Archive | February 2011

Neuropathies

Diseases affecting the nerves.

Diseases affecting the motor or sensory peripheral nerves are categorized as neuropathies.

Manifestations:

  1. muscular weakness and wasting
  2. anesthesias
  3. paresthesias
  4. clumsiness

Types of neuropathies:

  1. Motor neuropathies
  2. Sensory neuropathies
  3. Mixed (motor and sensory) neuropathies

Categories depending on nerve involvement:

  1. Mononeuropathies
  2. Polyneruopathies

Mononeuropathies:

  • involve a single peripheral nerve
  • involvement of several discrete nerves is referred to as mononeuritis multiplex
  • Mononeuropathies are usually caused by local trauma, ischemia, infiltration or vascular disease

Polyneuropathies:

  • Describes diffuse involvement of peripheral nerves
  • Polyneuropathies are usually caused by diseases which involve the nerves diffusely.

Beneficial properties of Lysine

Lysine is an essential amino acid.

It cannot be manufactured in the body and must be obtained from dietary sources such as cheese, eggs, fish, lima beans, milk, potatoes, red meat, soy products, and yeast.

As lysine is so readily available, lysine deficiency is rare but do occur. Deficiency symptoms include the following:

  1. blood-shot eyes
  2. hair loss
  3. an inability to concentrate
  4. irritability
  5. lack of energy
  6. poor appetite
  7. reproductive disorders
  8. retarded growth and weight loss.

Uses:

  • helps boost immune response
  • is needed for hormone production
  • helps with growth and maintenance of bones in both children and adults.
  • promotes the formation of both collagen and muscle protein, may help speed recovery from surgery and sports injuries.

Anti-viral applications:

used to boost the immune response against the herpes virus. Is an over-the-counter supplement taken to decrease the frequency and severity of cold sore outbreaks (caused by the herpes simplex virus-2).

Lysine helps prevent the body’s absorption of the amino acid arginine, which the herpes virus must have in order to replicate.

Studies have shown that taking supplemental L-lysine in combination with vitamin C and flavonoids can effectively fight and/or prevent herpes outbreaks.

Lysine supplements have also been used to prevent eruptions of shingles caused by the herpes varicella zoster virus.

Dosing:
  
  • Individuals with herpes outbreaks usually take 500 to 1000 milligrams each day in capsules, although those with herpes generally take as much as 6 grams each day to control their symptoms.
  • Doses of more than 10 grams each day may cause stomach cramps or diarrhea.
  • In very large doses (10 to 30 grams a day), lysine increases the toxicity of aminoglycoside antibiotics, such as gentamicin, neomycin, and streptomycin.

VitaminStuff.com. (2011). Lysine. Retrieved February 27, 2011 from http://www.vitaminstuff.com/amino-acid-lysine.html

Radiofequency ablation (RFA)

a medical procedure where part of the electrical conduction system of the heart, tumor or other dysfunctional tissue is ablated.

Zostavax Vaccine Preparation

Vaccine preparation information:

Lyzophilized strain of live attenuated varicella zoster virus initially obtained from a child with naturally occurring varicella zoster virus (VZV).

This strain was inoculated into human embryonic lung cell cultures.

The line was then adapted to and inoculated and propagated in guinea pig cell cultures. It was finally propagated in diploid human cell cultures.

Vaccine dose information:

single dose: 0.65mL

contains a minimum of 19,400 PFU (plaque-forming units) of VZV.

Each dose also contains:

  1. 31.16 mg of sucrose
  2. 15.58 mg of hydrolyzed porcine gelatin
  3. 3.99 mg of sodium chloride
  4. 0.62 mg of monosodium L-glutamate
  5. 0.57 mg of sodium phosphate dibasic
  6. 0.10 mg of potassium phosphate monobasic
  7. 0.10 mg of potassium chloride
  8. residual components of MRC-5 cells including DNA and protein
  9. trace quantities of neomycin and bovine calf serum.

The product contains no preservatives.

Injection:

Subcutaneous, preferably in upper arm.

Adverse reactions (table shown from clinical trail)

Adverse Experience
ZOSTAVAX
(N = 3345)
%
Placebo
(N = 3271)
%
Injection Site
Erythema†
33.7
6.4
Pain/tenderness†
33.4
8.3
Swelling†
24.9
4.3
Hematoma
1.4
1.4
Pruritus
6.6
1.0
Warmth
1.5
0.3
Systemic
Headache
1.4
0.8

RxList. (2006). Zostavax drug description. Retrieved February 25, 2011 from http://www.rxlist.com/zostavax-drug.htm

Zostavax – the Shingles vaccine

Vaccine developed by Merck Frosst in 2006 to treat postherpetic neuralgia. The vaccine, Zostavax has been clinically shown to reduce the incidence of shingles in individuals over 60 years of age by 51%.

Shingles is caused by subsequent symptomatic replications of the Herpes Zoster virus. The Herpes Zoster virus causes what is commonly refered to as chickenpox on its primary infection and symptomatic replicative outbreak.

