July 9, 2016
Once upon a time "arteriosclerotic (hardening of arteries) or vascular parkinsonism (VaP)" was also known as 'lower body parkinsonism.' The latter refers to a type of Parkinson's in which patients present with what is now referred to gait ignition failure. This is what President George H. W. Bush was diagnosed with a few years ago. The reason I am writing about this because more often than not this diagnosis is missed or mis- diagnosed as Parkinson's disease all too frequently which can lead to a great deal of frustration and disability.
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| President George H. W. Bush |
This is characterized by broad based slow gait, reduced stride length, start hesitation, freezing and paratonia or gegenhalten -"form of hypertonia with an involuntary variable resistance during passive movement."
Although, atherosclerotic disease CAN cause lower body PD this is by no means only etiology. This illness has no rigidity in the lower extremities. The disturbance is only evoked by gait itself. there are 3 subtypes:
- ignition (gait) apraxia (the discrepancy between the severity of gait impairment and the ability to perform other leg movements normally {e.g. cycling in the air while sitting}.
- equilibrium apraxia
- mixed gait apraxia
Although, one of the main causes of lower body PD is vascular disease such as strokes it is not the only cause. When lower body parkinsonism is caused by strokes in the frontal lobes then we can say its vascular PD (VaP). We also see abnormalities in the MRI revealing vascular disease. The Dat scan is normal for lower body PD caused by vascular causes as well as by NPH.
Another common cause is normal pressure hydrocephalus (NPH). The issue of correct classification has been complicated by the fact that patients with both vascular causes and NPH have similar amounts of freezing or start hesitation of gait. Interestingly enough although clinically we tend to distinguish them on grounds of presentation post mortem - there appears to be no difference in pathology between patients having VaP and NHP perhaps indicating similar disease. this is crucial because the treatment that works best for lower body PD caused by vascular disease is removal of spinal fluid which is the standard treatment for NPH. Vap DOES not respond to dopaminergic therapy. Although, there was a small study which suggested mild improvement with ropinorole. In my practice only treatment known to work is spinal fluid removal periodically.
NPH is a communicating hydrocephalus (fluid in brain) usually caused by trauma or infection. This causes a triad of symptoms: NL intracranial pressure (<20mmHg)
- gait apraxia (freezing),ataxia
- urinary incontinence- urgency /frequency
- dementia (cognitive decline)
Diagnosed with clinical symptoms, Lumbar puncture and a cysternogram.
Prognosis is good if diagnosed early because the longer you wait to institute shunt to remove fluid - you will not be able to reverse urinary and especially cognitive dysfunction!
Most common causes of lower-body parkinsonism.
1. Normal pressure hydrocephalus
- Idiopathic
- Secondary (meningitis, head trauma)
2. Vascular parkinsonism
- Binswanger's disease (subcortical ateriosclerotic encephalopathy)
- Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)
- Dilation of perivascular spaces (also very common in CADASIL patients)
- Multiple lacunar infarcts
3. Frontal lobe lesions
- Tumors- primary and metastatic
- Ischemia
- Demyelination- multiple sclerosis
4. Progressive supranuclear palsy- will have abnormal Dat unlike the other 3.
One key factor to remember is that proprioceptive, visual, or auditory cues are highly effective in increasing stride length and cadence in Parkinson's disease, but not so in NPH VaP which often get misdiagnosed as PD by non-experts.
NPH is a relatively rare diagnosis which is not often thought about but a cause of reversible treatable "parkinsonism." Therefore, if you or a loved one having only lower body symptoms especially if unresponsive to dopa think NPH.
Sources:
Vascular or "lower body parkinsonism": rise and fall of a diagnosis-2011 Nov30:64(11-12):385-93. PubMed
Images brain MRI of patient suspected with VaP - from nature clinical practice neurology vol4 No1
https://defeatparkinsons.com/2016/07/09/common-causes-of-lower-body-parkinsonism-by-dr-de-leon/
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