Classification & Assessment in Psychiatry · Paper A
Gait disorders
Gait disorders localise to specific, different levels of the nervous system, and the pattern of walking itself often reveals exactly where the problem lies before any scan is done. For example, imagine a patient whose feet seem 'glued to the floor' when starting to walk, yet who has entirely normal strength when tested lying down. In practice, that mismatch points to gait apraxia, not a muscle or nerve problem.
Parkinsonian gait, from basal gangliaA group of deep brain structures that help control movement and are affected in Parkinson's disease and by antipsychotic drugs.Read more → dopamine loss, shows shuffling, festination (an involuntary speeding up), reduced arm swing, and a stooped posture. Cerebellar ataxic gait is wide-based and irregular, with poor coordination present regardless of whether the eyes are open or closed. Sensory ataxic gait comes from loss of position sense in the legs and is high-stepping, with a positive Romberg sign, worsening markedly with the eyes closed. Gait apraxia, from frontal lobeThe front part of the brain, involved in planning, personality and impulse control.Read more → damage or normal pressure hydrocephalus, produces a magnetic, hesitant gait despite entirely normal limb power when tested lying down. Atypical parkinsonian syndromes, such as progressive supranuclear palsy, mimic Parkinson's disease but show early red flags, such as falls, and respond poorly to levodopa. Picture a patient whose gait is markedly worse with their eyes closed than open. In practice, that eyes-closed worsening points to sensory ataxiaLoss of full control of body movements, causing an unsteady, uncoordinated gait or actions.Read more →, not cerebellar ataxia.
Long before a scan is ordered, watching a patient walk across the room often localises the problem to a specific level of the nervous system. A gait disorder is any abnormal pattern of walking, and different diseases damage different parts of the motor and sensory pathways, with each damaged level producing its own recognisable pattern.
A gait disorder simply means walking looks or feels abnormal in a specific, describable way: shuffling, wide-based, high-stepping, or something else, and each specific pattern points toward a specific part of the nervous system, rather than "gait disorder" being one single diagnosis in itself.
For example, imagine a patient whose feet seem "glued to the floor" the moment they try to start walking, yet whose strength is entirely normal when tested lying down on the bed. That mismatch between a severely disturbed gait and normal supine power is itself a diagnostic clue, pointing to a problem in how movement is planned rather than a weak muscle or damaged nerve. Never assume a strange gait means weakness until you have actually tested power on the bed and found it normal or abnormal: the gap between the two findings is where the diagnosis often lives.
Think of gait as the end product of several systems working together: the (deep brain structures that smooth out and initiate movement), the cerebellum (the brain region coordinating balance and precision), the dorsal columns (spinal cord pathways carrying position sense from the legs), peripheral nerves, and the , which plan the sequence of stepping. Damage anywhere in this chain changes the walk in a characteristic way, and recognising the pattern lets a clinician localise the lesion clinically before any imaging is done.
Parkinsonian gait comes from dopamine loss. It shows shuffling, festination (an involuntary speeding up of steps as if chasing one's own centre of gravity), reduced arm swing, and a stooped posture. Cerebellar ataxic gait is wide-based and irregular, with poor coordination that stays equally bad whether the patient's eyes are open or closed, reflecting damage to the own coordination circuitry rather than a sensory input problem. Sensory ataxic gait arises from loss of position sense (proprioception) in the legs, usually from dorsal column or peripheral nerve disease; it is high-stepping and worsens markedly with the eyes closed, forming the basis of a positive Romberg sign. Spastic or scissoring gait reflects upper motor neuron damage, producing stiff, circumducted legs that cross with each step. High-stepping or foot-drop gait comes from peripheral nerve damage, such as a common peroneal nerve palsy, where the foot cannot be lifted at the ankle. Waddling gait reflects proximal myopathy (weakness of the muscles closest to the trunk), producing a side-to-side pelvic tilt rather than any problem with foot . Gait apraxia, from damage or normal pressure hydrocephalus (NPH), produces a magnetic, hesitant, shuffling gait despite entirely normal limb power and coordination on the bed. NPH classically presents with a triad of this magnetic gait, urinary incontinence, and cognitive decline, alongside ventricles that look disproportionately enlarged on imaging.
Consider a patient whose gait is markedly worse with their eyes closed than with their eyes open: that specific eyes-closed worsening points to sensory , not cerebellar ataxia, because cerebellar coordination does not depend on visual input the way compensated proprioceptive loss does. Now imagine a second patient whose parkinsonism responds poorly to levodopa, and who has early falls together with abnormal eye movements. This pattern points toward an atypical parkinsonian syndrome, such as progressive supranuclear palsy, rather than idiopathic Parkinson's disease, where levodopa response is usually good and falls tend to occur later in the illness course. These two comparisons: eyes-open-versus-closed for the ataxias, and levodopa response plus red flags for the parkinsonisms, are the pairs examiners most often use to test whether you can tell true look-alikes apart.
The first investigation is always a careful neurological examination: watching the gait itself, testing tone, power, reflexes, coordination, and sensation, and performing the Romberg test. NICE guidance on falls in older people recommends a multifactorial assessment covering gait, balance, and mobility whenever an older adult presents with a fall or a new gait problem, rather than treating the gait change in isolation. A patient with a positive Romberg sign and high-stepping gait needs investigation for peripheral neuropathy or dorsal column disease, for example checking vitamin B12 levels or nerve conduction studies, rather than a cerebellar-focused work-up. A patient with suspected NPH needs brain imaging, usually MRI, showing ventricular enlargement out of proportion to any cortical atrophy, sometimes followed by a diagnostic large-volume lumbar puncture to see if temporarily removing cerebrospinal fluid improves the gait. A patient with suspected atypical parkinsonism needs careful clinical follow-up and sometimes specialist imaging, since early scans can look similar to idiopathic Parkinson's disease.
Management follows the underlying cause rather than the gait pattern alone. Parkinsonian gait from idiopathic Parkinson's disease is managed with levodopa or other medication, alongside physiotherapy focused on stepping strategies and fall prevention. NPH, when confirmed, is managed with a ventriculoperitoneal shunt (a surgical procedure diverting excess cerebrospinal fluid), which can meaningfully improve gait and cognitive symptoms if performed early. Sensory from vitamin B12 deficiency is managed with B12 replacement, while a peroneal nerve palsy causing foot drop may need an ankle-foot orthosis (a supportive brace) alongside treating the underlying nerve injury. Waddling gait from an inflammatory myopathy may respond to immunosuppressive treatment, whereas a genetic muscular dystrophy has no cure but benefits from physiotherapy and mobility aids. Across all these causes, screening for reversible contributors: vitamin deficiencies, thyroid disease, or medication side effects, is a routine, important early step, since some gait disorders are fully treatable if caught before permanent nerve or muscle damage occurs.
If a vignette gives you normal power and coordination on the bed alongside a severely abnormal gait, think frontal/apraxic gait or NPH before you think weakness or : that bed-versus-walking mismatch is the single highest-yield clue in this whole topic.
Watch how a patient walks before you order a single scan: the pattern of shuffling, wide-based, high-stepping, waddling, or magnetic gait localises the lesion, and matching that pattern to the right cause is what makes both diagnosis and management fast and specific rather than a guess.