-positive) or Neisseria meningitides (gram-negative).
57
Where do the bacteria causing meningitis usually reside?
These bacteria usually reside in the nasopharyngeal region.
58
How do bacteria gain access to the bloodstream?
They gain access to the bloodstream by disabling cilia and the mucosal IgA-mediated immune protection in the nasopharyngeal region.
59
Why are capsulated bacterial species harder for the immune system to recognize?
These are capsulated bacterial species, hence harder for the immune system to recognize them.
60
What type of immune response do these bacteria provoke?
They provoke a weak complement response.
61
What happens when bacteria cross the blood-brain barrier?
They cross the blood-brain barrier and colonize tissue.
62
How does damage to CNS structures occur in meningitis?
Damage to CNS structures is mediated by the release of bacterial toxins.
63
What role does inflammation play in meningitis?
The resultant inflammatory response also makes a significant secondary contribution to injury.
64
What does inflammation induce in meningitis?
Inflammation induces a vascular response that leads to cerebral edema.
65
What are the consequences of cerebral edema?
Edema causes a rise in intracranial pressure and can cause compression, herniation, and ischemia.
66
What are the risk factors for poor outcomes in bacterial meningitis?
Risk factors include advanced age, presence of osteitis/sinusitis, low GCS score on admission, tachycardia, positive blood culture, ↑ ESR, thrombocytopenia, and ↓ CSF WBC count.
67
What is viral meningitis?
Viral meningitis is milder, short-lived, and self-limiting.
68
What is the recovery outlook for viral meningitis?
Affected persons recover completely from viral meningitis.
69
When are most cases of viral meningitis seen?
Most cases are seen in summer and may be associated with swimming.
70
What are some causative organisms of viral meningitis?
Causative organisms include enteroviruses, herpes simplex virus, cytomegalovirus (CMV), adenoviruses, HIV, and arboviruses.
71
What is the classic triad of clinical manifestations of bacterial meningitis?
The classic triad includes fever, nuchal rigidity (stiff neck), and altered mental state.
72
What are other manifestations of bacterial meningitis?
Other manifestations include headache, photophobia, lethargy, vomiting, petechial rash, and seizures.
73
What are the complications of bacterial meningitis?
Complications include circulatory shock, coma, seizures, and death.
74
What is encephalitis?
Predominantly a viral infection.
75
What are some causative viruses of encephalitis?
Herpes simplex virus, Herpes zoster virus, Rabies, Epstein-Barr virus, CMV, Enteroviruses, Arboviruses.
76
What are some examples of arboviruses associated with encephalitis?
Mostly mosquito-borne viruses such as West Nile virus, Eastern and Western equine virus, and flavivirus.
77
What other pathogens can cause encephalitis?
Some bacteria and the parasite Toxoplasma gondii.
78
How do viruses gain access to the CNS in encephalitis?
Via the bloodstream, by direct entry from neighbouring structures, or retroaxonally from peripheral nerve endings.
79
What are common clinical manifestations of encephalitis?
Fever, altered level of consciousness, cerebral dysfunction (e.g., memory loss, cognitive deficits, changes in personality, and hallucinations).
80
What are brain abscesses?
Brain abscesses are purulent infections that develop focally at either epidural or subdural locations.
81
What can cause a brain abscess?
Various bacteria including anaerobes, certain parasites, and fungi can cause a brain abscess.
82
What are common clinical features of brain abscesses?
Neurological manifestations common and dependent on the location of the abscess with respect to the brain region affected: motor impairment, aphasia.
83
What signs may indicate increased intracranial pressure in brain abscesses?
Signs of increased intracranial pressure may develop—papilloedema (optic disc swelling).
84
What other symptoms may be present with brain abscesses?
Fever and seizures.
85
What is Multiple Sclerosis (MS)?
MS results from progressive demyelination of the white matter of the brain and spinal cord, leading to widespread neurological dysfunction.
86
Which structures are usually involved in MS?
