CLINICAL CASE OF TICK- BORNE ENCEPHALITIS COMPLICATED BY EPILEPSIA PARTIALIS CONTINUA IN ARKHANGELSK REGION

ABSTRACT

The article presents a clinical case of the tick-borne encephalitis with an alimentary transmission in a child that occurred in the Nyandomsky district of the Arkhangelsk region in 2013. Catamnestic observation of the patient was carried out from 2013 to 2020.The clinical manifestations of the disease, diagnostics and treatment methods are described. Disease led to a chronic progradient course with an outcome in epilepsia partialis continua, and caused irreversible damage to the patient's health, leading to his disability.

Keywords: tick-borne viral encephalitis, epilepsia partialis continua, diagnostics, treatment

Tick-borne encephalitis (TBE) is a viral infectious disease characterized by fever, intoxication and damage to the central nervous system. Infection in humans is transmitted through tick bites, however alimentary transmission of infection is also possible [1, 2]. Clinically, TBE usually develops in an acute cyclic form with eventual recovery, however, occasionally over time the disease might take on a chronic course. The main clinical form of the chronic course is epilepsia partialis continua (Kozhevnikov's epilepsy), characterized by a combination of local convulsive twitching of certain muscles with intermittently occurring generalized convulsive seizures [2].

The medical history of the patient was analyzed and catamnestic observation was carried out from 2013 to 2020.

Patient, 8 years and 10 months old, on the 3rd day of the disease (23.07.2013) was hospitalized in the Central regional hospital of Nyandoma with complaints of high fever (39.2°), nausea, vomiting, headaches and weakness in the muscles of the lower extremities. From epidemic anamnesis it was known that summer from June to August 2013 he spent in the countryside of Nyandoma region, where he was regularly drinking unpasteurized goat's milk. The fact of a tick bite was denied, the child was not vaccinated against tick-borne encephalitis. The study of CSF was perfomed with the following results: protein 1.067 g/l, pleocytosis 12 *106/l (lymph. 82%, neutr. 13%), antibodies to TBE IgM (11.5), IgG (12 U/l). The patient was diagnosed with the meningeal form of tick-borne encephalitis. Treatment with ribavirin, reaferon and dexamethasone was prescibed for 10 days, after which the patient was discharged from the hospital in a satisfactory condition.

On the 39th day from the onset of the disease complaints of dizziness and headaches reappeared. The results of EEG revealed pathological activity of the parietal-occipital areas with generalization to hyperventilation. The patient was taken for dispensary observation. He started studying at school, without any mental or physical restrictions. On the 53rd day from the onset of the disease, short-term muscle twitching in the right extremities began to occur up to several times a day without loss of consciousness. Due to the further deterioration of the patient's condition, it was decided to admit him back to the hospital. Neurological status: hemiparetic gait on the right, tendon reflexes from the arms and legs D > S, with clonuses, „pyramidal type“ of muscle tone on the right. Coordination tests: intention of the fingers of the right hand, myoclonia in the right hand. Antibodies to TBE (70th day) IgM(1.57), IgG (19 U/l). Based on the clinical, laboratory and instrumental data, the diagnosis was made: Tick-borne encephalitis, meningoencephalitic form, progradient course. Right-sided hemiparesis, ataxic syndrome. Kozhevnikov's epilepsy, incomplete remission. Treatment was performed (relanium and sibazone, reaferon, ribavirin, depakin-chrono 30 mg / kg / day, magnesium sulfate, glycine, magne B6), due to which the frequency and duration of myoclonia decreased, with the severity of paresis similarly decreasing. On the 70th day, he was discharged with a satisfactory condition.

On day 72, a single generalized epipleptic seizure occurred. MRI of the brain showed focal changes in the white matter of the frontal lobes, focal changes of the MR signal in the area of the bridge, arachnoid cyst of the left frontal lobe pole.

Due to a self-performed reduction of the dose of depakin-chrono (on  78th day) to 20 mg/kg / day positive symptoms of tension from the legs, tongue tremor, myoclonic head twitching appeared, myoclonia on the right with purposeful movements was increased, muscle strength in the distal extremities was decreased, hypotrophy of the right leg muscles was detected. Previous treatment did not give clinically positive dynamics, consequently a second anticonvulsant drug was prescribed (keppra 16 mg/kg/day).

In April 2014, he was examined by a neurologist. On examination: condition without positive dynamics, persistent myoclonia. He was transferred to home schooling, and put on the children's disability register.

Since May 2018, patient started to have paroxysms of numbness, movement disorders in the right extremities, tension, tremor in the right leg, more frequent during sleep and while waking up, lasting up to 15-20 minutes. The frequency of attacks went up to 2-3 times a week. The patient was getting examination and treatment in Saint –Petersburg (SPSPMU 21.10.18 - 2.11.18; PRCCID 11.03.2020 - 09.04.2020). Due to results of the examination anticonvulsant therapy was increased (keppra 1500 2 times a day (54 mg/kg), depakin 900 mg 2 times a day (32 mg/kg), it was recommended to introduce 3rd anticonvulsant drug (Zonegran 4,5mg/kg). EEG showed a positive dynamics, after which zonegran was canceled, depakin and keppra remained at the same dose.

In September 2020, another neurological examination was performed. In addition to the previous condition of the child weakness of the neck muscles, posture disorder and a misalignment of the pelvis were noted. MRI, EEG-without positive dynamics.

This clinical case is extraordinary due to the atypical transmission of infection – TBE virus entered the child's body via an alimentary way by regular consumption of  unpasteurized milk from the infected goat. Clinical and laboratory data in the beginning of disease was underestimated, short first course of antiviral therapy was carried out, which led to a chronic progradient course of the disease with an outcome in epilepsia partialis continua, and caused irreversible damage to the patient's health, leading to his disability. The appearance of severe focal forms of TBE in children in the Arkhangelsk region makes us think about the need to strengthen preventive work among the population.

References:

1. Dorko E, Hockicko J, Rimárová K, Bušová A, Popaďák P, Popaďáková J, et al. Milk outbreaks of tick-borne encephalitis in Slovakia, 2012–2016. Cent Eur J Public Health 2018; 26; pp. 47–50
2.  Infectious diseases: a national guide. 2nd ed., revised and expanded. Edited by N.D. Yushchuk, Yu.Ya. Vengerov. Moscow: GEOTAR-Media; 2018: 1104 p. (National guidelines series) (in Russian)