Normal Pressure Hydrocephalus
I'm currently seeing a 60 y/o gentleman with normal pressure hydrocephalus (NPH) on an outpatient basis.
He has been diagnosed for about 3 years now and was recently admitted after his shunt malfunctioned and he had a revision done. The revision helped significantly and now he's home. I've been seeing him for about a month and I'm realizing that we are plateauing. I started researching the literature for some guidelines on PT approach in this population and there is very little. Most of the articles refer to acute care management, gait characteristics of NPH vs. 
Parkinson's disease, and NPH pre/post lumbar drain testing prior to shunt placement. Nothing I can find really makes recommendations for chronic management.
As for the specifics of his case, he demos fairly common gait characteristics: small step length (festinating when fatigued) that worsens in doorways and turns and in dynamic situations. Also reduced arm swing unilaterally with ipsilateral pelvic protraction. He is easily distractible, and like many of my PD patients, cannot multitask very well. His carry over early on was good, most notably he was able to stop himself at the first sign of festination and begin his gait cycle again with focus on a good first step. This has cut down significantly his furniture walking and wall grabbing tendencies. Now, he always begins stepping well, including a fair amount of left arm swing. But soon, he is taking short steps on the left again, the trunk gets rotated anteriorly on the left, and he has to stop and start over after about 75'...and that is when walking in a straight line on level surface! Strength is near normal and tone is normal. There is mild neuropathic sensory loss in the feet due to diabetes. Endurance seems limited and has definitely been a target area. I've encouraged use of the recumbent bike at home because his fear of falling and tendency for increased instability with fatigue limit his ability to push himself with walking distance for the purpose of increasing the stamina. So my main goals are to improve his stability in a wider variety of environments, improve functional endurance, and to improve his specific ability to self-manage his home environment which is small and has lots of turns. Mostly, I've used strategies that have been successful with moderately impaired PD patients but we are hitting a wall and from what I understand from the research I have found, the two diseases appear similar, but probably impair motor planning in different ways. Therefore, some say verbal cueing doesn't work well in this group (like it does work fairly well in PD). We tried using a metronome in a couple of sessions but I'm not formally trained with it. Pretty mixed results.
So again, 2 part question: 1) What evidence based (or expert opinion based) guidelines exist for chronic management of NPH? Any articles even that address this issue? 2) What do you think about this particular patient as I've described him?
Thanks in advance for your feedback.
Jerram
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Re: Normal Pressure Hydrocephalus
Hi Jerram
Thanks for your case and your intelligent summary assessment of your patient. We had a couple of cases this year but I couldn’t find anything re: physiotherapy trials, let alone guidelines or reviews. Absolutely zilch actually!
Here are some comments:
• It sounds to me you have been treating him appropriately and rationally and I think taking a problem solving approach like you have done is the soundest way forward. Your emphasis on PD management techniques are probably the best as those are the symptoms he seems to have. Maybe has benefited from the combination of your care and neural recovery post op but is now hit a plateau – and that is just how it is.
• I couldn’t find anything on the strategy approach with normotensive hydrocephalus – could you? It seems reasonable to try it. However as you may have found with your PD patients responsiveness to strategies is variable anyway so it is more or less trial and error – if one strategy doesn’t work then try another. With the metronome was this a personal one he wears and operates himself. That is what was used in the RESCUE trial and was shown to be helpful. You can use it for both freezing and for improving step length. But it is another thing he has to operate himself. Just using an external metronome in PT sessions doesn’t seem to be much help. It is a matter of the patient having control and initiating the metronome as a strategy
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“Also reduced arm swing unilaterally with ipsilateral pelvic protraction.”
- Sounds quite asymmetrically involved. Do you find this with his step length as well?
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“and like many of my PD patients, cannot multitask very well”
– are you educating and providing strategies for reducing multitasking as much as he can? You probably are. But perhaps you could run through all the tasks he is having difficulty with and brainstorm strategies to reduce multitasking.
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“This has cut down significantly his furniture walking and wall grabbing tendencies”
- Well done!
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“he has to stop and start over after about 75'”
That sounds like typical Parkinsonian motor decay problem.
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"Endurance seems limited and has definitely been a target area”
. – Yes I agree. Given that he has diabetes, and would therefore benefit from aerobic training, poor exercise tolerance and probable motor decay this may be the best thing you could do for him. The diabetes may end up being more of a problem than the residual hydrocephalus so anything to get him more active would be good. Have you put him on a treadmill?. The external demand to step sometimes helps with the decay towards small steps and helps in setting incremental goals. Maybe a circuit program that included some upper arm ergometry, overland walking and treadmill to give him breaks and changes for his walking.
• You say he has normal strength but is that based on MMT or on something more realistic, without ceiling effects? Introducing progressive resistance training might still be worthwhile for improving balance, force generation in gait, and could be good for reducing insulin resistance. And if you included some lower intensity higher reps this may help with his endurance. Weights can be great for building up confidence and improving mood as well.