The optic and oculomotor nerves and the spinal nerve tracts.
87
Does MS affect the peripheral nervous system (PNS)?
No, it does not affect the PNS.
88
What characterizes the course of MS?
It is characterized by exacerbations and remissions.
89
What is a major demographic affected by MS?
It is a major cause of chronic disability in people between ages 18 and 40.
90
Who has the highest incidence of MS?
Incidence is highest in women, in northern urban areas, in higher socioeconomic groups, and in people with a family history of the disease.
91
What is the exact cause of MS?
The exact cause is unknown.
92
What are some possible causes of MS?
May be caused by a slow-acting viral infection, an autoimmune response, or an allergic response. Other possible causes include trauma, anoxia, toxins, nutritional deficiencies, vascular lesions, and anorexia nervosa.
93
What factors may precede the onset of MS?
Emotional stress, overwork, fatigue, pregnancy, or an acute respiratory tract infection.
94
Do genetic factors play a role in MS?
Yes, genetic factors may also play a part.
95
How does MS affect the white matter of the brain and spinal cord?
It causes scattered demyelinated lesions that prevent normal neurologic conduction.
96
What happens after the myelin is destroyed in MS?
Neuroglial tissue in the white matter of the CNS proliferates (gliosis), forming hard yellow plaques of scar tissue.
97
What results from the disruption of nerve conduction in MS?
It results in disruption of nerve conduction.
98
What is the probable origin of demyelination in MS?
The process of demyelination probably is of autoimmune origin.
99
What can destroy myelin in MS?
Cytotoxic T cells directly and/or autoantibody against myelin can destroy myelin.
100
What are initial symptoms of MS?
Initial symptoms include vision problems (optic neuritis) and sensory impairment (paraesthesia).
101
What are later symptoms of MS?
Later symptoms include blurred vision or diplopia, emotional lability, and dysphagia.
102
What are other signs and symptoms of MS?
Other signs and symptoms include poorly articulated speech, muscle weakness and spasticity, hyperreflexia, urinary problems, intention tremor, gait ataxia, bowel problems, cognitive dysfunction, fatigue, and paralysis.
103
What is Myasthenia Gravis (MG)?
MG is a disease of sporadic, progressive weakness and abnormal fatigue of voluntary skeletal muscles.
104
What exacerbates the effects of Myasthenia Gravis?
The effects are exacerbated by exercise and repeated movement.
105
Which muscles are usually affected by Myasthenia Gravis?
It usually affects muscles in the face, lips, tongue, neck, and throat, but it can affect any muscle group.
106
What can happen to muscle fibers in advanced Myasthenia Gravis?
Muscle fibers may degenerate, and weakness may become irreversible.
107
What is a potential life-threatening complication of Myasthenia Gravis?
When the disease involves the respiratory system, it may be life-threatening.
108
What type of disorder is Myasthenia Gravis?
MG is an autoimmune disorder.
109
What causes Myasthenia Gravis?
It is caused by an antibody-mediated blockade of neuromuscular transmission resulting in skeletal muscle weakness.
110
What occurs during the autoimmune attack in Myasthenia Gravis?
Autoantibodies form against the nicotinic acetylcholine postsynaptic receptors at the neuromuscular junction.
111
What are common signs and symptoms of Myasthenia Gravis?
Common signs and symptoms include extreme muscle weakness, fatigue, ptosis, diplopia, difficulty chewing and swallowing, sleepy expression, drooping jaw, bobbing head, and arm or hand muscle weakness.
112
What is Parkinson’s Disease (PD)?
PD is a common idiopathic neurodegenerative disorder that primarily causes motor impairment and involves changes in sensory, cognitive, and emotional processing.
113
What are the risk factors for Parkinson’s Disease?
Risk factors include older age, males, and inheritance.
114
What is the primary pathophysiology of Parkinson’s Disease?
The primary pathophysiology includes degeneration of the dopaminergic nigrostriatal pathway in the brain.
