RESUMO
Introduction: Nodding syndrome is an unknown neurological disorder affecting children in Northern Uganda, South Sudan and Southern Tanzania. The patient in our case report is, to the best of our knowledge, the first with the syndrome that has been serially followed up for more than three months and the information obtained provides important clue to the possible risk factor to the syndrome. Case Presentation: A 13-year-old boy diagnosed in Atanga Health Centre III using World Health Organization (WHO) surveillance case definition as probable Nodding syndrome was referred to Gulu Regional Referral Hospital with pyomyositis of abdominal wall muscle and head nodding which was not responding to treatment. Serial anthropometry and laboratory investigations including, haematology, clinical chemistry, biochemistry and muscle biopsy were conducted in a period of 3 months and compared to the nodding episodes. Complete blood count showed leucocytosis with immature granulocytes and atypical lymphocytes mainly during the infective phase of the pyomyositis but returned to normal as a result of the surgical procedure, Incision, Drainage and Debridement (I, D & D) of pyomyositis of the anterior abdominal wall muscle combined with administration of antibiotics and analgesics. The liver enzymes were high throughout the period of admission in Gulu Hospital. The renal parameters and serum electrolytes were within normal ranges during the nodding free periods but it was deranged during the nodding episodes. Abdominal ultrasound scan showed a focal mass on the right internal and external oblique muscles of the abdominal wall. Histology of the muscle showed a non-specific inflammation of the abdominal muscles with mass necrosis of the muscle and thrombosed blood vessels. These findings highlight the concurrent existence of pyomyositis in a child with Nodding Syndrome but whose nodding episodes were pronounced during the periods with imbalanced electrolyte pattern and with high anion gap. In conclusion: Nodding syndrome is an unknown neurological disorder affecting children whose nodding episodes are probably related to the high Anion Gap metabolic acidosis.