Gait of normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) is a form of communicating hydrocephalus that classically causes a triad of dementia, gait disturbance, and urinary incontinence. Gait difficulty is typically the initial and most prominent symptom of NPH. The primary changes are slow walking, widened base, short steps, and shuffling, all nonspecific features and natural compensations seen in patients with various gait disorders.(1-4) The gait disturbance may range from mild, with only a cautious gait or difficulty with tandem walking, to severe, when unaided gait is impossible (Video). It has been referred to as a gait apraxia.

A number of gait disorders have been ascribed to frontal lobe dysfunction. Lesions of the frontal lobe, or frontal lobe connections lead to a gait disorder characterized by short, shuffling steps, a widened base and an inability to integrate and coordinate lower-extremity movements. There is particular difficulty with starts and turns. The gait of NPH shares features with other frontal lobe gait disorders, such as include reduced velocity, stride length, and step height. NPH causes more widening of the base and outwardly rotated feet and is less responsive to external cues such as marching to a cadence or in step with the examiner. As with other disorders of frontal lobe function, patients may mimic stepping motions while supine or sitting.

Gait apraxia is the loss of the ability to use the legs properly in walking, without demonstrable sensory impairment, weakness, incoordination or other apparent explanation. The patient cannot carry out purposeful movements with the legs and feet, such as kicking an imaginary ball. Patients may have the greatest difficulty initiating walking, making small, feeble, stepping movements with minimal forward progress. Eventually the patient may be essentially unable to lift the feet from the floor, as if they were stuck or glued down; or may raise them in place without advancing them (magnetic gait, gait ignition failure, start hesitation). After a few hesitant shuffles, the stride length may increase (slipping clutch gait). When trying to turn, the patient may freeze (turn hesitation). The patient may be able to imitate normal walking movements when sitting or lying down, but eventually even this ability is often lost.

References

1. Campbell WW. DeJong's the neurologic examination, 7th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2013.

2. Campbell WW. Clinical signs in neurology: a compendium. Philadelphia: Wolters Kluwer Health, 2016.

3. Factora R, Luciano M. When to consider normal pressure hydrocephalus in the patient with gait disturbance. Geriatrics. 2008;63:32-7

4. Stolze H, Kuhtz-Buschbeck JP, Drucke H, et al. Comparative analysis of the gait disorder of normal pressure hydrocephalus and Parkinson’s disease. J Neurol Neurosurg Psychiatry 2001;70:289–297.