Case report

Kazuhiro Takimoto,1 Kyohei Omon,1,2 Yuichiro Murakawa,3,4 Hideo Ishikawa5
1

Rehabilitation Center, Eishinkai
Kishiwada Rehabilitation
Hospital, Kishiwada, Osaka,Japan
2
Department of Cognitive
Behavioral Science, Kyoto
University Graduate Schoolof Human and Environmental
Studies, Kyoto, Japan3
Department of Medical Device
Development, mediVR Inc,
Toyonaka, Japan
4
Division of Occupational
Therapy, Department of Human
Health Sciences, Graduate
School of Medicine, Kyoto
University, Kyoto, Japan
5
Hemoptysis and Pulmonary-­
Circulation Center, Eishinkai
Kishiwada Rehabilitation
Hospital, Kishiwada, Osaka,Japan

SUMMARY
A male patient in his 40s was transferred to our hospitalfor rehabilitation of ataxia after right cerebellar andbrainstem infarction. After 3 weeks of conventional
physical therapy, his activities of daily life successfully
improved with an increase in the functional impedance
measure from 101 to 124. However, he still fell shortof gaining a higher level of balance function, which
was necessary for his job as a standup forklift driver.
We introduced virtual reality-­guided balance training.
The training was performed for approximately 40 min
on weekdays for 2 weeks. As a result, the Scale for theAssessment and Rating of Ataxia score decreased from
5 to 1, Functional Balance Scale score improved from 48
to 56, and Mini-­Balance Evaluation Systems Test scoreincreased from 20 to 28. The trunk sway disappeared
clinically. He regained confidence and returned to work
after an additional 2 weeks of physical therapy.

Correspondence to
Mr Kazuhiro Takimoto;​takimoto@​japanscr.​org

BACKGROUND

Accepted 2 May 2021

© BMJ Publishing Group
Limited 2021. Re-­use
permitted under CC BY-­NC. No
commercial re-­use. See rights
and permissions. Publishedby BMJ.
To cite: Takimoto K, Omon K,
Murakawa Y, et al. BMJ Case
Rep 2021;14:e242287.
doi:10.1136/bcr-2021242287

Ataxia is defined as impaired coordination in theabsence of motor paralysis or reduced consciousness, which impedes an individual’s ability toperform voluntary movements, making them
unable to control their direction, force andspeed.1–3 Cerebellar ataxia develops in a majorityof patients with cerebellar stroke, with an estimatedprevalence ranging from 51.3% to 67.5%.4 5 The
loss of balance is one of the critical symptoms of
cerebellar ataxia that should be addressed by active
intervention since it not only causes clumsiness andsluggishness in limb movements but also symptoms
like gait abnormalities can interfere in all aspectsof life, including activities of daily living (ADLs)
and social activities.6 7 Numerous training exercises
to improve balance are available, including stepping, one-­leg standing and ball-­related and disc-­
related exercises; however, they have drawbacks
such as monotony and challenges adjusting difficulty level. For resolving these issues, researchers
overseas have begun to apply virtual reality (VR)technology in rehabilitation programmes targetingbalance impairments; systematic reviews on
VR-­guided training’s effectiveness in improving
balance have already been published after stroke
or in elderly.8 9 However, there is insufficientevidence for the treatment of high-­level balancing
ability in the working generation. In Japan, mediVR
KAGURA, a medical device designed for VR rehabilitation, was approved for clinical use in March
2019.10 11 In this report, we share our experience ofa patient who developed cerebellar ataxia following
a cerebellar/brainstem infarction, whose ataxia andbalance were successfully improved by VR-­guided
rehabilitation using this device.

CASE PRESENTATION

A middle-­aged man in his 40s was affected by aright cerebellar/brainstem infarction. Before thestroke, he had been employed in the warehouselogistics, an environment requiring high levels ofstanding balance for operating forklifts. One day, hesuddenly fell at his residence and was then rushed tothe hospital. On arrival, consciousness disturbance,
persistent gaze deviation, left haemiplegia and rightcerebellar ataxia were noted. Diffusion-­weighted
cranial MRI performed the same day revealed
an infarct in the right cerebellum and brainstem(figure 1). Following acute treatment and care, thepatient was transferred to our hospital on the 37th
day after onset for recovery-­phase rehabilitation.

INVESTIGATIONS

No obvious motor paralysis was noted at the timeof transfer, and he was able to walk unassisted.
However, cerebellar ataxia presenting as a rigid gait
pattern was noted, with the patient locking his (left)
knee during the left stance phase and shuffling thefront of his (left) foot during the left swing phase.
Additionally, during quick stepups, he required
assistance owing to wobbling outside his control.
His ADL performance was rated as ‘independent’for all activities except for transferring and moving,where he was rated as ‘requiring supervision’ forsafety concerns. Early return to work was the rehabilitation need of highest priority, as the patient was
the main provider of his household.

