Tetanus

Multisystem Processes & Disorders


Clinicals - History

Fact Explanation

Introduction


Tetanus is a disease that affects the nervous system. It is characterized by muscle spasms due to the tetanospasmin toxin released by Clostridium tetani. C. tetani is an anaerobic bacterium that is commonly found in the soil.

Tetanus-prone wounds


The presence of puncture type wounds, contamination with dirt or manure, sepsis, burns, high-velocity missile injuries, or frostbite increases the risk of tetanus. Also, any wound over six hours old should be considered tetanus-prone.

Trismus


Spasms involving the masseter and temporal muscles may result in trismus, also known as lockjaw, which is an inability to open the mouth. This occurs when C. tetani reaches the spinal cord and brainstem via retrograde axonal transport. Then, the release of tetanospasmin causes defects in the anterior horn inhibition of muscular contraction. The result is involuntary, sustained muscle contraction.

Muscle rigidity


Patients present with prolonged, tonic contraction of involved muscle groups. This occurs due to the inhibition of inhibitory neuromuscular signaling from the anterior horn.

Muscle spasms


Muscle "spasms" are short-lasting muscle contractions. They may be elicited from movements or sensory stimuli. These reflex spasms occur due to hyperactivity of the lower motor neurons due to denervation.

Dysphagia


The involvement of the muscles of the tongue, pharynx, and esophagus can lead to difficulty swallowing. This occurs due to the inhibition of inhibitory neuromuscular signaling from the anterior horn.

Opisthotonus


Patients with generalized tetanus may present with arching of the back due to involvement of the dorsal extensor muscles.

Apnea/upper airway obstruction


Patients may present with shortness of breath due to involvement of the respiratory and laryngeal muscles.

Pain


Pain in tetanus occurs due to severe spasms. Atypically, pain and allodynia can occur due to the involvement of sensory nerves.

Duration


The initial symptoms of tetanus usually occur around ten days after an inoculating trauma. However, the incubation period may range from three days to three weeks.

Localized tetanus


Localized tetanus is a less common form of the disease characterized by spasm of muscles directly adjacent to the wound site. This presentation may precede generalized disease.

Cephalic tetanus


Cephalic tetanus is characterized by trismus, eyelid retraction, dysphagia, deviated gaze, and risus sardonicus. This presentation is caused by involvement of the bulbar musculature.

Introduction


Tetanus is a disease that affects the nervous system. It is characterized by muscle spasms due to the tetanospasmin toxin released by Clostridium tetani. C. tetani is an anaerobic bacterium that is commonly found in the soil.

Tetanus-prone wounds


The presence of puncture type wounds, contamination with dirt or manure, sepsis, burns, high-velocity missile injuries, or frostbite increases the risk of tetanus. Also, any wound over six hours old should be considered tetanus-prone.

Trismus


Spasms involving the masseter and temporal muscles may result in trismus, also known as lockjaw, which is an inability to open the mouth. This occurs when C. tetani reaches the spinal cord and brainstem via retrograde axonal transport. Then, the release of tetanospasmin causes defects in the anterior horn inhibition of muscular contraction. The result is involuntary, sustained muscle contraction.

Muscle rigidity


Patients present with prolonged, tonic contraction of involved muscle groups. This occurs due to the inhibition of inhibitory neuromuscular signaling from the anterior horn.

Muscle spasms


Muscle "spasms" are short-lasting muscle contractions. They may be elicited from movements or sensory stimuli. These reflex spasms occur due to hyperactivity of the lower motor neurons due to denervation.

Dysphagia


The involvement of the muscles of the tongue, pharynx, and esophagus can lead to difficulty swallowing. This occurs due to the inhibition of inhibitory neuromuscular signaling from the anterior horn.

Opisthotonus


Patients with generalized tetanus may present with arching of the back due to involvement of the dorsal extensor muscles.

Apnea/upper airway obstruction


Patients may present with shortness of breath due to involvement of the respiratory and laryngeal muscles.

Pain


Pain in tetanus occurs due to severe spasms. Atypically, pain and allodynia can occur due to the involvement of sensory nerves.

Duration


The initial symptoms of tetanus usually occur around ten days after an inoculating trauma. However, the incubation period may range from three days to three weeks.