115
What occurs due to dopamine deficiency in Parkinson’s Disease?
A dopamine deficiency occurs in the basal ganglia, upsetting the balance between inhibitory dopamine and excitatory acetylcholine neurotransmitters.
116
What are the main signs and symptoms of Parkinson’s Disease?
Main signs and symptoms include tremor at rest (pill-rolling), rigidity (cogwheel), akinesia or bradykinesia, and postural instability.
117
What are some other common features of Parkinson’s Disease?
Other common features include flexed posture, freezing, loss of facial expression, impaired swallowing, dystonia, decreased arm swinging, shuffling gait, and small handwriting.
118
What are the non-motor symptoms of Parkinson’s Disease?
Non-motor symptoms include autonomic dysfunction, sleep disorders, sensory dysfunction, and cognitive and behavioral abnormalities.
119
What is a stroke?
A stroke, or CVA (Cerebrovascular Accident), is a sudden impairment of cerebral circulation in one or more of the blood vessels supplying the brain.
120
What are the consequences of a stroke?
It interrupts or diminishes oxygen supply, causing serious damage or necrosis in brain tissues.
121
What is the importance of timely treatment for a stroke?
The sooner circulation returns to normal after a stroke, the better the chances are for complete recovery.
122
What percentage of stroke survivors remain permanently disabled?
About one-half of those who survive remain permanently disabled and may suffer another stroke within weeks, months, or years.
123
What is the rank of stroke as a cause of death?
Stroke is the third most common cause of death.
124
Can stroke affect people of all ages?
Yes, stroke can strike people of any age.
125
Which demographic has a higher risk of stroke?
Black men have a higher risk of stroke.
126
Is stroke more common in men or women?
Stroke is more common in women than in men.
127
How is stroke classified?
Stroke is classified according to how it progresses.
128
What is a Transient Ischaemic Attack (TIA)?
TIA, the least severe type of stroke, is caused by a temporary interruption of blood flow, usually in the carotid and vertebrobasilar arteries.
129
What is a progressive stroke?
A progressive stroke, also called stroke-in-evolution, begins with a slight neurological deficit and worsens in a day or two.
130
What is a completed stroke?
A completed stroke, the most severe type, causes maximum neurological deficits at the onset.
131
What are some risk factors for stroke?
Risk factors include hypertension, history of TIA, high serum triglyceride levels, atherosclerosis, atrial fibrillation, and more.
132
What are the three major causes of stroke?
The three major causes are thrombosis, embolism, and haemorrhage.
133
What happens during thrombosis?
Thrombosis causes congestion and oedema in the affected vessel as well as ischaemia in the brain tissue supplied by the vessel.
134
What occurs during embolism?
Embolism cuts off circulation in the cerebral vasculature by lodging in a narrow portion of the artery, causing necrosis and oedema.
135
What is haemorrhage in the context of stroke?
Haemorrhage occurs when a brain artery bursts, diminishing blood supply to the area served by the artery.
136
What factors determine the signs and symptoms of a stroke?
Physical findings depend on the artery affected, the portion of the brain it supplies, severity of the damage, and extent of collateral circulation.
137
What are some common signs of stroke?
Common signs include sudden numbness or weakness, confusion, trouble seeing, trouble walking, and severe headache.
138
What does sudden numbness or weakness indicate?
Sudden numbness or weakness of face, arm, or leg, especially on one side of the body, is a sign of stroke.
139
What does sudden confusion or trouble speaking indicate?
Sudden confusion, trouble speaking, or understanding speech is a sign of stroke.
140
What does sudden trouble seeing indicate?
Sudden trouble seeing in one or both eyes is a sign of stroke.
141
What does sudden trouble walking indicate?
Sudden trouble walking, dizziness, loss of balance or coordination is a sign of stroke.
142
What does a sudden severe headache indicate?
A sudden severe headache with no known cause is a sign of stroke.
