The key difference between tetany and tetanus is that tetany is a clinical manifestation that can occur in various clinical conditions while tetanus is an infectious disease.
Although they sound similar, tetany and tetanus are not synonyms. Firstly, tetanus is an infectious disease caused by Clostridium tetani. In contrast, tetany is a clinical manifestation characterized by muscular spasms, usually with intervening periods of recovery.
CONTENT
1. Overview and Key Difference
2. What is Tetany
3. What is Tetanus
4. Relationship Between Tetany and Tetanus
5. Side by Side Comparison – Tetany vs Tetanus in Tabular Form
6. Summary
What is Tetany?
Tetany refers to muscular spasms which are usually intermittent in nature. This can occur in a myriad of clinical conditions.
Causes
- Any cause of hypocalcemia such as chronic renal failure, hypoparathyroidism
- Decreased magnesium level of the body
- Acidosis
- Toxins such as botulinum toxin, tetanospasmin
Figure 01: Trousseau’s sign seen in hypocalcemia
Tetany is actually a clinical sign and the identification of the correct etiology is necessary to treat it properly.
What is Tetanus?
Tetanus is an infectious disease affecting the central nervous system. Bacterium Clostridium tetani is the cause of this disease. This organism enters the body via breaches in the skin when the wounds are contaminated with soil containing the bacterial spores. Tetanus can occur commonly among intravenous drug abusers also due to the use of contaminated needles.
The organism itself is not invasive. It secretes a neurotoxin which is known as tetanospasmin. This toxin acts on the synapses, and results in disinhibition of the neuronal activity. At the same time, the action of the toxin gives rise to muscular spasms and neuromuscular junction blockade. These functional impairments are manifested as flexor muscle spasms. The impact of the toxin on the sympathetic nervous system causes autonomic dysfunction.
Clinical Features
The clinical features appear after an incubation period of variable duration.
- Malaise marks the onset of the disease; masseter muscle spasms causing trismus follow this.
- The facial muscle spasms cause a characteristic grinning appearance which is known as risus sardonicus.
- In severe disease, the spasms can become painful
- Spasms can occur spontaneously. In addition, the handling of the patient, light and loud noises can also trigger them.
- Dysphagia
- Dyspnea
- Tachycardia, sweating and cardiac arrhythmias
- There is a milder form of the disease (localized tetanus) where the spasms occur in the region adjacent to the wound only. The patient recovers completely.
- Cephalic tetanus is inevitably fatal and occurs when the organism enters through the middle ear.
Diagnosis
There is a clinical diagnosis and the use of investigations is minimal.
Management
In Suspected Tetanus
- 250mg of human tetanus toxoid should be given. In an already protected patient, a single booster dose is given.
Figure 02: Tetanus Vaccination
In Established Tetanus
- Supportive medical and nursing care is provided. Furthermore, nursing of the patients and looking after them in a calm, isolated and well-ventilated place is extremely effective in reducing the risk of fatal outcome.
More importantly, active immunization with boosters usually given at 10-year intervals has decreased the worldwide incidence of tetanus.
What is the Relationship Between Tetany and Tetanus?
- Tetany can occur in tetanus. In other words, tetany can manifest as a clinical sign of tetanus.
What is the Difference Between Tetany and Tetanus?
Tetany refers to muscular spasms which are usually intermittent in nature. On the other hand, Tetanus is an infectious disease affecting the central nervous system. Accordingly, tetany is a disease manifestation whereas tetanus is a disease condition that can cause tetany. Thus, this is the principal difference between tetany and tetanus.
Summary – Tetany vs Tetanus
Although these two medical terms sound similar, there is a distinct difference between tetany and tetanus. Tetany is a clinical sign or manifestation while tetanus is a disease condition. In fact, tetany can be a clinical sign of tetanus.
Reference:
1. Kumar, Parveen J., and Michael L. Clark. Kumar & Clark clinical medicine. Edinburgh: W.B. Saunders, 2009.
Image Courtesy:
1. “Troussau’s Sign of Latent Tetany” By Huckfinne – Own work (Public Domain) via Commons Wikimedia
2. “US Navy 050515-N-1485H-001 Hospitalman Mary Lewis, of Freemont, Mich., administers a tetanus shot to a child and her mother” By U.S. Navy photo by Photographer’s Mate 3rd Class Lamel J. Hinton – released by the United States Navy (Public Domain) via Commons Wikimedia