Safe return to driving following severe acquired brain injury: role of a short neuropsychological assessment.

BACKGROUND: Driving is a complex ability requiring a broad range of motor, cognitive-behavioral and visual skills that may be impaired after severe acquired brain injury (sABI). Resumption of driving is perceived as a major need by patients, being closely linked to personal autonomy, work and social activities. AIM: The objective of this study was to identify a short battery of neuropsychological tests with predictive value with regard to safe return to driving after sABI. DESIGN: Observational study. SETTING: Outpatient of a rehabilitation center for sABI. POPULATION: A continuous series of 127 patients with stable sABI, well-reintegrated at a family and social level, dismissed since at least one year from the end of their intensive rehabilitation, enrolled between 2006 and 2014. METHODS: Patients underwent an extensive battery of neuropsychological tests (pencil and paper and specific PC programs), aimed at assessing cognitive functions, in performance and verbal tasks. The results were analyzed in relation to their on-road performance during the driving test conducted by the office of the Italian Government Authority (success or failure of the test). RESULTS: No correlations were found between demographic data, etiology, driving experience, verbal competence and the decision of the competent authority. Significant correlation was found between attention, executive functions, overall visual-spatial exploration and driving performance. CONCLUSIONS: Both "pencil and paper" and computerized tests in the cognitive domains of attentive functions, and those involving performance with visual-spatial material, are significantly correlated with the driving test outcome, even if there is not enough evidence of the relative value of off-road compared to direct on-road tests. CLINICAL REHABILITATION IMPACT: We propose a small neuropsychological battery of tests with normative data for Italian population, predictive with respect to the ability to drive safely. We recommend to use it as first screening before submitting patients to more demanding and risky on-road driving tests.

The two sides of spatial representation in neglect patients: the same spatial distortion for different patterns of performance.

Patients with neglect show disorders in horizontal space perception. It has been argued that these disorders may depend on a distortion of space that takes the form of a left-right relaxation of the representational medium that becomes progressively "relaxed" toward the contralesional space and progressively "compressed" toward the ipsilesional space (the space anisometry hypothesis). In the present paper we tested this hypothesis by using the Oppel-Kundt illusion that consists of the perception of a filled space as larger than an empty space of the same size. Two experiments were carried out with 14 brain-damaged patients with neglect, 9 brain-damaged patients without neglect and 12 healthy subjects. In the first experiment participants were requested to bisect and read words with different letter spacing simulating the way space is thought to be distorted in neglect. In the second experiment we asked the participants to physically and numerically bisect numerical intervals. The results of the two experiments are in line with the predictions of the space anisometry hypothesis. Specifically, with a background resembling the space distortion proposed by the space anisometry hypothesis, neglect signs are ameliorated in reading words and in numerically bisect numerical intervals, while they are worsened in bisecting words and physically bisect numerical intervals. These results support the idea that the abnormalities observed in typical neglect tests are due to a distorted internal representation of the outside world that takes the form of a mental continuum logarithmically distorted along the horizontal dimension.

Visual and spatial modulation of tactile extinction: behavioural and electrophysiological evidence.

