Other disorders of the nervous system Flashcards
Huntington’s Chorea
- UMN issue
- dominantly inherited disease of the basal ganglia and cerebral cortex
- characterized by development in adult life (most often between ages 30 and 40 y/o. Because of late onset many have had children by that time)
- choreiform movements and progressive mental deterioration and dementia occur (usually see the abrupt and jerky choreiform movements of the face, tongue, arms, hands, legs, and trunks)
- CT scan: demonstrates cerebral atrophy, enlargement of ventricles, and characteristic “butterfly” appearance of the lateral ventricles due to atrophy of the caudate nucleus.
- duration of life varies- average 5-20 years post diagnosis
- because of dread of disease in many families, alcoholism, psychiatric disease, and suicide are common- even among unaffected members
- as disease continues, institutional care is almost always necessary
Amyotrophic lateral sclerosis (Lou Gehrig’s disease)
•both UMN and LMN disease
•disease of unknown etiology, which is chronic, progressive, and degenerative. More common in males
selectively attacks the (1) corticospinal tracts in the lateral white columns, and (2) motor neuron cell bodies in the ventral gray anterior horn cells. This gives a combination of UMN and LMN signs.
• usually begins midcord level- see characteristic triad of: muscle weakness, muscle atrophy, and hyperreflexia in the hand- forearm and later shoulder girdle without pain or other sensory disturbances
•also see fasiculations in the limbs, hyperactive reflexes, and Babinski signs
•with time disease progresses upwards and involves brain stem but spares intellect and sensations
•there is no known cure and death usually occurs 3-5 years post symptoms appearing
•TX: maintain function, and then comfort for as long as possible
Guillian-barre (or acute inflammatory polyneuropathy
- LMN issue
- an acute, rapidly progressive form of polyneuropathy which usually begins after an infectious disorder (usually viral upper repiratory or alimentary tracts), immunization, or surgery
- distal muscles usually involved first, and the disease normally spreads centrally. Without fasiculations, but with areflexia (DTR 0 or 1). Mild sensory impairment (one of the first signs may be parasthesias, numbness). May also see ataxia.
- weakness is nearly always bilateral and may progress to any degree of severity even up to quadriparesis with respiratory failure
- CSF protein tends to rise as disease progresses
- patients who begin to recover in the first two weeks post onset usually do so completely. Recovery period may last for over a year- but over 1/2 patients better by 1/2-3/4 year. Continuous weakness, malaise, and easy fatiguability trouble the remainder.
- TX: paralysis= PROM. As it improves progress to active. Increase postural tone: stability, controlled mobility, coordinated skill.
Myasthenia Gravis
•LMN disease
•an autoimmune disease affecting the neuromuscular junction (antibodies are produced by the body against acetylcholine receptors of the muscle end plate)
•characterized by progressive muscular weakness during activity. First contraction of the muscle is forceful but the next few contractions rapidly decrease in power- strength returns after the patient rests.
•especially seen in the muscles of the eyelid, face, jaw and limbs, leading to: ptosis (drooping eyelid), drooping jaw, dysphagia, and dysphonia
TX: prolonging life of acetylcholine by neuromuscular blocking agents i.e. curare- poison that blocks neuromuscular transmission; anti-cholinesterase therapy
Viral infections: encephalitis
- inflammation and infection of brain tissue by any one of a large number of viruses
- clinical features include fever and meningism (headache, neck stiffness, and photophobia), signs of of raised intracranial pressure, reduction in conscious level from drowsiness to coma, seizures which are focal and other focal signs depending on area of the brain involved in the inflammatory process
- TX: general measures- maintain hydration, metabolic status, reduce fever, prevent seizures
Poliomyelitis
- viral infection of the anterior horn cells causing classic LMN signs
- there are 3 types: Type I- most common. Spread by fecal contamination from person to person. In developed countries it has been eliminated by vaccine developed by Salk, Sabin, and Enders
- clinical picture: focal encephalitis of the SC or the brainstem may progress to severe muscle pain, meningism (headache, neck stiffness, and photophobia), delerium and sudden appearance of asymmetrical or generalized paralysis. The muscles are tender and fasiculations may be seen and felt in the earliest stages. This stage is usually over in a week with some degree of improvement. May have severe respiratory paralysis requiring artificial ventilation and skilled nursing attention. Sister Kenney developed a program of exercise for these patients
Post-polio sequelae/syndrome
• many polio survivors (1/4-1/3) are now experiencing new symptoms- such as unaccustomed fatigue, joint and muscle pain, intolerance to cold, and respiratory problems.
TX: teach ways to prevent secondary disabilities and preserve muscle strength. Frequent rest periods. Energy conservation techniques. Losing excessive weight. Stop smoking.
Herpes Zoster (shingles)
- LMN issue
- patient may have history of chicken pox (virus for the 2 is the same) after many years of latency- may be activated by unknown mechanism.
- primarily affects dorsal root ganglion cells of spinal nerves and sensory ganglia of cranial nerves
- at spinal level, involvement usually unilateral and 75% occur in abdominal and upper thoracic regions. Virus will occasionally attack anterior horn cells
- clinical picture: burning/shooting pain, local hyperalgesia within affected dermatomes followed in 3-4 days
- motor involvement may affect face, eye, diaphragm, or limb musculature
- CONTAGIOUS
AIDS:
•virus weakens and destroys T4 lymphocytes- the bodies defense mechanism- making brain susceptible to lethal yeasts, molds, fungi- that have no therapy. Virus also directly attacks and destroys the neurons and white matter of the brain- gives MS symptoms.
Meningitis
- can be both viral and bacterial
- infection of the cerebral and/or spinal meninges (usually arachnoid or pia matter) 80-90% of cases caused by bacteria
- always a neurological emergency
- Triad of: fever, HA, stiff neck- should alert health care worker as possibility of disease. Spinal tap, lumbar puncture, is done at once and cultured, antibiotics initiated
- TX: bacterial: antibiotics. Viral: antiviral and suportive therapy
Tetanus
- occurs when a cut or wound is invaded by clostridium tetani. Once in tissue the bacteria produces a powerful neurotoxin that causes severe muscular spasms
- trismus (lockjaw), dysphagia are common. Opisthotonos (stiff extension posturing) positioning may be present.
Lyme disease
- spirochete infection transmitted by the bite of a deer tick. Red rash follows bite around area and mild flu like symptoms that disappear
- 2-3 months later- arthritis of the joints (it likes the knees) along with various neurological symptoms- i.e. bilateral Bell’s palsy
Brain tumor types
- meningioma
- astrocytoma
- glioblastoma
Syphilis
- caused by spirochete. Last or tertiary stage occurs many years post infection and may affect nervous system causing many symptoms- including mental- delusions of grandeur
- see Tabes Dorsalis (dorsal columns are affected= conscious proprioception): type of syphilis- degenerative changes in posterior roots and posterior root entry zone secondary to degeneration in dorsal columns. Decreased proprioception, slapping “Tabetic” gait (characteristic ataxic gait of untreated syphilis where the person’s feet slap the ground as they strike the floor due to loss of proprioception) , progressive ataxia, positive Romberg’s test may be seen.
Meningioma
- tumors of the covering of the brain.
- common
- often can be totally excised and rarely metastasize
- increased intracranial pressure -> symptoms: papilledema (a serious medical condition where the optic nerve at the back of the eye becomes swollen. Symptoms can include visual disturbances, headaches, and nausea) , nausea, vomitting, headaches