Localized tetanus


Localized tetanus is a less common form of the disease characterized by spasm of muscles directly adjacent to the wound site. This presentation may precede generalized disease.

Cephalic tetanus


Cephalic tetanus is characterized by trismus, eyelid retraction, dysphagia, deviated gaze, and risus sardonicus. This presentation is caused by involvement of the bulbar musculature.

Clinicals - Examination

Fact Explanation

Risus sardonicus


Patients may present a characteristic facies due to inability to move the facial muscles. It is described as similar to a sardonic, or cynical smile.

Neck stiffness


The involvement of the neck musculature can lead to neck stiffness with reduced range of motion (ROM).

Trismus


Patients with trismus, or lockjaw, will show an inability to open the mouth completely. Repeated attempts to open the mouth can result in more severe trismus. This is due to the involvement of the masseter and temporal muscles.

Opisthotonus


Patients may present arching of the entire back with flexion of the arms and extension of the legs, similar to patients with a decorticate posture. This more common in generalized and neonatal tetanus due to the involvement of the musculature of the back.

Cephalic tetanus


Atypical signs may be present due to less common patterns of neuronal inactivation. This may include nystagmus, vertigo, and diplopia due to the involvement of cranial nerves.

Signs of autonomic dysfunction


Patients may present with hyperpyrexia, increased sweating, hypertension, and tachycardia. Hypotension and bradycardia are also possible. Notable fluctuations of the vital signs may also be seen. This is due to the involvement of the hypothalamic nuclei, brain stem, and autonomic nerves, leading to sympathetic overdrive. Furthermore, excessive acetylcholine release leads to parasympathetic overactivity.

Respiratory distress


Patients may present signs of respiratory distress such as labored breathing, due to the involvement of respiratory and laryngeal muscles.

Risus sardonicus


Patients may present a characteristic facies due to inability to move the facial muscles. It is described as similar to a sardonic, or cynical smile.

Neck stiffness


The involvement of the neck musculature can lead to neck stiffness with reduced range of motion (ROM).

Trismus


Patients with trismus, or lockjaw, will show an inability to open the mouth completely. Repeated attempts to open the mouth can result in more severe trismus. This is due to the involvement of the masseter and temporal muscles.

Opisthotonus


Patients may present arching of the entire back with flexion of the arms and extension of the legs, similar to patients with a decorticate posture. This more common in generalized and neonatal tetanus due to the involvement of the musculature of the back.

Cephalic tetanus


Atypical signs may be present due to less common patterns of neuronal inactivation. This may include nystagmus, vertigo, and diplopia due to the involvement of cranial nerves.

Signs of autonomic dysfunction


Patients may present with hyperpyrexia, increased sweating, hypertension, and tachycardia. Hypotension and bradycardia are also possible. Notable fluctuations of the vital signs may also be seen. This is due to the involvement of the hypothalamic nuclei, brain stem, and autonomic nerves, leading to sympathetic overdrive. Furthermore, excessive acetylcholine release leads to parasympathetic overactivity.

Respiratory distress


Patients may present signs of respiratory distress such as labored breathing, due to the involvement of respiratory and laryngeal muscles.

Differential Diagnoses

Fact Explanation

Neuroleptic malignant syndrome


Neuroleptic malignant syndrome (NMS) can present with muscle rigidity and fever. However, patients classically present with altered mental status and have a history of taking one of the known causative drugs.

Dental infection


A dental infection can lead to trismus and fever. However, rigidity of the other muscle groups will be absent.

Acute dystonic reaction


Acute dystonic reactions present with involuntary muscle contractions and possibly opisthotonus. However, patients with this condition typically have a history of taking a causative drug. They may also demonstrate an oculogyric crisis or torticollis.

Meningitis


Patients with meningitis can present with neck stiffness and fever. However, trismus, risus sardonicus, and opisthotonus are not typical.

Strychnine poisoning


Strychnine poisoning can present with severe muscle contractions, opisthotonus, risus sardonicus, and fever. However, such patients also often have vomiting and convulsions.