TREATMENTFor the first 3 weeks after admission to our hospital,
the patient underwent a standard physical therapy(PT) programme focusing on balance training(unassisted step ups) and functional gait training(changing direction), with the goal of independent
locomotion without assistance within the facility.
This programme resulted in improved ADL functioning, including an increase in Functional Independence Measure total score from 101 to 124 pts;
however, it did little to improve his coordination
and balance-­related issues (table 1).
Standard PT was supplemented with a voluntary rehabilitation exercise, which employed a VR
medical device (‘VR rehabilitation’ below) initiatingon the 23rd day of inpatient care at our hospital
as a voluntary exercise for this purpose. The VR

Takimoto K, et al. BMJ Case Rep 2021;14:e242287. doi:10.1136/bcr-2021-242287

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Case of cerebellar ataxia successfully treated byvirtual reality-­guided rehabilitation

Case reportrehabilitation device (mediVR KAGURA: mediVR, Toyonaka,
Japan) is capable of presenting an upper limb reaching task toa user seated in three-­dimensional virtual space for the purposeof body balance training; the specific task was a kind of game inwhich the user reaches to make contact with a series of falling
objects (figure 2). VR rehabilitation was introduced to help thepatient regain the level of functional balance needed to return
to his job: namely, the speed, location and the number of falling
objects that were customised to train him how to smoothly
shift his body weight when reaching. The patient underwent
this VR-­guided body balance training for 2 weeks, performing
two 20 min sets per day, 5 days a week. Exercise intensity wascalibrated by adjusting the speeds, locations and numbers offalling objects. Treatment efficacy was assessed by comparing thepatient’s performance on several measures at baseline (admission to our hospital) with those recorded at the initial start of
VR rehabilitation and after the final session. Ataxia was evaluated using the Scale for the Assessment and Rating of Ataxia(SARA). The Functional Balance Scale (FBS) was adopted toassess general balance ability and the Mini-­Balance Evaluation
Systems Test (Mini-­BESTest) to assess more sophisticated high-­
level balance skills.

OUTCOME AND FOLLOW-UP

We followed up with the patient on an outpatient basis andconfirmed a successful return to work.

DISCUSSION

Ataxia can hinder movements in any number of settings, whether
in daily life or social rehabilitation.1–3 Balancing skills are
essential for performing job-­related movements, making theirrecovery an inseparable part of occupational rehabilitation, in
Table 1Figure 2 Visualisation of mediVR KAGURA in use: a medical device
for VR-­guided rehabilitation. The patient is being trained to makesmooth adjustments to his centre of balance as he moves to makecontact with objects falling downward in the virtual space, directly infront of his left hand, and then diagonally in front of his right handusing controllers held in the respective hand (sequence depicted fromleft to right). Blue and red objects must be ‘caught’ with the left andright hand, respectively. VR, virtual reality.
addition to motor palsy and muscle strength. However, it is difficult to state that an effective functional training methodology,
along with supporting evidence, has truly been established totreat ataxia and improve balance skills, especially when it comesto high-­level balancing ability in the working generation.12 Thiscan present a problem in the rehabilitation of patients such as
the present case, where working-­age individuals require a highly
effective yet short-­
term training programme to hasten theirreturn to the workplace. For our case, a standard rehabilitation
programme did not result in sufficient improvement in measuresof ataxia and balance (table 1), despite its targeted content,
an intensive functional training programme lasting 3 weeks
following inpatient admission focused on balance training (unassisted step ups) and functional gait training (changing direction).
We believe that this failure was owing to challenges adjusting
the existing training methods for ataxia and balance skills tolevels matching our patient’s abilities.13 14 This concern led us
to pursue the novel approach of VR-­guided rehabilitation using
a medical device, which has recently been reported effective in
helping patients to recover balance-­related skills after stroke or inelderly.8 9 We believe that some of our patient’s treatment success
was attributed to the effectiveness of VR-­guided rehabilitation
using such a device, as indicated by the record improvements inall assessment scores after VR rehabilitation (SARA, FBS, Mini-­
BESTest) and the patient’s remarks about his recovery. We also
speculate that the software options available to precisely andquantitatively configure the virtual objects’ attributes—including
falling speed, location and count (figure 3) allowed us to resolve
the usual challenges of adjusting task difficulty level encounteredTime-­series data for ataxia and balance measures

Evaluation items

Transfer(for rehabilitation)

First VR session(3 weeks post-­transfer)

After the final VR session(5 weeks post-­transfer)

Discharge(7 weeks post-­transfer)

FIM total score (pts)

101

124

125

126

 Motor subscale

75

90

90

91

 Cognitive subscale

26

34

35

35

 Right

30

33

34

34

 Left

29

34

34

34

SARA (pts)

6

5

1

1

FBS (pts)

48

48

56

56

Mini-­BESTest (pts)

20

20

28

28

FMA-­lower extremity (pts)

FBS, Functional Balance Scale; FIM, Functional Independence Measure; FMA, Fugl-­Meyer Assessment; Mini-­BESTest, Mini-­Balance Evaluation Systems Test; SARA, Scale for the Assessment
and Rating of Ataxia; VR, virtual reality.

