HISTORY, CURRENT ILLNESS AND PHYSICAL EXAMINATION

The patient is a 48-year-old male, dyslipidaemic, with non-ischaemic dilated cardiomyopathy with severe ventricular dysfunction known since 2010. Years earlier, a genetic study had been performed, with the finding of an LMNA variant of uncertain significance in a gene related to laminopathy, consistent with the patient's phenotype: non-ischaemic dilated cardiomyopathy associated with conduction disorder and ventricular arrhythmias, which had required multiple ablation procedures in the course of his disease. In addition, the patient had had a mechanical prosthesis ATS no. 25 since 2012 for a bicuspid aortic valve with severe insufficiency.
During 2016, the patient was in advanced heart failure, in NYHA functional class IV, with severe LV systolic dysfunction on echocardiography requiring repeated admissions for severe decompensation. He was therefore included on the elective list for heart transplantation (INTERMACS 4). In the following weeks he presented progressive worsening despite periodic cycles of levosimendan, with increasingly frequent decompensations due to low output and congestion, the last of which did not improve despite inotropic support (INTERMACS 2). It was decided to implant a balloon counterpulsation device and to place him on urgent cardiac transplant list 1.
Three weeks later, heart transplantation was performed by bicave technique, with good biventricular function at pump output. Immediate postoperative period without complications: little need for haemodynamic support, no rhythm disorders, extubation in the first twelve hours, no neurological deficit.
No complications from the infectious point of view, she received prophylaxis according to the centre's protocol with norfloxacin, nystatin, cotrimoxazole (recipient with negative toxoplasma and unknown donor) and valganciclovir for 15 days due to intermediate risk (positive cytomegalovirus in donor and recipient).

Immunosuppression also according to protocol, consisting of:
Two doses of basiliximab 20 mg on the first and fourth day.
Intensive corticotherapy with methylprednisolone 125 mg every 8 h on the first day, followed by prednisone 1 mg/kg/day, in a descending pattern.
Tacrolimus, starting at 0.03 mg/kg/12 h and adjusting according to levels to target between 10 and 15 ng/ml at baseline.
Mycophenolate mofetil sodium, 1,000 mg/12 h.
Without evidence of rejection in successive biopsies and with serial echocardiograms with normofunctioning graft, preserved left and right ventricular ejection fraction, without valvular heart disease or pericardial effusion.
In this context, while stable on the cardiology ward after an uncomplicated endomyocardial biopsy three hours earlier, he presented with an episode of eye twitching with sustained blinking, during which he was able to respond to commands, lasting one minute. This was followed by tonic-clonic movements of all four limbs lasting one minute.
A few minutes after cessation, during which time he remained with visual disturbances and nystagmus to the left, he presented a new episode of generalised seizure, more prolonged, which ceased with benzodiazepines (10 mg diazepam), as well as levetiracetam 1,000 mg in perfusion, both intravenous.
After resolution, the patient remained conscious, oriented and speech preserved. The threat reflex was bilaterally absent and at the time the patient reported exclusively shadow vision. Pupils were isochoric, normoreactive; leftward nystagmus maintained in primary gaze position. He was able to move all four limbs symmetrically, with the rest of the examination being unremarkable. Blood pressure was 160/90 mmHg.
Once he improved, the patient admitted having had a mild holocranial headache in the previous days.

COMPLEMENTARY TESTS
Blood tests: haemoglobin 12.1 g/dL, Ht 37%, RDW 24%, platelets 107,000/μL, the rest without alterations. Coagulation: APTT 24.7 s, the rest without alterations. Biochemistry: glycaemia 106 mg/dl, GGT 285 IU/l, protein 5.8 g/dl.
Renal function preserved (creatinine 0.88 mg/dl, GFR MDRD-4 > 60 ml/min). Ions in normal range (Na+ 138 mmol/l, K+ 4.4 mmol/l). CRP <0.1 mg/L. Venous blood gases: pH 7.21, bicarbonate 18 mg/dl, lactate 13.1 mg/dl, the rest without alterations Cranial CT scan: multiple posterior temporal and parieto-occipital hypodense lesions, as well as right frontal and in both cerebellar hemispheres, although also predominantly on the right.
Brain MRI: vasogenic oedema symmetrically affecting the subcortical white matter of almost all of both occipital lobes and occipito-parieto-temporal regions. In these areas, multiple millimetric foci of hypointensity and cortico-subcortical distribution can be seen, which are compatible with microbleeds.

EVOLUTION
The patient was immediately evaluated by Neurology, who, given the finding of seizures together with previous headache and visual disturbances in a patient being treated with tacrolimus, suspected the most likely diagnosis to be posterior reversible encephalopathy syndrome (PRES). Both CT and MRI, the latter being the technique of choice, showed images highly suggestive of this condition.
He was transferred to the intensive care unit for strict control of blood pressure and monitoring of new critical episodes. From the point of view of management, tacrolimus was withdrawn and cyclosporine was started slowly, as this was the most commonly used regimen in the literature in these cases. Mycophenolate was increased and high doses of corticotherapy were maintained until adequate therapeutic levels of calcineurin inhibitors were reached. Despite these changes, no rejection data were documented, either by ultrasound or endomyocardial biopsy. No new episodes of seizures. Progressive overall recovery, with somewhat slower recovery of visual disturbances. He was discharged 12 days after the event, neurologically asymptomatic and with control MRI, with significant improvement with respect to the previous study.

DIAGNOSIS
Reversible posterior encephalopathy syndrome (PRES) probably secondary to treatment with tacrolimus.
Generalised tonic-clonic seizures secondary to the above.
Normofunctioning orthotopic heart transplant in a patient with non-ischaemic dilated cardiomyopathy with severe left ventricular dysfunction, possible laminopathy.
