There are a couple of conditions that spring to mind as a reason for falling over while on treatment.
- Dehydration
- Unsuspected cerebral metastases
- Unsuspected spinal cord compression
- Postural hypotension due to sepsis
- resulting from chemotherapy
- resulting from UTI
The first dehydration is to be expected. The elderly can have marginal health at the best of time. A course of bladder radiotherapy can be expected to give him symptoms of cystitis - frequency, nocturia and dysuria. Haematuria at this time would be unusual if not pre-existent. This radiation cystitis by itself is of little consequence to the patient's hydration, except that the patient may learn early on that drinking fluid means more urinary activity which means more pain and difficult. This is a powerful incentive to not drink. As you will remember from your renal physiology, in chronic renal failure there is a loss of ability to concentrate urine, so while there will be a slowing of urine flow, it will not be by much and so dehydration can occur. Then we get into the cycle of postural hypotension, I rise, I fall, I can't get a drink, I rise, I fall, I get help.
Treating elderly folks is an interesting concept. They can still live a long time. They can be very sensitive to chemotherapy and surgery, in that more sed effects result. They don't have a greatly differing response to radiotherapy, except perhaps tiredness. But then I see more debilitating tiredness in the young male! And treating them can become a self-fulfilling prophecy if you don't think clearly. By this I mean that if you never treat a 80 year old properly, they will always appear to fail miserably, and so you will think they are incurable! When what you have decided is that they are untreatable! Age-ism of this sort should be confronted. Healthy 80 year olds have an average survival of at least 6-9 years, plenty long enough to achieve a 'statistical' cure, and plenty long enough to die prematurely of uncontrolled malignancy. When patients are healthy enough to take anything you throw at them, you do. But when they are older and frailer, you have to use your head.
Bladder cancers are known to go to the brain. In some ways it is easier to learn what doesn't go to the brain. Sarcomas, BCCs, prostate - these rarely go to the brain, all the others can with a varying propensity. To make falling a symptom, you would be expecting to see ataxia (cerebellum involved) or hemiplegia (cerebrum involved), may be even epilepsy being confused for a fall.
The spinal cord compression however would look very different to this. In particular you would have to ask whether there is any back pain as SpCC without pain is an uncommon occurrence. In this case the falling would be associated with leg weakness associated with a nerve root or vertebral level distribution.
Lastly, the problem could be due to sepsis following chemotherapy. As related before the elderly have more treatment-related side effects from chemotherapy. I have made it a habit to shake the patient's hand when seeing them on review. On a number of occasions I have noted that the patient is very hot to touch, and questioning has revealed that they don't feel well. That's enough of a trigger to ask for a FBC and reveal that there are no neutrophils - enough for the diagnosis of febrile neutropaenia! Of course that would presume that the patient is on chemotherapy, but then you will only know that if you ask! So that is a crucial piece of history. And even though the likelihood of chemotherapy with renal failure is remote, it is still worth the question.
So by now the tests required should be obvious. Firstly the tests required are determined by the results of the history and physical examination undertaken - as always! - structural lesions in the brain or spinal cord are best visualised by MRI, although CT scan is often a close second, but x-rays are unlikely to be very helpful. For biochemical abnormalities, urinary function tests are required, and for haematological abnormalities, full blodd count is a good place to start.
Just remember that Ockam is sometimes incorrect and the patient can have any or ALL of these causes, as well as benign conditions such as stroke.
