Enteric fever is a common infection of tropical countries that can have a variety of neurological complications with an incidence varying from 5% to 35%. Acute cerebellar ataxia as an isolated neurological complication of enteric fever is very rare with limited evidence.[2, 3]
A 13-year-old boy presented with high-grade intermittent fever for 5 days. He also developed progressive unsteadiness in walking and difficulty in speech since the fourth day of fever. There was no associated rash, ear pain/discharge, altered sensorium, seizures, headache, vomiting or any other significant symptoms. On examination, the child was febrile, conscious, oriented, with slurred speech and stable vital signs. Abdominal examination revealed hepatosplenomegaly (liver: 2 cm; spleen: 1 cm). Cranial nerves and sensory system were normal. There was hypotonia in all four limbs, normal power and marked ataxia. Co-ordination was affected on both sides, with presence of dysmetria, dysdiadokokinesia and impaired knee-heel test. Pendular knee jerks were elicited bilaterally. He had a wide-based gait, and tandem walking was not possible. There was no nystagmus.
Investigations revealed haemoglobin of 11 gm/dL, total leukocyte count of 2200/cu.mm. and platelet count of 70 000/cu.mm. Peripheral blood smear for malarial parasite was negative. Renal and liver function tests were normal. Magnetic resonance imaging of the head was normal. Widal test after 3 days (eighth day of illness) was positive with titres of Anti'O'1:320 and Anti'H' 1:320. Blood culture isolated Salmonella typhi, which was sensitive to ceftriaxone. The child was hence diagnosed to have enteric fever with ataxia.
Intravenous ceftriaxone was started, and the patient became afebrile after 4 days. The total leukocyte count and platelet count normalized over 7 days. Cerebellar signs improved over 2 weeks of hospital stay. Ceftriaxone was given for a period of 14 days. There was persistence of mild ataxia and incoordination at discharge, which gradually improved over next 4 weeks during follow-up.
Acute cerebellar ataxia as an isolated neurological manifestation of enteric fever is rare. Wadia et al. described 28 cases of enteric fever with cerebellar ataxia with only two of them presenting with isolated cerebellar ataxia, the rest having a combination of ataxia with pyramidal, extrapyramidal signs, deafness or protracted confusional states. Most studies show a mean time of onset of ataxia to be around 10–14 days after the onset of fever.[2, 3] Enteric fever presenting with isolated cerebellar ataxia within first few days of illness, like in our case, is uncommon with only three reported cases of early onset of cerebellar ataxia in enteric fever.
The most probable aetiopathogenesis appears to be typhoid encephalitis/cerebellitis due to predominant affliction of cerebellum with non-specific inflammatory changes like capillary thrombosis, haemorrhage, peri-vascular infiltration, demyelination, oedema and secondary neuronal changes.[4, 5]
In conclusion, acute cerebellar ataxia is an uncommon neurological complication of childhood enteric fever and can appear in the first week of illness. Being a treatable condition, enteric fever should be considered in the differential diagnosis while investigating a case of fever with cerebellar ataxia.