Crossing the hands over the midline reduces left tactile extinction to double simultaneous stimulation in right-brain-damaged patients, suggesting that spatial attentional biases toward the ipsilesional (right) side of space contribute to the patients' contralesional (left) deficit. We investigated (1) whether the position of the left hand, and its vision, affected processing speed of tactile stimuli, and (2) the electrophysiological underpinnings of the effect of hand position. (1) Four right-brain-damaged patients with spatial neglect and contralesional left tactile extinction or somatosensory deficits, and eight neurologically unimpaired participants, performed a speeded detection task on single taps delivered on their left index finger. In patients, placing the left hand in the right (heteronymous) hemi-space resulted in faster reaction times (RTs) to tactile stimuli, compared to placing that hand in the left (homonymous) hemi-space, particularly when the hand was visible. By contrast, in controls placing the left hand in the heteronymous hemi-space increased RTs. (2) Somatosensory event-related potentials (ERPs) were recorded from one patient and two controls in response to the stimulation of the left hand, placed in the two spatial positions. In the patient, the somatosensory P70, N140, and N250 components were enhanced when the left hand was placed in the heteronymous hemi-space, whereas in controls these components were not modulated by hand position. The novel findings are that in patients placing the left hand in the right, ipsilesional hemi-space yields a temporal advantage in processing tactile stimuli, and this effect may rely on a modulation of stimulus processing taking place as early as in the primary somatosensory cortex, as indexed by evoked potentials. Furthermore, vision enhances tactile processing specifically when the left hand is placed in the hemi-space toward which the patients' attentional biases are pathologically directed, namely rightwards.

Talking to the senses: modulation of tactile extinction through hypnotic suggestion.

Following brain damage, typically of the right hemisphere, patients can show reduced awareness of sensory events occurring in the space contralateral to the brain damage. The present work shows that a hypnotic suggestion can temporarily reduce tactile extinction to double bilateral stimulation, i.e., a loss of contralesional stimuli when these are presented together with ipsilesional ones. Patient EB showed an improved detection of contralesional targets after a single 20-min hypnosis session, during which specific suggestions were delivered with the aim of increasing her insight into somatosensory perception on both sides of the body. Simple overt attention orienting toward the contralesional side, or a hypnotic induction procedure not accompanied by specifically aimed suggestions, were not effective in modulating extinction. The present result is the first systematic evidence that hypnosis can temporarily improve a neuropsychological condition, namely Extinction, and may open the way for the use of this technique as a fruitful rehabilitative tool for brain-damaged patients affected by neuropsychological deficits.

Touch to see: neuropsychological evidence of a sensory mirror system for touch.

The observation of touch can be grounded in the activation of brain areas underpinning direct tactile experience, namely the somatosensory cortices. What is the behavioral impact of such a mirror sensory activity on visual perception? To address this issue, we investigated the causal interplay between observed and felt touch in right brain-damaged patients, as a function of their underlying damaged visual and/or tactile modalities. Patients and healthy controls underwent a detection task, comprising visual stimuli depicting touches or without a tactile component. Touch and No-touch stimuli were presented in egocentric or allocentric perspectives. Seeing touches, regardless of the viewing perspective, differently affects visual perception depending on which sensory modality is damaged: In patients with a selective visual deficit, but without any tactile defect, the sight of touch improves the visual impairment; this effect is associated with a lesion to the supramarginal gyrus. In patients with a tactile deficit, but intact visual perception, the sight of touch disrupts visual processing, inducing a visual extinction-like phenomenon. This disruptive effect is associated with the damage of the postcentral gyrus. Hence, a damage to the somatosensory system can lead to a dysfunctional visual processing, and an intact somatosensory processing can aid visual perception.

The Modified Five-Point Test: normative data for a sample of Italian healthy adults aged 16-60.

The Five-Point Test is one of the various measures of figural fluency functions that have been developed as nonverbal analogues to word fluency tasks, and used in neuropsychological assessment to evaluate the ability to initiate and sustain mental productivity, and to self-monitor and regulate responding in the visual-spatial domain. The aim of the current study was to collect normative data for a version of the Five-Point Test (M-FPT) administered to a sample of Italian healthy adults aged 16-60 (n = 332). Performance on the M-FPT was scored by computing the cumulative number of unique designs (UDs) performed on a 3-min administration time. Two supplemental scores were also computed: (a) the cumulative strategies (CSs) consisting with the number of UDs incorporated into enumerative or rotational strategies; (b) the error index (ErrI), consisting with the percentage between the number of perseverative or rule-breaking errors and the number of designs overall. Multiple regression analyses revealed a significant effect of age and education, but not gender, for both UDs and CSs. Equivalent scores and cut-off scores were then determined for UDs and CSs. Descriptive statistical analyses and cut-off scores were reported for ErrI. The availability of normative data for the M-FPT will be valuable in clinical settings for assessing of executive dysfunctions on the visual-spatial subdomain of subjects with brain injury. However, in order to increase the usefulness of the test, the upper limits of the age range of the normative sample should be widened. Moreover, further analyses should be required for determining the inter-rater and test-retest reliability for M-FPT performances, and providing evidence of the sensitivity of this measure to brain disturbances generally and to frontal lobe dysfunction specifically.

