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BRIEF REPORT

Relation of Impairment to Everyday Competence in Visual Disorientation Syndrome: Evidence From a Single Case Study Dawn W. Langdon, PhD, Alan J. Thompson, FRCP FRCPI

ABSTRACT. Langdon DW, Thompson AJ. Relation of impairment to everyday competence in visual disorientation syndrome: evidence from a single case study. Arch Phys Med Rehabil 2000;8 1:686-9 1.

Objective: To determine the relation of neurology and neuropsychology to everyday competence.

Design: The association of these three domains was investi- gated using a single case multiple baseline design with two phases. Phase A comprised 6 weeks that coincided with an inpatient admission. Phase B comprised 3 months spent at home. A battery of visual spatial tests was completed every fortnight during the A phase and at the end of the B phase. Two new tests of relevant neurologic function with control data were developed and used weekly during the A phase and at the end of the B phase. The first test recorded the speed, accuracy, and efficiency of her walking, and the second test recorded her depth perception.

Setting: Tertiary care center. Participant: A 35year-old woman who suffered a venous

sinus thrombosis with visual disorientation syndrome. Results: During Phase A, she achieved significant functional

gains in mobility, dressing, bathing, and domestic tasks, in the context of unchanging psychometric test scores and static relevant neurologic function. During Phase B, she achieved few functional gains, despite improvements in neurologic status, demonstrated by depth perception.

Conclusions: Everyday function can progress without im- provement in neurologic and cognitive status.

Key Words: Visual disorientation; Venous sinus thrombosis; Rehabilitation.

0 2000 by the American Congress of Rehabilitation Medi- cine and the American Academy of Physical Medicine and Rehabilitation

N EUROLOGY AND neuropsychology status are primary factors in prognosis and rehabilitation, yet the mechanism

of their influence on everyday competence is unclear. There is no consensus as to which elements of a patient’s dysfunction should be the focus of neurorehabilitation. One approach is to tackle the primary cognitive impairment in the abstract, as it were, by systematic retraining.’ A second approach is to develop and encourage strategies designed to lessen the impact

From the Department of Clinical Neurology, Institute of Neurology, London, United Kingdom. This study was performed in the National Hospital for Neurology and Neurosurecrv. London. - ~.

Sobmittcd March 25, 1999. Accepted in revised form July 12. 1999. Dr. Langdon receives administrative support from the MS Society of Great Britain

and Northern Ireland. No commercial party having a direct financial interest in the results of the research

supporting this article has or will confer a benefit upon the authors or upon any organization with which the authors are associated.

Reprint requests to Dr. D.W. Langdon. Department of Clinical Neurology. Institute of Neurology. Queen Square. London WCIN 3BG UK.

0 2000 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

ooO3-9993/00/8105-5535$3.00/O doi: 10.1053/mr.2000.3803

of the primary cognitive impairment on the patient’s everyday life.?

The separate delineation of patients’ gains in independent function from their individual neurologic and neuropsychologic context is a complex task. Some investigators have tended to concentrate on their patients’ performance on retraining tasks as an outcome measure and not included measures of independent everyday function.’ Other investigators have used patients’ psychometric test scores. in comparison with those of a control group, to demonstrate the beneficial effects of a retraining program.” In addition, although the clear methodologic advan- tages of group studies make them the preferred option for investigating common conditions, there are problems of match- ing and monitoring levels of neurologic impairment. It is unclear how improvements in daily function occur indepen- dently of neuropsychologic and neurologic change.

Single-case methodology, which is necessarily accepted as a legitimate approach to the study of rarer syndromes, allows the start point, progress, and outcome of a patient to be charted with some precision across several domains.4 It thus affords the opportunity to determine the interrelation of independent everyday function, neuropsychology, and neurology. This is especially true of a focal cognitive deficit which severely disrupts daily life, where both neuropsychology and neurology can be assessed with relatively few confounding effects from other deficits. Visual disorientation syndrome is a severely disabling deficit. The syndrome arises from an impairment in the ability to localize objects in space by sight. Clinical experience of this syndrome would suggest that the disordered visual input that these patients experience can be more dis- abling than conventional blindness and their prognosis for independent function can be poor.