Neuroleptic malignant syndrome


Neuroleptic malignant syndrome (NMS) can present with muscle rigidity and fever. However, patients classically present with altered mental status and have a history of taking one of the known causative drugs.

Dental infection


A dental infection can lead to trismus and fever. However, rigidity of the other muscle groups will be absent.

Acute dystonic reaction


Acute dystonic reactions present with involuntary muscle contractions and possibly opisthotonus. However, patients with this condition typically have a history of taking a causative drug. They may also demonstrate an oculogyric crisis or torticollis.

Meningitis


Patients with meningitis can present with neck stiffness and fever. However, trismus, risus sardonicus, and opisthotonus are not typical.

Strychnine poisoning


Strychnine poisoning can present with severe muscle contractions, opisthotonus, risus sardonicus, and fever. However, such patients also often have vomiting and convulsions.

Management - Supportive

Fact Explanation

Wound debridement


Wound debridement is required to physically remove toxin-producing spores and necrotic tissue and prevent further proliferation of C. tetani.

Benzodiazepines


Benzodiazepines are useful for managing tetanus because of their muscle relaxant, anxiolytic, and sedative effects.

Magnesium sulfate


Continuous infusions of magnesium sulfate may be used to control muscle spasms and autonomic instability, while preventing the need for ventilatory support.

Labetalol


Labetalol may be useful to control the hypertension and tachycardia that occurs due to sympathetic overstimulation.

Intrathecal baclofen


Unlike oral baclofen, which poorly penetrates the blood-brain barrier (BBB), intrathecal baclofen administration has been shown to be effective for controlling severe spasms and reducing the need for ventilatory support. However, this is expensive and some studies show the incomplete resolution of symptoms and a risk of bacterial infection. Therefore, this is not widely practiced.

Ventilatory support


Patients with severe cases may require ventilatory support to prevent fatal respiratory failure.

Neuromuscular blocking agents


Neuromuscular blocking agents can be used to control refractory spasms. Non-depolarizing muscle relaxants, such as vecuronium, rocuronium, and atracurium may be safer than succinylcholine, which can cause hyperkalemia.

Wound debridement


Wound debridement is required to physically remove toxin-producing spores and necrotic tissue and prevent further proliferation of C. tetani.

Benzodiazepines


Benzodiazepines are useful for managing tetanus because of their muscle relaxant, anxiolytic, and sedative effects.

Magnesium sulfate


Continuous infusions of magnesium sulfate may be used to control muscle spasms and autonomic instability, while preventing the need for ventilatory support.

Labetalol


Labetalol may be useful to control the hypertension and tachycardia that occurs due to sympathetic overstimulation.

Intrathecal baclofen


Unlike oral baclofen, which poorly penetrates the blood-brain barrier (BBB), intrathecal baclofen administration has been shown to be effective for controlling severe spasms and reducing the need for ventilatory support. However, this is expensive and some studies show the incomplete resolution of symptoms and a risk of bacterial infection. Therefore, this is not widely practiced.

Ventilatory support


Patients with severe cases may require ventilatory support to prevent fatal respiratory failure.

Neuromuscular blocking agents


Neuromuscular blocking agents can be used to control refractory spasms. Non-depolarizing muscle relaxants, such as vecuronium, rocuronium, and atracurium may be safer than succinylcholine, which can cause hyperkalemia.

Management - Specific

Fact Explanation

Botulinum toxin


The use of botulinum toxin A may be considered for the relief of localized muscle spasms.

Human antitetanus immunoglobulin


Human antitetanus immunoglobulin (HTIg) binds to circulating tetanospasmin before it infiltrates the central nervous system.

Antibiotics


Antibiotic therapy, usually consisting of penicillin G, metronidazole, or doxycycline, may prevent further proliferation of C. tetani from the wound site.

Tetanus vaccine


Any patient with proven tetanus should receive the vaccine since contracting tetanus does not provide subsequent immunity.

Botulinum toxin


The use of botulinum toxin A may be considered for the relief of localized muscle spasms.

Human antitetanus immunoglobulin


Human antitetanus immunoglobulin (HTIg) binds to circulating tetanospasmin before it infiltrates the central nervous system.

Antibiotics


Antibiotic therapy, usually consisting of penicillin G, metronidazole, or doxycycline, may prevent further proliferation of C. tetani from the wound site.

