Cephalic Tetanus: A Rare Form of Localized Tetanus

Tetanus is an acute toxaemic illness caused by soluble exotoxin of clostridium tetani. The localized or generalized tetanus are two major manifestation explained by the manner of transport and spread of the toxin within the central nervous system. The generalized tetanus is the most common form of the disease while the localized tetanus especially the cephalic component is extremely rare.[1,2] Here a case of Cephalic Tetanus is reported.

CASE REPORT

A 65 year old lady, whose immunization status was not known, presented with an inability to open the mouth and stiffness of the face for one day. A post traumatic wound was present over the forehead since six days. On examination her vital signs were normal. She had severe trismus and right side infranuclear facial palsy (Fig. 1). Meanwhile the patient was subjected to X-ray skull and mandible, CT and MRI of temporal bone and brain to rule out entrapment injury of right facial nerve due to trauma. However all these investigations were normal. On the 5th day her spatula test was positive and she had mild abdominal rigidity without hypertonia of the limbs. Based on the above findings the diagnosis of post traumatic cephalic tetanus entertained and patient was treated with injection penicilin, tetanus antitoxin, methocarbamil, diazepam and injection tetanus toxoid. The patient did not progress to generalized tetanus. She fully recovered and was sent home after hospitalization for one and half month.

DISCUSSION

The Cephalic Tetanus is a rare variant of local tetanus, involving 1 to 3% of total reported cases.[3] Patients without appropriate immunization may be at greater risk of contracting the disease. The CDC data suggests that most US cephalic tetanus cases follow craniofacial cutaneous injuries (laceration, puncture) or infection (acne, otitis media).[4] Cephalic tetanus origin has been associated with mouth because of gross caries, tooth extraction, root canal treatment, periodontal abscess, cheek trauma and tongue laceration.[4] Cephalic tetanus has a shorter incubation period, usually 1 to 2 days compared to other forms of tetanus (7 to 10 days).[1]

Fig 1 : Rt side Infranuclear facial palsy.

The muscles involved in cephalic tetanus are those innervated by motor nuclei of brainstem and often the cervical cord, the toxin reaching these nuclei along local i.e. regional axonal pathways.The possible pathogenesis is not only the disturbed myoneural conduction but also an axonopathy involving the nerves. Facial nerve is the most commonly involved nerve however other lower cranial nerves like 9th, 10th, 11th and 12th may also be affected.

Cephalic tetanus is characterized by facial pain, unilateral facial palsy, trismus, facial stiffness of the unparalysed half of the face, pharyngeal spasms causing dysphagia and frequent laryngeal spasms with danger of death from asphyxia. Rarely facial palsy is bilateral. Paresis of 9th and 10th nerves may follow the initial rigidity and spasms of the muscle supplied by these nerves. In some instances 7th, 8th and 9th nerves are paralysed from the very start. Even so, trismus is invariably present and leads to a correct diagnosis.[5]

Two third of Cephalic tetanus cases progress to generalized tetanus and they have bad prognosis.[6] In those who don’t progress to generalized tetanus the prognosis is good.

The differential diagnosis includes cervical pachymeningitis, subarachnoid haemorrhage, cervical tuberculous arachnoiditis and dystonic reactions. Abnormal sensorium, fever, meningeal signs, signs of raised intracranial tension point towards the diagnosis of cervical patchymeningitis or subarachnoid haemorrhage. Low grade fever, anorexia, weight loss and other constitutional symptoms favour the diagnosis of cervical tuberculous arachnoiditis. Facial and neck muscle spasms following drug ingestion (antihistaminics) point towards dystonic reaction.[1]

In our case, absence of the above features, the findings of facial wound, trismus and positive spatula test, strongly supported the diagnosis of tetanus and involvement of facial nerve clinched to the diagnosis in favour of cephalic tetanus.

REFERENCES

1.Shukla OP, Chandwani R. Cephalic tetanus case notes. JIMA 1998; 96 (8) : 254.

2. Udwadia FE. Tetanus : Oxford University press. 1994; 43.

3.Vakil B, Singhal B, Pandya S, Irani P. Cephalic tetanus. Neurology 1973; 23 (10) : 1091-6.

4.Jeffery A Burgess, George W Wambaugh, Michale J Koozarski. JADA 1992; 123 : 67-70.

5.Udwadia FE. Tetanus : Oxford University press. 1994; 73.

6.Abde VW, Dekate MP. Cephalic tetanus. JIMA 1980; 74 (6) : 111-20.