The syndrome results in many apparently paradoxical disas- sociations of visual capabilities. For example, patients may be able to read small print or recognize faces when the appropriate stimuli are caught in their gaze, but will not be able to walk across a room if it is normally furnished. They may be able to point efficiently on request to any part of their body, but will flail and fumble when asked to touch a pencil held a few inches in front of them. HolmesS was the first to describe in detail patients who were unable to localize the position of objects in space from visual input. The most striking feature of these cases was that they could not easily take hold of objects presented to them, or even extend their hands in the object’s direction, yet had no primary problems in perceiving or recognizing the object. Some had normal acuity, could recognize letters, and read (Holmes and Horrax6 describe a typical case). One patient reported by Holmes5 was extremely slow and awkward in taking food with a spoon, but he always brought the spoon quickly and correctly to his mouth. This illustrates that there is not a purely motor component to this syndrome, but that the primary impairment is one of localization in extrapersonal space. Furthermore, a purely visual task, judging the relative positions of two objects in space has been reported to be consistently difficult for these patients. Another patient of Holmes5 made errors when asked to say which of two objects separated by 15cm, placed half a meter from his eyes, was

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nearer to him. One of the most serious and striking disabilities that these patients experience is being unable to negotiate the topography of their home environment; this patient of Holmes,s when asked to walk between two beds, frequently turned to the right or left and stumbled against one.

Since these early case reports, a more rigorous and systemic evaluation of the syndrome has been described.’ Visual localiza- tion is now one of the recognized components of early visual processing. Other components that have been identified include color perception, tested by the distinguishing and ordering of different hues; acuity, tested by the discernment and identifica- tion of small or fine stimuli; and form perception, the distinguish- ing and identification of various and similar shapes. All of the four modalities mentioned have been demonstrated to be mutually disassociable.’ In visual disorientation syndrome, localization is severely impaired while perception of color, acuity, and form can be relatively spared.

This formal psychometric documentation of the syndrome’ explains the striking discrepancies recorded in the clinical case studies.5.6 Intact acuity and form perception allows these patients to recognize faces and even read small print accurately, once they have fixated on the targets. However, their visual disorientation renders them very inefficient at negotiating their home environment, because the position of furniture cannot be determined with any certainty or confidence. Even routes around the home traversed several times a day can never become routine, because the relative positions of furniture and doorways both to each other and to the patient’s position at any given time are not clear, and thus a source of confusion and distress. These apparent incongruities in visual function are perplexing for both patients and their families and the explana- tion of fractionation of visual processing often does little to dispel the mystery.

The aim of this study was to measure neurologic disability, neuropsychologic skills, and everyday functional competence in a patient who was visually disorientated and to investigate the interrelations among these three domains.

CASE REPORT In December 1992, a 35year-old woman, who had been born

in the Indian subcontinent and had lived in London for 10 years, gave birth to her fourth child following a full-term normal delivery. Nine days postpartum she was admitted to a general hospital with frontal headache, hypertension, and ankle edema. She developed a deterioration in her level of consciousness, weakness of the left leg, and right hemiparesis over the next 10 days, and was transferred to the National Hospital for Neurol- ogy and Neurosurgery, Queen Square, London.

On admission she was drowsy and disorientated, and al- though cooperative, her consciousness was severely compro- mised. She appeared to be blind and did not respond to menace. Her fundi were normal, with no papilloedema; her pupils were dilated, but responded to light. Her eyes were deviated to the left at rest. but a full range of ocular movements was obtained on doll’s eye maneuvers. There was no nystagmus. The remainder of the cranial nerves were intact. In the upper limbs, there was bilateral hypotonia with severe weakness of the right arm and normal power in the left arm. In the lower limbs there was an increase in tone, more marked on the right than the left. Power was severely reduced in both lower limbs with some sparing proximally on the right. Reflexes were brisk through- out, and both plantar responses were extensor. Formal assess- ment of sensation was not possible.

Computed tomography of the head showed bilateral cerebral edema extending to the periphery of each hemisphere. Subse- quent magnetic resonance imaging (MRI) of the head with MR

angiogram showed areas of high signal lying within cerebral substance involving predominantly the grey matter and subcor- tical white matter (at the grey/white matter junction [fig l]), bilateral in the parieto-occipital regions, and including the posterior frontal regions on the left. The MR angiogram showed that the superior sagittal sinus was patent posteriorly, but anteriorly it was not easily identified. The cortical veins could not be identified. The clinical findings and imaging were thought to be consistent with a diagnosis of cerebral venous sinus thrombosis. Over the subsequent 2 weeks there was a slow improvement in the patient’s neurologic condition, allow- ing a more detailed examination.

