
Gait Disorders: When the Patient Can't Walk the Walk
Gait abnormality is a general term for a pattern of walking that deviates from the normal one. (The slide shows an example of foot drop.) Locomotion is a complex coordinated process, and impairment of any of the contributing normal neural pathways can lead to an abnormal gait. Gait disorders may result from a variety of neurologic and musculoskeletal conditions, including cerebral palsy, muscular dystrophy (MD), and Charcot-Marie-Tooth (CMT) disease.[1] Most of the neurologic conditions are associated with a peculiar gait that helps lead the physician to a diagnosis.
Gait Disorders: When the Patient Can't Walk the Walk
Gait abnormalities may be divided into various general types (shown), each of which has distinct signature characteristics. These characteristics typically are readily recognizable with careful observation, thus facilitating clinical diagnosis.[1] To assess a gait disorder, one must first examine the patient's stance in primary position, then carefully observe the patient's natural walk, paying close attention to step length, arm swing, regularity, and other associated signs.
Gait Disorders: When the Patient Can't Walk the Walk
A 10-year-old boy presents with a history of eye redness, which he has had since the age of 1.5 years. The patient also has a history of gait impairment and recurrent falls. He had meningitis at the age of 3 years, and he has had recurrent chest infections since the age of 6 years. He has received symptomatic treatment for all of these recurrent infections. Examination reveals ocular telangiectasia. There is no lymphadenopathy or hepatosplenomegaly. The patient's gait is wide-based, unsteady, and irregular, with swaying of the trunk. Dysarthria and cerebellar signs are present. Serum immunoglobulin A (IgA) levels are markedly reduced. Magnetic resonance imaging (MRI) of the brain shows cerebellar atrophy.
Which of the following is the most likely diagnosis?
- Ataxia-telangiectasia (A-T)
- Multiple sclerosis (MS)
- Paraneoplastic cerebellar degeneration
- Friedreich ataxia
Gait Disorders: When the Patient Can't Walk the Walk
Answer: A. Ataxia-telangiectasia (A-T).
A-T is a multisystem disorder characterized by progressive cerebellar ataxia, oculocutaneous telangiectasia, recurrent sinopulmonary infection, and immunodeficiency.[2] The gait is a prototype of cerebellar or ataxic gait. MRI of the brain often shows nonspecific cerebellar degeneration (arrow). Cerebellar gait is typically characterized by a wide base, irregular unsteady short steps with swaying of the trunk, and a tendency to fall. In the mildest form of the disorder, the gait abnormality may be difficult to elicit. However, it can usually be demonstrated by having the patient do a "tandem walk"—that is, walk along a straight line in a heel-to-toe fashion. After a couple of steps, the patient becomes unsteady and has a tendency to fall. In addition to disorders characterized by cerebellar degeneration, cerebellar gait can be seen in MS, cerebellar stroke, and tumors involving the cerebellum (eg, medulloblastoma).
Gait Disorders: When the Patient Can't Walk the Walk
A 12-year-old boy is brought to the clinic with a 3-year history of a progressive gait disorder. He has poor eating habits. His family history is unremarkable. On examination, pallor is observed. Sensory examination shows absent vibration sense and proprioception in the lower extremities, with a positive Romberg sign (shown). Cerebellar examination reveals ataxia, present to a greater degree in the legs. Deep tendon reflexes are absent, and bilateral Babinski signs are noted.
Which of the following is the most likely diagnosis?
- CMT disease
- Friedreich ataxia
- Vitamin B12 deficiency
- Leukodystrophy
Gait Disorders: When the Patient Can't Walk the Walk
Answer: C. Vitamin B12 deficiency.
