Overview.
Neglect disorder is a condition in which there is an apparent lack of attention or impaired perceptual response to one’s own body or to objects in the visual field, called neglect. In both cases, there is a skewed attention and orientation, and this impairment involves different types of sensory, motor, and memory modalities, giving rise to a range of clinical manifestations. Neglect disorder is caused by lesions of the right parietal lobe, and motor neglect is also seen in the medial or dorsolateral frontal lobes, as well as cortical or subcortical lesions in the temporal regions, and in the thalamus, caudate nucleus, nucleus accumbens, and internal capsule. Sensory neglect and lateralized spatial neglect are often caused by lesions in the subparietal lobule of the nondominant hemisphere or the posterior thalamus, and are also seen in the parietal lobe of the dominant hemisphere, the medial and dorsal lateral aspects of the frontal lobe, and the posterior limb of the basal nucleus and internal capsule.
Etiology
Unilateral neglect is a group of syndromes caused by injury to one side of the brain, most commonly in the parietal-occipital-temporal junction region of the right brain. It is most commonly seen in patients after cerebrovascular disease and stereotactic brain disruption surgery, but also in traumatic brain injury and brain tumors. In rehabilitation after brain injury, unilateral neglect affects the recovery of function of the affected limb and the ability to perform daily life. The presence of spatial neglect in the acute phase is associated with poor recovery of daily life function. Patients with right hemispheric injury have more motor deficits and slow functional recovery. Left hemiparesis with visuospatial deficits and physical imagery deficits is associated with poor functional recovery.
Symptoms
1. Motor neglect
The patient usually uses only one right hand to do things and make gestures, while the other left hand seems to be forgotten and left unused; the affected arm does not swing or rarely swings when walking, like patients with hemiparetic Parkinson’s disease; and remains motionless for a long time when the affected arm is in a very uncomfortable position. Neglect of the lower extremities; the affected side often bumps against obstacles when walking; when a pair of shoes is placed in front of the patient, the patient wears only the one on the healthy side and neglects the one on the affected side.
Examination of motor neglect: let the patient do bilateral repetitive movements, such as asking the patient to open and clench both fists at the same time for 20 times in a row, normal people can do bilateral repetitive movements at the same time without error, but the patient does one side continuously while the other side does not do it or obviously misses to do it; when stimulating the neglected side of the limb, whether it is a needle, pinch, pinch the skin, or forcefully flex the ring finger of the side, the patient will say that it hurts but does not retract the hand; suggesting that the patient is not to the injurious stimuli, the patient is not to the injured side of the limb; the patient is not to the affected side of the stimuli. This is a common and valuable sign in motor neglect; it suggests that the patient is not experiencing an impairment in the perception of injurious stimuli, but rather an impairment in responding to injurious stimuli.
It is rare to see pure motor neglect in clinical practice, and is often accompanied by some degree of sensory neglect, but the motor disorder is always obvious while the sensory disorder is slight.
2. Sensory Neglect
Sensory neglect, also known as lateralized inattention, is usually manifested in the form of sensory loss. It can be somatosensory, visual, or auditory, and the patient is unable to orient to, respond to, or report stimuli from the side of the lesion; the patient’s lesion has not disrupted sensory afferent pathways or damaged primary sensory cortex or thalamic sensory nuclei. The examination method of sensory extinction: when equal stimulation is given to both sides of the patient, the patient cannot feel the stimulation on one side; however, when stimulation is given to the left and right sides respectively, the patient can feel them both.
3. Lateral spatial neglect
Also known as lateralized spatial inattention or unilateral visual neglect. Partial spatial neglect is often accompanied by left-sided isotropic hemianopsia, the latter is not essential to patients with partial spatial neglect, manifested in one side of the things, often to the left side of the field of view of the things do not pay attention to. When the patient is asked to read the headline of a newspaper, he only reads the right half and ignores the left half; when the patient is asked to count the people standing in front of his bed, he only counts the ones standing on the right and in front of him and ignores the ones standing on the left and behind him.
4. Vertical Neglect
The patient could not see the lower half of the object directly in front of him, and on a vertically oriented wooden pole, using visual-tactile and visual-tactile equalization tests, the midpoint of the patient’s point was shifted upward significantly compared with normal controls. Bilateral parieto-occipital lobe damage may result in vertical polymorphic neglect.
Examination
Neurologic tests can be categorized into three types: visual-perceptual tests, visual-writing tests, and imagery tests. The first 2 types of tests examine sensory-motor neglect, and the third type examines cognitive neglect.
1. Visual Perception Test
Visual Perception Test (VPT) examines the attentional aspect of neglect and examines the active movement of the eyeballs.
2. Visual Writing Test
Optic-writing tests are more suitable for examining the intentional aspect of neglect, including the bar test, copying diagrams, drawing tests, and bisecting straight lines.
3. Spatial Imagery Test
Spatial imagination test is to check the spatial imagination of the brain. Patients often miss the left half of an object, while controls do not.
4. Assessment of daily living
The Rivermead Behavioral Neglect Test (RBIT) is a new method of assessment, the RBIT method, which involves 9 items of daily living: including simulating eating a meal, dialing a telephone, reading a menu, telling the time (including looking at digital and non-digital clocks, and pulling out wooden clocks by hand to set the timer), searching for a designated course of action on a map, and picking up a designated coin from a pile of coins.
The correlation index between the RBIT and other routinely validated tests was 0.83, especially the bar test, copying stars, crumpled daisies and blocks. the RBIT items most sensitive to test neglect were reading the time and reading menus, and the most commonly used tests for visual readaptation (bar test, finger-forward test) were less compatible with the obstacles and activities of daily living encountered. the RBIT is an easy and rapid test suitable for detecting patients’ visual impairment. The RBIT is a quick and simple test suitable for detecting impairments and functions in patients, and it is valid in comparison with other traditional tests, allowing the screening of patients, especially those with visual neglect, in order to develop rehabilitation and readaptation programs.
Diagnosis
Diagnosis can be made on the basis of etiology, clinical manifestations and laboratory tests. The phenomenon of neglect can be categorized as prosopagnosia in cognitive disorders. Neglect is very similar to self and spatial dyscognition, so the clinical diagnosis is not easy to make. It should be differentiated from anosognosia in the absence of visual, auditory, somatosensory and consciousness disorders. Neurologic examination should exclude abnormalities due to other causes.
Differential diagnosis
Some scholars believe that the phenomenon of neglect can be categorized as anosognosia in cognitive disorders. Objectively speaking, the phenomenon of neglect is very similar to auto and spatial disorientation. Therefore, the clinical diagnosis and differentiation are not easy. The key points of identification are also similar to anosognosia. The patient does not have visual, auditory, somatosensory, and consciousness disorders. A careful neurologic examination must be performed to rule out that some of the abnormalities are due to other causes.
Treatment
The main focus of this disease is on the treatment of the primary brain disease and rehabilitation.