From the Guidelines
Normal pressure hydrocephalus (NPH) causes a distinctive gait disturbance often described as "magnetic" or "apraxic," characterized by short, shuffling steps, a wide-based stance, and difficulty initiating movement, as noted in the context of dementia diagnosis 1. The gait pattern in NPH is unique, with patients walking with feet barely clearing the ground, and having trouble turning, which differs from Parkinson's disease.
- Key features of the gait disturbance include:
- Short, shuffling steps
- Wide-based stance
- Difficulty initiating movement
- Reduced step height
- Trouble turning
- The gait impairment in NPH results from disrupted cerebrospinal fluid dynamics affecting frontal lobe pathways that control lower limb movement, which can be assessed using MRI head without IV contrast or CT head without IV contrast as initial imaging 1. This occurs when enlarged ventricles compress neural pathways despite normal cerebrospinal fluid pressure.
- Gait disturbance is usually the first and most prominent symptom of the classic NPH triad, which also includes urinary incontinence and cognitive decline. Early recognition of this characteristic gait pattern is crucial as NPH is one of the few potentially reversible causes of dementia and gait disorders in older adults, with ventriculoperitoneal shunting being the definitive treatment 1.
From the Research
Normal Pressure Hydrocephalus Gait Disturbance
- Normal pressure hydrocephalus (NPH) is a neurological disorder characterized by a triad of symptoms: gait disturbance, dementia, and urinary incontinence 2, 3, 4.
- Gait disturbance is a key feature in the diagnosis of NPH and characterization of post-surgical outcomes 5.
- The gait disturbance in NPH is often described as a magnetic gait, with patients having difficulty initiating gait and exhibiting a slow, shuffling gait pattern 3.
- A significant positive correlation was found between age and gait disturbance in patients with iNPH, suggesting that gait disturbance may worsen with increasing age 2.
Diagnosis and Treatment
- Diagnosis of NPH is made based on suspicion of NPH symptoms, the additional finding of ventriculomegaly on imaging, and confirmatory testing with a trial of CSF drainage 3.
- Treatment of NPH involves CSF diversion, usually through implantation of a shunt from the ventricles to the peritoneal cavity 2, 3, 4.
- Gait assessment is a key feature in the diagnosis of iNPH and characterization of post-surgical outcomes, with dynamic equilibrium measurements used to assess preoperative levels of cardinal symptoms and postoperative outcomes 5.
Gait Characteristics
- Gait parameters such as self-selected walking speed and stride length have been shown to improve significantly after CSF tap test and shunt surgery in patients with iNPH 5.
- Changes in balance-related gait parameters after CSFTT and shunt surgery are still a controversial area of research, with quantitative and standardized gait analysis procedures missing 5.
- The dual-task paradigm after CSFTT could improve the clinical evaluation of higher level frontal gait disturbances in patients with suspected iNPH before shunting 5.