Vitamin B12 deficiency giving rise to subacute combined degeneration of the cord is one of the few disorders in which the Romberg sign and gait of sensory ataxia can be observed (the others include tabes dorsalis, Friedreich ataxia, some forms of spinocerebellar degeneration, and some sensory polyneuropathies). These disorders are characterized by loss or impairment of proprioception and vibration sense.[3] The gait has a slightly wide base, the steps are short and irregular, and the feet stamp onto the ground during movement. The Romberg sign, another characteristic feature of subacute combined degeneration of the cord resulting from vitamin B12 deficiency, is based on the principle that once visual cues are excluded, the ataxia becomes more pronounced. When the patient is instructed to stand with eyes closed and heels joined together, he or she has an exaggerated tendency to fall.
Gait Disorders: When the Patient Can't Walk the Walk
A 20-year-old man with high-arched feet (shown) complains of recent difficulty with walking and frequent falls from his toes being caught on the floor. His family medical history is significant for other members who have experienced similar difficulties. The patient is concerned about the possibility of developing "stork legs" like his brother's. On examination, he has normal stance and step length, but when he walks, overlifting and slapping of feet due to bilateral foot drop are apparent.
To which of the following conditions is the patient's foot drop most likely to be attributable?
- L5 radiculopathy
- Lumbosacral plexopathy
- Deep fibular (peroneal) neuropathy
- Chronic polyneuropathy (eg, CMT disease)
- Sciatic neuropathy
Gait Disorders: When the Patient Can't Walk the Walk
Answer: D. Chronic polyneuropathy (eg, CMT disease).
CMT disease is the most common inherited neurologic disorder and is characterized by inherited neuropathies. CMT type 1 is a demyelinating neuropathy that presents with slowly progressive distal weakness (inverted champagne-bottle appearance, shown), muscle atrophy, and sensory loss. The morbidity in CMT disease is mainly due to distal muscle weakness and foot deformities.[4,5] Pes cavus (high-arched foot) is common in this disorder.[6]
Gait Disorders: When the Patient Can't Walk the Walk
The gait in these cases is a typical steppage gait or foot drop. Stance and step length are normal. When attempting to walk, patients must overlift their feet in order to clear them off the ground, and the feet subsequently hit the ground in a slapping manner.[7] Foot drop may be either unilateral or bilateral. Unilateral foot drop is usually seen in cases of peroneal neuropathy or L5 nerve-root damage. Bilateral foot drop can be seen in severe polyneuropathies and anterior horn cell disorders (eg, spinal muscular atrophy [SMA]). In such cases, needle electromyography (EMG) reveals "neuropathic" motor units with increased duration and amplitude and reduced recruitment pattern with polyphasia (shown).
Gait Disorders: When the Patient Can't Walk the Walk
A 46-year-old man presents with complaints of having difficulty walking and having experienced several falls as a result of his right foot getting caught on the ground. He is frustrated by these complaints, explaining that walking has been a key part of his weight-loss program after recent gastric bypass surgery. On physical examination, a focal sensory deficit is noted that involves the skin of the web space between the first and second toes (green shaded area).
Which of the following is the most likely explanation for this patient's presentation?
- L5 radiculopathy
- Segmental peripheral polyneuropathy
- Deep fibular (peroneal) neuropathy
- Common fibular (peroneal) neuropathy
- Lumbosacral plexopathy
Gait Disorders: When the Patient Can't Walk the Walk
Answer: C. Deep fibular (peroneal) neuropathy.
Foot drop can result from injury to the dorsiflexors or their neural pathway (shown). Neuropathic foot drop may develop in patients who have undergone bariatric surgery, especially those who experience rapid postoperative weight loss. Deficiencies of micronutrients (eg, vitamin B12) may be a factor. Fibular (peroneal) neuropathy caused by compression at the fibular head is the most common compressive neuropathy in the lower extremity. The deep peroneal branch supplies the foot and toe dorsiflexors and has a small sensory component, which innervates only the skin of the web space between the first and second toes.[7,8]
Gait Disorders: When the Patient Can't Walk the Walk
An 8-year-old boy presents to the clinic, accompanied by his concerned parents. The patient has been having increasing difficulty with walking and with getting up off the floor. His gait is waddling. On examination, it is apparent that he also demonstrates a wide base of support with lumbar hyperlordosis and toe walking. When he gets up from the floor, he demonstrates the pattern illustrated in the slide—that is, the Gower sign.