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“from what I understand from the research I have found, the two diseases appear similar, but probably impair motor planning in different ways”
– I would be interested to know what you have read. Here is one lab paper I found that I thought was interesting about Supplementary motor area improvement post surgery with normotensive hydrocephalus. It is worth reading because it may help give a perspective on your patient
Sorry not to have anything more evidentiary. I think you are right that there just isn’t anything out there. – Still maybe you might consider undertaking some research! :) It is obviously needed.
All the best with his further management
Additional Comment I forgot:
Here is that article on the SMA and normotensive hydrocephalus
Re: Normal Pressure Hydrocephalus
Thanks for your remarks GCoe.
Yes I read the Lenfeldt article. It seems that an article by Stolze in 2001 hinted at some form of Frontal Lobe dysfunction may be implicated in PD. :
"Secondly, the fact that external cues are not helpful in improving gait in normal pressure hydrocephalus raises the hypothesis that a lack of internal cues from the basal ganglia to drive the supplementary motor area and motor cortex via the ventrolateral thalamus [23] may play a minor part in the hypokinetic gait disorder in normal pressure hydrocephalus. Hypokinesia, freezing, and balance disturbance are often seen after frontal cortex lesions. Such gait disorders due to structural lesions of the frontal lobes and their connections have also been called "frontal dysequilibrium". [40] As the basal ganglia loop is projecting to the frontal cortex this may explain some of the symptomatic overlap of hypokinesia in Parkinson's disease and normal pressure hydrocephalus. Balance is not exclusively regulated at the supraspinal level. It may also be abnormal after disturbances of corticobulbar fibres and subsequent disturbance of brainstem related posture and balance systems. Thus primary frontal damage, lesion of frontocerebellar pathways, or lesioned corticocortical fibres projecting to the frontal cortex are more likely to cause the condition" - from:
Comparative analysis of the gait disorder of normal pressure hydrocephalus and Parkinson's disease. Journal of Neurology, Neurosurgery and Psychiatry March 01, 2001 | Stolze, H; Kuhtz-Buschbeck, J P; Drucke, H; Johnk, K; Illert, M; Deuschl, G
I understand this to mean that perhaps the problem is not in the BG itself (as in PD) which could influence the SMA, but rather in the SMA itself or some other area of the frontal lobe or its pathways.
Another interesting read was this article which in differentiating the gait of PD and NPH states that PD is more likely to have unilateral symptoms, (Kuba, et al. 2002) whereas with my patient clearly has more hypokinesia on his left side, especially as gait breaks down.
Also, my patient has responded somewhat to cueing that the Stolze article asserts does not work in NPH patients (in general of course). So, my patient seems to have a mix of the 2. His neurologist is convinced he has NPH and not PD b/c PD meds did not help, the shunt did, and he has the definitive mild cog and incontinence issues associated with NPH.
Thanks for your input. I will reexamine his HEP and also try a treadmill if he can get over the fear factor.
I'll try to keep you updated.
Jeremy
Re: Normal Pressure Hydrocephalus
Hi Jeremy
Thanks very much for the references. I have had a quick look at the Stolze et al 2001 article and this looks really interesting. I probably need to digest it a bit more. Could you give me the full reference for the Kuba, et al. 2002 study?
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I understand this to mean that perhaps the problem is not in the BG itself (as in PD) which could influence the SMA, but rather in the SMA itself or some other area of the frontal lobe or its pathways.
This is a very interesting idea. It is feasible isn’t it. Given the wider damage inflicted on the brain with NH than with PD it seems likely the cortex takes a direct assault – the fact that these patients often have dementia to go with it suggests a cortical involvement.
As I said I probably need to read the paper in more detail but it did get me thinking:
1. Maybe the SMA hypothesis is a bit overstated. Would it not be more likely that there is both the SMA (other cortical areas) and the Basal ganglia damage? The nature of the pathophysiology and clinical features (eg concurrent dementia) reflects this. When you look at those CTs or MRIs of NH with those grossly dilated ventricles it is hard not to see how the BG adjacent to the ventricles would not be majorly disrupted.
2. In the study the authors admitted the NH patients were more severe the NH patients were also on average 10 years older than the PD patients.The NH patients did actually increase step length but it wasn’t translated into increased velocity
3. Based on these points it could be the poorer responsiveness of the NH patients to cues could be just due to more advanced disease and age rather primarily a circuitry issue. In PD the cueing approach also only works within a “window of opportunity” and becomes less effective as the disease becomes more severe and age could also be a factor.
4. The time between doing the CSF cueing intervention was only 24 hours. This isn’t much time for the CNS to recover. Wouldn’t it be better to see the participants later down the track after tapping when there has been time for more recovery, beneficial neuroplastic changes etc. Perhaps this isn’t feasible due to the temporary nature of the procedure and in a clinical trial you would need look at patients who have undergone shunting.
I suppose until we have a some decent RCTs of gait cueing in NH we won’t really know if cueing is helpful or not. However I do agree that this casts a bit of a shadow on using cueing.
Yes do keep me posted. I do find it interesting.
Geoff