At the time, her deficits and her distress were so great that formal evaluation of the cognitive function was problematic. Because English was not her first language, her scores on the four verbal subtests of the Wechsler Adult Intelligence Scale- Revised (WAIS-R)* that she attempted could not be taken as an indication of her general intellectual function at this time, but served as a baseline for future evaluation. She achieved age-scaled scores of 4 on Digit Span, Vocabulary, and Arith- metic, and a score of 3 on Similarities. Visual field testing demonstrated bilateral inferior quadrantanopias. Bedside test- ing and observation suggested that she had suffered a severe disruption of spatial localization. For example, she was unable to replace a cup in its saucer and generally unable to locate objects by sight alone. She was, however, able to read N8 text, identify colors and faces, and discern the direction and motion of objects. This pattern of deficits would be consistent with visual disorientation syndrome.

As she began to recover from her acute neurologic condition, her need for rehabilitation became paramount and she was transferred to the Neurorehabilitation Unit (NRU) of the National Hospital 2 months after the acute onset of her condition.

Initial Intensive Rehabilitation On admission to the NRU, she was almost completely

dependent in grooming, feeding, dressing, bathing, and all aspects of mobility. This was reflected in her Barthe19 score of 5 (normal = 20) and her Functional Independence Measure (FIlMlO) motor score of 32 (normal = 9 1). She repeated the four verbal subtests of the WAIS-R and scored 4 for digit span and vocabulary, 3 for arithmetic, and 2 for similarities, at a similar level to those recorded in the case report. Although her severe visual disorientation continued to make a formal assessment of her color vision problematic, she was able to name primary colors and no problems with color were observed or reported by herself or her family. Her visual acuity was 6/12. Her form perception, assessed using an adaptation of the Efron Squares, which required her to discriminate between a square and an oblong, matched for total flux. On a relatively easy shape discrimination task she was at ceiling and on a difficult discrimination, at the limits of a healthy individual’s ability, she was just outside normal limits. In marked contrast, her scores on tests of spatial processing were very impaired and fell far below the cut-offs that defined the normal range of function- ing.” These results again support a diagnosis of visual disorien- tation syndrome.

Before the observational phases, initial physiotherapy was aimed at the facilitation of selective movements of all four limbs. She learned to be aware of the relative positions of body parts in static positions, for example, sitting and standing. Once this was achieved, she practiced moving from one position to another, for example, rolling, and sitting to standing. When she was stable in standing, gait re-education was commenced. Her initial occupational therapy was designed to help with identify-

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Fig 1. Computed tomography showing the patient’s bi-occipital lesions.

ing and locating her own body parts in relation to managing self-care tasks. Six weeks after admission to the NRU. she began walking short distances under supervision.

She continued to follow an individual goal-orientated pro- gram, which was derived from the problem list constructed on her arrival and was geared toward her achieving her long-term goal of a degree of independent domestic function. The goal-orientated approach of the NRU constituted an informal multiple baseline design. Every 2 weeks. concrete and specifc behavioral goals would be set, to address certain tasks of personal and home activity. Therapy would be directed toward these goals, which were usually achieved by the predicted date.

The rehabilitation program consisted of taught strategies in structured therapy session and reinforcement and practice around the NRU. She had to learn to move in relation to an environment from which she had received no reliable visual input. The taught strategies were designed, first, to utilize her knowledge of her own position in space in assisting her to negotiate and use objects, and second, to increase her physical confidence. Treatment strategies designed to encourage her to locate items by touch included reaching for and locating bench items from sitting, and standing, and reaching for and locating floor items from sitting. Treatment strategies designed to increase her physical confidence included floor work, to encourage stretching and reaching movements without fear of falling; supervised walking, to reduce hitting walls and door frames; and stair exercises, to reduce fear and encourage utilization of kinesthetic feedback.

The relation of neuropsychologic skills to neurologic func- tion and everyday competence were identified as being of potential clinical interest. If the trends within the areas mea-

Arch Phys Med Rehabil Vol 81, May 2000

sured were shown to differ across the two periods. some indications of how recovery of everyday competence can relate to underlying neuropsychology and neurology might be de- rived.

METHODS AND RESULTS Serial measurements were undertaken during the last 6 weeks

of an inpatient rehabilitation period (Phase A) and at 3 months after discharge home she was reassessed (Phase B). The measurements were in line with the recommendations of the institution’s ethics committee. The following measures were used.