The Gower sign results from weakness in which of the following muscle groups?
- Spinal extensors
- Knee extensor
- Hip extensors
- Plantar flexors
- Hip adductors
Gait Disorders: When the Patient Can't Walk the Walk
Answer: C. Hip extensors.
The Gower sign results from weakness in the proximal hip extensors; MD is the classic cause. Hip extensor weakness causes a forward tilt of the pelvis, which translates to hyperlordosis of the spine to maintain posture. The child then walks on tiptoe because it is easier to stay vertical with an equinovarus foot position than on a flat foot. In chronic cases, muscular contractures develop as well. To get up from a sitting or supine position to an upright one, the child must crawl up with the legs. The waddling gait is caused by proximal hip weakness and inability to support a single-leg stance, so that the weightbearing hip tends to bulge outward during walking.[9] A waddling gait may be seen in cases of chronic SMA and congenital dislocation of the hips. Needle EMG in these cases reveals "myopathic" motor units with short duration and amplitude and rapid recruitment pattern (shown).
Gait Disorders: When the Patient Can't Walk the Walk
Trendelenburg gait (shown) minimizes the force required by the hip abductors. Hip adductors normally counter gravity's pull in the swing-side pelvis by producing an abductor moment to help keep the pelvis level. Weakness may allow the pelvis to sag, and this sag may be compensated for by shifting the trunk laterally until the body vector lies over the ipsilateral hip joint.[10-12]
A 53-year-old woman presents with a complaint of progressive difficulty in walking. She states that she waddles when she walks and has been tripping more frequently. She reports low back pain with right-side radicular symptoms along her lateral thigh, anterolateral leg, and dorsal foot.
Which of the following is the most likely explanation for this patient's symptoms?
- Poliomyelitis during childhood
- Lumbar radiculopathy
- Rheumatoid arthritis
- Hip osteoarthritis
- Superior gluteal neuropathy
Gait Disorders: When the Patient Can't Walk the Walk
Answer: B. Lumbar radiculopathy.
Answers A, B, C, D, and E are all possible causes of Trendelenburg gait, but only lumbar radiculopathy accounts for the timing of onset, the presentation of pain, and the associated foot drop. Lumbosacral radiculopathy occurs in approximately 3-5% of the population. Men and women are affected equally overall, though men are most commonly affected in their 40s and women in their 50s. Between 10% and 25% of patients who have this condition develop symptoms that persist for more than 6 weeks.[9] In the slide, axial MRI shows a paracentral disc herniation adjacent to the right L5 root (arrow).
Gait Disorders: When the Patient Can't Walk the Walk
PD is a complex clinical disorder characterized by a variety of motor and nonmotor features. The cardinal findings involve the motor system.[13] The presenting feature in 70% of patients is the characteristic asymmetric distal 4- to 6-Hz resting tremor. Other features include bradykinesia or poverty of movement, lead pipe and cogwheel rigidity, postural instability and falls, motor blocks, and freezing. Patients typically exhibit a peculiar short-stepped, festinating gait with a stooped posture and poor arm swing (shown).
A 62-year-old man who has had PD for 8 years and is on levodopa therapy presents with a significant wearing-off effect and dyskinesia despite having initially responded well to medication. On examination, the patient has masklike facies and marked resting tremor in both upper extremities. There is no rigidity or cognitive impairment.
For which of the following treatments is this patient now a candidate?
- Deep brain stimulation (DBS)
- Thalamotomy
- Pallidotomy
- Stem cell transplant
Gait Disorders: When the Patient Can't Walk the Walk
Answer: A. Deep brain stimulation (DBS).
