Haemodialysis and cerebral oedema.
BACKGROUND
Haemodialysis may cause neurological symptoms ranging from inconvenient feelings of disequilibrium to life-threatening neurological complications. There are animal data to suggest cerebral swelling may accompany haemodialysis and contribute symptomatically to dialysis disequilibrium. However, MR images acquired following haemodialysis often fail to demonstrate evidence of cerebral oedema. We wished to quantify any potential cerebral volume change which is caused by haemodialysis treatment.


METHODS
Five renal patients and 5 control subjects had a two volumetric T1-weighted MRI scans on the same day. The patients were imaged immediately before and after haemodialysis. None were taking steroids. Precise positional matching (registration) was used to quantify cerebral volume change.


RESULTS
Patients had an increase in cerebral volume following dialysis which averaged 32.8 ml (SE 7.4 ml, 3% brain volume). The change in the controls was 1.4 ml (SE 0.6 ml), p < 0.001. No patient had significant neurological symptoms.


CONCLUSIONS
Cerebral oedema developed in the patients following dialysis. There is a good biological model for these observations. Modifications to dialysis may help. Common problems which increase cerebral volume, e.g. acute stroke, require careful appraisal in these patients. These observations need consideration when quantifying atrophy in dialysis patients.
Department of Clinical Neurology, St. Mary's Hospital, London, UK.
R J
RJ
Walters
N C
NC
Fox
W R
WR
Crum
D
D
Taube
D J
DJ
Thomas
D000328:Adult; D000368:Aged; D000818:Animals; D001284:Atrophy; D001834:Body Water / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology; D001929:Brain Edema / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D006435:Renal Dialysis / Q000009:adverse effects*