Why get the vaccine?

Subsequent replications of the Herpes zoster virus manifest in painful blisters and finally crust over in lesions known as shingles.

Between symptomatic phases the herpes zoster virus remains dormant or latent in nerve roots. When the virus once again becomes active it affects the nerve causing symptoms of paresthesia, or altered nerve sensation the length of the nerve to the skin. The skin lesions, shingles are painful in themselves, however the paresthesia  may cause minor itching or may be severe, causing burning or nerve pain known as neuralgia.

The primary purpose of this vaccine is to manage the severe symptoms of nerve pain or neuralgia which may occur in some individuals with shingles. Studies have shown that Zostavax reduces the incidence of severe and long-lasting zoster-associated pain by 73 per cent in comparison to non-vaccinated individuals.

Medisys. (2011). New Shingles Vaccine – Is It Right for You? Retrieved February 24th from http://www.medisys.ca/travel-health/vaccinations/zostavax-shingles-vaccine.htm

Herpetic Whitlow

Skin lesion on the fingers or thumb caused by the herpes simplex virus, HSV-1 or -2.

Method of infection:

  • often contracted by health care workers who come in contact with the virus
  • most commonly contracted by dental workers and medical workers exposed to contaminated oral or genital secretions.
  • also often observed in thumb-sucking children with primary HSV-1 oral infection.

Symptoms:

  1. swelling
  2. reddening
  3. tenderness of the skin of infected finger.
  4. This may be accompanied by fever and swollen lymph nodes.

Small, clear vesicles initially form individually, then merge and become cloudy. 

Treatment and Management:

Lesions usually heals in two to three weeks, however, antiviral ointment may be applied topically to speed healing time.

Herpes Simplex Virus

Symptoms vary depending on whether the outbreak is initial or recurrent.

The first (primary) outbreak is usually worse than recurrent outbreaks.

Genital Herpes

Primary Genital Herpes Outbreak. For patients who do experience symptoms, the first outbreak usually occurs in or around the genital area within 1 – 2 weeks after sexual exposure to the virus. The first signs are a tingling sensation in the affected areas, (genitalia, buttocks, thighs), and groups of small red bumps that develop into blisters. Over the next 2 – 3 weeks, more blisters can appear and rupture into painful open sores. The lesions eventually dry out and develop a crust, and then heal rapidly without leaving a scar. Blisters in moist areas heal more slowly than others. The lesions may sometimes itch, but itching decreases as they heal.

About 40% of men and 70% of women develop other symptoms during initial outbreaks of genital herpes, such as flu-like discomfort, headache, muscle aches, fever, and swollen glands. (Glands can become swollen in the groin area as well as the neck.) Some patients may have difficulty urinating, and women may experience vaginal discharge.

Recurrent Genital Herpes Outbreak. In general, recurrences are much milder than the initial outbreak. The virus sheds for a much shorter period of time (about 3 days) compared to in an initial outbreak of 3 weeks. Women may have only minor itching, and the symptoms may be even milder in men.

On average, people have about four recurrences during the first year, although this varies widely. Over time, recurrences decrease in frequency. There are some differences in frequency of recurrence depending on whether HSV-2 or HSV-1 causes genital herpes. HSV-2 genital infection is more likely to cause recurrences than HSV-1.

Oral Herpes

Oral herpes (herpes labialis) is most often caused by herpes simplex virus 1 (HSV-1) but can also be caused by herpes simplex virus 2 (HSV-2). It usually affects the lips and, in some primary attacks, the mucous membranes in the mouth. A herpes infection may occur on the cheeks or in the nose, but facial herpes is very uncommon.

Primary Oral Herpes Infection. If the primary (initial) oral infection causes symptoms, they can be very painful, particularly in small children.

  • Blisters form on the lips but may also erupt on the tongue.
  • The blisters eventually rupture as painful open sores, develop a yellowish membrane before healing, and disappear within 3 – 14 days.
  • Increased salivation and foul breath may be present.
  • Rarely, the infection may be accompanied by difficulty in swallowing, chills, muscle pain, or hearing loss.

In children, the infection usually occurs in the mouth. In adolescents, the primary infection is more apt to appear in the upper part of the throat and cause soreness.

Recurrent Oral Herpes Infection. Most patients have only a couple of outbreaks a year, although a small percentage of patients experience more frequent recurrences. HSV-2 oral infections tend to recur less frequently than HSV-1. Recurrences are usually much milder than primary infections and are known commonly as cold sores or fever blisters (because they may arise during a bout of cold or flu). They usually show up on the outer edge of the lips and rarely affect the gums or throat. (Cold sores are commonly mistaken for the crater-like mouth lesions known as canker sores, which are not associated with herpes simplex virus.)

University of Maryland Medical Center. 2011.  Herpes Simplex Symptoms. Retrived February 3, 2011 from http://www.umm.edu/patiented/articles/what_symptoms_of_herpes_simplex_virus_000052_2.htm