2

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Figure 1 Diffusion-­weighted cranial MRI at stroke onset.
Hyperintensities are visible in the right cerebral peduncle and theventral right cerebellar hemisphere in the area of the right anterior
inferior cerebellar artery (A-­C). The patient is diagnosed with rightcerebellar/brainstem infarction.

Case reportin traditional training exercises, leading to the patient’s functional recovery. Although this report is only described a single
case and distinguishing it from a natural course is challenging,
sufficient improvements in SARA, FBS, Mini-­
BESTest after
introduction of VR-­guided rehabilitation implies the utility of it.
Moreover, we believe that the patient’s recovery was assistedby the mediVR KAGURA’s provision of accurate feedback separately for each movement on every task/trial. Specifically, thisdevice provides the user with visual, auditory and haptic feedback when they accurately make contact with a falling object in
the form of text displayed on the screen, sounds and controller
vibrations, respectively. Feedforward control concerning an‘internal model’ has been proposed as a powerful hypothesis formotor control by the cerebellum.15 16 ‘Feedforward learning’, amotor learning process involving the repetition of movements at
appropriate strengths, is considered necessary to the construction of this internal model.2 Patients with cerebellar ataxia
are prone to reduced feedforward control, making accurate,
external feedback necessary for correcting errors, thereby potentiating feedforward learning.2 17 However, some patients might
not be able to gain sufficient feedback from the spoken remarksof therapists (as in standard rehabilitation programmes discussed
above). Our patient’s functional recovery can be explained in theframework of the cerebellar internal model theory as follows.
The patient’s immersion in the VR space permitted sensory
feedback directly, in multiple forms, without any interference
from the external environment. Therefore, this direct feedback
fostered the feedforward learning for target movements better
than conventional rehabilitation exercises. Additionally, several
factors may underlie the mechanism by which seated balance
training contributed to the recovery of standing balance performance: these include the fact that the upper body accounts
for two-­thirds of body mass,10 11 and that the patient’s lower

extremities were naturally activated when he reached far beyond
the base of support while seated in response to the resulting load
placed on them in the direction of motion.11
VR-­
guided rehabilitation is highly reproducible since task
speed and frequency can be precisely calibrated. It also offers
objectivity and convenience, allowing practitioners to adjust thedifficulty level according to an individual’s characteristics andeasily develop and present highly sensitive, accurate and diverse
feedback. The authors have described these benefits in detailabove. Taking full advantage of such next-­generation technologies should expand our range of treatments as therapists, helping
more patients in recovery. Nonetheless, the evidence level forthis VR-­guided rehabilitation programme is a single case report,
indicating that the therapeutic efficacy of such exercises muststill be determined in interventional research such as randomised
controlled trials. Readers should also keep in mind that thepatient in our case presented with a relatively infrequent rigid
gait pattern when interpreting the result. However, cerebellar

Takimoto K, et al. BMJ Case Rep 2021;14:e242287. doi:10.1136/bcr-2021-242287

3

Learning points►► Functional training for patients with cerebellar ataxia canbe difficult in several cases, and the effective therapeuticstrategies should be verified further.
►► Virtual reality (VR)-­guided body balance training can be atherapeutic option for the treatment of cerebellar ataxia.
►► The effectiveness of VR-­guided rehabilitation was indicatedby the record improvements in Scale for the Assessment and
Rating, Functional Balance Scale and Mini-­Balance Evaluation
Systems Test as well as by the patient’s remarks about his
recovery.

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Figure 3 The computer control screen for mediVR KAGURA (in use). The speed, size, location and number of falling objects can be adjusted using
the controls on the left half of the screen. Part of the rendered VR space seen by the patient is displayed on the right half of the screen. VR, virtual
reality.

Case report

Twitter Hideo Ishikawa @2YyKj5lWqFhKDUs
Contributors KT，KO，YM，HI contributed to the conception and design of thiscase report, the acquisition and interpretation of data, and drafting or revising themanuscript critically for important intellectual content.
Funding The authors have not declared a specific grant for this research from any
funding agency in the public, commercial or not-­for-­profit sectors.
Disclaimer Case reports provide a valuable learning resource for the scientificcommunity and can indicate areas of interest for future research. They should not be
used in isolation to guide treatment choices or public health policy.
Competing interests YM is an employee of mediVR, a company that holds
several patents on VR-­guided rehabilitation. KT, KO and HI have no conflicts ofinterest to declare.
Patient consent for publication Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.
Open access This is an open access article distributed in accordance with theCreative Commons Attribution Non Commercial (CC BY-­NC 4.0) license, which
permits others to distribute, remix, adapt, build upon this work non-­commercially,and license their derivative works on different terms, provided the original work
is properly cited and the use is non-­commercial. See: http://​creativecommons.​org/​
licenses/​by-​nc/4​ .​0/.

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lesions typically present with a broad-­based gait.18 19 We anticipate that the promise of the VR-­guided therapeutic intervention
demonstrated in this case report serves to spark interventional
research and foster medical progress in the field of high-­level
designedbalance training of the working generation. Well-­randomised controlled studies are needed to provide us withmore accurate results in the near future.