Surgical options for patients with PD include thalamotomy, pallidotomy, and DBS. DBS is a stereotactic procedure during which electrodes (inset) are placed in the subthalamic nuclei or the globus pallidus and connected to a pulse generator below the clavicles; electrostimulation is then applied to overcome the abnormal currents generated in the circuitry involved in PD. All levodopa-responsive features of PD may improve with DBS; however, this treatment is not curative and does not alter the course of the disease.[14] Patients who have had levodopa-responsive idiopathic parkinsonism for 5 years or longer and are experiencing disabling side effects are candidates for DBS. Dementia and depression must be excluded clinically. The medication dose may be reduced after surgery.
Gait Disorders: When the Patient Can't Walk the Walk
Stiff-knee gait is most commonly seen in patients with spastic hemiplegia (shown). The knee and hip maintain an extended position in swing phase rather than flexing the normal 60° at the knee and 30° at the hip. The image in the slide illustrates how the right leg is elevated off the foot plate. Even if the ankle and foot maintain an appropriate dorsiflexed position, the lack of adequate limb clearance can result in foot drag. Patients often employ compensatory mechanisms for limb clearance.[10,15]
Which of the following may be used as a potential compensatory mechanism for limb clearance by patients with stiff-knee gait due to spastic hemiparesis?
- Contralateral vaulting
- Circumduction
- Hip hiking
- Lateral trunk lean
- All of the above
Gait Disorders: When the Patient Can't Walk the Walk
Answer: E. All of the above.
The image shows a combination of lateral trunk lean and circumduction, which positions the body's center of gravity lateral to the knee joint so that there is a valgus thrust on the knee. The body's response to this thrust is a net knee adductor moment. Stiff knee, a frequent complication of stroke, is a severe hindrance during swing. Overactivity on the part of the iliopsoas, gluteus maximus, quadriceps, and hamstrings (as hip extensors) is a possible contributor to this condition. This results in a functional limb-length discrepancy. Circumduction, contralateral vaulting, hiking of the pelvis, and lateral trunk lean are all compensatory mechanisms employed for foot clearance.[7]
Gait Disorders: When the Patient Can't Walk the Walk
A 14-year-old boy presents to the clinic with deteriorated walking. Examination reveals severe knee flexion contractures due to years of knee flexor spasticity. When walking, the patient demonstrates a crouched gait, characterized by bilateral excessive knee flexion in both swing and stance phases.
For which of the following conditions is this patient's medical history most likely to be notable?
- Juvenile rheumatoid arthritis
- Legg-Calvé-Perthes disease
- Osteogenesis imperfecta
- Cerebral palsy
- Myelodysplasia
Gait Disorders: When the Patient Can't Walk the Walk
Answer: D. Cerebral palsy.
Crouched and scissoring gaits are characteristic of spastic cerebral palsy. Crouched gait is marked by hip and knee flexion due to tight hip flexors and hamstrings and weak quadriceps. Individuals may exhibit excessive ankle plantarflexion with early heel rise or excessive dorsiflexion. Patients with spastic diplegic cerebral palsy may also demonstrate a scissoring gait pattern with hips flexed and adducted, knees flexed with valgus, and ankles in equinus, resulting in toe walking. Chronic fixed-knee flexion deformities may result in avulsion injuries.[12,15,16]
Gait Disorders: When the Patient Can't Walk the Walk
An 18-year-old male patient presents with a history of manic episodes, abnormal movements, and a gait disorder. On examination, he has slightly icteric sclerae. Slit-lamp examination reveals Kaiser-Fleischer (K-F) rings in the superior margins of both corneas. He has fleeting irregular movements of facial muscles, fingers, arms, and legs. He also has brief dystonic posturing of his right arm.
Which of the following is the most likely diagnosis?
- Sydenham chorea
- Wilson disease
- Huntington disease
- Systemic lupus erythematosus
Gait Disorders: When the Patient Can't Walk the Walk
Answer: B. Wilson disease.
Wilson disease generally presents at an early age and is characterized by psychiatric, neurologic, and hepatic features, alone or in various combinations.[17] It is complicated by involuntary movements that include tremors, chorea, athetosis, and dystonia. With each step, there are different movements involving the limbs, trunk, and neck with jerking and twisting. The gait is irregular and interrupted, giving rise to a puppetlike impression.
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