Recurrent Dehydration in a Young Girl
| Title: | Recurrent Dehydration in a Young Girl |
|---|---|
| Authors: | Ismail, Essam AR; Nadi, Hany M; El Din, Abbas Nour; Zaki, Mohamed |
| Publisher: | Postgraduate Medical Journal |
| Date Published: | June 01, 1997 |
| Reference Number: | 180 |
This translation by the NDI Foundation is to assist the lay reader. To provide a clear, accessible interpretation of the original article, we eliminated or simplified some technical detail and complicated scientific language. We concentrated our translation on those aspects of the article dealing directly with NDI. The NDI Foundation thanks the researchers for their work toward understanding and more effectively treating this disorder.
© Copyright NDI Foundation 2007 (JC)
Zaki, et al., report on a fifty-day-old girl who was admitted to the hospital suffering from fever and vomiting. At first her case appeared quite straightforward. She had refused to eat for four days. She was born normally at full term to healthy parents who were first cousins. When admitted, she was dehydrated and weak. She was given parenteral therapy (giving drugs or other substances through a route other than the gastrointestinal tract). After a few days she improved and was discharged.
The following week, though, she was readmitted again with further complications. Her fever, lethargy, and dehydration returned, without a history of vomiting or diarrhea in the interim. Urine volume passed over a 12-hour period was 700 ml. The biochemical values and osmolality of the blood and urine did not change despite administration of intranasal DDAVP. DDAVP is a trademark name for the preparation of desmopressin acetate - a potent synthetic analogue of vasopressin used intranasally, intramuscularly, or intravenously as an antidiuretic.
A diagnosis of nephrogenic diabetes insipidus (NDI) was made based on the polyuria (excessive urination) with dilute urine, hypernatraemic (excessive sodium) dehydration, and low urinary osmolality despite administration of intranasal DDAVP.
Her psychomotor development appeared to be normal for some years, but then she seemed to lag behind in this area. At seven years of age her psychomotor development was one year behind her peers and her weight and height were below the third percentile for her age.
Subsequent CT scans revealed further problems: bilateral symmetrical calcification of the basal ganglia (a part of the brain which helps control smooth, continuous muscle movements and start and stop movements) and calcification at the junction between the white and gray matter in the parietal region.
Discussion
Why intracranial calcification occurs in patients with NDI is still unknown. There seems to be a relationship between the calcification and hypernatraemic dehydration. This type of dehydration is known to be associated with diffuse microscopic areas of intracranial hemorrhage and microthrombosis (the presence of many, tiny blood clots within uninjured blood vessels. Blood clots normally occur within injured blood vessels and are abnormal within uninjured blood vessels.) with dead tissue cells which eventually calcify.
Researchers have observed that a direct relationship has been observed between the severity of intracranial calcification and its duration prior to diagnosis and treatment (i.e., the longer the condition goes undetected the worse it gets). In our patient, calcification was mild, probably because of few dehydration attacks.
Mental retardation resulting from calcification varies from minor to severe, and the degree of psychomotor retardation increases as calcification increases.
Treatment of this condition requires liberal fluid intake--especially during fevers--and a low sodium and protein diet to decrease the osmotic load that the kidney has to excrete. The combination of thiazide diuretics and indomethacin therapy, though little understood, reduces the urine output dramatically.
Primary NDI can be complicated by intracranial calcification which, in turn, can cause psychomotor and mental retardation. This disease should be watched extremely carefully to prevent brain damage.