Rehabilitating patients with left spatial neglect by prism exposure during a visuomotor activity.

OBJECTIVE: Adaptation to prisms displacing the visual scene rightward is a therapeutic tool for left unilateral spatial neglect (USN). We aimed at comparing the effects of the classic adaptation procedure (repeated pointing toward visual targets, control treatment, C), with those of a novel adaptation method, involving ecological visuomotor activities (experimental treatment, E). METHOD: In 10 right-brain-damaged USN patients, each treatment was given for 1 week, with a crossover design, for a total of 20 sessions, twice per day. USN was assessed by cancellation, reading, and drawing tasks, and by a standardized scale. Neurological severity was assessed by the National Institutes of Health (NIH) stroke scale (Brott et al., 1989), disability by the Functional Independence Measure (FIM) scale. RESULTS: The 2-week treatments (EC, CE) were equally effective, improving both USN, confirming previous reports (Frassinetti, Angeli, Meneghello, Avanzi, & Làdavas, 2002) and, importantly, disability. The improvement was independent of baseline performance, duration of disease, and neurological severity. Recovery took place after the first week, continued in the second week, and was stable at the follow-up of 3 months. The improvement of USN, measured by cancellation performance, and, in part, that of disability, measured through the FIM scale, were mediated by the size of the leftward aftereffects, suggesting a causal relationship between prism exposure and recovery. The E protocol was better tolerated. CONCLUSIONS: Daily life visuomotor activities, associated with prism exposure, are a useful tool for rehabilitating USN patients. This new treatment may widen the compliance with prism exposure treatments and their feasibility within home-based programs.

The spatial encoding of body parts in patients with neglect and neurologically unimpaired participants.

Body parts are represented in the brain in a very specific fashion, as compared to other three-dimensional objects, with reference to their prototypic shape and multisensory coding. However, evidence is lacking about the spatial representation of body parts. To address this issue, in Experiment 1 we first compared the metric representation of body parts and of non-bodily objects in 14 right-brain-damaged patients with left unilateral spatial neglect (USN), and in 14 neurologically unimpaired control participants. Participants bisected, by manual pointing, a three-dimensional object, or their own left forearm. Patients showed the well-known ipsilesional rightward displacement of the subjective midpoint, in both forearm and solid bisection. Both USN patients and control participants were overall more accurate in the bisection of their own forearm, relative to the extracorporeal object. In four patients this advantage of the forearm was significant in a single-case analysis, while two patients showed the opposite dissociation, being more accurate with the solid object. In Experiment 2 neurologically unimpaired participants were more accurate in the bisection of a fake forearm, as well as of their own forearm, as compared to the extrapersonal object. Overall, the results indicate that the representation of the metric of the body is more reliable than that of extrapersonal objects, and also more resistant to the disruption of spatial representations brought about by USN, possibly due to the prototypical shape of body parts. Furthermore, the double dissociation found in USN patients suggests that the metrics of body parts and of extrapersonal objects are supported by independent spatial processes.

Perseveration in left spatial neglect: drawing and cancellation tasks.

