We report a case of a 9-year-old Caucasian Italian girl, treated for growth hormone deficiency (GHD) with recombinant human growth hormone (rhGH) at a total weekly dose of 6 mg. At the diagnosis of GHD her weight was 24.6 kg, her height was 113 cm; physical examination, mental and developmental status were all normal. The diagnosis was made on laboratory criteria (two pathological GH stimulation tests) and on the MRI of the head which excluded brain tumour and anatomical abnormalities.
Three months after starting rhGH, she complained of progressive and bitemporal headaches, nausea, vomiting, diplopia and visual loss. Acute comitant esotropia was the only abnormality in the neurological examination. Ocular fundus examination revealed bilateral papilledema and a lumbar puncture showed an increased intracranial pressure (210 mm H2O) with normal cerebrospinal fluid. An MRI scan ruled out intracranial lesions (including venous sinus thrombosis), leading to a final diagnosis of idiopathic intracranial hypertension (IIH) (pseudotumor cerebri).
Since the association between IIH and rhGH treatment has already been described, we promptly discontinued rhGH and started treatment with acetazolamide at the dose of 20 mg/kg/die. Four days after starting acetazolamide, there was no clinical improvement at all, with persistence of headaches, diplopia, nausea, vomiting and weakness. After two more days, despite increasing the dose of acetazolamide up to 30 mg/kg/die, there was no recovery. Indeed, weakness worsened, arterial blood analysis showed metabolic acidosis (pH 7.29; PCO2 31.1; HCO3 15.7; BE - 7.3), likely due to acetazolamide. Therefore we stopped acetazolamide and started the treatment with intravenous dexamethasone (0.4 mg/kg/die). After only one day there was a dramatic clinical response with complete disappearance of headache, progressive improvement in the esotropia and regression of the papilloedema. We decreased intravenous steroids, switching to oral prednisone (1 mg/kg/die) after one week. Ten days after discharge, the girl no longer had headaches nor weakness, and there was no more esotropia or diplopia. Eye examination revealed further improvement of papilloedema. Therapy was tapered down in 3 weeks with no worsening. After two weeks rhGH was restarted at a dose of 1.8 mg weekly, and progressively increased up to 6 mg weekly; the treatment was well tolerated, without any side effects.