Hypertensive urgency in nephrogenic diabetes insipidus with concomitant Hinman syndrome

Diabetes insipidus is a syndrome characterised by the inability to conserve water or concentrate urine, leading to excessive excretion of urine. In congenital nephrogenic diabetes insipidus (CNDI), common presentations include failure to thrive, polydipsia, polyuria and dehydration. The long trajectory of the disease, coupled with psycho-behavioural changes as a child grows, can precipitate a period of non-adherence despite initial optimal control, especially in the adolescent age group. Social inconvenience of repeated voiding and nocturnal disturbances can lead to adapted urine holding behaviour, also known as non-neurogenic neurogenic bladder (Hinman syndrome). Anatomical changes in the urinary system, such as bladder trabeculation and hydroureteronephrosis, can subsequently give rise to functional renal impairment. We present a case of CNDI with concomitant Hinman syndrome, resulting in acute renal impairment and hypertensive emergency. We aim to raise awareness of the association between these two entities.

An Unusual Case of Syringohydromyelia Presenting with Neurogenic Bladder

We report the case of a 4-year-old boy who first presented with acute pyelonephritis at the age of 6 months. Diagnostic workup revealed high-grade bilateral vesicourethral reflux (VUR). At the age of 18 months, a bulking agent was used to treat bilateral VUR. Since the VUR persisted, an open bilateral Lich-Gregoir procedure was done at the age of 3 years. Immediately after surgery, he developed acute urinary retention with hydronephrosis that resolved with the placement of dwelling urinary catheter. After removal of the catheter urinary retention relapsed so placement of suprapubic urinary catheter was indicated since he did not have sensory loss. He was started with tamsulosin (α − 1-blocker) and prophylactic antibiotics. Urodynamics were performed and suggested bladder outlet obstruction. On the basis of previous urethroscopy and the absence of neurological sequelae, the differential diagnosis of Hinman syndrome was made. After removal of the suprapubic catheter, clean intermittent catheterization was started and α-blocker continued. However, magnetic resonance imaging of the brain and the spinal cord revealed syringohydromyelia extending from thoracic spine (Th5) to conus medullaris with 6 to 7 mm in diameter. Electromyoneurogram was normal. After a follow-up of 3 years, the hydronephrosis has resolved. The patient is on clean intermittent catherization and has no urinary tract infections.

De Novo Atypical Haemolytic Uremic Syndrome after Kidney Transplantation

De novo thrombotic microangiopathy (TMA) can occur after kidney transplantation. An abnormality of the alternative pathway of complement must be suspected and searched for, even in presence of a secondary cause. We report the case of a 23-year-old female patient who was transplanted with a kidney from her mother for end-stage renal disease secondary to Hinman syndrome. Early after transplantation, she presented with 2 episodes of severe pyelonephritis, associated with acute kidney dysfunction and biological and histological features of TMA. Investigations of the alternative pathway of the complement system revealed atypical haemolytic uremic syndrome secondary to complement factor I mutation, associated with mutations in CD46 and complement factor H related protein genes. Plasma exchanges followed by eculizumab injections allowed improvement of kidney function without, however, normalization of creatinine.