Perseveration in target cancellation tasks and in drawing by copy and from memory was investigated in 21 right-brain-damaged patients, seven with no evidence of left visuo-spatial neglect, and 14 with neglect. Eight such neglect patients showed perseveration in both cancellation and drawing tasks, although no correlation was found with the severity of neglect. Patients with perseveration were not disproportionately impaired in tasks assessing executive (fluency, Stroop colour-word interference, and Weigl's sorting test), and visuo-spatial short-term memory function. In the context of a two-component hypothesis, graphic perseveration (the first component) is a specific disorder that manifests in a variety of tasks, particularly those requiring serial graphic production. Unilateral spatial neglect (the second component) may trigger and facilitate the production of perseveration errors, with a contra-ipsilateral gradient of increasing severity.

Repetita iuvant: object-centered neglect with non-verbal visual stimuli induced by repetition.

Neglect can be ego-centered or object-centered depending on the reference frames for "left" and "right", of either the body or an object. It has been suggested that object-centered neglect is not a general phenomenon but is limited to words because only they have a true canonical representation. Here, we examined whether object-centered neglect could be observed for non-verbal material by creating, after repeated exposure, a canonical representation of a nonsense figure. Fourteen neglect patients repeatedly bisected a series of asymmetrical nonsense drawings containing two different shapes at their right and left end-points (canonical trials). In the critical trials, which were the last three in the series, the position of the two shapes was mirror-reversed. Afterwards, neglect patients were asked to draw the stimulus, which provided a further measure of whether a canonical representation of the object has been built by the patients. All the patients made rightward errors with the canonical stimuli. With mirror-reversed stimuli, the bisection errors were reversed to the contralesional side in one patient, returned to zero in one patient and significantly decreased in three patients. In addition, 10 patients reliably drew the canonical stimulus at the end of the series of trials, providing an indication that they built up a canonical representation of the stimulus. The present data provide evidence that object-centered neglect is a phenomenon that is not limited to words. The nature of a stimulus, verbal or non-verbal, is not critical for observing object-centered neglect. What is critical is the way in which material is represented by the patients.

Rightward and leftward bisection biases in spatial neglect: two sides of the same coin?

Neglect patients, when asked to bisect a horizontal line, typically show large rightward errors with long lines and a decreased error with medium length lines. With very short lines the bisection bias reverses from the right to left side of the line physical centre (the so-called crossover effect). It is commonly pointed out that such a leftward bias is difficult to explain by traditional theories of neglect. Several accounts propose two distinct mechanisms, one that works for short lines and one that works for long. In the present study we demonstrated that the crossover effect can be explained by means of a unitary mechanism that derives from the space anisometry hypothesis. This hypothesis postulates that in neglect patients representational space is progressively 'relaxed' contralesionally and progressively 'compressed' ipsilesionally. In a series of five experiments, we investigated the crossover effect in 26 right-brain damaged patients: 17 with neglect without hemianopia, 4 with neglect and hemianopia and 6 without neglect or hemianopia. Patients were to bisect or extend lines of objectively and subjectively different lengths. The modulation of subjective length was created by an Oppel-Kundt illusion that is thought to resemble the distortion of representational space that occurs with neglect. All groups, except for the patients with neglect and hemianopia, were prone to the illusion. The rightward bias was reduced when the illusion induced a perceptual distortion opposite to that thought to underlie neglect. Importantly, the strength of the illusion decreased with reducing the physical line length and reversed with very short lines. These results argue for a simple and unitary explanation of the crossover effect in spatial neglect within the framework of the space anisometry hypothesis.

Rehabilitation experience in a case of Ollier's disease.

This paper describes a case of Ollier's disease, an uncommon, nonhereditary skeletal disorder affecting enchondral ossification. The patient was referred to our Rehabilitation Unit after resection of scapular chondroma. He had previously been submitted to several surgical treatments for multiple enchondromatosis. Rehabilitation goals were increasing range of motion, relieving pain and training activities of daily living (ADL). After one month treatment, the patient reported pain relief and showed good improvement of articular function and better performances on ADL. According to our experience, it seems that rehabilitation could play a complementary role as regards surgical treatment of this complex pathology.