Tetanus vaccine


Any patient with proven tetanus should receive the vaccine since contracting tetanus does not provide subsequent immunity.

References

  1. MOYNAN D, O’RIORDAN R, O’CONNOR R, MERRY C. Tetanus – A Rare But Real Threat IDCases [online] 2018 Feb 21:16-17 [viewed 20 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5945900
  2. HASSEL B. Tetanus: Pathophysiology, Treatment, and the Possibility of Using Botulinum Toxin against Tetanus-Induced Rigidity and Spasms Toxins (Basel) [online] 2013 Jan 8, 5(1):73-83 [viewed 27 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3564069
  3. COLLINS S, WHITE J, RAMSAY M, AMIRTHALINGAM G. The importance of tetanus risk assessment during wound management IDCases [online] 2014 Dec 10, 2(1):3-5 [viewed 21 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4672608
  4. RODRIGO C, FERNANDO D, RAJAPAKSE S. Pharmacological management of tetanus: an evidence-based review Crit Care [online] 2014 Mar 26, 18(2):217 [viewed 21 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4057067
  5. National Center for Immunization and Respiratory Diseases. Tetanus [online]. Centers for Disease Control and Prevention, 2019 [viewed 30 September 2019]. Available from: https://www.cdc.gov/vaccines/pubs/pinkbook/tetanus.html
  6. GULAMHUSSEIN MA, LI Y, GUHA A. Localized Tetanus in an Adult Patient: Case Report J Orthop Case Rep [online] 2016 Sep-Oct, 6(4):100-102 [viewed 27 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5288609
  7. GLMarykeSpruyt,MBChB; TvandenHeever, MBChB. The treatment of autonomic dysfunction in tetanus [online]. Southern African Journal of Critical Care, 2017 [viewed 26 September 2019]. Available from: http://www.sajcc.org.za/index.php/SAJCC/article/download/274/276
  8. BERMAN BD. Neuroleptic Malignant Syndrome: A Review for Neurohospitalists Neurohospitalist [online] 2011 Jan, 1(1):41-47 [viewed 22 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3726098
  9. P.J. DHANRAJANI AND O. JONAIDE. Trismus: Aetiology, Differential Diagnosis and Treatment [online]. ORAL SURGERY, 2002 [viewed 22 September 2019]. Available from: https://pdfs.semanticscholar.org/16f5/96c3b18dd186b19eadbd04abfbd25106f797.pdf
  10. OYEWOLE A, ADELUFOSI A, ABAYOMI O. Acute Dystonic Reaction as Medical Emergency: A Report of Two Cases Ann Med Health Sci Res [online] 2013 Jul-Sep, 3(3):453-455 [viewed 22 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3793459
  11. MONIUSZKO A, ZAJKOWSKA A, TUMIEL E, RUTKOWSKI K, CZUPRYNA P, PANCEWICZ S, RUTKOWSKI R, ZDRODOWSKA A, ZAJKOWSKA J. Meningitis, clinical presentation of tetanus. Case Rep Infect Dis [online] 2015:372375 [viewed 22 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pubmed/25789186
  12. WOOD DM, WEBSTER E, MARTINEZ D, DARGAN PI, JONES AL. Case report: Survival after deliberate strychnine self-poisoning, with toxicokinetic data Crit Care [online] 2002 Jul 10, 6(5):456-459 [viewed 22 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC130147
  13. RODRIGO C, FERNANDO D, RAJAPAKSE S. Pharmacological management of tetanus: an evidence-based review. Crit Care [online] 2014 Mar 26, 18(2):217 [viewed 30 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pubmed/25029486
  14. MAHAJAN R, KUMAR A, SINGH SK. General anesthesia in tetanus patient undergoing emergency surgery: A challenge for anesthesiologist Anesth Essays Res [online] 2014 Jan-Apr, 8(1):96-98 [viewed 27 September 2019] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4173597
  15. MARDANI MASOUD. Tetanus in Area Affected by Earthquake: Risk, Prevention and Management. Arch Clin Infect Dis [online] 2018 December [viewed 22 September 2019] Available from: doi:10.5812/archcid.87049