Bruns apraxia, or frontal ataxia, is a gait apraxia found in patients with bilateral
frontal lobe disorder
Frontal lobe disorder, also frontal lobe syndrome, is an impairment of the frontal lobe that occurs due to disease or frontal lobe injury. The frontal lobe of the brain plays a key role in executive functions such as motivation, planning, social ...
s. It is characterised by an inability to initiate the process of walking, despite the power and coordination of the legs being normal when tested in the seated or lying position. The gait is broad-based with short steps with a tendency to fall backwards. It was originally described in patients with
frontal lobe
The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a groove betwe ...
tumours
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
, but is now more commonly seen in patients with
cerebrovascular disease
Cerebrovascular disease includes a variety of medical conditions that affect the blood vessels of the brain and the cerebral circulation. Arteries supplying oxygen and nutrients to the brain are often damaged or deformed in these disorders. The ...
.
It is named after
Ludwig Bruns
Ludwig Bruns (25 June 1858 – 9 November 1916) was a German neurologist who was a native of Hanover.
He studied medicine in Göttingen (since 1878: member of Corps Hannovera Göttingen) and Munich, receiving his doctorate in 1882. Subsequently, ...
.
Symptoms and signs
Unlike ataxias of cerebellar origin, Bruns apraxia exhibits many frontal lobe ataxia characteristics, with some or all present.
* Difficulty in initiating movement
* Poor truncal mobility
* Falls due to minor balance disturbances
* Greatly hindered postural responses
* Characteristic magnetic gait, the inability to raise one's foot off of the floor.
* Wide base, poor balance control when in stance
* Short stride
* En bloc turns
Often patients with frontal lobe ataxia may experience minute cognitive changes that accompany the gait disturbances, such as frontal dementia and presentation of frontal release signs (
Plantar reflex
The plantar reflex is a reflex elicited when the sole of the foot is stimulated with a blunt instrument. The reflex can take one of two forms. In healthy adults, the plantar reflex causes a downward response of the hallux (flexion). An upward r ...
).
Urinary incontinence
Urinary incontinence (UI), also known as involuntary urination, is any uncontrolled leakage of urine. It is a common and distressing problem, which may have a large impact on quality of life. It has been identified as an important issue in geria ...
may also be present.
Bruns apraxia can be distinguished from Parkinsonian ataxia and cerebellar ataxia in a number of ways. Patients typically afflicted with Parkinsonian ataxia typically have irregular arm swing, a symptom not typically present in frontal ataxia. Walking stride in cerebellar ataxia varies dramatically, accompanied by erratic foot placement and sudden, uncontrolled lurching, not generally characteristic of Bruns apraxia.
Cause
Frontal lobe ataxia is often associated with damage to the frontopontocerebellar tract (Arnold's bundle) that connects the frontal lobe to the cerebellum. This pathway normally sends information from the cortical regions to the cerebellum, particularly information used to initiate planned movement.
Many neurologists describe frontal lobe ataxia as really an
apraxia
Apraxia is a motor disorder caused by damage to the brain (specifically the posterior parietal cortex or corpus callosum), which causes difficulty with motor planning to perform tasks or movements. The nature of the damage determines the disorder' ...
, in which voluntary control of initiating movement is greatly hindered, but normal movement is present when elicited involuntarily or reflexively. This indicates that cerebellar function is intact and that the presented symptoms of Bruns apraxia are due to damage located within frontal lobe regions and pathways leading from there to the cerebellum.George Milbry Gould; James Hendrie Lloyd. “The Philadelphia Medical Journal, Volume 6”. The Philadelphia Medical Publishing Company, 1900, page 374.
Diagnosis
Diagnosis consists of a variety of tests, including but not limited to:
* Measurement of orthostatic blood pressure
* Coordination
** rapid, alternating movements
** stroking of heel along the opposite shin from knee to ankle
** finger-to-nose testing.
* Primary sensory modalities are examined with the following methods, searching for focal sensory loss, graded distal sensory loss, or levels of decreased sensation,
hyperesthesia
Hyperesthesia is a condition that involves an abnormal increase in sensitivity to stimuli of the sense. Stimuli of the senses can include sound that one hears, foods that one tastes, textures that one feels, and so forth. Increased touch sensitivi ...
or
dysesthesia
Dysesthesia is an unpleasant, abnormal sense of touch. Its etymology comes from the Greek word "dys," meaning "bad," and "aesthesis," which means "sensation" (abnormal sensation). It often presents as painJody Corey-Bloom; Ronal B. David. “Clinical Adult Neurology”. Demos Medical Publishing, 2009, 3rd ed, page 114. .
* Focused gait examination, which examines stationary position and walking abnormalities. Walking generally exposes any faults within the complex neurological communication between systems as weight is shifted from one foot to the other.
Treatment
Treatment consists of physical rehabilitation programs designed to improve overall function, increase strength and improve balance. The ultimate goal is to increase the patient's degree of independence, thus improving the patient's quality of life. Exercise typically begins with simple movements, gradually transitioning into more complex actions. Various aspects of treatment are assessed based on the individual patient's condition, utilizing many assessment tools:
* Functional Reach Test
* External Perturbation Test – Push, Release
* External Perturbation Test – Pull
* Clinical Sensory Integration Test
* Single Leg Stance Test
* Five Times Sit to Stand TestAtaxia: Physical Therapy and Rehabilitation Applications for Ataxic Patients, 2014. http://cirrie.buffalo.edu/encyclopedia/en/article/112/#s4
Various scales are also utilized
* Brief Ataxia Rating Scale
*
Friedreich's ataxia
Friedreich's ataxia (FRDA or FA) is an autosomal-recessive genetic disease that causes difficulty walking, a loss of sensation in the arms and legs, and impaired speech that worsens over time. Symptoms generally start between 5 and 20 year ...
Impact Scale
* Scale For Assessment and Rating of Ataxia