Calibration Tasks of Neurologic Function This area was of interest for several reasons. First. the

patient’s scores on conventional tests of spatial processing were so poor that it was likely that she had “floored” on these tasks. which meant that the possibility could not be ruled out that an improvement in neurologic impairment might underpin progress in everyday competence, but might not improve her focal cognitive deficits sufftciently to enable her to score within the normal range on formal psychometric tests of spatial process- ing. Thus it was theoretically possible for some improvement to occur in her very severe neuropsychologic deficits. which was not sufftcient to increase her performance to a level that would start to register on the stringent psychometric tests. Another reason for attempting to monitor relevant neurologic function was that some general recovery in mobility. or in motor and sensory functions, might mediate gains in independent daily function. Two tasks were devised that attempted to monitor her

REHABILITATION OF VISUAL DISORIEFPTATION SYNDROME, Langdon 699

relevant neurologic impairment in visual processing and mobil- ity. The two tests were repeated weekly during Phase A, and then again at the end of Phase B.

Depth perception. Baseline. One of the bedside tests of visual disorientation. in widespread clinical use, requires that patients say which of two pencils being held at different distances before them is closest to them. In an attempt to provide a systematic and replicable version, two rows of holes, each l-inch horizontally from its partner, were drilled at equal distance from the midline of a box. The targets were two long white canes. one with the addition of a bright blue paper flag, positioned at the patient’s seated eye level to enable her to distinguish between the two canes. The two canes were placed randomly. either both in the left or both in the right rows of holes, the depths between the canes varying from I to 8 inches. She was requested to shut her eyes, while the tester positioned the canes. The tester then said “open.” She opened her eyes and, depending on which cane she thought was closest to her, said “blue” to indicate the cane with the paper flag or “white” to indicate the cane without the flag. She achieved an accuracy of over 90%. Nevertheless, her errors were erratic and she continued to make errors at each assessment up to the time of her discharge (table 1). Controls were consistently 100% accurate on this task.

Phase A. Her accuracy in judging distances was very variable across the treatment phase (table 1). A Sign Test comparing her performance at baseline and the end of Phase A was not significant (p = .7744).

Phase B. Interestingly, her scores on distance judgments improved during the second period (table I). This was con- firmed by a Sign Test comparing her performance at the end of Phases A and B (p = .O 156).

Walking time, eflciency, and accuracy. Baseline. This task involved her walking between two lines along a 466-cm strip of lino, which was light beige and contrasted well with the dark grey floor. A l2-inch diameter orange circle was hung at eye level on the wall directly ahead of her. It was thought that the tramlines provided by the lino, together with the visual salience of the large target, would enable her to capitalize on any vestiges of localization that remained available to her. Her median walk time at the start of the study, across three trials with the lines and the large target, was I4 seconds (table I). Sixteen female controls obtained a median time of 5 seconds, across three trials each, with a range of 4 to 8 seconds. She had a high-stepping gait during Phase A. She reported that it was the result of her uncertainty about the position of the floor. This is

reflected in table 1, which shows her median number of steps across three trials in the large target condition. At baseline, her median number of steps was 20. This compares with a median of 7 for I6 female controls. The squared surface of the lino allowed the position of her feet to be recorded as she walked, thus giving an index of how accurately she was able to walk in a straight line. About half of her steps were off her direct route at baseline. In contrast, only one of the 16 female controls stepped off the direct route on one trial.

Phase A. The patient’s walking times at baseline and Time A were compared on a Wilcoxon test and were found not to differ significantly (p = .1797). Similarly, the number of steps she took to cover the distance did not differ significantly between baseline and Time A when compared on a Wilcoxon test (p = .2500). The proportion of steps taken off the direct walking route varied considerably during Phase A, however a Wilcoxon test comparing the baseline with time A gave a nonsignificant probability (p = .1088).

Phase B. Slight improvements occurred in her walking performance (table I) and qualitatively she was noted to be using a less hesitant, more normal gait pattern. However, three Wilcoxon tests comparing her performance at the end of phases A and B on the three walking measures gave a nonsignificant probability (for all three, p = .1088).

At the end of phase A, there was no statistically significant change in her performance during the first observation period on any of the specially designed tests of relevant neurologic function. Although there appeared to be a trend for improve- ment on the calibration tests of relevant neurologic function at the end of phase B, only depth perception reached statistical significance.

Neuropsychologic Skills Baseline. She was assessed on three tests of spatial process-

ing from the visual object and space perception battery” (VOSP): cube analysis, position discrimination, and dot count. She was only able to score at an impaired level on all three tests, well below the 5th percentile level of the control samples (ta- ble 2).

Phase A. She repeated the four verbal subtests from the WAIS-R and scored 6 for digit span, 3 for vocabulary and similarities, and 4 for arithmetic. These scores are similar to those reported earlier, which makes it unlikely that any significant improvement in general intellectual level had oc- curred. The three tests of spatial processing from the VOSP were repeated at approximately fortnightly intervals during tire

Table 1: Serial Measures on New Tests of Depth Perception and Walking

Controls Baseline Serial Testing (hpatient) Time A lime B (n= 16P

Depth perception 8” 8 8 8 8 8 8 8 8 (8) 7” 7 8 8 8 8 7 8 8 (8) 6” 8 6 7 8 8 6 8 8 (8) 5” 7 6 7 8 8 7 8 8 (8) 4” 6 5 6 7 8 8 8 8 (8) 3” 8 7 3 8 4 6 8 8 (8) 2” 8 7 3 8 4 6 8 8 (8) 1” 7 6 5 8 8 7 8 8 (8)

Walking (medians of 3 trials1 Number of steps 20 26 20 19 21 19 12 7 w-11) Steps off route 10 12 11 9 16 5 7 0 (0-l) Time in seconds 14 15 13 13 14 13 9 5 (4-8)

* For controls, ranges are also reported (in parentheses).

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Table 2: Serial Measurements on Three Spatial Tasks From the Visual Object and Space Perception Battery

Spatial Task Baseline Serial Testing Time A Time B 5% Cut-Off’

Cube analysis (out of 10) 3 4 4 0 3 6

Dot center (out of20) 13 10 11 8 9 18

Dot count

(out of 10) 2 1 4 2 2 9

l The 5% cut-off scores derived from the healthy standardization samples are given for comparison.

treatment phase, because of the variability of test scores often noted in visual disorientation cases. There was no improving trend or change in level of performance on the spatial tests during Phase A (table 2). and all three remained well within the impaired range.

Phase B. She repeated the four verbal subtests from the WARS-R and scored 6 for digit span, 4 for vocabulary and arithmetic, and 0 for similarities, which once again make it unlikely that any significant improvement in general intellec- tual level had occurred. Her scores on all three of the tests of spatial processing from the VOSP remained at an impaired level (table 2).

Everyday Competence Baseline. At the start of the study, she had just begun to

stand from her bedside chair spontaneously and attempt to walk round her ward. She was able to dress with prompts apart from tying shoe laces, shower with prompts (apart from washing her hair), and had been able to make a snack while standing, again with prompts. Her FIM motor score had increased during the g-week period since she was admitted, from 32 on admission to 65 as the baseline of this study. She still needed constant supervision for all aspects of her daily function, and it was a crucial aim of her rehabilitation program to increase her independence so that she could return home to her husband and young family.

Phase A. She achieved many significant gains in indepen- dent function during the A phase. She achieved the following goals relating to her mobility: she was able to walk through a door frame three times consecutively, she learned to locate the arms of a chair and sit, she learned to get up from the floor, and by the end of her stay at the NRU, she was able to stand unsupported for 5 minutes. In terms of self-care, she achieved the following goals: the hoist was no longer needed for the bath, she learned to transfer in and out of a bath using a bath board and seat with prompts only, independent hairwashing, and finally, a supervised bath using a bath board and seat. Her domestic competence also improved, she learned to move from sitting to standing holding her new baby, to dial and use the telephone unprompted, to make a sandwich and finally a hot drink with supervision. Her FIM motor score improved form 65 at baseline to 81 at Time A. Her level of dependence changed from requiring constant supervision, to being independent for all self-care tasks (apart from requiring supervision for bath- ing), managing simple cold item kitchen tasks independently, and being able to perform some parenting tasks for her new baby.

Phase B. Although she had managed to maintain her treatment gains in independent function during her 3 months at home following her discharge, she had made very little further progress. Her FIM motor score had only changed from 8 1 at the

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end of Phase A. to 83 at the end of Phase B. This lack of change may represent a ceiling effect of the scale.

DISCUSSION We have reported observations from two consecutive time

periods of a person suffering from visual disorientation syn- drome. While an inpatient in a NRU. marked improvements in everyday competence were demonstrated in the context of unchanging scores on both tests of relevant neurologic function and neuropsychology. While at home, little change was ob- served in everyday competence or neuropsychologic test perfor- mance, despite some improvement in neurologic function. We argue that our observations suggest that level of functional disability is not necessarily closely tied to relevant neurologic function or neuropsychologic test scores. Instead. there is a complex and indirect relation among these domains.

We described a 35-year-old woman who demonstrated the classic features of visual disorientation syndrome on both clinical evaluation and formal psychometric assessment. She could not count random scatters of dots, recorded on the VOSP dot count test. She was somewhat unreliable at judging the relative positions of two objects in space from visual input, recorded on a specially devised depth perception task. She could not walk in an efficient, straight line at normal speed, recorded on a specially devised walking test. She also demon- strated another typical feature of visual disorientation syn- drome, that is her ability to locate her own body parts was preserved, and this formed the basis of one of the major therapeutic thrusts of her multidisciplinary rehabilitation pro- gram. She learned to use her hands and other body parts, in contact with objects, as spatial markers for those objects’ positions so that she could locate and manipulate the objects.

During Phase A. she achieved many clinically significant gains in independent function, while her scores on neuropsycho- logic tests remained virtually unchanged and two new tests of relevant neurologic function showed no statistically significant improvement. In contrast during Phase B, few gains in indepen- dent function were achieved. and her scores on neuropsycho- logic tests again remained virtually unchanged, while her performance on some tests of relevant neurologic function showed statistically significant improvement. During Phase A, there was good recovery of independent function (in that her FIM motor score improved from 65 to 81), in the context of unchanging neuropsychology and neurology; yet during Phase B, no significant gains in everyday competence occurred, despite improvement in some relevant neurologic function (depth perception).

Testing of neurologic function focused on aspects of neuro- logic recovery in either visual processing or mobility that might influence everyday competence. It is acknowledged that an improvement on this task might be attributable to a range of factors. However, while it is recognized that a variety of physical and psychological deficits could cause poor perfor- mance on these tasks, they were not designed as diagnostic procedures. The purpose of these tests was to determine whether any improvement in neuropsychology or neurology had occurred that could be underpinning progress in daily activities. It is unlikely that any significant recovery of visual orientation or other related neurologic impairment could occur without improvement of these tasks.

Clearly her spatial processing never approached the normal range of function during the observations reported. The VOSP diagnostic tests of spatial processing are stringent and her spatial processing performance was far below the range across which the diagnostic tests discriminate change. Further mea- sures of spatial competence were required to demonstrate any

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change in function from the severely impaired level at which she performed. The distance judgment task, requiring her to judge canes which varied from 1 to 8 inches apart, showed that her difftculties echoed those of a patient in the study by Holmes and Horrax6 who could not judge which of two objects separated by l5cm was nearest to him. Distance judgment also required spatial processing and some peripheral sensory and motor skills. It follows that changes in either central or peripheral mechanisms could lead to changes in performance on these tests.

The walking tests of speed, accuracy, and step count also focused on a particular disability related to visual disorientation syndrome, that is, walking in a straight line toward a target across a room. For this measure a clear straight path was indicated, thus removing the need to negotiate a path around household objects. Because of expressed uncertainty as to the location of the floor and surrounding walls, in relation to their own bodies, people with visual disorientation syndrome tend to adopt a high-stepping, slow gait with short step length. Any improvement in ability to localize the floor and walls in space would be reflected in a more efficient walking performance. While other neurologic improvements could benefit walking performance, it is unlikely that any neurologic improvement significant enough to facilitate everyday competence would not also result in a measurable improvement on the walking tests.

CONCLUSION The demonstration of improvements in everyday compe-

tence, apparently unrelated to relevant neurologic or neuropsy- chologic recovery, raises the possibility that our patient learned strategies to begin to overcome her cognitive impairments. We are unable to determine whether this was as a direct result of the rehabilitation program that coincided with Phase A. Conclu- sions from any single case study can, at best, be tentative. Yet the rarity and relatively good functional recovery of this patient merit documentation. Simultaneous measures of everyday

function, neuropsychologic test performance, and relevant neurologic function have been reported. They point toward gains in everyday function occurring independently of underly- ing neurologic recovery. Rehabilitation requires an in-depth understanding of this complex neurologic deficit, to allow the development of strategies either to improve primary recovery or to minimize the impact of the deficit on daily life.

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